Morphological analysis of acromion and hook plate for the fixation of acromioclavicular joint dislocation

Optimizing hook implantation angle of the clavicular hook plate: a cadaveric study

PURPOSE

While Clavicle hook plates have demonstrated favorable results regarding bone and shoulder function, their design can potentially lead to complications due to pressure concentration at the plate's tip. This study aims to investigate the impact of different hook implantation angles on the contact surface area between the hook plate and acromion, with the goal of minimizing mismatch and maximizing contact surface area.

METHODS

Twenty soft shoulder cadavers were included in the study, and the contact surface area of the hook plate was measured in different positions based on the hook implantation angle.

RESULTS

The results showed variations in compatibility, width, and length of the contact surface area depending on the hook implantation angle and the medial or lateral row placement. The lateral row generally demonstrated superior compatibility (84.0% vs 46.67%, p-value < 0.001), with a broader contact area (3.55 ± 0.08 mm vs 3.09 ± 0.10 mm, p-value = 0.004) and a longer contact area (7.36 ± 0.19 mm vs 5.10 ± 0.23 mm, p-value < 0.001) at specific angles. A detailed analysis of the lateral position revealed that the zero angle of implantation resulted in the greatest contact surface area, measuring 3.91 ± 0.70 mm in width (p value = 0.083) and 8.85 ± 1.24 mm in length (p value < 0.001).

CONCLUSION

Placing the hook laterally and at the zero position according to the hook implantation angle can maximize contact surface area, may reduce stress concentration, and minimize complications in hook plate fixation. Further research and consideration of anatomical variations are warranted to refine the placement technique and enhance patient outcomes.

LEVEL OF EVIDENCE

Level V evidence.

Clinical and radiologic outcomes of the modified phemister procedure with coracoclavicular ligament augmentation using mersilene tape versus hook plate fixation for acute acromioclavicular joint dislocation

Background

The clinical superiority of surgical treatment for acromioclavicular (AC) joint dislocation remains controversial. The aim of this study was to compare the clinical and radiological outcomes of the modified Phemister procedure with CC ligament augmentation using Mersilene tape to those of hook plate fixation for acute AC joint dislocation.

Methods

In this study, patients who received modified Phemister surgery with CC ligament augmentation using Mersilene tape (PM group) or hook plate fixation (HK group) for acute unstable AC joint dislocation with a minimum 5-year follow-up period were retrospectively reviewed. The clinical outcomes were evaluated according to blood loss during surgery, surgical duration, visual analogue scale (VAS), Constant-Murley score (CMS), University of California at Los Angeles (UCLA) shoulder rating scale, and the occurrence of complications. Radiological outcomes were assessed from radiographs according to multiple parameters, including CC distance maintenance, acromion osteolysis, and the presence of distal clavicle osteolysis.

Results

A total of 35 patients completed follow-up for more than 5 years and were analyzed in this study (mean = 74.08 months). There were 18 patients in the PM group and 17 in the HK group. The PM group exhibited similar improvement in functional outcome to the HK group. Regarding radiological outcomes, the HK group had a superior performance in terms of CC distance maintenance, of statistical significance (CCDR: 94.29 ± 7.01% versus 111.00 ± 7.69%, p < 0.001) after a one-year follow-up period. However, there were 4 cases of acromion osteolysis and 2 cases of distal clavicle osteolysis in the HK group.

Conclusion

Hook plate fixation was found to be superior to the modified Phemister technique with CC ligament augmentation using Mersilene tape in terms of CC distance maintenance, but there was no significant difference in the functional outcome after 5 years of follow-up. Both surgical methods are reliable options for the treatment of acute AC joint dislocation. Modified Phemister surgery with CC ligament augmentation using Mersilene tape is a relatively lower-cost option for acute AC joint dislocation without the need of a second surgery for implant removal.

Clavicular hook plate for acute high-grade acromioclavicular dislocation involving Rockwood type V: clinical and radiological outcomes and complications evaluation

Background

The surgical treatment of high-grade acromioclavicular joint dislocation remains a matter of debate. Clavicular hook plate internal fixation was widely used in the treatment of acromioclavicular dislocation because of its easy-to-master surgical technique. This study aimed to evaluate outcomes using hook plate fixation for acromioclavicular dislocation.

Methods

A consecutive series of 57 patients with acute acromioclavicular joint dislocation involving Rockwood type V were treated between November 2013 and September 2019 using hook plate fixation. The functional outcomes (using the visual analogue score, Constant-Murley score, and University of California Los Angeles score), the quality of surgical reduction (using the coracoclavicular distance), and post-operative complications were assessed with about 46 months of follow-up.

Results

The mean Constant-Murley score increased from 72.6 before surgery to 87.6 at final follow-up. The mean University of California Los Angeles score was 14.1 pre-operatively and 31.6 at final follow-up. Meanwhile, the visual analogue scores were significantly reduced from 3.4 pre-operatively to 1.3 post-operatively. The coracoclavicular distance decreased from 19.4 mm pre-operatively to 10.9 mm at the last follow-up. Post-operative functional and radiological outcomes were significantly improved compared with pre-operative outcomes (P < 0.01). The overall excellent and good result was 35.1% (20/57) and 54.1% (31/57), respectively. At follow-up, the overall complication rate was 15.8% (9/57) including subacromial impingement (three patients), acromial osteolysis (three patients), reduction loss (one patient), acromioclavicular joint osteoarthritis (one patient), and calcification (one patient).

Conclusion

Hook plate fixation was a viable treatment approach, and achieved good clinical outcomes in the treatment of acute acromioclavicular dislocation involving V. But some complications of hook plate fixation should not be ignored.

Relationship Between Subacromial Bone Erosion and Hook Position of Clavicular Plate in Distal Clavicle Fractures

OBJECTIVES

To evaluate the influence of posterior hook position on subacromial bone erosion during surgical treatment of distal clavicle fractures with locking compression plate clavicle hook plate (CHP).

DESIGN

Single-center retrospective study.

SETTING

Level V trauma center (university hospital).

PATIENTS

Twenty-one patients (mean age, 45.8 years) treated with CHP were included. One, 3, 15, and 2 patients had Neer type I, IIa, IIb, and V fractures, respectively.

INTERVENTION

Open reduction and internal fixation were performed with locking compression plate CHP. All implants were removed after a mean of 6.1 months postoperatively.

MAIN OUTCOME MEASUREMENTS

Japanese Orthopaedic Association shoulder scores were used to assess recovery. Radiographically, the coracoclavicular distance was measured as the distance between the tip of the coracoid process and the undersurface of the clavicle. Three-dimensional computed tomography was performed to identify bone erosion at the hook tips after implant removal. The distance from the acromioclavicular joint center to the bone erosion was divided into 5 areas at 5-mm intervals, and the position and depth of bone erosion were measured in each area.

RESULTS

The mean follow-up period was 17.4 months; mean ± SD Japanese Orthopaedic Association score was 75.9 ± 4.7 at the final follow-up, whereas the mean duration of bony union was 4.4 ± 1.0 (SD) months. Delayed bony union was observed in one patient, whereas a second surgery was required in another due to acromion cut-out. Radiography showed overreduction in 95% of cases. The correlation coefficient showed a difference between coracoclavicular distance and the position of bone erosion measured by CT (Rs = 0.32, P = 0.006). Erosion under the acromion surface was found in all patients. The depth of erosion correlated with the posterior hook position (Rs = 0.29, P = 0.023).

CONCLUSIONS

Posterior hook tip placement increased the likelihood of bone erosion and complications due to overreduction. CHP should be set more anteriorly beneath the acromion to prevent complications.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Subacromial Erosion After Hook Plate Fixation in Acute Acromioclavicular Joint Dislocation

OBJECTIVES

To determine the incidence of subacromial erosion, perform quantitative analysis, and identify risk factors after locking hook plate fixation for acute acromioclavicular joint injury.

DESIGN

A retrospective case series study.

SETTING

A single tertiary university hospital.

PATIENTS/PARTICIPANTS

The study was conducted on 35 patients who had acute acromioclavicular joint injury.

INTERVENTION

Patients underwent the locking hook plate fixation.

MAIN OUTCOME MEASUREMENTS

The computed tomography (CT) was conducted to measure the subacromial erosion. The acromioclavicular slope (AC slope) of the unaffected side, the acromion-hook angle, the acromioclavicular anteroposterior distance (AC-AP distance), and the preoperative acromioclavicular interval of the affected side were analyzed to identify the risk factors of subacromial erosion.

RESULTS

According to the CT findings, subacromial erosion was found in all cases, and the mean value was 5.0 mm, which is 53% of the entire acromion thickness. The AC slope (B = -0.159, P < 0.001) and AC-AP distance (B = 0.233, P = 0.004) were found to have a significant influence on postoperative subacromial erosion. The AC slope showed a negative correlation with the amount of erosion, whereas the AC-AP distance showed a positive correlation with erosion.

CONCLUSION

The CT findings revealed that subacromial erosion occurred in all cases, and the mean erosion depth was about 50% of the acromial thickness. If the preoperative AC slope of the unaffected side was more acute and the AC-AP distance was larger, the incidence of subacromial erosion was higher.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Three-dimensional morphometric analysis of the lateral clavicle and acromion: Implications for surgical treatment using subacromial support

Objectives:

Dislocations and periarticular fractures of the acromioclavicular joint are common injuries of the shoulder girdle. When surgical intervention is indicated, subacromial support is one option to restore the alignment between scapula and the distal/lateral clavicle. Devices used for subacromial support rely on a form of subacromial ‘hook’. The shape, inclination and orientation of which is often mismatched to the anatomy of the inferior surface of the acromion, which may lead to painful acromial osteolysis and rotator cuff abrasion causing impingement. The primary goal of this study was to characterize the geometrical parameters of the acromion and distal clavicle, and their orientation at the acromioclavicular joint.

Methods:

Computed tomography scans of 120 shoulders were converted into digital three-dimensional models. Measurements of the acromion inclination and acromion width relative to the torsional angle as well as the clavicle depth were taken. A numerical optimization of the anatomical parameters (including torsional and inclination angles, height and width) was performed to find the combination of those parameters with the lowest interpatient variability.

Results:

The mean clavicle depth was found to be 11.1 mm. The mean acromion width was 27 mm. The combination of torsional and inclination angles with lowest interpatient variability was found at 80° and 16°, respectively.

Conclusion:

There is a high interpatient variability in the morphology of the inferior surface of the acromion. Subacromial support using a ‘hook’ can be optimized for contact surface area, which should lead to fewer complications after the restoration of acromioclavicular orientation using acromial support strategies.

Clinical and radiological outcome of acute high-grade acromioclavicular joint dislocation: A retrospective cohort study on Hook plate versus arthroscopic assisted single coracoclavicular tunnel with DogBone™ button dual FiberTape® construct

Purpose

Hook plate (HP) is a popular implant of choice in the management of highgrade acute acromioclavicular joint (ACJ) dislocations. Recently, suspensory loop systems have drawn significant interest with comparable results and additionally does not warrant implant removal. However, no studies have compared the outcomes of HP vis-a-vis Dog Bone TM Button with dual FiberTape® (DB).

Methods

38 patients who underwent HP or Arthroscopic assisted single tunnel DB fixation to stabilize high-grade ACJ dislocations were retrospectively included in study for clinically and radiological evaluation at a minimum follow up of one year. American Shoulder and Elbow Society and Constant Murley scores were used for clinical assessment. The radiological evaluation was done by assessing quality of reduction, measuring coracoclavicular distance (CCD), and extent of subacromial erosion.

Results

For final follow up evaluation, both HP and DB group had 16 patients each. The mean follow-up was 55.38 ± 10.9 and 32.88 ± 14.0 months in HP and DB group, respectively. No significant difference in mean ASES (p=0.71) and CM score (p=0.62) was found between the two groups. The DB group revealed higher CCD at the final follow-up compared to the HP group (p=0.01). Although statistically insignificant, there were more subluxations and dislocations in the DB group (37.5%) compared to the HP group (25%). The subacromial erosion was noted in all cases of the HP group at time of implant removal.

Conclusion

Both groups revealed satisfactory functional and radiological outcome. However, the DB group showed a higher tendency of loss of reduction.

Complications and Frequency of Surgical Treatment with AO-Type Hook Plate in Shoulder Trauma: A Retrospective Study

We investigated the complications and frequency of hook plate fixation in patients with shoulder trauma. We reviewed 216 cases of hook plate fixation use at our hospital between January 2010 and May 2020. Finally, we included 76 cases of acute distal clavicle fracture (DCF) and 84 cases of acute acromioclavicular joint dislocation (ACD). We investigated all complications after hook plate use, bony union in the DCF group, and reduction loss in the ACD group. We defined painful shoulder stiffness (PSS) as aggravating resting pain with stiff shoulder, and pain on shoulder elevation (PSE) as continued shoulder pain on elevation without PSS before plate removal. PSS was managed with intra-articular steroid injections or manipulation with or without arthroscopic capsular release (ACR). PSS occurred in 36 and 33 cases of DCF and ACD, respectively. PSE occurred in 17 of 76 fractures and 13 of 84 dislocations. However, no iatrogenic rotator cuff injury was verified by magnetic resonance imaging in patients with PSS or PSE. Subacromial erosion in patients with hook plate fixation should be considered a sequela and not a complication because it is unavoidable in surgery with an AO-type hook plate. The most common complication was PSS, followed by PSE.

Effect of subacromial erosion shape on rotator cuff and clinical outcomes after hook plate fixation in type 5 acromioclavicular joint dislocations: a retrospective cohort study

Background

Surgical fixation using hook plates is widely used in the treatment of acromioclavicular (AC) joint dislocations. The purpose of this study was to evaluate the incidence and shape of subacromial erosions after removal of the hook plate in type 5 AC joint dislocations. Further, we evaluated the effect of the shape of the subacromial erosion on the rotator cuff.

Methods

We retrospectively reviewed 30 patients who underwent hook plate fixation for type 5 AC joint dislocations at our hospital between December 2010 and December 2018. Patients with a follow-up of at least 1 year were included. Clinical outcomes were assessed using the final follow-up Constant-Murley, Korean Shoulder, and visual analog scores. To ensure that the appropriate reduction was well maintained, the coracoclavicular distances of the injured and contralateral sides were evaluated at the last follow-up. Computed tomography was performed to investigate the presence and shape of the subacromial erosion after hook plate removal at 4 months after surgery. Ultrasonography was performed to investigate the presence of rotator cuff lesions at the last follow-up. Clinical and radiological outcomes were compared between groups divided according to the presence and types of subacromial erosions.

Results

Subacromial erosion was observed in 60% of patients (18/30): 13, 2, and 3 simple groove, cave, and marginal protrusion types, respectively. Four patients showed reduction loss at the final follow-up. There were no significant differences in clinical and radiological outcomes between the groups with and without subacromial erosion. Moreover, there were no significant differences between groups according to the types of subacromial erosion. There were no rotator cuff lesions, such as partial tears, in the injured shoulders.

Conclusions

Hook plate fixation may induce subacromial erosions. However, the subacromial erosions caused by the hook plate did not affect the clinical outcomes of type 5 AC joint dislocations. Moreover, regardless of its shape, the subacromial erosion did not affect the clinical outcomes nor cause rotator cuff lesions after plate removal.

Biomechanical testing of three coracoclavicular ligament reconstruction techniques with a 3D printing navigation template for clavicle-coracoid drilling

Background

The identification and precise clavicle-coracoid drilling during coracoclavicular (CC) ligament reconstruction for acromioclavicular (AC) joint dislocation require a high level of experience and surgical skills. Furthermore, the improvement of flexible fixation, such as Endobutton techniques for CC ligament reconstructions is ongoing. We have developed a 3D printing technique navigation template for clavicle-coracoid drilling and a novel implant for the reconstruction. This study aimed to determine the efficiency of the navigation template for clavicle-coracoid drilling and to evaluate the biomechanical performance of the novel CC ligament reconstruction technique.

Methods

A total of 24 fresh-frozen human cadaveric shoulders were randomly assigned to 1 of 3 reconstruction groups or a control group: TightRope, Triple Endobutton, and the Adjustable Closed-Loop Double Endobutton technique. Computed tomography scans, navigation template designs, and 3D printing were performed for the shoulders. Then, AC joint dislocation was simulated in the reconstruction groups, and 3 CC ligament reconstruction techniques were operated via the 3D printing template separately. Furthermore, biomechanical protocols including the translation test (load from 5 to 70 N) and the load-to-failure test were performed to characterize the behaviors and strengths. One-way ANOVA test analyzed differences in displacement under the translation load and the load at failure.

Results

CC ligament reconstructions were performed successfully along with the 3D printing navigation template in the 3 reconstruction groups. During the translation test, no significant difference was found in displacements among the 4 groups. Meanwhile, the mean load of all reconstruction groups at failure (Adjustable Closed-Loop Double Endobutton, 722.1620 N; TightRope, 680.4020 N; Triple Endobutton, 868.5762 N) was significantly larger than the control group (564.6264 N, P<0.05). The Triple Endobutton group had the maximum load at failure (P<0.05), however, no significant difference was noticed between the other 2 reconstruction groups (P>0.05).

Conclusions

The 3D printing navigation template may become helpful and reliable for AC joint dislocation surgery. Among the 3 CC ligament reconstruction techniques, the Triple Endobutton technique has the best strength in terms of biomechanics, while the biomechanical strength of the Adjustable Closed-Loop Double Endobutton technique is reliable in comparison with the TightRope technique.

To explore the reasonable selection of clavicular hook plate to reduce the occurrence of subacromial impingement syndrome after operation

Background

Acromioclavicular joint dislocation is a shoulder joint injury common in the clinical setting and is generally surgically treated with clavicular hook plate technique with confirmed curative effect. However, symptoms such as shoulder abduction limitation, shoulder discomfort and joint pain postoperatively may occur in some patients. Therefore, this study aimed to explore whether the existing clavicular hook plate can be reasonably selected to reduce the incidence of subacromial impingement syndrome (SIS) and provide a reference for clinical diagnosis and treatment.

Materials and methods

Patients with SIS admitted from March 2018 to June 2020 were selected as the experimental group and asymptomatic patients postoperatively, as the control group. The hook end depth and acromial height of the hook plate used in patients were recorded, and the difference between them was calculated.

Results

The difference between the hook plate depth and acromial height was 7.500±1.912 mm and 6.563±1.537 mm in the experimental and control groups, respectively, with statistically significant difference (t=3.021, P=0.006). A difference of >0.6 mm as a grouping index is required to perform a single factor analysis, with statistically significant difference (t=3.908, P=0.048).

Conclusions

The occurrence of SIS after placing the clavicular hook plate may be related to the difference between its depth and the acromial height. A difference of >6 mm may be a factor affecting the occurrence of SIS. Pre-imaging measurement of the acromial height can provide suggestions for selecting the type of hook plate intraoperatively.

Treatment of distal clavicle fracture of Neer type II with locking plate in combination with titanium cable under the guide

To observe and compare the curative effect of a locking plate plus titanium cable under the Guide device and clavicular hook plate in the treatment of Neer type II distal clavicle fractures. A prospective cohort study was conducted to analyse the clinical data of 36 patients with distal clavicle fractures from January 2016 to January 2019. The results were analysed. According to the random number method, the patients were divided into two groups: the titanium cable group (fixed with a titanium cable in combination with a locking plate) and hook plate group (fixed with a clavicular hook plate only). Under the guidance of a special device (for which a patent was obtained), in the titanium cable group, the coracoclavicular ligament was fixed with tension reduction, and then the distal clavicular fracture was fixed with a locking plate. In the hook plate group, the distal clavicle fracture was fixed with a hook plate. The incision length, operation time, bleeding volume and VAS score before, 1 week after and 1 year after the operation were compared between the two groups. The effect of the operation was evaluated by the Constant-Murley score before and 1 year after the operation. X-ray films were taken 2 days, 3 months, half a year and 1 year after the operation to observe the reduction and healing of fractures. At the same time, complications were recorded. The amount of bleeding was the same in the two groups. The operation time in the hook plate group was relatively short, and the difference was statistically significant (P < 0.05). The VAS score in the titanium cable group was significantly lower than that in the hook plate group one year after the operation. The Constant-Murley score in the titanium cable group and hook plate group was significantly higher 1 year after the operation. The number of postoperative complications in the titanium cable group was significantly lower than that in the hook plate group. The treatment of Neer type II distal clavicle fractures with a titanium cable plus a locking plate has a good curative effect, few complications and good postoperative recovery and thus is worth popularizing.

Digital Technology Combined with 3D Printing to Evaluate the Matching Performance of AO Clavicular Hook Plates

BACKGROUND

AO clavicular hook plates have been widely used for treating acromioclavicular (AC) joint dislocation and distal clavicle fractures. Many complications have been reported, and many patients have complained about the discomfort of the plate. However, no study on the impact of clavicular hook plates in AC joint 3D printing models has been reported.

OBJECTIVE

To evaluate the matching performance of hook plates with different hook depths when they were implanted in 3D printing models of normal Chinese AC joints and to propose a further design to achieve a better match.

METHODS

AO clavicular hook plates with two different hook depths of 15 mm and 18 mm were implanted in 3D printing models of forty Chinese normal AC joints. The angle between the distal clavicle and plate (CPA) and the drop between acromion and distal clavicle (ACD) of normal AC joints with and without plates were measured.

RESULTS

Mismatch was found when the hook plates were implanted, with an average CPA of 18.8 ± 5.1° with the 15-mm hook plate and 10.2 ± 4.9° with the 18-mm hook plate. To eliminate the CPA, the ACD decreased by 6.3 ± 1.1 mm with the 15-mm hook plate and 2.9 ± 0.9 mm with the 18-mm hook plate.

CONCLUSIONS

The results revealed that AO clavicular hook plates with different hook depths were very likely to result in over-reduction of the AC joint. It is necessary to bend the hook angle to fit the patient's AC joint to achieve accurate reduction.

Fifteen-degree clavicular hook plate achieves better clinical outcomes in the treatment of acromioclavicular joint dislocation

OBJECTIVE

Clavicular hook plate application is one of the most commonly used treatment methods for acromioclavicular (AC) joint dislocation, although it may cause multiple postoperative complications. We modified the regularly used 0° hook plate to 15° and compared the clinical outcomes of these two hook plates for treatment of AC joint dislocation.

METHODS

Forty-three patients with acute AC joint dislocation were randomly enrolled (0° hook plate, 20 patients; 15° hook plate, 23 patients). The American Shoulder and Elbow Surgeons (ASES) and visual analog scale for pain (VASP) scores were evaluated preoperatively and at 3 days and 1, 2, 3, and 6 months postoperatively and compared between the two groups.

RESULTS

Compared with the preoperative scores, the 6-month postoperative ASES score gradually increased but the VASP score decreased in both groups. Furthermore, the ASES and VASP scores were significantly different between the two groups at every postoperative time point.

CONCLUSION

The 15° hook plate is superior to the 0° hook plate in reducing shoulder pain and improving postoperative recovery in the treatment of AC joint dislocation.

LEVEL OF EVIDENCE

Level III; Treatment study (retrospective comparative study).

Distal Clavicle Fractures: Open Reduction and Internal Fixation With a Hook Plate

Displaced distal clavicle fractures pose unique challenges because of their propensity for instability. In particular, type II fracture patterns are associated with high rates of nonunion with nonoperative management; therefore, surgical fixation is often recommended. Hook plate fixation has demonstrated reliably high rates of osseous union with good functional outcomes. We present our surgical technique and rationale for using a hook plate in the setting of an unstable distal clavicle fracture.

Clinical and Radiological Results of Hook Plate Fixation in Acute Acromioclavicular Joint Dislocations and Distal Clavicle Fractures

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 ± 1.30 and 4.10 ± 2.14 in groups I and II, respectively, which were significantly different (p=0.003). The simple shoulder test score was 9.59 ± 1.60 and 7.81 ± 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.

Predictors of Persistent Pain After Fixation of Distal Clavicle Fractures in an Active Military Population

Patients who undergo open reduction and internal fixation of distal clavicle fractures have a high rate of hardware removal and persistence of symptoms, particularly when attempting to return to high-demand activities. This study evaluated the outcomes of military servicemembers after surgical treatment of distal clavicle fractures. The authors performed a retrospective analysis of active duty servicemembers who underwent open reduction and internal fixation of Neer type II distal clavicle fractures between October 17, 2007, and July 20, 2012, with a minimum of 2-year clinical follow-up. The electronic health record was queried to extract demographic features and clinical outcomes, primarily persistence of pain, removal of hardware, and postoperative return to high-level activity. A total of 48 patients were identified, with mean follow-up of 3.8 years. A total of 44% of patients underwent subsequent hardware removal. All fractures achieved radiographic union, and 35% of patients had persistence of symptoms. Patients who were treated with hook plating had a 3.64-fold higher risk of persistence of pain compared with those treated with conventional plating techniques. A total of 35% of patients successfully returned to full military function and completed a postoperative military deployment. Coracoclavicular reconstruction did not improve outcomes. Persistence of symptoms and requirement for hardware removal were not associated with the rate of postoperative deployment. Achieving excellent functional outcomes with open reduction and internal fixation of distal clavicle fractures remains a challenge. Where possible, conventional plate fixation should be considered over hook plate fixation. However, subsequent hardware removal and continuing shoulder pain do not preclude a return to high-level activity. [Orthopedics. 2018; 41(1):e117-e126.].

New insights in the treatment of acromioclavicular separation

A direct force on the superior aspect of the shoulder may cause acromioclavicular (AC) dislocation or separation. Severe dislocations can lead to chronic impairment, especially in the athlete and high-demand manual laborer. The dislocation is classified according to Rockwood. Types I and II are treated nonoperatively, while types IV, V and VI are generally treated operatively. Controversy exists regarding the optimal treatment of type III dislocations in the high-demand patient. Recent evidence suggests that these should be treated nonoperatively initially. Classic surgical techniques were associated with high complication rates, including recurrent dislocations and hardware breakage. In recent years, many new techniques have been introduced in order to improve the outcomes. Arthroscopic reconstruction or repair techniques have promising short-term results. This article aims to provide a current concepts review on the treatment of AC dislocations with emphasis on recent developments.