Stabilization of acute, complete acromioclavicular joint dislocations with a new C hook implant

Long-term Clinical Outcomes After TightRope Versus Hook Plate Fixation for Acute Acromioclavicular Joint Dislocation

Background

There is limited information regarding the long-term efficacy of techniques for surgical fixation after acromioclavicular (AC) joint dislocation.

Purpose

To evaluate the efficacy of hook plate (HP) and TightRope (TR) fixation for acute AC joint dislocations by comparing the long-term clinical and radiological patient outcomes.

Study Design

Cohort study, Level of evidence, 3.

Methods

This study retrospectively analyzed data from 61 patients with acute AC joint dislocation between July 2011 and November 2015. The patients were grouped according to surgical procedure: HP (n = 36) and TR (n = 25). Clinical outcomes at final follow-up were evaluated using the visual analog scale (VAS) for pain; the American Shoulder and Elbow Surgery score; the Korean Shoulder Score; and the University of California, Los Angeles (UCLA) shoulder score. Side-to-side coracoclavicular (CC) distance on radiographs, postoperative complications, and the rate of subacromial erosion in the HP group were also assessed between procedures.

Results

The mean follow-up period was 7.0 ± 1.0 years, and there were no significant differences in pain or outcome scores between the HP and TR groups (all P > .05). Forward flexion was better in the TR group (172.6° ± 5.6°) versus the HP group (166.0° ± 10.8°; P = .002). The percentages of patients with a difference in the side-to-side CC distance of <5 mm were 83.3% and 72.0% in the HP and TR groups, respectively (P = .288). Complications were found in 2 patients in the HP group and 1 in the TR group (P ≥ .999). Subacromial erosion was observed in 41.7% of patients after HP fixation, with no difference in VAS pain scores at the final follow-up in patients with versus without subacromial erosion (P = .719).

Conclusion

When comparing HP with TR fixation for the treatment of acute AC joint dislocations, there were no significant differences in functional outcome scores, final CC distance, or complications. Slightly better forward flexion was seen after TR fixation. Subacromial erosion occurred in 40% of patients after HP fixation, but this did not affect long-term VAS pain scores. Both surgical techniques are effective treatment options for AC joint dislocation.

Comparative analysis of a locking plate with an all-suture anchor versus hook plate fixation of Neer IIb distal clavicle fractures

BACKGROUND

The coracoclavicular fixation with suture anchors adds stability to type IIb distal clavicle fractures fixed with a plate and screws when loaded to failure. The purpose of this study was to compare the clinical and radiological outcomes between the use of a locking compression plate (LCP) with all-suture anchor fixation and hook LCP fixation of Neer IIb distal clavicle fractures.

METHODS

A total of 82 consecutive patients who underwent plate fixation for Neer IIb distal clavicle fractures were included. The subjects were divided into two groups: an LCP with all-suture anchor fixation group and hook LCP fixation group. For clinical assessments, the American Shoulder and Elbow Surgeons score, Korean shoulder score (KSS), and Constant score were recorded. A percentage of the coracoclavicular distance (CCD%) was used to evaluate fracture reduction. Typical reported complications, such as secondary dislocation, implant failure or loosening, peri-implant fracture, acromion osteolysis, stiffness, peri-anchor osteolysis, postoperative acromioclavicular joint arthrosis, nonunion, or delayed union, were also analyzed.

RESULTS

There were no differences in the clinical and radiological outcomes at the final follow-up between the two groups. The period for bone union and CCD% showed no significant differences between groups. Stiffness at 3 months after surgery of LCP with all-suture anchor fixation (n = 3, 10.7%) was less than that of hook LCP fixation (n = 17, 31.5%). The complication rate also showed no significant differences between groups. However, LCP with all-suture anchor fixation had anchor-related complications, although it can reduce hook-related complications.

CONCLUSION

LCP with all-suture anchor fixation showed satisfactory outcomes in comparison with hook LCP fixation. In Neer IIb distal clavicle fractures, LCP with all-suture anchor fixation is a useful method for the maintenance of reduction, avoiding implant removal, and hook-related complications. However, anchor fixation should be carefully used, especially in osteoporotic patients or patients with underlying diseases.

LEVEL OF EVIDENCE

Level III, retrospective study.

Comparison of a novel hybrid hook locking plate fixation method with the conventional AO hook plate fixation method for Neer type V distal clavicle fractures

BACKGROUND

The conventional AO hook locking compression plate (LCP) (Synthes, Solothurn, Switzerland) has only three holes for lateral fragments; therefore it is not suitable for use during the fixation of small-comminuted fragments in some cases. Recently, a novel hybrid hook LCP (TDM, Seoul, Korea) was developed to overcome this limitation. Here, we evaluated the clinical and radiologic outcomes of a novel hybrid hook LCP for Neer type V distal clavicle fractures compared to the outcomes of a conventional AO hook plate.

METHODS

Seventy-eight consecutive patients who underwent hook LCP fixation for Neer type V distal clavicle fractures were included. The subjects were divided into 2 groups: the conventional AO hook LCP group and the novel hybrid hook LCP group. For clinical assessments, the American Shoulder and Elbow Surgeons (ASES) score, Korean shoulder score (KSS), and Constant score were recorded. The percentage modified coracoclavicular distance (MCCD %) was used for the evaluation of fracture reduction. Typical reported complications, such as secondary dislocation, implant failure or loosening, peri-implant fracture, acromion osteolysis, postoperative acromioclavicular joint arthrosis, non-union, or delayed union, were also analyzed.

RESULTS

There were no differences in the clinical outcomes (ASES, KSS, and Constant scores) between the two groups. Bone union was achieved in a significantly shorter period in the hybrid hook LCP group (13.6±2.0weeks) than in the AO hook LCP group (17.5±4.8weeks, p<0.001). Consequently, the time to implant removal was also significantly shorter in the hybrid hook LCP group (4.0±0.5months) than in the AO hook LCP group (5.4±1.1months, p<0.001). The MCCD% showed no significant differences between the treatment groups. There was no statistically significant difference in the complication rate between the two groups; however, the hybrid hook LCP fixation resulted in a lower prevalence of hook-related complications.

CONCLUSION

The hybrid hook LCP fixation showed satisfactory clinical and radiologic outcomes in comparison with the AO hook LCP fixation. The hybrid hook LCP is useful for multiple screw fixation of inferior comminuted fragments in Neer type V distal clavicle fractures. The bone union was significantly shorter; thus, the time to implant removal was also significantly shorter.

LEVEL OF EVIDENCE

Level III, Retrospective study.

Comparison of clavicular hook plate with and without coracoclavicular suture fixation for acute acromioclavicular joint dislocation

Objective

The aim of this study was to compare the clinical and radiographic outcomes of clavicular hook plate fixation with and without coracoclavicular (CC) tape augmentation for the treatment of acute unstable AC dislocation.

Methods

We treated 47 patients (31 men and 16 women; mean age: 47 years (range, 21–81)) with unstable acute AC dislocations (Rockwood III–V) and divided them into two groups according to the treatment modality, with hook plate fixation (hook plate group) or hook plate plus CC tape augmentation (combined group). We assessed radiologic findings, such as subacromial osteolysis and AC osteoarthritis. We also evaluated the clinical outcomes using a visual analogue scale (VAS) for pain, as well as the University of California at Los Angeles (UCLA) Shoulder Rating Scale and the American Shoulder and Elbow Surgeons (ASES) Shoulder Score.

Results

We found that the combined group had less subacromial osteolysis upon radiography, although the CC distance was similar in both groups (119 ± 29.7% of contralateral side CC distance in hook plate group versus 119 ± 34.8% in the combined group, p = 0.77). Compared with the hook plate group, the combined group had a lower VAS score (4.5 ± 2.3 in hook plate group versus 2.3 ± 1.4 in the combined group, p < 0.001), better UCLA scores (19.9 ± 4.9 in hook plate group versus 27.2 ± 4.0 in the combined group, p < 0.001) as well as better ASES scores (51.9 ± 17.8 in hook plate group versus 73.8 ± 13.1 in the combined group, p < 0.001) at 3 and 6 months after surgery.

Conclusion

Hook plate fixation plus CC tape augmentation may prevent subacromial osteolysis and yield better short-term functional outcomes.

Level of Evidence

Level III, Therapeutic Study.

Acromioclavicular joint disruptions: A comparison of two surgical approaches 'hook' and 'rope'

INTRODUCTION

Acromioclavicular joint injuries are common shoulder girdle injuries most commonly resulting from a direct blow to the acromion with the arm adducted. Type-I or type-II acromioclavicular joint injuries can be managed with sling immobilization, early shoulder motion, and physiotherapy. The management of type-III injuries remains controversial and is individualized. Type IV and V injuries should be treated surgically. A myriad of surgical techniques for the management of acromioclavicular joint injuries have been reported.

METHODS

We present a comparative study of 76 patients treated with two most common modalities of treatment for AC joint disruption and that is Hook plate stabilisation (n=52) or arthroscopically assisted tight rope stabilisation (n=24). The primary objective was to establish whether hook plate stabilization was superior compared to arthroscopic tight rope fixation in reducing pain and increasing function in the short-term and long-term for patients with AC joint disruptions III-IV. We also wanted to assess how quickly patients returned to their work/job. It was a prospective study, we included all the patients operated between 2008 and 2015 for AC joint disruption by the two shoulder surgeons of our department. All patients followed a strict physiotherapy protocol and were assessed at 6 weeks, 3 months and 12 months. We used the Harm and cost criteria of assessment and the patient specific functional outcome scores.

RESULTS

Both modalities of treatment have high patient satisfaction rate, return to work is faster in tight rope group but after a year both group of patients returned to their premorbid state. Removal of hook plate is not mandatory and lysis of acromion is rare (1% in our series).

CONCLUSION

Despite the fact that both methods yielded similar results and have statistically similar number of complications, the type of postoperative complications was different between groups. The plate group had more postoperative pain and worse function but both aspects improved after plate removal. The rope group had more complex complications including deep infection and recurrence of deformity and fracture. These differences should be taken into consideration when consenting the patient regarding possible treatment.

Acromioclavicular third degree dislocation: surgical treatment in acute cases

Background

The management of acute Rockwood type III acromioclavicular joint (ACJ) dislocation remains controversial, and the debate about whether patients should be conservatively or surgically treated continues. This study aims to compare conservative and surgical treatment of acute type III ACJ injuries in active sport participants (<35 years of age) by analysing clinical and radiological results after a minimum of 24 months follow-up.

Methods

The records of 72 patients with acute type III ACJ dislocations who were treated from January 2006 to December 2011 were retrospectively evaluated. Patients were categorised into two groups. group A included 25 patients treated conservatively, and group B included 30 patients treated surgically with the TightRope™ system. Seventeen patients were lost to follow-up.

All patients were evaluated at final follow-up with these clinical scores: Constant, University of California Los Angeles scale (UCLA), American Shoulder and Elbow Surgeons Scale (ASES) and Acromioclavicular Joint Instability (ACJI) and with a subjective evaluation of the patient satisfaction, aesthetic results and shoulder function. The distance between the acromion and clavicle and between the coracoid process and clavicle were evaluated radiographically and compared with preoperative values. Δ, the difference in mm between the distance at the final follow-up and at T0 in the injured shoulder, and α, the side-to-side difference in mm at follow-up, were calculated. Heterotopic ossification and postoperative osteolysis were evaluated in both groups.

Results

There were no major intraoperative complications in the surgical group. The subjective parameters significantly differed between the two groups. Constant, ASES and UCLA scores were similar in both groups (P > 0.05), whereas ACJI results favoured the surgical group (group A, 72.4; group B, 87.9; P < 0.05). All measurements of radiographic evaluation were significantly reduced in the surgical group compared with the conservative group. In group A, we detected calcifications in 30% of patients; in group B we detected two cases of moderate osteolysis and calcifications in 70% of patients.

Conclusion

Although better subjective and radiographic results were achieved in surgically treated patients, traditional objective scores did not show significant differences between the two groups. Our results cannot support routine use of surgery to treat type III ACJ dislocations.

Management of acromioclavicular joint injuries

Acromioclavicular joint injuries are among the most common shoulder girdle injuries in athletes and most commonly result from a direct force to the acromion with the arm in an adducted position. Acromioclavicular joint injuries often present with associated injuries to the glenohumeral joint, including an increased incidence of superior labrum anterior posterior (SLAP) tears that may warrant further evaluation and treatment. Anteroposterior stability of the acromioclavicular joint is conferred by the capsule and acromioclavicular ligaments, of which the posterior and superior ligaments are the strongest. Superior-inferior stability is maintained by the coracoclavicular (conoid and trapezoid) ligaments. Type-I or type-II acromioclavicular joint injuries have been treated with sling immobilization, early shoulder motion, and physical therapy, with favorable outcomes. Return to activity can occur when normal shoulder motion and strength are obtained and the shoulder is asymptomatic as compared with the contralateral normal extremity. The management of type-III injuries remains controversial and is individualized. While a return to the previous level of functional activity with nonsurgical treatment has been documented in a number of case series, surgical reduction and coracoclavicular ligament reconstruction has been associated with a favorable outcome and can be considered in patients who place high functional demands on their shoulders or in athletes who participate in overhead sports. Surgical management is indicated for high-grade (≥type IV) acromioclavicular joint injuries to achieve anatomic reduction of the acromioclavicular joint, reconstruction of the coracoclavicular ligaments, and repair of the deltotrapezial fascia. Outcomes after surgical reconstruction of the coracoclavicular ligaments have been satisfactory with regard to achieving pain relief and return to functional activities, but further improvements in the biomechanical strength of these constructs are necessary to avoid loss of reduction and creep with cyclic loading.

Long-term results of the surgical treatment of type III acromioclavicular dislocations

The purpose of this study was to review the long-term outcomes of a previously reported prospective series of 46 type III acromioclavicular dislocations. These were treated surgically with temporary fixation of the acromioclavicular joint with wires, repair of the acromioclavicular ligaments, and overlapped suture of the deltoid and trapezius muscles. Of the 46 patients, one had died, four could not be traced, and three declined to return for follow-up, leaving 38 patients in the study. There were 36 men and two women, with a mean age at follow-up of 57.3 years (41 to 71). The mean follow-up was 24.2 years (21 to 26).

Patients were evaluated using the Imatani and University of California, Los Angeles (UCLA) scoring systems. Their subjective status was assessed using the Disabilities of the Arm, Shoulder and Hand and Simple Shoulder Test questionnaires, and a visual analogue scale for patient satisfaction. The examination included radiographs of the shoulder.

At a follow-up of 21 years, the results were satisfactory in 35 (92.1%) patients and unsatisfactory in three (7.9%). In total, 35 patients (92.1%) reported no pain, one slight pain, and two moderate pain. All except two patients had a full range of shoulder movement compared with the opposite side. Unsatisfactory results were the result of early redisplacement in two patients, and osteoarthritis without redisplacement in one. According to the Imatani and UCLA scores, there was no difference between the operated shoulder and the opposite shoulder (p > 0.05). Given the same situation, 35 (92.1%) patients would opt for the same surgical treatment again.

Operative treatment of type III acromioclavicular joint injuries produces satisfactory long-term results.

Biomechanical comparison of a modified Weaver-Dunn and a free-tissue graft reconstruction of the acromioclavicular joint complex

BACKGROUND

Most surgical reconstructions of the separated acromioclavicular joint do not address the injured ligaments and capsule of the acromioclavicular joint.

PURPOSE

This study was undertaken to compare the biomechanical characteristics of a modified Weaver-Dunn reconstruction and an intramedullary acromioclavicular joint reconstruction that uses a free-tissue graft for reconstruction of both the coracoclavicular and acromioclavicular ligaments.

STUDY DESIGN

Controlled laboratory study.

METHODS

Each pair of 6 matched pairs of cadaveric shoulders was randomly selected for a modified Weaver-Dunn reconstruction on 1 side and the contralateral side was used for free-tissue graft reconstruction of the coracoclavicular and acromioclavicular ligamentous complexes. Anterior-posterior and superior-inferior acromioclavicular joint translation (in millimeters) was measured with acromioclavicular joint compressions of 10, 20, and 30 N, and with translational loads of 10 and 15 N both before and after acromioclavicular joint reconstruction. Load-to-failure testing was then performed for each construct. Repeated-measures analysis of variance (translational testing) and Wilcoxon signed rank test (load-to-failure testing), both with P = .05, were used for statistical analysis.

RESULTS

Mean anterior-posterior and superior-inferior translation of the intramedullary acromioclavicular joint reconstruction was significantly less than that of the modified Weaver-Dunn under all loading conditions (P < .001 and P = .001, respectively), but was not significantly different from that of the intact state (P = .656 and P = .173, respectively). Although the mean ultimate and yield loads and linear stiffness for the intramedullary acromioclavicular reconstruction were greater than that of the modified Weaver-Dunn reconstruction, this did not reach statistical significance (P = .625, P = .625, and P = .625, respectively).

CONCLUSION

Acromioclavicular joint reconstruction with free-tissue graft for both the coracoclavicular and acromioclavicular ligamentous complexes demonstrates initial stability significantly better than a modified Weaver-Dunn and similar to that of intact specimens.

CLINICAL RELEVANCE

This acromioclavicular joint reconstruction provides the surgeon with a relatively nondestructive option.

Injuries to the acromioclavicular joint

Injuries to the acromioclavicular joint are common but underdiagnosed. Sprains and minor subluxations are best managed conservatively, but there is debate concerning the treatment of complete dislocations and the more complex combined injuries in which other elements of the shoulder girdle are damaged. Confusion has been caused by existing systems for classification of these injuries, the plethora of available operative techniques and the lack of well-designed clinical trials comparing alternative methods of management. Recent advances in arthroscopic surgery have produced an even greater variety of surgical options for which, as yet, there are no objective data on outcome of high quality. We review the current concepts of the treatment of these injuries.

A novel treatment of grade III acromioclavicular joint dislocations with a C-hook implant

INTRODUCTION

This study evaluates the results of the new surgical treatment of complete acromioclavicular (ac) dislocations using coracoclavicular (cc) fixation with a shape memory metal C-hook implant.

MATERIALS AND METHODS

Fifteen patients were prospectively analyzed. They all had a Tossy III ac dislocation due to trauma. The ac ligament was reinserted using a surgical bone anchor, and the position of the joint was restored by fixing it with a C-hook. After 3 months the C-hook was removed. Functional status, symptom severity, X-rays and patient satisfaction were analyzed during clinical control visits. The follow-up time was 1 year.

RESULTS

At 12 weeks, full shoulder function had been achieved by 93% of the patients. The final control visit showed full recovery of active ROM in all patients. Two patients had mild pain during certain movements. X-rays showed the precise anatomical position of ac joint with no statistically significant differences compared to the healthy side. Patient contentment was excellent in 14 cases and satisfactory in one case. The average sick-leave was 58 days, including the removal operation. Minor osteolysis of the clavicle was noticed in two patients.

CONCLUSION

The new C-hook implant provides accurate anatomical reduction, conserves the articular surfaces and enables fast functional recovery with excellent patient contentment. Technically, the implant is easy to use. Based on this study, the C-hook presents a reliable novel treatment option in surgical ac repair.

Computational Studies of Shape Memory Alloy Behavior in Biomedical Applications

Background: Nowadays, shape memory alloys (SMAs) and in particular Ni–Ti alloys are commonly used in bioengineering applications as they join important qualities as resistance to corrosion, biocompatibility, fatigue resistance, MR compatibility, kink resistance with two unique thermo-mechanical behaviors: the shape memory effect and the pseudoelastic effect. They allow Ni–Ti devices to undergo large mechanically induced deformations and then to recover the original shape by thermal loading or simply by mechanical unloading. Method of approach: A numerical model is developed to catch the most significant SMA macroscopic thermo-mechanical properties and is implemented into a commercial finite element code to simulate the behavior of biomedical devices. Results: The comparison between experimental and numerical response of an intravascular coronary stent allows to verify the model suitability to describe pseudo-elasticity. The numerical study of a spinal vertebrae spacer, where the effects of different geometries and material characteristic temperatures are investigated, allows to verify the model suitability to describe shape memory effect. Conclusion: the results presented show the importance of computational studies in designing and optimizing new biomedical devices.