Os acromiale may be a contraindication of the clavicle hook plate: case reports and literature review

Background

Os acromiale can be potentially missed or misdiagnosed as acromion fracture, and this can affect treatment determination if it is complicated with an ipsilateral shoulder injury. The clavicle hook plate is a widely used technique for distal clavicle injuries, leading to transacromial erosion, particularly when in the presence of os acromiale.

Case presentation

A 70-year-old man and a 78-year-old man who had limited mobility and severe pain in their right shoulders following falls attended the emergency center. Both patients were diagnosed with os acromiale with CT or MRI and acute distal clavicle fracture or acromioclavicular joint dislocation. Following a comprehensive evaluation, os acromiale may limit the application of a clavicle hook plate due to potential transacromial erosion. The distal clavicle fracture with ipsilateral os acromiale received treatment with a volar radius locking T plate, and the acromioclavicular joint dislocation with ipsilateral os acromiale was reconstructed using suture anchors. Both yielded satisfactory outcomes and voided transacromial erosion.

Conclusions

Ipsilateral os acromiale may be a relative contraindication to the clavicle hook plate. An axillary lateral radiograph is recommended to detect potential os acromiale in patients using a hook plate.

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.

Surgery improves the clinical and radiological outcome in Rockwood type IV dislocations, whereas Rockwood type III dislocations benefit from conservative treatment

PURPOSE

Despite the available classifications, diagnostics and treatment of acute acromioclavicular joint (ACJ) injuries are still vague and challenging for trauma and shoulder surgeons. This study aimed to evaluate the dynamic radiographic as well as clinical outcome of operatively and conservatively treated Rockwood (RW) type III and IV ACJ dislocations.

MATERIALS AND METHODS

All patients with RW type III and IV ACJ dislocations between 2009 and 2016 (n = 226) were included in this retrospective data analysis with a prospective follow-up examination. According to their injury classification, patients were subdivided in an operative and conservative treatment group. Examiner blinded clinical evaluation including the constant score (CS), American shoulder and elbow surgery (ASES) score, the acromioclavicular joint instability (ACJI) score, visual analog scale (VAS), bilateral force measurements, and posttraumatic/postsurgical sequelae were assessed. Fluoroscopic evaluations including dynamic stability assessment with functional axillary views were performed for every patient.

RESULTS

For follow-up examination (mean 4.8 years ± 0.3 SEM) 56 patients (29 RW type III, 27 RW type IV) were available. In patients with RW type III ACJ dislocations [operative (n = 10); conservative (n = 19)] prolonged duration of treatment was seen in operatively treated patients (p < 0.05). Clear improvement could be shown for the ACJI score (p < 0.05) and coracoclavicular (CC) and acromioclavicular (AC) distance (p < 0.05) in the operative group. In patients with RW type IV ACJ dislocations [operative (n = 18); conservative (n = 9)] superior clinical results were found in operated patients with highly significant differences for the ACJI score (p < 0.001). Radiographic dynamic horizontal analysis showed nearly normalized anteroposterior translation in operated patients (p < 0.05). No differences were found regarding arthroscopic or open procedures.

CONCLUSION

Accurate diagnostics including sufficient dynamic stability assessment with functional axillary views are strongly advised for patients with ACJ dislocations. Conservative treatment should be recommended for patients with RW type III ACJ dislocations, due to shorter duration of treatment with good clinical results but lacking operative risks. In patients with RW type IV ACJ dislocations, surgical treatment is recommended because of superior clinical and radiological results.

LEVEL OF EVIDENCE

Level III.

Long-term stability of coracoclavicular suture fixation for acute acromioclavicular joint separation

PURPOSE

The optimal (SBJI) surgical treatment for acute acromioclavicular (AC) joint disruption remains controversial. What is being presented is the long-term functional outcomes of a double cross-looped coracoclavicular (CC) suture technique with the intention of restoring both anteroposterior and superior displacement of the clavicle.

METHODS

Between 2007 and 2016, 81 patients underwent surgical reconstruction for acute acromioclavicular joint (AC) disruption in two orthopaedic centers. Two patients died for reasons unrelated to the treatment, and seven missed the final follow-up appointment, leaving 72 patients (67 males; 5 females; age 37 ± 12.4; range 15-64 years) for clinical and radiological assessments. All cases were classified according to the Rockwood classification as type III (n = 34), IV (n = 14) or V (n = 24). The dislocation was repaired with double cross-looped CC fixation using four Ethibond sutures passing underneath the coracoid and through a 4.5 mm drill hole in the clavicle in opposing directions to control both anteroposterior and vertical displacement. Radiological investigation preoperatively and at the last follow-up included anteroposterior and/or Zanca views, axillary or Alexander views, and comparative stress radiography of both AC joints. Patients were evaluated clinically with the Constant-Murley score (CMS) and Acromio Clavicular Joint Instability Score (ACJIS). Loss of reduction, subluxation, CC ligament ossification, post-traumatic arthritis, and peri-implant fractures were also recorded.

RESULTS

Seventy-two patients were available for the last clinical and radiological evaluations. At a median follow-up period of 6.3 ± 2.1 years (range 3-12 years), the CMS and ACJIS were 92.1 ± 7.2 (range 60-100 points) and 90.4 ± 8.6 (range 45-100 points), respectively. Complications included 9 (12.5%) patients with slight loss of reduction, 2 (1.7%) with dislocation recurrence, 1 (1.3%) with superficial infection, 1 (1.3%) with a fracture of the lateral end of the clavicle, and 2 (1.7%) with persistent tenderness in the AC joint. The incidence of periarticular ossification was 22.4% and did not affect the final outcome.

CONCLUSIONS

This technique represents an effective and low-cost treatment for acute AC joint separations.

LEVEL OF EVIDENCE

IV.

Biomechanical analysis of a novel clavicular hook plate for the treatment of acromioclavicular joint dislocation: A finite element analysis

BACKGROUND

Clavicular hook plates are frequently used in clinical orthopedics to treat acromioclavicular joint dislocation. However, patients often exhibit acromial osteolysis and peri-implant fracture after hook plate fixation. To solve the above problems, we developed a novel double-hook clavicular plate and used finite element analysis (FEA) to investigate its biomechanical properties.

METHODS

A finite element (FE) model was constructed and validated. Then, a double-hook clavicular plate, a single-hook clavicular plate, and an anatomical double-hook clavicular plate was implanted into the acromioclavicular joint and fixed with screws in groups 1, 2 and 3, respectively. Finally, a load was applied, and some indicators were recorded and analyzed.

RESULTS

For both the proximal clavicular rotation angle and the distal clavicular displacement, the range of motion in groups 1 and 3 was more than 90% lower than that in group 2. The maximum von Mises stress of the clavicle in groups 1 and 3 was more than 45% lower than that in group 2. The maximum stress of the acromion in group 2 was significantly higher than that in groups 1 and 3, and that in group 3 was less than that in group 1, for both cortical and cancellous bone.

CONCLUSIONS

The double-hook clavicular plate could immediately reconstruct the stability of the acromioclavicular joint, effectively reducing the stress of the bone around the clavicle and screws. Additionally, the double-hook clavicular plate could reduce the peak stress of the acromion and produce a more uniform stress distribution.

Comparison of the Radiological and Functional Results of Tight Rope and Clavicular Hook Plate Technique in the Treatment of Acute Acromioclavicular Joint Dislocation

PURPOSE/AIM

Options for surgery for acromioclavicular (AC) joint dislocation vary considerably. This study aimed to examine the functional and radiological results of patients who were operated on using the tightrope (TR) or clavicular hook plate (CHP) technique in the treatment for AC joint dislocation. Materials and methods: The data gathered from 35 consecutive patients who were operated on for AC joint dislocation were analyzed retrospectively in terms of their radiological and functional outcomes. Results: Thirty-two (91.4%) of the 35 patients were male and 3 (8.6%) were female. Thirty (85.7%) patients were classified as Rockwood type 3 and 5 (14.3%) as type 5. Twenty-one patients operated on using the TR technique were categorized as group 1, and 14 patients treated with the CHP technique formed group 2. Functional results were evaluated using the Constant-Murley shoulder scoring system; no statistically significant difference was observed between type 3 and 5 AC separation (p = 0.337). The mean Constant scores of type 3 and 5 injuries were 82.96 and 88.6, respectively. A significant relationship was noted between reduction quality and functional scores (p = 0.006). Postoperative osteoarthritis was seen in 12 (57.14%) patients in group 1 and 7 (50.00%) patients in group 2. In terms of surgery duration, 50.57 minutes in group 1 and 35.71 minutes in group 2 were noted. A statistically significant difference was found between the two groups in terms of surgery duration (p < 0.05). Conclusions: TR and CHP techniques, which do not differ significantly in terms of their clinical results, can be used safely in the treatment of AC separation.

Is coracoclavicular reconstruction necessary in hook plate fixation for acute unstable acromioclavicular dislocation?

Background

Acromioclavicular joint (ACJ) dislocation is a relatively common shoulder injury. For the treatment of cases of severe ACJ dislocation (Rockwood type III–V), hook plate fixation is an easy-to-master and minimally-invasive approach to surgical intervention. Over stress on the acromion following hook plate fixation often leads to acromial complications such as osteolysis and loss of reduction. We hypothesized that suspensory reconstruction alongside hook plate fixation might provide a superior stability and reduce complications as compared with hook plate fixation alone. The purpose of the study was to assess the clinical and radiographic outcomes of these two surgical modalities.

Methods

We retrospectively enrolled 49 patients with acute ACJ dislocation from May 2010 to December 2018. Among them, 19 patients received hook plate fixation only (HP group), and 19 underwent concomitant hook plate fixation and loop suspension fixation with two mersilene sutures (HM group). The demographic data of the patients were recorded and analyzed. All patients underwent a shoulder X-ray initially, immediately postoperatively, and at 1, 3, 6 and 12 months to measure the relative coracoclavicular distance (rCCD). Clinical assessment of shoulder function outcome was conducted using the Constant Murley Score (CMS); the University of California at Los Angeles (UCLA) Shoulder Score was also measured at the latest follow-up.

Results

There were no significant differences in the demographic data between the two groups. With regards to the CMS and the UCLA score, the HM group and HP group both had excellent outcomes, and no significant differences in scores were observed between groups (CMS: 93.90 ± 6.16 versus 94.47 ± 7.26, p = 0.47; UCLA score: 32.84 ± 2.91 versus 34.32 ± 1.16, p = 0.07). However, the HM group demonstrated substantial superiority in terms of maintenance of the rCCD over the HP group (91.47 ± 27.47 versus 100.75 ± 48.70, p = 0.015). In addition, there was less subacromial osteolysis in the HM group than the HP group (52.6% versus 15.8%, p = 0.038).

Conclusion

Both fixations yielded excellent functional outcomes. However, concomitant hook plate fixation with loop suspensory reconstruction demonstrated the fewer acromion complications and statistical differences in reduction maintenance with less clinical significance.

Young men in sports are at highest risk of acromioclavicular joint injuries: a prospective cohort study

PURPOSE

To study the incidence of acromioclavicular joint injuries in a general population.

METHODS

All acute shoulder injuries admitted to an orthopaedic emergency department were registered prospectively, using electronic patient records and a patient-reported questionnaire. The regional area was the city of Oslo with 632,990 inhabitants. Patients with symptoms from the acromioclavicular joint without fracture were registered as a dislocation (type II-VI) if the radiologist described widening of the joint space or coracoclavicular distance on standard anteroposterior radiographs. Patients without such findings were diagnosed as sprains (type I).

RESULTS

Acromioclavicular joint injuries constituted 11% of all shoulder injuries (287 of 2650). The incidence was 45 per 10⁵ person-years (95% confidence interval [CI] 40-51). 196 (68%) were diagnosed as sprains and 91 (32%) as dislocations. Median age of all acromioclavicular joint injuries was 32 years (interquartile range 24-44), and 82% were men. Thirty percent of all acromioclavicular joint injuries were registered in men in their twenties. Sports injuries accounted for 53%, compared to 27% in other shoulder injuries [OR 3.1 (95% CI 2.4-4.0; p < 0.001)]. The most common sports associated with acromioclavicular joint injuries were football (24%), cycling (16%), martial arts (11%), alpine skiing and snowboarding (both 9%), and ice hockey (6%).

CONCLUSION

Our study suggests that in the general population, one in ten shoulder injuries involves the acromioclavicular joint and young men in sports are at highest risk. A prognostic level II cohort study.

Midshaft clavicle fracture following osteosynthesis with a hook plate: a retrospective case analysis

PURPOSE

The clavicle hook plate has been commonly used to treat distal clavicle fractures and acromioclavicular (AC) joint dislocations; however, midshaft clavicle fracture at the medial end of the hook plate remains an underestimated complication. We aimed to discover the risk factors for this complication and the influence of these risk factors on patients and to suggest preventive surgical techniques.

METHODS

We retrospectively reviewed the records of 150 patients with acute distal clavicle fractures or acute AC joint dislocations treated by internal fixation with a clavicle hook plate. The patient demographics, the occurrence of midshaft clavicle fracture at the medial end of the hook plate, and functional outcomes were analyzed. The functional outcomes were evaluated with the American Shoulder and Elbow Surgeons (ASES) Shoulder Score and grading of the Constant shoulder score after the hook plate was removed.

RESULTS

In total, 17 patients had complicating midshaft clavicle fractures at the medial end of the hook plate. Elderly patients had a higher risk of developing this complication than young patients. The odds ratio was 4.4 (p < 0.05). The average ASES score and grading of Constant score of these patients were 74.1 and 16.3 points, respectively, which were significantly inferior to those of patients without complications (p < 0.001).

CONCLUSION

The incidence of midshaft clavicle fractures following osteosynthesis with a clavicle hook plate was not negligible, especially in elderly patients. This complication may impair shoulder function and quality of life. Awareness of this complication and the risk factors for this complication reminds us to perform such operations with caution.

Migration of K-wire into the cavum pleura after the reduction of acromioclavicular dislocation, a case report and review of literature

INTRODUCTION

The use of K-wire (Kirschner wire) in acromioclavicular dislocation was the first trans-articular fixation technique to be described.

PRESENTATION OF CASE

A 40-years-old man was presented to the emergency room (ER) with shortness of breath. He had a history of acromioclavicular dislocation two years ago, which had been treated using two K-wires and tension band wiring. The plain x-ray revealed left side pneumothorax with K-wire migrated into the left hemithorax. CT scan showed that K-wire migrated into the posterior cavum pleura. A chest tube was then inserted, and the removal of K-wire was performed using thoracoscopic assisted surgery followed by the removal of the remaining K-wire in the left shoulder. Three days post-surgery, the chest tube was removed, and the patient was discharged from the hospital.

DISCUSSION

This technique is easy and cheap, but it can cause lethal complications. K-wire can migrate into the area of vital organs, including the liver, heart, neck lung subclavian artery, and aorta.

CONCLUSION

K-Wire should be used cautiously for treating upper extremity injury, especially acromioclavicular dislocation, due to its lethal complications. This method is outdated and should be restricted as much as possible.

Novel Double Endobutton Technique Combined with Three-Dimensional Printing: A Biomechanical Study of Reconstruction in Acromioclavicular Joint Dislocation

Objective

To reconstruct the acromioclavicular (AC) joint using an adjusted closed‐loop double Endobutton technique via a guiding locator that was applied using three‐dimensional (3D) printing technology. At the same time, the reliability and safety of the novel double Endobutton (NDE) were tested by comparing the biomechanics of this technique with the TightRope (TR) approach.

Methods

This retrospective study was conducted between January 2017 and January 2019. The Department of Anatomy at Southern Medical University obtained 18 fresh‐frozen specimens (8 left and 10 right; 12 men and 6 women). First, the guiding locators were applied using 3D printing technology. After preparation of materials, specimens were divided into an NDE group, a TR group, and a normal group. In the NDE and TR groups, the navigation module was used to locate and establish the bone tunnels; after that, the NDE or TR was implanted. However, the Endobuttons were fixed while pressing the distal clavicle downwards and the length of the loop could be adjusted by changing the upper Endobutton in the NDE group while the suture button construct was tensioned and knotted after pressing down the distal clavicle in the TR. Finally, load testing in anterior–posterior (AP), superior–inferior (SI), and medial–lateral (ML) directions as well as load‐to‐failure testing in the SI direction were undertaken to verify whether the NDE or TR had better biomechanics.

Results

In the load testing, the displacements of the NDE and TR groups in the AP, SI, and ML direction were significantly shorter than those of the normal group (P < 0.05). In the load‐to‐failure testing, the ultimate load of the NDE and TR groups had significantly higher increases than the normal group (722.16 ± 92.04 vs 564.63 ± 63.05, P < 0.05; 680.20 ± 110.29 vs 564.63 ± 63.05, P < 0.05). However, there was no statistically significant difference between the two techniques for these two tests (P > 0.05). In the NDE group, four of six failures were a result of tunnel fractures of the coracoid, while two of six were due to suture breakage. In the TR, three failures were due to coracoid tunnel fractures, one was a result of a clavicle tunnel fracture, and the rest were due to suture breakage. In the normal group, half of the failures were a result of avulsion fractures of the conical ligament at the point of the coracoid process, and the other three were due to rupture of the conical ligament, fracture of the distal clavicle, and fracture of the scapular body.

Conclusion

As for the TR technique, the stability and strength of the AC joint were better in patients who underwent reconstruction using the NDE technique than in the intact state.

Radiographic displacement of acute acromioclavicular joint dislocations fixed with AC TightRope

Background

The arthroscopic approach to acromioclavicular (AC) dislocation with methods such as AC TightRope fixation has reported radiographic failure rates between 18% and 50% with functional results graded as good or excellent. Our objective was to review the outcomes after arthroscopic fixation for acute AC joint dislocation using the TightRope device.

Methods

We reviewed the records of 52 patients, with a mean age of 31 years, who underwent arthroscopic fixation with the TightRope device for acute AC joint dislocation. Outcomes were evaluated using the Constant and University of California, Los Angeles scores. The coracoclavicular (CC) distance before and after surgery was compared by radiography.

Results

The mean follow-up period was 36.7 months (range, 6-65 months). Postoperatively, the mean Constant score was 97.13 and the mean University of California, Los Angeles score was 33.2. The CC distance was maintained in 73% of the patients, whereas partial loss of reduction occurred in 19.2% and failure of reduction occurred in 7.7%.

Conclusion

Arthroscopic fixation using the TightRope device for acute AC joint dislocation achieves satisfactory clinical outcomes. However, CC reconstruction appears to result in subluxation in cases with AC dislocation for a period of more than 10 days.

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

INTRODUCTION

While the management of Rockwood type III injuries is still a topic of debate, high-grade Rockwood type V injuries are mostly treated surgically, to anatomically reduce the acromioclavicular (AC) joint and to restore functionality. In this case report, we present a method for non-operative reduction and stabilization of a high-grade AC joint injury.

CASE

A 31-year-old male orthopaedic resident sustained a Rockwood type V injury during a snowboarding accident. His AC joint was reduced and stabilized with an AC joint brace for six weeks. The brace provided active clavicle depression and humeral elevation. After removal of the brace the AC joint showed a nearly anatomic reduction. Six-month follow-up weighted X-ray views showed an AC joint which had healed in a Rockwood type II position and the patient returned to full pre-injury function with a satisfying cosmetic appearance.

CONCLUSION

Non-operative reduction and stabilization of high-grade AC joint separations seems to be a valuable treatment option. A "closed reduction and external fixation" approach with the aid of a dedicated AC joint brace can reduce the AC joint and keep it in place until ligamentous consolidation occurs, thus improving AC joint stability and cosmetic appearance without surgical intervention.

Surgical treatment of acute and chronic AC joint dislocations: Five-year experience with conventional and modified LARS fixation by a single surgeon

BACKGROUND

Different surgical fixation methods are available for the treatment of acromioclavicular (AC) joint dislocations. The aim of this study was to present the results of five years of experience with the Ligament Augmentation and Reconstruction System (LARS) fixation technique by a single surgeon.

METHODS

A single-center retrospective cohort study was performed. All patients treated for an AC joint dislocation with LARS fixation by the same surgeon between 2012 and 2016 (n = 20) were eligible for inclusion. All these dislocations were unstable injuries, Rockwood type-III or higher, requiring acute or chronic repair. The primary outcome was the QuickDASH score. Secondary outcomes were the Subjective Shoulder Value (SSV), Numerical Rating Scale (NRS) pain score, return to work, complications, and implant removal.

RESULTS

17 patients (85%) were available for final follow-up. The median follow-up was 23 months (IQR; 17─34). The median QuickDASH score was 7 (IQR; 2-18), the median SSV was 90 (IQR; 80-90), and the median NRS pain score was 2 (IQR; 1-3). Patients returned to work after a median of 8 weeks (IQR; 6-12). There was no significant difference in functional outcome scores between acute and chronic repair, or between the conventional and modified LARS fixation groups. There were two major complications requiring revision surgery, one ruptured LARS ligament and one case of deep wound infection. Implant removal was performed in one patient.

CONCLUSIONS

The LARS ligament fixation technique seems to be effective for the treatment of AC joint dislocations, resulting in good short- and mid-term patient-reported functional outcome. LARS fixation might also be an acceptable treatment option for active patients with symptomatic chronic AC dislocations.

LEVEL OF EVIDENCE

Level III, Retrospective Comparative Study, Treatment Study.

Repair of the entire superior acromioclavicular ligament complex best restores posterior translation and rotational stability

PURPOSE

The acromioclavicular ligament complex (ACLC) is the primary stabilizer against horizontal translation with the superior ACLC providing the main contribution. The purpose of this study was to evaluate the specific regional contributions in the superior half of ACLC, where the surgeon can easily access and repair or reconstruct, for posterior translational and rotational stability.

METHODS

The superior half of ACLC was divided into three regions; Region A (0°-60°): an anterior 1/3 region of the superior half of ACLC, Region B (60°-120°): a superior 1/3 region of the superior half of ACLC, and Region C (120°-180°): a posterior 1/3 region of the superior half of ACLC. Fifteen fresh-frozen cadaveric shoulders were used. Biomechanical testing was performed to evaluate the resistance force against passive posterior translation (10 mm) and the resistance torque against passive posterior rotation (20°) during the following the four conditions. (1) Stability was tested on all specimens in their intact condition (n = 15). (2) The ACLC was dissected and stability was tested (n = 15). (3) Specimens were randomly divided into three groups by regions of suturing. Stability was tested after suturing Region A, Region B, or Region C (n = 5 per group). (4) Stability was tested after suturing additional regions: Region A + B (0°-120°), Region B + C (60°-180°), or Region A + C (0°-60°, 120°-180°, n = 5 per group).

RESULTS

The translational force increased after suturing Region A when compared with dissected ACLC (P = 0.025). The force after suturing Region A + B was significantly higher compared to the dissected ACLC (P < 0.001). The rotational torque increased after suturing Region A or Region B compared with dissected ACLC (P = 0.020, P = 0.045, respectively). The torque after suturing the Region A + C was significantly higher compared to the dissected ACLC (P < 0.001).

CONCLUSION

The combined Region A + B contributed more to posterior translational stability than Region B + C or Region A + C. In contrast, combined Region A + C contributed more to posterior rotational stability than Region A + B or Region B + C. Based on these findings, surgical techniques restoring the entire superior ACLC are recommended to address both posterior translational and rotational stability of the AC joint.

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.

Osteomyelitis post acromioclavicular joint reconstruction

Acromioclavicular joint (ACJ) injury is a common shoulder injury. There are various techniques of ACJ reconstruction. Superficial infection after ACJ reconstruction is not an uncommon complication. However, osteomyelitis post ACJ reconstruction has never been highlighted as a possible complication. Our patient is a 31-year-old male who sustained a Rockwood 5 ACJ dislocation and had anatomical ACJ reconstruction with autogenous gracilis and semitendinosus graft. Our technique involved the anatomical reconstruction of the ACJ and the coracoclavicular ligament with the usage of two bioscrews and the temporary stabilisation of the ACJ with two k-wires. As in any orthopaedic surgery, infection is often disastrous especially when the surgery involves implants. It can be disastrous with high morbidity to the patient as well as a costly complication to treat. Therefore, we wish to highlight this case as despite its rarity, osteomyelitis can be devastating to the patient and should be prevented if possible.

Biomechanical comparison of two biplanar and one monoplanar reconstruction techniques of the acromioclavicular joint

INTRODUCTION

The purpose of this proof-of-concept study was to investigate the biomechanical performance of two surgical techniques, namely (1) the double Tight-Rope fixation with an additional acromioclavicular FiberTape fixation (DTRC) and (2) the fixation of the clavicle to the acromion and coracoid in a bipodal manner (Bipod) using a Poly-Tape and FiberTape. Both techniques intend to address vertical and horizontal instability after acromioclavicular dislocation. They were compared with the commonly used (3) double Tight-Rope (DTR) technique, which only stabilizes the clavicle to the coracoid.

MATERIALS AND METHODS

The acromioclavicular joint (ACJ) of 18 composite Sawbone shoulder specimens (6 per reconstruction group) were tested for posterosuperior elongation (70N cyclical load, 1500 cycles), load-to-failure and stiffness.

RESULTS

After 1500 cycles, the DTRC, Bipod and DTR group showed an elongation of 0.45 mm (SD 0.14 mm), 1.19 mm (SD 0.54 mm), and 0.46 mm (SD 0.15 mm), respectively. Although the elongation of the Bipod group was increased when compared to the other two groups (Bipod versus DTRC p = 0.008; Bipod versus DTR p = 0.006), the difference was less than 0.7 mm. The DTRC showed a higher load-to-failure of 656.1N (SD 58.1 N) compared to the Bipod [531.1 N (SD 108.2N) (p = 0.039)] and DTR group [522.8 N (SD 32.8 N) (p = 0.033)].

CONCLUSION

The DTRC and the DTR group resulted in similar low elongation, while the elongation in the Bipod technique was slightly higher. Even though this difference of 0.7 mm shows statistical significance, it most likely has no clinical relevance. When testing in posterosuperior direction, which is the clinically relevant load vector, an additional fixation of the clavicle to the acromion did not reduce elongation in this study. It is, furthermore, questionable if the benefit of an increased load-to-failure in combination with no improvement in elongation and stiffness as seen in the DTRC group outweighs the possible risks and increased costs coming with the DTRC refixation.

Three intrasubstance failures of a LARS™ ligament used for ligament reconstruction

We report three cases of intrasubstance failure of a LARS™ (Ligament Augmentation and Reconstruction System) artificial ligament used for acromioclavicular joint reconstruction. The LARS™ ligament failed within four months of the index procedure. All patients underwent a revision procedure following an unsuccessful trial of conservative management. A modified second loop technique was employed during the revision procedure for all cases using the LARS™ ligament. All three patients achieved full recovery to pre-injury level function.

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).

Analysis of the bony geometry of the acromio-clavicular joint

Background

The primary goal of this study was to analyse the anatomic configuration of the acromio-clavicular joint in a healthy population to be able to develop a classification in a second step. On the basis of the primary findings a secondary goal was to find potential clinical indications in refer to AC-joint dislocation and lateral clavicle fractures.

Methods

The upper thoracic aperture including both shoulder joints as well as both sterno-clavicular joints was retrospectively reformatted in a bone kernel in axial orientation with 0.6 mm slice thickness out of existing multiple trauma or post mortem computed tomography (CT) scans. The DICOM data was converted into the STL file format using a three dimensional (3D) reconstruction software (Smartbrush, Brainlab, Feldkirchen, Germany). The data analysis was performed using a 3D—Computer Aided Detection (CAD) Software (BioCAD, Technical University Munich, Germany). For the analysis, the angle between the cranial surface of the acromion and the tangent to its articular surface was evaluated. Accordingly, the angle between the cranial surface of the clavicle and the tangent to its articular surface was assessed.

Results

Overall CT-datasets of 80 healthy patients (40 males, 40 females, mean age 45 ± 8 years) were enrolled and evaluated regarding the configuration of the AC-joint. In this context, three statistically significant (p < 0.001) different configurations of the AC-joint in terms of overhanging acromion, neutral type, overhanging clavicle were identified. The “overhanging acromion” type of AC-joint configuration turned out to be the most common type (46.2%) followed by the “neutral type” (38.4%) and finally the “overhanging clavicle type” (15.4%).

Conclusions

We assume that the shown differences of the AC joint congruency might play an important role in the development of different shoulder injuries resulting from the similar trauma mechanism. However, the proof of these assumptions will be the focus of future studies.

A novel hybrid fixation (coracoclavicular screw supplemented with K-wire) for the treatment of acute acromioclavicular joint dislocation: A prospective study

OBJECTIVE

The aim of this study was to compare the radiological and clinical outcomes of clavicular hook plate fixation and the coracoclavicular lag screw supplemented with K-wire fixation in the treatment of acute acromioclavicular joint dislocation.

METHODS

Between January 2012 to December 2015, 81 patients with acute acromioclavicular joint dislocation were included in this prospective study. 43 patients were treated with clavicular hook plate fixation (Group A) and 38 patients were treated with coracoclavicular lag screw supplemented with K-wire fixation (Group B). Incision length, operation duration, blood loss volume, intraoperative fluoroscopy times and length of hospitalization were recorded. Radiographic outcomes, functional outcomes and complications were also recorded.

RESULTS

Both two groups could achieve good radiographic and functional outcomes after operation. Group B exhibited significantly shorter operation duration, shorter length of incision, less blood loss volume and shorter length of hospitalization than Group A (P < 0.001). In addition, significant difference could be found between the two groups regarding the VAS scores three month postoperatively and the final follow-up (P < 0.001). However, there was no significant difference in radiographic and functional outcomes between the two groups (P > 0.05).

CONCLUSION

The two groups can both achieve satisfactory radiological and functional outcomes in treating acute AC joint dislocation. However, CC screw fixation supplemented with K-wire exerts some advantages regarding the incision length, operation duration, blood loss volume, length of hospitalization. Furthermore, it can better relieve the pain caused by dislocation. Therefore, the novel hybrid fixation (CC screw fixation supplemented with K-wire) provides an alternative treatment for acute AC joint dislocation.

Percutaneous minimally invasive repair of acromioclavicular joint dislocation using cannulated screws under ultrasonic vs. C-arm navigation: A prospective trial

INTRODUCTION

To compare percutaneous minimally invasive repair (PMIR) of acute acromioclavicular (AC) joint dislocation under ultrasound guidance (PMIR-UN) vs. C-arm navigation (PMIR-CN).

HYPOTHESIS

PMIR-UN has similar functional and radiographic outcomes as PMIR-CN.

MATERIALS AND METHODS

We treated 48 patients with acute grade III or V AC joint dislocation with surgical reduction and fixation with Kirschner wires and cannulated screws. The patients were randomly divided into a PMIR-UN group (n=24) and a PMIR-CN group (n=24). We assessed functional outcomes, operative duration, incision length, and intraoperative radiation exposure. Shoulder joint function was evaluated with the Constant-Murley score, and postoperative efficacy was evaluated using the Karlsson criteria.

RESULTS

The median follow-up duration was 13 months (range, 8-18 months). Satisfactory functional outcomes were obtained in both groups. Incision length, incidence of postoperative infection, pin migration, and postoperative efficacy did not differ between the two groups. Operative duration and intraoperative radiation dose were significantly greater in the PMIR-CN group than in the PMIR-UN group (P<0.05). Kirschner wires were removed at 4 weeks after surgery, and cannulated screws were removed at 12 weeks after surgery in both groups.

DISCUSSION

Based on the satisfactory results obtained in all patients, we conclude that PMIR-UN is a safe, easy, and reliable technique for the treatment of acute grade III or V AC joint dislocation.

TYPE OF STUDY

Low-powered prospective randomized trial.

LEVEL OF EVIDENCE

Level II.

Treatment of AC dislocation by reconstructing CC and AC ligaments with allogenic tendons compared with hook plates

BACKGROUND

The purpose of this study was to compare outcomes between allograft reconstruction and hook plate fixation for acute dislocation of the acromioclavicular joint with a minimum 2-year follow-up.

METHODS

A retrospective comparative study of patients treated for acute acromioclavicular joint dislocation from February 2010 to December 2014 in our hospital, consisting of 16 patients who were followed-up, was performed. Eight patients were treated for acute AC dislocation and underwent surgical reconstruction as follows: the coracoclavicular and acromioclavicular ligaments were reconstructed with the allogenic tendon. The other eight patients were treated with hook plates to maintain the AC joint reset. At the latest follow-up, radiographic analysis and the Constant and University of California-Los Angeles (UCLA) scores were used to evaluate shoulder function. The satisfaction of the patients in terms of the efficacy and visual analog scale (VAS) data were also recorded.

RESULTS

After an average follow-up of 30.3 months (range 24-46 months), no patient had dislocated their joint again at the final follow-up based on X-ray examination. The Constant score was 94.4 for the allogenic tendon group and 93.8 for the hook plate group (P = 0.57). According to the UCLA scale (P = 0.23) or VAS (P = 0.16), we found no significant difference between the two groups. All patients reported that they were very satisfied or satisfied with the outcome of surgery, and no significant difference (P = 0.08) was found between the two groups.

CONCLUSIONS

The use of allogenic tendon for reconstruction of the coracoclavicular and acromioclavicular ligaments shows excellent outcomes in terms of the recovery of clinical function or radiographic outcomes for acute AC dislocation. Compared with the hook plate, the hardware did not need to be removed.