Biomechanical Comparison of Anatomic and Extra-Anatomic Reconstruction Techniques Using Local Grafts for Chronic Instability of the Acromioclavicular Joint

Treatment of Failed Coracoclavicular Ligament Reconstructions: Primary Acromioclavicular Ligament and Capsular Reconstruction and Revision Coracoclavicular Ligament Reconstruction

Acromioclavicular (AC) joint dislocations are a common injury affecting 2 of every 10,000 people in the general population and comprise 9% to 12% of all injuries to the shoulder. Most injuries occur through contact activity, which drives the acromion inferiorly with the clavicle remaining in its anatomic position, initiating a cascade of injury propagating from the AC ligament followed by failure of the coracoclavicular ligaments. Many techniques have been described for AC joint injuries, without a consensus gold standard. The revision setting offers even less consensus on treatment options and countless difficulties for surgeons. There have been more than 60 described procedures regarding AC and coracoclavicular ligament reconstructions, with significant controversy regarding the optimal intervention for each injury. When these techniques fail, it is important to pinpoint the mechanism of failure to construct a successful plan for revision. The purpose of this Technical Note is to describe our preferred method of primary AC and revision coracoclavicular reconstruction using a combination of autograft and allograft semitendinosus as well as TightRope fixation.

Combination of Surgical Techniques Restores Multidirectional Biomechanical Stability of Acromioclavicular Joint

PURPOSE

To measure the multiaxial stability of the acromioclavicular joint before and after transection of the acromioclavicular capsule and coracoclavicular ligaments and after sequential repair of acromioclavicular and coracoclavicular ligaments.

METHODS

Biomechanical testing was performed on fresh-frozen human cadaveric shoulders (N = 6). Translational and rotational stability in the vertical and horizontal planes was measured in intact specimens, after transecting the acromioclavicular and coracoclavicular ligaments, and after sequentially performing the following procedures: single-bundle coracoclavicular repair (CCR), modified Weaver-Dunn procedure (WD), and acromioclavicular stabilization (ACS).

RESULTS

Resecting the acromioclavicular and coracoclavicular significantly reduced translational stiffness in the inferior and anteroposterior directions, as well as rotational stiffness about the vertical and anteroposterior axes. All 3 surgical procedures increased inferior translational stiffness relative to the intact condition (Intact: 38 ± 9 N/mm, CCR: 54 ± 23 N/mm (P = .03), CCR+WD 52 ± 20 N/mm (P = .07), CCR ± WD+ACS 50 ± 21 N/mm (P = .17)). However, the combination of CCR, modified WD, and ACS resulted in the greatest increase in stiffness in internal rotation (Intact: 12.5 ± 7.4 cNm/deg, CCR: 1.2 ± 1.1 cNm/deg, CCR+WD 7.2 ± 3.0 N∗m/deg [P = .023], CCR+WD+ACS 11.6 ± 4.9 cNm/deg [P = .055]).

CONCLUSIONS

The cumulative stability of CCR, WD reconstruction, and ACS appears to be additive. Our findings provide a biomechanical justification for combining all three techniques. Biomechanical studies assessing the performance of various acromioclavicular repairs and reconstructions should therefore incorporate multiaxial testing in their protocols.

CLINICAL RELEVANCE

Multiple points of fixation that provide multidirectional stability have the potential to improve clinical outcomes and reduce failure rates of acromioclavicular joint repair or stabilization.

Treatment of Acromioclavicular Joint Instability With a Tunnel-Free Reconstruction Technique

Acromioclavicular joint injuries are a common shoulder injury encountered by orthopaedic surgeons. Many different surgical techniques have been described for the operative treatment of these injuries with no single, clear gold standard technique on which surgeons agree. Among the most common complications after surgical management of acromioclavicular injuries are loss of reduction, infection, fracture of clavicle or coracoid, and need for reoperation. We propose an arthroscopic-assisted, tunnel-free surgical technique using a tibialis anterior allograft combined with a FiberTape Cerclage (Arthrex, Naples, FL) to manage both acute and chronic acromioclavicular joint injuries. No bony tunnels are drilled and no hardware is implanted, which should obviate the risk for subsequent bony failure through a fracture, nor require subsequent hardware removal. In addition, the combination of suspensory and allograft fixation should impart sufficient stability to maintain an adequate reduction even in the face of failure of one of the fixation methods.

Modified Weaver-Dunn Technique Using Transosseous Bone Tunnels and Coracoid Suture Augmentation

INTRODUCTION

A modified Weaver-Dunn procedure for the management of acromioclavicular joint injuries that uses transosseous bone tunnels and coracoid suture augmentation is described with associated clinical results.

METHODS

A retrospective review of 39 consecutive patients who underwent a primary mWD procedure by a single surgeon from January 2013 to July 2019 was conducted. Patient charts and radiographs were reviewed for clinical course, complications and management, and radiographic evaluation. Satisfaction, American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation, and Simple Shoulder Test scores were obtained.

RESULTS

A total of 28 patients (72%) with a mean follow-up of 37.5 (12 to 84 months) and a mean age of 44.3 ± 15.1 years were included. Postoperative ASES, Simple Shoulder Test, Single Assessment Numeric Evaluation, and satisfaction scores were 90.6 ± 14.2, 11.1 ± 1.5, 87.3 ± 10.2, and 4.4 ± 1.2 (out of 5), respectively, with a significant improvement in ASES of 42.2 ± 21.8 points (P < 0.001). All patients had significant decrease in coracoclavicular distance (P < 0.001). Three patients (10.7%) had complications, with two (7.1%) requiring additional surgery.

CONCLUSION

Excellent functional and radiographic outcomes can be achieved with this modified Weaver-Dunn technique. Complication and revision rates are comparable with those that are found in the literature.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.

Rotator Cuff Repair Using Coracoacromial Ligament Autograft for Supraspinatus Footprint Augmentation

Failure of rotator cuff repair can be a disastrous clinical outcome. Although failure is a multifactorial issue, recent interest has piqued in understanding the biology of the insertional components of the supraspinatus and infraspinatus at the footprint. When the torn tendon is of poor quality, especially if it is diminutive or thin, rotator cuff repair augmentation should be considered to aid in long-term healing. Various allograft options have been described in the past, and more recently, xenografts and synthetics have become more commonly used. The use of autografts in the treatment of insertional footprint deficiency has great potential; however, few grafts have been described. This study describes the surgical technique for footprint augmentation in arthroscopic supraspinatus repair using harvested autologous coracoacromial ligament tissue.

Nonanatomic and Suture-Based Coracoclavicular Joint Stabilization Techniques Provide Adequate Stability at a Lower Cost of Implants in Biomechanical Studies When Compared With Anatomic Techniques: A Systematic Review and Meta-Analysis

Purpose

To compare the stability and cost of the used implants in nonanatomic and anatomic acromioclavicular joint repair/reconstruction (ACCR) techniques tested in cadaveric shoulder biomechanical studies during the last decade.

Methods

A systematic review and meta-analysis were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and prospectively registered in PROSPERO. Two independent reviewers searched PubMed, Embase, and Virtual Health Library databases. Studies evaluating 3-direction stability under 70-N loads and load-to-failure protocols with servohydraulic testing systems were included. A meta-analysis of the mean differences of anterior, posterior, and superior direction; relative stability value in 3 directions; superior direction load-to-failure; stability/cost index; and load-to-failure/cost index was performed using a continuous random-effects model and 95% confidence interval.

Results

Eighteen articles were included. Both non-ACCR and ACCR techniques exceeded the minimum acceptable threshold of stability and load-to-failure. ACCR techniques were biomechanically better in terms of anterior stability (P = .04) and relative stability value (mean difference 64.08%, P = .015). However, supraphysiological stability and failure loads were achieved with non-ACCR techniques at a lower cost of implants. Techniques combining 2 clavicular tunnels separated by at least 10 mm, a mean of 2 sutures, and/or suture tapes had the greatest stability/cost index and load-to-failure/cost index among the included techniques (confidence interval 99%).

Conclusions

Non-ACCR and ACCR techniques exceeded the minimum acceptable threshold of stability and failure loads in controlled biomechanical testing. However, non-ACCR and techniques combining 2 clavicular tunnels separated by at least 10 mm, a mean of 2 sutures, and/or suture tapes provide supraphysiologic stability and failure loads at a lower cost of implants.

Clinical Relevance

Non-ACCR and suture-based techniques may provide more cost-effective and greater value treatment for acromioclavicular joint injury and could be considered in the surgical management of normal activity individuals and cost-sensitive populations.

Review of Weaver and Dunn on treatment of acromioclavicular injuries, especially complete acromioclavicular separation

This classic discusses the original publication "Treatment of acromioclavicular injuries, especially complete acromioclavicular separation" by Weaver and Dunn, which collaborated to develop a technique for acromioclavicular joint reconstruction in 1972. Their surgical technique described resection of 2 cm of the distal clavicle and transfer of the acromial end of the coracoacromial ligament into the medullary canal of the distal clavicle. (modified) Weaver-Dunn procedures have been regarded as one of the most effective techniques to treat complete acromioclavicular joint dislocation for a long time. However, anatomic reconstructions have taken over this position since recent biomechanical studies have demonstrated superior results. Although the Weaver-Dunn procedure has fallen out of favour, it remains of historical significance. For this reason, this review will comprise the historical overview of the Weaver-Dunn procedure, the men behind the eponym and the clinical implication then and now.

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.

Optimal Management of Acromioclavicular Dislocation: Current Perspectives

Injuries to the acromioclavicular (AC) joint are common and mostly involve younger, male individuals. Whereas the majority of AC joint dislocations can be treated nonoperatively with a trial of immobilization, pain medication, cryotherapy, and physiotherapy, there are patients that do not respond well to conservative management and may require surgical treatment. Identifying and treating these patients according to the type and chronicity of AC joint dislocation is paramount. To date, a myriad of surgical techniques have been proposed to address unstable AC joint dislocations and are indicative of the uncertainty that exists in optimal management of these injuries. Historically research has focused on the restoration of the coracoclavicular ligament complex. However, recently the importance of the acromioclavicular capsule and ligaments has been emphasized. This review aims to provide the reader with an overview of current treatment strategies and research, as well as future perspectives.

Surgical versus conservative interventions for treating acromioclavicular dislocation of the shoulder in adults

BACKGROUND

Dislocation of the acromioclavicular joint is one of the most common shoulder injuries in a sport-active population. The question of whether surgery should be used remains controversial. This is an update of a Cochrane Review first published in 2010.

OBJECTIVES

To assess the effects (benefits and harms) of surgical versus conservative (non-surgical) interventions for treating acromioclavicular dislocations in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (to June 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2019, Issue 6), MEDLINE (1946 to June 2019), Embase (1980 to June 2019), and LILACS (1982 to June 2019), trial registries, and reference lists of articles. There were no restrictions based on language or publication status.

SELECTION CRITERIA

We included all randomised and quasi-randomised trials that compared surgical with conservative treatment of acromioclavicular dislocation in adults.

DATA COLLECTION AND ANALYSIS

At least two review authors independently performed study screening and selection, 'Risk of bias' assessment, and data extraction. We pooled data where appropriate and used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included five randomised trials and one quasi-randomised trial. The included trials involved 357 mainly young adults, the majority of whom were male, with acute acromioclavicular dislocation. The strength of the findings in all studies was limited due to design features, invariably lack of blinding, that carry a high risk of bias. Fixation of the acromioclavicular joint using hook plates, tunnelled suspension devices, coracoclavicular screws, acromioclavicular pins, or (usually threaded) wires was compared with supporting the arm in a sling or similar device. After surgery, the arm was also supported in a sling or similar device in all trials. Where described in the trials, both groups had exercise-based rehabilitation. We downgraded the evidence for all outcomes at least two levels, invariably for serious risk of bias and serious imprecision.Low-quality evidence from two studies showed no evidence of a difference between groups in shoulder function at one year, assessed using the Disability of the Arm, Shoulder, and Hand questionnaire (DASH) (0 (best function) to 100 (worst function)): mean difference (MD) 0.73 points, 95% confidence interval (CI) -2.70 to 4.16; 112 participants. These results were consistent with other measures of function at one-year or longer follow-up, including non-validated outcome scores reported by three studies. There is low-quality evidence that function at six weeks may be better after conservative treatment, indicating an earlier recovery. Very low-quality evidence from one trial found no difference between groups in participants reporting pain at one year: risk ratio (RR) 1.32, 95% CI 0.54 to 3.19; 79 participants. There is very low-quality evidence that surgery may not reduce the risk of treatment failure, usually resulting in non-routine secondary surgery: 14/168 versus 15/174; RR 0.99, 95% CI 0.51 to 1.94; 342 participants, 6 studies. The main source of treatment failure was complications related to surgical implants in the surgery group and persistent symptoms, mainly discomfort, due to the acromioclavicular dislocation in the conservatively treated group.There is low-quality evidence from two studies that there may be little or no difference between groups in the return to former activities (sports or work) at one year: 57/67 versus 62/70; RR 0.96, 95% CI 0.85 to 1.10; 137 participants, 2 studies. Low-quality but consistent evidence from four studies indicated an earlier recovery in conservatively treated participants compared with those treated with surgery. There is low-quality evidence of no clinically important difference between groups at one year in quality of life scores, measured using the 36-item or 12-item Short Form Health Survey (SF-36 or SF-12) (0-to-100 scale, where 100 is best score), in either the physical component (MD -0.63, 95% CI -2.63 to 1.37; 122 participants, 2 studies) or mental component (MD 0.47 points, 95% CI -1.51 to 2.44; 122 participants). There is very low-quality and clinically heterogenous evidence of a greater risk of an adverse event after surgery: 45/168 versus 16/174; RR 2.82, 95% CI 1.65 to 4.82; 342 participants, 6 studies; I² = 48%. Common adverse outcomes were hardware complications or discomfort (18.5%) and infection (8.7%) in the surgery group and persistent symptoms (7.1%), mainly discomfort, in the conservatively treated group. The majority of surgical complications occurred in older studies testing now-outdated devices known for their high risk of complications. The very low-quality evidence from one study (70 participants) means that we are uncertain whether there is a between-group difference in patient dissatisfaction with cosmetic results.It is notable that the evidence for function, return to former activities, and quality of life came from the two most recently conducted studies, which tested currently used devices and interventions in clearly defined participant populations that represented the commonly perceived population for which there is uncertainty over the use of surgery. There were insufficient data to conduct subgroup analysis relating to type of injury and whether surgery involved ligament reconstruction or not.

AUTHORS' CONCLUSIONS

There is low-quality evidence that surgical treatment has no additional benefits in terms of function, return to former activities, and quality of life at one year compared with conservative treatment. There is, however, low-quality evidence that people treated conservatively had improved function at six weeks compared with surgical management. There is very low-quality evidence of little difference between the two treatments in pain at one year, treatment failure usually resulting in secondary surgery, or patient satisfaction with cosmetic result. Although surgery may result in more people sustaining adverse events, this varied between the trials, being more common in techniques such as K-wire fixation that are rarely used today. There remains a need to consider the balance of risks between the individual outcomes: for example, surgical adverse events, including wound infection or dehiscence and hardware complication, against risk of adverse events that may be more commonly associated with conservative treatment such as persistent symptoms or discomfort, or both.There is a need for sufficiently powered, good-quality, well-reported randomised trials of currently used surgical interventions versus conservative treatment for well-defined injuries.

A New Coracoclavicular Guider for Minimally Invasive Anatomic Coracoclavicular Reconstruction with Two TightRope Systems in Acute Acromioclavicular Joint Dislocation

High-grade injuries of complete acromioclavicular (AC) joint disruption (types IV - VI) are typically treated surgically. Since the coracoclavicular (CC) ligament is most often used for stabilizing the AC joint, most reconstruction techniques to treat dislocation of this joint rely upon CC interval fixation. A TightRope system is usually used to augment the CC ligament to treat acute AC dislocations with arthroscopic assistance. The conventional arthroscopic technique employing one TightRope system is associated with some complications, including anterior subluxation of the clavicle and clavicular bony avulsion as a consequence of rotational movements. As an alternative, two TightRope systems can be used to anatomically reconstruct the CC ligament to avoid these complications. We present a new CC guider with which the surgeon can replicate the native CC ligament complex orientation using two TightRope systems via two minimally invasive incisions without arthroscopic assistance. This procedure relies upon the accommodation and stable placement of the clavicle and coracoid bone tunnels for the two TightRope systems in place of the trapezoid and conoid of the CC ligament. We retrospectively reviewed the outcomes for 16 patients with acute dislocation of the AC joint that had been treated by a single surgeon using a double-button fixation system. An independent reviewer conducted functional testing of these patients, including the use of Disability of Arm, Shoulder and Hand (DASH), Constant and visual analog scale (VAS) scores. Standard radiographs were used for assessing the CC distance for the impacted shoulder relative to that of the unaffected contralateral shoulderThe new CC guider leads to an excellent cosmetic result. Our clinical results show that this technique can be easily performed and is similarly invasive to other current arthroscopic techniques.

Arthroscopic Coracoacromial Ligament Transfer Augmented With Suspensory V-Shaped Fixation System for Chronic Acromioclavicular Joint Dislocation

Chronic acromioclavicular joint dislocations (ACJDs) develop when there is failure of conservative treatment, failed surgical treatment of acute ACJD, or simply missing the treatment in the acute healing phase. There is wide agreement that mechanical fixation alone in chronic ACJD is not sufficient and biological augmentation is necessary. Various arthroscopic techniques for reconstruction of the coracoclavicular ligament have been described, but allografts are expensive, are not available in all centers, carry the risk of disease transmission, and are "dead tissue" with a poor capacity for healing. Autografts are associated with donor-site morbidity and avascular structures. Moreover, these grafts are associated with a high risk of clavicular or coracoid fractures owing to large tunnels. We present an arthroscopic technique to transfer the coracoacromial ligament to the inferior surface of the lateral part of the clavicle in chronic ACJD, augmented with 2 clavicular buttons and a single coracoid button in a V-shaped configuration. The technique has various advantages including better stabilization, anatomic reconstruction, and a minimal risk of fracture of the coracoid and clavicle with small tunnels, using a vascularized graft with arthroscopic control of reduction.