Vertical and Rotational Stiffness of Coracoclavicular Ligament Reconstruction: A Biomechanical Study of 3 Different Techniques.

PURPOSE: To compare the biomechanical stability of 3 different coracoclavicular reconstruction techniques under rotational and vertical loading using a cadaveric model. METHODS: In total, 12 cadaveric shoulders were used for testing. The native state was first tested then followed by 3 different reconstruction configurations using suture tapes and cortical buttons: coracoid loop (CL), single-bundle (SB), and double-bundle (DB). Superior displacement was measured by cycling an inferiorly directed force of 70 N to the scapula. The rotational stiffness of the scapula was determined by cycling the scapula in rotational displacement control between 15° of internal and external rotation. The rotational stiffness of the clavicle was determined by rotating the clavicle around its long axis 20° anteriorly and 30° posteriorly in rotational displacement control. All measurements were captured over 10 cycles at a rate of 200 Hz. RESULTS: Both the CL and SB techniques demonstrated significantly less internal scapular rotation stiffness. (intact: 19.70 ± 9.07 cNm/deg, CL: 3.70 ± 2.63 cNm/deg, SB:4.30 ± 2.66 cNm/deg, P <.001) External scapular rotation stiffness was significantly decreased in all techniques (intact: 17.70 ± 4.43 cNm/deg, CL: 3.30 ± 1.37 cNm/deg, SB: 4.50 ± 1.56 cNm/deg, DB: 4.67 ± 1.99 cNm/deg, P < .001). The CL and SB reconstructions were significantly less stiff with regards to posterior rotation of the clavicle (intact: 5.60 ± 1.80 cNm/deg, CL: 2.90 ± 1.10 cNm/deg, SB: 1.40 ± 0.65 cNm/deg, P < .001). Anterior rotation stiffness of the clavicle was significantly lower in all of the reconstructions (intact: 6.95 ± 1.90 cNm/deg, CL: 3.08 ± 0.84 cNm/deg, SB: 3.64 ± 0.93 cNm/deg, DB: 4.48 ± 1.21 cNm/deg, P < .001). CONCLUSIONS: None of the described techniques provided equivalent rotational stability in all planes compared with the native state. DB reconstruction presented stiffness characteristics closest to the native state under cyclic loading during internal scapular and posterior clavicular rotation. CLINICAL RELEVANCE: Additional procedures such as tendon grafting or acromioclavicular ligament reconstruction may be required to control rotational stability.

Reconstruction of the Acromioclavicular Ligament Complex Using Dermal Allograft: A Biomechanical Analysis.

PURPOSE: To analyze the posterior translational and rotational stability of the acromioclavicular (AC) joint following reconstruction of the superior acromioclavicular ligament complex (ACLC) using dermal allograft. METHODS: Six fresh-frozen cadaveric shoulders were used (mean age of 65.3 ± 6.9 years). The resistance force against posterior translation (10 mm) and torque against posterior rotation (20°) was measured. Specimens were first tested with both the intact ACLC and coracoclavicular ligaments. The ACLC and coracoclavicular ligaments were then transected so simulate a Type III/V AC joint dislocation. Each specimen then underwent 3 testing conditions, performed in the following order: (1) ACLC patch reconstruction alone, (2) ACLC patch with an anatomic coracoclavicular reconstruction (ACCR) using semitendinosus allograft, and (3) the transected ACLC with an ACCR only. Differences in posterior translational and rotational torque across testing conditions were analyzed with a one-way repeated analysis of variance analysis. RESULTS: Mean resistance against posterior translation in the intact condition was 65.76 ± 23.8 N. No significant difference found between the intact condition compared with specimens with the ACLC-patch only (44.2 ± 11.3 N, P = .06). The ACCR technique, when tested alone, had significantly less posterior translational resistance compared with the intact condition (38.5 ± 8.94 N, P = .008). ACLC patch in combination with an ACCR was closest in restoring native posterior translation (57.1 ± 19.2 N, P = .75). For rotational resistance, only the addition of the ACLC patch with an ACCR (0.51 ± 0.07 N-m) demonstrated similar torque compared with the intact joint (0.89 ± 0.5 N-m, P = .06). CONCLUSIONS: The ACLC-patch plus ACCR technique was able to closest restore the percent of normal posterior translational and rotational stability. CLINICAL RELEVANCE: Recurrent posterior instability of the AC joint is a potential complication after coracoclavicular reconstruction surgery. In the in vitro setting, this study demonstrated increased AC joint stability with the addition of an ACLC reconstruction using dermal allograft.

The long-term efficacy of the GraftRope technique.

BACKGROUND: Acromioclavicular joint separations continue to be a challenge for surgeons, and modern arthroscopically assisted techniques are becoming increasingly widespread. The aim of this study is to evaluate if the use of a biological support in association with a nonresorbable subcoracoid fixation can improve long-term stability in acromioclavicular joint dislocation surgically treated. We assessed clinical and radiographic results, patients' return to daily activities and the risk of complications. MATERIALS AND METHODS: Fourteen patients underwent subcoracoid fixation with the GraftRope system for chronic Rockwood type IV acromioclavicular joint dislocation. A total of 12 patients were evaluated clinically and radiologically with a minimum of 7 years of follow-up. RESULTS: Good reduction was obtained in all patients. All patients returned to work and sports at the pretrauma level with high mean scores on clinical evaluation. Regarding complications, 3 patients developed acromioclavicular arthritis. Ossifications were a common finding on x-rays, but they did not worsen the clinical outcome. CONCLUSIONS: The GraftRope surgical technique allows us to obtain an anatomical reduction of the acromio-clavicular joint, along with the restoration of the mechanical properties of the joint, owing to the use of a biological material with rigidity and load resistance features. Clinical results over the long term are encouraging. However, a 6-mm bone tunnel is too large since the average thickness of the coracoid process is only approximately 12 mm. This technique has some advantages over others: it avoids detachment of the deltoid, avoids the use of bulky metal implants with an important dissection of soft tissue, while it has all the advantages of an arthroscopic procedure.

Can an acute high-grade acromioclavicular joint separation be reduced and stabilized without surgery? A surgeon's experience.

INTRODUCTION: While the management of Rockwood type III injuries is still a topic of debate, high-grade Rockwood type V injuries are mostly treated surgically, to anatomically reduce the acromioclavicular (AC) joint and to restore functionality. In this case report, we present a method for non-operative reduction and stabilization of a high-grade AC joint injury. CASE: A 31-year-old male orthopaedic resident sustained a Rockwood type V injury during a snowboarding accident. His AC joint was reduced and stabilized with an AC joint brace for six weeks. The brace provided active clavicle depression and humeral elevation. After removal of the brace the AC joint showed a nearly anatomic reduction. Six-month follow-up weighted X-ray views showed an AC joint which had healed in a Rockwood type II position and the patient returned to full pre-injury function with a satisfying cosmetic appearance. CONCLUSION: Non-operative reduction and stabilization of high-grade AC joint separations seems to be a valuable treatment option. A "closed reduction and external fixation" approach with the aid of a dedicated AC joint brace can reduce the AC joint and keep it in place until ligamentous consolidation occurs, thus improving AC joint stability and cosmetic appearance without surgical intervention.

Ultrasound-Guided Prolotherapy for Acromial Enthesopathy and Acromioclavicular Joint Arthropathy: A Single-Arm Prospective Study.

OBJECTIVES: Prolotherapy is an injection-based complementary treatment for various musculoskeletal diseases. The aim of this study was to evaluate the therapeutic efficacy of ultrasound-guided prolotherapy in the treatment of acromial enthesopathy and acromioclavicular joint arthropathy. METHODS: Thirty-one patients with chronic moderate-to-severe shoulder pain were recruited from September 2015 to September 2017. Ultrasound-guided prolotherapy was performed by injecting 10 mL of a 15% dextrose solution into the acromial enthesis of the deltoid or acromioclavicular joint capsule aseptically. Prolotherapy was given in 2 sessions separated by a 1-month interval. The pretreatment-to-posttreatment change in the pain visual analog scale (VAS) score was recorded as the primary outcome. The mean follow-up duration was 61.8 days. A paired t test was used to assess the difference in pretreatment and posttreatment VAS scores. A univariate logistic regression analysis was conducted to identify the demographic variables associated with substantial pain reduction after the intervention. Substantial pain reduction was defined as a posttreatment VAS score of 3 or less. RESULTS: Twenty of the 31 patients reported substantial pain reduction without adverse effects after the intervention. The mean VAS score reduction ± SD was 4.3 ± 2.6 (pretreatment, 6.8 ± 1.5; posttreatment, 2.5 ± 2.1; P < .01). CONCLUSIONS: Ultrasound-guided prolotherapy with a 15% dextrose solution is an effective and safe therapeutic option for moderate-to-severe acromial enthesopathy and acromioclavicular joint arthropathy.

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.

A biomechanical comparison of new techniques for distal clavicular fracture repair versus locked plating.

BACKGROUND: Unstable distal clavicular fractures treated surgically are associated with high failure rates and hardware-related complications. Newer techniques have shown promising early clinical results with fewer hardware complications; however, their biomechanical performance has not been assessed. This study biomechanically compared a distal-third locking plate with 3 newer techniques that incorporate coracoid fixation into the construct. METHODS: The study randomized 36 adult fresh frozen cadaveric shoulders to 4 groups: (1) distal-third locking plate (P); (2) distal-third locking plate with a coracoid button augmentation (P + CB); (3) coracoclavicular button (CB); and (4) coracoclavicular button with coracoclavicular ligament reconstruction using semitendinosus allograft (CB + CC). After fixation, each specimen was stressed in the coronal plane. Cyclic displacement, load at 10-mm displacement, and ultimate load to failure were measured. RESULTS: All 3 experimental groups biomechanically outperformed the locking plate. Mean load to failure was significantly higher in the CB (343 ± 76 N) and CB + CC (349 ± 94 N) groups compared with the P group (193 ± 52 N). There was also significantly less cyclic displacement in the CB (4.3 ± 1.9 mm) and CB + CC (4.4 ± 1.9 mm) groups compared with the P group (8.2 ± 2.9 mm). With respect to load at 10 mm of displacement, which essentially measures a clinical failure, the P + CB (235 ± 112 N), CB (253 ± 111 N), and CB+CC (238 ± 76 N) experimental groups significantly outperformed the P group (96 ± 29 N). CONCLUSIONS: CB and CB + CC techniques demonstrated more than 75% greater strength than the traditional locking plate alone. Coupled with greater overall construct strength and lower-profile hardware, these newer techniques may result in improved clinical outcome and fewer hardware-related complications.

Clinical effectiveness of surgical treatment with polyester tapes and temporary K-wires on complete acromioclavicular dislocation.

INTRODUCTION: Ideal treatment of acute acromioclavicular joint (ACJ) dislocation remains unresolved. We evaluated ACJ reconstruction using polyester tapes and temporary Kirschner wire (KW) and presented clinical and radiological outcomes. MATERIALS AND METHODS: Patients were retrospectively evaluated and classified according to Rockwood classification, clinical and sportive characteristics. Constant Score (CS) and ACJ joint instability (ACJI) score were collected. Zanca's, Alexander, axillary, standard, and stress AP views were collected. Radiographic coracoclavicular distance (CCd) of healthy and injured shoulders was measured pre-operatively, at 3 months and at minimum 2-year follow-up. Heterotopic ossifications and clavicular osteolysis were evaluated. Influence of patients' characteristics and AC joint type on clinical and radiological outcomes were determined. RESULTS: Sixteen patients (13 type V and 3 type III ACJ dislocation) reached the end of follow-up (mean 2.4 years; range 22-72 months). Mean CS was 99.63 (range 96-100), while the mean ACJI score was 96.19 (range 85-100). The CCd of the treated shoulder was comparable with the healthy shoulder at 3 months and at last follow-up; moreover, there was no difference in CCd scores at 3 months and at 2 years. CCd scores were lower in sedentary patients compared with physically active (sporty) patients. Heterotopic ossifications were observed in three patients. No osteolysis was reported. CONCLUSION: This technique provides good results with few complications and should be considered as an effective method to treat ACJ acute dislocation. CCd scores correlate with overuse factors but not with other clinical scores.

Does Distal Clavicle Resection Decrease Pain or Improve Shoulder Function in Patients With Acromioclavicular Joint Arthritis and Rotator Cuff Tears? A Meta-analysis.

BACKGROUND: Acromioclavicular joint arthritis is a common, painful, and often missed diagnosis, and it often accompanies other shoulder conditions such as rotator cuff disease. Whether distal clavicle resection is important to perform in patients undergoing surgery for rotator cuff tears and concomitant acromioclavicular joint arthritis is controversial. QUESTIONS/PURPOSES: The purpose of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of distal clavicle resection on (1) outcome scores; (2) shoulder ROM, joint pain or tenderness, and joint instability; and (3) risk of reoperation among patients treated surgically for rotator cuff tears who had concomitant acromioclavicular joint arthritis. METHODS: We systematically searched the PubMed, EMBASE, and Cochrane databases to find RCTs that met our eligibility criteria, which, in summary, (1) compared rotator cuff repair plus distal clavicle resection with isolated rotator cuff repair for patients who sustained a full- or partial-thickness rotator cuff tear and concomitant acromioclavicular joint arthritis; and (2) the followup period was at least 2 years. Two reviewers screened the studies, extracted the data and evaluated the methodological quality, and performed data analysis. Statistical heterogeneity among studies was quantitatively evaluated with the I index. No heterogeneity was detected (I = 0%; p = 0.75) in terms of acromioclavicular joint pain or tenderness, Constant score, forward flexion, external rotation, and risk of reoperation, so fixed-effect models were used in these endpoints. Heterogeneity was moderate for the American Shoulder and Elbow Surgeons (ASES) score (I = 53%; p = 0.12) and low for the visual analog scale (VAS) score (I = 35%; p = 0.22), so random-effect models were used in these endpoints. Subgroup analysis was stratified by the symptom of acromioclavicular joint arthritis. Three RCTs with 208 patients were included. We evaluated the risk of bias using the Cochrane risk-of-bias tool; in aggregate, the three RCTs included showed low to intermediate risk, although not all parameters of the Cochrane tool could be assessed for all studies. RESULTS: There was no difference between the distal clavicle resection plus rotator cuff repair group and the isolated rotator cuff repair group in ASES score (mean difference =1.41; 95% confidence interval [CI], -3.37 to 6.18; p = 0.56) nor in terms of the VAS score and Constant score. Likewise, we found no difference in ROM of the shoulder (forward flexion, internal rotation, and external rotation) or acromioclavicular joint pain or tenderness between the groups (pooled results of acromioclavicular joint pain or tenderness: risk ratio [RR], 1.59; 95% CI, 0.67-3.78; p = 0.30). Acromioclavicular joint instability was only detected in the rotator cuff repair plus distal clavicle resection group. Finally, we found no difference in the proportion of patients undergoing repeat surgery between the study groups (pooled results of risk of reoperation for the rotator cuff repair plus distal clavicle resection and isolated rotator cuff repair: one of 52 versus two of 78; RR, 0.86; 95% CI, 0.11-6.48; p = 0.88). CONCLUSIONS: Distal clavicle resection in patients with rotator cuff tears did not result in better clinical outcome scores or shoulder ROM and was not associated with a lower risk of reoperation. Distal clavicle resection might cause acromioclavicular joint instability in patients with rotator cuff tears and concomitant asymptomatic acromioclavicular joint arthritis. Arthroscopic distal clavicle resection is not recommended in patients with rotator cuff tears and concomitant acromioclavicular joint arthritis. Additional well-designed RCTs with more participants, long-term followup, and data on patient-reported outcomes are needed. LEVEL OF EVIDENCE: Level I, therapeutic study.

Biomechanical Analysis of Single-, Double-, and Triple-Bundle Configurations for Coracoclavicular Ligament Reconstruction Using Cortical Fixation Buttons With Suture Tapes: A Cadaveric Study.

PURPOSE: To compare the acromioclavicular (AC) joint stability of single-bundle (SB), double-bundle with an anterolateral limb (DBa), double-bundle with a posterolateral limb (DBp), and triple-bundle (TB) coracoclavicular (CC) ligament reconstructions using cortical fixation buttons with suture tapes. METHODS: Eight cadaveric shoulders were used. AC joint translation and rotational stability were tested for intact and following 4 different CC reconstruction techniques: SB, DBa, DBp, and TB configurations using cortical fixation buttons with suture tapes. For each reconstruction and native AC joint as control, anteroposterior (AP) and superoinferior translations were quantified using 10- and 15-N translational loads and anterior and posterior rotations were measured using 0.16- and 0.32-Nm rotational torque. RESULTS: DBp reconstruction showed significantly better AP stability compared with SB and DBa reconstruction at 10 and 15 N (DBp: 4.1 ± 0.6 mm, SB: 7.8 ± 1.1 mm, P < .001; DBa: 6.5 ± 0.7 mm, P = .02 at 10 N; DBp: 5.5 ± 0.8 mm, SB: 10.1 ± 1.0 mm, P = .003; DBa: 9.1 ± 0.7 mm, P = .02 at 15 N). The degree of total rotation showed tendency to decrease according to increasing number of bundles; however, there were no significant differences (SB: 43.1 ± 9.2°, DBa: 37.9 ± 7.3°, DBp: 33.9 ± 6.8°, TB: 32.2 ± 6.6°, P = .37 at 0.32 Nm). CONCLUSIONS: An additional posterolateral clavicular hole for CC ligament reconstruction using cortical fixation buttons with suture tapes resulted in better AP stability compared with SB reconstruction, whereas use of additional anterolateral clavicular hole did not show any improvement compared with SB reconstruction. Reconstruction using both anterolateral and posterolateral clavicular holes did not guarantee better stability compared with SB reconstruction. There was an increasing tendency of rotational stability with number of bundle increases, although they did not reach statistical difference. CLINICAL RELEVANCE: When surgeons consider double-bundle CC ligament reconstruction using cortical fixation buttons with suture tapes, it is better to position the lateral clavicular hole posteriorly to restore AP stability.

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

BACKGROUND: Acromioclavicular (AC) joint (ACJ) pathology is a common cause of shoulder dysfunction, and treatment recommendations vary. When the efficacy of treatment is evaluated, the ability to measure outcomes specific to the population is essential. The aim of the current research was to develop and validate a specific ACJ questionnaire. METHODS: Items for the "Specific AC Score" (SACS) were generated through the use of an expert panel, existing questionnaires, and patient feedback. Preliminary data analysis identified redundancy of items resulting in the questionnaire being refined. The final SACS was evaluated in 125 patients requiring surgical intervention of the ACJ. Internal consistency (the Cronbach α and corrected item-total correlation), content validity, criterion validity, responsiveness, and test-retest reliability (intraclass correlation coefficient) were examined and compared with the Shoulder Pain and Disability Index, Oxford Shoulder Score, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form. The minimum detectable change score was calculated. RESULTS: The Cronbach α for the total scale preoperatively and postoperatively was high (preoperatively = 0.91, postoperatively = 0.93). All 3 domains (Pain, Function, Quality of Life) demonstrated acceptable internal consistency (α > 0.70), and the correlation between items in each domain was satisfactory. The responsiveness was excellent (effect size, -2.32; standard response mean, -1.85) and was higher than the other general shoulder questionnaires. There were no relevant floor or ceiling effects. Reliability was high (intraclass correlation coefficient, 0.89) and the minimum detectable change was 6.5 points. DISCUSSION: This new ACJ-specific questionnaire has been robustly developed, has good measurement properties, and has excellent responsiveness. The SACS is recommended for measuring outcomes in ACJ patients.

Truly anatomic coracoclavicular ligament reconstruction with 2 Endobutton devices for acute Rockwood type V acromioclavicular joint dislocations.

BACKGROUND: Truly anatomic coracoclavicular ligament reconstruction (TACCR) according to the original insertions is a creative new method for the treatment of severe acromioclavicular separation. This research analyzed the clinical and radiologic results of TACCR in 25 patients with at least 2-year follow-up. METHODS: The study enrolled 25 patients with Rockwood type V acromioclavicular joint dislocations who underwent TACCR using 2 Endobutton (Smith & Nephew Inc., Andover, MA, USA) devices from May 2013 to October 2015. Patients were assessed with clinical and radiologic follow-up at 3, 6, 12, 18, and 24 months postoperatively. The clinical assessments consisted of the visual analog scale and the Constant score. The radiographic evaluations were performed by measurements of the coracoclavicular distance. RESULTS: The mean follow-up was 34 ± 6.8 months (range, 24-48 months). The visual analog scale and Constant scores revealed significant advancements from 5 ± 0.9 (range, 4-7) and 45 ± 5.6 (range, 30-54) scores preoperatively to 0 ± 0.5 (range, 0-2) and 95 ± 2.9 (range, 91-98) scores at 24 months postoperatively, respectively. The coracoclavicular distance significantly decreased from 23 ± 5.4 mm (range, 16-34 mm) preoperatively to 8 ± 0.9 mm (range, 7-10 mm) at the final follow-up. CONCLUSIONS: TACCR represents a safe, reliable and creative surgical technique that yields good to excellent clinical and radiologic outcomes in the treatment of severe acromioclavicular separation.

A prospective study of coracoclavicular ligament reconstruction with autogenous peroneus longus tendon for acromioclavicular joint dislocations.

BACKGROUND: Anatomic coracoclavicular (CC) ligament reconstruction (ACCR) provides good outcomes for Rockwood type III and VI acromioclavicular (AC) joint dislocations. Various grafts have been used, but complications from graft harvesting are not uncommon. This study examined the clinical and radiographic outcomes of patients with AC joint dislocations repaired with the autogenous anterior half of the peroneus longus tendon (AHPLT) to achieve ACCR. METHODS: Patients with a Rockwood type III to V AC joint dislocation and magnetic resonance imaging of the disruption of the CC ligaments, as well as the AC capsule, were prospectively recruited. Patients received ACCR using an autogenous AHPLT graft and were evaluated clinically and radiographically preoperatively and at 1, 3, 6, and 12 months postoperatively. RESULTS: A total of 18 patients (mean age, 51 years) were prospectively recruited and received an autogenous AHPLT graft ACCR. Fifteen patients completed clinical and radiographic follow-up examinations at 12 months. The mean Constant score (CS) was 51 preoperatively and 93 at 12 months (P <.005). No significant difference was noted at 12 months between the CS of the injured and contralateral shoulder. The mean American Orthopedic Foot and Ankle Society score at 12 months was 99, and this was not different from the value at any other time point. Loss of reduction occurred in 10 patients (56%), and tunnel widening was observed in 9 (50%), but neither was significantly correlated with functional outcome. CONCLUSION: Autogenous AHPLT appears to be a reliable tendon graft source for CC ligament reconstruction.

Clinical outcomes of a single-tunnel technique for coracoclavicular and acromioclavicular ligament reconstruction.

BACKGROUND: A large number of surgical techniques have been described to treat acromioclavicular (AC) joint separations. Despite the high success rates with double-tunnel reconstruction, this method has been associated with the risk of coracoid and clavicle fractures. This study aimed to evaluate the outcomes of the first cohort of patients who underwent single-tunnel AC and coracoclavicular (CC) ligament reconstruction. It was hypothesized that this technique would result in maintenance of reduction and a minimal risk of fracture of the coracoid and clavicle. METHODS: All patients who underwent single-tunnel AC joint reconstruction between 2012 and 2015 via the technique with 2-year follow-up were included. Objective outcomes recorded were maintenance of reduction as measured by the CC distance on radiographs, shoulder range of motion, strength, return to sports, and complications. Subjective outcomes included maintenance of reduction on visual inspection and various patient-reported outcomes. RESULTS: Seventeen patients were included with a mean age of 41 ± 12 years. Separation types included types III, IV, and V. The mean follow-up period was 29 ± 9 months (range, 16-45 months). The CC distance improved from 37.4 to 30.0 mm on plain radiographs (P = .006), the American Shoulder and Elbow Surgeons score improved from 67.0 to 90.1 (P = .094), and the Single Assessment Numeric Evaluation score improved from 30.5 to 91.1 (P = .025). Reduction on visual inspection was maintained in 16 patients (94.1%). Regarding sports participation, 14 patients (82.4%) returned to their preinjury level. The most common complication was a prominent suture knot stack, occurring in 3 patients (17.6%), which was removed in all 3 in a second procedure. There were no clavicle or coracoid fractures. CONCLUSION: The described technique results in satisfactory objective and patient-reported outcomes and return to sports while avoiding coracoid and clavicle fractures.

Treatment of Symptomatic Acromioclavicular Joint Instability by a Docking Technique: Clinical Indications, Surgical Technique, and Outcomes.

PURPOSE: To report functional and objective outcomes resulting from surgical treatment of patients with symptomatic type III through V acromioclavicular (AC) joint injury by use of a modification of the anatomic AC joint reconstruction developed by Carofino and Mazzocca. METHODS: The study included all patients treated in 2009-2014 who presented with a history of direct trauma to the shoulder; deformity of the AC joint on clinical examination; radiographic findings that would classify the injury as a Rockwood type III, IV, or V injury; AC joint instability on clinical examination; and self-reported deficits of arm function on initial presentation, in whom a comprehensive and directed nonoperative program failed. The surgical procedure used an allograft with reinforcing internal sutures passed around the coracoid and through anatomically positioned clavicular holes for the coracoclavicular (CC) ligaments, used a docking technique for reconstruction of the superior AC ligaments, and included repair of the native AC ligaments. Outcomes were reported for patients with a minimum follow-up period of 1.5 years. Outcome measurements included dynamic-static stability evaluation and Disabilities of the Arm, Shoulder and Hand (DASH) scores. RESULTS: The study included 15 patients with 15 affected shoulders. The postsurgical follow-up period averaged 3 years (range, 1.5-5 years). Postoperatively, one patient showed loss of reduction after a fall. All others showed 2-dimensional radiographic stability and 3-dimensional dynamic clinical stability. Static radiographic measurement of the CC distance at discharge averaged 0.93 cm compared with 2.7 cm on initial examination (P < .0001). Patient-reported outcomes at an average of 3 years' follow-up showed a DASH score of 13 compared with a preoperative DASH score of 51 (P < .0001). CONCLUSIONS: This study confirms that anatomic CC ligament reconstruction and repair or reconstruction of the AC ligaments help restore arm function as shown by the patient-specific and clinical outcome metrics. These results were achieved by correction of the deformity, which in turn allowed for the obtainment of static and dynamic stability. LEVEL OF EVIDENCE: Level IV.

The anterior borders of the clavicle and the acromion are not always aligned in the intact acromioclavicular joint: a cadaveric study.

BACKGROUND: The aim of this study was to find reliable anatomic landmarks of the normal acromioclavicular joint (ACJ) that could enable the precise evaluation of the horizontal displacement of the clavicle after dislocation. The hypothesis was that the anterior borders of the acromion and the clavicle are always aligned in intact ACJs. MATERIALS AND METHODS: In 30 cadaveric specimens, the anterior and posterior borders of the ACJ's articular facets and the most prominent anterior and posterior bony landmarks of the acromion and the clavicle were identified. The anterior and posterior overhang of the acromion and the clavicle was measured in relation to the borders of the articular facets. Therefore, the possible anterior and posterior alignment of the ACJ was evaluated. RESULTS: Anteriorly, only 18 ACJs (60%) were aligned whereas 7 (24%) had major overhang of the acromion and 3 (10%) had major overhang of the clavicle. Similarly, 18 cases (60%) were posteriorly aligned, whereas 6 (20%) had major clavicular overhang and 4 (14%) had major overhang of the acromion. In 78% of these cases, the ACJ was aligned as well anteriorly as posteriorly (P < .001). Finally, the larger the width of the acromion (P = .032) or the clavicle (P = .049), the better the posterior joint alignment. CONCLUSION: Our hypothesis was not verified. The acromion and clavicle are not perfectly aligned in a significant number of specimens with intact ACJs (40% of cases). The most reliable landmarks remain their articular facets.

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.

Palmaris longus tendon graft versus modified Weaver-Dunn procedure via dynamic button system for acromioclavicular joint reconstruction in chronic cases.

BACKGROUND: The hypothesis of this clinical study was that coracoclavicular (CC) reconstruction using autogenic palmaris longus graft through the GraftRope (PLG) system (Arthrex, Inc., Naples, FL, USA) would provide superior clinical and radiologic results compared with modified Weaver-Dunn procedure with the dynamic TightRope (Arthrex, Inc.) system (WDT). METHODS: Between 2008 and 2013, 32 patients (average age, 39.7 years; range, 22-60 years) underwent surgical reconstruction of chronic acromioclavicular (AC) joint dislocation. A modified WDT procedure was performed in 16 patients and autogenous PLG was performed in the other 16 patients. Patient data were collected retrospectively, with a final follow-up of 44.9 months (range, 29-60 months). The degree of AC joint displacement was evaluated by measuring the CC distance on the anteroposterior and axillary view. Clinical and functional outcomes were compared by American Shoulder and Elbow Surgeons and the Constant scores at final follow-up. RESULTS: Comparison between the WDT and PLG groups showed a significantly better outcome in the American Shoulder and Elbow Surgeons and the Constant scores (P < .01), in favor of the PLG group. Both groups showed an increased CC distance compared with the uninjured side, with a mean difference of 1.1 mm for the PLG and 3.3 mm for the WDT groups. A tolerable loss of reduction within the follow-up time was observed. Reduction loss was higher with the WDT group (P < .05). CONCLUSION: CC palmaris longus tendon graft reconstruction with GraftRope system was associated with functional and radiologic benefits. The palmaris longus graft with GraftRope system could be used in chronic cases.

Contact pressure of the coracoacromial arch in shoulders with joint contracture: A cadaveric study.

BACKGROUNDS: There have been many reports describing that the capsular fibrosis of the shoulder joint is the main cause of frozen shoulder, whereas others reported the significance of subacromial impingement as an etiological factor. The purpose of this study was to investigate the contact pressure between the coracoacromial arch and the rotator cuff tendons to clarify the contact phenomenon in shoulders with joint contracture. METHODS: Fourteen fresh-frozen cadaveric shoulders were used. Specimens were divided into two groups: normal group (8 shoulders, definition: more than 61° of flexion and abduction and more than 21° of external rotation) and joint contracture group (6 shoulders, definition: less than 60° of flexion and abduction and less than 20° of external rotation). Contact pressure and area beneath the coracoacromial arch were measured by a flexible force sensor during flexion, abduction, internal and external rotation in adduction and abduction, extension and horizontal extension motions. RESULTS: The peak contact pressure under the acromion was observed at 90° in flexion and abduction in the normal group, whereas that in the contracture group was observed at 30° in flexion (P = 0.037) and at 30° in abduction (P = 0.041). Contact pressure in the contracture group was significantly higher than that in the normal group at 20° and 30° of abduction (P = 0.043, P = 0.041, respectively). There were no significant differences of contact pressure during other motions. Although no significant differences of contact pressure beneath the coracoacromial ligament were observed, contact area significantly increased in extension and horizontal extension motion. CONCLUSION: The contact between the acromion and the rotator cuff was observed in lower angles of flexion and abduction in shoulders with contracture than in those without. When treating patients with shoulder contracture, we need to perform rehabilitation taking such an abnormal movement into consideration.

Biomechanical analysis of clavicle hook plate implantation with different hook angles in the acromioclavicular joint.

PURPOSE: A clavicle hook plate is a simple and effective method for treating acromioclavicular dislocation and distal clavicle fractures. However, subacromial osteolysis and peri-implant fractures are complicated for surgeons to manage. This study uses finite element analysis (FEA) to investigate the post-implantation biomechanics of clavicle hook plates with different hook angles. METHODS: This FEA study constructed a model with a clavicle, acromion, clavicle hook plate, and screws to simulate the implantation of clavicle hook plates at different hook angles (90°, 95°, 100°, 105°, and 110°) for treating acromioclavicular joint dislocations. This study investigated the biomechanics of the acromion, clavicle, hook plate, and screws. RESULTS: A smaller hook angle increases the stress on the middle third of the clavicle. A larger hook angle increases the force exerted by the clavicle hook plate on the acromion. The screw at the most medial position on the plate generated the highest stress. The highest stress on the implanted clavicle hook plate was on the turning corner of the hook. CONCLUSIONS: A clavicle hook plate with different hook angles may induce different biomechanical behaviors in the clavicle and acromion. Orthopedic surgeons must select a suitable clavicle hook plate based on the anatomical structure of each patient.