Arthroscopic distal clavicle resection: a comparison of bursal and direct approaches

A systematic review of the treatment of primary acromioclavicular joint osteoarthritis

Background

This systematic review aims to comprehensively summarise and present the available evidence for the treatment of primary acromioclavicular joint (ACJ) osteoarthritis (OA).

Methods

Five databases were searched for studies investigating the management of ACJ OA. Included were studies with participants with clinical/radiological signs of primary ACJ OA, an intervention and included a functional outcome measure.

Results

Forty-eight studies were included. Treatments consisted of physiotherapy (n = 1 study), medical only (n = 11) and operative management (n = 36). Operative studies included five comparative trials - physiotherapy versus surgery (n = 1) and open versus arthroscopic resection (n = 4). A total of 1902 shoulders were treated for ACJ OA, mean age (51 years), 58% male and mean follow-up (28.5 months). Treatment with injection showed a mean improvement of 50% in pain levels at follow-up (mean = 7.5 months). The commonest surgical procedure was arthroscopic excision of the distal clavicle and operative studies averaged 6 months of conservative management and a mean functional outcome of 87.8%.

Conclusion

Studies varied in indication, intervention and quality but it did not provide evidence that both non-operative and operative interventions are effective. There was no significant difference between open or arthroscopic distal clavicle excision (DCE). Participants having between 0.5 and 2 cm of clavicle excised had good outcomes and those requiring concomitant shoulder procedures had similarly good outcomes.

Bony Regrowth and New Spur Formation as Possible Causes of Failed Distal Clavicle Excision-Mid-Term Outcomes after Revision Surgery in a Matched-Pair Analysis

BACKGROUND

Despite high rates of successful outcomes after open and arthroscopic distal clavicle excision (DCE) for symptomatic acromioclavicular joint (ACJ) degeneration, some patients present with persistent symptoms and disabilities after surgical intervention. This study aims to compare radiological, functional, and subjective outcomes of open revision surgery after failed arthroscopic DCE to primary successful arthroscopic DCE.

METHODS

In this retrospective case-control study, 10 patients who underwent open DCE revision were age- and gender-matched with 10 patients who did not require revision surgery after DCE. Radiographic evaluation included presence of acromioclavicular spurs and acromioclavicular joint distance. Functional and subjective outcomes were assessed using the CS, SSV, SST, VAS for pain, patient's satisfaction, ASES and quick DASH score.

RESULTS

At the latest postoperative follow-up (case: 57.3 ± 19.2 months; control: 63.5 ± 16.3 months), spur formation was detected in twice as many cases in the revision group, while acromioclavicular distance showed no significant difference. However, a significant bony regrowth was noticed in the revision group between revision surgery and latest follow-up, with a decrease of the acromioclavicular distance from 9.2 ± 1.6 mm to 5.9 ± 4.6 mm (p = 0.026) and a development of new spur formations in 30% of cases. There were no significant differences in overall CS between the revision and control group (p = 0.174) at final follow-up, but the control group scored significantly higher in the CS subgroups pain (p = 0.012) and internal rotation (p = 0.016). Mean SSV was significantly lower in the revision (65.5 ± 22.3%) compared to the control group (85.9 ± 16.4%; p = 0.031).

CONCLUSIONS

Bony regrowth at the distal clavicle presenting as postoperative AC-distance narrowing and new spur formation was observed more distinctly in the revision group. Despite a slight increase in postoperative outcomes after revision surgery, subjective satisfaction and recalcitrant pain remain a concern.

LEVEL OF EVIDENCE

Therapeutic Level III, retrospective case-control study.

Ligament Reconstruction and Interposition Arthroplasty of the Acromioclavicular Joint

Distal clavicle excision (DCE) for acromioclavicular (AC) joint primary osteoarthritis and post-traumatic arthritis has been shown to have good to excellent outcomes. However, there are studies that report significant rates of residual AC joint pain and distal clavicle instability after open and arthroscopic techniques. We describe a surgical technique for management of AC joint primary osteoarthritis, post-traumatic arthritis, and revision DCE that involves DCE with ligament reconstruction and tendon interposition arthroplasty. It provides distal clavicle stability and can theoretically reduce residual AC joint pain secondary to acromial abutment after DCE.

No differences between conservative and surgical management of acromioclavicular joint osteoarthritis: a scoping review

PURPOSE

To conduct a scoping review to clarify the management of acromioclavicular joint osteoarthritis, as well as to identify any existing gaps in the current knowledge.

METHODS

Studies were identified by electronic databases (Ovid, Pubmed) from their inception up to April 2nd, 2020. All studies reporting functional outcomes after conservative or surgical treatment of acromioclavicular joint osteoarthritis, either primary or secondary to trauma or distal clavicle osteolysis, were included. Following data were extracted: authors, year of publication, study design (prospective or retrospective), LOE, number of shoulders treated conservatively or surgically, patients' age, OA classification, type of conservative treatment, surgical approach, surgical technique, functional outcomes, complications, revisions, and length of follow-up. Descriptive statistics was used. Quality appraisal was assessed through the Cochrane risk of bias tool for LOE I/II studies, while the MINORS checklist was used for LOE III/IV studies.

RESULTS

Nineteen studies were included for a total of 861 shoulders. Mean age of participants was 48.5 ± 7.4 years. Mean follow-up was 43.8 ± 29.9 months. Four studies reported functional results after conservative treatment, whereas 15 studies were focused on surgical management. No studies directly compared conservative and surgical treatment. Seven studies reported a surgical approach after failure of previous conservative treatment. All studies reported functional improvement and pain relief. Complication rate was low. Overall methodological quality of included studies was very low.

CONCLUSION

Conservative and surgical treatments are both effective in acromioclavicular joint osteoarthritis management. However, available data did not allow to establish the superiority of one technique over another.

LEVEL OF EVIDENCE

Level IV.

Distal Clavicle Excision for Acromioclavicular Joint Osteoarthritis Using a Fluoroscopic Kirschner Wire Guide

Pathology of the acromioclavicular joint is common and often resistant to conservative treatment, requiring distal clavicle excision for definitive relief. First described as an open technique by Mumford and Gurd in 1941, distal clavicle excision has evolved greatly, with arthroscopic techniques currently predominating. No significant difference has been found in patient satisfaction or rate of complication between the techniques in a recent meta-analysis. Indeed, open excisions are still performed at a high rate, owing to the difficulty in technique and visualization with arthroscopic methods. One major critique of arthroscopic distal clavicle excision is difficulty safeguarding against under- and overexcision of the distal clavicle due to the lack of depth perception and visual reference points of the arthroscopic perspective. This Technical Note and accompanying video describe an indirect subacromial arthroscopic distal clavicle excision using a fluoroscopic Kirschner wire guide placed at the proximal border prior to resection to serve as a visual and mechanical reference to overexcision.

Histologic and magnetic resonance image evaluation in acromioclavicular joint osteoarthritis

Introduction

Little is known about the development of specific acromioclavicular joint osteoarthritis. Its histologic alterations are controversial, and radiologic alterations are seen in asymptomatic people. The objective of this study was to evaluate histologically the distal clavicle subchondral bone and to analyze magnetic resonance images in patients with painful and nonpainful acromioclavicular joint osteoarthritis.

Methods

An observational, analytical, and cross-sectional study with a control group was conducted. Between August 2018 and June 2019, we analyzed a total of 41 patients. Group 1 consisted of patients with pain in the acromioclavicular joint (symptomatic osteoarthritis), and group 2 consisted of patients without pain in the acromioclavicular joint (asymptomatic osteoarthritis).

Results

Twelve of the 15 patients with acromioclavicular joint pain (group 1) were female, 13 presented distal clavicle edema on magnetic resonance imaging, and 9 had subchondral bone edema on histologic examination. Patients with acromioclavicular joint pain had longer shoulder pain duration than patients without pain. Women were more likely to have acromioclavicular joint pain compared with men. Patients with edema on magnetic resonance imaging showed a greater chance of presenting pain in the acromioclavicular joint in comparison with patients without edema.

Conclusion

Women had a higher chance of presenting with acromioclavicular joint pain than men. Patients with edema on magnetic resonance imaging were more likely to present with pain than patients without edema. Patients with acromioclavicular joint pain had longer shoulder pain duration than patients without pain, and subchondral bone edema on histologic examination was more frequent in patients with pain.

Imaging of the Acromioclavicular Joint: Anatomy, Function, Pathologic Features, and Treatment

The acromioclavicular joint is an important component of the shoulder girdle; it links the axial skeleton with the upper limb. This joint, a planar diarthrodial articulation between the clavicle and the acromion, contains a meniscus-like fibrous disk that is prone to degeneration. The acromioclavicular capsule and ligaments stabilize the joint in the horizontal direction, while the coracoclavicular ligament complex provides vertical stability. Dynamic stability is afforded by the deltoid and trapezius muscles during clavicular and scapular motion. The acromioclavicular joint is susceptible to a broad spectrum of pathologic entities, traumatic and degenerative disorders being the most common. Acromioclavicular joint injury typically affects young adult males and can be categorized by using the Rockwood classification system as one of six types on the basis of the direction and degree of osseous displacement seen on conventional radiographs. MRI enables the radiologist to more accurately assess the regional soft-tissue structures in the setting of high-grade acromioclavicular separation, helping to guide the surgeon's selection of the appropriate management. Involvement of the acromioclavicular joint and its stabilizing ligaments is also important for understanding and classifying distal clavicle fractures. Other pathologic processes encountered at this joint include degenerative disorders; overuse syndromes; and, less commonly, inflammatory arthritides, infection, metabolic disorders, and developmental malformations. Treatment options for acromioclavicular dysfunction include conservative measures, resection arthroplasty for recalcitrant symptoms, and surgical reconstruction techniques for stabilization after major trauma.

Current evidence for nonpharmacological interventions and criteria for surgical management of persistent acromioclavicular joint osteoarthritis: A systematic review

BACKGROUND

The primary aim of this systematic review was to investigate the individual/combined effectiveness of nonpharmacological interventions in individuals with persistent acromioclavicular joint osteoarthritis. The secondary aims were to investigate the comparative effectiveness of nonpharmacological versus surgical interventions, and to identify the criteria used for defining failure of conservative interventions in individuals who require surgery for persistent acromioclavicular joint osteoarthritis.

METHOD

Major electronic databases were searched from inception until October 2018. Studies involving adults aged 16 years and older, diagnosed clinically and radiologically with isolated acromioclavicular joint osteoarthritis for at least three months or more were included. Studies must explicitly state the type and duration of conservative interventions. Methodological risk of bias was assessed using the Modified Downs and Black checklist.

RESULTS

Ten surgical intervention studies were included for final synthesis. No studies investigated the effectiveness of nonpharmacological interventions or compared them with surgical interventions. Common nonpharmacological interventions trialed from the 10 included studies were activity modification (n = 8) and physiotherapy (n = 4). Four to six months was the most often reported timeframe defining failure of conservative management (range 3-12 months).

CONCLUSIONS

Currently, there is no evidence to guide clinicians about the individual or combined effectiveness of nonpharmacological interventions for individuals with persistent acromioclavicular joint osteoarthritis.

Open versus arthroscopic acromioclavicular joint resection: a systematic review and meta-analysis

INTRODUCTION

The purpose of this study was to perform a meta-analysis comparing open and arthroscopic surgical techniques for distal clavicle resection.

METHODS

A systematic review of Medline, Embase, Scopus, and Google Scholar identified relevant publications in the English and German literature between 1997 and 2017. All included studies were levels I-IV, describing both treatments, with a minimum of 12 month follow-up, had at least one validated outcome score and documented patient recruitment, study design, demographic details, and surgical technique. Studies were excluded if they were only abstracts or conference proceedings, involved revision procedures, or the loss to follow-up exceeded 20%. Publication bias and risk of bias were assessed using the Cochrane Collaboration tools, and heterogeneity was assessed using the I² statistic.

RESULTS

Four studies (n = 319 patients) met the criteria for inclusion. The pooled estimate for clinical outcomes (Constant, ASES) demonstrated no significant differences (SMD 0.323, I² = 0%, p = 0.065) between open and arthroscopic resection, although the analysis favored open resection. The pooled estimate for clinical outcomes (SST) also demonstrated no significant differences (SMD 0.744, I² = 49.82%, p = 0.144) between open and arthroscopic resection, but the analysis again favored open resection. The pooled estimate for VAS assessment of pain demonstrated no differences (SMD 0.217, I² = 58.96%; p = 0.404) between open and arthroscopic resection.

CONCLUSION

The results of this study suggest that similar functional and clinical outcomes can be achieved with either open or arthroscopic distal clavicle resection. The observed trend that open resection may have a more favorable outcome warrants further investigation.

LEVEL OF EVIDENCE

Level 3; systematic review and meta-analysis.

Diagnosis and Management of Distal Clavicle Osteolysis

Distal clavicle osteolysis is an uncommon condition that most commonly affects weight lifters and other athletes who perform repetitive overhead activity. Although this condition most commonly presents in young active men, it is becoming increasing more common in women with the rise in popularity of body building and extreme athletics. Distal clavicle osteolysis can be debilitating, especially in those with rigorous training regimens, preventing exercise because of pain with activities such as bench presses and chest flies. Aside from a careful history and physical examination, radiographic evaluation is essential in distinguishing isolated distal clavicle osteolysis from acromioclavicular joint pathology, despite a potentially similar presentation of the 2 conditions. Nonoperative therapy that includes activity modification, nonsteroidal anti-inflammatory drugs, and cortisone injections is the first-line management for this condition. Patients whose conditions are refractory to nonoperative modalities may benefit from distal clavicle resection via either open or arthroscopic techniques. Arthroscopic techniques typically are favored because of improved cosmesis and the added benefit of the ability to assess the glenohumeral joint during surgery to rule out concomitant pathology. There are varying operative techniques even within arthroscopic management, with pros and cons of a direct and an indirect surgical approach. Patients often do well after such procedures and are able to return to their preinjury level of participation in a relatively short period. [Orthopedics. 2017; 40(2):119-124.].

Arthroscopic Distal Clavical Resection Using "Vis-à-Vis" Portal

Arthroscopic distal clavicle resection has become an increasingly popular procedure in orthopaedics, and various techniques have been published. Many of the arthroscopic distal clavicle resection techniques that have been reported require visualization from the lateral portal with an anterior working portal to perform the resection. While these techniques have reported high success rates, there is often difficulty in viewing the entire acromioclavicular joint from the 2 standard arthroscopic portals (lateral and anterior). This is due to the medial edge of the acromion blocking the ability to visualize the most superior and posterior portions of the distal clavicle. We propose a technique for arthroscopic distal clavicle resection using an accessory anterior portal.

Arthroscopic distal clavicle resection in symptomatic acromioclavicular joint arthritis combined with rotator cuff tear: a prospective randomized trial

BACKGROUND

The treatment of symptomatic acromioclavicular joint (ACJ) injury in the rotator cuff (RC) tear has not been well clarified.

PURPOSE

To compare the clinical results between patients who had distal clavicle resection (DCR) and those who did not during RC repair.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

From August 2008 to December 2009, a total of 56 consecutive patients (58 shoulders) were included. All patients had either a full-thickness or high-grade (>50%) RC tear, ACJ tenderness, arthritic change visible on plain radiographs, and a positive ACJ lidocaine injection test the day before surgery. Patients were randomized into 2 groups: DCR and RC repair (DCR+RCR group) and RC repair only (isolated RCR). Evaluation was performed preoperatively, at 6 months postoperatively, and at a final follow-up a minimum of 24 months postoperatively using the American Shoulder and Elbow Surgeons (ASES) score, the Constant shoulder score, range of motion examination, and pain visual analog scale (VAS).

RESULTS

After simple randomization, 26 shoulders were allocated in the DCR+RCR group, and 32 were placed in the isolated RCR group. Five shoulders in the DCR+RCR group and 6 in the isolated RCR group were excluded from analysis due to loss of follow-up. Therefore, the evaluation was performed for 21 shoulders in the DCR+RCR group and 26 shoulders in the isolated RCR group. The mean follow-up period was 44.2 months in the DCR+RCR group and 44.0 months in the isolated RCR group. There were no differences in age, sex, symptom duration, RC tear size, or preoperative ASES, Constant, and VAS scores between the 2 groups (P > .05). At final follow-up, the ASES, Constant, and VAS scores were significantly improved in both groups (P < .001). There were no differences in ASES, Constant, and VAS scores between the 2 groups at final follow-up (P > .05), and there was no difference in residual ACJ tenderness (7 in the DCR+RCR group and 5 in the isolated RCR group) between the 2 groups (P = .270).

CONCLUSION

There was no difference in the clinical evaluations between the combined arthroscopic DCR and RCR group and the isolated RCR group at a minimum 24-month follow-up. Arthroscopic DCR should be carefully considered in patients who have symptomatic ACJ arthritis with RC tears.

Outcome of distal clavicle resection in patients with acromioclavicular joint osteoarthritis and full-thickness rotator cuff tear

PURPOSE

The purpose of this study was to examine the impact of distal clavicle resection (DCR) on subjective and objective outcome measures in patients with acromioclavicular (AC) joint osteoarthritis (OA) and rotator cuff tear.

METHODS

Prospectively collected data of consecutive patients with arthroscopic evidence of OA of the ACJ with complete data at 2 years were used for the data analysis. Patients with moderate-to-severe OA of the AC joint underwent a DCR in conjunction with rotator cuff repair, while patients with mild OA of the ACJ underwent surgery related to concomitant rotator cuff tear without a DCR.

RESULTS

Data of 184 (72 females, 112 males, mean age: 62) patients with rotator cuff tear and varying degrees of OA of the AC joint were used for the analysis. Of 184 patients, 144 (78 %) had a resection of distal clavicle (resection group) and 40 (22 %) did not have a resection (no-resection group). Both groups showed a statistically significant (p < 0.0001) improvement in the American Shoulder and Elbow Surgeons (ASES) scores, Constant Murley score, and strength. Multivariable analysis showed that lower pre-operative ASES scores (higher disability), having a larger tear, an active compensation claim, and not having a DCR, had a negative impact on post-operative ASES scores.

CONCLUSION

When untreated surgically, even mild arthroscopic findings of AC joint OA may lead to a poorer outcome after rotator cuff repair. Further characterisation of patients in whom mild arthroscopic findings of OA of AC joint are clinically significant and warrant resection is needed.

LEVEL OF EVIDENCE

Retrospective outcome study, Level II.

Manual physical therapy for injection-confirmed nonacute acromioclavicular joint pain

STUDY DESIGN

Prospective single-cohort study.

OBJECTIVES

To determine and document changes in pain and disability in patients with primary, nonacute acromioclavicular joint (ACJ) pain treated with a manual therapy approach.

BACKGROUND

To our knowledge, there are no published studies on the physical therapy management of nonacute ACJ pain. Manual physical therapy has been successful in the treatment of other shoulder conditions.

METHODS

The chief inclusion criterion was greater than 50% pain relief with an ACJ diagnostic injection. Patients were excluded if they had sustained an ACJ injury within the previous 12 months. Treatment was conducted utilizing a manual physical therapy approach that addressed all associated impairments in the shoulder girdle and cervicothoracic spine. The primary outcome measure was the Shoulder Pain and Disability Index. Secondary measures were the American Shoulder and Elbow Surgeon and global rating of change scales. Outcomes were collected at baseline, 4 weeks, and 6 months. The Shoulder Pain and Disability Index and American Shoulder and Elbow Surgeon scale values were analyzed with a repeated-measures analysis of variance.

RESULTS

Thirteen patients (11 male; mean ± SD age, 41.1 ± 9.6 years) completed treatment consisting of an average of 6.4 sessions. Compared to baseline, there was a statistically significant and clinically meaningful improvement for the Shoulder Pain and Disability Index at 4 weeks (P = .001; mean, 25.9 points; 95% confidence interval [CI]: 11.9, 39.8) and 6 months (P<.001; mean, 29.8 points; 95% CI: 16.5, 43.0), and the American Shoulder and Elbow Surgeon scale at 4 weeks (P<.001; mean, 27.9 points; 95% CI: 14.7, 41.1) and 6 months (P<.001; mean, 32.6 points; 95% CI: 21.2, 43.9).

CONCLUSION

Statistically significant and clinically meaningful improvements were observed in all outcome measures at 4 weeks and 6 months, following a short series of manual therapy interventions. These results, in a small cohort of patients, suggest the efficacy of this treatment approach but need to be verified by a randomized controlled trial.

LEVEL OF EVIDENCE

Therapy, level 4.

Open versus arthroscopic distal clavicle resection

PURPOSE

The purpose of this systematic review was to critically evaluate the available literature in an attempt to compare the outcome of open versus arthroscopic distal clavicle resection in the treatment of acromioclavicular joint pathology.

METHODS

From January 1966 to December 2008, Medline was searched for the following key words: "acromioclavicular joint arthritis," "acromioclavicular osteolysis," "distal clavicle excision," "acromioclavicular joint excision," "Mumford," and "clavicle." Inclusion criteria included studies that compared the outcome of open versus arthroscopic distal clavicle resection. Studies that could not be translated into the English language or were not published in a peer-reviewed journal were excluded. Data were abstracted from the studies, including patient demographics, surgical procedure, rehabilitation, strength, range of motion, and clinical scoring system.

RESULTS

Seventeen studies met the inclusion criteria, including 2 Level II studies, 1 Level III and 14 Level IV studies. Arthroscopic distal clavicle excision results in more "good" or "excellent" outcomes compared with the open procedure. Both arthroscopic techniques result in success rates in excess of 90%, with the direct procedure permitting a quicker return to athletic activities. Performing distal clavicle excision in conjunction with either subacromial decompression or rotator cuff repair also has a high degree of success. A trend toward more "poor" results is seen when distal clavicle excision is performed in patients with post-traumatic acromioclavicular instability or in Workers' Compensation patients.

CONCLUSIONS

Our analysis suggests that among patients undergoing distal clavicle excision for acromioclavicular joint pathology, those having an arthroscopic procedure, specifically through the direct approach, can expect a faster return to activities while obtaining similar long-term outcomes compared with the open procedure.

LEVEL OF EVIDENCE

Level III, systematic review.

Open versus arthroscopic acromioclavicular joint resection: a retrospective comparison study

PURPOSE

The purpose was to compare open and arthroscopic acromioclavicular joint (ACJ) resection.

METHODS

We retrospectively reviewed 103 patients (105 shoulders) who underwent ACJ resection between 2000 and 2005. There were 56 women and 47 men with a mean age of 48 years. The mean duration of follow-up was 51 months (range, 15 to 91 months). Arthroscopic ACJ resection by use of a direct approach was performed in 81 shoulders (group A), and open ACJ resection was performed in 24 shoulders (group B). Results were graded according to pain relief both subjectively and objectively with cross-body adduction testing and direct palpation of the ACJ, subjective shoulder value, Constant score, and improved function.

RESULTS

The Constant scores increased from 50 (range, 34 to 65) to 89 (range, 39 to 100) in group A (P < .0001) and from 46 (range, 22 to 63) to 87 (range, 43 to 100) in group B (P < .0001). There was no statistical difference in the postoperative normalized Constant score between group A and group B (P = .47). Pain with cross-body adduction testing and palpation of the ACJ improved in 76 shoulders (94%) in group A and 22 shoulders (92%) in group B. No patients had signs or symptoms of ACJ anteroposterior instability. Revision ACJ resection was performed in 5 patients (5 shoulders [6.2%]) in group A and 1 shoulder (4.2%) in group B (P = .37). The radiographs of the patients who underwent revision showed that 3 patients (3.7%) from group A had regrowth of the distal clavicle; in addition, 2 patients (2.5%) from group A and 1 patient (4.3%) from group B had incomplete distal clavicle excision.

CONCLUSIONS

This study did not show a significant difference in the outcome between arthroscopic and open ACJ resection. Incomplete excision and regrowth of the distal clavicle are the most common causes of revision. Although only the arthroscopic group showed a small percentage of patients (3.7%) with regrowth of the distal clavicle, the number is too small to assume that this complication is the result of the arthroscopic technique only.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Analysis of the capsule and ligament insertions about the acromioclavicular joint: a cadaveric study

PURPOSE

The purpose of this study was to analyze the capsular and ligamentous insertions about the acromioclavicular (AC) joint to determine the amount of bone that can be removed without destabilizing the joint.

METHODS

We dissected 28 cadaveric shoulders. The AC ligament insertions were measured under loupe magnification with a digital caliper on the acromial and clavicular sides on the anterior, posterior, superior, and inferior edges. We measured the distance to the coracoacromial (CA) and coracoclavicular ligaments. In addition, the axial and coronal angle of the AC joint was measured.

RESULTS

The AC joint capsular insertion on the acromion begins, on average, 2.8 mm (range, 2.3 to 3.3 mm) from the medial acromion and begins on the lateral clavicle a mean of 3.5 mm (range, 2.9 to 3.9 mm) from the distal clavicle. The mean capsular width ranged from 1.6 to 2.9 mm. The mean distance from the medial acromion to the CA ligament insertion was 3.5 mm. The mean axial angle of the AC joint was 51 degrees , with a 12 degrees coronal angle. The mean distance from the lateral clavicle to the start of the trapezoid ligament was 14.7 mm, and that to the conoid ligament was 32.1 mm.

CONCLUSIONS

An anatomic-based recommendation for safe AC joint resection is that 2 to 3 mm of the medial acromion and 3 to 4 mm of the distal clavicle can be resected without removing the AC capsular insertions. The trapezial and CA attachments are in close proximity to the AC capsular insertions. Medial resections greater that 15 mm will begin to take down the trapezoid ligament. Arthroscopic bone resection should be directed into the AC joint at approximately 50 degrees in the axial plane and 12 degrees in the coronal plane for safe symmetric resection.

CLINICAL RELEVANCE

These anatomic measurements suggest that AC joint resections (5 to 7 mm) with 2 to 3 mm from the acromial side and 3 to 4 mm from the clavicular side will not disrupt the stabilizing ligaments of the AC joint after distal clavicle resection.

Injuries to the acromioclavicular joint

Injuries to the acromioclavicular joint are common but underdiagnosed. Sprains and minor subluxations are best managed conservatively, but there is debate concerning the treatment of complete dislocations and the more complex combined injuries in which other elements of the shoulder girdle are damaged. Confusion has been caused by existing systems for classification of these injuries, the plethora of available operative techniques and the lack of well-designed clinical trials comparing alternative methods of management. Recent advances in arthroscopic surgery have produced an even greater variety of surgical options for which, as yet, there are no objective data on outcome of high quality. We review the current concepts of the treatment of these injuries.

Arthroscopic distal clavicle resection: a biomechanical analysis of resection length and joint compliance in a cadaveric model

PURPOSE

The purposes of this study were to assess the effects of a distal clavicle resection of less than 5 mm on bony contact and compliance in the acromioclavicular (AC) joint and to localize areas of persistent contact in the AC joint. The hypothesis of this study was that AC contact can be avoided by excising less than 5 mm of bone from the distal clavicle.

METHODS

Ten human AC joints underwent compressive loading of the distal clavicle into the acromion after the following: disk excision, distal clavicle resection of 2.5 mm, and distal clavicle resection of 5 mm. The joint resistance force, stiffness, and presence and location of contact were monitored.

RESULTS

Excising 2.5 mm or less resulted in no bone-to-bone abutment in 6 of 10 specimens. A 5-mm resection resulted in successful decompression in all specimens. The specimens that required a 5-mm resection had minimal contact after the 2.5-mm resection (inferior-posterior quadrant only). AC joint stiffness decreased significantly with increasing amounts of clavicular resection (P = .01).

CONCLUSIONS

A 5-mm distal clavicle resection guaranteed no abutment but decreased joint stiffness. Persistent contact occurred only in the inferior-posterior quadrant of the joint after a 2.5-mm resection.

CLINICAL RELEVANCE

These findings support the efficacy of a 5-mm distal clavicle resection for eliminating bony contact but suggest that there is a bony contribution to AC joint stiffness. A resection of 2.5 to 5.0 mm could be adequate if care is taken to excise a greater depth of bone in the inferior-posterior quadrant.