Arthroscopically assisted stabilization of chronic AC-joint instabilities in GraftRope™ technique with an additive horizontal tendon augmentation

Proximal humerus fracture and acromioclavicular joint dislocation

Proximal humerus fractures and injuries to the acromioclavicular joint are among the most common traumatic diseases of the upper extremity. Fractures of the proximal humerus occur most frequently in older people and are an indicator fracture of osteoporosis. While a large proportion of only slightly displaced fractures can be treated non-operatively, more complex fractures require surgical treatment. The choice of optimal treatment and the decision between joint-preserving surgery by means of osteosynthesis or endoprosthetic treatment is often a difficult decision in which both fracture morphology factors and individual factors should be taken into account. If endoprosthetic treatment is indicated, satisfactory long-term functional and clinical results have been achieved with a reverse shoulder arthroplasty. Injuries to the acromioclavicular joint occur primarily in young, athletic individuals. The common classification according to Rockwood divides the injury into 6 degrees of severity depending on the dislocation. This classification forms the basis for the decision on non-operative or surgical treatment. The indication for surgical treatment for higher-grade injuries is the subject of controversial debate in the latest literature. In chronic injuries, an autologous tendon transplant is also performed. Whereas in the past, treatment was often carried out using a hook plate, which was associated with complications, the gold standard today is minimally invasive treatment using Endobutton systems. This review provides an overview of the two injury patterns and discusses the various treatment options.

Clavicular tunnel widening after coracoclavicular stabilization surgery: a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to (1) estimate the prevalence of clavicular tunnel widening (TW) after coracoclavicular stabilization surgery and its risk factors and (2) assess whether TW is correlated with clavicle fracture or loss of reduction of the acromioclavicular joint (ACJ).

METHODS

In January 2023, 3 electronic databases were searched to collect data on postoperative clavicular TW, its prevalence, magnitude, and correlation with fracture and ACJ loss of reduction. Studies were classified according to the time of surgical intervention, and the clavicular tunnels were categorized by their anatomic location. Mean differences were calculated using a DerSimonian-Laird random-effects model, while binomial outcomes were pooled using the Freeman-Tukey double arcsine transformation. Univariate and multivariate meta-regression analyses were performed to determine the effect of several variables on the proportion of cases with TW.

RESULTS

Fifteen studies (418 shoulders) were included. At the final follow-up, evidence of clavicular TW was found in 70% (95% confidence interval [CI]: 70%-87%; I2 = 89%) of 221 shoulders. Surgeries in acute cases had a lower prevalence of TW (52%) compared to chronic cases (71%) (P < .001). Significant TW was found in the central tunnel (3.2 mm; 95% CI: 1.8-4.6 mm; P < .001; I2 = 72%) for acute injuries and in the medial (1.2 mm; 95% CI: 0.7-1.7 mm; P < .001; I2 = 77%) and lateral (1.5 mm; 95% CI: 0.7-2.3 mm; P < .001; I2 = 77%) tunnels for chronic cases. Single central-tunnel techniques were positively associated with the prevalence of TW (P = .046), while biotenodesis screw fixation was associated with a lower prevalence (P = .004) in chronic cases. Reconstruction of the ACJ ligament complex with tendon grafts or sutures was associated with a higher prevalence of TW (P < .001). Drill sizes between 2.5 and 5 mm were significantly associated with a lower prevalence of TW, regardless of injury chronicity (P = .012). No correlation was found between TW and the loss of ACJ reduction or clavicle fractures.

CONCLUSIONS

This systematic review and meta-analysis explored TW occurrence following coracoclavicular stabilization surgery. TW was observed in 70% of patients at final follow-up, with a higher prevalence in chronic than in acute cases. Modifiable surgical variables, such as single-tunnel tendon graft constructs for acute or chronic injuries and knotted graft procedures for chronic injuries, were significantly associated with TW. Furthermore, the prevalence of TW increased with concomitant surgical treatment of the ACJ ligament complex, and decreased with drill sizes between 2.5 and 5 mm, regardless of lesion chronicity. These surgical variables should be considered when establishing transosseous tunnels for coracoclavicular stabilization. Clavicle fractures and TW mechanisms require further investigation.

An In Vitro Study Demonstrating the Significance of Acromioclavicular Ligament Repair in Restoring Horizontal and Rotational Acromioclavicular Joint Stability

BACKGROUND

The principle of joint reconstruction surgery is to try to recreate the native joint biomechanics and stability. With respect to acromioclavicular joint (ACJ) surgery, much focus to date has been on restoring the superoinferior stability. There is concern that persistent horizontal instability following ACJ reconstruction could lead to poorer patient outcomes; therefore, we evaluated whether acromioclavicular (AC) ligament repair offers improved horizontal stability in conjunction with ACJ reconstruction.

METHODS

A whole-body human cadaver was used. The ACJ was exposed and subjected to a constant 70N load on the lateral end of the clavicle to test the anteroposterior (AP), superoinferior (SI), and horizontal pivot angle (HPA) around the ACJ. The AC and coracoclavicular (CC) ligaments were subsequently divided, and the above three parameters were re-tested. Ligament augmentation and reconstruction system (Corin Group, Cirencester, UK), LockDown (LockDown Medical Limited, Redditch, UK), Endobutton (Smith and Nephew Inc., London, UK), and Neoligament implant (Xiros Ltd., Leeds, UK) were used to reconstruct the CC ligaments and tested with and without AC repair.

RESULTS

The native ACJ allowed an average 2.48 mm AP and 3.88 mm SI translation with a 27° HPA. All synthetic implants significantly improved the vertical stability of the ACJ but allowed up to a four-fold increase in AP translation. Coupled with ACJ repair, all the reconstructions were far superior, especially in restoring horizontal stability.

CONCLUSION

The implants varied in their approach to fixation and concentrated primarily on the reconstruction of CC ligaments. Our study was able to demonstrate that AC repair significantly improves the stability of the construct and significantly reduces vertical and horizontal instability.

In Vivo Analysis of Acromioclavicular Kinematics and Distance During Multiplanar Humeral Elevation

BACKGROUND

Knowledge of acromioclavicular (AC) joint kinematics and distance may provide insight into the biomechanical function and development of new treatment methods. However, accurate data on in vivo AC kinematics and distance between the clavicle and acromion remain unknown.

PURPOSE/HYPOTHESIS

The purpose of this study was to investigate 3-dimensional AC kinematics and distance during arm elevation in abduction, scaption, and forward flexion in a healthy population. It was hypothesized that AC kinematics and distance would vary with the elevation angle and plane of the arm.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 19 shoulders of healthy participants were enrolled. AC kinematics and distance were investigated with a combined dual fluoroscopic imaging system and computed tomography. Rotation and translation of the AC joint were calculated. The AC distance was measured as the minimum distance between the medial border of the acromion and the articular surface of the distal clavicle (ASDC). The minimum distance point (MDP) ratio was defined as the length between the MDP and the posterior edge of the ASDC divided by the anterior-posterior length of the ASDC. AC kinematics and distance between different elevation planes and angles were compared.

RESULTS

Progressive internal rotation, upward rotation, and posterior tilt of the AC joint were observed in all elevation planes. The scapula rotated more upward relative to the clavicle in abduction than in scaption (P = .002) and flexion (P = .005). The arm elevation angle significantly affected translation of the AC joint. The acromion translated more laterally and more posteriorly in scaption than in abduction (P < .001). The AC distance decreased from the initial position to 75° in all planes and was significantly greater in flexion (P < .001). The MDP ratio significantly increased with the elevation angle (P < .001).

CONCLUSION

Progressive rotation and significant translation of the AC joint were observed in different elevation planes. The AC distance decreased with the elevation angle from the initial position to 75°. The minimum distance between the ASDC and the medial border of the acromion moved anteriorly as the shoulder elevation angle increased.

CLINICAL RELEVANCE

These results could serve as benchmark data for future studies aiming to improve the surgical treatment of AC joint abnormalities to restore optimal function.

Deltotrapezial Stabilization of Acromioclavicular Joint Rotational Stability: A Biomechanical Evaluation

Background

Despite advances in surgical management of acromioclavicular (AC) joint reconstruction, many patients fail to maintain sustained anatomic reduction postoperatively.

Purpose

To determine the biomechanical support of the deltoid and trapezius on AC joint stability, focusing on the rotational stability provided by the muscles to posterior and anterior clavicular rotation. A novel technique was attempted to repair the deltoid and trapezius anatomically.

Study Design

Controlled laboratory study.

Methods

Twelve human cadaveric shoulders (mean ± SD age, 60.25 ± 10.25 years) underwent servohydraulic testing. Shoulders were randomly assigned to undergo serial defects to either the deltoid or trapezius surrounding the AC joint capsule, followed by a combined deltotrapezial muscle defect. Deltotrapezial defects were repaired with an all-suture anchor using an anatomic technique. The torque (N·m) required to rotate the clavicle 20° anterior and 20° posterior was recorded for the following conditions: intact (native), deltoid defect, trapezius defect, combined deltotrapezial defect, and repair.

Results

When compared with the native condition, the deltoid defect decreased the torque required to rotate the clavicle 20° posteriorly by 7.1% (P = .206) and 20° anteriorly by 6.1% (P = .002); the trapezial defect decreased the amount of rotational torque posteriorly by 5.3% (P = .079) and anteriorly by 4.9% (P = .032); and the combined deltotrapezial defect decreased the amount of rotational torque posteriorly by 9.9% (P = .002) and anteriorly by 9.4% (P < .001). Anatomic deltotrapezial repair increased posterior rotational torque by 5.3% posteriorly as compared with the combined deltotrapezial defect (P = .001) but failed to increase anterior rotational torque (P > .999). The rotational torque of the repair was significantly lower than the native joint in the posterior (P = .017) and anterior (P < .001) directions.

Conclusion

This study demonstrated that the deltoid and trapezius play a role in clavicular rotational stabilization. The proposed anatomic repair improved posterior rotational stability but did not improve anterior rotational stability as compared with the combined deltotrapezial defect; however, neither was restored to native stability.

Clinical Relevance

Traumatic or iatrogenic damage to the deltotrapezial fascia and the inability to restore anatomic deltotrapezial attachments to the acromioclavicular joint may contribute to rotational instability. Limiting damage and improving the repair of these muscles should be a consideration during AC reconstruction.

The Role of the Trapezius in Stabilization of the Acromioclavicular Joint: A Biomechanical Evaluation

Background

Acromioclavicular joint (ACJ) injuries are common, and many are adequately treated nonoperatively. Biomechanical studies have mainly focused on static ligamentous stabilizers. Few studies have quantified ACJ stabilization provided by the trapezius.

Purpose/Hypothesis

To elucidate the stabilization provided by the trapezius to the ACJ during scapular internal and external rotation (protraction and retraction). It was hypothesized that sequential trapezial resection would result in increasing ACJ instability.

Study Design

Controlled laboratory study.

Methods

A biomechanical approach was pursued, with 10 cadaveric shoulders with the trapezius anatomically force loaded to normal. The trapezius was then serially transected over 8 trials, which alternated between clavicular defects (CD) and scapular defects (SD); each sequential defect consisted of 25% of the clavicular or scapular trapezial attachment. After each defect, specimens were tested with angle-controlled scapular internal and external rotation (12°) with rotary torque measurements to evaluate ACJ stability.

Results

The mean resistance in rotary torque for 12° of scapular internal rotation (protraction) with native specimens was 7.0 ± 2.0 N·m. Overall, internal rotation demonstrated a significant decrease in ACJ stability with trapezial injury (P < .001). Eight sequential defects resulted in the following significant percentage decreases in rotary torque from native internal rotation: 1.5% (25% CD; 0% SD), 5.6% (25% CD; 25% SD), 5.1% (50% CD; 25% SD), 6.5% (50% CD; 50% SD), 3.8% (75% CD; 50% SD), 7.1% (75% CD; 75% SD), 6.7% (100% CD; 75% SD), and 12.3% (100% CD 100% SD) (P < .001). The mean resistance in rotary torque for 12° of scapular external rotation (retraction) with native specimens was 7.1 ± 1.7 N·m. External rotation did not demonstrate a significant decrease in ACJ stability with trapezial injury (P = .596). The 8 sequential defects resulted in decreases in rotary torque from native external rotation of 0%, 3.8%, 4.0%, 3.2%, 3.5%, 3.4%, 4.2%, and 0.7%.

Conclusion

Trapezial injury resulted in increased instability in the setting of scapular internal rotation (protraction) of the ACJ.

Clinical Relevance

These findings validate the inclusion of deltotrapezial fascial injury consideration in the modified Rockwood classification system. Repair of the trapezial insertion on the ACJ may provide improved outcomes in the setting of ACJ reconstruction.

Arthroscopically assisted single tunnel reconstruction for acute high-grade acromioclavicular joint dislocation with an additional acromioclavicular joint cerclage

PURPOSE

Purpose of this study was to demonstrate that a single tunnel reconstruction of high-grade acromioclavicular (AC) joint instabilities with implants of the second generation is sufficient for stabilisation, especially in combination with an AC cerclage.

METHODS

Patients with an acute AC-joint dislocation type Rockwood III-B and V were included. Besides clinical follow-up examination, radiographs were analysed. The functional outcome measures were Constant Score (CS), Taft score (TS), ACJI score and patient's satisfaction. Horizontal instability was evaluated by clinical examination and radiological with an Alexander view.

RESULTS

Thirty-five patients with a mean follow-up of 29 months were included. Ninety-seven per cent were satisfied with their result, with an average Subjective Shoulder Value of 90%. The CS averaged at 90 ± 10 points, TS at 11 ± 1 points and ACJI at 78 ± 18 points. Radiologically, 3 of 29 patients (10%) showed a persisting horizontal instability. The coracoclavicular (CC) distance improved from 22 preoperative to 10 mm postoperative, which was comparable to the contralateral side (10 mm, p = 0.103). At follow-up the CC distance increased to 13 mm (p = 0.0001).

CONCLUSION

AC-joint stabilisation with a single tunnel reconstruction using a second-generation implant results in good to excellent clinical results with high patient satisfaction. The additional AC augmentation improves stability in horizontal instable AC-joints and is recommended in all high-grade AC joint stabilisations. Nonetheless, reduction was slightly lost over time due to an elongation or suture failure of the coraco-clavicular fixation.

LEVEL OF EVIDENCE

IV.

Does Weaver-Dunn procedure have a role in chronic acromioclavicular dislocations? A meta-analysis

Background

In treatment of chronic acromioclavicular (AC) joint dislocations, both the Weaver–Dunn procedure (WD) and CC ligament reconstruction (CCR) are recommended options due to the low possibility of healing of the coracoclavicular (CC) ligaments. The aim of this review was to determine whether CCR will yield favorable clinical and radiographic outcomes in the treatment of chronic AC dislocations.

Method

The Cochrane Library, EMBASE, and PubMed databases were searched for literature on chronic AC dislocations from data inception to June 30, 2021. Patient data were pooled using standard meta-analytic approaches. The Cochrane-Mantel–Haenszel method and variance-weighted means were used to analyze the outcomes. The Review Manager version 5.3 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) was used to calculate the heterogenicity, mean difference, and relative risk (RR) for all outcomes in the meta-analysis.

Results

The current analysis included four trials on this topic, and all AC joint dislocations were classified as Rockwood types III to VI. The pooled data showed that the CCR group had significantly better post-operative American Shoulder and Elbow Surgeons Shoulder (ASES) scores, Oxford Shoulder Scores (OSSs), and Nottingham Clavicle Scores (NCSs) than the WD group, with a significant difference (p < 0.001, p = 0.020, and p < 0.001, respectively). In terms of the post-operative Constant-Murley Scores (CMSs), there were no significant differences between the CCR group and the WD group (p = 0.100). The CCR group had significantly better post-operative abduction and flexion of the index shoulder than the WD group (p < 0.001 and p < 0.001, respectively). In terms of radiological outcomes, the post-operative coracoclavicular distance (CCD) with a 10 kg load was smaller in the CCR group compared to that in the WD group (p < 0.001). The overall surgical wound infection rate was 11.6% in the WD group and 12.9% in the CCR, respectively (p = 0.82).

Conclusion

The CCR group had better clinical outcome scores in the ASES, OOS, NCS, abduction, flexion, and external rotation than the WD group. In terms of radiological outcomes, the CCR group showed less displacement in weight-loaded post-CCD than the WD group, which indicated that the CCR provided more stability and resistance to deformation forces.

Low rate of substantial loss of reduction immediately after hardware removal following acromioclavicular joint stabilization using a suspensory fixation system

PURPOSE

To evaluate immediate loss of reduction in patients undergoing hardware removal after arthroscopically assisted acromioclavicular (AC) joint stabilization using a high-tensile suture tape suspensory fixation system and to identify risk factors associated with immediate loss of reduction.

MATERIALS AND METHODS

Twenty-two consecutive patients with a mean age of 36.4 ± 12.6 years (19-56), who underwent hardware removal 18.2 ± 15.0 months following arthroscopically assisted stabilization surgery using a suspensory fixation system for AC joint injury between 01/2012 and 01/2021 were enrolled in this retrospective monocentric study. The coracoclavicular distance (CCD) as well as the clavicular dislocation/acromial thickness (D/A) ratio were measured on anterior-posterior radiographs prior to hardware removal and immediately postoperatively by two independent raters. Loss of reduction, defined as 10% increase in the CCD, was deemed substantial if the CCD increased 6 mm compared to preoperatively. Constitutional and surgical characteristics were assessed in a subgroup analysis to detect risk factors associated with loss of reduction.

RESULTS

Postoperatively, the CCD significantly increased from 12.6 ± 3.7 mm (4.8-19.0) to 14.5 ± 3.3 mm (8.7-20.6 mm) (p < 0.001) while the D/A ratio increased from 0.4 ± 0.3 (- 0.4-0.9) to 0.6 ± 0.3 (1.1-0.1) (p = 0.034) compared to preoperatively. In 10 cases (45%), loss of reduction was identified, while a substantial loss of reduction (> 6 mm) was only observed in one patient (4.5%). A shorter time interval between index stabilization surgery and hardware removal significantly corresponded to immediate loss of reduction (11.0 ± 5.6 vs. 30.0 ± 20.8 months; p = 0.007), as hardware removal within one year following index stabilization was significantly associated with immediate loss of reduction (p = 0.027; relative risk 3.4; odds ratio 11.67).

CONCLUSIONS

Substantial loss of reduction after hardware removal of a high-tensile suture tape suspensory fixation system was rare, indicating that the postoperative result of AC stabilization is not categorically at risk when performing this procedure. Even though radiological assessment of the patients showed a statistically significant immediate superior clavicular displacement after this rarely required procedure, with an increased incidence in the first year following stabilization, this may not negatively influence the results of ACJ stabilization in a clinically relevant way.

LEVEL OF EVIDENCE

IV.

Concomitant Acromioclavicular and Coracoclavicular Ligament Reconstruction with a Duo-Figure-8 Autogenic Graft Wrapping Technique for Treating Chronic Acromioclavicular Separation

Backgroud

Coracoacromial ligament transfer is the traditional procedure for treating chronic acromioclavicular separation, but it is significantly inferior to ligament reconstruction according to biomechanical and clinical studies. However, ligament reconstruction carries the risk of complications of graft loosening and peri-tunnel fractures. Currently, there is no ligament reconstruction procedure optimal for preventing such complications. The purpose of this study was to describe and retrospectively analyze the clinical and radiological outcomes of a “duo-figure-8” autogenic graft wrapping technique, which was used to concomitantly reconstruct the acromioclavicular and coracoclavicular ligaments.

Methods

Preoperative, immediate postoperative, and final follow-up oputcomes were evaluated in 10 enrolled patients. Radiographic outcomes were indicated by the bilateral difference of the coracoclavicular distance (CCD) and overlapping length of the acromioclavicular joint (OLac). Quality of reduction was classified into 4 grades according to bilateral CCD difference into overreduction (< 0 mm), anatomic reduction (0–4 mm), partial loss of reduction (4–8 mm), and recurrent dislocation (> 8 mm). Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) and Constant scores.

Results

The mean side-to-side differences for CCD were 11.9 mm (preoperative), −0.1 mm (immediate postoperative), and 3.4 mm (final follow-up); those for OLac were 9.4 mm (preoperative) and 2.7 mm (final follow-up). CCD and OLac outcomes significantly improved at final follow-up (p < 0.05). At the immediate postoperative stage, 6 and 4 patients had overreduction and anatomic reduction, respectively. At final follow-up, 7 and 3 patients had anatomic reduction and partial loss of reduction, respectively. The magnitude of improvement of ASES scores for patients with anatomic reduction and partial loss of reduction (p = 0.20) was 18.1 and 20.0, respectively. The magnitude of improvement of Constant scores in patients with anatomic reduction and partial loss of reduction (p = 0.25) was 19.9 and 22.3, respectively.

Conclusions

The technique yielded acceptable functional outcomes in patients with anatomic reduction or partial loss of reduction. The “duo-figure-8” wrapping method—a single autogenic tendon graft passing beneath the coracoid process with a tendon-knot fixation over the distal clavicle and looping around the acromion intramedullary—did not increase the risk of peri-tunnel fractures over the clavicle, coracoid process, or acromion.

Anatomic reconstruction of the acromioclavicular joint provides the best functional outcomes in the treatment of chronic instability

PURPOSE

To systematically review the outcomes of surgical treatments of chronic acromioclavicular joint dislocation.

METHODS

Studies were identified by electronic databases (Ovid, PubMed). All studies reporting functional and radiological outcomes of surgical treatments of chronic acromioclavicular joint dislocations were included. Following data were extracted: authors and year, study design, level of evidence, number of patients, age, classification of acromioclavicular joint dislocation, time to surgery, surgical technique, follow-up, clinical and imaging outcomes, complications and failures. Descriptive statistics was used, when a data pooling was not possible. Comparable outcomes were pooled to generate summary outcomes reported as frequency-weighted values. Quality appraisal was assessed through the MINORS checklist.

RESULTS

Fourty-four studies were included for a total of 1020 shoulders. Mean age of participants was 38 years. Mean follow-up was 32.9 months. Arthroscopic techniques showed better results than open approach (p < 0.0001). Synthetic reconstructions demonstrated better functional outcomes compared to internal fixation and biologic techniques (p < 0.0001). Among biologic techniques, combined coracoclavicular and acromioclavicular ligaments reconstruction showed better Constant (p = 0.0270) and ASES (p = 0.0113) scores compared to isolated coracoclavicular ligaments reconstruction; anatomic biologic non-augmented graft reconstruction showed better Constant (p < 0.0001), VAS (p < 0.0001) and SSV (p = 0.0177) results compared to augmented techniques. No differences in functional outcomes could be found between anatomic biologic non-augmented graft versus synthetic reconstructions. Overall, methodological quality of the included studies was low.

CONCLUSION

Anatomic reconstructions, both synthetic and biologic, showed the best functional results.

LEVEL OF EVIDENCE

IV.

Allo- and autografts show comparable outcomes in chronic acromioclavicular joint reconstruction: a systematic review

PURPOSE

The aim of this review was to compare clinical and radiological outcome of acromio-clavicular joint reconstruction with allografts versus autografts.

METHODS

The PubMed, MEDLINE, The Cochrane Library and WEB OF SCIENCE databases were searched in accordance with the PRISMA guidelines until February 2020 using the terms: 'coracoclavicular' OR 'coraco-clavicular' OR 'acromioclavicular' OR 'acromio-clavicular joint', AND 'reconstruction'. All studies reporting on clinical and radiological outcome as well as complications after ACJ reconstruction using allo- and/or autografts were included.

RESULTS

A total of 29 articles, including 2 prospective and 27 retrospective studies, involving 622 patients, reconstructed with either allo- (n = 360) or auto-grafts (n = 262), for acromio-clavicular joint instability were identified and included in this review. The majority of studies had low sample sizes (66.7% below n = 20), were retrospective (93.3%), with short-term follow-ups (average 26.2 ± 12.6 months; range 6-186). The study with the largest sample size (n = 128) did not report clinical outcome. A comparison between allo- and auto-graft showed no significant differences regarding age, gender, and follow-up times. Clinical outcome was comparable in both groups, loss of reduction (LOR) and complication rates were higher in the allograft group. Overall a reduction of LOR was shown if additional horizontal stabilization was performed. Also a higher LOR and revision rate was documented in allografts without suture or suture-tape augmentation. The use of more clavicular drill-holes correlated with a higher frequency of fracture.

CONCLUSIONS

A systematic review of the available peer-reviewed literature addressing allograft and autograft reconstruction of unstable coracoclavicular ligaments shows that the published studies are generally of low quality with low levels of evidence. The published literature shows no significant difference in clinical outcomes between the use of autografts or allografts in ACJ reconstruction surgery. Surgical techniques utilizing additional horizontal stabilization may contribute to lower rates of LOR. In cases where allograft tissue is used for ACJ reconstruction the use of suture/tape augmentation may reduce LOR rates as well as revision rates.

LEVEL OF EVIDENCE

III.

Arthroscopic-Assisted Coracoclavicular Ligament Reconstruction: Clinical Outcomes and Return to Activity at Mean 6-Year Follow-Up

PURPOSE

To report clinical and functional outcomes including return to preinjury activity level following arthroscopic-assisted coracoclavicular (CC) ligament reconstruction (AA-CCR) and to determine associations between return to preinjury activity level, radiographic outcomes, and patient-reported outcomes following AA-CCR.

METHODS

A institutional registry review of all AA-CCR using free tendon grafts from 2007 to 2016 was performed. Clinical assessment included Single Assessment Numeric Evaluation (SANE) score and return to preinjury activity level at final follow-up. Treatment failure was defined as (1) revision acromioclavicular stabilization surgery, (2) unable to return to preinjury activity level, or (3) radiographic loss of reduction (RLOR, >25% CC distance compared with contralateral side). SANE scores, return to activity, and RLOR were compared between patients within each category of treatment failure, by grade of injury, and whether concomitant pathology was treated.

RESULTS

There were 88 patients (89.8% male) with mean age of 39.6 years and minimum 2-year clinical follow-up (mean 6.1 years). Most injuries were Rockwood grade V (63.6%). Mean postoperative SANE score was 86.3 ± 17.5. Treatment failure occurred in 17.1%: 8.0% were unable to return to activity, 5.7% had RLOR, and 3.4% underwent revision surgery due to traumatic reinjury. SANE score was lower among patients who were unable to return to activity compared with those with RLOR and compared with nonfailures (P = .0002). There were no differences in revision surgery rates, return to activity, or SANE scores according to Rockwood grade or if concomitant pathology was treated.

CONCLUSIONS

AA-CCR with free tendon grafts resulted in good clinical outcomes and a high rate of return to preinjury activity level. RLOR did not correlate with return to preinjury activity level. Concomitant pathology that required treatment did not adversely affect outcomes. Return to preinjury activity level may be a more clinically relevant outcome measure than radiographic maintenance of acromioclavicular joint reduction.

LEVEL OF EVIDENCE

IV (Case Series).

Functional and Radiographic Outcomes of Intraoperatively Decreasing the Coracoclavicular Distance to 50% of the Unaffected Side in Stabilization of Acute Acromioclavicular Joint Injury: A Retrospective Evaluation

Background:

The postoperative failure rate of acromioclavicular (AC) joint fixation using the coracoclavicular (CC) stabilization technique is high. Studies have reported that compared with normal intraoperative anatomic reduction, intraoperative overreduction of the AC joint is more successful in achieving a satisfactory anatomic radiographic outcome at 1- to 2-year follow-up.

Purpose:

To evaluate the functional and radiographic outcomes and complications in patients with acute AC joint injury who underwent combined CC stabilization and AC capsular repair in which the CC distance was intraoperatively decreased to 50% of the unaffected side.

Study Design:

Case series; Level of evidence, 4.

Methods:

In this retrospective study, we collected and analyzed the data of patients with an acute AC joint injury (Rockwood type 5) who underwent combined CC stabilization and AC capsular repair during which the CC distance was decreased 50% compared with the unaffected side. At 2-year follow-up, we evaluated functional outcomes (American Shoulder and Elbow Surgeons [ASES] score), radiographic outcomes (alignment of the AC joint in the vertical and horizontal planes, tunnel widening), and complications (infection, clavicular fracture).

Results:

The study included 20 patients with a mean ± SD age of 42.20 ± 10.10 years. The mean follow-up period was 33.75 ± 11.50 months. At the 2-year follow-up, the mean ASES score was 95.13 ± 5.61. The overreduction alignment, anatomic alignment, and loss reduction alignment rates were 0% (0/20 patients), 95% (19/20 patients), and 5% (1/ 20 patients), respectively. No statistically significant difference was found in the mean CC distance between the affected and unaffected sides on radiographic evaluation. The mean medial clavicular tunnel width and lateral clavicular tunnel width were 5.03 ± 0.68 mm and 4.47 ± 0.67 mm, respectively. None of the patients experienced fractures or infections.

Conclusion:

Excellent functional and radiographic outcomes and no complications were seen at 2-year follow-up in patients with acute AC joint injury who underwent combined CC stabilization and AC capsular repair with the CC distance intraoperatively decreased to 50% of the unaffected side.

Early clinical results of minimally invasive coracoclavicular ligament reconstruction can be maintained at a minimum of five years' follow-up

AIMS

There is a lack of long-term data for minimally invasive acromioclavicular (AC) joint repair. Furthermore, it is not clear if good early clinical results can be maintained over time. The purpose of this study was to report long-term results of minimally invasive AC joint reconstruction (MINAR) and compare it to corresponding short-term data.

METHODS

We assessed patients with a follow-up of at least five years after minimally invasive flip-button repair for high-grade AC joint dislocation. The clinical outcome was evaluated using the Constant score and a questionnaire. Ultrasound determined the coracoclavicular (CC) distance. Results of the current follow-up were compared to the short-term results of the same cohort.

RESULTS

A total of 50 patients (three females, 47 males) were successfully followed up for a minimum of five years. The mean follow-up was 7.7 years (63 months to 132 months). The overall Constant score was 94.4 points (54 to 100) versus 97.7 points (83 to 100) for the contralateral side showing a significant difference for the operated shoulder (p = 0.013) The mean difference in the CC distance between the operated and the contralateral shoulder was 3.7 mm (0.2 to 7.8; p = 0.010). In total, 16% (n = 8) of patients showed recurrent instability. All these cases were performed within the first 16 months after introduction of this technique. A total of 84% (n = 42) of the patients were able to return to their previous occupations and sport activities. Comparison of short-term and long-term results revealed no significant difference for the Constant Score (p = 0.348) and the CC distance (p = 0.974).

CONCLUSION

The clinical outcome of MINAR is good to excellent after long-term follow-up and no significant differences were found compared to short-term results. We therefore suggest this is a reliable technique for surgical treatment of high-grade AC joint dislocation. Cite this article: Bone Joint J 2020;102-B(7):918-924.

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.

Systematic review of the treatment of acromioclavicular joint disruption comparing number of tunnels and graft type

BACKGROUND

The management of high-grade acromioclavicular separations remains unclear. The surgical interventions have shifted to more anatomic, less invasive techniques. The purpose of this study was to systematically review the outcomes and complications of anatomic coracoclavicular ligament reconstruction using a tendon graft.

METHODS

Twenty-one studies (n = 460 patients) met the criteria for inclusion. A double clavicle tunnel tendon graft construct was used in 348 patients (75.7%), whereas a single clavicle tunnel technique was used in 112 patients (24.3%). No significant difference in loss of reduction was found between the 2 techniques. Of 460 patients, 96 (20.9%) demonstrated some form of radiographic displacement at the final follow-up. The overall complication rate was 21.3% (98 of 460), and a higher complication rate was found in the double clavicle tunnel technique (P < .001). The overall reoperation rate was 7.6% (37 of 460). The most common reason for reoperation was clavicle fracture (8 of 37). There was a statistically significant increase in reoperation when allograft was used (P = .003).

CONCLUSION

The results of this study suggest that despite newer techniques, approximately 20% of patients develop loss of reduction and/or experience a surgical complication. Attempts to minimize trauma to the clavicle and use autograft tendon may reduce the risk of reoperation.

Horizontal Instability of the Acromioclavicular Joint: A Systematic Review

BACKGROUND

Injuries to the acromioclavicular (AC) joint are common and should be suspected in patients who have shoulder pain in the region of the acromion and clavicle. Injuries to the AC ligament can cause horizontal instability and are often neglected or underdiagnosed, which can lead to poor patient outcomes.

PURPOSE

To perform a systematic review of the literature on the diagnosis and treatment of horizontal instability of the AC joint.

STUDY DESIGN

Systematic review.

METHODS

The authors performed a systematic review using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed and EMBASE were searched for studies that investigated diagnosis, treatment, and failure of operative management of acute and chronic AC separations. Studies that did not specifically evaluate AC joint injuries, were not written in English, or were specific only to vertical instability of the AC joint were excluded.

RESULTS

Overall, 23 articles met the inclusion criteria and were therefore included in this systematic review. Diagnosing horizontal AC instability is difficult using plain radiographs; dynamic views were shown in some cases to better detect horizontal instability than with static views. More than 60 procedures for treating AC joint injuries have been published, but many focus on vertical rather than horizontal instability. Modifications to current surgical procedures to incorporate reconstruction of the horizontal component showed improved patient outcomes. Such modifications included additional AC joint suture cord cerclage, combined AC and coracoclavicular ligament reconstruction, and the Twin Tail TightRope triple button technique. Failure after surgical stabilization of AC joint separation has been reported to occur in 15% to 80% of cases.

CONCLUSION

No consensus is available regarding the best practices for diagnosis, evaluation, and treatment of acute or chronic horizontal instability of the AC joint. Moreover, horizontal instability injuries are often neglected or poorly understood, making diagnosis difficult, which may lead to high complication rates and failure after surgical stabilization.

Sex-Based Differences in Optimal Tunnel Placement for Acromioclavicular Joint Reconstruction

BACKGROUND

Tunnel placement is important for outcomes after acromioclavicular (AC) joint reconstruction, yet little has been written on sex-based differences in optimal tunnel positioning.

HYPOTHESIS

No sex-based or anatomic differences will be found in ideal tunnel position based on radiographic measurements.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

The records of 2382 patients were retrospectively examined for clavicle radiographs over a 20-year period. A random set of radiographs were reviewed until 200 radiographs from each sex met inclusion criteria per a priori power analysis. Anteroposterior clavicle radiographs were used to collect (1) length from lateral clavicle to lateral coracoid (LCLC), (2) length from lateral clavicle to medial coracoid (LCMC), (3) clavicle length (CL), and (4) clavicular depth at the midcoracoid (MCCD). The Student t test was used to compare differences between male and female patients. The Pearson correlation coefficient was used to measure linear correlations. Variables with a P < .1 were included in a multiple regression model.

RESULTS

The cohort included 200 men and 200 women. LCLC and LCMC were significantly greater for men than for women (P < .0001). Clavicle length was significantly correlated with LCLC (r = 0.63; P < .0001) and LCMC (r = 0.74; P < .0001). MCCD was significantly correlated with LCLC (r = 0.32; P < .0001) and LCMC (r = 0.43; P < .0001). The approximate placement for the trapezoid tunnel was found to be 22.1 mm in women and 26.6 mm in men. The approximate placement for the conoid tunnel was found to be 40 mm in women and 46.6 mm in men. The ratios (LCLC:CL and LCMC:CL) were also significantly different between female and male patients. The LCLC:CL was 0.144 in women and 0.154 in men (P < .0001). The LCMC:CL was 0.261 in women and 0.271 in men (P < .0006).

CONCLUSION

Significant sex-based differences are found in the position of the coracoid relative to the lateral edge of the clavicle. Coracoid position relative to the lateral edge of the clavicle is correlated with anatomic parameters, most strongly with clavicle length.

Anatomic and non-anatomic reconstruction improves post-operative outcomes in chronic acromio-clavicular instability: a systematic review

PURPOSE

To systematize the surgical outcomes of anatomic and non-anatomic reconstruction in patients with chronic acromio-clavicular joint (ACJ) instability and determine which technique is superior.

METHODS

This review was conducted according to the PRISMA guidelines. PubMed and Cochrane Library databases were searched up to April 30th, 2018 for original articles that assessed the outcomes of one or more surgical techniques of anatomic and non-anatomic reconstruction in patients with chronic ACJ instability. The Methodological Index for Non-randomized Studies (MINORS) was used to assess study quality. Pre-to-post meta-analysis was performed for both anatomic and non-anatomic reconstructions.

RESULTS

Twenty-eight studies were included comprising 799 patients (mean age of 36.6 years old and 84% males) with a mean follow-up of 34.6 months (range 13 to 74). Surgical techniques included anatomic (tendinous or synthetic grafts/constructs) and non-anatomic reconstruction (Weaver-Dunn or Modified Weaver-Dunn, conjoined tendon transfer, or temporary hook plate). There were significant pre-to-post improvements on the constant score with an average improvement ranging from 11.1 to 50.7 (p < 0.01). Average failure rate was 7.6% (7.5% for anatomic and 8.5% for non-anatomic reconstruction). Non-comparative studies had a mean MINORS score of 9 points (out of 16) and comparative studies 17 (out of 24) with excellent interrater agreement (k = 0.910).

CONCLUSION

Both anatomic and non-anatomic ACJ reconstructions provide significant post-operative improvements, but definitive conclusions on optimal technique remain elusive. Notwithstanding, comparative studies support the use of anatomic ACJ reconstruction which should be preferably used. However, until superiority is demonstrated by robust studies, surgeons should supplement their decision-making with experience and patient preference.

LEVEL OF EVIDENCE

IV.

Acromioclavicular joint augmentation at the time of coracoclavicular ligament reconstruction fails to improve functional outcomes despite significantly improved horizontal stability

PURPOSE

Acromioclavicular joint reconstruction is a well-established and frequently performed procedure. Recent scientific and commercial interest has led to a drive to develop and perform surgical techniques that more reliably restore horizontal stability in order to improve patient outcomes. The aim of this systematic review was to evaluate the biomechanical evidence for procedures directed at restoring horizontal stability and determine whether they are associated with superior clinical results when compared to well-established procedures.

METHODS

A review of the online databases Medline and EMBASE was conducted in accordance with the PRISMA guidelines on the 23rd December 2017. Biomechanical and clinical studies reporting either static or dynamic horizontal displacement following acromioclavicular joint reconstruction (Coracoclavicular reconstruction or Weaver-Dunn) were included. In addition, biomechanical and clinical studies reporting outcomes after additional augmentation of the acromioclavicular joint were included. The studies were appraised using the Methodological index for non-randomised studies tool.

RESULTS

The search strategy identified 18 studies eligible for inclusion: six biomechanical and 12 clinical studies. Comparative biomechanical studies demonstrated that acromioclavicular augmentation provided significantly increased horizontal stability compared to the coracoclavicular reconstruction and Weaver-Dunn procedure. Comparative clinical studies demonstrated no significant differences between coracoclavicular reconstruction with and without acromioclavicular augmentation in terms of functional outcomes (American Shoulder and Elbow Surgeon and Constant score), complication or revision rates. However, one comparative study did demonstrate an improvement in Taft (p = 0.018) and Acromioclavicular Joint Instability scores (p = 0.0001) after acromioclavicular augmentation.

CONCLUSION

In conclusion, coracoclavicular reconstruction with augmentation of the acromioclavicular joint has been shown to provide improved horizontal stability in both biomechanical and clinical studies compared to isolated coracoclavicular reconstruction. However, comparative studies have shown no clinical advantage with respect to American Shoulder and Elbow Surgeon or Constant scores and, therefore, the results of this systematic review do not support acromioclavicular augmentation in routine clinical practice.

LEVEL OF EVIDENCE

IV.

Surgical management of chronic high-grade acromioclavicular joint dislocations: a systematic review

BACKGROUND

To date, no gold-standard technique exists for the treatment of chronic acromioclavicular joint (ACJ) instability. We systematically reviewed the clinical results of 3 main categories of ACJ reconstruction for high-grade chronic instability.

METHODS

A literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The inclusion criteria were clinical studies involving patients with ACJ instability (Rockwood grades III-VI) for at least 6 weeks, managed with ACJ stabilization, with a minimum 1-year follow-up. Depending on the surgical technique, patients were divided into 1 of 3 groups: nonbiological fixation between the coracoid and clavicle, for example, suture loops and synthetic ligaments (group 1); biological reconstruction of the coracoclavicular ligaments, for example, allograft or autograft ligament reconstruction (group 2); and ligament and/or tendon transfer, for example, the Weaver-Dunn procedure (group 3). Patient demographic characteristics, functional scores, radiographic outcomes, and complications were compared.

RESULTS

Two independent investigators reviewed 960 articles. A total of 27 studies met the inclusion criteria, comprising 590 patients divided into 1 of 3 groups. The complication rates were similar among the 3 groups: 15% for nonbiological fixation, 15% for biological reconstruction, and 17% for ligament and/or tendon transfer, with failure rates of 8%, 7%, and 5%, respectively. In terms of functional results, the mean Constant score was 87.2 points for nonbiological fixation (n = 89), 92.4 points for biological reconstruction (n = 86), and 87.4 points for ligament and/or tendon transfer (n = 49).

CONCLUSION

On comparison of the results of 3 different ACJ reconstruction methods, all techniques showed similar complication rates. Among the level II studies, ACJ reconstruction with a tendon graft showed superior results.

Current Concepts in the Operative Management of Acromioclavicular Dislocations: A Systematic Review and Meta-analysis of Operative Techniques

BACKGROUND

Acromioclavicular (AC) instability is a frequent injury affecting young and athletic populations. Symptomatic, high-grade dislocations may be managed by a myriad of operative techniques that utilize different grafts to achieve reduction. Comparative data are lacking on the ability of these techniques to achieve excellent patient outcomes and stable AC reduction and to minimize complications.

PURPOSE

To systematically review the outcomes and complications of different techniques of AC joint reconstruction.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The MEDLINE, Scopus, Embase, and Cochrane Library databases were accessed to perform a systematic review of the scientific literature from 2000 to 2018 using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria with the following keywords: "acromioclavicular" and "reconstruction." Included articles were evaluated for loss of reduction, complication rate, revision rate, and change in coracoclavicular distance. Articles were stratified by graft and surgical material used: suture only, Endobutton with suture, TightRope, GraftRope, synthetic artificial ligament, tendon graft, and Weaver-Dunn coracoacromial ligament transfer. These outcomes were pooled using a random-effects model and stratified by surgical technique and arthroscopic versus open reconstruction.

RESULTS

Fifty-eight articles were included in the analysis, with 63 homogeneous populations composed of 1704 patients. The mean age was 37.1 years (range, 15-80 years) with a mean follow-up of 34.3 months (range, 1.5-186 months). The overall failure rate was 20.8% (95% CI, 16.9%-25.2%). The overall pooled complication rate was 14.2% (95% CI, 10.5%-18.8%). The most common complications were infection (6.3% [95% CI, 4.7%-8.2%]), fracture to the coracoid or distal clavicle (5.7% [95% CI, 4.3%-7.6%]), and hardware/button failure (4.2% [95% CI, 3.1%-5.8%]). There were no differences between arthroscopic and open techniques in regard to loss of reduction (P = .858), overall complication rate (P = .774), and revision rate (P = .390). Open surgery had a greater rate of clavicular/coracoid fractures than arthroscopic surgery (P = .048). Heterogeneity, best assessed from the pooled loss of reduction, was measured as I² = 64.0%.

CONCLUSION

Open and arthroscopic AC joint reconstruction techniques have no differences in loss of reduction, the complication rate, and the revision rate based on the available literature. Complications are significant, and profiles vary between surgical techniques, which should be evaluated in the decision making of selecting the technique.

Primary versus revision arthroscopically-assisted acromio- and coracoclavicular stabilization of chronic AC-joint instability

BACKGROUND

A gracilis tendon autograft with TightRope-augmentation can be used for arthroscopically-assisted acromioclavicular (AC)- and coracoclavicular (CC-)stabilization of chronic bidirectional AC-joint instability after failed primary treatment. The impact of failed initial treatment on postoperative outcome is unclear. Hence, the purpose of this study was to evaluate it.

METHODS

Twenty-seven of 38 patients suffering from chronic AC-joint instability after either failed conservative (group 1) or surgical treatment (group 2) treated in the above-mentioned technique were finally included in this study. The Subjective Shoulder Value, the Constant Score, the Taft Score and the Acromioclavicular Joint Instability Score were used for clinical evaluation. Bilateral anteroposterior stress radiographs and bilateral Alexander views were obtained for radiological evaluation.

RESULTS

14 patients of group 1 [3f/11m; median age 47.6 (range 20.9-57.4) years] could be evaluated after a median follow-up of 24.3 (range 20-31.2) months and 13 patients of group 2 [6f/7m; median age 44.9 (range 24.9-61.0) years] were available after a median follow-up of 28.8 (range 20-33) months. Comparison of clinical score results revealed no significant differences between both groups. The median CC-difference showed no significant difference between the groups [group 1 0.8 (0-10.5) mm, group 2 0.9 (0-4.3) mm].

CONCLUSION

AC- and CC-stabilization of chronic bidirectional AC-joint instability using a gracilis tendon autograft with TightRope-augmentation can be recommended after failed conservative and surgical treatment.

STUDY DESIGN

Retrospective cohort study; Level of evidence III.

All-Arthroscopic Reconstruction of Severe Chronic Acromioclavicular Joint Dislocations

PURPOSE

To report the outcomes of all-arthroscopic coracoclavicular (CC) ligament reconstruction and simultaneous diagnosis and treatment of glenohumeral pathologies in patients with symptomatic, chronic (>6 weeks), complete (Rockwood type III-V) acromioclavicular joint (ACJ) separations.

METHODS

We prospectively followed up 57 consecutive patients treated arthroscopically for chronic Rockwood type III (n = 11), type IV (n = 19), and type V (n = 27) ACJ dislocations. Previous ACJ surgery failed in 11 (19%). The mean delay between injury and surgery was 39 months (range, 6 months to 17 years). The mean age at surgery was 42 years (range, 19-71 years). After glenohumeral exploration, an arthroscopic modified Weaver-Dunn procedure with CC suture button fixation (Twinbridge) was performed. The CC reduction and tunnel position were analyzed with radiographs and computed tomography. The mean follow-up period was 36 months (range, 12-72 months).

RESULTS

Intra-articular pathology was treated arthroscopically in 27 patients (48%): 17 labral tears, 8 rotator cuff tears (3 partial and 5 complete), and 15 biceps lesions (4 SLAP lesions and 11 subluxations). At last follow-up, 7 patients (12%) experienced recurrent ACJ instability: 2 frank dislocations (1 trauma and 1 infection) and 5 ACJ subluxations. There was no significant correlation between subluxation and clinical outcome. The rate of recurrent ACJ instability was significantly higher in patients with higher-grade ACJ dislocations (P < .01) and/or previous failed surgery (P < .001). Recurrent subluxation was observed in 3 cases of lateral migration of the coracoid button with lateral tunnel placement, as well as 2 cases of anterior migration of the clavicular button with anterior tunnel placement. The Constant score increased from 67 (range, 28-89) to 85.5 (range, 66-100), and the mean Subjective Shoulder Value increased from 54% to 85% (P < .001). At last follow-up, 95% of patients (54 of 57) were satisfied.

CONCLUSIONS

All-arthroscopic treatment allows successful CC ligament reconstruction and simultaneous diagnosis and treatment of frequently associated (48%) glenohumeral lesions. Higher-grade ACJ dislocations, previous ACJ surgery, and misplacement of bone tunnels are risk factors for recurrent instability.

LEVEL OF EVIDENCE

Level IV, case series.

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.

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.

Acromioclavicular joint dislocation: a Dog Bone button fixation alone versus Dog Bone button fixation augmented with acromioclavicular repair-a finite element analysis study

BACKGROUND

Suspension suture button fixation was frequently used to treat acromioclavicular joint (ACJ) dislocation. However, there were many studies reporting about complications and residual horizontal instability after fixation. Our study compared the stability of ACJ after fixation between coracoclavicular (CC) fixation alone and CC fixation combined with ACJ repair by using finite element analysis (FEA).

MATERIALS AND METHODS

A finite element model was created by using CT images from the normal shoulder. The model 1 was CC fixation with suture button alone, and the model 2 was CC fixation with suture button combined with ACJ repair. Three different forces (50, 100, 200 N) applied to the model in three planes; inferior, anterior and posterior direction load to the acromion. The von Mises stress of the implants and deformation at ACJs was recorded.

RESULTS

The ACJ repair in the model 2 could reduce the peak stress on the implant after applying the loading forces to the acromion which the ACJ repair could reduce the peak stress of the FiberWire at suture button about 90% when compared to model 1. And, the ACJ repair could reduce the deformation of the ACJ after applying the loading forces to the acromion in both vertical and horizontal planes.

CONCLUSION

This FEA supports that the high-grade injuries of the ACJ should be treated with CC fixation combined with ACJ repair because this technique provides excellent stability in both vertical and horizontal planes and reduces stress to the suture button.

Surgical treatment of acute type V acromioclavicular joint dislocations in professional athletes: an anatomic ligament reconstruction with synthetic implant augmentation

BACKGROUND

Most acromioclavicular (AC) joint injuries occur in men in their third decade of life during high-speed or high-impact body contact sports. The management of acute complete AC joint dislocation is surgical. Current surgical techniques include anatomic reconstruction of the main restraints of the AC joint and aim to improve functional outcomes and to reduce the complication rate.

METHODS

We present 10 cases of acute type V AC joint dislocation in professional athletes treated surgically with anatomic reconstruction of the coracoclavicular and AC ligaments and augmentation with the use of a synthetic polyester tape. The minimum follow-up of the patients was 2 years (mean, 48 months; range, 24-86 months). The postoperative functional outcome was assessed at 1 year and 2 years using the Constant-Murley, American Shoulder and Elbow Surgeons, and modified University of California-Los Angeles scoring systems.

RESULTS

In all cases, the postoperative scores were significantly improved (P < .005 in all comparisons with the preoperative scores), and all patients returned to their preinjury high level of activity 6 months postoperatively. Radiographs at 1 month and 6 months revealed the maintenance of reduction. There were no complications.

CONCLUSION

According to the results of our series of patients, demanding cases of acute AC joint dislocation Rockwood type V, in professional athletes, require anatomic fixation of both coracoclavicular and AC ligaments for return to sports as soon as possible and at the preinjury level of performance.

Arthroscopic treatment of acromioclavicular dislocation

A thorough understanding of biomechanical function of both acromioclavicular (AC) and coracoclavicular (CC) ligaments, stimulated surgeons to repair high-grade AC dislocation using arthroscopic technique. This technique necessitates a clear understanding of shoulder anatomy, especially of the structures in proximity to the clavicle and coracoid process and experiences in arthroscopic surgery. The follow case describes an arthroscopic technique used to treat AC dislocation in young man 30 years old, who suffered an injury at right shoulder. Results were similar to those obtained using open surgery and this encouraged us to continue utilization of this method. As a conclusion, arthroscopic treatment of AC separation is one of the best options as surgical treatment. Early results suggested that immediate anatomic reduction of an acute AC separation usually provides satisfactory clinical results at intermediate-term follow-up.

[Chronic acromioclavicular joint injury of Rockwood V type with concomitant chronic anterior sternoclavicular instability]

Bipolar dislocation of the clavicle is rare. In the literature, every reported bipolar dislocation of the clavicle is caused by a traumatic injury with loss of function of the affected shoulder. Currently, there is no recommendation to treat. A conservative treatment can be tried first to achieve adequate shoulder function. If this cannot be achieved, surgical treatment will be indicated. In the literature, many options for surgical treatment are described. This article presents a case of a chronic Rockwood V injury with chronic anterior sternoclavicular joint instability. The special feature of this case was the arthroscopically assisted stabilization of the acromioclavicular joint (ACJ) with the ipsilateral semitendinosus tendon graft and the open stabilization of the sternoclavicular joint (SCJ) with the ipsilateral gracilis tendon graft. A lateral fracture of the clavicle in the course of the postoperative treatment was treated with a plate osteosynthesis. At follow-up after six months, the postoperative shoulder function was restored. The ACJ and the SCJ were stable in clinical and radiographic examination. This case report shows the first surgical treatment using two tendon grafts for combined stabilization of the ACJ and SCJ.

Concomitant glenohumeral pathologies associated with acute and chronic grade III and grade V acromioclavicular joint injuries

PURPOSE

The purpose of this study was to identify the risk of concomitant glenohumeral pathologies with acromioclavicular joint injuries grade III and V.

METHODS

Patients who underwent arthroscopically-assisted stabilization of acromioclavicular joint injuries grade III or grade V between 01/2007 and 12/2015 were identified in the patient databases of two surgical centres. Gender, age at index surgery, grade of acromioclavicular joint injury (Rockwood III or Rockwood V), and duration between injury and index surgery (classified as acute or chronic) were of interest. Concomitant glenohumeral pathologies were noted and their treatment was classified as debridement or reconstructive procedure.

RESULTS

A total of 376 patients (336 male, 40 female) were included. Mean age at time of arthroscopic acromioclavicular joint reconstruction surgery was 42.1 ± 14.0 years. Overall, 201 patients (53%) had one or more concomitant glenohumeral pathologies. Lesions of the biceps tendon complex and rotator cuff were the most common. Forty-five patients (12.0%) had concomitant glenohumeral pathologies that required an additional repair. The remaining 156 patients (41.5%) received a debridement of their concomitant pathologies. Rockwood grade V compared to Rockwood grade III (p = 0.013; odds ratio 1.7), and chronic compared to acute injury were significantly associated with having a concomitant glenohumeral pathology (p = 0.019; odds ratio 1.7). The probability of having a concomitant glenohumeral pathology was also significantly associated with increasing age (p < 0.0001).

CONCLUSIONS

Concomitant glenohumeral pathologies were observed in 53% of surgically treated patients with an acute or chronic acromioclavicular joint injury of either grade III or V. Twenty-two percent of these patients with concomitant glenohumeral pathologies received an additional dedicated repair procedure. Although a significant difference in occurrence of concomitant glenohumeral pathologies was seen between Rockwood grades III and V, and between acute and chronic lesions, increasing age was identified as the most dominant predictor.

LEVEL OF EVIDENCE

Level IV, case series.

Arthroscopic Acromioclavicular Joint Reconstruction Using Knotless Coracoclavicular Fixation and Soft-Tissue Anatomic Coracoclavicular Ligament Reconstruction

Acromioclavicular joint injuries are one of the most common shoulder injuries, and there are a variety of treatment options. Recently, there have been newer arthroscopic techniques that have addressed coracoid and clavicle fracture risk by using a knotted suture-button fixation through a single, small bone tunnel with additional looped soft-tissue graft stabilization. Although clinical outcomes have been good to excellent, there have still been instances of knot and hardware irritation. The described technique builds on the latest advances and achieves an anatomic coracoclavicular (CC) reconstruction through a single knotless CC fixation device with additional soft-tissue allograft reconstruction of the CC ligaments. This technique minimizes the risks of coracoid and clavicle fractures and knot and hardware irritation while maintaining excellent stability.

Arthroscopic fixation of the clavicle shaft fracture

This article describes an arthroscopic technique for the fixation of clavicle shaft fractures. A viewing portal is made 2 cm anterior to the fracture site, and a working portal is made 2 cm lateral to the fracture site. The guide wire for a 4.0-mm cannulated screw is inserted through the fracture site to the medial fracture fragment under arthroscopic guidance. Through the medial fragment, the guide wire is delivered through the skin anteriorly. The fracture is reduced, and then, the guide wire is drilled back across the fracture site to the lateral fracture fragment. After confirming the reduction under arthroscopy, the appropriately sized cannulated screw is inserted after reaming. This arthroscopic technique would be useful for the precise reduction and minimal invasive fixation of clavicle shaft fractures. Preliminary results are encouraging, and further studies with long-term follow-up are needed to determine the precise indications and limitations of the procedure.

[Injuries of the acromioclavicular joint: Hook plate versus arthroscopy]

Acute acromioclavicular (AC) joint injuries are common in clinical practice. The hook plate is a well-established conventional operative treatment option for high grade instability; however, arthroscopically-assisted flexible double button techniques are increasingly being used. Both procedures lead to good or excellent results. The advantages of the hook plate are the simple surgical technique and the possibility of an early functional aftercare. The minimally invasive one-step procedure with the possibility of identification and treatment of frequently concomitant glenohumeral pathologies is advantageous for the arthroscopic technique but mobilization is more restrictive. Available comparative studies have shown no significant clinical differences but a tendency towards better results with a higher degree of acceptance among patients for the arthroscopic and minimally invasive non-rigid double button procedures.

Shoulder acromioclavicular joint reconstruction options and outcomes

Acromioclavicular joint separations are a common cause of shoulder pain in the young athletic population. In high-grade injuries, acromioclavicular joint reconstruction procedures may be indicated for functional improvement. There is currently no gold standard for the surgical management of these injuries. Multiple reconstructive options exist, including coracoclavicular screws, hook plates, endobutton coracoclavicular fixations, and anatomic ligament reconstructions with tendon grafts. This article aims to review pertinent acromioclavicular joint anatomy and biomechanics, radiographic evaluation, classification system, as well as reconstruction options, outcomes, and complications.

Arthroscopic Stabilization of Chronic Acromioclavicular Joint Dislocations: Triple- Versus Single-Bundle Reconstruction

BACKGROUND

Arthroscopically assisted single-bundle (SB) or double-bundle coracoclavicular (CC) ligament reconstruction using autologous tendon grafts has been reported to provide acromioclavicular (AC) joint (ACJ) stability in chronic instability cases. Recently, additional AC ligament reconstruction to provide triple-bundle (TB) stabilization has been introduced but lacks a comparison of clinical and radiological outcomes.

HYPOTHESIS

Arthroscopically assisted anatomic TB CC and AC reconstruction yields superior clinical and radiological results when compared with nonanatomic SB CC reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Twenty-six patients (mean [±SD] age, 46.9 ± 12.8 years) suffering from chronic high-grade ACJ instability underwent ACJ stabilization using autologous hamstring grafts. Twelve patients underwent combined anatomic TB CC and AC reconstruction using a semitendinosus tendon with clavicular interference screw fixation (TB group), and 14 underwent isolated SB CC reconstruction using the AC GraftRope system with a gracilis tendon (SB group). After a minimum follow-up of 2 years (mean, 29.0 ± 7.4 months), patients were evaluated radiologically and clinically using the Constant, American Shoulder and Elbow Surgeons (ASES), Taft, and Acromioclavicular Joint Instability Score (ACJI) outcome measures.

RESULTS

The mean Constant score increased significantly in both groups, from 71.6 preoperatively to 88.8 postoperatively in the TB group and from 67.8 to 82.6 in the SB group (P ≤ .009). No intergroup difference was found regarding the final Constant or ASES scores. Regarding the ACJ-specific scores, the final outcomes were significantly different: 10.9 (TB group) versus 9.0 (SB group) for the mean Taft score (P = .018) and 84.7 versus 58.4, respectively, for the mean ACJI score (P = .0001). No significant radiological difference was found regarding the mean CC distance (10.7 mm [TB group] vs 13.1 mm [SB group]). The TB group showed superior horizontal ACJ stability (P = .011), which was associated with a better clinical outcome according to the ACJI and Taft scores. In the SB group, the rate of ACJ instability recurrence was higher (21% vs 8% [TB group]).

CONCLUSION

Combined arthroscopically assisted anatomic TB CC and AC ligament reconstruction using an autologous semitendinosus tendon graft provides superior clinical and radiological results compared with isolated nonanatomic SB CC ligament reconstruction using the AC GraftRope system. In particular, the TB technique can better restore horizontal ACJ stability, which is associated with superior ACJ-specific outcome scores.

Two-Year Outcomes After Primary Anatomic Coracoclavicular Ligament Reconstruction

PURPOSE

The purpose of this study was to report the clinical and structural outcomes after anatomic coracoclavicular ligament reconstruction (ACCR) with free tendon allografts in patients with grade III and grade V acromioclavicular (AC) joint dislocations.

METHODS

Thirty-one shoulders underwent primary ACCR with tendon allografts for Rockwood grade III and grade V AC joint dislocations. Preoperative data included patient demographic characteristics, injury characteristics, and surgical history, along with American Shoulder and Elbow Surgeons (ASES) scores, Short Form 12 Physical Component Summary (SF-12 PCS) scores, and various pain scales. Outcome measures were also collected a minimum of 2 years postoperatively with the addition of Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores; Single Assessment Numeric Evaluation (SANE) scores; and patient satisfaction. In addition, preoperative and postoperative coracoclavicular distances were analyzed using standard anteroposterior radiographs.

RESULTS

ACCR was performed in 31 patients (31 shoulders) with a mean age of 43.9 years (range, 21 to 71 years). In 7 patients (22.6%) a complication occurred that required a subsequent surgical procedure including graft rupture/attenuation (2), clavicle fractures (2), distal clavicle hypertrophy (2), and adhesive capsulitis (1). Of the remaining 24 patients, 20 (83.3%) had subjective outcome data available after a minimum 2-year follow-up period (mean, 3.5 years; range, 2.0 to 6.2 years). The mean postoperative ASES and SF-12 PCS scores significantly improved when compared with the preoperative baseline values (58.9 v 93.8 for ASES scores [P < .001] and 45.3 v 54.4 for SF-12 PCS scores [P = .007]). At final follow-up, the SANE and QuickDASH scores were 89.1 and 5.6, respectively, with a median patient satisfaction rating of 9 of 10.

CONCLUSIONS

Patients who did not require revision surgery showed excellent postoperative outcome scores: The mean ASES score was 93.8, the mean SANE score was 89.1, and the mean QuickDASH score was 5.6, with a median patient satisfaction rating of 9 of 10. Further study regarding ACCR techniques should focus on decreasing the risks of complications and maintaining reduction of the AC joint.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

All-Arthroscopic Technique for Reconstruction of Acute Acromioclavicular Joint Dislocations

Acromioclavicular joint dislocations are a common injury particularly among contact sports players. There has been an increasing trend toward arthroscopic management of these injuries. To date, these reconstructions have primarily addressed superoinferior instability by reconstructing the coracoclavicular ligaments. We describe an all-arthroscopic technique for reconstruction of the coracoclavicular ligaments using Arthrex ABS TightRopes (Arthrex, Naples, FL), with additional stabilization of the superior acromioclavicular joint capsule using an anchor-based suture bridge to address anteroposterior instability.

Anatomical Double-Bundle Coracoclavicular Reconstruction in Chronic Acromioclavicular Dislocation

The purpose of this study was to evaluate the clinical and radiological outcomes of anatomical double-bundle coracoclavicular (CC) reconstruction using the coracoacromial (CA) ligament and the conjoined tendon for the treatment of chronic acromioclavicular (AC) joint dislocation. A retrospective evaluation was performed on 18 patients who underwent an anatomical CC reconstruction using the CA ligament and the conjoined tendon for chronic AC joint dislocation. Patients were treated surgically between April 2007 and January 2012. Mean follow-up was 35.3 months (range, 24-49 months). All patients were evaluated for functional outcomes using the modified University of California, Los Angeles (UCLA) shoulder rating scale for chronic AC injury and the Constant-Murley shoulder outcome score. Range of motion and shoulder and elbow strength were also measured. Plain radiographs were taken to evaluate reduction status and CC distance. Mean modified UCLA shoulder rating scale at final follow-up was 18.1 points (range, 13-20 points). No significant difference in mean Constant-Murley scores existed between the injured and contralateral shoulders (P=.26). At final follow-up, 15 (83.3%) patients had well-maintained reduction and 2 (11.1%) patients had a partial loss of reduction. One other patient had a complete loss of reduction due to a postoperative fall. The CC distance was not significantly different between the injured and contralateral shoulders in the immediate postoperative period (P=.46) or at final follow-up (P=.14). One superficial wound infection occurred and was treated with routine wound care. An anatomical double-bundle CC reconstruction using the CA ligament and the conjoined tendon for the treatment of chronic AC joint dislocation is a reliable surgical method with good results.

Management of acromioclavicular joint injuries

Although recent advances have been made in the treatment of acromioclavicular (AC) joint injuries, they are still challenging for shoulder surgeons. There is a consensus that type I and II injuries should be treated nonoperatively, whereas acute type IV, V, and VI injuries should be treated surgically. There is no algorithm for correctly diagnosing and treating type III injuries, but the current trend is toward nonoperative treatment except for those with persistent symptoms and functional limitations after a course of conservative management. If surgery is indicated, newer anatomic techniques of reconstructing the coracoclavicular (CC) and AC ligaments are recommended.

Biomechanical Consequences of Coracoclavicular Reconstruction Techniques on Clavicle Strength

BACKGROUND

Lateral clavicle fractures have been reported after coracoclavicular (CC) ligament reconstructions with bone tunnels through the clavicle.

PURPOSE

To biomechanically compare clavicle strength following 2 common CC reconstruction techniques with different bone tunnel diameters.

STUDY DESIGN

Controlled laboratory study.

METHODS

Testing was performed on 2 groups of matched-pair cadaveric clavicles. Clavicles were prepared with either 2.4-mm tunnels and cortical fixation button (CFB) devices or 6.0-mm tunnels with hamstring tendon grafts (TGs) and tenodesis screws; contralateral clavicles were left intact. A 3-point bending load was applied to the distal clavicles at a rate of 15 mm/min until failure. Ultimate failure load and anterior-posterior width of the clavicles 45 mm medial from the lateral border were recorded. Strength reduction was determined as the percentage reduction in ultimate failure load between paired intact and surgically prepared clavicles. Relative tunnel size was determined as the quotient of tunnel diameter and clavicle width, reported as a percentage.

RESULTS

The TG technique significantly reduced clavicle strength relative to intact (P = .011) and caused significantly more strength reduction (mean, -30.7%; range, 8.1% to -62.5%) than the CFB technique (mean, -3.8%; range, 34.2% to -28.1%; P = .031). The CFB technique was not significantly different from intact (P = .314). There was a significant correlation between clavicle width and strength reduction (τ = -0.36, P = .04) and between relative tunnel size and strength reduction (τ = 0.51, P = .005).

CONCLUSION

The TG reconstruction technique with 6.0-mm tunnels, grafts, and tenodesis screws caused significantly more reduction of clavicle strength compared with the CFB technique with 2.4-mm tunnels and CFB device. Additionally, relative tunnel width correlated highly with the strength reduction.

CLINICAL RELEVANCE

This information can influence intraoperative decision making based on the individual clavicle width and might influence postoperative treatment protocols. Large bone tunnels may predispose patients to clavicle fractures after anatomic CC reconstructions.