Surgical Management of Acromioclavicular Dislocations

Acromioclavicular Joint Injuries in Sport

ABSTRACT

Sport-related shoulder injuries, including disruptions to the acromioclavicular joint (ACJ), are common. An ACJ injury is classified by the degree and direction of the clavicle displacement. Although the diagnosis can be made clinically, standard radiographic views are important to determine the severity of the ACJ disruption and assess for concurrent injuries. The majority of ACJ injuries can be managed nonoperatively; however, surgical treatment is indicated in some cases. Long-term outcomes are generally favorable for most ACJ injuries, and athletes generally return to sport without functional limitations. This article provides an in-depth discussion regarding all aspects of ACJ injuries, including clinically relevant anatomy, biomechanics, evaluation, treatment, and complications.

Acromioclavicular reconstruction techniques after acromioclavicular joint injuries: A systematic review of biomechanical studies

BACKGROUND

Residual horizontal instability after surgical treatment for acromioclavicular joint injuries is seen as a potential cause of suboptimal clinical outcomes. Biomechanical studies have demonstrated that the acromioclavicular capsule/ligaments are the primary restraints for anteroposterior translation. However, limited studies have addressed the biomechanics of a reconstruction of the acromioclavicular capsule/ligaments. The aim of this systematic review was to evaluate the biomechanical role of acromioclavicular capsule/ligament reconstruction techniques after an acromioclavicular joint injury.

METHODS

A search was carried out on the databases Medline and EMBASE, and was conducted according to the PRISMA guidelines. Biomechanical studies addressing horizontal and vertical displacement or joint stiffness after reconstructing the acromioclavicular capsule/ligament with or without coracoclavicular ligament reconstruction, were included.

FINDINGS

Nineteen studies were included in this review after screening and eligibility assessment. Five of them investigated different sole acromioclavicular capsule/ligament reconstruction techniques. In 10 studies, a sole coracoclavicular ligament reconstruction was compared to a coracoclavicular ligament reconstruction with additional acromioclavicular capsule/ligament reconstruction. The remaining 4 studies compared different acromioclavicular capsule/ligament with coracoclavicular reconstruction techniques with each other.

INTERPRETATION

Several testing protocols to evaluate acromioclavicular capsule/ligament reconstruction have been described and can make it difficult to compare the results of the different studies. Acromioclavicular capsule/ligament reconstruction may provide increased anteroposterior and rotational stability but an optimal reconstruction technique, which mimics all biomechanical characteristics of the native joint is not yet available.

Surgical Management of Acute Rockwood Grade III Acromioclavicular Joint Dislocations: A Systematic Review

Injuries of the acromioclavicular joint (ACJ) occur frequently in young and active people. The best management of acute grade III injuries has been a source of controversy and extensive debate. When surgery is indicated, there is still no gold standard surgical technique for treating acute grade III ACJ injuries. The methodology of this review was a comprehensive search of PubMed, Medline, Cochrane, and EMBASE databases using various combinations of the keywords "Rockwood," "type III," "grade III," "treatment," "surgery," "acromioclavicular joint," and "dislocation," since the inception of the databases to December 2020. Surgical techniques were divided into two groups. In group 1 were ACJ fixation techniques using hardware such as the hook plate, Kirschner wires, and wire cerclage; group 2 included coracoclavicular (CC) ligament fixation/reconstruction techniques using double buttons, TightRope®, suture anchors, Endobuttons, the Infinity-LockTM Button System, etc. Fourteen studies were selected for the final review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review showed better outcome scores in group 2. Overall, complication rates were higher in group 1 compared to group 2. The results of this review show that CC fixation, using suspensory or loop devices, of Rockwood grade III injuries, has better outcomes and fewer complications than fixation of the ACJ with hardware.

Better Radiographic Reduction and Lower Complication Rates With Combined Coracoclavicular and Acromioclavicular Ligament Reconstruction Than With Isolated Coracoclavicular Reconstruction

PURPOSE

To determine whether combined acromioclavicular (AC) ligament reconstruction and coracoclavicular (CC) ligament reconstruction without bone tunnels would improve radiographic reduction maintenance and complication rates for type III to V AC dislocations.

METHODS

This single-institution retrospective study analyzed all patients who underwent a hybrid synthetic/graft wrap CC reconstruction without tunnels with additional AC reconstruction/repair from January 2013 to August 2019. This 26-patient cohort was compared with a 1:1 sex- and age-matched control group who underwent CC reconstruction without AC reconstruction. CC distances on postoperative radiographs were compared with normal contralateral shoulders.

RESULTS

Of the 93 patients who underwent AC reconstructive surgery during this time period, 26 patients (96% male) met the inclusion criteria. The AC/CC cohort had 23.5% type III injuries, 23.1% type IV injuries, and 53.8% type V injuries, similar to the control group. Final radiographs of the operative shoulder's CC distance were (mean ± standard deviation) 0.9 ± 4.0 mm greater than that of the contralateral shoulder (9.6 ± 8.7 mm) in the AC/CC cohort. Final radiographs of the operative shoulder's coracoclavicular distance were 4.0 ± 4.7 mm greater than that of the contralateral shoulder (13.3 ± 9.3 mm) in the CC control group, a significant difference (P = .014). The AC/CC reconstruction group had fewer patients with a loss of reduction >5 mm (11.5% versus 38.5%, P = .025). The complication rate in the CC control group was higher than in the AC/CC cohort (30.7% versus 7.7%, P = .035). The reoperation rate was also greater in the CC control group (8 versus 1, P = .010).

CONCLUSION

This cohort study shows that the addition of AC reconstruction to CC reconstruction using synthetic tapes/grafts or allograft tissues without bone tunnels significantly improves durable radiographic outcomes, diminishes complication rates, and improves reoperation rates.

LEVEL OF EVIDENCE

III, retrospective comparative study.

The Infinity-Lock System for Chronic Grade III AC Joint Dislocation: A Novel Technique, Rehabilitation Protocol and Short Term Results

Background: the choice of treatment of chronic grade III acromioclavicular (AC) joint dislocation is controversial. Several surgical techniques have been described in the literature, responding differently to nonoperative treatment. The aim of this study is to describe a modified technique of stabilizing an AC joint dislocation with the new Infinity-Lock Button System, in order to demonstrate that it is effective in optimizing outcomes and decreasing complications. Methods: this is a retrospective study of 15 patients who underwent surgical stabilization of the AC joint dislocation between 2018 and 2019, through modified surgical technique using the Infinity-Lock Button System. Active range of motion (ROM), Specific Acromio Clavicular Score (SACS) and Constant Score (CS) were evaluated preoperatively and postoperatively at last 18 months follow up. Patients rated their outcomes as very good, good, satisfactory, or unsatisfactory. Results: a total of twelve patients rated their outcome as very good and three as good; no patients were dissatisfied with surgery. The mean Constant Score increased from 38 points preoperatively to 95 postoperatively, the average SACS score decreased from 52 points preoperatively to 10 postoperatively, both significantly. No complications were detected. Conclusion: the described technique is effective for treatment of chronic grade III AC joint dislocation, resulting in elevated satisfaction ratings and predictable outcomes. Nevertheless, further longer term follow-up studies are required.

Synthetic coracoclavicular ligament vs. coracoclavicular suspensory construct for treatment of acromioclavicular dislocation: a biomechanical study

BACKGROUND

A synthetic ligament (LockDown, Worcestershire, England) has become available to treat complete acromioclavicular dislocation with promising clinical results and potential benefit to avoid postoperative loss of reduction. We investigated the biomechanics of this synthetic ligament in a simulated immediate postoperative rehabilitation setting, hypothesizing that the synthetic ligament would demonstrate less superior coracoclavicular displacement to cyclic loading and higher ultimate load-to-failure values than a coracoclavicular suspensory construct.

METHODS

Seven matched-pair cadaveric shoulders (mean age at time of death, 79 years) were loaded cyclically and to failure. One specimen in each pair was randomly assigned to the synthetic ligament or coracoclavicular suspensory construct. Superiorly directed 70-N cyclic loading for 3000 cycles at 1.0 Hz was applied through the clavicle in a fixed scapula simulating physiologic states during immediate postoperative rehabilitation, followed by a load-to-failure test at 120 mm/min.

RESULTS

After 3000 cycles, the superior displacement of the clavicle in the synthetic ligament (9.2 ± 1.1 mm) was 225% greater than in the coracoclavicular suspensory construct (2.8 ± 0.4 mm, 95% confidence interval [CI] 3.4, 8.3; P < .001). Average stiffness of the synthetic ligament (32.8 N/mm) was 60% lower than that of the coracoclavicular suspensory construct (81.9 N/mm, 95% CI 43.3, 54.9; P < .001). Ultimate load-to-failure of the synthetic ligament was 23% (95% CI 37.9, 301.5; P = .016) lower than the coracoclavicular suspensory construct (580.5 ± 85.1 N and 750.2 ± 135.5 N, respectively).

CONCLUSION

In a simulated immediate postoperative cadaveric model, the synthetic ligament demonstrated poorer biomechanics than the coracoclavicular suspensory construct. These findings suggest that a coracoclavicular suspensory construct may be preferable to a synthetic ligament if early rehabilitation is intended.

Surgical treatment of acute Rockwood III acromioclavicular dislocations-Comparative study between two flip-button techniques

Acromioclavicular joint dislocation is a common shoulder injury, usually caused by direct violence on the shoulder. Optimal treatment of type III is still a hot discussion currently in orthopedic surgeons. With the advent of many flip-button techniques, Tightrope system and Endobutton system become popular techniques for reconstruction of coracoclavicular ligaments. The purpose of the study was to compare the clinical and radiological results between the two techniques. A retrospective case-control study was conducted in 60 patients with acute Rockwood III acromioclavicular joint dislocation. The two techniques conducted were open procedures using Twin Tail Tightrope system (Group A, n = 30) and Endobutton system (Group B, n = 30). 60 patients were followed up at least two years. Surgical parameters including incision length, operation time and operative blood loss were analyzed. Functional outcomes were evaluated using the Constant-Murley Score. Radiological results were assessed based on coracoclavicular distance preoperatively, one day postoperatively, and at the final follow-up. 60 patients were followed up for at least 24 months (range 24 to 32). The incision length and operation time were shorter in Group A than that in Group B. The blood loss of surgery was significantly less in the Group A. There were no significant differences between the two groups regarding the Constant-Murley Score at the final follow-up. No significant differences were found in the coracoclavicular distance preoperatively, immediately postoperatively, and at the final follow-up. Both techniques offered satisfying functional outcomes, however the Tightrope system provided better surgical parameters.

The Specific AC Score (SACS): a new and validated method of assessment of isolated acromioclavicular joint pathology

BACKGROUND

Acromioclavicular (AC) joint (ACJ) pathology is a common cause of shoulder dysfunction, and treatment recommendations vary. When the efficacy of treatment is evaluated, the ability to measure outcomes specific to the population is essential. The aim of the current research was to develop and validate a specific ACJ questionnaire.

METHODS

Items for the "Specific AC Score" (SACS) were generated through the use of an expert panel, existing questionnaires, and patient feedback. Preliminary data analysis identified redundancy of items resulting in the questionnaire being refined. The final SACS was evaluated in 125 patients requiring surgical intervention of the ACJ. Internal consistency (the Cronbach α and corrected item-total correlation), content validity, criterion validity, responsiveness, and test-retest reliability (intraclass correlation coefficient) were examined and compared with the Shoulder Pain and Disability Index, Oxford Shoulder Score, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form. The minimum detectable change score was calculated.

RESULTS

The Cronbach α for the total scale preoperatively and postoperatively was high (preoperatively = 0.91, postoperatively = 0.93). All 3 domains (Pain, Function, Quality of Life) demonstrated acceptable internal consistency (α > 0.70), and the correlation between items in each domain was satisfactory. The responsiveness was excellent (effect size, -2.32; standard response mean, -1.85) and was higher than the other general shoulder questionnaires. There were no relevant floor or ceiling effects. Reliability was high (intraclass correlation coefficient, 0.89) and the minimum detectable change was 6.5 points.

DISCUSSION

This new ACJ-specific questionnaire has been robustly developed, has good measurement properties, and has excellent responsiveness. The SACS is recommended for measuring outcomes in ACJ patients.

Editorial Commentary: Double Bundle the Coracoclavicular Ligaments for Success: The More the Better?

Injuries to the acromioclavicular joint are common across all levels of sport and activity. Overall, a consensus exists regarding Rockwood grade I and II injuries (conservative approach) and Rockwood grades IV to VI (best treated surgically). However, grade III injuries are heterogeneous and thus respond differently to nonoperative and operative treatment. Regardless of the acromioclavicular injury grade, these are widely prevalent injuries, and there is a lack a consensus as to which operative fixation methods yield the best outcomes for patients. Although K-wires and plates were historically used to achieve rigid fixation, recent evidence supports the use of soft tissue grafts to reconstruct the coracoclavicular ligaments and restore vertical and anteroposterior and rotational stability with a more biological approach.

Challenges in Treating Acromioclavicular Separations: Current Concepts

Injuries to the acromioclavicular joint constitute approximately 3.2% of shoulder injuries. Although the overall goal of treatment continues to be return to activity with a pain-free shoulder, the treatment of acromioclavicular joint separations has been fraught with conflict since the earliest reports in both ancient and modern literature. Accurate diagnosis and classification are important to determine the optimal treatment. Nonsurgical therapy remains the mainstay for treatment of low- and most mid-grade injuries, although recent biomechanical and biokinetic data might suggest that patients are more affected than traditionally thought. High-grade injuries often necessitate surgical intervention, although little consensus exists on the timing or technique. New surgical techniques continue to evolve as more biomechanical data emerge and kinematic understanding improves. Challenges associated with management of this injury abound from diagnosis to reconstruction.

Stabilization of Acute High-Grade Acromioclavicular Joint Separation: A Prospective Assessment of the Clavicular Hook Plate Versus the Double Double-Button Suture Procedure

BACKGROUND

The stabilization strategy for acute high-grade acromioclavicular (AC) joint separations with AC-stabilizing clavicular hook plate (cHP) or coracoclavicular (CC)-stabilizing double double-button suture (dDBS) is still under consideration.

HYPOTHESIS

The CC-stabilizing dDBS is superior to the cHP according to an AC-specific radiologic assessment and score system.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Seventy-three consecutive patients with acute high-grade AC joint separation were prospectively followed in 2 treatment groups (64.4% randomized, 35.6% patient-selected treatment): open reduction and cHP (cHP group) or arthroscopically assisted dDBS (dDBS group) performed within 14 days of injury. Patients were prospectively analyzed by clinical scores (Taft, Constant score [CS], numeric analog scale for pain) and AC-specific radiographs (AC distance, CC distance [CCD], relative CCD [rCCD; 100 / AC distance × CCD]) at points of examination (preoperative and 6, 12, and 24 months). The minimal clinically important differences (MCIDs) were assessed by the anchor-based method.

RESULTS

Twenty-seven of 35 patients (mean age ± SD: 37.7 ± 9.7 years) after cHP implantation and 29 of 38 patients (34.2 ± 9.7 years) after dDBS implantation were continuously followed until the 24-month follow-up. All patients showed significantly increased scores after surgery as compared with preoperative status (all P < .05). As compared with GI, GII had significantly better outcomes at 24 months (Taft: cHP = 9.4 ± 1.7 vs dDBS = 10.9 ± 1.1, P < .05, MCID = 2.9; CS: cHP = 90.2 ± 7.8 vs dDBS = 95.3 ± 4.4, P < .02, MCID = 16.6) and at 24 months for Rockwood IV/V (Taft: cHP = 9.4 ± 1.7 vs dDBS = 11.1 ± 0.8, P < .0005; CS: cHP = 90.1 ± 7.7 vs dDBS = 95.5 ± 3.1, P < .04). Clinically assessed horizontal instability persisted in 18.52% (GI) and 6.89% (GII; P = .24). The rCCD showed equal loss of reduction at 24 months (GII = 130.7% [control = 111%] vs GI = 141.8% [control = 115%], MCID = 11.1%).

CONCLUSION

This prospective study showed significantly superior outcomes in all clinical scores between GII and GI. The subanalysis of the high-grade injury type (Rockwood IV/V) revealed that these patients showed significant benefits from the dDBS procedure in the clinical assessments. The cHP procedure resulted in good to excellent clinical outcome data and displayed an alternative procedure for patients needing less restrictive rehabilitation protocols.

Acromioclavicular joint injuries: diagnosis, classification and ligamentoplasty procedures

Acromioclavicular (AC) joint injury is a frequent diagnosis after an acute shoulder trauma – often found among athletes and people involved in contact sports.

This injury occurs five times more frequently in men than in women, with the highest incidence in the 20- to 30-year-old age group. Patients usually complain of pain and tenderness over the shoulder, particularly over the AC joint.

Depending on the degree of injury, the clavicle may become prominent on the injured site.

The original classification was described by Rockwood and Green according to the injured ligament complex and degree and direction of clavicular displacement.

Many surgical procedures have been described; among these are screws, plates, muscle transfer, ligamentoplasty procedures and ligament reconstruction using either autograft or allografts.

With the advancement of shoulder arthroscopy, surgeons are much more capable of performing mini-open or arthroscopically-assisted procedures, allowing patients an earlier return to their daily living activities. However, the results of conventional open techniques are still comparable.

The introduction of new arthroscopic equipment provides a great variety of surgical procedures, though every new technique has its own advantages and pitfalls. Currently there is no gold standard for the surgical treatment of any type of AC injury, though it should be remembered that whenever an arthroscopic technique is chosen, the surgeon’s expertise is likely to be the most significant factor affecting outcome.

Cite this article: EFORT Open Rev 2018;3:426-433. DOI: 10.1302/2058-5241.3.170027

Acromioclavicular and Coracoclavicular Ligament Reconstruction for Acromioclavicular Joint Instability: A Systematic Review of Clinical and Radiographic Outcomes

PURPOSE

To perform a systematic review of the available literature on clinical and radiographic outcomes after surgical treatment for acromioclavicular (AC) joint instability.

METHODS

A systematic review was performed according to PRISMA guidelines. Inclusion criteria were AC joint and coracoclavicular (CC) ligament reconstruction outcomes, English language, human studies, more than 10 patients in the study and a 2-year minimum follow-up. Exclusion criteria were animal studies, cadaveric studies, clinical studies without reported follow-up period or patient-reported outcomes, clinical studies of nonoperative treatment, AC reconstructions with concurrent lateral clavicle fracture, editorial articles, abstracts, presentations, reviews, case reports, and surveys.

RESULTS

The systematic review identified 34 studies (939 patients) after inclusion and exclusion criteria application. Postoperative American Shoulder and Elbow Surgeons (ASES) scores ranged from 93.8 to 96, 81.8 to 97.8, and 88.1 for free tendon graft, suspensory devices, and modified Weaver-Dunn techniques, respectively. Postoperative Constant scores were 76.4 to 96.0, 82.6 to 97.8, 85.9 to 97.0, 81 to 96 and 83.0 to 94.6 for free tendon graft, suspensory devices, synthetic ligament devices, modified Weaver-Dunn, and hook plate/K-wires techniques, respectively. All treatment modalities improved patient outcomes; however, hook plates and K-wires had the highest rate of complications (26.3%). Unplanned reoperation rates were 1.2%, 2.8%, 0.9%, 5.4%, and 2.6% in free tendon graft, suspensory devices, synthetic ligament devices, modified Weaver-Dunn, and hook plate/K-wires techniques, respectively.

CONCLUSIONS

Comparable subjective outcomes after surgical treatment of AC joint instability was reported for all modalities, with relatively low unplanned reoperation rates. Treatment with hook plate/K-wires was associated with the highest complication rates, and modified Weaver-Dunn had the highest unplanned reoperation rates. LEVEL OF EVIDENCE: Level IV, systematic review of Level I-IV studies.

Functional and Radiographic Outcomes After Allograft Anatomic Coracoclavicular Ligament Reconstruction

OBJECTIVES

To analyze the functional and radiographic outcomes of anatomic coracoclavicular ligament reconstruction (ACCR) using allograft tendon without interference screw fixation.

DESIGN

Retrospective nonrandomized study.

SETTING

Level I trauma center (University Hospital).

PATIENTS

Seventeen patients (mean age of 44 years) with Rockwood III through V acromioclavicular joint disruptions. Twelve of 17 patients had a primary reconstruction, including 4 patients sustaining their injuries as part of a polytrauma incident. Five of 17 patients were revisions of a previously failed acromioclavicular reconstruction procedure.

INTERVENTION

Open ACCR using hamstring allograft with high-strength suture augmentation and knotted graft fixation without interference screws.

MAIN OUTCOME MEASURES

Clinical and patient reported outcome measures including Simple Shoulder Test, American Shoulder and Elbow Surgeons scores, and visual analog scale scores for pain and radiographic outcomes.

RESULTS

The average final postoperative Simple Shoulder Test and American Shoulder and Elbow Surgeons scores were 10.8 and 80.5, respectively. The average final postoperative visual analog scale pain was 1.8. All patients demonstrated clavicle tunnel widening on final postoperative radiographs compared with immediate postoperative radiographs. The overall complication rate was 36%, with no clavicle or coracoid fractures.

CONCLUSIONS

Open ACCR using hamstring allograft tendon secured with a square knot and high-strength suture augmentation yields equivalent outcomes to those repairs requiring an additional interference screw. Clavicle tunnel widening predictably occurs, but the clinical significance is undetermined. It appears therefore that an interference screw is not needed. Larger comparison studies are needed.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Functional Outcomes of Type V Acromioclavicular Injuries With Nonsurgical Treatment

INTRODUCTION

This study investigated nonsurgical management of type V acromioclavicular (AC) injuries to determine functional outcomes and to attempt to identify factors associated with positive results.

METHODS

In a retrospective chart review, patients with radiographic and clinical evidence of type V AC injuries per the Rockwood classification were included in the study. Patients treated nonsurgically for ≥6 months were considered eligible for analysis. Functional outcomes were assessed using Disabilities of the Arm, Shoulder, and Hand (DASH) and American Shoulder and Elbow Surgeons (ASES) scores.

RESULTS

Twenty-two patients with a mean age of 42.2 ± 12.8 years were included in the study. The average coracoclavicular distance at the time of presentation was 26.3 mm (+199%). Mean DASH and ASES scores were 27.8 ± 17.7 and 62.8 ± 17.1, respectively, at an average of 34 months from the time of injury. Patients with normal DASH (≤10) and ASES (>92) scores were younger than those with abnormal scores. At final assessment, 77% of the patients were currently working, with nine patients performing manual labor.

CONCLUSION

Following nonsurgical management of type V AC injuries, most patients are able to return to work but have limited functional outcome scores. A small subset of patients with type V AC injuries can achieve normal functional outcomes with nonsurgical management.

LEVEL OF EVIDENCE

Level IV, Case Series.

Medialized Clavicular Bone Tunnel Position Predicts Failure After Anatomic Coracoclavicular Ligament Reconstruction in Young, Active Male Patients

BACKGROUND

Recent radiographic data have suggested that medialized conoid tunnel placement greater than 25% of absolute clavicular length is correlated with early failure after anatomic coracoclavicular ligament reconstructions. A comparison with a larger active duty military cohort of clinical and radiographic outcomes can serve as a basis for standardizing surgical technique.

PURPOSE

To establish the ideal radiographic tunnel position for anatomic coracoclavicular ligament reconstruction and to elucidate variables associated with early loss of reduction and ability to return to active-duty military service.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review of the military's electronic medical record between the years 2000 and 2013 was performed. All anatomic coracoclavicular reconstructions at a single institution were included for analysis, and nonanatomic or revision reconstructions were excluded. Radiographic failure was defined as 6 mm of superior clavicle displacement on immediate postoperative films.

RESULTS

A cohort of 38 patients underwent 39 anatomic coracoclavicular reconstructions. Average follow-up time was 26 months (range, 1.2-92 months). A total of 20 radiographic failures were identified, with an average conoid tunnel ratio of 0.27. When conoid tunnel ratios were compared with a reference ratio of 0.20 to 0.25, increased risk of failure was statistically significant with lateralization greater than 0.20 (P = .018; odds ratio [OR] = 40 [95% CI, 1.05-999.06]) or with medialization of 0.251 to 0.30 (P = .002; OR = 39 [95% CI, 1.58-944.36]) or greater than 0.30 (P = .029; OR = 21 [95% CI, 0.77-562.15]). Medialization of the trapezoid position greater than 0.16 (vs a range of 0.13-0.16) was also found to be significant for failure (P < .023; OR = 8 [95% CI, 1.33-48.18]). However, these significant findings did not correlate with symptoms or ability to return to duty (P > .05).

CONCLUSION

The optimal technique for treating acromioclavicular separations has yet to be determined. Recently, anatomic coracoclavicular reconstruction has demonstrated biomechanical superiority to previously described methods. The findings of optimal tunnel positioning in anatomic reconstructions from this large active-duty military cohort can assist preoperative planning to reduce failure rates when treating these difficult injuries.