A review of the coracoclavicular joint: Description, etiology, and clinical significance.

The coracoclavicular joint (CCJ) is a synovial joint that forms between the conoid tubercle of the clavicle and the coracoid process of the scapula in approximately 2.5% of the population. The number of bilateral to unilateral cases is almost equal. The number of right-sided and left-sided cases is also almost equal. It is found in both males and females but most often in male adults. Very few cases have been identified in juveniles. Found in populations all over the world, the highest frequencies of CCJ are in Asia. The etiology is unknown but it is most likely caused by metaplastic change of the trapezoid and surrounding tissue due to compression and friction of the coracoacromial ligament between the clavicle and coracoid process. Typically asymptomatic, but if so, the most common complaint is anterior should pain exacerbated by extreme abduction. Successful treatment includes steroid injection and surgical excision.

Open coraco-clavicular ligament reconstruction (CCLR) in treatment of displaced distal clavicle fractures has low complication rate and excellent union rate: a systematic review.

BACKGROUND: It is well established that non-operative treatment of displaced distal clavicle fractures (DDCF) leads to a high non-union rate. A number of open surgical treatments in the past have shown good to excellent outcomes including shoulder function and union rate. Despite this there is no consensus on the outcome of open coraco-clavicular ligament reconstruction (CCLR). The aim of this systematic review was to assess the union rate, complications and shoulder function of open CCLR techniques in the treatment of DDCF. PATIENTS AND METHODS: A review of the online databases MEDLINE and Embase was conducted on 1 January 2021 according to PRISMA guidelines. The review was registered prospectively in the PROSPERO database. Clinical studies reporting union rate, complications and shoulder function were included. The studies were appraised using the Methodological Index for Non-Randomized Studies (MINORS) tool. RESULTS: The search strategy identified 18 studies eligible for inclusion with a total of 330 patients. These included 12 retrospective case series and 5 nonrandomized retrospective comparative studies and one RCT. All but one study reported on shoulder function, while all the studies reported on union rate and complications. The overall shoulder function was good to excellent using Constant-Murley score. The overall union rate was 97.6% and complication rate was 7.6%. CONCLUSION: Open CCLR for displaced distal clavicle fractures that have a disruption of CC ligament, is a reliable treatment with excellent union rate and good to excellent shoulder functional scores. LEVEL OF EVIDENCE: IV; Systematic review.

Operative management of lateral third clavicle fractures: a comparison of internal fixation methods.

PURPOSE: Clavicle fractures in the lateral third are associated with more complications. Various methods of internal fixation exist; however, there is no consensus which should be employed. The purpose of this study was to evaluate the outcomes of these various methods in our regional trauma unit. METHODS: We performed a retrospective review of patients who underwent internal fixation of a lateral clavicle fracture in our unit between 1 August 2014 and 31 July 2019. Demographic and outcome data were extracted from electronic care records and imaging systems. RESULTS: In total, 44 patients were included, with the following demographics: mean age 26 years, 63.6% male, 65.9% high-energy injury, 68.2% Neer II fracture. The following operations were performed: hook plate fixation (HPF) = 10, locking plate fixation (LPF) = 16, coracoclavicular ligament reconstruction (CCLR) = 12, and LPF + CCLR = 6. Patients having LPF had a significantly larger post-operative coracoclavicular distance (7.6 mm vs 13.5 mm, p < 0.01), and trends towards a lesser decrease in CCD (9.9 mm vs 12.6 mm, p = 0.37) and incomplete ACJ reduction (50.0% vs 89.3%, p = 0.11). There was a significantly higher re-operation rate after HPF (100% vs 23.5%, p < 0.01). There were no differences in time to union or duration of follow-up. CONCLUSION: In our unit there is no clearly favoured method of internal fixation of lateral clavicle fractures. When LPF is used, there should be consideration of concomitant CCLR. The high rate of re-operation after HPF is concordant with previous research.

Reconstruction of the coracoclavicular ligament with palmaris longus tendon and Mersilene tape for acromioclavicular dislocations.

BACKGROUND: Acromioclavicular (AC) joint dislocation is common among shoulder injuries, and various surgical methods have been introduced for effective ligament reconstruction. Reconstruction of the coracoclavicular (CC) ligament in the anatomical position using autologous tendons is a recent surgical trend. This study is to report clinical and radiologic results of reconstruction of the CC ligament using an autologous palmaris longus tendon interweaved with Mersilene tape (PLMT) with a minimum 2-year follow-up. METHODS: This retrospective study analyzed 76 patients (mean age, 43.4 ± 11.2 years) with AC joint dislocation treated by reconstruction of the CC ligament with PLMT, from March 2004 to February 2017. The mean follow-up period was 28 ± 6.7 months (range, 24-66 months). The Visual Analog Scale (VAS) for pain assessment, American Shoulder and Elbow Surgeons rating scale (ASES), and Constant Score (CS) were used to evaluate clinical outcomes at the preoperative and the final follow-ups. CC and AC distances were measured using anteroposterior (AP) X-ray preoperatively and at the final follow-up for radiologic outcomes. Complications were also assessed. RESULTS: The mean preoperative VAS for pain, ASES, CS were 5.7 ± 0.7, 77.1 ± 6.2, and 61.5 ± 5.2, respectively. These scores at the final follow-up improved to 2.1 ± 0.5, 90.9 ± 4.3, and 94 ± 7.0, respectively (p = 0.043, p <  0.001, p <  0.001). The mean preoperative CC and AC distances were 16.49 ± 3.73 mm and 13.84 ± 3.98 mm, respectively. The final follow-up CC and AC distances were 9.29 ± 2.72 mm and 5.30 ± 2.09 mm, respectively (p <  0.001, p <  0.001). Although a slight re-widening of the CC distance occurred in 10 patients (13.1%), most patients regained full range of motion of the affected shoulder at the final follow-up. CONCLUSION: The CC ligament reconstruction with PLMT for the treatment of AC joint dislocation showed good clinical and radiological results. This technique could be a good alternative treatment for AC dislocations.

Conversion to anatomic coracoclavicular ligament reconstruction (ACCR) shows similar clinical outcomes compared to successful non-operative treatment in chronic primary type III to V acromioclavicular joint injuries.

PURPOSE: To compare the clinical outcomes of patients who underwent successful nonoperative treatment for type III-V acromioclavicular joint (ACJ) injuries to those who eventually required conversion to anatomic coracoclavicular ligament reconstruction (ACCR) at a minimum 5-year follow-up. METHODS: Patients with primary, chronic type III-V ACJ injuries who either underwent successful conservative treatment or conversion to ACCR after failing a trail of conservative management between 2003 and 2014 with a minimum 5-year follow-up were included in the study. Clinical outcome measures comprised the American Shoulder and Elbow Surgeons (ASES) and Simple Shoulder Test (SST) score, collected preoperatively and at final visit for the ACCR group. Outcome scores for patients with successful conservative treatment were only collected at final visit. A Self- Assessment Numeric Evaluation (SANE) score was obtained at terminal follow-up for both groups. RESULTS: Twenty-two patients (mean age: 40.1 ± 15.6 years) with successful nonoperative treatment and twenty-one patients (mean age: 43.6 ± 12.0 years) who required conversion to ACCR were included in the study. At final follow-up, patients with successful non-operative treatment achieved similar ASES (93.0±12.0NonOP vs. 86.1±16.8ACCR), SST (11.2±1.4NonOP vs. 10.7±2.0ACCR) and SANE scores (80.9±19.7NonOPvs. 90.5±14.7ACCR) compared to those who were converted to ACCR. Additionally, patients who underwent conversion to ACCR showed significant improvement in ASES (49.8±18.1pre vs. 86.1±16.8post; Δ36.3±19.7) and SST scores (6.5±3.2prevs. 10.7±2.0post; Δ4.2±4.0) from pre- to postoperative. CONCLUSION: At a minimum 5-year follow-up, patients with successful non-operative treatment for type III-V ACJ injuries achieved similar clinical outcomes compared to those who were converted to ACCR. In patients with chronic severe ACJ dislocation a trial of conservative treatment may be attempted, astime from injuryto eventual conversion to ACCR had no significant influence on postoperative clinical outcomes. LEVEL OF EVIDENCE: Level IV.

Anatomic reconstruction of the coracoclavicular and acromioclavicular ligaments with semitendinosus tendon graft for the treatment of chronic acromioclavicular joint dislocation provides good clinical and radiological results.

PURPOSE: To evaluate clinical and radiographic outcomes of anatomical reconstruction of the coracoclavicular and acromioclavicular ligaments with single-strand semitendinosus tendon graft for the treatment of chronic acromioclavicular joint dislocation. METHODS: Patients affected by chronic type III-V acromioclavicular joint dislocations were included. Exclusion criteria were: age under 18 years, concomitant rotator cuff tears, previous surgery to the same shoulder, degenerative changes of the glenohumeral joint, infections, neurologic diseases, patients with a previous history of ligament reconstruction procedures that had required harvesting of the semitendinosus tendon from the ipsilateral or contralateral knee. All patients underwent the same surgical technique and rehabilitation. Primary outcome was the normalized Constant score. Secondary outcomes were: DASH score, radiographic evaluation of loss of reduction and acromioclavicular joint osteoarthritis. RESULTS: Thirty patients with a mean age of 28.9 ± 8.3 years were included. Mean time to surgery was 12.8 ± 10 months. Mean follow-up was 28.1 ± 2.4 months (range: 24-32). Comparison between pre- and postoperative functional scores showed significant clinical improvement (p < 0.001). Time to surgery was independently associated with a poorer Constant score (p < 0.0001). On radiographs, 4 patients (13.3%) showed asymptomatic partial loss of reduction. CONCLUSION: Anatomic reconstruction of coracoclavicular and acromioclavicular ligaments using a semitendinosus tendon graft for the treatment of chronic acromioclavicular joint dislocation provided good clinical and radiological results at minimum 2-year follow-up. LEVEL OF EVIDENCE: Level III.

Radiographic alterations in clavicular bone tunnel width following anatomic coracoclavicular ligament reconstruction (ACCR) for chronic acromioclavicular joint injuries.

PURPOSE: To evaluate tunnel widening and its relationship in loss of reduction and clinical outcomes in patients undergoing anatomic coracoclavicular ligament reconstruction (ACCR) using free tendon grafts for chronic acromioclavicular (AC) joint injuries. METHODS: A retrospective chart review was performed on patients undergoing ACCR for type III-VI AC joint injuries between January 2003 and December 2017. For radiographic analysis, pre- and post-operative coracoclavicular distance (CCD) and tunnel width of the medial and lateral clavicular bone tunnel were measured at the earliest (EPO) and latest postoperative follow-up (LPO). To determine the clinical relevance of improvement in clinical outcome score (American Shoulder and Elbow Surgeons score) substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) thresholds were used. RESULTS: Twenty-four patients with a mean clinical follow-up of 37 ± 35 months (mean age 44.7 ± 13.4) were included in the study. Both the medial (5.6 ± 0.2 mmEPO-6.6 ± 0.7 mmLPO; p < 0.001) and lateral (5.6 ± 0.5 mmEPO-6.8 ± 1 mmLPO; p < 0.001) clavicular bone tunnel showed significant widening from EPO to LPO. There was a significant loss of reduction at LPO (CCDLPO 10.1 ± 4 mm) compared to EPO (CCDEPO: 6.2 ± 3.8 mm) (p < 0.001). No significant correlation between loss of reduction and medial (p = 0.45; r = - 0.06) or lateral (p = 0.69; r = - 0.06) tunnel widening was found. Alterations in tunnel width were shown having no influence on clinical outcomes. CONCLUSION: Patients who underwent ACCR using a free tendon graft for the treatment of chronic type III-VI ACJ injuries showed significant clavicular bone tunnel widening during the postoperative course. No correlation between tunnel widening and loss of reduction was shown with radiographic findings having no influence on clinical benefit and satisfaction. STUDY DESIGN: Case Series; Level of evidence, IV.

Anatomic coracoclavicular ligament reconstruction (ACCR) using free tendon allograft is effective for chronic acromioclavicular joint injuries at mid-term follow-up.

PURPOSE: To evaluate the clinical and radiographic outcomes of patients undergoing anatomic coracoclavicular ligament reconstruction (ACCR) using free tendon allografts for the treatment of chronic acromioclavicular joint (ACJ) injuries with a minimum 1-year follow-up. METHODS: Patients who underwent ACCR for chronic ACJ injuries between 2003 and 2017 were analyzed. Clinical outcome measures included American Shoulder and Elbow Surgeons (ASES), Constant-Murley (CM), Simple Shoulder Test (SST), and Single Assessment Numerical Evaluation (SANE) scores. Radiographic loss of reduction during follow-up was evaluated by calculating the difference (mm) in the coracoclavicular distance (CCD) of the involved side immediately postoperatively and at terminal follow-up. RESULTS: Forty-two patients (mean age: 42.7 ± 12.8 years) were included in the study with an average follow-up of 3.8 ± 3.1 years (range: 1.1-11.5 years). Patients achieved significant improvement in ASES (50.2 ± 20.1 pre to 85.2 ± 16.3 post), CM (60.2 ± 18.5 pre to 88.2 ± 9.1 post), SST (6.1 ± 3.2 pre to 9.5 ± 3.7 post), and SANE (24.0 ± 25.7 pre to 89.0 ± 12.7 post) scores (P < 0.001, respectively). There were no significant differences in functional improvement when comparing type III and V injuries (n.s.). Mean increase in CCD of the involved side from immediately postoperative to final radiographic follow-up was 4.1 ± 3.9 mm, with no significant correlation to clinical outcomes scores. Complications occurred in 33.3% of cases, with postoperative heterotopic ossification being most frequent (14.3%). CONCLUSION: Patients undergoing ACCR using free tendon allografts for chronic ACJ injuries achieved significant improvement in shoulder function at a mean follow-up of 3.8 years. No correlation was observed between the amount of loss of reduction and clinical outcome scores. Free tendon allografts may be a reliable alternative to autografts in the treatment of chronic ACJ dislocations. LEVEL OF EVIDENCE: IV.

Biologic and synthetic ligament reconstructions achieve better functional scores compared to osteosynthesis in the treatment of acute acromioclavicular joint dislocation.

PURPOSE: To systematically review the outcomes of surgical treatments of acute acromioclavicular joint dislocation. METHODS: Studies were identified by electronic databases (Ovid, PubMed). All studies reporting functional and radiological outcomes of surgical treatments of acute 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: One hundred and thirty-three studies were included for a total of 4473 shoulders. Mean age of participants was 36.9 years. Mean follow-up was 42.06 months. Arthroscopy showed better ASES (p < 0.0001) and lower VAS pain score (p = 0.0249) compared to an open approach. Biologic and synthetic reconstructions demonstrated better results over osteosynthesis techniques. Biologic techniques showed overall better Constant (p = 0.0001) and DASH (p = 0.0215) scores, while synthetic reconstruction showed better UCLA score (p = 0.0001). Among suture buttons, triple button showed overall better results in Constant (p = 0.0001) and VAS (p = 0.0001) scores, while better results in DASH score (p = 0.0003) were achieved by 2 double button techniques. Overall, the level of evidence was low. CONCLUSION: Biological and synthetic reconstructions achieved better functional scores compared to osteosynthesis. Among suture buttons, the triple button showed better functional performance. LEVEL OF EVIDENCE: IV.

Comparison of single versus double TightRope system in the treatment of acute acromioclavicular joint dislocation.

BACKGROUND: Reconstruction of the coracoclavicular (CC) ligament using a single TightRope (ST) system has some complications. We attempted to use a double TightRope (DT) system to reduce complications and obtain the ideal therapeutic effect. PURPOSE: This investigation aimed to compare the ST and DT systems in terms of efficacy and safety in treating acromioclavicular (AC) joint dislocation. METHODS: Sixty-six cases of acute AC joint dislocation between January 2013 and January 2018 were retrospectively reviewed. All patients were divided into 2 groups based on treatment with the ST or DT system. Patients were evaluated radiologically and clinically using the Disability of Arm, Shoulder, and Hand, Constant, and visual analog scale scores as clinical outcome measures at 1 day, 3 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years after surgery. The CC distance and displacement ratio were assessed radiologically. RESULTS: The mean follow-up period was 49 months. Satisfactory clinical outcomes were obtained after CC fixation in both groups. No intergroup difference was found regarding the visual analog scale (P = .80), Disability of Arm, Shoulder, and Hand (P = .42), or Constant score (P = .28) at 2 years. However, there was a significant difference in the displacement ratio at 6 weeks (P < .0001), 3 months (P < .0001), 6 months (P < .0001), 1 year (P < .0001), and 2 years (P < .0001) postoperatively between the 2 groups. There were 3 complications in the ST group, including 1 case of secondary coracoid fracture, 1 case of AC joint arthrosis combined with ossification of the CC ligaments, and 1 case of clavicular erosion. All complications occurred in the ST group. CONCLUSIONS: Both surgical methods are effective in treating AC joint dislocation, but the DT system is more reliable for reduction maintenance.

Ligamentous and capsular restraints to anterior-posterior and superior-inferior laxity of the acromioclavicular joint: a biomechanical study.

BACKGROUND: Approximately 9% of shoulder girdle injuries involve the acromioclavicular joint (ACJ). There is no clear gold standard or consensus on surgical management of these injuries, in part perpetuated by our incomplete understanding of native ACJ biomechanics. We have therefore conducted a biomechanical study to assess the stabilizing structures of the ACJ in superior-inferior (SI) translation and anterior-posterior (AP) translation. METHODS: Twenty fresh frozen cadaveric specimens were prepared and mounted onto a robotic arm. The intact native joint was tested in SI translation and AP translation under a 50-N displacing force. Each specimen was retested after sectioning of its stabilizing structures in the following order: investing fascia, ACJ capsular ligaments, trapezoid ligament, and conoid ligament. Their contributions to resisting ACJ displacements were calculated. RESULTS: In the intact native ACJ, mean anterior displacement of the clavicle was 7.9 ± 4.3 mm, mean posterior displacement was 7.2 ± 2.6 mm, mean superior displacement was 5.8 ± 3.0 mm, and mean inferior displacement was 3.6 ± 2.6 mm. The conoid ligament was the primary stabilizer of superior displacement (45.6%). The ACJ capsular ligament was the primary stabilizer of inferior displacement (33.8%). The capsular ligament and conoid ligament contributed equally to anterior stability, with rates of 23% and 25.2%, respectively. The capsular ligament was the primary contributor to posterior stability (38.4%). CONCLUSION: The conoid ligament is the primary stabilizer of superior displacement of the clavicle at the ACJ and contributes significantly to AP stability. Consideration should be given to reconstruction of the ACJ capsular ligament for complete AP stability in high-grade and horizontally unstable ACJ injuries.

Outcomes after locking plate fixation of distal clavicle fractures with and without coracoclavicular ligament augmentation.

BACKGROUND: The need for coracoclavicular (CC) ligament augmentation when performing locking plate fixation of unstable distal clavicle fractures is controversial. The purpose of this study was to compare the results after locking plate fixation for treatment of Neer type-II and type-V distal clavicle fractures with and without suture suspensory augmentation of the CC ligaments. METHODS: This was a retrospective case series of all Neer type-II and type-V distal clavicle fractures treated with locking plates at a single Level I trauma center. Patients were separated into locking plate-only and locking plate with CC ligament augmentation groups. Postoperative complications and fracture healing rates were recorded. Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores were recorded as functional outcomes during follow-up phone interviews. Standard descriptive statistics were performed. RESULTS: Sixteen patients were treated with locking plate fixation-only, and seven patients were treated with additional CC ligament augmentation. There was a similar distribution of Neer fracture types with each group. All fractures in both groups went onto union without loss of reduction or implant failure. There were no cases of infection or wound complications in either group. QuickDASH scores were comparable between locking plate-only fixation (mean 4.1 ± 3.9) and additional suspensory suture fixation (mean 4.5 ± 3.6). CONCLUSION: This comparative study of Neer type-II and type-V distal clavicle fractures demonstrated comparable outcomes after locking plate fixation with and without CC ligament augmentation. CC ligament augmentation may not be necessary when treating unstable distal clavicle fractures if locking plate fixation is used.

Hook plate with or without coracoclavicular ligament augmentation in the treatment of acute acromioclavicular separation.

BACKGROUND: Acromioclavicular (AC) separation can be treated with the use of a hook plate. Some studies have reported that coracoclavicular (CC) ligament augmentation is necessary to reduce the complications of hook plate fixation, whereas others recommend hook plate fixation alone without augmentation. The aim of this study was to compare the results and complications between these two groups. METHODS: This was an observational case-control study. Patients with acute (less than 2 weeks) Rockwood type V AC separation were treated with a hook plate at our hospital. A total of 105 cases received hook plate fixation with CC ligament augmentation (group I), and 112 cases received hook plate fixation without augmentation (group II). Constant-Murley scores were used to evaluate the function before and after implant removal, and radiographs were taken to evaluate the complications. The results and complications were compared between groups. RESULTS: Before removal, the Constant-Murley score was significantly higher in group I (mean, 50.1) than in group II (mean, 42.6) (p = 0.004); however, there was no significant difference between groups at 3 and 6 months after removal. The incidence of significant acromion osteolysis was higher in group II (65/112) than in group I (25/105). Before removal, the patients with significant acromion osteolysis had worse Constant-Murley scores than those of the patients without osteolysis in both groups. The incidence of peri-implant fracture of the hook plate was higher in group II (8/112) than in group I (1/105). CONCLUSION: The patients without CC ligament augmentation had worse functional results before hook plate removal, a higher incidence of radiographic acromion osteolysis, and a higher incidence of peri-implant fractures than those patients with CC ligament augmentation. Therefore, CC ligament augmentation is highly recommended to improve short-term outcomes and decrease complications for Rockwood type V AC separation treated by hook plate.

Sagittal orientation of coracoclavicular ligament reconstruction affects the stability of surgical repair.

BACKGROUND: The variation in the anatomic relationship between the coracoid and the clavicle affects the biomechanical stability of coracoclavicular ligament reconstruction (CCLR). METHODS: Three-dimensional computed tomography reconstruction of 85 patients was analyzed. Anatomic landmarks were used to derive the coracoclavicular sagittal reconstruction angle (sRA). The lateral concave angle, which indicated the shape of the distal clavicle, and the offsets between the clavicle and coracoid were also measured. To investigate the biomechanical effects of the sRA on CCLR, 7 computed tomography scans with different sRAs were 3D printed. Two reconstructions, a single trans-coracoclavicular tunnel and a looped reconstruction technique, were performed sequentially. Models were cyclically loaded at 70 N in the anterior, posterior, and superior directions. RESULTS: The mean sRA was 68° ± 9.3° (range, 47°-85°). The superoinferior offset between the clavicle and the coracoid and the lateral concave angle positively correlated with the sRA (r = 0.359 and 0.837, respectively; P ≤ .001), whereas the anteroposterior offset had a negative correlation (r = -0.925; P < .001). The sRA had a negative correlation with the anterior displacement of the clavicle (rho = -0.96; P < .001) and a positive correlation with the posterior displacement for both surgical techniques (rho = 1.0; P < .001). CONCLUSION: The anatomic orientation of the native coracoclavicular ligaments is highly variable in the sagittal plane. Low sagittal angles can reduce anterior stability, whereas high sagittal angles can reduce posterior stability of CCLR.

Radiological study of the Asian coracoid process and clavicle: Implications for coracoclavicular ligament reconstruction.

PURPOSE: Iatrogenic coracoid and clavicle fracture is a known complication of drilling bone tunnels during anatomic coracoclavicular ligament reconstruction (ACCR). This study aims to measure the dimensions of coracoid process and clavicle in an Asian population to evaluate the suitability of drilling coracoid and clavicle tunnels for ACCR in Asians. METHODS: Width measurements of 196 coracoids and 189 clavicles were obtained after reviewing all computed tomography (CT) scans of the shoulder performed over a 6 years period. Coracoid measurements were made on the CT slice which showed the maximum cross sectional width of the coracoid base. Medial to lateral measurements of the coracoid width were taken on an axial view, 4 mm above the identified junction of the coracoid base and glenoid base. Antero-posterior clavicle width was measured through a point directly above the midpoint of the coracoid and perpendicular to the long axis of the clavicle. RESULTS: The overall mean coracoid width was 14.8 mm ± 2.54 mm (range 9.2-23.3 mm) and clavicle width was 17.1 mm ± 2.72 mm (range 11.1-25.3 mm). CONCLUSION: The Asian coracoid process is smaller than its Western equivalent. More research is required to validate this conclusion as no cadaveric studies with equivalent measurement techniques have been performed on Asians. Given the potentially narrower dimensions of the Asian coracoid process, extra precautions are required to minimize the risk of iatrogenic coracoid and clavicle fractures.

Arthroscopic reconstruction of coracoclavicular ligament by suspensory fixation for management of acute acromioclavicular joint dislocation and MRI follow-up study. / å ³èŠ‚é•œä¸‹å–™é”éŸ§å¸¦é‡å»ºæ‚¬åŠå¼å›ºå®šæ²»ç–—æ€¥æ€§è‚©é”å ³èŠ‚è„±ä½åŠMRI随访.

OBJECTIVES: To explore the safety and effectiveness of arthroscopic reconstruction of coracoclavicular ligament by suspensory fixation to manage the acute acromioclavicular joint dislocation. METHODS: From January 2016 to December 2017, 18 cases of acute acromioclavicular joint dislocation were carried out with arthroscopic reconstruction of coracoclavicular ligament by double Endobutton plate suspensory fixation. Anteroposterior view X-ray plain radiographs were obtained on the second day, 6 months and 12 months after the surgery, MRI was performed in 1 year after operation. Meanwhile, subjective and objective scoring were obtained by Vsual Analogue Scale (VAS), Rating Scale of the American Shoulder and Elbow Surgeons (ASES) and University of California at Los Angeles Shoulder Rating Scale (UCLA). RESULTS: All patients were followed up for 12 to 30 months (an average of 18 months). There was no patient with infection, neurovascular injury, loosening and breakage of internal fixation, re-dislocation of acromioclavicular joint, clavicular fracture, coracoid process fracture, etc. Postoperative X-ray showed that all acromioclavicular joints were completely relocated. The follow-up of MRI after 1 year showed no obvious dislocation of acromioclavicular joint and good recovery of acromioclavicular space. Postoperative shoulder joint function, VAS, ASES, UCLA and acromioclavicular distance were significantly improved compared with those before surgery, with statistically significant differences (all P<0.05). CONCLUSIONS: Arthroscopic reconstruction of coracoclavicular ligament by suspensory fixation to manage the acute acromioclavicular joint dislocation has the advantages of minimal invasive, rapid functional recovery and less complications and satisfactory early clinical results.

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.

Superior clavicle drilling points and fluoroscopic inclination for anatomic coracoclavicular ligament reconstruction: a cadaveric study.

PURPOSE: This study aims to investigate the superior clavicle cortex drilling points and fluoroscopic inclination angles for anatomic tunnel drilling in coracoclavicular ligament reconstruction. METHODS: Twelve cadaveric shoulders with a mean age of 55.9 ± 6.2 years were investigated. Two 2.0 mm Kirschner wires were inserted penetrating the footprint centers of conoid and trapezoid both on the clavicle and coracoid. The location of the Kirschner wires on the superior clavicle cortex was measured. Fluoroscopy was used to obtain three views of shoulder: an anteroposterior, lateral, and cortical ring sign view. Reproducible angles were then recorded. RESULTS: The Kirschner wire penetrating the conoid was located 40.0 ± 3.9 mm from the distal end and 18.1 ± 3.0 mm from the anterior edge of the clavicle. For the trapezoid, the Kirschner wire was located 19.1 ± 3.6 mm from the distal end and 9.9 ± 3.9 mm from the anterior edge. On the anteroposterior view, the conoid was 11.1° ± 10.1° medially and trapezoid was 26.8° ± 11.8° laterally tilted to the glenohumeral joint line. On the lateral view, the conoid was 42.8° ± 15.1° and trapezoid was 15.5° ± 12.0° superiorly tilted to the scapular spine. On the cortical ring sign view, the conoid was 50.8° ± 12.9° and trapezoid was 14.2 °± 11.0° superiorly tilted to the scapular spine. CONCLUSIONS: The superior clavicle cortex drilling points and fluoroscopic inclination angles for anatomic tunnel drilling in coracoclavicular ligament reconstruction were demonstrated. Arthroscopy-assisted anatomic coracoclavicular ligament reconstruction has increased in popularity, and these findings may facilitate a more anatomic approach to coracoclavicular ligament reconstruction.

Outcome of arthroscopy-assisted treatment for distal clavicle fractures.

HYPOTHESIS: The purpose of the present study was described as the arthroscopically assisted procedure that uses a synthetic conoid ligament reconstruction using Zip Tight (Zimmer biomet, Warsaw, USA) and fracture-site fixation with K-wire. Our hypothesis was that this technique provided a satisfactory functional outcome with minimum complication. METHODS: 45 patients underwent operation to treat fractures of the distal clavicle between January 2014 and May 2017. The inclusion criteria were as follows: (1) there is an episode of trauma and it is the first fracture (2) distal clavicle fracture of Neer type IIb with dislocation in image findings. The exclusion criteria were as follows: (1) Neer type I, IIa and III of distal clavicle fracture (2) existing injury of rotator cuff, biceps tendon and labral during the arthroscopic procedure. Based on these criteria, 23 patients were included in this study. Clinical outcome assessments were performed using 1-year postoperative Quick DASH score, Constant-Murley score, ASES score. Radiological outcome consisted of antero-posterior and axillary radiographs. RESULTS: Mean clinical outcomes were as follows: Quick DASH score was 3.8 ± 2.8, ASES score was 92.3 ± 3.2 and Constant-Murley score was 94.1 ± 3.0. It was a highly satisfactory result in all of the score at 1-year follow-up. All patients had achieved radiographic union at a minimum 1-year follow-up. There were no cases of nonunion or osteolysis. CONCLUSIONS: This study demonstrated that the arthroscopy-assisted treatment using Zip Tight and K-wire provided a satisfactory functional outcome with minimum complication with Neer type IIb fractures of the distal clavicle. LEVEL OF EVIDENCE: IV, Case series, Treatment study.

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.