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Chèn ép dưới mỏm cùng vai và viêm bao hoạt dịch

Subacromial impingement — causes of shoulder pain with overhead activity, diagnosis, and treatment options.

Updated Aug 2026
Một minh họa vẽ tay về gân xoay và túi hoạt dịch bị chèn ép dưới mỏm cùng vai.
Chèn ép dưới mỏm cùng vai: gân xoay cuff bị kẹp dưới mỏm cùng vai. 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 gì bạn đang cảm thấy

Bạn có thể cảm thấy một cơn đau âm ỉ sâu ở phần trên của vai. Cơn đau này thường lan xuống bên ngoài cánh tay. Nguyên nhân là do chèn ép dưới mỏm cùng vai (subacromial impingement), khiến các mô bị ép vào một khoảng hẹp phía trên khớp của bạn. Bạn cũng có thể bị viêm bao hoạt dịch, tình trạng sưng của túi chứa dịch đệm khu vực này.

Cơn đau thường trở nên nghiêm trọng hơn khi bạn nâng cánh tay lên quá đầu. Các hoạt động đơn giản như với lấy một chiếc cốc trên kệ cao hoặc cài áo vào trong quần áo có thể trở nên khó khăn. Bạn có thể gặp khó khăn khi đưa tay ra sau lưng để cài áo ngực hoặc mặc áo khoác. Những cử động này làm chèn ép các mô bị kích thích, gây ra cảm giác khó chịu nhói lên hoặc đau âm ỉ.

Các triệu chứng của bạn thường bùng phát vào ban đêm. Nhiều bệnh nhân thấy khó ngủ ở bên vai bị ảnh hưởng. Áp lực khi nằm lên vai có thể làm tăng cơn đau, khiến bạn khó duy trì giấc ngủ. Bạn cũng có thể nhận thấy cảm giác cứng khớp khi vừa thức dậy vào buổi sáng.

Tình trạng này thường phát triển chậm. Bạn có thể đã bị đau trong ít nhất sáu tháng trước khi cân nhắc phẫu thuật. Nếu nghỉ ngơi và các phương pháp điều trị chống viêm không mang lại hiệu quả, cơn đau có thể dai dẳng bất chấp những nỗ lực của bạn. Bạn có thể cảm thấy thất vọng khi các hoạt động hàng ngày trở nên khó khăn.

Chúng tôi hiểu rõ tình trạng này ảnh hưởng đến cuộc sống hàng ngày của bạn như thế nào. Mục tiêu của chúng tôi là giảm bớt áp lực này và khôi phục sự thoải mái cho bạn. Bằng cách giải quyết tình trạng chèn ép cơ học ở vai của bạn, chúng tôi hướng đến việc giúp bạn vận động tự do trở lại mà không còn đau đớn.

Những gì thực sự đang xảy ra

Vai của bạn có một khoảng trống nhỏ giữa đầu trên của xương cánh tay và vòm xương nằm phía trên. Trong khoảng không gian này, một gân và một túi chứa dịch trượt mượt mà khi bạn nâng cánh tay lên. Đây được gọi là khoảng dưới mỏm cùng vai. Khi khu vực này trở nên hẹp hoặc viêm, gân bị kẹt. Tình trạng này được gọi là chèn ép dưới mỏm cùng vai. Ma sát gây đau và sưng trong túi hoạt dịch, đây là túi đệm.

Hình dạng của vòm xương đóng một vai trò lớn. Một số người có hình dạng xương cong hoặc móc, làm hẹp khoảng không gian này một cách tự nhiên. Điều này làm tăng áp lực lên gân mỗi khi bạn di chuyển cánh tay. Dây chằng cùng vai - mỏm cùng vai, một dải mô chạy ngang phía trên, cũng có thể co lại và đè xuống gân. Sự chèn ép cơ học này là nguyên nhân gây ra cơn đau nhói khi bạn với tay lên cao hoặc nằm nghiêng sang bên đó.

Chúng tôi thường thấy vấn đề này trở nên tồi tệ hơn nếu gân đã bị kích thích hoặc tổn thương. Viêm mạn tính làm cho các mô cứng hơn và kém linh hoạt hơn. Điều này làm giảm phạm vi chuyển động của bạn, đặc biệt là khi nâng cánh tay ra bên cạnh hoặc xoay vào trong. Bạn có thể cảm thấy yếu hoặc trải qua cơn đau trong các cử động mạnh. Tuy nhiên, không phải ai có những thay đổi này cũng cần phẫu thuật. Nhiều bệnh nhân tìm thấy sự giảm nhẹ thông qua chăm sóc không phẫu thuật trước tiên.

Nếu cần phẫu thuật, mục tiêu là tạo thêm không gian trong khoảng trống chật hẹp đó. Điều này có thể liên quan đến việc làm mịn vòm xương hoặc loại bỏ một phần dây chằng. Thủ thuật này được gọi là giải phóng chèn ép dưới mỏm cùng vai. Nó nhằm mục đích ngăn chặn sự chèn ép để gân có thể lành lại và di chuyển tự do trở lại. Đối với một số bệnh nhân, điều này cung cấp giảm đau đáng kể và khôi phục chức năng. Đối với những người khác, tổn thương gân cơ bản có thể yêu cầu một cách tiếp cận khác, chẳng hạn như sửa chữa vết rách. Bác sĩ phẫu thuật của bạn sẽ giúp bạn hiểu tùy chọn nào phù hợp với giải phẫu và triệu chứng cụ thể của bạn.

Những gì chúng tôi có thể làm về vấn đề này

Trang này phản ánh cách Bác sĩ Kieran Hirpara, một bác sĩ phẫu thuật chi trên tại Bệnh viện Tư nhân Mater Rockhampton, tiếp cận vấn đề này trong phòng khám của chúng tôi. Chúng tôi hướng dẫn bạn qua một lộ trình rõ ràng từ tự chăm sóc đến phẫu thuật, chỉ khi cần thiết. Bệnh nhân đến phòng khám của chúng tôi qua giới thiệu của bác sĩ đa khoa hoặc chuyên viên vật lý trị liệu. Một đánh giá tại phòng khám — bao gồm khai thác bệnh sử, khám lâm sàng và chụp hình ảnh khi cần thiết — giúp thiết lập chẩn đoán. Đối với các vấn đề thoái hóa hoặc mãn tính, chúng tôi thường thử điều trị không phẫu thuật trước. Chúng tôi xem xét phẫu thuật khi phương pháp đó không mang lại cải thiện đủ mức. Đối với các vấn đề cấu trúc hoặc cấp tính, phẫu thuật có thể được khuyến nghị ngay lập tức.

Quản lý bảo tồn là phương pháp chính ban đầu để điều trị hội chứng chèn ép dưới mỏm cùng vai. Chúng tôi bắt đầu bằng việc thay đổi hoạt động để tránh các cử động gây đau. Vật lý trị liệu nhằm mục đích tăng cường cơ vai và cải thiện tầm vận động của bạn. Bạn nên dành ít nhất 6 tuần cho phương pháp này để thấy kết quả. Nếu đau vẫn tiếp diễn, chúng tôi có thể đề xuất tiêm cortisone vào bao hoạt dịch (túi chứa dịch dưới xương vai). Điều này làm giảm viêm và đau. Hiệu quả chỉ mang tính tạm thời nhưng có thể giúp bạn tham gia vật lý trị liệu hiệu quả hơn. Một số bệnh nhân cũng được hưởng lợi từ các tiêm axit hyaluronic hoặc PRP (huyết tương giàu tiểu cầu), mặc dù bằng chứng về các phương pháp này còn khác nhau. Chúng tôi theo dõi tiến triển của bạn một cách chặt chẽ để đảm bảo bạn đang đi đúng hướng.

Phẫu thuật được dành cho các trường hợp mà các biện pháp bảo tồn thất bại. Giải áp dưới mỏm cùng vai nội soi là một phương pháp điều trị hợp lệ, giúp giảm đau và cải thiện chất lượng cuộc sống cho những bệnh nhân được lựa chọn theo hướng dẫn quốc gia. Chúng tôi xem xét lựa chọn này nếu bạn đã bị đau ít nhất 6 tháng, có kết quả kiểm tra Hawkins dương tính liên tục (một dấu hiệu khám lâm sàng cụ thể), và có bằng chứng hình ảnh học về chèn ép cơ học. Thủ thuật này loại bỏ gai xương hoặc mô viêm để tạo thêm không gian cho các gân của bạn. Đây là một lựa chọn thay thế cho phẫu thuật mở trong các trường hợp tiến triển. Chúng tôi cũng sử dụng phong bế bao hoạt dịch dưới mỏm cùng vai để giảm đau sau phẫu thuật hiệu quả, giúp giảm nhu cầu sử dụng thuốc giảm đau mạnh. Nếu bạn có rách gân xoay cuff, sửa chữa phẫu thuật thường mang lại kết quả tốt hơn đáng kể so với chỉ giải áp. Chúng tôi trình bày các lựa chọn này như một quyết định chung, đảm bảo bạn hiểu rõ lợi ích và hạn chế của từng bước.

Những điều cần biết

Ở nhiều người, đau vai do chèn ép và viêm bao hoạt dịch sẽ thuyên giảm với điều trị không phẫu thuật. Liệu pháp tập luyện đặc hiệu có hiệu quả và làm giảm nhu cầu phẫu thuật. Những kết quả này được duy trì sau 10 năm. Nếu cơn đau của bạn vẫn tiếp diễn, quản lý bảo tồn vẫn là phương pháp chính ban đầu, với phẫu thuật được dành riêng cho các trường hợp không cải thiện.

Phẫu thuật thường được xem xét nếu bạn đã bị đau ít nhất 6 tháng, có dấu hiệu chèn ép cơ học khi khám, và không đáp ứng với các biện pháp khác. Khi đáp ứng các tiêu chí cụ thể này, kết quả thường tích cực. Bạn có thể mong đợi sự cải thiện về chức năng vai và chất lượng cuộc sống. Lợi ích này vẫn đúng ngay cả khi bạn đang đối mặt với trầm cảm nền hoặc các triệu chứng trầm cảm.

Nếu bạn trải qua phẫu thuật giải phóng chèn ép dưới mỏm vai nội soi, quá trình hồi phục của bạn sẽ diễn ra theo một lộ trình dự đoán được. Hơn 90% bệnh nhân có thể quay lại lái xe trong vòng 4 tuần và trở lại làm việc trong vòng 6 tuần theo các nghiên cứu được công bố; tuy nhiên, lời khuyên tiêu chuẩn của chúng tôi vẫn là không lái xe trong sáu tuần sau bất kỳ phẫu thuật vai nào, cho đến khi được bác sĩ cho phép tại buổi tái khám. Nếu thủ thuật của bạn liên quan đến việc loại bỏ các lắng đọng canxi, bạn có thể cần nhiều thời gian hơn để quay lại hoạt động không hạn chế mà không đau. Việc phục hồi chức năng vai chủ quan mất gần 3 tháng trung bình nếu các lắng đọng canxi mạn tính được loại bỏ mà không có mổ mỏm vai.

Điều quan trọng là phải biết rằng phẫu thuật này không phải lúc nào cũng cần thiết hoặc có lợi cho mọi vấn đề về vai. Không có bằng chứng mạnh mẽ nào ủng hộ phẫu thuật giải phóng chèn ép dưới mỏm vai chỉ riêng cho viêm gân xoay cuff. Hơn nữa, nếu bạn cần phẫu thuật sửa chữa xoay cuff, phẫu thuật giải phóng chèn ép dưới mỏm vai chính thức không dẫn đến kết quả lâm sàng được cải thiện cho đến 2 năm sau khi sửa chữa. Trong một số trường hợp, kết quả đáng kể cao hơn khi phẫu thuật sửa chữa xoay cuff được thực hiện mà không có giải phóng chèn ép.

Bác sĩ phẫu thuật của bạn sẽ giúp bạn quyết định xem phẫu thuật có phù hợp với bạn hay không dựa trên việc lựa chọn bệnh nhân cẩn thận. Nếu bạn không cần phẫu thuật, liệu pháp tập luyện cung cấp một con đường hợp lệ để giảm đau. Nếu bạn tiến hành phẫu thuật, mục tiêu là giảm đau và khôi phục chức năng. Tiên lượng của bạn phụ thuộc vào mức độ phù hợp của tình trạng của bạn với các tiêu chí cho thủ thuật cụ thể này.

Khi nào nên gặp bác sĩ

Hãy yêu cầu đánh giá từ bác sĩ chuyên khoa nếu bạn bị đau vai không cải thiện sau sáu tháng nghỉ ngơi và các biện pháp điều trị không phẫu thuật khác. Bạn cũng nên tìm kiếm sự giúp đỡ nếu gặp phải tình trạng yếu cơ, mất ổn định khớp, hoặc nếu các triệu chứng cản trở giấc ngủ hoặc công việc của bạn. Phẫu thuật thường được xem xét khi có bằng chứng rõ ràng về tình trạng chèn ép cơ học. Bác sĩ phẫu thuật sẽ sử dụng khám lâm sàng để kiểm tra các dấu hiệu cụ thể, chẳng hạn như nghiệm pháp Hawkins dương tính, nhằm xác định nguyên nhân. Điều này giúp đảm bảo bạn được lựa chọn điều trị phù hợp. Đánh giá sớm có thể làm rõ liệu việc tiếp tục chăm sóc bảo tồn hay một thủ thuật như giải phóng chèn ép dưới mỏm cùng vai có phù hợp với bạn hay không.


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

  • Management of subacromial impingement syndrome includes physical therapy, injections, and surgery for some patients [2].
  • There remains a need for high-quality studies of the pathology, etiology, and management of subacromial impingement syndrome [2].
  • Current randomized, controlled trial evidence shows no difference in outcomes of shoulder function or pain between surgical and conservative treatment for subacromial impingement syndrome [3].
  • Ultrasound guidance is not superior in the subacromial bursa and glenohumeral joint injections in pain or function [4].
  • Subacromial pain syndrome (SAPS) should preferably be treated non-operatively [6].
  • Subacromial injection with corticosteroids is indicated for persistent or recurrent symptoms of SAPS [6].
  • Arthroscopic subacromial decompression provided no benefit over diagnostic arthroscopy at 24 months in patients with shoulder impingement syndrome [10].
  • Arthroscopic subacromial decompression provided no benefit over diagnostic arthroscopy or exercise therapy at 5 years for patients with shoulder impingement syndrome [11].
  • Arthroscopic subacromial decompression provided no benefit over diagnostic arthroscopy or exercise therapy on return to work in patients with shoulder impingement syndrome [16].
  • Arthroscopic subacromial decompression yields good long-term results in the treatment of subacromial impingement for small full-thickness tears [13].
  • Adding a large dose of shoulder strengthening to current nonoperative care for patients with subacromial impingement did not result in superior shoulder-specific patient-reported outcomes [14].
  • For patients with a long-term disease course, operative treatments may be considered [15].
  • Standard arthroscopic subacromial decompression (ASD) surgery is preferred over arthroscopic bursectomy and the open surgical technique for subacromial decompression [15].
  • Preserving the subacromial bursa during rotator cuff surgery may lead to better rotator cuff healing when secondary pain is manageable [22].
  • Arthroscopic subacromial decompression is a valid treatment, reducing pain and improving quality of life for patients selected for surgery according to the Danish national guidelines [26].

Anatomy & Pathophysiology

  • Ultrasound guidance is not superior to landmark-based techniques for subacromial bursa injections regarding pain or function outcomes [4].
  • Ultrasound guidance is not superior to landmark-based techniques for glenohumeral joint injections regarding pain or function outcomes [4].
  • Ultrasound guidance is superior to landmark-based techniques for bicipital groove injections [4].
  • A comprehensive classification of individualized impingements around the anterior aspect of the shoulder has been proposed to address conflicting etiologic theories and improve understanding of diagnosis and treatment [5].
  • Imaging abnormalities of the acromioclavicular joint are common in asymptomatic shoulders [7].
  • Imaging abnormalities of the subacromial space are common in asymptomatic shoulders [7].
  • There is no relationship between acromiohumeral distance (AHD) and pain in adults with subacromial pain syndrome [18].
  • There is no between-group difference in AHD in neutral shoulder position between symptomatic and asymptomatic groups [18].
  • There is no between-group difference in AHD at 45° shoulder abduction between symptomatic and asymptomatic groups [18].
  • There is no between-group difference in AHD at 60° shoulder abduction between symptomatic and asymptomatic groups [18].
  • Subacromial notching rates are low following reverse shoulder arthroplasty using a 135° inlay humeral component and a lateralized glenoid [19].
  • Subacromial notching is not associated with functional outcomes at short-term follow-up [19].
  • Subacromial notching is not associated with range of motion at short-term follow-up [19].
  • Subacromial balloon spacer (SBS) implantation in cadaveric models of irreparable rotator cuff tears results in significant improvements in humeral head position at 0° shoulder abduction [31].
  • Subacromial balloon spacer (SBS) implantation in cadaveric models of irreparable rotator cuff tears results in significant improvements in humeral head position at 30° shoulder abduction [31].
  • Subacromial balloon spacer (SBS) implantation in cadaveric models of irreparable rotator cuff tears results in significant improvements in humeral head position at 60° shoulder abduction [31].
  • Subacromial balloon spacers resist superior humeral head migration in cadaveric studies [45].
  • Subacromial balloon spacers reduce subacromial pressure in cadaveric studies [45].
  • Conservation of sufficient subacromial space may have a significant impact on the passive and active function of reverse shoulder arthroplasty [33].
  • Conservation of sufficient coracohumeral space may have a significant impact on the passive and active function of reverse shoulder arthroplasty [33].
  • Conservation of scapular posture may have a significant impact on the passive and active function of reverse shoulder arthroplasty [33].
  • Understanding moment arms is essential to optimize active force generation in reverse shoulder arthroplasty [33].
  • Understanding muscle tensioning is essential to optimize reverse shoulder arthroplasty performance [33].
  • Superior capsular reconstruction (SCR) improves glenohumeral superior translation compared with rotator cuff tear at time zero [37].
  • Superior capsular reconstruction (SCR) improves subacromial contact pressure compared with rotator cuff tear at time zero [37].
  • The improvement in glenohumeral superior translation and subacromial contact pressure with SCR is independent of graft type [37].
  • Addressing aberrant movement patterns and facilitating balanced activation of all shoulder muscles may be an appropriate treatment direction for subacromial pain syndrome [34].
  • Scapular-focused interventions result in a between-group difference in shoulder abduction range of motion in the short term only [39].
  • Patients who are candidates for subacromial decompression have more pronounced range of motion deficits compared to non-candidates [40].
  • Patients who are candidates for subacromial decompression do not differ in self-reported shoulder function compared to non-candidates [40].
  • Patients who are candidates for subacromial decompression do not differ in strength compared to non-candidates [40].
  • Patients who are candidates for subacromial decompression do not differ in pain compared to non-candidates [40].
  • A decrease in abduction range of motion is associated with being considered a candidate for subacromial decompression [40].
  • A decrease in internal rotation range of motion is associated with being considered a candidate for subacromial decompression [40].
  • Increased pain during maximal abduction strength effort is associated with being considered a candidate for subacromial decompression [40].
  • The Disabilities of the Arm, Shoulder and Hand (DASH) Questionnaire may not be adequate to assess individuals with subacromial pain syndrome when pain occurs above 120 degrees of arm elevation [42].
  • Lifestyle factors including sleep behaviors and shoulder usage patterns are potential associations with subacromial impingement syndrome [48].
  • Improving sleep behaviors and optimizing shoulder usage patterns are effective measures to prevent subacromial impingement syndrome [48].

Classification

  • Patients presenting with signs and symptoms of subacromial pain syndrome have a high prevalence of conflicting and concomitant diagnoses [1].
  • The article proposes a comprehensive classification of all individualized impingements occurring around the anterior aspect of the shoulder, including newly described entities [5].

Clinical Presentation

  • Imaging abnormalities of the acromioclavicular joint and subacromial space are common in asymptomatic shoulders [7].
  • Synovitis in the subacromial space was milder and not associated with any clinical parameters [8].
  • Women aged between 30 and 60 years with subacromial pain syndrome and a calcific deposit of >1.5 cm in length have the highest chance of suffering from symptomatic calcific tendinopathy of the rotator cuff [20].
  • Night pain is a common complaint of patients presenting with impingement of the shoulder but cannot be used in isolation as a diagnostic predictor for the presence of a rotator cuff tear [32].
  • Examination of the cervical spine in patients with subacromial shoulder pain is variable in randomized controlled trials [24].

Investigations

  • Due to low certainty of evidence and significant variation among study populations, further research is needed to clarify prevalence estimates of shoulder abnormalities [7].
  • Ultrasound guidance is not superior to non-guided injection for pain or function outcomes in the subacromial bursa and glenohumeral joint [4].
  • Ultrasound guidance is superior to non-guided injection in the bicipital groove [4].
  • Synovitis in the subacromial space was found to be mild and not associated with any clinical parameters in patients with rotator cuff tears [8].
  • Diagnostic and therapeutic practices regarding internal impingement of the shoulder differ between surgeons, with French surgeons relying more on CT-arthrography and intra-articular injections while international surgeons favor MRI and physical therapy [41].
  • The acromiohumeral distance is significantly smaller on MRI compared to AP radiographs in shoulders with an intact rotator cuff [47].
  • The acromiohumeral distance on MRI should not be used as a decision criterion to assess glenohumeral centering or subacromial space width in shoulders with an intact rotator cuff [47].
  • Machine learning-based ultrasomics may be helpful in the preliminary screening of shoulder pain for subacromial impingement syndrome stages [49].
  • The subacromial space width is smaller in nearly all rotator cuff pathologies, becomes even smaller as condition severity increases, and is smaller in the case of a complete cuff tear [50].

Treatment

  • Ultrasound guidance is not superior to non-guided techniques in the subacromial bursa and glenohumeral joint injections regarding pain or function [4].
  • Subacromial pain syndrome should preferably be treated non-operatively, with subacromial injection with corticosteroids indicated for persistent or recurrent symptoms [6].
  • Most management regimes for subacromial impingement employ a minimum period of 12 weeks of conservative management incorporating physiotherapy and at least 2 subacromial steroid injections [9].
  • Arthroscopic subacromial decompression yields good long-term results in patients with small full-thickness tears [13].
  • Adding a large dose of shoulder strengthening to current nonoperative care for subacromial impingement did not result in superior shoulder-specific patient-reported outcomes [14].
  • For patients with a long-term disease course, operative treatments may be considered, with standard arthroscopic subacromial decompression (ASD) surgery preferred over arthroscopic bursectomy and open surgical technique [15].
  • Arthroscopic subacromial decompression is a valid treatment that reduces pain and improves quality of life for patients selected for surgery according to Danish national guidelines [26].
  • Five randomized trials found that formal subacromial decompression does not result in improved clinical outcomes up to 2 years after rotator cuff repair [27].
  • There is no evidence from available randomized controlled trials for differences in outcome in pain and shoulder function between conservatively and surgically treated patients with subacromial impingement syndrome [28].
  • The evidence on the effectiveness of surgical or conservative treatment of shoulder impingement is limited based on a review of seven randomized controlled trials [35].
  • There is little reproducible evidence to support the efficacy of subacromial corticosteroid injection in managing rotator cuff disease [38].

Complications

  • Subacromial osteolysis has a relatively high and variable incidence following hook plate fixation for acromioclavicular dislocation [17].
  • The primary factor influencing the reported incidence of subacromial osteolysis is the radiological assessment method [17].
  • Rates of subacromial notching are low following reverse shoulder arthroplasty with a 135° inlay humeral component and a lateralized glenoid [19].
  • When subacromial notching occurs, it is not associated with functional outcomes or range of motion at short-term follow-up [19].

Recovery

  • Variation exists in the management regimes offered to patients with subacromial impingement, but most employ a minimum period of 12 weeks of conservative management incorporating physiotherapy and at least 2 subacromial steroid injections [9].
  • Arthroscopic subacromial decompression (ASD) in the treatment of subacromial impingement yields good long-term results [13].
  • For patients who have a long-term disease course, operative treatments may be considered, with standard ASD surgery preferred over arthroscopic bursectomy and the open surgical technique for subacromial decompression [15].
  • Subacromial osteolysis has a relatively high and variable incidence, and the primary factor influencing the reported incidence is the radiological assessment method [17].
  • There was no between group difference in acromiohumeral distance (AHD) in neutral shoulder position, shoulder abduction at 45° or 60° [18].
  • When subacromial notching occurs following reverse shoulder arthroplasty with a 135° inlay humeral component and a lateralized glenoid, it is not associated with functional outcomes or range of motion at short-term follow-up [19].
  • More than half of patients diagnosed with subacromial pain syndrome in specialist care settings do not adhere to recommendations regarding duration of exercise-therapy, but this is not related to symptom improvement [23].
  • Major improvements in pain/function were seen at mid- to long-term after isolated arthroscopic subacromial decompression and combined decompression/rotator cuff repair [25].
  • Adding a large dose of shoulder strengthening exercises to nonoperative care for 16 weeks did not significantly improve long-term outcomes in terms of shoulder disability, health-related quality of life, sick leave, or surgery rates at 1 year [29].
  • There was no evidence of progression of intrinsic rotator cuff pathologic conditions at a mean follow-up of 4.5 years for partial-thickness rotator cuff tears treated with acromioplasty without repair [30].

Key Evidence

  • [L3] Patients presenting with signs and symptoms of subacromial pain syndrome have a high prevalence of conflicting and concomitant diagnoses. [1] (10.1177/23259671251332942)
  • [L5] Management of subacromial impingement syndrome includes physical therapy, injections, and surgery for some patients, but there remains a need for high-quality studies of the pathology, etiology, and management of the condition. [2] (10.5435/00124635-201111000-00006)
  • [L1] Current randomized, controlled trial evidence shows no difference in outcomes of shoulder function or pain between surgical and conservative treatment for subacromial impingement syndrome. [3] (10.2106/jbjs.9202.ebo579)
  • [L1] Ultrasound guidance is not superior in the subacromial bursa and glenohumeral joint injections in pain or function. [4] (10.1016/j.arthro.2021.12.013)
  • [L4] The article proposes a comprehensive classification of all individualized impingements occurring around the anterior aspect of the shoulder, including newly described entities, to address conflicting theories and improve understanding of their etiologic factors, diagnosis, and treatment. [5] (10.1007/s00264-017-3515-1)
  • [Paper] SAPS should preferably be treated non-operatively, with subacromial injection with corticosteroids indicated for persistent or recurrent symptoms. [6] (10.3109/17453674.2014.920991)
  • [L2] Due to the low certainty of evidence and significant variation among study populations, further research is needed to clarify these prevalence estimates and to guide evidence-based management of shoulder abnormalities. [7] (10.1186/s13018-024-05378-4)
  • [L4] Synovitis in the subacromial space was milder and not associated with any clinical parameters. [8] (10.1177/23259671231207818)
  • [L4] Variation exists in the management regimes offered to patients with subacromial impingement, but most employ a minimum period of 12 weeks of conservative management incorporating physiotherapy and at least 2 subacromial steroid injections. [9] (10.1177/1758573215571010)
  • [L1] In this controlled trial involving patients with a shoulder impingement syndrome, arthroscopic subacromial decompression provided no benefit over diagnostic arthroscopy at 24 months. [10] (10.1136/bmj.k2860)
  • [L1] Arthroscopic subacromial decompression provided no benefit over diagnostic arthroscopy or exercise therapy at 5 years for patients with shoulder impingement syndrome. [11] (10.1136/bjsports-2020-102216)
  • [L3] ASD in the treatment of subacromial impingement yields good long-term results. [13] (10.1016/j.jse.2007.06.020)
  • [L1] Adding a large dose of shoulder strengthening to current nonoperative care for patients with subacromial impingement did not result in superior shoulder-specific patient-reported outcomes. [14] (10.1177/03635465211016008)
  • [L1] For patients who have a long-term disease course, operative treatments may be considered, with standard ASD surgery preferred over arthroscopic bursectomy and the open surgical technique for subacromial decompression. [15] (10.1097/md.0000000000000510)
  • [L1] Arthroscopic subacromial decompression provided no benefit over diagnostic arthroscopy or exercise therapy on return to work in patients with shoulder impingement syndrome. [16] (10.1186/s12891-021-04768-7)
  • [L1] Subacromial osteolysis has a relatively high and variable incidence, and the primary factor influencing the reported incidence is the radiological assessment method. [17] (10.1016/j.jse.2024.03.018)
  • [L1] There was no between group difference in acromiohumeral distance (AHD) in neutral shoulder position, shoulder abduction at 45° or 60°. [18] (10.1038/s41598-020-76704-z)
  • [L3] When subacromial notching occurs, it is not associated with functional outcomes or range of motion at short-term follow-up. [19] (10.1016/j.jseint.2024.01.009)
  • [L3] This study demonstrates that women aged between 30 and 60 years with subacromial pain syndrome and a calcific deposit of >1.5 cm in length have the highest chance of suffering from symptomatic calcific tendinopathy of the rotator cuff. [20] (10.1016/j.jse.2015.02.024)
  • [L5] Preserving the subacromial bursa during rotator cuff surgery may lead to better rotator cuff healing when secondary pain is manageable. [22] (10.1530/eor-2024-0183)
  • [L3] More than half of patients diagnosed with subacromial pain syndrome in specialist care settings do not adhere to recommendations regarding duration of exercise-therapy, but this is not related to symptom improvement. [23] (10.1016/j.msksp.2021.102322)
  • [L1] Examination of the cervical spine in patients with subacromial shoulder pain is variable in randomized controlled trials. [24] (10.1177/1758573218798023)
  • [L3] Major improvements in pain/function were seen at mid- to long-term after isolated arthroscopic subacromial decompression and combined decompression/rotator cuff repair. [25] (10.1016/j.jor.2018.03.004)
  • [L4] Arthroscopic subacromial decompression is a valid treatment, reducing pain and improving quality of life for patients selected for surgery according to the Danish national guidelines. [26] (10.1016/j.jse.2017.03.028)
  • [L1] Five randomized trials found that formal subacromial decompression does not result in improved clinical outcomes up to 2 years after rotator cuff repair. [27] (10.1016/j.arthro.2012.06.003)
  • [L1] According to the best-evidence synthesis, there is no evidence from the available RCTs for differences in outcome in pain and shoulder function between conservatively and surgically treated patients with SIS. [28] (10.1016/j.jse.2009.01.010)
  • [L1] Adding a large dose of shoulder strengthening exercises to nonoperative care for 16 weeks did not significantly improve long-term outcomes in terms of shoulder disability, health-related quality of life, sick leave, or surgery rates at 1 year. [29] (10.1177/23259671251374314)
  • [L4] There was no evidence of progression of intrinsic rotator cuff pathologic conditions at a mean follow-up of 4.5 years. [30] (10.1177/03635465020300021801)
  • [L4] SBS implantation in cadaveric models of irreparable rotator cuff tears results in significant improvements in humeral head position at 0, 30, and 60 of shoulder abduction. [31] (10.1177/03635465221150652)
  • [L3] Night pain is a common complaint of patients presenting with impingement of the shoulder but cannot be used in isolation as a diagnostic predictor for the presence of a rotator cuff tear. [32] (10.1111/j.1758-5740.2011.00133.x)
  • [L5] Conservation of sufficient subacromial and coracohumeral space and scapular posture may have a significant impact on the passive and active function of reverse shoulder arthroplasty, while understanding moment arms and muscle tensioning is essential to optimize active force generation and RSA performance. [33] (10.3390/jcm12041616)
  • [L1] Addressing aberrant movement patterns and facilitating balanced activation of all shoulder muscles may be a more appropriate treatment direction for the future. [34] (10.1177/1758573216660038)
  • [L1] Based on the review of seven RCTs, the evidence on effectiveness of surgical or conservative treatment of shoulder impingement was found to be limited. [35] (10.3109/09638288.2014.907364)
  • [L1] Independent of graft type, biomechanical studies suggest that SCR improves glenohumeral superior translation and subacromial contact pressure in comparison with RTC tear at time zero. [37] (10.1016/j.arthro.2023.08.025)
  • [L1] This systematic review of the available literature indicates that there is little reproducible evidence to support the efficacy of subacromial corticosteroid injection in managing rotator cuff disease. [38] (10.5435/00124635-200701000-00002)
  • [L1] A between-group difference in shoulder abduction ROM in the short term only was found. [39] (10.1080/09593985.2018.1423656)
  • [L4] A decrease in abduction and internal rotation range of motion, and increased pain during maximal abduction strength effort are associated with being considered a candidate for subacromial decompression, while self-reported shoulder function, pain during the last week, and rotator cuff strength are not. [40] (10.1007/s00167-018-4894-6)
  • [L4] Diagnostic and therapeutic practices regarding internal impingement of the shoulder differ between surgeons in France and in other countries, with French surgeons relying more on CT-arthrography and intra-articular injections, while international surgeons favor MRI and physical therapy. [41] (10.1016/j.otsr.2019.09.007)
  • [L4] The DASH may not be adequate to assess those with shoulder pain above 120 degrees of arm elevation. [42] (10.1093/ptj/pzab065)
  • [L1] In cadaveric studies, subacromial balloon spacers resist superior humeral head migration and reduce subacromial pressure. [45] (10.1016/j.asmr.2020.06.011)
  • [L4] The acromiohumeral distance is significantly smaller in the MRI in comparison to AP radiographs in shoulders with an intact rotator cuff and should not be used as a decision criterion on MRI to assess glenohumeral centering or subacromial space width. [47] (10.1007/s00167-020-06090-6)
  • [L1] This evidence supports the development of strategies aimed at improving sleep behaviors and optimizing shoulder usage patterns as effective measures to prevent SIS. [48] (10.1186/s12891-024-07345-w)
  • [L4] This noninvasive and low-cost approach may be helpful in the preliminary screening of shoulder pain. [49] (10.1002/jum.15914)
  • [L4] The subacromial space width is smaller in nearly all rotator cuff pathologies, but becomes even smaller as the severity of the condition increases and is smaller in the case of a complete cuff tear. [50] (10.1016/j.ultras.2003.11.015)

References

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[2] Subacromial Impingement Syndrome. American Academy of Orthopaedic Surgeon. 2011. DOI: 10.5435/00124635-201111000-00006

[3] Current Evidence Fails to Show Differences in Effectiveness Between Conservative and Surgical Treatment of Subacromial Impingement Syndrome. The Journal of Bone & Joint Surgery. 2010. DOI: 10.2106/jbjs.9202.ebo579

[4] Ultrasound Guidance Is Not Superior in Subacromial Bursa and Intraarticular Injections but Superior in Bicipital Groove: A Meta-analysis of Randomized Controlled Trials. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2022. DOI: 10.1016/j.arthro.2021.12.013

[5] Redefining anterior shoulder impingement: a literature review. International Orthopaedics. 2017. DOI: 10.1007/s00264-017-3515-1

[6] Guideline for diagnosis and treatment of subacromial pain syndrome. Acta Orthopaedica. 2014. DOI: 10.3109/17453674.2014.920991

[7] Imaging abnormalities of the acromioclavicular joint and subacromial space are common in asymptomatic shoulders: a systematic review. Journal of Orthopaedic Surgery and Research. 2025. DOI: 10.1186/s13018-024-05378-4

[8] Clinical Implication of Glenohumeral and Subacromial Synovitis in Rotator Cuff Tears. Orthopaedic Journal of Sports Medicine. 2023. DOI: 10.1177/23259671231207818

[9] Current UK practices in the management of subacromial impingement. Shoulder & Elbow. 2015. DOI: 10.1177/1758573215571010

[10] Subacromial decompression versus diagnostic arthroscopy for shoulder impingement: randomised, placebo surgery controlled clinical trial. BMJ. 2018. DOI: 10.1136/bmj.k2860

[11] Subacromial decompression versus diagnostic arthroscopy for shoulder impingement: a 5-year follow-up of a randomised, placebo surgery controlled clinical trial. British Journal of Sports Medicine. 2020. DOI: 10.1136/bjsports-2020-102216

[13] Small full-thickness tears do well ten to thirteen years after arthroscopic subacromial decompression. Journal of Shoulder and Elbow Surgery. 2008. DOI: 10.1016/j.jse.2007.06.020

[14] Effectiveness of Adding a Large Dose of Shoulder Strengthening to Current Nonoperative Care for Subacromial Impingement: A Pragmatic, Double-Blind Randomized Controlled Trial (SExSI Trial). The American Journal of Sports Medicine. 2021. DOI: 10.1177/03635465211016008

[15] Treatments for Shoulder Impingement Syndrome. Medicine. 2015. DOI: 10.1097/md.0000000000000510

[16] Return to work after subacromial decompression, diagnostic arthroscopy, or exercise therapy for shoulder impingement: a randomised, placebo-surgery controlled FIMPACT clinical trial with five-year follow-up. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04768-7

[17] Subacromial osteolysis following hook plate fixation for acromioclavicular dislocation: a systematic review and meta-analysis. Journal of Shoulder and Elbow Surgery. 2024. DOI: 10.1016/j.jse.2024.03.018

[18] No relationship between the acromiohumeral distance and pain in adults with subacromial pain syndrome: a systematic review and meta-analysis. Scientific Reports. 2020. DOI: 10.1038/s41598-020-76704-z

[19] Rates of subacromial notching are low following reverse shoulder arthroplasty with a 135° inlay humeral component and a lateralized glenoid. JSES International. 2024. DOI: 10.1016/j.jseint.2024.01.009

[20] Prevalence of calcific deposits within the rotator cuff tendons in adults with and without subacromial pain syndrome: clinical and radiologic analysis of 1219 patients. Journal of Shoulder and Elbow Surgery. 2015. DOI: 10.1016/j.jse.2015.02.024

[22] Removal or retention: evolving views on possible roles of the subacromial bursa in rotator cuff disease. EFORT Open Reviews. 2025. DOI: 10.1530/eor-2024-0183

[23] Less than half of patients in secondary care adheres to clinical guidelines for subacromial pain syndrome and have acceptable symptoms after treatment: A Danish nationwide cohort study of 3306 patients. Musculoskeletal Science and Practice. 2021. DOI: 10.1016/j.msksp.2021.102322

[24] Screening of the cervical spine in subacromial shoulder pain: A systematic review. Shoulder & Elbow. 2018. DOI: 10.1177/1758573218798023

[25] Long-term results after surgical treatment of subacromial pain syndrome with or without rotator cuff tear. Journal of Orthopaedics. 2018. DOI: 10.1016/j.jor.2018.03.004

[26] Acromioplasty in patients selected for operation by national guidelines. Journal of Shoulder and Elbow Surgery. 2017. DOI: 10.1016/j.jse.2017.03.028

[27] The Changing Role of Acromioplasty. Arthroscopy. 2012. DOI: 10.1016/j.arthro.2012.06.003

[28] Conservative or surgical treatment for subacromial impingement syndrome? A systematic review. Journal of Shoulder and Elbow Surgery. 2009. DOI: 10.1016/j.jse.2009.01.010

[29] The Effect of Adding a Large Dose of Shoulder Strengthening to Nonoperative Care for Subacromial Impingement on Shoulder Disability, Quality of Life, Sick Days, and Surgery Rates: 1-Year Results From a Pragmatic, Double-Blind Randomized Controlled Trial (SExSI). Orthopaedic Journal of Sports Medicine. 2025. DOI: 10.1177/23259671251374314

[30] The Partial-Thickness Rotator Cuff Tear: Is Acromioplasty without Repair Sufficient?. The American Journal of Sports Medicine. 2002. DOI: 10.1177/03635465020300021801

[31] Subacromial Balloon Spacer Implantation for Massive Irreparable Rotator Cuff Tears Is Associated With Restoration of the Acromiohumeral Interval and Glenohumeral Center of Pressure: A Systematic Review and Meta-Analysis of Controlled Laboratory Studies. The American Journal of Sports Medicine. 2023. DOI: 10.1177/03635465221150652

[32] Night Pain is not a useful Diagnostic Indicator of Cuff Tear in Patients with Symptoms of Subacromial Impingement. Shoulder & Elbow. 2011. DOI: 10.1111/j.1758-5740.2011.00133.x

[33] Challenges for Optimization of Reverse Shoulder Arthroplasty Part II: Subacromial Space, Scapular Posture, Moment Arms and Muscle Tensioning. Journal of Clinical Medicine. 2023. DOI: 10.3390/jcm12041616

[34] Electromyographic activity of the shoulder muscles during rehabilitation exercises in subjects with and without subacromial pain syndrome: a systematic review. Shoulder & Elbow. 2016. DOI: 10.1177/1758573216660038

[35] Conservative treatment or surgery for shoulder impingement: systematic review and meta-analysis. Disability and Rehabilitation. 2014. DOI: 10.3109/09638288.2014.907364

[37] Glenohumeral Superior Translation and Subacromial Contract Pressure Are Both Improved With Superior Capsular Reconstruction: A Systematic Review and Meta‐analysis of Biomechanical Investigations. Arthroscopy. 2023. DOI: 10.1016/j.arthro.2023.08.025

[38] The Efficacy of Subacromial Corticosteroid Injection in the Treatment of Rotator Cuff Disease: A Systematic Review. Journal of the American Academy of Orthopaedic Surgeons. 2007. DOI: 10.5435/00124635-200701000-00002

[39] Scapular focused interventions to improve shoulder pain and function in adults with subacromial pain: A systematic review and meta-analysis. Physiotherapy Theory and Practice. 2018. DOI: 10.1080/09593985.2018.1423656

[40] Patients who are candidates for subacromial decompression have more pronounced range of motion deficits, but do not differ in self-reported shoulder function, strength or pain compared to non-candidates. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-4894-6

[41] Internal impingement of the shoulder: An international survey of 261 orthopaedic surgeons. Orthopaedics & Traumatology: Surgery & Research. 2019. DOI: 10.1016/j.otsr.2019.09.007

[42] Is the Disabilities of the Arm, Shoulder and Hand (DASH) Questionnaire Adequate to Assess Individuals With Subacromial Pain Syndrome? Rasch Model and International Classification of Functioning, Disability and Health. Physical Therapy. 2021. DOI: 10.1093/ptj/pzab065

[45] Implantable Subacromial Balloon Spacers in Patients With Massive Irreparable Rotator Cuff Tears: A Systematic Review of Clinical, Biomechanical, and Financial Implications. Arthroscopy, Sports Medicine, and Rehabilitation. 2020. DOI: 10.1016/j.asmr.2020.06.011

[47] The acromiohumeral distance in the MRI should not be used as a decision criterion to assess subacromial space width in shoulders with an intact rotator cuff. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06090-6

[48] Lifestyle factors and subacromial impingement syndrome of the shoulder: potential associations in finnish participants. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07345-w

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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.


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