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Ulnar Collateral Ligament Injury (Tommy John Injury)

Medial UCL valgus instability in overhead athletes: moving valgus/milking exam, stress US/MRI, non-operative rehab, UCL reconstruction (docking/modified-Jobe) and repair with internal brace.

85 citationsUpdated Sep 2026
Illustration: Ulnar Collateral Ligament Injury (Tommy John Injury)

For patients: a plain-language version of this topic is available. See the patient guide.

Overview

Ulnar collateral ligament (UCL) injury management has historically been guided by expert opinion rather than empirical evidence, with a notable lack of comparative data in the literature [20]. The current evidence base is not convincing, and expert consensus should be viewed with caution due to methodological biases [1]. Future high-quality randomized studies are required to establish definitive treatment protocols [1]. While sonography can identify UCL injury [12], the quality of publicly available information on platforms such as YouTube is low, particularly regarding differential diagnoses, accurate surgical indications, and adverse outcomes [13].

Nonoperative treatment offers favorable outcomes for younger patients with acute or partial injuries [11]. However, in professional pitchers, distal UCL tears described on MRI show significantly higher rates of failure with nonoperative management compared to proximal tears [3]. When nonsurgical management fails, UCL reconstruction is a viable option to return the throwing athlete to competition [4]. Primary repair of proximal and distal injuries is a viable alternative in the nonprofessional athlete [5], and primary repair using InternalBrace augmentation demonstrates a predictably high rate of clinical success in properly selected patients [39].

UCL reconstruction is currently the most commonly performed surgical treatment for UCL insufficiency, with a commonly quoted success rate of 85% defined as the ability to return to a preinjury level of play for at least one year [21]. Hybrid fixation techniques result in a low complication rate and allow full recovery to preinjury performance in the majority (85%) of patients [6]. Surgical modifications to reconstruction techniques have yielded decreased postoperative complication rates and improved outcomes compared with prior procedures [19]. Clinically, the initial results of the DANE TJ technique compare favorably with other published techniques [7]. Reconstruction with transposition and stabilization of the ulnar nerve, along with appropriate rehabilitation, effectively corrects medial instability and allows most athletes to return to previous levels of play in less than 1 year [23]. Surgical outcomes in professional baseball players are not significantly influenced by reconstruction technique or graft type usage [26].

Anatomy & Pathophysiology

Ligament Anatomy

The ulnar collateral ligament serves as the primary static constraint of the elbow to valgus stress [59]. The anterior bundle of the medial ulnar collateral ligament is the primary static stabilizer against this force [29]. It originates on the distal osteocartilaginous portion of the medial epicondyle apophysis, with its origin center point located approximately 3 mm from the lateral edge of the bony apophysis [29]. The ligament inserts on the medial aspect of the proximal ulna at and just distal to the sublime tubercle [29]. This insertion site lies deep and anterior to the ulnar nerve [58]. Biomechanically, the anterior band of the anterior bundle demonstrates an isometric strain pattern through elbow range of motion [120], whereas the posterior band exhibits an increasing strain pattern in higher degrees of elbow flexion [120].

Pathophysiology & Mechanism

Ulnar collateral ligament injuries in overhead athletes result from repetitive valgus forces during throwing [18]. A history of repetitive overuse with throwing is most often present in baseball players with this injury [29]. Significant correlations for ulnar collateral ligament injury include high repetition of in-season throwing, play on multiple teams, positions of pitcher and catcher, and continued play through medial elbow pain [29]. While often discussed as an all-or-none injury, ulnar collateral ligament insufficiency is a gradual condition that occurs on a continuum [64]. It remains unclear whether acute worsening of symptoms represents an acute change in pathophysiology or a change in adaptation to longstanding insufficiency [64]. Acute injury may also occur via a valgus weight-bearing event during upper extremity gymnastic weight bearing or through an elbow dislocation [29].

Tearing of the ulnar collateral ligament significantly increases elbow valgus laxity [103]. This increased laxity elongates the ulnar nerve during simulated throwing motion [103]. Furthermore, ulnar collateral ligament injury reduces the resistance of the elbow to valgus loading [124] and increases radiocapitellar contact pressures [124]. Elbow valgus torque independently increases contact pressure in the radiocapitellar joint [93]. Injuries to the ulnar collateral ligament can lead to significant functional impairment and secondary intra-articular damage [59].

Risk factors and biomechanical metrics require collective consideration. Elbow injury risk in pitchers likely reflects the combined influence of velocity, workload, biomechanics, recovery, and individual tissue tolerance rather than spin rate alone [82]. Shoulder flexibility, arm speed, and elbow varus torque are interrelated and should be considered collectively when treating pitchers [95]. Elbow valgus torque is poorly suited as a standalone metric for predicting injury risk due to narrow data ranges, modeling noise, and crude assumptions [86]. With motion capture technology and biomechanists now part of MLB organizations, teams can analyze and improve the biomechanics of their pitchers to reduce elbow varus torque and the injury risk [84]. Injury may be preceded by declines in performance and be associated with subsequent injuries to the shoulder and elbow [63]. No significant relationships between adaptations in shoulder strength or range of motion were related to chronic structural adaptations of the elbow [90]. A reduction in proximal Hounsfield Unit values on CT may reflect localized structural attenuation that is functionally relevant to medial elbow stability [117].

Classification

MRI-Based Classification Systems

Four-Stage MRI System: A proposed MRI-based classification system categorizes ulnar collateral ligament (UCL) injuries into four types based on severity and location [137]. Type I is defined as edema in the UCL only or a low-grade partial tear [144]. Type II is defined as a partial tear of the UCL with no extravasation of fluid on arthrogram or a high-grade partial tear [144]. Type III is defined as a complete full-thickness tear of the UCL with extravasation of fluid on arthrogram [144]. Type IV is defined as a tear or pathology in more than one location on the UCL, such as the ulna and humerus [144]. Valgus stress opening measurements increase with classification severity in this system: Type I 0.13 mm, Type II 0.20 mm, Type III 0.63 mm, and Type IV 0.76 mm [137].

Six-Stage MRI System: A newly proposed 6-stage MRI-based classification system for UCL tears was assessed for intra- and interobserver reliability [130]. The prognostic utility of an MRI-based classification for operative versus nonoperative management of ulnar collateral ligament tears was evaluated at one-year follow-up [54].

Reliability and Diagnostic Limitations

Interobserver and intraobserver reliability of a newly proposed MRI-based classification for UCL tears was assessed using weighted kappa values [130]. Magnetic resonance imaging is not reliable for diagnosing lateral ulnar collateral ligament injuries because an intact ligament often does not appear as a distinct structure and generates artifacts that can be confused with rupture [17]. Preliminary sonographic work provides a framework for developing protocols for diagnosis of injuries to the distal ulnar collateral ligament [16].

Prognostic and Risk Classification

Elbow UCL Injury Prognosis Score: This logistic regression model identifies patient- and injury-specific factors predictive of successful return to play after nonoperative management in baseball players [35]. Dominant arm total arc of motion, external rotation range of motion, and internal rotation range of motion were not risk factors for ulnar collateral ligament injury [25]. Negative prognostic factors for medial collateral ligament injury include prior elbow surgery, valgus extension overload syndrome, ulnohumeral chondromalacia, associated flexor-pronator muscle tears, and calcification about the ligament [62].

Epidemiological and Demographic Classification

Ulnar collateral ligament injuries are classified as occurring primarily in boys aged under 15 years before apophyseal closure [65]. In a study of collegiate baseball players, 85.8% of players who underwent UCL surgery were pitchers [142]. In the same cohort, 65.7% of players who underwent UCL surgery were underclassmen (freshmen and sophomores) [142]. Additionally, 48.5% of UCL surgeries occurred during the in-season interval [142]. The incidence of ulnar collateral ligament injuries is increasing in youth athletes [57]. Ulnar collateral ligament injuries result from repetitive valgus forces during throwing and are not uncommon in overhead athletes [18].

Clinical Presentation

History and Mechanism

Ulnar collateral ligament injuries result from repetitive valgus forces during throwing [18]. In baseball players, a history of repetitive overuse with throwing is most often present [29]. Significant correlations for injury include high repetition of in-season throwing, play on multiple teams, positions of pitcher and catcher, and continued play through medial elbow pain [29]. Increased pitch velocity and workload are common risk factors in baseball players [46]. Conversely, dominant arm total arc of motion, external rotation range of motion, or internal rotation range of motion were not risk factors for ulnar collateral ligament injury [25]. The ulnar collateral ligament may also be injured acutely with a valgus weight-bearing event during upper extremity gymnastic weight bearing or with an elbow dislocation [29]. There has been an alarming increase in the incidence of ulnar collateral ligament injuries among youth patients [57].

Physical Examination

Ulnar collateral ligament injuries are a common source of pain and disability in overhead and throwing athletes [45]. Patients may present with local tenderness to palpation and loss of elbow extension [29]. Local pain focally and distal to the ulnar collateral ligament origin and extending to the sublime tubercle region is common [29]. Pain with valgus stress tests is common in patients with ulnar collateral ligament injury [29].

Imaging

Plain radiographs may often show chronic changes of valgus stress in the ulnar collateral ligament injured elbow [29]. In the case of a partial or osteocartilaginous sleeve avulsion, a radiodense fragment or fleck may be identified on radiographs [29]. Ultrasound or MRI may be employed to investigate the soft tissue portion of the ulnar collateral ligament [29]. MRI with joint arthrogram is most commonly used to investigate the soft tissue portion of the ulnar collateral ligament [29]. A low-grade (I or II) partial injury of the ulnar collateral ligament may be difficult to definitively assess on MRI [29]. Complete mid-substance or origin, insertional injuries (III) of the ulnar collateral ligament may be more clear on MRI [29]. Thickening of the medial ulnar collateral ligament in the throwing arm of asymptomatic and uninjured players may begin by the time the players reach high school [27]. Changes present in the ulnar collateral ligament and detectable on ultrasound may help distinguish elbows at risk for later clinical ulnar collateral ligament insufficiency [61]. The ulnar collateral ligament responds to stress in professional pitchers [40]. The ulnar collateral ligament responds to stress and rest in professional pitchers [113].

Investigations

Plain radiography: Plain radiographs may demonstrate chronic changes associated with valgus stress in the ulnar collateral ligament injured elbow [29]. Radiodense fragments or flecks resulting from partial or osteocartilaginous sleeve avulsions may also be identified on plain radiographs [29]. No numerical value can confidently determine the pathologic status of the ulnar collateral ligament of the elbow when using stress radiography [131].

MRI: MRI with joint arthrogram is the most commonly used imaging modality to investigate the soft tissue portion of the ulnar collateral ligament [29]. Complete mid-substance or origin and insertional injuries (Grade III) are more clearly identified on MRI than low-grade (Grade I or II) partial injuries [29]. The clinical outcomes of both nonoperative and surgical treatment for symptomatic elbows with bone marrow edema in the sublime tubercle are unclear [55].

Ultrasound: Valgus stress ultrasound is useful for identifying complete medial ulnar collateral ligament tears but is less sensitive for detecting partial tears [132].

Arthroscopy: Arthroscopic techniques provide safe and objective means to evaluate and diagnose both medial and lateral elbow instability despite being more invasive than ultrasonography and radiography [133].

Treatment

Non-Operative

Nonoperative management for ulnar collateral ligament (UCL) insufficiency typically involves a minimum of three months of rest combined with rehabilitation exercises [47]. In athletes with UCL insufficiency, this conservative approach allows return to the previous level of competition in 42% of cases, with those who succeed returning at an average of 24.5 weeks after diagnosis [47]. A systematic review of return-to-sport after non-operative management reports a mean time of 91.9 ± 46.2 days (13.1 weeks; range, 1–54 weeks) [70]. Overall return-to-play rates for partial UCL injuries in overhead athletes range between 42% and 100%, with a mean of 78% ± 20% [77]. The most frequently reported components of nonoperative rehabilitation protocols include a period of rest, stretching, strengthening, and a throwing program [77]. No findings obtained through history or physical examination assist in predicting the success of nonoperative treatment for UCL insufficiency [47].

Non-operative treatment is likely to be more successful in younger players, lower grade tears, and humeral-sided injuries [129]. Incomplete UCL injuries in professional baseball players can be successfully treated nonoperatively in the majority of cases [148], and UCL injuries in high school baseball players can be successfully treated nonoperatively in most cases [146]. Both operative and non-operative treatments can be offered as successful treatment options for UCL injuries in gymnasts [141]. However, in professional baseball pitchers, distal UCL tears described on MRI show significantly higher rates of failure with nonoperative management compared to proximal tears [3]. There is no current consensus regarding the true efficacy of platelet-rich plasma therapy for partial UCL tears [75], nor regarding the utilization of autologous stem cell treatments in the management of UCL injuries [75].

Operative

Indications: UCL reconstruction is a viable option to return the throwing athlete to competition when nonsurgical management fails [4]. It remains unclear which patients are the ideal candidates for UCL reconstruction versus repair [74]. Low-level, high-bias evidence demonstrates that the overall return to sport proportion is higher than return to sport at previous level, regardless of treatment type for UCL injury [43].

Surgical Approach / Technique: UCL reconstruction is currently the most commonly performed surgical treatment option for UCL insufficiency [21]. The commonly quoted success rate for UCL reconstruction is 85%, defined as the ability to return to a preinjury level of play for at least one year [21]. Reconstruction based on a hybrid fixation technique results in a low complication rate and allows full recovery to preinjury level of performance in 85% of patients [6]. Utilizing the docking technique results in a significantly higher rate of return to play and a lower complication rate when compared with the Jobe and modified Jobe techniques [42]. Reconstruction with subcutaneous ulnar nerve transposition was found to be effective in correcting valgus elbow instability and allowed 83% of athletes to return to previous or higher level of competition in less than 1 year [106]. Surgical modifications, including a muscle-splitting approach without transposition of the ulnar nerve, yielded a decreased postoperative complication rate and improved outcomes compared with prior procedures [19]. Advances in the surgical technique of UCL reconstruction have minimized postoperative complications [147]. Most athletes are able to return to a high level of competition following surgical treatment of medial elbow injuries [147]. The success rate of UCL reconstruction in high school baseball players is nearly equal to that in more mature groups of throwers [97].

Repair and Augmentation: UCL repair has favorable outcomes in select patients with specific tear type patterns [71]. Clinical outcomes for UCL repair have shown return to play rates of 92–97% with a mean time of 2.5–6 months post-operatively [71]. Biomechanical data comparing UCL repair to reconstruction techniques have shown improved resistance to common forces applied to the elbow during overhead activities [71]. Suture tape augmentation dramatically improves stability of ligament repair without over-constraining the elbow [71]. UCL repair with suture tape augmentation is a viable surgical treatment option for UCL injury [72] and is associated with notably quicker return to sport compared with UCL reconstruction [72]. For complex elbow instability, ligament repair with suture-tape augmentation of the lateral UCL results in acceptable functional outcomes and a reoperation rate comparable with other joint stabilization procedures [41].

Other Considerations: Both UCL reconstruction and repair show favorable outcomes at minimum two-year follow-up in non-throwing athletes [44]. In non-throwing athletes, 93% or greater returned to play with good functional outcomes and minimal complications following UCL reconstruction or repair [44]. Excellent clinical outcomes were identified following UCL procedures in non-baseball throwing athletes with a 92% return to play rate [149]. Routine diagnostic arthroscopy with UCL reconstruction does not reduce the need for future valgus extension overload–related surgeries [8]. The observed decrease in routine diagnostic arthroscopy utilization with UCL reconstruction over time appears justified based on findings that it does not reduce future surgery needs [8]. There was no difference in return to play rate following UCL reconstruction in baseball players with and without posteromedial impingement treated with arthroscopic resection [118]. Posteromedial osteophyte resection in baseball players undergoing UCL reconstruction decreases patient-reported satisfaction and throwing control [118].

Complications

Nerve palsy: Surgical modifications to ulnar collateral ligament reconstruction, specifically a muscle-splitting approach without transposition of the ulnar nerve, yield a decreased postoperative complication rate compared with prior procedures [19].

Other Considerations: Ulnar collateral ligament reconstruction based on a hybrid fixation technique results in a low complication rate [6]. Utilizing the docking technique results in a lower complication rate when compared with the Jobe and modified Jobe techniques [42]. In non-throwing athletes, both UCL reconstruction and UCL repair show minimal complications at minimum two-year follow-up [44]. The quality of ulnar collateral ligament-related information on YouTube is low, with thorough discussions of adverse outcomes being among the most lacking information [13].

Recovery

Full activity (months): Following ulnar collateral ligament repair and lateral collateral ligament reconstruction, full activity is permitted at 6 months, with participation in contact sports allowed at 1 year [10].

Other Considerations: Although injury to the UCL was once a career-ending event in overhead athletes, the development and continued evolution of UCL reconstruction have made return to previous or higher levels of athletic participation highly likely [67]. Most major league pitchers return from ulnar collateral ligament reconstruction by the second season after surgery, with no statistical change in mean innings pitched, earned run average, or walks and hits per inning pitched from preinjury levels [151]. In non-throwing athletes, both UCL reconstruction and UCL repair demonstrate favorable outcomes at minimum two-year follow-up, with 93% or greater returning to play with good functional outcomes and minimal complications [44]. Clinically, augmented UCL repair has demonstrated excellent return to previous level of play and Kerlan Jobe Orthopaedic Clinic scores, accompanied by modest complications and time to return [150]. Following UCL repairs and reconstructions, elbow range of motion is reliably preserved or improved, following a predictable trajectory of rapid improvement within the first 2 to 4 months [56]. Further investigation is necessary to determine long-term outcomes for return to play after UCL reconstruction of the elbow in adolescent throwing athletes [143]. The current evidence for ulnar collateral ligament injury treatment is not convincing; while expert consensus provides guidance, it should be viewed with caution due to methodological biases, and future high-quality randomized studies are required [1].

Key Evidence

  • [L5] The current evidence for ulnar collateral ligament injury treatment is not convincing, and while expert consensus provides guidance, it should be viewed with caution due to methodological biases; future high-quality randomized studies are required. [1] (10.1016/j.arthro.2023.02.003)
  • [L3] No significant difference in clinical outcome or range of motion was observed after direct repair of traumatic tears of the lateral ulnar collateral ligament between acute and delayed treatment cohorts. [2] (10.1016/j.jhsa.2014.02.011)
  • [L3] In professional pitchers, distal ulnar collateral ligament tears described on MRI show significantly higher rates of failure with nonoperative management compared to proximal tears. [3] (10.1177/2325967116s00169)
  • [L5] Failing nonsurgical management, ulnar collateral ligament reconstruction is a viable option to return the throwing athlete to competition. [4] (10.5435/jaaos-22-05-315)
  • [L4] Primary repair of proximal and distal injuries of the medial ulnar collateral ligament is a viable alternative in the nonprofessional athlete. [5] (10.1177/0363546508315201)
  • [L4] Ulnar collateral ligament reconstruction based on a hybrid fixation technique results in a low complication rate and allows full recovery to preinjury level of performance in the majority (85%) of patients. [6] (10.1177/0363546510385401)
  • [L4] Clinically, the initial results compare favorably with other published techniques of elbow ulnar collateral ligament reconstruction. [7] (10.1177/0363546507305802)
  • [L1] The observed decrease in routine diagnostic arthroscopy utilization with ulnar collateral ligament reconstruction over time appears justified based on these findings. [8] (10.1016/j.jse.2021.08.004)
  • [L5] Surgical management is indicated when the elbow remains unstable, with the lateral ulnar collateral ligament being the most critical structure to repair or reconstruct. [9] (10.1016/j.hcl.2016.08.003)
  • [L5] Nonoperative treatment can offer favorable outcomes for younger patients with acute or partial ulnar collateral ligament injuries. [11] (10.1016/j.otsm.2020.150733)
  • [L4] Sonography can identify injury of the ulnar collateral ligament. [12] (10.1007/s00256-002-0558-0)
  • [L4] The quality of ulnar collateral ligament-related information on YouTube is low, with differential diagnoses, accurate surgical indications, and thorough discussions of adverse outcomes being the most lacking information. [13] (10.1016/j.asmr.2023.100769)
  • [L4] There is a paucity of literature describing the return-to-competition process after ulnar collateral ligament reconstruction in overhead throwing athletes. [14] (10.1177/03635465211016839)
  • [L4] Patients with concomitant ulnar collateral ligament insufficiency had less optimal outcomes than those with isolated posteromedial impingement. [15] (10.1016/j.jse.2016.09.007)
  • [L4] This preliminary work provides a framework for developing protocols for diagnosis of injuries to the distal ulnar collateral ligament. [16] (10.7863/ultra.33.8.1485)
  • [L4] Magnetic resonance imaging is not reliable for diagnosing lateral ulnar collateral ligament injuries at the present time because an intact ligament often does not appear as a distinct structure and generates artifacts that can be confused with rupture. [17] (10.1016/j.jse.2003.12.013)
  • [L5] This article reviews the anatomy, biomechanics, pathophysiology, diagnosis, and treatment options for ulnar collateral ligament injuries in overhead athletes, emphasizing that the injury is not uncommon and results from repetitive valgus forces during throwing. [18] (10.1016/j.csm.2004.05.002)
  • [L4] These surgical modifications to the ulnar collateral ligament reconstruction yielded a decreased postoperative complication rate and improved outcomes compared with the results of prior procedures. [19] (10.1067/mse.2001.112881)
  • [L5] Management of lateral elbow epicondylalgia and medial ulnar collateral ligament injury has been guided mostly by expert opinion rather than empirical evidence, with a lack of comparative data in the literature. [20] (10.1016/j.jse.2023.07.034)
  • [L4] Ulnar collateral ligament reconstruction is currently the most commonly performed surgical treatment option for UCL insufficiency, with a commonly quoted success rate of 85% defined as the ability to return to a preinjury level of play for at least one year. [21] (10.1136/bjsm.2005.025072)
  • [L4] Reconstruction of the ulnar collateral ligament, with transposition and stabilization of the ulnar nerve and appropriate rehabilitation, was found to be effective in correcting medial instability of the elbow and allowed most athletes to return to previous levels of play in less than 1 year. [23] (10.1177/03635465000280011401)
  • [L2] Dominant arm total arc of motion, external, or internal rotation range of motion were not risk factors for ulnar collateral ligament injury. [25] (10.1016/j.jse.2018.08.018)
  • [L3] Surgical outcomes in professional baseball players are not significantly influenced by ulnar collateral ligament reconstruction technique or graft type usage. [26] (10.1177/2325967118s00087)
  • [L4] Thickening of the medial ulnar collateral ligament in the throwing arm of asymptomatic and uninjured players may begin by the time the players reach high school. [27] (10.1007/s10396-014-0605-1)
  • [L4] The use of suture button fixation for repair of lateral ulnar collateral ligament has not been previously described. [32] (10.1016/j.eats.2023.10.004)
  • [L3] [35] (10.1177/03635465251366318)
  • [L5] Primary repair of the ulnar collateral ligament (UCL) using InternalBrace augmentation seems to have a predictably high rate of clinical success in properly selected patients. [39] (10.1016/j.csm.2020.04.001)
  • [L3] The ulnar collateral ligament responds to stress in professional pitchers. [40] (10.1177/2325967119s00372)
  • [L4] For complex elbow instability, ligament repair with suture-tape augmentation of the lateral ulnar collateral ligament results in acceptable functional outcomes and a reoperation rate comparable with other joint stabilization procedures. [41] (10.1016/j.jhsa.2022.10.016)
  • [L4] Ulnar collateral ligament reconstruction utilizing the docking technique results in a significantly higher rate of return to play and a lower complication rate when compared with the Jobe and modified Jobe techniques. [42] (10.1177/0363546513509051)
  • [L1] Low-level, high-bias evidence demonstrates overall return to sport proportion is higher than return to sport at previous level, regardless of treatment type for ulnar collateral ligament injury. [43] (10.1016/j.jse.2017.12.003)
  • [L4] Both UCL reconstruction and UCL repair show favorable outcomes at minimum two-year follow-up in non-throwing athletes. 93% or greater returned to play with good functional outcomes and minimal complications. [44] (10.1177/2325967121s00551)
  • [L5] [45] (10.5435/jaaos-d-24-00392)
  • [L3] [46] (10.1136/jisakos-2018-000226)
  • [L4] [47] (10.1177/03635465010290010601)
  • [L4] [54] (10.1016/j.jse.2018.11.063)
  • [L3] [55] (10.1177/03635465241259472)
  • [L4] Following UCL repairs and reconstructions, elbow ROM is reliably preserved or improved with a predictable trajectory of rapid improvement within the first 2 to four months. [56] (10.1016/j.jse.2025.10.002)
  • [Paper] There has been an alarming increase in the incidence of ulnar collateral ligament (UCL) injuries among youth patients. [57] (10.2106/jbjs.rvw.25.00060)
  • [L4] The ulnar collateral ligament is the primary static constraint of the elbow to valgus stress, and injuries can lead to significant functional impairment and secondary intra-articular damage. [59] (10.1111/sae.12014)
  • [L2] Our data suggests that changes present in the UCL and detectable on ultrasound may help distinguish elbows at risk for later clinical UCL insufficiency. [61] (10.1177/2325967115s00162)
  • [L5] [62] (10.2106/jbjs.rvw.m.00057)
  • [L4] Injury may be preceded with declines in performance and be associated with subsequent injuries to the shoulder and elbow. [63] (10.1177/2325967117s00217)
  • [L5] [64] (10.1016/j.jhsa.2014.04.011)
  • [L3] [65] (10.1177/03635465241252156)
  • [L4] Although injury to the UCL was once a career-ending injury in overhead athletes, development and continued evolution of UCL reconstruction have made return to previous or higher level of athletic participation in sports highly likely. [67] (10.1177/0363546508319053)
  • [L3] [70] (10.1177/17585732241235631)
  • [L4] [71] (10.1007/s12178-021-09698-4)
  • [L5] [72] (10.1016/j.arthro.2025.01.017)
  • [L5] [74] (10.1016/j.arthro.2022.12.033)
  • [L4] [75] (10.1007/s12178-020-09637-9)
  • [L4] [77] (10.1177/1941738119853589)
  • [L4] Elbow injury risk in pitchers likely reflects the combined influence of velocity, workload, biomechanics, recovery, and individual tissue tolerance rather than spin rate alone. [82] (10.1177/2325967126s00497)
  • [L2] With motion capture technology and biomechanists now part of MLB organizations, teams can analyze and improve the biomechanics of their pitchers to reduce elbow varus torque and the injury risk. [84] (10.1177/23259671251351339)
  • [L5] Elbow valgus torque is poorly suited as a standalone metric for predicting injury risk due to narrow data ranges, modeling noise, and crude assumptions; future efforts should focus on integrated, longitudinal metrics rather than single-session proxies. [86] (10.1002/arj.70098)
  • [L3] However, no significant relationships between adaptations in shoulder strength or ROM were related to chronic structural adaptations of the elbow. [90] (10.1177/03635465251317509)
  • [L5] Elbow valgus torque increases contact pressure in the radiocapitellar joint. [93] (10.1177/0363546513490652)
  • [L4] Shoulder flexibility, arm speed, and elbow varus torque are interrelated and should be considered collectively when treating pitchers. [95] (10.1177/0363546517719047)
  • [L3] The success rate of ulnar collateral ligament reconstruction in high school baseball players is nearly equal to that in more mature groups of throwers. [97] (10.1177/0363546503262166)
  • [L5] Tearing of the UCL significantly increased elbow valgus laxity, which in turn elongated the ulnar nerve during simulated throwing motion. [103] (10.1016/j.jse.2019.02.009)
  • [L4] Ulnar collateral ligament reconstruction with subcutaneous ulnar nerve transposition was found to be effective in correcting valgus elbow instability in the overhead athlete and allowed most athletes (83%) to return to previous or higher level of competition in less than 1 year. [106] (10.1177/0363546510378100)
  • [L3] The ulnar collateral ligament responds to stress and rest in professional pitchers. [113] (10.1177/2325967120s00130)
  • [L3] A reduction in proximal HU values may reflect localized structural attenuation that is functionally relevant to medial elbow stability. [117] (10.1177/23259671261472961)
  • [L3] There was no difference in return to play rate following ulnar collateral ligament reconstruction in baseball players with and without posteromedial impingement treated with arthroscopic resection. [118] (10.1016/j.asmr.2023.04.012)
  • [L5] The anterior band of the anterior bundle of the UCL shows an isometric strain pattern through elbow range of motion, while the posterior band shows an increasing strain pattern in higher degrees of elbow flexion. [120] (10.1007/s00167-014-3482-7)
  • [L5] UCL injury increases radiocapitellar contact pressures and reduces resistance of the elbow to valgus loading. [124] (10.1016/j.jse.2010.09.011)
  • [L3] Non-operative treatment of UCL injuries will likely be more successful in younger players, lower grade tears, and humeral-sided injuries. [129] (10.1177/2325967119s00311)
  • [L2] [130] (10.1177/0363546518786970)
  • [L3] No numerical value can confidently determine the pathologic status of the ulnar collateral ligament of the elbow when using stress radiography. [131] (10.1177/03635465010290050601)
  • [L3] Valgus stress ultrasound is useful for identifying complete medial ulnar collateral ligament tears but is less sensitive for detecting partial tears. [132] (10.1016/j.jse.2019.12.005)
  • [Paper] Despite the invasive nature of arthroscopy in comparison to modalities such as ultrasonography and radiography, these described techniques provide safe and objective means to evaluate and diagnose both medial and lateral elbow instability. [133] (10.1016/j.eats.2023.04.029)
  • [L4] [137] (10.1016/j.jse.2016.05.006)
  • [L4] Both operative and non-operative treatments can be offered as successful treatment options for UCL injuries in gymnasts. [141] (10.1177/2325967121s00200)
  • [L4] [142] (10.1177/2325967118764657)
  • [L4] Further investigation is necessary to determine long-term outcomes for return to play after UCL reconstruction of the elbow in adolescent throwing athletes. [143] (10.1177/0363546520934778)
  • [L4] [144] (10.1177/03635465221150507)
  • [L3] UCL injuries in high school baseball players can be successfully treated nonoperatively in most cases. [146] (10.1016/j.jse.2020.09.022)
  • [L5] Advances in the surgical technique of UCL reconstruction have minimized postoperative complications, and most athletes are able to return to a high level of competition following both nonoperative and surgical treatment of medial elbow injuries. [147] (10.1016/j.hcl.2016.08.013)
  • [L4] Incomplete UCL injuries in professional baseball players can be successfully treated nonoperatively in the majority of cases. [148] (10.1177/0363546515621756)
  • [L4] We identified excellent clinical outcomes following UCL procedures in non‐baseball throwing athletes with a 92% return to play rate and high surgical satisfaction and functional outcome scores. [149] (10.1177/2325967121s00577)
  • [L4] Clinically, augmented UCL repair demonstrated excellent return to previous level of play and Kerlan Jobe Orthopaedic Clinic scores with modest complications and time to return. [150] (10.1016/j.arthro.2023.09.030)
  • [L2] Most major league pitchers return from ulnar collateral ligament reconstruction by the second season after surgery with no statistical change in mean innings pitched, earned run average, or walks and hits per inning pitched from preinjury levels. [151] (10.1177/0363546506296737)

See Also

References

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