AC Joint Osteoarthritis Info Evidence

Overview

• Asymptomatic AC-OA remained asymptomatic in 90% of patients over a 7-year period [2].
• Untreated ACJ osteoarthritis, whether symptomatic or not, encountered during arthroscopic rotator cuff repair is associated with a low percentage of failure [3].
• Radiographic ACJ osteoarthritis is common in patients undergoing reverse shoulder arthroplasty [7].
• Severe acromioclavicular joint osteoarthritis is associated with acromial stress fractures after reverse shoulder arthroplasty [7].
• Both open and arthroscopic resection arthroplasty techniques provide predictable pain relief for symptomatic AC osteoarthritis [8].
• Open and arthroscopic resection arthroplasty techniques have unique sets of potential complications that may be minimized with improved understanding of anatomy, biomechanics, and meticulous surgical technique [8].
• Limited distal clavicle excision reduced pain and improved shoulder function at midterm follow-up in patients with AC joint osteoarthritis resistant to conservative treatment [9].
• A distinction between symptomatic and asymptomatic radiographic AC OA is unnecessary as all patients were equally satisfied with the outcome of preoperative acromioclavicular injection [6].
• Further characterisation of patients in whom mild arthroscopic findings of OA of the AC joint are clinically significant and warrant resection is needed [1].
• Acromioclavicular joint arthritis is not an indication for routine distal clavicle excision in arthroscopic rotator cuff repair [3].
• Clinicians should consider overreduction of the AC joint because it may lead to favorable radiological results [5].
• The authors recommend anatomic reconstruction procedures for the treatment of chronic complete AC dislocations [21].

Anatomy & Pathophysiology

• Anatomic techniques that address both coracoclavicular ligaments and the AC capsule are recommended to restore horizontal and vertical stability while allowing physiological rotation [10].
• None of the reconstruction strategies completely restored the shoulder girdle to its preinjured state [26].
• Kinematic changes resulting from AC joint dislocation could be a potential source of pain and dysfunction in the shoulder [27].
• Scapular and clavicular kinematics were affected in AC separation models [28].
• The position of the hook portion of a clavicle hook plate can predispose anatomic structures to post-operative complications of subacromial impingement and bony erosion [29].
• Future research should focus on addressing horizontal and rotational instability to restore native physiological and biomechanical properties of the AC joint [35].
• Coracoclavicular reconstruction with augmentation of the acromioclavicular joint provides improved horizontal stability compared to isolated coracoclavicular reconstruction [41].
• Adding a fixation of the AC joint minimizes lateral tilting of the scapula and maintains a more anatomic reposition result over time [45].

Classification

• Asymptomatic acromioclavicular osteoarthritis diagnosed by MRI remained asymptomatic in 90% of patients over a 7-year period [2].
• Untreated acromioclavicular joint osteoarthritis, whether symptomatic or not, encountered during arthroscopic rotator cuff repair is associated with a low percentage of failure [3].
• Mild arthroscopic findings of acromioclavicular joint osteoarthritis may be clinically significant and warrant resection, but further characterization of such patients is needed [1].
• Severe acromioclavicular joint osteoarthritis is associated with acromial stress fractures after reverse shoulder arthroplasty [7].
• Radiographic acromioclavicular joint osteoarthritis is common in patients undergoing reverse shoulder arthroplasty [7].
• Osteolytic changes in the acromioclavicular joint seemed to be associated with incongruity of the joint but did not correlate with clinical results [11].
• The acromial center line to dorsal clavicle radiographic measurement and the use of the Alexander view provide a more realistic appreciation of true acromioclavicular joint displacement, especially in defining watershed cases (Rockwood types IIIA, IIB, and IV) [12].
• Evaluating the integrity of the capsuloligamentous structures stabilizing the acromioclavicular joint is reproducible and provides additional information on the severity of the injury [24].
• Injuries to the sternoclavicular joint are uncommon, and recognition and classification are critical to proper management to minimize long-term sequelae [16].
• Some persistent pain and osteoarthritis progression remain concerns in the arthroscopic revision of failed open anterior stabilization of the shoulder [4].

Clinical Presentation

• Asymptomatic AC-OA remained asymptomatic in 90% of patients over a 7-year period [2].
• Untreated ACJ osteoarthritis, whether symptomatic or not, encountered during arthroscopic rotator cuff repair is associated with a low percentage of failure [3].
• Preventive arthroscopic distal clavicle resection is not recommended in patients with radiological but asymptomatic ACJ arthritis [19].
• Further characterisation of patients in whom mild arthroscopic findings of OA of the AC joint are clinically significant and warrant resection is needed [1].
• A distinction between symptomatic and asymptomatic radiographic AC OA is unnecessary, as all patients were equally satisfied with the outcome of preoperative acromioclavicular injection [6].
• Osteolytic changes seemed to be associated with incongruity of the AC joint, but did not correlate with clinical results [11].
• Additional research is needed to determine the main cause of pain in isolated acromioclavicular osteoarthritis and to compare clinical outcomes of intra-articular versus extra-articular injections [13].
• Risk factors for subsequent distal clavicle excision after rotator cuff repair include tenderness to palpation at the AC joint, female sex, and surgery on the dominant side [18].
• Subsequent distal clavicle excision was performed in 40% of cases with a combination of the three identified risk factors (tenderness to palpation, female sex, dominant side surgery) [18].
• Recurrence of the initial dislocation after arthroscopically assisted reduction appears to be related to the onset of degenerative ACJ arthropathy [14].
• Some persistent pain and osteoarthritis progression remain concerns in the revision of failed open anterior stabilization of the shoulder [4].

Investigations

• Asymptomatic AC-OA remained asymptomatic in 90% of patients over a 7-year period [2].
• Untreated ACJ osteoarthritis, whether symptomatic or not, encountered during arthroscopic rotator cuff repair is associated with a low percentage of failure [3].
• Preventive arthroscopic distal clavicle resection (DCR) is not recommended in patients with radiological but asymptomatic ACJ arthritis [19].
• Further characterization is needed to determine which patients with mild arthroscopic findings of AC joint OA are clinically significant and warrant resection [1].
• Radiographic ACJ osteoarthritis is common in patients undergoing reverse shoulder arthroplasty (RSA) [7].
• Severe ACJ osteoarthritis is associated with acromial stress fractures after reverse shoulder arthroplasty [7].
• Osteolytic changes in the AC joint seemed to be associated with incongruity but did not correlate with clinical results [11].
• Patients with edema on MRI were more likely to present with pain than patients without edema [43].
• Subchondral bone edema on histologic examination was more frequent in patients with pain [43].
• The outcomes of a preoperative AC injection suggest that a distinction between symptomatic and asymptomatic radiographic AC OA is unnecessary, as all patients were equally satisfied with the outcome [6].
• Additional research is needed to determine the main cause of pain and to compare clinical outcomes of intra-articular versus extra-articular steroid injections for isolated AC osteoarthritis [13].
• Risk factors for subsequent distal clavicle excision after rotator cuff repair include tenderness to palpation at the AC joint, female sex, and surgery on the dominant side [18].
• Subsequent distal clavicle excision was performed in 40% of cases with a combination of the three identified risk factors (tenderness, female sex, dominant side) [18].
• The arthroscopic approach offers an advantage in diagnosing and treating occult intra-articular pathology during distal clavicle excision [20].
• Some persistent pain and osteoarthritis progression remain concerns in the revision of failed open anterior stabilization of the shoulder using arthroscopy [4].
• Evaluating the integrity of the capsuloligamentous structures stabilizing the AC joint is reproducible and provides additional information on injury severity, which may influence treatment decisions [24].
• The AC-DC measurement and use of the Alexander view provide a more realistic appreciation of true AC joint displacement, particularly in defining watershed cases (IIIA/IIB/IV) [12].
• Radiological failures were observed in 41% of cases in a prospective multicenter study of arthroscopic acute AC dislocation fixation [50].

Treatment

Non-Operative Management

• Conservative therapy is a valid initial treatment option for Rockwood Type V acromioclavicular dislocations [15].
• Non-operative reduction and stabilization is a valuable treatment option for acute high-grade acromioclavicular joint separations [33].
• Nonoperative treatment is helpful for most patients with painful conditions of the acromioclavicular joint, although those with osteolysis may need to modify their activities [44].
• Conservative and surgical treatments are both effective in the management of acromioclavicular joint osteoarthritis [17].
• Acromioclavicular injections offer a 1-year success rate of 47% in patients with acromioclavicular osteoarthritis [22].
• Additional research is needed to determine the main cause of pain and to compare clinical outcomes of intra-articular versus extra-articular steroid injections for isolated acromioclavicular osteoarthritis [13].

Operative Management

• Both open and arthroscopic resection arthroplasty techniques provide predictable pain relief for symptomatic acromioclavicular osteoarthritis [8].
• Limited distal clavicle excision reduces pain and improves shoulder function at midterm follow-up in patients with acromioclavicular joint osteoarthritis resistant to conservative treatment [9].
• Untreated acromioclavicular joint osteoarthritis, whether symptomatic or not, encountered during arthroscopic rotator cuff repair is associated with a low percentage of failure [3].
• Further characterization is needed to identify patients in whom mild arthroscopic findings of acromioclavicular joint osteoarthritis are clinically significant and warrant resection [1].
• Conversion to anatomic coracoclavicular ligament reconstruction shows similar clinical outcomes compared to successful non-operative treatment in chronic primary type III to V acromioclavicular joint injuries at a minimum 5-year follow-up [49].
• The authors recommend anatomic reconstruction procedures for the treatment of chronic complete acromioclavicular dislocations [21].
• Osteoarthritis is associated with poorer final clinical outcomes after rotator cuff repair, and an unhealed or re-torn cuff increases the risk of osteoarthritis [23].

Diagnostic Considerations

• A distinction between symptomatic and asymptomatic radiographic acromioclavicular osteoarthritis appears unnecessary, as all patients were equally satisfied with the outcome of preoperative acromioclavicular injection [6].
• Asymptomatic acromioclavicular osteoarthritis diagnosed by MRI remained asymptomatic in 90% of patients over a 7-year course [2].
• Some persistent pain and osteoarthritis progression remain concerns following arthroscopy in the revision of failed open anterior stabilization of the shoulder [4].

Complications

• Asymptomatic AC-OA remained asymptomatic in 90% of patients over a 7-year period [2].
• Untreated ACJ osteoarthritis, whether symptomatic or not, encountered during arthroscopic rotator cuff repair is associated with a low percentage of failure [3].
• Osteoarthritis is associated with poorer final clinical outcomes after rotator cuff repair [23].
• An unhealed or re-torn rotator cuff increases the risk of developing osteoarthritis [23].
• Severe AC joint osteoarthritis is associated with acromial stress fractures after reverse shoulder arthroplasty [7].
• Radiographic ACJ osteoarthritis is common in patients undergoing reverse shoulder arthroplasty [7].
• Some persistent pain and osteoarthritis progression remain concerns following arthroscopy in revision of failed open anterior stabilization of the shoulder [4].
• Recurrence of the initial dislocation after arthroscopically assisted reduction of acute AC joint dislocation appears to be related to the onset of degenerative ACJ arthropathy [14].
• Treatment of acute grade III and IV AC dislocations by synthetic ligament reconstruction carries a risk of significant early osteolysis [25].
• Open and arthroscopic AC joint reconstruction techniques have no differences in loss of reduction, complication rate, or revision rate [38].
• Both open and arthroscopic resection arthroplasty techniques provide predictable pain relief for symptomatic AC osteoarthritis but each has a unique set of potential complications [8].

Recovery

• Asymptomatic acromioclavicular osteoarthritis diagnosed by MRI remained asymptomatic in 90% of patients over a 7-year period [2].
• Untreated acromioclavicular joint osteoarthritis, whether symptomatic or not, encountered during arthroscopic rotator cuff repair is associated with a low percentage of failure [3].
• Limited distal clavicle excision for acromioclavicular joint osteoarthritis resistant to conservative treatment reduced pain and improved shoulder function at midterm follow-up [9].
• Acromioclavicular injections offer a 1-year success rate of 47% in patients with acromioclavicular osteoarthritis [22].
• A preoperative acromioclavicular injection study suggested that distinguishing between symptomatic and asymptomatic radiographic acromioclavicular osteoarthritis is unnecessary, as all patients were equally satisfied with the outcome [6].
• Osteolytic changes in the acromioclavicular joint seemed to be associated with incongruity but did not correlate with clinical results [11].
• Recurrence of initial acromioclavicular joint dislocation appears to be related to the onset of degenerative acromioclavicular joint arthropathy [14].
• Treatment of acute grade III and IV acromioclavicular dislocations using synthetic ligament reconstruction gave satisfactory results in terms of recovery of strength, but evolution is not risk-free due to the onset of significant early osteolysis [25].
• Arthroscopic coracoclavicular ligament reconstruction with double-bundle soft tissue allograft for chronic type V acromioclavicular dislocations showed sustained and statistically significant improvements in functional outcomes, high rates of return to sport, and maintenance of active-duty military status at minimum 10-year follow-up [39].
• Minimally invasive coracoclavicular ligament augmentation with a flip button/polydioxanone repair for total acromioclavicular joint dislocation revealed excellent radiologic and clinical results with no subluxations or dislocations noted in short-term follow-up [48].
• Some persistent pain and osteoarthritis progression remain concerns in the arthroscopic revision of failed open anterior stabilization of the shoulder [4].
• Type V acromioclavicular dislocations may be given a trial of conservative therapy [15].

Key Evidence

• [L2] Further characterisation of patients in whom mild arthroscopic findings of OA of AC joint are clinically significant and warrant resection is needed. [1] (10.1007/s00167-014-3114-2)
• [L2] Asymptomatic AC-OA remained asymptomatic in 90% over 7 years. [2] (10.1016/j.jse.2019.04.004)
• [L2] Untreated ACJ osteoarthritis, symptomatic or not, encountered during arthroscopic RCR is associated with a low percentage of failure. [3] (10.1007/s00167-020-06098-y)
• [L4] Some persistent pain and osteoarthritis progression remain concerns. [4] (10.1016/j.arthro.2009.04.073)
• [L3] Clinicians should consider overreduction of the AC joint because it may lead to favorable radiological results. [5] (10.1177/0363546519862850)
• [L4] The outcomes of this study seem to suggest that a distinction between symptomatic and asymptomatic radiographic AC OA is unnecessary, as all patients were equally satisfied with the outcome. [6] (10.5397/cise.2023.00073)
• [L3] Radiographic ACJ osteoarthritis is common in patients undergoing RSA. [7] (10.1016/j.jseint.2021.11.008)
• [L5] Both open and arthroscopic resection arthroplasty techniques provide predictable pain relief for symptomatic AC osteoarthritis, though each has a unique set of potential complications that may be minimized with improved understanding of anatomy, biomechanics, and meticulous surgical technique. [8] (10.1177/0363546513485359)
• [L4] Limited distal clavicle excision of patients with AC joint osteoarthritis resistant to conservative treatment reduced pain and improved shoulder function at midterm follow-up. [9] (10.1016/j.otsr.2016.01.008)
• [L5] Anatomic techniques that address both coracoclavicular ligaments and the AC capsule are recommended to restore horizontal and vertical stability while allowing physiological rotation. [10] (10.1016/j.arthro.2019.01.038)
• [L4] The AC-DC measurement and use of the Alexander view provides the clinician with a more realistic appreciation of true AC joint displacement, especially in defining watershed cases (ie, IIIA/IIB/IV) and may better inform the decision-making process regarding management options and recommendations. [12] (10.1016/j.jse.2019.12.014)
• [L4] Additional research is needed to determine the main cause of pain and compare clinical outcomes of intra-articular versus extra-articular injections. [13] (10.5397/cise.2023.00311)
• [L4] Recurrence of the initial dislocation appears to be related to onset of degenerative ACJ arthropathy. [14] (10.1016/j.otsr.2017.11.001)
• [L4] This suggests that Type V AC dislocations may be given a trial of conservative therapy. [15] (10.1177/2325967115s00017)
• [L1] Injuries to the SC joint are uncommon, and recognition and classification are critical to proper management to minimize long-term sequelae. [16] (10.1177/0363546513498990)
• [L4] Conservative and surgical treatments are both effective in acromioclavicular joint osteoarthritis management. [17] (10.1007/s00167-020-06377-8)
• [L3] Risk factors for subsequent DCE included tenderness to palpation at the AC joint, female sex, and surgery on the dominant side, with subsequent DCE performed in 40% of cases with a combination of these 3 factors. [18] (10.1177/2325967119844295)
• [L1] Preventive arthroscopic DCR is not recommended in patients with radiological but asymptomatic ACJ arthritis. [19] (10.1177/0363546514547254)
• [L1] The arthroscopic approach offers a unique advantage in diagnosing and treating occult intra-articular pathology. [20] (10.1016/j.jse.2006.10.006)
• [L4] The authors recommend this procedure for the treatment of chronic complete AC dislocations. [21] (10.1016/j.injury.2010.09.023)
• [L4] AC injections offer a 1-year success rate of 47%. [22] (10.5397/cise.2023.00031)
• [L4] Osteoarthritis is associated with poorer final clinical outcomes, and an unhealed or re-torn cuff increases the risk of osteoarthritis. [23] (10.1016/j.otsr.2017.03.007)
• [L1] Evaluating the integrity of the capsuloligamentous structures stabilizing the AC joint is reproducible and gives additional information on the severity of the injury, which might also influence the treatment decision. [24] (10.1016/j.jse.2020.10.026)
• [L4] Treatment of ACD by synthetic ligament reconstruction gave satisfactory results, notably in terms of recovery of strength, but evolution is not risk-free with onset of significant early osteolysis. [25] (10.1016/j.otsr.2010.06.004)
• [L5] Although each technique was able to restore different elements of the joint kinematics, none of the strategies completely restored the shoulder girdle to its preinjured state. [26] (10.1177/03635465221095231)
• [L5] The kinematic changes could be a potential source of pain and dysfunction in the shoulder with AC joint dislocation. [27] (10.1177/0363546512458571)
• [L5] Scapular and clavicular kinematics were affected in AC separation models. [28] (10.1016/j.jse.2013.01.004)
• [L5] The observed frequency of hook contact with surrounding subacromial structures in a static shoulder confirms that the position of the hook portion of the implant can predispose anatomic structures to the post-operative complications of subacromial impingement and bony erosion. [29] (10.1016/j.injury.2009.12.012)
• [L4] Non-operative reduction and stabilization of high-grade AC joint separations seems to be a valuable treatment option. [33] (10.1007/s00402-020-03630-0)
• [L5] Future research should focus on addressing horizontal and rotational instability, to restore native physiological and biomechanical properties of the AC joint. [35] (10.1186/s12891-022-05935-0)
• [L1] Open and arthroscopic AC joint reconstruction techniques have no differences in loss of reduction, the complication rate, and the revision rate based on the available literature. [38] (10.1177/0363546518795147)
• [L4] Outcomes after arthroscopic CC reconstruction for chronic, type V AC dislocations in an active-duty military patient population show sustained and statistically significant improvements in functional outcomes as well as high rates of return to sport and maintenance of active-duty military status at long-term follow-up. [39] (10.1016/j.arthro.2025.05.008)
• [L1] Coracoclavicular reconstruction with augmentation of the acromioclavicular joint has been shown to provide improved horizontal stability in both biomechanical and clinical studies compared to isolated coracoclavicular reconstruction. [41] (10.1007/s00167-018-5152-7)
• [L4] Patients with edema on MRI were more likely to present pain than patients without edema, and subchondral bone edema on histologic examination was more frequent in patients with pain. [43] (10.1016/j.jseint.2020.03.007)
• [L5] Nonoperative treatment is helpful for most patients, although those with osteolysis may have to modify their activities. [44] (10.5435/00124635-199905000-00004)
• [L3] The presented data suggest adding a fixation of the AC joint to minimize lateral tilting of the scapula and maintain a more anatomic reposition result over time. [45] (10.1007/s00402-021-03761-y)
• [L4] The short-term follow-up of 15 recently operated patients reveals excellent radiologic and clinical results, with no subluxations or dislocations of the acromioclavicular joint noted. [48] (10.1016/j.arthro.2006.12.015)
• [L4] At a minimum 5-year follow-up, patients with successful non-operative treatment for type III-V ACJ injuries achieved similar clinical outcomes compared to those who were converted to ACCR. [49] (10.1007/s00167-020-06159-2)
• [L4] Surgery for AC dislocations is difficult with radiological results that must still be improved, as radiological failures were observed in 41% of cases. [50] (10.1016/j.otsr.2015.09.012)

References

[1] Outcome of distal clavicle resection in patients with acromioclavicular joint osteoarthritis and full‐thickness rotator cuff tear. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3114-2 [2] Seven-year course of asymptomatic acromioclavicular osteoarthritis diagnosed by MRI. Journal of Shoulder and Elbow Surgery. 2019. DOI: 10.1016/j.jse.2019.04.004 [3] Acromioclavicular joint arthritis is not an indication for routine distal clavicle excision in arthroscopic rotator cuff repair. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06098-y [4] The Role of Arthroscopy in Revision of Failed Open Anterior Stabilization of the Shoulder. Arthroscopy. 2009. DOI: 10.1016/j.arthro.2009.04.073 [5] Factors Predicting the Outcome After Arthroscopically Assisted Stabilization of Acute High-Grade Acromioclavicular Joint Dislocations. The American Journal of Sports Medicine. 2019. DOI: 10.1177/0363546519862850 [6] Diagnostic value of a preoperative acromioclavicular injection for symptomatic acromioclavicular osteoarthritis: a retrospective study of cross-sectional midterm outcomes. Clinics in Shoulder and Elbow. 2024. DOI: 10.5397/cise.2023.00073 [7] Severe acromioclavicular joint osteoarthritis is associated with acromial stress fractures after reverse shoulder arthroplasty. JSES International. 2022. DOI: 10.1016/j.jseint.2021.11.008 [8] Degenerative Joint Disease of the Acromioclavicular Joint. The American Journal of Sports Medicine. 2013. DOI: 10.1177/0363546513485359 [9] Limited distal clavicle excision of acromioclavicular joint osteoarthritis. Orthopaedics & Traumatology: Surgery & Research. 2016. DOI: 10.1016/j.otsr.2016.01.008 [10] Editorial Commentary: Why We Have To Respect The Anatomy In Acromioclavicular Joint Surgery And Why Clinical Shoulder Scores Might Not Give Us The Information We Need!. Arthroscopy. 2019. DOI: 10.1016/j.arthro.2019.01.038 [11] 10.1016-0020-1383-83-90092-x. n.d.. [12] Improved identification of unstable acromioclavicular joint injuries in a clinical population using the acromial center line to dorsal clavicle radiographic measurement. Journal of Shoulder and Elbow Surgery. 2020. DOI: 10.1016/j.jse.2019.12.014 [13] Isolated acromioclavicular osteoarthritis and steroid injection. Clinics in Shoulder and Elbow. 2023. DOI: 10.5397/cise.2023.00311 [14] Arthroscopically assisted reduction of acute acromioclavicular joint dislocation using a single double-button device: Medium-term clinical and radiological outcomes. Orthopaedics & Traumatology: Surgery & Research. 2018. DOI: 10.1016/j.otsr.2017.11.001 [15] Successful Conservative Therapy in Rockwood Type V Acromioclavicular Dislocations. Orthopaedic Journal of Sports Medicine. 2015. DOI: 10.1177/2325967115s00017 [16] Instability and Degenerative Arthritis of the Sternoclavicular Joint. The American Journal of Sports Medicine. 2013. DOI: 10.1177/0363546513498990 [17] No differences between conservative and surgical management of acromioclavicular joint osteoarthritis: a scoping review. Knee Surgery, Sports Traumatology, Arthroscopy. 2021. DOI: 10.1007/s00167-020-06377-8 [18] Preoperative Factors Associated With Subsequent Distal Clavicle Resection After Rotator Cuff Repair. Orthopaedic Journal of Sports Medicine. 2019. DOI: 10.1177/2325967119844295 [19] Is Arthroscopic Distal Clavicle Resection Necessary for Patients With Radiological Acromioclavicular Joint Arthritis and Rotator Cuff Tears?. The American Journal of Sports Medicine. 2014. DOI: 10.1177/0363546514547254 [20] Arthroscopic versus open distal clavicle excision: Comparative results at six months and one year from a randomized, prospective clinical trial. Journal of Shoulder and Elbow Surgery. 2007. DOI: 10.1016/j.jse.2006.10.006 [21] Surgical treatment of chronic acromioclavicular dislocation: Comparison between two surgical procedures for anatomic reconstruction. Injury. 2010. DOI: 10.1016/j.injury.2010.09.023 [22] Mid- to long-term success rate and functional outcomes of acromioclavicular injections in patients with acromioclavicular osteoarthritis. Clinics in Shoulder and Elbow. 2023. DOI: 10.5397/cise.2023.00031 [23] Osteoarthritis after rotator cuff repair: A 10-year follow-up study. Orthopaedics & Traumatology: Surgery & Research. 2017. DOI: 10.1016/j.otsr.2017.03.007 [24] The ligamentous injury pattern in acute acromioclavicular dislocations and its impact on clinical and radiographic parameters. Journal of Shoulder and Elbow Surgery. 2021. DOI: 10.1016/j.jse.2020.10.026 [25] Acute grade III and IV acromioclavicular dislocations: Outcomes and pitfalls of reconstruction procedures using a synthetic ligament. Orthopaedics & Traumatology: Surgery & Research. 2010. DOI: 10.1016/j.otsr.2010.06.004 [26] Differences between Coracoclavicular, Acromioclavicular, or Combined Reconstruction Techniques on the Kinematics of the Shoulder Girdle. The American Journal of Sports Medicine. 2022. DOI: 10.1177/03635465221095231 [27] The Function of the Acromioclavicular and Coracoclavicular Ligaments in Shoulder Motion. The American Journal of Sports Medicine. 2012. DOI: 10.1177/0363546512458571 [28] Acromioclavicular joint ligamentous system contributing to clavicular strut function: a cadaveric study. Journal of Shoulder and Elbow Surgery. 2013. DOI: 10.1016/j.jse.2013.01.004 [29] Subacromial morphometric assessment of the clavicle hook plate. Injury. 2010. DOI: 10.1016/j.injury.2009.12.012 [33] Can an acute high-grade acromioclavicular joint separation be reduced and stabilized without surgery? A surgeon’s experience. Archives of Orthopaedic and Trauma Surgery. 2020. DOI: 10.1007/s00402-020-03630-0 [35] Current concepts in acromioclavicular joint (AC) instability – a proposed treatment algorithm for acute and chronic AC-joint surgery. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05935-0 [38] Current Concepts in the Operative Management of Acromioclavicular Dislocations: A Systematic Review and Meta-analysis of Operative Techniques. The American Journal of Sports Medicine. 2018. DOI: 10.1177/0363546518795147 [39] Arthroscopic Coracoclavicular Ligament Reconstruction With Double‐Bundle Soft Tissue Allograft for Chronic Type V Acromioclavicular Dislocations Shows Excellent Patient Outcomes and Return to Duty and Sport at Minimum 10‐Year Follow‐Up. Arthroscopy. 2025. DOI: 10.1016/j.arthro.2025.05.008 [41] Acromioclavicular joint augmentation at the time of coracoclavicular ligament reconstruction fails to improve functional outcomes despite significantly improved horizontal stability. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-5152-7 [43] Histologic and magnetic resonance image evaluation in acromioclavicular joint osteoarthritis. JSES International. 2020. DOI: 10.1016/j.jseint.2020.03.007 [44] Painful Conditions of the Acromioclavicular Joint. Journal of the American Academy of Orthopaedic Surgeons. 1999. DOI: 10.5435/00124635-199905000-00004 [45] Additional acromioclavicular cerclage limits lateral tilt of the scapula in patients with arthroscopically assisted coracoclavicular ligament reconstruction. Archives of Orthopaedic and Trauma Surgery. 2021. DOI: 10.1007/s00402-021-03761-y [48] Minimally Invasive Coracoclavicular Ligament Augmentation With a Flip Button/Polydioxanone Repair for Treatment of Total Acromioclavicular Joint Dislocation. Arthroscopy. 2007. DOI: 10.1016/j.arthro.2006.12.015 [49] Conversion to anatomic coracoclavicular ligament reconstruction (ACCR) shows similar clinical outcomes compared to successful non‐operative treatment in chronic primary type III to V acromioclavicular joint injuries. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06159-2 [50] Complication rates and types of failure after arthroscopic acute acromioclavicular dislocation fixation. Prospective multicenter study of 116 cases. Orthopaedics & Traumatology: Surgery & Research. 2015. DOI: 10.1016/j.otsr.2015.09.012