• Clinics in Shoulder and Elbow
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• v.17 no.4
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• pp.159-165
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• 2014

Background: Kirschner's wire (K-wire) transfixation and locking hook plate fixation techniques are widely used in the treatment of acute acromioclavicular joint (ACJ) dislocation. The purpose of this study was to compare the clinical and radiologic outcomes between K-wires transfixation and a locking hook plate fixation technique. Methods: Seventy-seven patients with acute ACJ dislocation managed with K-wire (56 shoulders) and locking hook plate (21 shoulders) were enrolled for this study. The mean follow-up period was 61 months. Results: At the last follow-up, the shoulder rating scale of the University of California at Los Angeles (UCLA) was higher in patients treated with locking hook plate than with K-wires ($33.2{\pm}2.7$ vs. $31.3{\pm}3.4$, p=0.009). In radiologic assessments, coracoclavicular distance (CCD) (7.9 mm vs. 7.7 mm, p=0.269) and acromioclavicular distance (ACD) (3.0 mm vs. 1.9 mm, p=0.082) were not statistically different from contralateral unaffected shoulder in locking hook plate fixation group, but acromioclavicular interval (ACI) was significant difference. However, there were significant differences in ACI, CCD, and ACD in K-wire fixation group (p<0.001). Eleven complications (20%) occurred in K-wire transfixation group and 2 subacromial erosions on computed tomography scan occurred in locking hook plate fixation group. Conclusions: ACJ stabilization was achieved in acute ACJ dislocations treated with K-wires or locking hook plates. Locking hook plate can provide higher UCLA shoulder score than K-wire and maintain CCD, and ACD without ligament reconstruction. K-wire transfixation technique resulted in a higher complication rate than locking hook plate.

• Clinics in Shoulder and Elbow
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• v.19 no.3
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• pp.168-171
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• 2016

Fractures at the lateral end of the clavicle inevitably require surgical treatment as there is high potential for delayed union or nonunion. Acromioclavicular dislocation also requires stable and solid fixation for healing, and surgical treatment is recommended for the maintenance of joint function. The hook plate maintains the biomechanics of the acromioclavicular joint, enabling early range of motion. Therefore, for the past 10 years, the hook plate has been widely used in distal clavicle fractures and acromioclavicular joint injuries. However, the hook plate is associated with several complications, such as proximal clavicle fractures, widening of the hook hole, rotator cuff tear, subacromial impingement, and often acromial fractures. We report on two unusual cases of acromion fracture after hook plate fixation in patients with distal clavicle fracture and acromioclavicular dislocation alongside a literature review.

• Clinics in Shoulder and Elbow
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• v.20 no.4
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• pp.222-229
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• 2017

Background: The purpose of this study was to investigate the outcomes after fixation using a 3.5-mm locking compression plate (LCP) hook plate for isolated greater tuberosity (GT) fractures of the proximal humerus. Methods: We evaluated the postoperative radiological and clinical outcomes in nine patients who were followed up at least 1 year with isolated GT fractures. Using the deltopectoral approach, we fixed the displaced GT fragments with a 3.5-mm LCP hook plate (Synthes, West Chester, PA, USA). Depending on the fracture patterns, the hook plate was fixed with or without augmentation using either tension suture or suture anchor fixation. Results: All the patient showed successful bone union. The mean time-to-union was 11 weeks. The radiological and clinical outcomes at the final follow-up were generally satisfactory. The mean visual analogue scale for pain, the University of California at Los Angeles score, the American Shoulder and Elbow Surgeons score, and the subjective shoulder value were 1.4, 30.3, 84.3, and 82.2%, respectively. The mean active forward flexion, abduction, external rotation, and internal rotation of the shoulder were $156.7^{\circ}$, $152.2^{\circ}$, $61.1^{\circ}$, and the 10th thoracic vertebral level, respectively. Only one patient presented with a postoperative complication of shoulder stiffness. The patient was treated through arthroscopic capsular release on the 5th postoperative month. Conclusions: We conclude that fixation using 3.5-mm LCP hook plates for isolated GT fractures of the proximal humerus is a useful treatment method that provides satisfactory clinical and radiological outcomes.

• Clinics in Shoulder and Elbow
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• v.21 no.3
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• pp.138-144
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• 2018

Background: Subacromial erosion remains a major concern after surgical fixation of acromioclavicular (AC) joint using a clavicular hook plate. To minimize postoperative subacromial erosion, we investigated the structural relationship between distal clavicle and acromion around the AC joint by considering the surgical fixation of the joint using the hook plate technique. Methods: Computed tomography scans of 101 AC joints without any inherent pathology were analyzed. The angle between the distal clavicle and acromion around the AC joint (AC angle), depth of the acromion, differences in height between distal clavicle and acromion (AC height difference), and thickness of distal clavicle and acromion at the AC joint were measured. Descriptive statistics were calculated for each anatomical parameter, and all results were compared between gender groups. Results: The mean AC angle was $17.1^{\circ}$(range, $-8.0^{\circ}$ to $39.0^{\circ}$), and the mean AC height difference was 3.5 mm (range, -0.7 to 8.7 mm). Both factors showed very high variability (coefficients of variation=62.6% and 46.6%, respectively). The mean AC angle was significantly higher in the female gender than in the male gender ($19.8^{\circ}$ vs. $13.8^{\circ}$, p=0.048). The mean acromion thickness and distal clavicular thickness were both significantly thinner in the female group than in the male group (p<0.001). Conclusions: Taken together, we believe our results might be helpful in minimizing postoperative subacromial erosion when performing surgical fixation of the AC joint using the hook plate, and be valuable in improving future design of the hook plate.

• Clinics in Shoulder and Elbow
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• v.26 no.4
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• pp.373-379
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• 2023

Background: The purpose of this study was to determine the association between smoking and clinical outcomes of hook plate fixation for acute acromioclavicular (AC) joint injuries. Methods: This study retrospectively investigated 82 patients who underwent hook plate fixation for acute AC joint dislocation between March 2014 to June 2022. The patients were grouped by smoking status, with 49 in group N (nonsmokers) and 33 in group S (smokers). Functional scores and active range of motion were compared among the groups at the 1-year follow-up. Coracoclavicular distance (CCD) was measured, and difference with the uninjured side was compared at initial injury and 6 months after implant removal. Results: No significant differences were observed between the two groups in demographic factors such as age and sex, as well as parameters related to initial injury status, which included time from injury to surgery, the preoperative CCD difference value, and the Rockwood classification. However, the postoperative CCD difference was significantly higher in group S (3.1±2.6 mm) compared to group N (1.7±2.4 mm). Multivariate regression analysis indicated that smoking and the preoperative CCD difference independently contributed to an increase in the postoperative CCD difference. Despite the radiographic differences, the postoperative clinical outcome scores and active range of motion measurements were comparable between the groups. Conclusions: Smoking had a detrimental impact on ligament healing after hook plate fixation for acute AC joint dislocations. This finding emphasizes the importance of smoking cessation to optimize reduction maintenance after AC joint injury. Level of evidence: III.

• Clinics in Shoulder and Elbow
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• v.19 no.3
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• pp.149-154
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• 2016

Background: The purpose of this study is to compare clinical and radiological outcomes between trans-acromial fixation with Kirschner's wire (K-wire) and AO locking hook plate fixation for acute acromioclavicular (AC) joint dislocation. Methods: This study included 61 patients who underwent either closed reduction and trans-acromial fixation with K-wire (group A, 23 patients) or open reduction and internal fixation with AO locking hook plate (group B, 38 patients). Pain on a visual analogue scale (VAS) score, the University of California Los Angeles (UCLA) shoulder score, the American Shoulder and Elbow Surgeons (ASES) score, and active range of motion (ROM) were used in the functional evaluation. For radiological evaluation, coracoclavicular distance (CCD) was measured on both clavicular anteroposterior view and compared between groups. Results: At one-year follow-up, no significant differences in VAS pain score, UCLA shoulder score, ASES score, and active ROM were observed between groups, despite five cases (22.7%, 5/23) of complication in group A. The side-to-side difference between normal and affected CCD was $2.4{\pm}2.2mm$ in group A and $0.2{\pm}0.7mm$ in group B. This difference showed a statistical significance between groups (p<0.001). Conclusions: For the treatment of acute AC joint dislocation, the K-wire trans-acromial fixation group showed a significantly greater CCD than the AO locking hook plate group. In addition, during the follow-up period, much higher incidence of complication related to implant was observed in the trans-acromial fixation group. Although clinical outcomes between groups were not significantly different, these results should be interpreted carefully.

• Clinics in Shoulder and Elbow
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• v.19 no.4
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• pp.209-215
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• 2016

Background: The purpose of this study was to identify the clinical and radiological outcomes of hook plate fixation for lateral end fracture of the clavicle and acromioclavicular dislocation. Methods: There were a total of 20 cases with lateral end fracture of the clavicle and 16 cases with acromioclavicular dislocation. All patients were evaluated for range of motion, functional score by using Constant score, and American Shoulder and Elbow Surgeons shoulder index at just before implant removal and at final follow-up. Coracoclavicular distance was measured in acromioclavicular dislocation and bony union was evaluated in the lateral end fracture of the clavicle. Results: The clinical outcomes and range of motion were increased at the final follow-up compared with just before implant removal in both the lateral end fracture of the clavicle and acromioclavicular dislocation. In acromioclavicular dislocation, all cases-except one-showed maintenance of reduction after implant removal. Moreover, in the lateral end fracture of the clavicle, all cases-except one-showed bony union. Conclusions: Hook plate fixation in the lateral end fracture of the clavicle and acromioclavicular dislocation resulted in good clinical and radiological results.

• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.123-129
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• 2013

Purpose: The purpose of this study is to compare the clinical and radiological outcomes of two surgical treatments, transacromial pin fixation and hook plate fixation, for unstable distal clavicle fractures. Materials and Methods: Twenty four patients with Neer type II distal clavicle fractures who underwent surgery with transacromial pin fixation (Group I: 12 patients) and hook plate fixation (Group II: 12 patients) were included. Reduction and union were evaluated using plain radiographs. Functional evaluation was performed according to UCLA score and Constant-Murley score at last follow-up. Results: All 24 cases showed bone union. Complete union took an average of 10 weeks for group I and 11.7 weeks for group II. Average UCLA score was 33 (group I) and 32.8 (group II). Average Constant score was 88.5 (group I) and 88.8 (group II). No significant difference for each variable was observed between the two groups. Conclusion: For the surgical treatment of Neer type II distal clavicle fractures, transacromial pin fixation and hook plate fixation are both useful methods.

• Clinics in Shoulder and Elbow
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• v.22 no.3
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• pp.149-153
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• 2019

We experienced acromial erosion and subsequent fracture after the treatment of Rockwood type V acromioclavicular dislocation with hook plate and coracoclavicular ligament augmentation. It was treated by using a surgical technique to address an acromial fracture and subsequent losses of reduction in acromioclavicular joint with two trans-acromial cortical screws (crossbar technique). The reduction state of acromioclavicular joint could be maintained by these two screws. Our crossbar technique could be considered as a good salvage procedure for the reduction loss caused by cutout or significant erosion of acromion after insertion of clavicular hook plate.

• Clinics in Shoulder and Elbow
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• v.21 no.2
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• pp.95-100
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• 2018

Background: The purpose of this study was to evaluate the clinical outcomes and complications of hook plate fixation in acromioclavicular (AC) joint dislocations and distal clavicle fractures. Methods: We retrospectively reviewed a series of 60 consecutive patients with hook plate fixation for AC joint dislocation (group I) and distal clavicle fracture (group II). Groups I and II had 39 and 21 patients, respectively. Clinical results were evaluated using the pain visual analogue scale (VAS), simple shoulder test, and Constant-Murley scores. In addition, subacromial erosion and stiffness were evaluated as complications. Results: At the removal, the pain VAS was $2.69{\pm}1.30$ and $4.10{\pm}2.14$ in groups I and II, respectively, which were significantly different (p=0.003). The simple shoulder test score was $9.59{\pm}1.60$ and $7.81{\pm}2.67$ in groups I and II, respectively, which were also significantly different (p=0.002). Subacromial erosion was significantly more frequent in group II (14/21 patients, 66.7%) than in group I (15/39 patients, 38.5%) (p=0.037), and stiffness was also higher in group II (17/21 patients, 81.0%) than in group I (22/39 patients, 56.4%), but it was not significant. Conclusions: Hook plate fixation showed good clinical and functional results for the treatment of acute unstable AC joint dislocation and distal clavicle fracture. But, in distal clavicle fractures, there are more subacromial erosion and stiffness compare with acute unstable AC joint dislocation.