Skip to content

Patients › Hand

Chấn thương dây chằng UCL ngón cái

Updated Oct 2026
Sơ đồ minh họa tình trạng đứt dây chằng bên trụ ở khớp ngón tay cái.
Đứt dây chằng bên trụ của ngón tay cái (hiện tượng “ngón tay cái của người trượt tuyết”). Kieran Hirpara 4.0

Trang này được dịch bằng máy và chưa được bác sĩ kiểm tra. Bản tiếng Anh là bản chính thức.

Những triệu chứng bạn đang gặp

Chấn thương dây chằng UCL ngón tay cái ảnh hưởng đến dây chằng ở mép trong của ngón tay cái, tại khớp nơi ngón tay cái nối với bàn tay. Chấn thương thường xảy ra khi ngón tay cái bị bẻ mạnh sang một bên, thường là trong một cú ngã chống tay duỗi thẳng. Khi trượt tuyết, chấn thương có thể xảy ra nếu bạn ngã trong lúc vẫn đang nắm gậy trượt tuyết, và người trượt ván tuyết có thể bị chấn thương ngón tay cái khi ngã hoặc khi xoay người.

Cơn đau nằm ở mép trong của ngón tay cái, tại khớp gần lòng bàn tay nhất. Cơn đau thường bắt đầu sau một chấn thương đột ngột, kèm theo sưng và đau khi ấn ở vị trí đó. Kẹp, nắm và bất kỳ động tác nào đẩy ngón tay cái sang một bên đều sẽ gây đau. Những việc hằng ngày tạo lực lên ngón tay cái theo cách này trở nên khó khăn: vặn chìa khóa, mở nắp lọ, cầm một chiếc chảo nặng bằng vành chảo. Ngón tay cái cũng có thể có cảm giác không vững, như thể sẽ bị khuỵu khi bạn ấn nó vào một vật gì đó.

Một số người nhận thấy có một khối nhỏ, cứng ở mép trong của khớp ngón tay cái. Ngón tay cái cũng có thể nằm hoặc xoay hơi lệch so với ngón tay cái bên kia. Nếu chấn thương đã xảy ra từ một thời gian trước, cơn đau có thể ít rõ rệt hơn, nhưng ngón tay cái vẫn có thể có cảm giác yếu hoặc lỏng lẻo khi bạn kẹp hoặc nắm.

Hãy để ý những dấu hiệu sau và xử lý ngay trong ngày: một ngón tay, bàn tay hoặc cánh tay trở nên nóng, đỏ, sưng và đau, đặc biệt khi kèm theo sốt; da bị rách ở vùng khớp bị chấn thương, lộ xương hoặc biến dạng rõ rệt; ngón tay cái hoặc bàn tay trở nên nhợt nhạt, lạnh, trắng bệch hoặc tím tái; hoặc đột ngột mất cảm giác hay mất khả năng cử động sau chấn thương. Những trường hợp này cần được chăm sóc tại khoa cấp cứu ngay lập tức, và không cần giấy giới thiệu của bác sĩ đa khoa.

Nếu các triệu chứng không thuyên giảm, nặng dần lên trong nhiều tuần, làm bạn thức giấc vào ban đêm, hoặc khiến bạn không thể làm việc hay sử dụng bàn tay, hãy đến gặp bác sĩ đa khoa hoặc yêu cầu được bác sĩ chuyên khoa thăm khám.

Chuyện gì đang xảy ra thực sự

Dọc theo mép trong của ngón tay cái, nơi ngón tay cái nối với bàn tay, có một dải dây chằng chắc khỏe gọi là dây chằng bên trụ. Hãy hình dung nó như sợi dây néo giữ vững cột lều: nó ngăn khớp ngón tay cái bị bẻ sang một bên khi bạn kẹp hoặc nắm. Mỗi lần bạn ấn ngón tay cái vào một ngón tay khác, dải dây chằng này chịu lực. Đó là lý do vì sao rách ở đây biểu hiện bằng tình trạng yếu và đau đúng ở những động tác đó.

Khi ngón tay cái bị ép sang một bên, dải dây chằng này có thể bị giãn, rách một phần hoặc rách hoàn toàn. Các bác sĩ phân độ chấn thương theo mức độ rách: giãn hoặc rách một phần, và rách hoàn toàn khi dây chằng bị bong khỏi xương. Đôi khi dây chằng bị rách khỏi xương cùng với một mảnh xương nhỏ. Rách một phần thường có thể lành khi đeo nẹp. Rách hoàn toàn thường không thể tự lành, vì đầu bị rách có thể lật ngược lại và bị kẹt dưới một lớp mô nằm phủ trên khớp. Khi điều đó xảy ra, dây chằng nằm cách xa phần xương mà nó cần bám lại, vì vậy nó không thể tự liền lại.

Nếu vết rách không được điều trị, khớp sẽ vẫn lỏng lẻo. Ngón tay cái tiếp tục bị khuỵu khi chịu lực từ phía bên, và qua nhiều năm, sự di động liên tục đó có thể làm mòn khớp và dẫn đến viêm khớp. Đó là lý do vì sao chấn thương này được xem là nghiêm trọng ngay cả khi nó có cảm giác như một bong gân đơn giản.

Những gì chúng tôi có thể làm

Bác sĩ Kieran Hirpara, bác sĩ phẫu thuật chi trên tại Bệnh viện Mater Private Rockhampton, sẽ lựa chọn phương pháp điều trị phù hợp với chấn thương cụ thể của bạn. Một số trường hợp rách dây chằng ngón tay cái có thể lành mà không cần phẫu thuật, còn những trường hợp khác cần phẫu thuật sớm, vì vậy việc được đánh giá kịp thời rất quan trọng. Thông thường, bệnh nhân được bác sĩ đa khoa giới thiệu đến phòng khám chúng tôi; nếu nhà vật lý trị liệu khuyên bạn nên đến gặp chúng tôi, bạn vẫn cần có giấy giới thiệu từ bác sĩ đa khoa để được hưởng mức hoàn trả chi phí từ Medicare. Tại phòng khám, chúng tôi sẽ hỏi bệnh sử, khám ngón tay cái của bạn và chỉ định chẩn đoán hình ảnh khi cần thiết. Việc này có thể bao gồm chụp X-quang, siêu âm hoặc chụp MRI, một phương pháp dùng nam châm mạnh để chụp những hình ảnh chi tiết của dây chằng. Các phim chụp này cho thấy dây chằng có bị rách hoàn toàn hay không và đầu bị rách có bị lật ra khỏi vị trí hay không.

Nếu vết rách là rách một phần, hoặc dây chằng bị bong khỏi xương cùng với một mảnh xương nhỏ chưa bị di lệch, chúng tôi thường giữ cố định ngón tay cái trong bột trong tối đa 4 tuần. Sau đó, bạn đeo nẹp có thể tháo ra trong 3 tuần tiếp theo và bắt đầu các bài tập cử động nhẹ nhàng. Chuyên gia trị liệu tay của bạn, Ruby Doolan tại Extend Rehabilitation, sẽ hướng dẫn các bài tập này và chế tạo bất kỳ loại nẹp nào bạn cần. Rách hoàn toàn mà đầu bị rách chưa lật ra khỏi vị trí thường được thử điều trị cố định trước, giữ khớp bất động trong 4 đến 6 tuần để dây chằng liền lại.

Phẫu thuật được cân nhắc khi vết rách là hoàn toàn và không vững, khi đầu dây chằng bị rách đã lật ra khỏi vị trí, hoặc khi một mảnh xương đã bị di lệch. Trong những trường hợp này, dây chằng không thể tự lành bám lại vào xương, vì vậy cần phẫu thuật để gắn lại dây chằng. Nếu chấn thương đã xảy ra từ lâu và không thể sửa chữa trực tiếp dây chằng được nữa, chúng tôi có thể tái tạo dây chằng bằng một đoạn gân lấy từ chính cánh tay của bạn hoặc từ mô hiến tặng. Ca phẫu thuật có trang thông tin riêng, và chúng tôi sẽ cùng bạn trao đổi về những gì ca phẫu thuật bao gồm trước khi bạn đưa ra bất kỳ quyết định nào.

Những điều có thể xảy ra

Khi được điều trị, hầu hết các trường hợp rách dây chằng ngón tay cái đều hồi phục tốt. Rách một phần được giữ cố định bằng nẹp hoặc bột thường lành lại, và ngón tay cái lấy lại sức mạnh để kẹp và nắm. Nếu bạn cần phẫu thuật, kết quả nhìn chung là tốt: hầu hết mọi người vẫn giữ được khả năng cử động, lực kẹp và lực nắm của ngón tay cái, và các vấn đề sau phẫu thuật không thường gặp. Những người đã trải qua ca phẫu thuật này đã trở lại chơi thể thao ở mức độ như trước, và các vận động viên chuyên nghiệp đã thi đấu số trận tương đương và có thời gian sự nghiệp tương tự sau đó.

Quá trình hồi phục cần sự kiên nhẫn. Ban đầu ngón tay cái của bạn sẽ được giữ cố định, vì tình trạng cứng khớp sớm là điều chính cần tránh về sau. Khi đã được phép cử động, các bài tập nhẹ nhàng, tăng dần rất quan trọng: việc từ từ tạo lực và kéo giãn dây chằng đang lành giúp cải thiện khả năng cử động và chức năng. Kết quả do bệnh nhân tự đánh giá được cải thiện đáng kể ở thời điểm ba và 12 tháng sau phẫu thuật so với trước phẫu thuật. Nếu chấn thương đã xảy ra từ một thời gian trước, phẫu thuật sửa chữa vẫn có hiệu quả, dù sửa chữa muộn thường khiến bạn mất nhiều khả năng cử động ngón tay cái hơn một chút so với sửa chữa sớm.

Nếu không được điều trị, tiên lượng sẽ khác. Ba trong bốn trường hợp rách hoàn toàn không tự lành, ngay cả khi được nghỉ ngơi. Khớp vẫn lỏng lẻo, ngón tay cái tiếp tục bị khuỵu khi chịu lực, và lực kẹp vẫn yếu và đau. Qua nhiều năm, tình trạng lỏng lẻo liên tục đó làm mòn khớp: 88% những người được sửa chữa muộn một vết rách mạn tính đã có sẵn một mức độ viêm khớp ở khớp ngón tay cái. Tuổi cao hơn tại thời điểm chấn thương có liên quan đến viêm khớp nặng hơn ở khớp đó.

Có một vài điều đáng biết khi bạn lên kế hoạch cho thời gian tới. Nếu ngón tay cái của bạn trở nên nóng, đỏ, sưng và đau, đặc biệt khi kèm theo sốt, hãy đến khoa cấp cứu ngay trong ngày; không cần giấy giới thiệu của bác sĩ đa khoa. Nếu các triệu chứng không thuyên giảm hoặc nặng dần lên trong nhiều tuần, hãy đến gặp bác sĩ đa khoa hoặc yêu cầu được bác sĩ chuyên khoa thăm khám.

Khi nào nên đi khám

Hãy đi khám ngón tay cái sớm sau bất kỳ chấn thương nào làm ngón tay cái bị ép sang một bên, ngay cả khi nó có vẻ chỉ là một bong gân đơn giản. Vết rách hoàn toàn được đánh giá càng sớm, bạn càng có nhiều lựa chọn, vì vết rách để quá lâu có thể cần một ca phẫu thuật lớn hơn hoặc có thể để lại tình trạng cứng và yếu kéo dài. Bạn nên yêu cầu được bác sĩ chuyên khoa thăm khám nếu ngón tay cái vẫn bị khuỵu khi bạn kẹp hoặc nắm, nếu lực kẹp vẫn yếu hoặc đau sau vài tuần, hoặc nếu bạn sờ thấy một khối nhỏ, cứng ở mép trong của khớp. Nếu chấn thương đã xảy ra từ một thời gian trước và ngón tay cái bị lỏng lẻo hoặc đang bị mòn, vẫn nên đi khám để được đánh giá. Và nếu ngón tay cái của bạn trở nên nóng, đỏ, sưng và đau, đặc biệt khi kèm theo sốt, hãy đến khoa cấp cứu ngay trong ngày.

Phân tích chi tiết hơn

Advanced reading: the deeper science (optional)

Phần này đi sâu hơn mức cần thiết để bạn có thể tự đưa ra quyết định điều trị. Chấn thương dây chằng bên ulnar của ngón tay cái là nội dung đáng để đọc thêm; bởi quyết định điều trị hoàn toàn phụ thuộc vào một câu hỏi giải phẫu duy nhất: liệu dây chằng bị rách đã tách ra khỏi vị trí tiếp cận hay chưa. Hiện nay đã có câu trả lời rõ ràng về loại phương pháp chẩn đoán hình ảnh nào nên sử dụng để xác định điều này.

Tổn thương Stener và lý do nó làm thay đổi mọi thứ

Dây chằng bên ulna có chức năng giữ ổn định ngón tay cái trước các lực tác động sang bên trong mọi động tác nắm hay kẹp. Khi dây chằng này bị rách khỏi điểm bám, thông thường nó vẫn nằm ở vị trí có thể lành lại.

Tuy nhiên, đôi khi điều đó không xảy ra. Một lớp gân gọi là màng cân cơ khép nằm phía trên dây chằng; nếu đầu dây chằng bị rách co lại phía trên lớp màng này, màng cân sẽ chèn vào giữa dây chằng và xương. Đó chính là tổn thương Stener, và đây là lý do tại sao chấn thương này được điều trị khác so với hầu hết các trường hợp bong gân: dây chằng không còn tiếp xúc với xương cần để lành lại, vì vậy dù có bó bột cố định thế nào cũng không thể khiến nó tái gắn.

Mọi phương pháp điều trị đều phụ thuộc vào việc tổn thương Stener có xảy ra hay không.

Siêu âm đã đủ để trả lời câu hỏi này

Vì quyết định cần đưa ra mang tính nhị phân và có những hậu quả quan trọng, nên vấn đề liên quan đến chẩn đoán hình ảnh này được xác định rất rõ ràng — và đã có câu trả lời. Trên 422 bệnh nhân, cả siêu âm và MRI đều cho thấy độ chính xác cao trong việc phát hiện các tổn thương Stener; đồng thời siêu âm là phương pháp chẩn đoán hình ảnh thích hợp để sử dụng đầu tiên [1].

Đây là một thông tin hữu ích trong thực hành lâm sàng. Siêu âm nhanh hơn, rẻ hơn và dễ tiếp cận hơn MRI; nếu có bác sĩ thực hiện siêu âm có kinh nghiệm, không cần phải chụp MRI tiếp theo để xác nhận kết quả đã thu được. Ngoài ra, siêu âm còn có tính động: có thể kéo căng ngón tay cái trong lúc thực hiện chụp hình.

Khi không có tổn thương Stener, mức độ lỏng khớp là yếu tố quyết định

Hướng dẫn của Hiệp hội Phẫu thuật Bàn tay Anh Quốc nêu rõ quy trình điều trị. Bệnh nhân bị chấn thương cấp tính cần được đánh giá thông qua tiền sử bệnh, khám lâm sàng và chụp X-quang. Những bệnh nhân không có tình trạng lỏng khớp đáng kể có thể được điều trị không phẫu thuật, trong khi những bệnh nhân có mức độ lỏng khớp đáng kể có thể được điều trị bằng cách cố định không phẫu thuật hoặc phẫu thuật sửa chữa, sau khi đã cùng nhau đưa ra quyết định [2].

Có hai điểm cần lưu ý. Thứ nhất, chụp X-quang được thực hiện trước các phương pháp chẩn đoán hình ảnh nâng cao, một phần nhằm loại trừ khả năng gãy xương bong sụn – tình trạng này lại ảnh hưởng đến phương pháp điều trị. Thứ hai, ngay cả khi có mức độ lỏng khớp đáng kể cũng không nhất thiết phải phẫu thuật: hướng dẫn này nêu rõ đây là quyết định chung giữa việc cố định không phẫu thuật và phẫu thuật sửa chữa; đó là một quan điểm trung thực hơn so với việc coi phẫu thuật là phương án duy nhất.

Tại sao hậu quả của việc chẩn đoán sai lại mang tính đặc thù

Khi dây chằng bên ulnar bị tổn thương nhưng chưa hồi phục hoàn toàn, người bệnh thường không cảm thấy đau khi nghỉ ngơi hay gặp khó khăn trong hầu hết các hoạt động hàng ngày. Tuy nhiên, ngón tay cái sẽ dễ bị lệch hướng khi chịu lực từ phía bên, khiến việc xoay chìa khóa, mở nắp lọ, hoặc cầm nắm vật nặng trở nên khó khăn; nguyên nhân là do lực nắm phụ thuộc vào sự ổn định của ngón tay cái để tạo điểm tựa.

Nếu không được điều trị, tình trạng mất ổn định kéo dài sẽ dẫn đến viêm khớp ở khớp ngón tay cái sau nhiều năm. Đây là lý do vì sao những chấn thương có vẻ chỉ là bong gân đơn thuần cũng cần được đánh giá kỹ lưỡng: hậu quả của việc bỏ sót chẩn đoán không xuất hiện ngay trong vài tuần đầu, khi ngón tay cái dường như đã ổn định, mà chỉ xuất hiện về sau.

Tài liệu tham khảo

[1] Qamhawi Z, Shah K, Kiernan G, Furniss D, Teh J, Azzopardi C. Độ chính xác chẩn đoán của siêu âm và chụp cộng hưởng từ trong việc phát hiện các tổn thương Stener ở ngón tay cái: tổng quan có hệ thống và phân tích tổng hợp. J Hand Surg Eur Vol. 2021;46(9):946-53. https://doi.org/10.1177/1753193421993015

[2] Dean B, Rodrigues J, Riley N, Rabey N, Donnison E, Challen K, và cộng sự. Hướng dẫn điều trị chấn thương dây chằng bên ulnar ngón tay cái: Hiệp hội Phẫu thuật Tay Vương quốc Anh. J Hand Surg Eur Vol. 2024;49(10):1195-201. https://doi.org/10.1177/17531934241274612


Evidence & references

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Overview

Diagnosis and Imaging

  • Ultrasonography has evolved as a reliable adjunct to clinical examination in the evaluation of the ulnar collateral ligament (UCL) of the thumb [1].
  • MRI evaluation reveals greater details enabling better understanding and management of ulnar collateral ligament injuries of the thumb metacarpophalangeal (MCP) joint [2].
  • A 4-stage, treatment-oriented classification of thumb UCL injury is based on the degree of UCL displacement, with correlation with the likelihood of success with either immobilization or operative intervention [10].
  • The presence of a displaced fleck sign has implications for offering surgery to patients with thumb UCL injuries because of a high likelihood of a Stener lesion [17].

Clinical Indications and Natural History

  • Valgus laxity greater than 30 degrees or more than 15 degrees more than in the noninjured thumb with the MCP joint in extension is an indication for operative management [3].
  • Untreated ulnar collateral ligament injury of the thumb metacarpophalangeal joint can lead to long-term pain and functional limitations [5].
  • 75% of cases with complete rupture of the ulnar collateral ligament of the thumb will fail to heal with conservative treatment [13].
  • The rate of surgery for acute thumb MP UCL injury varies based on patient characteristics and the individual treating surgeon [6].

Treatment Outcomes

  • Surgical management of thumb UCL injuries produces overall favorable results [4].
  • Patient-reported outcomes improve significantly at three and 12 months after open surgical repair of the thumb UCL compared to baseline [24].
  • Patients with both acute and chronic thumb UCL injuries have similarly acceptable functional outcomes, postoperative pain, and satisfaction [11].
  • Return-to-play rates after surgical treatment of thumb UCL injuries are high, with reassuring return to preinjury level of play with few complications [9].
  • Thumb ulnar collateral ligament injuries can be safely and effectively managed by football position demands [14].
  • Players who underwent thumb UCL repair played in a similar number of games per season and had similar career lengths in the MLB as controls [16].
  • Treatment of a thumb UCL complete rupture (Grade III) using a custom-made hinged splint shows promise in the conservative management of compliant patients [19].

Surgical Techniques and Rehabilitation

  • A controlled active motion therapy protocol after suture anchor repair of a ruptured UCL of the thumb is safe from a biomechanical point of view [8].
  • Intraosseous suture anchor repair is a safe and effective method for repair of complete tears of the ulnar collateral ligament of the thumb MP joint [12].
  • Both pull-out sutures and bone anchor techniques are safe and effective for treating thumb ulnar collateral ligament injuries [23].
  • Thumb UCL repair with suture tape augmentation demonstrates short-term outcomes comparable to what has been reported for other methods of repair [26].
  • Mini hook plate fixation could be an alternative treatment technique for thumb UCL avulsion fractures [21].
  • The surgical treatment of an ulnar collateral ligament lesion of the thumb using the Fiji Anchor can lead to an excellent clinical outcome with a minor complication rate [48].
  • An accelerated rehabilitation protocol has been clinically applied in athletes following thumb MCP UCL repair with suture tape augmentation [22].
  • The patient is placed in the supine position with a small bump on which to rest the thumb for open repair of the UCL [28].
  • The surgeon should position themselves between the shoulder and head to allow easier access to the ulnar aspect of the thumb during UCL repair [28].
  • A lazy S approach is used on the ulnar aspect of the thumb for UCL repair [28].
  • Careful identification of the radial sensory nerve is required during UCL repair, with prior documentation of sensibility [28].
  • The adductor aponeurosis is incised on the ulnar side during UCL repair [28].
  • The site of rupture for the UCL is identified as distal off the phalanx, midsubstance, or proximal [28].
  • Nonabsorbable suture with pullout button, bone anchors, or figure-of-eight imbrication of midsubstance repair are options for repairing the UCL [28].
  • Motion is limited for the first 4 to 6 weeks depending on chronicity of the injury, with more chronic injuries immobilized longer [28].
  • Guided therapy at 6 weeks in a removable splint is part of the postoperative protocol for UCL repair [28].

Anatomy & Pathophysiology

Bony Anatomy and Joint Mechanics

  • The thumb metacarpophalangeal (MCP) articulation is of a condylar type [52].
  • Flexion of the thumb MCP joint is always accompanied by radial deviation and pronation, which stretches the ulnar metacarpophalangeal ligament [52].
  • The stability of the thumb MCP joint is considered more important than movement from a functional viewpoint [52].
  • The carpometacarpal ray of the thumb is anterior to the plane of the other metacarpals and makes an angle of about 47 degrees with the second ray [52].
  • The distal articular surface of the trapezium is likened to a saddle whose concave curvature lies in a dorsopalmar direction [52].
  • The corresponding surface on the base of the first metacarpal presents a grooved surface in the radioulnar direction [52].
  • The trapeziometacarpal joint has two longitudinal axes and two degrees of freedom [52].
  • The shape of the trapeziometacarpal articular surface does not make for good stability except in anteposition and pronation when the two surfaces are congruent [52].
  • The necessary stability of the trapeziometacarpal joint is provided by a complex ligamentous system which does not limit mobility [52].
  • This ligamentous system essentially consists of a strong ulnar ligament from the base of the first metacarpal to the second metacarpal and to the trapezoid [52].
  • The ulnar ligament of the trapeziometacarpal joint is the structure that resists in a Bennett fracture [52].
  • The radial side of the trapeziometacarpal joint has a much weaker ligament [52].
  • There is an intrinsic instability at the level of the trapeziometacarpal joint where the pressure is very high [52].
  • This pressure is proportional to the force of the grip at the distal end of the thumb and to the length of the lever arm [52].
  • Cooney and Chao (1977) found that joint compression forces during simple pinch averaged 3.0 kg of force at the interphalangeal joint, 5.4 kg at the metacarpophalangeal joint, and 12.0 kg at the carpometacarpal joint [52].
  • Compression forces of up to 120 kg may occur at the carpometacarpal joint during strong grasp [52].
  • Stability of the trapeziometacarpal joint is dynamically provided by a single structure, the tendon of the abductor pollicis longus [52].
  • The abductor pollicis longus tendon has stabilizing function only when the first metacarpal is abducted [52].
  • In adduction, the long abductor increases the risk of subluxation of the trapeziometacarpal joint [52].

Ligamentous Anatomy and Injury Patterns

  • The ulnar collateral ligament (UCL) serves as the primary stabilizer against valgus stress at the thumb MCP joint [20].
  • The UCL plays an essential role in pinch strength, grasping function, and dexterity [20].
  • The mechanism of injury to the UCL is sudden, forced radial deviation (abduction), often resulting from a fall on an outstretched hand with the thumb abducted [44].
  • In skiing, if a person falls while gripping the ski pole, the handle abducts the thumb [44].
  • Associated injuries to UCL tears include tears of the dorsal capsule and ulnar aspect of the volar plate [44].
  • Associated injuries to UCL tears occasionally include a rent in the adductor aponeurosis [44].
  • Volar subluxation of the MCP joint may result from concomitant tears of the dorsal capsule and UCL [44].
  • Distal tears of the UCL at its insertion in the proximal phalangeal base are more common than proximal tears from the metacarpal [44].
  • Ruptures within the substance of the ligament occasionally occur [44].
  • The collateral ligaments of the thumb MP joint afford lateral stability and resist volar subluxation [44].
  • If one collateral ligament is torn, the proximal phalanx tends to rotate volarly on the side of the tear, with the opposite intact ligament serving as the axis [44].
  • In the case of an isolated UCL rupture, the proximal phalanx rotates in supination around the intact radial collateral ligament [44].
  • An avulsion fracture of the ulnar base of the proximal phalanx at the insertion of the ligament is the most common fracture pattern associated with UCL injuries [44].
  • Typically, the avulsion fracture fragment is small and includes little of the articular surface [44].
  • Fractures involving more than 10% of the articular surface can occur and may require fixation if they are displaced 2 mm or more and associated with articular incongruity [44].
  • Avulsion fractures from the metacarpal head and intraarticular shearing fractures of the volar surface of the radial condyle of the metacarpal head have also been reported [44].
  • A rare but potentially problematic fracture pattern involves a rupture of the UCL from the proximal phalanx and a simultaneous articular shear fracture of the proximal phalangeal base [44].
  • In the skeletally immature individual, isolated rupture of the UCL without a Salter fracture of the proximal phalanx is rare but does occur [44].
  • The UCL ruptures off the base of the proximal phalanx [62].
  • The avulsed ligament, with or without a bony fragment, can become displaced above the adductor aponeurosis, preventing healing [62].
  • This displacement is known as a Stener lesion [62].
  • In 25 of 39 patients with complete ruptures of the UCL, Stener found the adductor aponeurosis interposed between the ruptured ulnar collateral ligament and its site of insertion on the base of the proximal phalanx [47].
  • On clinical examination, a prominent lump can be palpated that represents the ulnar collateral ligament being proximally and superficially displaced by the adductor aponeurosis [47].
  • Pathologic rotation of the thumb may be evident in Stener lesions [47].
  • If left uncorrected, a Stener lesion prevents proper healing and leads to chronic instability and subsequent arthrosis [47].
  • Other injuries associated with tears of the UCL include avulsion fractures, dorsal capsular tears, and volar plate tears [47].
  • The adductor aponeurosis interposition prevents direct ligament healing without surgery [42].
  • The UCL is typically avulsed distally [35].
  • Although the injury is often at the distal portion where it attaches to the proximal volar aspect of the phalanx, midsubstance and metacarpal-based tears can occur [35].
  • The anatomic attachment site for a distal avulsion of the UCL is 25% dorsal from the volar surface of the proximal phalanx [94].
  • A single anchor is placed volar to the axis of the joint for distal avulsion repair [94].
  • The radial collateral ligament (RCL) ruptures from its origin, from its insertion, or at the midsubstance [62].
  • RCL ruptures are frequently associated with dorsal or dorsoradial capsular tears and with extensor pollicis brevis avulsions or tears [62].
  • No equivalent of the Stener lesion exists for the RCL [62].
  • RCL ruptures seem susceptible to chronic instability [62].
  • The radial-based abductor cannot create a Stener-type lesion [63].

Pathophysiology and Biomechanics

  • Sequential tearing of the thumb UCL leads to progressive instability of the MCP joint [7].
  • Untreated complete ruptures may result in chronic instability, weakness of pinch, pain, and functional impairment [20].
  • Causes of chronic instability of the UCL include an untreated acute tear, failure to recognize a Stener lesion, or progressive attenuation of the ligament [100].
  • Patients with chronic instability usually present with pain, swelling, and weakness of the involved thumb [100].
  • The pain tends to be exacerbated by forceful pinch and activities requiring torsional motions of the hand, such as unscrewing jar tops [100].
  • Holding large objects like a half-gallon container of milk may be painful and may cause a feeling of instability or lack of power because of the thumb’s inability to resist counterpressure [100].
  • Chronic instability is manifested by gross instability to valgus stress with no endpoint [100].
  • Crepitus with active motion suggests degenerative disease in chronic UCL instability [100].
  • The resting posture of the thumb should be observed for volar subluxation or radial deviation of the MP joint in chronic instability [100].
  • Biomechanically, there are no treatments of repair or reconstruction using native tissues that provide equivalent strength to the preinjured ligament [105].
  • No static ligament reconstruction restores the normal stability characteristics of the thumb UCL [15].
  • Single- and double-bundle UCL reconstructions of the thumb MCP joint have comparable biomechanical properties in regard to joint congruity under valgus load [40].
  • The reconstruction tunnel positioning of triangular configuration with apex proximal stabilizes the thumb MCP joint while maintaining flexion/extension range of motion [60].
  • Although both suture tape and suture anchor constructs recapitulate native joint stiffness, repair with suture tape demonstrated the greatest biomechanical strength in stiffness and load-to-failure [90].
  • In round joints, only the non-anatomic Glickel procedure restores normal range of motion and stability [111].
  • In flat joints, the Glickel procedure and a modified Fairhurst configuration with origins dorsal in the metacarpal head restore range of motion and stability [111].
  • Nonanatomic repositioning of the UCL might affect joint motion [30].
  • Palmar placement of the UCL origin on the metacarpal increased radial deviation from a mean of 18° to a mean of 27° compared with the intact joint [30].
  • Proximal placement of the UCL origin on the metacarpal decreased radial deviation from a mean of 18° to a mean of 10° compared with the intact joint [30].
  • Dorsal placement of the UCL insertion on the phalanx increased radial deviation from a mean of 18° to a mean of 25° compared with the intact joint [30].
  • Distal positioning of the UCL insertion on the phalanx decreased radial deviation from a mean of 18° to a mean of 11° compared with the intact joint [30].
  • Performing a physical examination to assess the amount of instability of an ulnar collateral ligament injury did not create a Stener lesion if the exam was performed in a controlled, gentle manner with the thumb held without rotation [112].
  • It was possible to create a Stener lesion when the thumb was tested in a flexed and supinated position, but only if there was sectioning of the proper UCL, the accessory UCL, and the origin of the ulnar sagittal band at the adductor aponeurosis [112].
  • Supination and flexion of the thumb provided less stability when both components of the UCL were sectioned [112].
  • Pronation and supination play a role in stability of the thumb MCP joint [112].

Classification

  • The BSSH BEST guideline defines significant UCL laxity as no firm endpoint, OR > 20 degrees laxity vs. the other side, OR > 30 degrees laxity [39].
  • The term ‘Stener lesion’ is used to describe when the ligament is completely torn and is displaced superficial to the adductor aponeurosis [18].
  • In a Stener lesion, the ruptured ligament becomes displaced superficial to the adductor aponeurosis and is unable to heal anatomically without surgical intervention [20].
  • Presence of a displaced fleck sign has implications for offering surgery to patients with thumb UCL injuries because of a high likelihood of a Stener lesion [17].

Clinical Presentation

Symptoms and Signs

  • Patients commonly report pain, swelling, and ecymosis around the thumb metacarpophalangeal joint [47].
  • Tenderness is greatest over the ulnar aspect of the thumb metacarpophalangeal joint [47].
  • A prominent lump can be palpated representing the ulnar collateral ligament being proximally and superficially displaced by the adductor aponeurosis in the presence of a Stener lesion [47].
  • Pathologic rotation of the thumb may be evident in cases of Stener lesion [47].
  • Incomplete acute tears and nondisplaced avulsion fractures are managed with a thumb spica cast for up to 4 weeks, followed by removable protective splinting for 3 more weeks with active range-of-motion exercises [42].
  • Skier's thumb can lead to chronic pain and instability when diagnosed incorrectly [83].

Clinical Examination

  • The metacarpophalangeal joint is generally examined by applying a radial force in extension and with approximately 30° of MCPJ flexion to relax the palmar plate [18].
  • Physical examination is performed with a valgus stress applied in neutral rotation to the thumb in both extension (testing the accessory ligament) and 30° to 35° flexion (proper ligament) [42].
  • An injured thumb that shows more than 30 degrees of instability compared with the uninjured side indicates a complete rupture [47].
  • Valgus instability of more than 30°—or more than 10° compared with the contralateral thumb in both flexion and extension—indicates complete rupture of the proper and accessory UCL [80].
  • Instability of the MCP joint in flexion indicates rupture of the proper UCL only [80].
  • Comparison with the uninjured contralateral thumb is unreliable in many individuals due to significant variation between right and left thumbs [32].
  • New evidence suggests that a lack of definite end point rather than comparison with the uninjured side should be used to define complete UCL rupture [42].
  • If a hard endpoint is not encountered and there is increased deviation (>20 degrees) at the MP joint, surgery is recommended [35].
  • For those patients with significant guarding, a digital block may be necessary to carry out the stress test [35].
  • The ulnar side of the joint should be palpated for a Stener lesion, where both the proper and accessory ligament are retracted and lie on the adductor aponeurosis [42].
  • Physical examination is required to determine stability with injuries to the ulnar structures of the thumb metacarpophalangeal joint [31].
  • Clinical examination is recommended to assess for significant laxity of the UCL, defined as no firm endpoint, or > 20 degrees laxity vs. the other side, or > 30 degrees laxity [39].

Imaging and Diagnostic Tests

  • Plain radiographs should be obtained prior to any stress examinations to avoid displacing an otherwise nondisplaced fracture [42].
  • Plain radiographs should be obtained prior to any stress examinations to exclude obvious fractures and dislocation or subluxation [58].
  • Anteroposterior stress radiographs can be obtained of both thumbs for comparison purposes [47].
  • Stress radiographs are useful for identifying Stener lesions, however, these are often uncomfortable for the patient and guarding may lead to false-negative results [42].
  • Fluoroscopy can aid the diagnosis to see if the joint becomes incongruent and to measure the deviation compared to the contralateral limb [35].
  • Ultrasonography has evolved as a reliable adjunct to clinical examination in evaluation of the UCL of the thumb [1].
  • MRI evaluation reveals greater details enabling better understanding and management of ulnar collateral ligament injuries of the thumb MCP joint [2].
  • Ultrasound had a positive predictive value for rupture of 94% when compared with the operative finding [58].
  • The overall agreement between specialist clinic examination and ultrasound for injury to the ulnar collateral ligament was 85% (kappa 0.647) [58].
  • Senior House Officers in the A&E department were able to correctly diagnose only 45% of the ruptures of the ulnar collateral ligament [58].
  • In a study of 49 patients, ultrasound identified Stener lesions with a sensitivity of 36% and specificity of 61% [51].
  • MRI and US of suspected UCL injury did not demonstrate good enough sensitivity for the authors to recommend their implementation and use in clinical situations [51].
  • A magnetic resonance imaging scan is recommended for additional preoperative planning because it provides a detailed assessment of tear location, injury grade, and ligament quality [80].
  • Clinical assessment of a thumb ulnar collateral ligament injury should be supplemented with radiographs, as underlying pathology, such as an enchondroma, may be a factor [61].

Investigations

Clinical Examination

  • The MCP joint is generally examined by applying a radial force in extension and with approximately 30° of MCP joint flexion to relax the palmar plate, which is thought to isolate the UCL proper [18].
  • Careful stress testing of the injured and uninjured side in both extension and flexion can often elucidate those with a significant tear of their UCL/RCL [35].
  • The absence of a normal “endpoint” with radial stress is a key diagnostic finding signifying a complete ligament tear [35].
  • For patients with significant guarding, a digital block may be necessary to carry out the stress test [35].
  • Patients with a soft endpoint, incongruent joint, or Stener lesion require surgical intervention [35].

Imaging

  • Ultrasonography (US) has evolved as a reliable adjunct to clinical examination in evaluation of the UCL of the thumb [1].
  • Diagnostic ultrasound is a useful, noninvasive tool for assessing the extent of rupture of the ulnar collateral ligament [114].
  • Ultrasound or MRI can be helpful to gather more information when it is difficult to ascertain if there is a Stener lesion based on palpation [35].
  • Ultrasound and MRI findings do not have 100% accuracy and their findings should only be one component of the decision-making algorithm [35].

Treatment

Non-Operative Management

  • A thumb spica cast or functional brace is recommended for 4 to 6 weeks for incomplete ruptures of the ulnar collateral ligament [47].
  • Tears of the UCL of the thumb MCP joint without a Stener lesion are believed to heal with 4 to 6 weeks of immobilization [62].
  • In patients having less than 30 degrees of laxity of the UCL, less than a 15-degree differential in laxity compared with the contralateral side, and a discrete endpoint to joint opening, nonoperative treatment consists of immobilization of the MP joint for 4 weeks in neutral alignment and slight flexion [104].
  • Untreated ulnar collateral ligament (UCL) injury of the thumb metacarpophalangeal joint can lead to long-term pain and functional limitations [5].

Indications for Surgery

  • Injuries that are unstable (usually 30° more opening with radial stress than the opposite uninjured side) are believed to have Stener lesions and are treated surgically [62].
  • Complete tears require open repair with suture anchors or bone tunnels placed at the site of the avulsion, which most commonly is the proximal phalanx [42].
  • The tear will not heal in the setting of a Stener lesion because of adductor aponeurosis interposition [42].
  • Acute complete rupture of the ulnar collateral ligament should be surgically repaired [47].
  • Ulnar collateral ligament retraction more than 3 mm and interposed soft tissue are reasonable guides to surgical intervention [47].

Operative Techniques

  • Repair of the UCL of the thumb is one of the most common ligamentous repairs in the hand, with options including a pullout suture and button, bone anchors, or a combination of the two with local tissue augmentation or imbrication [63].
  • A K-wire across the joint is often employed to allow proper ligament tensioning and to maintain joint stability postoperatively [63].
  • The surgical approach involves a lazy S incision on the ulnar aspect of the thumb, with careful identification and retraction of the dorsal sensory branch of the radial nerve [28].
  • The adductor aponeurosis is incised longitudinally to allow repair after the collateral ligament repair [28].
  • Direct repair of the ligament should be obtained with the use of one or two bone anchors, preferably small metallic anchors with stout nonabsorbable suture material [35].
  • Additional sutures are used to augment the repair to the volar plate distally and capsule dorsally [35].
  • The capsule and adductor aponeurosis should be repaired in separate layers [35].
  • For chronic tears with excessive laxity, the adductor insertion can be advanced to increase dynamic stability [35].
  • Both pull-out suture and bone anchor techniques are safe and effective for treating thumb ulnar collateral ligament injuries [23].
  • In a biomechanical model, thumb UCL repair with suture tape augmentation demonstrated greater maximum and clinical failure loads compared with nonaugmented repair at time 0 [41].
  • Arthroscopic treatment of acute complete thumb metacarpophalangeal ulnar collateral ligament tears resulted in key pinch, tip pinch, grip strength, and range of motion equal to or greater than in the thumb on the unaffected side in most cases [46].

Chronic Injury and Reconstruction

  • If the diagnosis is delayed for 1 month or longer, fibrosis makes ligament identification and repair more difficult, although repair can be done by dissecting out the ligament from within the fibrotic mass and reattaching it appropriately [47].
  • The detached tendinous insertion of the adductor muscle can be advanced and reattached to furnish a dynamic reinforcement in delayed repairs [47].
  • If the repair is done several months after the injury, a graft can be used [47].
  • Chronic ruptures of the UCL can be challenging to reconstruct, but most often there is enough local tissue present to allow for direct repair with the existing native ligament [35].
  • Graft reconstruction of the UCL can often be accomplished with either an autograft palmaris/plantaris tendon or with an allograft [35].
  • Newer techniques for chronic reconstruction involve the use of 3.0-mm drills, the graft, fibertape, and interference screws [35].
  • An X or Y type configuration is often needed to appropriately reconstruct the surface area of the ligament to prevent recurrent instability in chronic cases [35].
  • If a Y construct is used for chronic reconstruction, the single limb is placed distally and the dual limb proximally to prevent iatrogenic injury [35].
  • A K-wire is highly recommended in chronic reconstruction to allow adequate healing and provide sufficient stability to permit early mobilization of the adjacent IP and CMC joints [35].
  • The pin is typically removed in the office at 6 weeks following chronic reconstruction [35].
  • Nonbiological ligament reconstruction of the thumb ulnar collateral ligament generates short-term outcomes comparable with those of biological reconstruction, potentially allowing for expedited recovery and rehabilitation [45].
  • Patient-reported outcomes, including pain and function, improved after thumb UCL reconstruction with a tendon autograft [36].
  • Increased time from injury to treatment (beyond 6 weeks) may decrease the likelihood of direct repair [104].
  • If no local tissue is available for chronic repair, UCL reconstruction is most commonly performed with a free tendon graft [104].
  • The graft is tensioned at 45 degrees of flexion with some ulnar deviation placed on the MCP joint during reconstruction [104].
  • A relative contraindication to ligament reconstruction is marked volar subluxation and/or supination of the MP joint [104].
  • The only absolute contraindication to reconstruction is osteoarthritis of the MP joint, in which case arthrodesis is a very dependable option [104].

Outcomes and Rehabilitation

  • Collegiate football athletes treated for thumb UCL injuries with suture anchor repair had quick return to play, reliable return to the same level of activity, and excellent long-term clinical outcomes [33].
  • Complications are rare and most patients show preservation of motion, key pinch, and grip strength [25].
  • Thumb MCP joint collateral ligament injuries have a good outcome with appropriate diagnosis and treatment [34].
  • There was no significant change in pinch strength in patients with chronic UCL reconstructions, but significantly better results were achieved in grip strength, flexion, extension, ulnar and radial deviation [29].
  • This is the first clinical application of an accelerated rehabilitation protocol in athletes following thumb MCP UCL repair [22].
  • Strenuous activity is avoided for 3 months, with unrestricted return to sport usually at 2 to 3 months [42].
  • Limit motion for the first 4 to 6 weeks depending on chronicity of the injury; more chronic injuries are immobilized longer [28].
  • Guided therapy at 6 weeks in a removable splint is part of the postoperative protocol [28].
  • A thumb spica cast is worn for 4 weeks postoperatively after reconstruction, followed by hand therapy and protection for an additional 5 weeks in a splint [104].

Complications

Non-Operative

Operative

  • Long-term dangers and the cost effectiveness of the procedure using the Fiji Anchor® are not known yet [48].
  • Thumb spica casting risks placing additional stress upon adjacent joints and causing adjacent injury [37].

Recovery

Outcomes and Function

  • Recovery of pinch grip strength measured using two point palmar pinch is on average within 92 per cent of expected values after normalization for dominance [66].

Return to Sport and Work

  • Players who underwent thumb UCL surgery played in a similar number of games per season and had similar career lengths in the NFL as controls [67].

Rehabilitation Protocols

Key Evidence

  • [L4] Ultrasonography (US) has evolved as a reliable adjunct to clinical examination in evaluation of the UCL of the thumb. [1] (10.1148/rg.264055117)
  • [L4] MRI evaluation reveals greater details enabling better understanding and management of ulnar collateral ligament injuries of the thumb MCP joint. [2] (10.1016/s0363-5023(09)60139-8)
  • [L5] Valgus laxity greater than 30 degrees or more than 15 degrees more than in the noninjured thumb with the MCP joint in extension is an indication for operative management. [3] (10.5435/00124635-199707000-00006)
  • [L1] Surgical management of thumb UCL injuries produces overall favorable results. [4] (10.5435/jaaosglobal-d-25-00082)
  • [L5] Untreated ulnar collateral ligament (UCL) injury of the thumb metacarpophalangeal joint can lead to long-term pain and functional limitations. [5] (10.2106/jbjs.k.01024)
  • [L3] The rate of surgery for acute thumb MP UCL injury varies based on patient characteristics and the individual treating surgeon. [6] (10.1177/1558944716681974)
  • [L5] Sequential tearing of the thumb UCL leads to progressive instability of the MCP joint. [7] (10.1177/1558944719868518)
  • [L5] A controlled active motion therapy protocol after suture anchor repair of a ruptured UCL of the thumb is safe from a biomechanical point of view. [8] (10.1016/j.jhsa.2004.04.017)
  • [L4] Return-to-play rates after surgical treatment of thumb UCL injuries are high, with reassuring return to preinjury level of play with few complications. [9] (10.1016/j.jhsg.2023.03.005)
  • [L4] Our 4-stage, treatment-oriented classification of thumb UCL injury is based on the degree of UCL displacement, with correlation with the likelihood of success with either immobilization or operative intervention. [10] (10.1016/j.jhsa.2014.08.033)
  • [L3] Patients with both acute and chronic thumb UCL injuries have similarly acceptable functional outcomes, postoperative pain, and satisfaction. [11] (10.1016/j.jhsg.2022.02.008)
  • [L3] The authors concluded that this is a safe and effective method for repair of complete tears of the ulnar collateral ligament of the thumb MP joint. [12] (10.1016/s0363-5023(97)80113-x)
  • [L5] 75% of cases with complete rupture of the ulnar collateral ligament of the thumb will fail to heal with conservative treatment. [13] (10.1007/s11552-008-9145-8)
  • [L4] Thumb ulnar collateral ligament injuries can be safely and effectively managed by football position demands. [14] (10.1177/2325967114s00092)
  • [L5] No static ligament reconstruction restores the normal stability characteristics of the thumb UCL. [15] (10.1016/j.jhsa.2004.09.012)
  • [L3] Players who underwent thumb UCL repair played in a similar number of games per season and had similar career lengths in the MLB as controls. [16] (10.1177/2325967117747268)
  • [L4] Presence of a displaced fleck sign has implications for offering surgery to patients with thumb UCL injuries because of a high likelihood of a Stener lesion. [17] (10.1016/j.jhsa.2024.12.003)
  • [L1] [18] (10.1177/17531934241274612)
  • [L4] Treatment of a thumb UCL complete rupture (Grade III) using a custom-made hinged splint shows promise in the conservative management of compliant patients. [19] (10.1016/j.jht.2009.10.001)
  • [L4] [20] (10.1016/j.injury.2026.113711)
  • [L4] It could be an alternative treatment technique for thumb UCL avulsion fractures. [21] (10.1016/j.otsr.2019.01.008)
  • [L4] This is the first clinical application of an accelerated rehabilitation protocol in athletes following thumb MCP UCL repair. [22] (10.1016/j.jht.2022.07.007)
  • [L3] Both repair methods are safe and effective for treating thumb ulnar collateral ligament injuries. [23] (10.1097/prs.0b013e3181882163)
  • [L2] Patient-reported outcomes improve significantly at three and 12 months after open surgical repair of the thumb UCL compared to baseline. [24] (10.1016/j.jhsa.2023.05.003)
  • [L5] Complications are rare and most patients show preservation of motion, key pinch, and grip strength. [25] (10.1016/j.ocl.2014.11.007)
  • [L4] Thumb UCL repair with suture tape augmentation demonstrates short-term outcomes comparable to what has been reported for other methods of repair. [26] (10.1142/s2424835520500046)
  • [L3] There was no significant change in pinch strength in patients with chronic UCL reconstructions, but significantly better results were achieved in grip strength, flexion, extension, ulnar and radial deviation. [29] (10.1016/j.hansur.2020.03.002)
  • [L5] [30] (10.1053/jhsu.1999.0283)
  • [L5] This suggests that physical examination is required to determine stability with injuries to the ulnar structures of the thumb metacarpophalangeal joint. [31] (10.1016/s0363-5023(98)80158-5)
  • [L4] Comparison with the uninjured contralateral thumb is unreliable in many individuals due to significant variation between right and left thumbs. [32] (10.1177/1753193408100957)
  • [L4] Collegiate football athletes treated for thumb UCL injuries with suture anchor repair had quick return to play, reliable return to the same level of activity, and excellent long-term clinical outcomes. [33] (10.1016/j.jhsa.2014.06.132)
  • [L5] Thumb MCP joint collateral ligament injuries have a good outcome with appropriate diagnosis and treatment. [34] (10.1016/j.csm.2014.09.004)
  • [L4] Patient-reported outcomes, including pain and function, improved after thumb UCL reconstruction with a tendon autograft. [36] (10.1016/j.jhsa.2024.05.005)
  • [L4] Thumb spica casting protects the surgically repaired thumb UCL and allows for earlier return to play, but risks placing additional stress upon adjacent joints and causing adjacent injury. [37] (10.1177/1558944718788644)
  • [L5] [39] (10.1177/17531934241311826)
  • [L5] Single- and double-bundle UCL reconstructions of the thumb MCP joint have comparable biomechanical properties in regard to joint congruity under valgus load. [40] (10.1177/1558944717744338)
  • [L5] In this model, thumb UCL repair with suture tape augmentation demonstrated greater maximum and clinical failure loads compared with nonaugmented repair at time 0, that is, without any biological healing. [41] (10.1016/j.jhsa.2018.02.002)
  • [L4] Nonbiological ligament reconstruction of the thumb ulnar collateral ligament generates short-term outcomes comparable with those of BLR, potentially allowing for expedited recovery and rehabilitation. [45] (10.1016/j.jhsa.2024.01.008)
  • [L4] In most cases, key pinch, tip pinch, grip strength, and range of motion were equal to or greater than in the thumb on the unaffected side. [46] (10.1016/s0363-5023(05)80156-x)
  • [Paper] The surgical treatment of an ulnar collateral ligament lesion of the thumb using the Fiji Anchor® can lead to an excellent clinical outcome with a minor complication rate; however, long-term dangers and the cost effectiveness of the procedure are not known yet. [48] (10.1007/s00402-020-03625-x)
  • [L4] [51] (10.1177/1753193420932496)
  • [L2] [58] (10.1054/jhsb.1999.0283)
  • [L5] The reconstruction tunnel positioning of triangular configuration with apex proximal stabilizes the thumb MCP joint while maintaining flexion/extension range of motion. [60] (10.1016/j.jhsa.2005.05.004)
  • [L5] This case highlights that clinical assessment of a thumb ulnar collateral ligament injury should be supplemented with radiographs, as underlying pathology, such as an enchondroma, may be a factor. [61] (10.1177/17531934251315313)
  • [L4] Recovery of pinch grip strength measured using two point palmar pinch is on average within 92 per cent of expected values after normalization for dominance. [66] (10.1016/0020-1383(94)90179-1)
  • [L4] Players who underwent thumb UCL surgery played in a similar number of games per season and had similar career lengths in the NFL as controls. [67] (10.1177/1558944718760001)
  • [L5] [80] (10.1016/j.eats.2025.103957)
  • [L5] Skier's thumb is an often-encountered injury and can lead to chronic pain and instability when diagnosed incorrectly. [83] (10.1186/1865-1380-6-31)
  • [L5] Although both ST and SA constructs recapitulate native joint stiffness, repair with ST demonstrated the greatest biomechanical strength in stiffness and load-to-failure. [90] (10.1016/j.jhsa.2021.09.028)
  • [L5] Biomechanically, there are no treatments of repair or reconstruction using native tissues that provide equivalent strength to the preinjured ligament. [105] (10.5435/jaaos-d-22-00112)
  • [L5] In round joints, only the non-anatomic Glickel procedure restores normal ROM and stability, while in flat joints, the Glickel procedure and a modified Fairhurst configuration with origins dorsal in the metacarpal head restore ROM and stability. [111] (10.1177/17531934231164260)
  • [L5] [112] (10.1142/s0218810417500411)
  • [L5] Diagnostic ultrasound is a useful, noninvasive tool for assessing the extent of rupture of the ulnar collateral ligament. [114] (10.1016/0363-5023(94)90025-6)

References

[1] US Diagnosis of UCL Tears of the Thumb and Stener Lesions: Technique, Pattern-based Approach, and Differential Diagnosis. RadioGraphics. 2006. DOI: 10.1148/rg.264055117

[2] MRI Classification of Ulnar Collateral Ligament Injuries of the Thumb MCP Joint. The Journal of Hand Surgery. 2009. DOI: 10.1016/s0363-5023(09)60139-8

[3] Injuries to the Ulnar Collateral Ligament of the Thumb Metacarpophalangeal Joint. Journal of the American Academy of Orthopaedic Surgeons. 1997. DOI: 10.5435/00124635-199707000-00006

[4] Surgical Management of Thumb Ulnar Collateral Ligament Injuries: A Systematic Review and Meta-analysis of 614 Patients With a Minimum 1 Year Follow-up. JAAOS: Global Research and Reviews. 2025. DOI: 10.5435/jaaosglobal-d-25-00082

[5] Management of Thumb Metacarpophalangeal Ulnar Collateral Ligament Injuries. Journal of Bone and Joint Surgery. 2012. DOI: 10.2106/jbjs.k.01024

[6] Variation in the Rate of Surgery for Ulnar Collateral Ligament Injury of the Metacarpophalangeal Joint of the Thumb. HAND. 2016. DOI: 10.1177/1558944716681974

[7] Biomechanical Analysis of Thumb Ulnar Collateral Ligament Tear Kinematics. HAND. 2019. DOI: 10.1177/1558944719868518

[8] A biomechanical modeling of injury, repair, and rehabilitation of ulnar collateral ligament injuries of the thumb. The Journal of Hand Surgery. 2004. DOI: 10.1016/j.jhsa.2004.04.017

[9] Return to Play After Thumb Ulnar Collateral Ligament Injuries Managed Surgically in Athletes—A Systematic Review. Journal of Hand Surgery Global Online. 2023. DOI: 10.1016/j.jhsg.2023.03.005

[10] Gamekeeper’s Thumb—A Treatment-Oriented Magnetic Resonance Imaging Classification. The Journal of Hand Surgery. 2015. DOI: 10.1016/j.jhsa.2014.08.033

[11] A Comparison of Acute Versus Chronic Thumb Ulnar Collateral Ligament Surgery Using Primary Suture Anchor Repair and Local Soft Tissue Advancement. Journal of Hand Surgery Global Online. 2022. DOI: 10.1016/j.jhsg.2022.02.008

[12] Repair of acute ulnar collateral ligament injuries of the thumb metacarpophalangeal joint with an intraosseous suture anchor. The Journal of Hand Surgery. 1997. DOI: 10.1016/s0363-5023(97)80113-x

[13] Injury to the Ulnar Collateral Ligament of the Thumb. HAND. 2008. DOI: 10.1007/s11552-008-9145-8

[14] Return to Play and Long-Term Clinical Outcomes after Suture Anchor Repair of Thumb Ulnar Collateral Ligament Injuries in Collegiate Football Athletes. Orthopaedic Journal of Sports Medicine. 2014. DOI: 10.1177/2325967114s00092

[15] Reconstruction of the ulnar collateral ligament of the thumb metacarpophalangeal joint: A cadaver study. The Journal of Hand Surgery. 2005. DOI: 10.1016/j.jhsa.2004.09.012

[16] Performance and Return to Sport After Thumb Ulnar Collateral Ligament Repair in Major League Baseball Players. Orthopaedic Journal of Sports Medicine. 2018. DOI: 10.1177/2325967117747268

[17] The Displaced Fleck Sign: Description of a Radiographic Finding Consistent with Grade III Thumb Ulnar Collateral Ligament Tears with Stener Lesions. The Journal of Hand Surgery. 2025. DOI: 10.1016/j.jhsa.2024.12.003

[18] Guideline on managing thumb ulnar collateral ligament injuries: the British Society of Surgery for the Hand Evidence for Surgical Treatment (BEST) findings and recommendations. Journal of Hand Surgery (European Volume). 2024. DOI: 10.1177/17531934241274612

[19] Treatment of Grade III Thumb Metacarpophalangeal Ulnar Collateral Ligament Injuries with Early Controlled Motion Using a Hinged Splint. Journal of Hand Therapy. 2010. DOI: 10.1016/j.jht.2009.10.001

[20] Return to Duty After Suture Anchor Repair of Thumb Metacarpophalangeal Ulnar Collateral Ligament Injuries in Active Duty Soldiers. Injury. 2026. DOI: 10.1016/j.injury.2026.113711

[21] Mini hook plate fixation for thumb ulnar collateral ligament avulsion fracture: A technical report. Orthopaedics & Traumatology: Surgery & Research. 2019. DOI: 10.1016/j.otsr.2019.01.008

[22] Accelerated rehabilitation following thumb ulnar collateral ligament repair with suture tape augmentation: A case series of professional basketball players. Journal of Hand Therapy. 2023. DOI: 10.1016/j.jht.2022.07.007

[23] Repair of Acute Ulnar Collateral Ligament Injuries of the Thumb Metacarpophalangeal Joint: A Retrospective Comparison of Pull-Out Sutures and Bone Anchor Techniques. Plastic and Reconstructive Surgery. 2008. DOI: 10.1097/prs.0b013e3181882163

[24] Patient-Reported Outcomes and Function After Surgical Repair of the Ulnar Collateral Ligament of the Thumb. The Journal of Hand Surgery. 2023. DOI: 10.1016/j.jhsa.2023.05.003

[25] Ulnar Collateral Ligament Injuries of the Thumb. Orthopedic Clinics of North America. 2015. DOI: 10.1016/j.ocl.2014.11.007

[26] Thumb Ulnar Collateral Ligament Repair with Suture Tape Augmentation. The Journal of Hand Surgery (Asian-Pacific Volume). 2020. DOI: 10.1142/s2424835520500046

[28] Rockwood And Green S Fractures In Adults. 42: Fractures of the Distal Radius and Ulna > Open Repair of the Ulnar or Radial Collateral Ligament of the MCP Joint of the Thumb: Preoperative Planning Checklist.

[29] The effects of rehabilitation on the outcomes of surgically treated acute and chronic thumb metacarpophalangeal ulnar collateral ligament ruptures. Hand Surgery and Rehabilitation. 2020. DOI: 10.1016/j.hansur.2020.03.002

[30] The effect of thumb metacarpophalangeal ulnar collateral ligament attachment site on joint range of motion: An in vitro study. The Journal of Hand Surgery. 1999. DOI: 10.1053/jhsu.1999.0283

[31] The stener lesion revisited: A case report. The Journal of Hand Surgery. 1998. DOI: 10.1016/s0363-5023(98)80158-5

[32] Clinical Testing of Ulnar Collateral Ligament Injuries of the Thumb. Journal of Hand Surgery (European Volume). 2009. DOI: 10.1177/1753193408100957

[33] Return to Football and Long-Term Clinical Outcomes After Thumb Ulnar Collateral Ligament Suture Anchor Repair in Collegiate Athletes. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2014.06.132

[34] Thumb Ulnar Collateral and Radial Collateral Ligament Injuries. Clinics in Sports Medicine. 2015. DOI: 10.1016/j.csm.2014.09.004

[35] Rockwood And Green S Fractures In Adults. 42: Fractures of the Distal Radius and Ulna > Thumb MCP Ligament Repair.

[36] Patient-Reported and Clinical Outcomes After Tendon Autograft Reconstruction of the Thumb Ulnar Collateral Ligament. The Journal of Hand Surgery. 2025. DOI: 10.1016/j.jhsa.2024.05.005

[37] Early Return to Play With Thumb Spica Gauntlet Casting for Ulnar Collateral Ligament Injuries Complicated by Adjacent Joint Dislocations in Collegiate Football Linemen. HAND. 2018. DOI: 10.1177/1558944718788644

[39] Re. Dean B, Rodrigues J, Riley N, Rabey N, Donnison E, Challen K, Bradford S; BSSH BEST UCL Guideline Development Group. Guideline on managing thumb ulnar collateral ligament injuries: the British Society of Surgery for the Hand Evidence for Surgical Treatment (BEST) findings and recommendations. J Hand Surg Eur. 2024, 49: 1195–201. Journal of Hand Surgery (European Volume). 2025. DOI: 10.1177/17531934241311826

[40] Single-Bundle vs Double-Bundle (Anatomical) Reconstruction of the Thumb Ulnar Collateral Ligament: Biomechanical Study. HAND. 2017. DOI: 10.1177/1558944717744338

[41] Suture Tape Augmentation of the Thumb Ulnar Collateral Ligament Repair: A Biomechanical Study. The Journal of Hand Surgery. 2018. DOI: 10.1016/j.jhsa.2018.02.002

[42] Orthopaedic Knowledge Update Sports Medicine 6. Hand and Wrist Injuries > Hand Injuries > Skier’s Thumb.

[44] Green S Operative Hand Surgery. Dislocations and Ligament Injuries of the Digits > Acute Ulnar Collateral Ligament Injuries (Skier’s Thumb).

[45] Biological Versus Nonbiological Reconstruction of the Ulnar Collateral Ligament of the Thumb Metacarpophalangeal Joint: A Retrospective Study. The Journal of Hand Surgery. 2024. DOI: 10.1016/j.jhsa.2024.01.008

[46] Arthroscopic treatment of acute complete thumb metacarpophalangeal ulnar collateral ligament tears. The Journal of Hand Surgery. 1995. DOI: 10.1016/s0363-5023(05)80156-x

[47] Campbell S Operative Orthopaedics 4 Volume Set. FRACTURES, DISLOCATIONS, AND LIGAMENTOUS INJURIES OF THE HAND AND WRIST > THUMB METACARPOPHALANGEAL JOINT ULNAR COLLATERAL LIGAMENT RUPTURE.

[48] Clinical results of the BoneWelding®Fiji® anchor for the treatment of Stener lesions of the thumb. Archives of Orthopaedic and Trauma Surgery. 2020. DOI: 10.1007/s00402-020-03625-x

[51] The value of magnetic resonance imaging and ultrasound in diagnosing displaced rupture of the thumb ulnar collateral ligament. Journal of Hand Surgery (European Volume). 2020. DOI: 10.1177/1753193420932496

[52] Exam Of The Hand Wrist 2Ed. Movements of the thumb.

[58] The Use of Ultrasound in the Diagnosis of Injuries of the Ulnar Collateral Ligament of the Thumb. Journal of Hand Surgery. 2000. DOI: 10.1054/jhsb.1999.0283

[60] Thumb Metacarpophalangeal Ulnar Collateral Ligament Injuries: A Biomechanical Simulation Study of Four Static Reconstructions. The Journal of Hand Surgery. 2005. DOI: 10.1016/j.jhsa.2005.05.004

[61] Clinical thumb ulnar collateral ligament injury owing to a pathological fracture through an enchondroma of the proximal phalanx. Journal of Hand Surgery (European Volume). 2025. DOI: 10.1177/17531934251315313

[62] Aaos Comprehensive Orthopaedic Review 3. Hand Trauma > VI. Thumb Metacarpophalangeal Ligament Injuries and Dislocations.

[63] Rockwood And Green S Fractures In Adults. 42: Fractures of the Distal Radius and Ulna > Open Repair of the Ulnar or Radial Collateral Ligament of the MCP Joint of the Thumb.

[66] Gamekeeper's thumb: a quantitative evaluation of acute surgical repair. Injury. 1994. DOI: 10.1016/0020-1383(94)90179-1

[67] Performance and Return to Sport After Thumb Ulnar Collateral Ligament Surgery in National Football League Players. HAND. 2018. DOI: 10.1177/1558944718760001

[80] Thumb Ulnar Collateral Ligament Repair Using Suture Anchors and Suture Tape Augmentation. Arthroscopy Techniques. 2025. DOI: 10.1016/j.eats.2025.103957

[83] Rupture of the ulnar collateral ligament of the thumb – a review. International Journal of Emergency Medicine. 2013. DOI: 10.1186/1865-1380-6-31

[90] Biomechanical Comparison of 3 Thumb Ulnar Collateral Ligament Repair Methods. The Journal of Hand Surgery. 2023. DOI: 10.1016/j.jhsa.2021.09.028

[94] Green S Operative Hand Surgery. Dislocations and Ligament Injuries of the Digits > Types of Operations > Technique of open repair of the thumb metacarpophalangeal ulnar collateral ligament..

[100] Green S Operative Hand Surgery. Dislocations and Ligament Injuries of the Digits > Chronic Ulnar Collateral Ligament Injuries (Gamekeeper’s Thumb) > Preoperative Evaluation.

[104] Green S Operative Hand Surgery. Dislocations and Ligament Injuries of the Digits > Chronic Ulnar Collateral Ligament Injuries (Gamekeeper’s Thumb) > Types of Operations.

[105] Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament Injuries: Management and Biomechanical Evaluation. Journal of the American Academy of Orthopaedic Surgeons. 2023. DOI: 10.5435/jaaos-d-22-00112

[111] Thumb metacarpophalangeal joint morphology and reconstruction of the ruptured ulnar collateral ligament. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231164260

[112] Can Physical Examination Create a Stener Lesion?. The Journal of Hand Surgery (Asian-Pacific Volume). 2017. DOI: 10.1142/s0218810417500411

[114] Ultrasonographic detection of thumb ulnar collateral ligament injuries: A cadaveric study. The Journal of Hand Surgery. 1994. DOI: 10.1016/0363-5023(94)90025-6

Creative Commons BY-NC 4.0

CC Creative Commons licence
BY Attribution — you must credit the source
NC NonCommercial — not for commercial use

Attribution-NonCommercial 4.0 International


Creative Commons Corporation ("Creative Commons") is not a law firm and does not provide legal services or legal advice. Distribution of Creative Commons public licenses does not create a lawyer-client or other relationship. Creative Commons makes its licenses and related information available on an "as-is" basis. Creative Commons gives no warranties regarding its licenses, any material licensed under their terms and conditions, or any related information. Creative Commons disclaims all liability for damages resulting from their use to the fullest extent possible.

Using Creative Commons Public Licenses

Creative Commons public licenses provide a standard set of terms and conditions that creators and other rights holders may use to share original works of authorship and other material subject to copyright and certain other rights specified in the public license below. The following considerations are for informational purposes only, are not exhaustive, and do not form part of our licenses.

Considerations for licensors: Our public licenses are intended for use by those authorized to give the public permission to use material in ways otherwise restricted by copyright and certain other rights. Our licenses are irrevocable. Licensors should read and understand the terms and conditions of the license they choose before applying it. Licensors should also secure all rights necessary before applying our licenses so that the public can reuse the material as expected. Licensors should clearly mark any material not subject to the license. This includes other CC- licensed material, or material used under an exception or limitation to copyright. More considerations for licensors: wiki.creativecommons.org/Considerations_for_licensors

Considerations for the public: By using one of our public licenses, a licensor grants the public permission to use the licensed material under specified terms and conditions. If the licensor's permission is not necessary for any reason--for example, because of any applicable exception or limitation to copyright--then that use is not regulated by the license. Our licenses grant only permissions under copyright and certain other rights that a licensor has authority to grant. Use of the licensed material may still be restricted for other reasons, including because others have copyright or other rights in the material. A licensor may make special requests, such as asking that all changes be marked or described. Although not required by our licenses, you are encouraged to respect those requests where reasonable. More considerations for the public: wiki.creativecommons.org/Considerations_for_licensees


Creative Commons Attribution-NonCommercial 4.0 International Public License

By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this Creative Commons Attribution-NonCommercial 4.0 International Public License ("Public License"). To the extent this Public License may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Licensor grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions.

Section 1 -- Definitions.

a. Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.

b. Adapter's License means the license You apply to Your Copyright and Similar Rights in Your contributions to Adapted Material in accordance with the terms and conditions of this Public License.

c. Copyright and Similar Rights means copyright and/or similar rights closely related to copyright including, without limitation, performance, broadcast, sound recording, and Sui Generis Database Rights, without regard to how the rights are labeled or categorized. For purposes of this Public License, the rights specified in Section 2(b)(1)-(2) are not Copyright and Similar Rights.

d. Effective Technological Measures means those measures that, in the absence of proper authority, may not be circumvented under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, and/or similar international agreements.

e. Exceptions and Limitations means fair use, fair dealing, and/or any other exception or limitation to Copyright and Similar Rights that applies to Your use of the Licensed Material.

f. Licensed Material means the artistic or literary work, database, or other material to which the Licensor applied this Public License.

g. Licensed Rights means the rights granted to You subject to the terms and conditions of this Public License, which are limited to all Copyright and Similar Rights that apply to Your use of the Licensed Material and that the Licensor has authority to license.

h. Licensor means the individual(s) or entity(ies) granting rights under this Public License.

i. NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.

j. Share means to provide material to the public by any means or process that requires permission under the Licensed Rights, such as reproduction, public display, public performance, distribution, dissemination, communication, or importation, and to make material available to the public including in ways that members of the public may access the material from a place and at a time individually chosen by them.

k. Sui Generis Database Rights means rights other than copyright resulting from Directive 96/9/EC of the European Parliament and of the Council of 11 March 1996 on the legal protection of databases, as amended and/or succeeded, as well as other essentially equivalent rights anywhere in the world.

l. You means the individual or entity exercising the Licensed Rights under this Public License. Your has a corresponding meaning.

Section 2 -- Scope.

a. License grant.

1. Subject to the terms and conditions of this Public License, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to:

a. reproduce and Share the Licensed Material, in whole or in part, for NonCommercial purposes only; and

b. produce, reproduce, and Share Adapted Material for NonCommercial purposes only.

2. Exceptions and Limitations. For the avoidance of doubt, where Exceptions and Limitations apply to Your use, this Public License does not apply, and You do not need to comply with its terms and conditions.

3. Term. The term of this Public License is specified in Section 6(a).

4. Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. The Licensor waives and/or agrees not to assert any right or authority to forbid You from making technical modifications necessary to exercise the Licensed Rights, including technical modifications necessary to circumvent Effective Technological Measures. For purposes of this Public License, simply making modifications authorized by this Section 2(a) (4) never produces Adapted Material.

5. Downstream recipients.

a. Offer from the Licensor -- Licensed Material. Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License.

b. No downstream restrictions. You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material.

6. No endorsement. Nothing in this Public License constitutes or may be construed as permission to assert or imply that You are, or that Your use of the Licensed Material is, connected with, or sponsored, endorsed, or granted official status by, the Licensor or others designated to receive attribution as provided in Section 3(a)(1)(A)(i).

b. Other rights.

1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.


Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.