Acromioclavicular Joint Lesions in Adolescents-A Systematic Review and Treatment Guidelines.

True acromioclavicular joint (ACJ) injuries are rare in children and adolescents due to the strength of ligaments in this age group. However, a standardized management guideline for these injuries is currently lacking in the literature. This systematic review aims to provide an organized overview of associated injuries and propose a management algorithm for pediatric ACJ injuries. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review was conducted. Two independent observers searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Scopus databases for ACJ injuries in children and adolescents. The extracted data were analyzed (due to the limited number of publications and inhomogeneity of data, no formal statistical analysis was conducted), and cases were categorized based on injury frequency and pattern, leading to the formulation of a treatment algorithm. The risk of bias was assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist. A total of 77 articles were identified, and 16 articles (4 case series and 12 case reports) met the inclusion criteria. This study included 37 cases in 36 patients (32 males, 4 females) with a mean age of 13 years (9-17 years). Six injury categories were described. Surgical management was performed in 27 ACJ injuries (25 open, 2 arthroscopic). Various surgical implants were used including K wires, polydioxanone sutures (PDS), screws, hook plates, suture anchors, and suture button devices. Most cases achieved good to excellent outcomes, except for one case of voluntary atraumatic dislocation of the ACJ. This systematic review provides the first comprehensive analysis of ACJ injury management in adolescents with open physis. It categorizes injury patterns and presents a treatment algorithm to enhance the understanding of these injuries. The review's findings contribute valuable insights for clinicians dealing with pediatric ACJ injuries.

Instabilities and Osteoarthritis of the Sternoclavicular Joint. / Instabilitäten und Arthrose des Sternoklavikulargelenks.

Injury to the sternoclavicular joint (SCG) is very rare, accounting for 3% of shoulder injuries and < 1% of instabilities. Consequently, both the treatment of acute instabilities and their subsequent states (chronic instabilities/SCG arthrosis) are controversial. While treatment has so far been mostly conservative, in recent years there has been a trend towards surgical therapy.Considerable violence, such as that found in traffic accidents or contact sports, can tear the extremely stable ligaments between the medial clavicle and sternum. While anterior dislocation is easier to reduce in most cases, instability remains in up to 50% of cases. In most cases, posterior instability requires rapid reduction, particularly due to the anatomical proximity to important cardio-pulmonary structures. If this succeeds, the rate of persistent instabilities is low. For chronic instability, reconstruction/augmentation of the ligament apparatus with tendon grafts in the "Figure of 8 configuration" has proven to be the standard technique in recent years.

Iatrogenic instability of the acromioclavicular joint leads to ongoing impairment of shoulder function even following secondary surgical stabilization.

PURPOSE: Iatrogenic instability of the acromioclavicular joint (ACJ) following distal clavicle excision (DCE) represents an infrequent pathology. Revision surgery to restore ACJ stability and alleviate concomitant pain is challenging due to altered anatomic relationships. The purpose of this study was to evaluate the used salvage techniques and postoperative functional and radiological outcomes in retrospectively identify patients with a painful ACJ following DCE. We hypothesized that iatrogenic instability leads to ongoing impairment of shoulder function despite secondary surgical stabilization. METHODS: 9 patients with a painful ACJ after DCE (6 men, 3 women, 43.3 ± 9.4 years) were followed up at a minimum of 36 months after revision surgery. Besides range of motion (ROM), strength and function were evaluated with validated evaluation tools including the Constant score and the DASH score (Disability of the Arm, Shoulder and Hand questionnaire), specific AC Score (SACS), Nottingham Clavicle Score (NCS), Taft score and Acromioclavicular Joint Instability Score (AJI). Additionally, postoperative X-rays were compared to the unaffected side, measuring the coracoclavicular (CC) and acromioclavicular (AC) distance. RESULTS: At follow-up survey (55.8 ± 18.8 months) all patients but one demonstrated clinical ACJ stability after arthroscopically assisted anatomical ACJ reconstruction with an autologous hamstring graft. Reconstruction techniques were dependent on the direction of instability. The functional results demonstrated moderate shoulder and ACJ scores with a Constant Score of 77.3 ± 15.4, DASH-score of 51.2 ± 23.4, SACS 32.6 ± 23.8, NCS 77.8 ± 14.2, AJI 75 ± 14.7 points and Taft Score 7.6 ± 3.4 points. All patients stated they would undergo the revision surgery again. Mean postoperative CC-distance (8.3 ± 2.8 mm) did not differ significantly from the contralateral side (8.5 ± 1.6 mm) (p > 0,05). However, the mean AC distance was significantly greater with 16.5 ± 5.8 mm compared to the contralateral side (3.5 ± 1.9 mm) (p = 0.012). CONCLUSION: Symptomatic iatrogenic ACJ instability following DCE is rare. Arthroscopically assisted revision surgery with an autologous hamstring graft improved ACJ stability in eight out of nine cases (88.9%). However, the functional scores showed ongoing impairment of shoulder function and a relatively high overall complication rate (33.3%). Therefore, this study underlines the importance of precise preoperative indication and planning and, especially, the preservation of ACJ stability when performing AC joint resection procedures. LEVEL OF EVIDENCE: Case series, LEVEL IV.

Comment on Feuerriegel et al. Assessment of Acute Lesions of the Biceps Pulley in Patients with Traumatic Shoulder Dislocation Using MR Imaging. Diagnostics 2022, 12, 2345.

We wish to congratulate the authors for the successful publication of the article titled 'Assessment of Acute Lesions of the Biceps Pulley in Patients with Traumatic Shoulder Dislocation Using MR Imaging' [...].

Biceps Brachii Alterations Following the Latarjet Procedure: A Prospective Multicenter Study.

PURPOSE: To prospectively investigate the postoperative forearm supination and elbow flexion strength of both upper extremities and popeye deformity in patients who underwent a mini-open Latarjet procedure for anterior shoulder instability. METHODS: Patients who underwent a mini-open Latarjet procedure at two specialized shoulder centers were prospectively evaluated preoperatively (T0) and at least 6 months (T1) after surgery. Subjects were tested for elbow flexion and forearm supination strength of both upper extremities using an isometric dynamometer and customized torque dynamometer. Clinical outcome was assessed by the Constant Score (CS), American Shoulder and Elbow Score (ASES) and Simple Shoulder test (SST). Popeye deformity was defined as a distalization of the greatest circumference of the biceps muscle belly towards the lateral epicondyle of the elbow. RESULTS: A total of 20 patients with a mean age of 27 ± 6 years were included in the study. At a mean follow-up of 10 ± 3 months, the elbow flexion strength was restored to the preoperative state (p = 0.240). Forearm supination strength significantly decreased at final follow-up, to 88 % in the surgical arm (p = 0.015) vs. 90 % in the non-surgical arm (p = 0.023). There was no statistical difference when comparing both arms concerning elbow flexion strength (p = 0.510) and forearm supination strength (p = 0.495). No significant popeye deformity was observed in both arms (p = 0.111 vs. p = 0.508). Clinical outcome scores improved significantly from 73 ± 18 to 82 ± 13 (p = 0.014) for CS and 76 ± 22 to 89 ± 12 (p = 0.008) for ASES score preoperatively to final follow-up. No difference in the SST was documented (p = 0.10). CONCLUSION: The Latarjet procedure showed to preserve elbow flexion strength and provided comparable forearm supination strength compared to the uninjured arm with reliable clinical outcome in this study population. However, a decrease of forearm supination strength in both arms was persistent at a mean of 10 months postoperatively. No popeye deformity was noted in the postoperative examinations. LEVEL OF EVIDENCE: Case series, Level III.

A classification for partial subscapularis tendon tears.

PURPOSE: The aim of the study was to analyze partial subscapularis tendon (SSC) tears and provide a descriptive classification. METHODS: The retrospective study included 50 patients with arthroscopically confirmed partial SSC tears. Internal rotation (IR) force measurements and IR ROM have been made and compared to the healthy contralateral side. Then the footprint of the SSC was routinely investigated by arthroscopy with standardized measurement of the bony footprint lesion. The partial tears were classified according to the mediolateral and craniocaudal extension of the rupture in the transverse and coronal plane, respectively. RESULTS: Partial SSC tears could be classified into split lesions (type 1, n = 11) and 3 further groups depending on the mediolateral peeled-off length of the bony footprint (type 2: < 10 mm, n = 20; type 3: 10-15 mm, n = 10; type 4: > 15 mm, n = 9). Type 2-4 could be further divided depending on the craniocaudal peeled-off length of the bony footprint (group A: < 10 mm, group B: 10-15 mm, group C: > 15 mm). Significantly decreased IR strength was shown for types 2-4 (p < 0.05) but not for split lesions as compared to healthy side. Types 1-4 showed significant decreased active IR ROM and all except type 3 (n.s.) which showed decreased passive IR ROM compared to the healthy side (p < 0.05). CONCLUSION: We present a novel classification for partial SSC tears for a more detailed and reproducible description. This can help to improve the current knowledge about the appropriate treatment. It could be shown that partial tears of the subscapularis can have an impact on IR strength and motion. LEVEL OF EVIDENCE: III.

Prospective midterm results of a new convertible glenoid component in anatomic shoulder arthroplasty: a cohort study.

PURPOSE: The purpose of our study was to evaluate the clinical and radiological results of a new anatomic convertible cementless glenoid component. METHODS: Forty-eight patients with a mean age of 67.3 years were clinically and radiologically followed-up with a mean of 49 months. Indications for glenoid replacement were A2 glenoid wear in 21.7%, B1 glenoid wear in 28.3%, B2 glenoid wear in 28.3%, B3 glenoid wear in 13%, D glenoid wear in 2.2%, and glenoid component loosening in 6.5%. RESULTS: The Constant-Murley score improved significantly (p < 0.0001) from 50% pre-OP to 103% post-OP. Patients with a B3 glenoid type according to Walch achieved a significant (p = 0.044) lower Constant-Murley Sscore post-OP compared to patients with a B1 glenoid type (88% vs 106%). The mean subluxation index changed significantly (p < 0.0001) from 0.54 pre-OP to 0.46 post-OP. At the metal-back bone interface an incomplete radiolucent line < 1 mm was observed in two cases (4.2%) and an incomplete radiolucent line < 2 mm was observed in another two cases (4.2%). PE dissociation occurred in two cases. No glenoid loosening was observed. The implant related revision rate was 4.2% (2 cases). All components (n = 612.5%) requiring conversion to reverse were converted without any further complications or loosening. CONCLUSION: Good functional results can be achieved in cases with a B1 and a B2 glenoid after anatomic shoulder arthroplasty using the described metal back glenoid. A conversion from an anatomic to a reverse glenoid component were possible in all cases without any further complications. Conversion of the anatomic glenoid component to a reverse system alleviates revision surgery.

High degree of consensus achieved regarding diagnosis and treatment of acromioclavicular joint instability among ESA-ESSKA members.

PURPOSE: To develop a consensus on diagnosis and treatment of acromioclavicular joint instability. METHODS: A consensus process following the modified Delphi technique was conducted. Panel members were selected among the European Shoulder Associates of ESSKA. Five rounds were performed between October 2018 and November 2019. The first round consisted of gathering questions which were then divided into blocks referring to imaging, classifications, surgical approach for acute and chronic cases, conservative treatment. Subsequent rounds consisted of condensation by means of an online questionnaire. Consensus was achieved when ≥ 66.7% of the participants agreed on one answer. Descriptive statistic was used to summarize the data. RESULTS: A consensus was reached on the following topics. Imaging: a true anteroposterior or a bilateral Zanca view are sufficient for diagnosis. 93% of the panel agreed on clinical override testing during body cross test to identify horizontal instability. The Rockwood classification, as modified by the ISAKOS statement, was deemed valid. The separation line between acute and chronic cases was set at 3 weeks. The panel agreed on arthroscopically assisted anatomic reconstruction using a suspensory device (86.2%), with no need of a biological augmentation (82.8%) in acute injuries, whereas biological reconstruction of coracoclavicular and acromioclavicular ligaments with tendon graft was suggested in chronic cases. Conservative approach and postoperative care were found similar CONCLUSION: A consensus was found on the main topics of controversy in the management of acromioclavicular joint dislocation. Each step of the diagnostic treatment algorithm was fully investigated and clarified. LEVEL OF EVIDENCE: Level V.

Off-track Hill-Sachs lesions predispose to recurrence after nonoperative management of first-time anterior shoulder dislocations.

PURPOSE: The purpose of this study was to evaluate whether the presence of an off-track Hill-Sachs lesion has an impact on the recurrence rate after nonoperative management of first-time anterior shoulder dislocations. METHODS: A retrospective cohort study was planned with a follow-up via questionnaire after a minimum of 24 months. Fifty four patients were included in the study (mean age: 29.5 years; 16 female, 38 male). All of these patients opted for primary nonoperative management after first-time traumatic anterior shoulder dislocation, in some cases even against the clinician's advice. The glenoid track and the Hill-Sachs interval were evaluated in the MRI scans. The clinical outcome was evaluated via a shoulder-specific questionnaire, ASES-Score and Constant Score. Further, patients were asked to report on recurrent dislocation (yes/no), time to recurrent dislocation, pain, feeling of instability and satisfaction with nonoperative management. RESULTS: In 7 (13%) patients, an off-track Hill-Sachs lesion was present, while in 36 (67%) the lesion was on-track and 11 (20%) did not have a structural Hill-Sachs lesion at all. In total, 31 (57%) patients suffered recurrent dislocations. In the off-track group, all shoulders dislocated again (100%), while 21 (58%) in the on-track group and 3 (27%) in the no structural Hill--Sachs lesion group had a recurrent dislocation, p = 0.008. The mean age in the group with a recurrence was 23.7 ± 10.1 years, while those patients without recurrent dislocation were 37.4 ± 13.1 years old, p < 0.01. The risk for recurrence in patients under 30 years of age was higher than in those older than 30 years (OR = 12.66, p < 0.001). There were no significant differences between patients with on- and off-track lesions regarding patients' sex, height, weight and time to reduction and glenoid diameter. Off-track patients were younger than on-track patients (24.9 ± 7.3 years vs. 29.6 ± 13.6 years). However, this difference was not statistically significant. CONCLUSION: The presence of an off-track Hill-Sachs lesion leads to significantly higher recurrence rates compared to on-track or no structural Hill--Sachs lesions in patients with nonoperative management and should be considered when choosing the right treatment option. Therefore, surgical intervention should be considered in patients with off-track Hill-Sachs lesions. LEVEL OF EVIDENCE: IV.

Lesions of the biceps pulley: a prospective study and classification update.

HYPOTHESIS: The purpose of the study was to investigate which anatomic structures are affected in a series of patients with pulley lesions and whether all lesions can be classified according to the Habermeyer classification. METHODS: One hundred consecutive patients with pulley lesions were prospectively studied. During arthroscopy, lesions of the superior glenohumeral ligament (SGHL), medial coracohumeral ligament (MCHL) and/or lateral coracohumeral ligament (LCHL), adjacent rotator cuff, and biceps (long head of the biceps) were recorded. All lesions were then classified according to the Habermeyer classification. The χ2 test was used for statistical analysis. RESULTS: There were 3 lesions in group 1, 20 in group 2, 6 in group 3, and 35 in group 4 according to the Habermeyer classification. Thirty-six lesions were not classifiable because of an intact SGHL. A lateral pulley sling (LCHL) lesion was found in 95% of the patients, and a medial pulley sling (MCHL-SGHL) lesion was noted 64%. An isolated lesion of the MCHL and/or SGHL was present in 5%, and an isolated lesion of the LCHL was found in 36%. Combined medial-lateral sling lesions were correlated with complete subscapularis tears and biceps fraying. CONCLUSION: The lateral pulley sling is more often affected than the medial sling. The SGHL is not always affected, and isolated lesions of the medial sling are rare. Lesions of both slings correlated with complete subscapularis tears and fraying of the long head of the biceps. An updated classification of direct pulley lesions is proposed: type 1, lesion of the medial pulley (MCHL and/or SGHL); type 2, lesion of the lateral pulley (LCHL); and type 3, lesion of the medial and lateral pulley slings. Concomitant lesions of the indirect pulley stabilizers can be mentioned additionally according to the well-known classifications.

The importance of biomechanical properties in revision acromioclavicular joint stabilization: a scoping review.

PURPOSE: Treatment of failed primary reconstruction of the unstable acromioclavicular (AC) joint remains challenging for orthopaedic surgeons. When approaching revision cases, the reason for failure has to be precisely identified. The purpose of this manuscript was to perform a critical review of the literature regarding treatment options for failed AC joint stabilization techniques and to provide a treatment algorithm for salvage procedures. METHODS: A thorough search included electronic databases for articles published up to April 15th, 2019. Inclusion criteria were set as (1) studies that reported on clinical outcomes following surgical or conservative treatment of AC joint dislocation; (2) studies reporting on failure or complications of primary treatment; (3) chronic instabilities caused by delayed or secondary treatment as well as (4) revision and salvage procedures. RESULTS: The search strategy identified a total of 3269 citations. The final dataset comprised 84 studies published between 1954 and 2019. A total of 5605 patients (9.63% females) were involved with a mean age of 34.5 years. Overall, complication rates varied between 5 and 88.9% in patients with AC joint instability. CONCLUSION: In the current literature, evidence for treatment of revision AC joint instability is still lacking, however, surgical treatment continues to evolve. The importance of failure analysis and clinically relevant algorithms were highlighted in this review. Adequately restoring native joint biomechanics is needed for ensuring an optimal healing environment that will translate into patient satisfaction and long-term stability. LEVEL OF EVIDENCE: V.

[Operative treatment of stiff shoulder : Arthroscopic arthrolysis, mobilization under anesthesia and postoperative management]. / Operative Therapie der "stiff shoulder" : Arthroskopische Arthrolyse, Narkosemobilisation und postoperatives Management.

The operative treatment of stiff shoulder using arthroscopically assisted arthrolysis is indicated in patients with persistent, symptomatic and therapy-resistant movement restrictions. Patients should be informed about relevant risks, supervised rehabilitation and possible recurrences. The surgical procedure provides a precise and controlled semicircular capsulotomy and is followed by an intensive rehabilitation program in order to minimize the risk of recurrences.

Arthroscopically assisted acromioclavicular joint stabilization leads to significant clavicular tunnel widening in the early post-operative period.

PURPOSE: Arthroscopically assisted acromioclavicular joint (ACJ) stabilization techniques use bone tunnels in the clavicle and coracoid process. The tunnel size has been shown to have an impact on the fracture risk of clavicle and coracoid. The aim of the present study was to radiographically evaluate the alterations of the clavicular tunnel size in the early post-operative period. It was hypothesized that there would be a significant increase of tunnel size. METHODS: Twenty consecutive patients with acute high-grade ACJ (Rockwood type IV-V) injury underwent arthroscopic-assisted ACJ stabilization. The median age of the patients was 40 (26-66) years. For all patients, a single tunnel button-tape construct was used along with an additional ACJ tape cerclage. Radiologic measurements were undertaken on standardized Zanca films at two separate time points, immediate post-operative examination (IPO) and at late post-operative examination (> 4 months; LPO). The LPO radiographs were taken at a median follow-up period of 4.5 (3-6) months. Clavicular tunnel width (CT) and coracoclavicular distance (CCD) were measured using digital calipers by two independent examiners and the results are presented as median, range, and percentage. RESULTS: The median CCD increased significantly from 9.5 (8-13) mm at IPO to 12 (7-20) mm at LPO (p < 0.05). Median tunnel size showed significant difference from 3 (3-4) mm at IPO to 5 (4-7) mm at LPO (p < 0.05). Despite a significant increase of 2 mm (66.6%) of the initial tunnel size, there was no correlation between tunnel widening and loss of reduction. CONCLUSION: Arthroscopic ACJ stabilization with the use of bone tunnels led to a significant increase of clavicular tunnel size in the early post-operative period. This phenomenon carries a higher fracture risk, especially in high-impact athletes, which needs to be considered preoperatively. LEVEL OF EVIDENCE: IV.

[Shoulder Osteoarthritis-pathogenesis, classification, diagnostics and treatment]. / Omarthrose ­ Pathogenese, Klassifikation, Diagnostik und Therapie.

Primary osteoarthritis of the shoulder represents a destructive joint disease with associated synovitis, which in the first line seems to be genetically determined. Clinically, patients suffer from shoulder pain with progressive impairment of both active and passive range of motion. The diagnostics include a clinical examination, imaging by native radiography and magnetic resonance imaging (MRI) for assessment of the rotator cuff. Current classification systems consider the formation of humeral osteophytes, glenoid morphology and loss of humeral sphericity. Non-surgical measures include, apart from topical and oral analgesics, injection of corticosteroids and hyaluronic acid supported by physiotherapeutic measures. After failure of non-surgical therapeutic measures, arthroscopic joint-preserving arthroplasty in terms of the comprehensive arthroscopic management (CAM) procedure can be performed in young patients with early stage osteoarthritis, whereas in advanced stages endoprosthetic joint replacement is indicated.

Arthroscopic Coracoclavicular and Acromioclavicular Stabilization of Acute Acromioclavicular Joint Dislocation By Suspensory Fixation System.

Arthroscopic stabilization of acute acromioclavicular joint dislocations using coracoclavicular suspension techniques has become more popular, but lack of horizontal stability is a major concern that furthermore affects the final outcome. We present an arthroscopic technique to stabilize acute acromioclavicular joint dislocations in both the vertical and horizontal planes, with better results than conventional coracoclavicular suspension techniques.

Sternoclavicular Joint Reconstruction Fracture Risk Is Reduced With Straight Drill Tunnels and Optimized With Tendon Graft Suture Augmentation.

BACKGROUND: Despite the rare entity of sternoclavicular joint (SCJ) instability, a variety of different reconstruction techniques for SCJ dislocations have been described. A technique with oblique drilling has been proposed to reduce intraoperative risks. PURPOSE: To biomechanically investigate different cerclage reconstruction techniques and the benefit of additional reinforcement using suture tape. STUDY DESIGN: Controlled laboratory study. METHODS: Reconstructed artificial bone specimens were mounted on a mechanical testing machine. They were subjected to anterior and posterior translation, analyzing ultimate strength, displacement, stiffness, and elongation. For stage 1, different angulations of the drill tunnels through the sternum and clavicle were compared. Straight drill tunnels from anterior to posterior were compared with 45° oblique drill tunnels. For stage 2, three different materials for cerclage reconstruction were compared: (1) suture tape alone (FT group), (2) tendon graft alone (tendon group), and (3) tendon graft with suture tape augmentation (tendon+FT group). RESULTS: For the FT group, in the anterior and posterior directions, straight drill holes resulted in a significantly higher load to failure (936.9 ± 122.5 N) compared with oblique ones (434.5 ± 20.2 N) (P < .0001). During cyclic testing, all specimens with straight drill holes survived the 5- to 550-N step, while all specimens with oblique ones failed during the 5- to 450-N step. Analyzing the graft material choice, the mean load to failure was 556.6 ± 174.3 N for the tendon group, 936.9 ± 122.5 N for the FT group, and 767.0 ± 110.7 N for the tendon+FT group (P = .089). The stiffness of the tendon+FT group was significantly lower than that of the FT group and significantly higher than that of the tendon group. CONCLUSION: Oblique tunnel placement during SCJ reconstruction, while reducing the intraoperative risk, results in decreased primary stability of the construct. Tendon graft reconstruction with suture tape augmentation leads to enhanced stability and optimizes biomechanical properties of the construct. CLINICAL RELEVANCE: The surgical technique with straight drill holes has superior initial biomechanical properties and may likewise produce superior clinical outcomes in the treatment of SCJ instability. Suture tape augmentation can provide additional stability to reconstruction procedures.

The Diagnosis and Treatment of Acute Dislocation of the Acromioclavicular Joint.

BACKGROUND: The acromioclavicular joint (ACJ) is one of the more common sites of shoulder girdle injury, accounting for 4-12% of all such injuries, with an incidence of 3-4 cases per 100 000 persons per year in the general population. Current topics of debate include the proper standard diagnostic evaluation, the indications for surgery, and the best operative method. METHODS: This review is based on publications retrieved by a selective literature search. RESULTS: Mechanical trauma of the ACG can tear the ligamentous apparatus that holds the acromion, clavicle, and coracoid process together. Different interventions are indicated depending on the nature of the injury. In recent years, the horizontal component of the instability has received more attention, in addition to its vertical component. Persistent instability can lead to chronic, painful limitation of shoulder function, particularly with respect to working above the head. Surgical stabilization is therefore recommended for high-grade instability of Rockwood types IV and V. Modern reconstruction techniques enable selective vertical and horizontal treatment of the instability and have been found superior to traditional methods, particularly in young athletes. Arthroscopic techniques are advantageous because they are less invasive, do not require removal of implanted material, and afford the opportunity to diagnose any accompanying lesions definitively and to treat them if necessary. Surgery for acute injuries should be performed within three weeks of the trauma. For chronic injuries, additional tendon augmentation is now considered standard treatment. CONCLUSION: High-grade ACJ instability is a complex and significant injury of the shoulder girdle that can cause persistent pain and functional impairment. The state of the evidence regarding its optimal treatment is weak. Large-scale, prospective, randomized comparative studies are needed in order to define a clear standard of treatment.

Clavicle and coracoid process periprosthetic fractures as late post-operative complications in arthroscopically assisted acromioclavicular joint stabilization.

PURPOSE: Arthroscopic-assisted stabilization surgery for acute acromioclavicular joint (ACJ) disruption shows excellent and reliable clinical outcomes. However, characteristic complications such as fracture of the clavicle and coracoid have been reported to occur during the early post-operative period. The main goal of this study was to highlight the occurrence of fractures as a late post-operative complication. The secondary goals were to describe possible fracture morphologies and treatment outcomes. METHOD: Patient records from a single surgery centre were searched for all patients presenting with late fracture complication following arthroscopically assisted acromioclavicular stabilization. Medical reports including the operative notes and pre- and post-operative X-rays were reviewed. A telephone interview was conducted with each patient to access the American Shoulder and Elbow Surgeons shoulder score. RESULTS: A total of four patients presented with late fracture complication following arthroscopic-assisted ACJ stabilization surgery. All patients were males and presented following trauma at a median duration of 19.5 months after the index surgery. Fracture morphology differed between patients; the treatment was conservative in three patients, while one patient underwent osteosynthesis. CONCLUSION: Traumatic peri-implant fractures can occur, even 2 years after arthroscopically assisted ACJ reconstruction. This needs to be considered when planning for surgical intervention in acute ACJ disruption, especially in a high-risk population. LEVEL OF EVIDENCE: Therapeutic study, Level IV.