Functional reconstruction of chronic acromioclavicular joint separation using a double suture technique combined with semitendinosus autograft.

PURPOSE: We present the functional and clinical results of a combined surgical technique that functionally restores chronic Acromioclavicular Joint Instability (AJI). The method combines a double-looped suture fixation augmented with a semitendinosus autograft. METHODS: Between 2017 and 2021, 15 patients were treated using the surgical technique. All patients suffered an Acromioclavicular Joint Separation that remained untreated for at least 6 (6-16) weeks after the initial injury. Four Ethibond sutures were passed below the coracoid process and through a 4.5 drill hole in the clavicle. The sutures provided adequate horizontal and vertical reduction and stabilization of the clavicle. A semitendinosus autograft was passed below the coracoid process and looped around the clavicle. The remaining graft limbs were used to reconstruct the acromioclavicular capsule. Patients were radiologically evaluated with bilateral anteroposterior (AP), Zanca, and Alexander views. The clinical evaluation was based on the Acromioclavicular Joint Instability Score and the Constant-Murley Score. RESULTS: The mean follow-up period was 31.2 months (17-61). The mean last ACJIS and CMS scores were 96 (90-100) and 97.67 (87-100), respectively. Reduction of the clavicle was radiologically confirmed in all cases throughout the follow-up period. AC arthritis was reported in 1 case without associated clinical symptoms. No significant complications were reported, and all patients returned to the pre-injury activity level. CONCLUSION: The presented functional reconstruction of the AC joint disruption in chronic cases is an effective and secure method with low complication rates and good clinical results. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[Open reduction and internal fixation in treatment of four cases of bipolar clavicle dislocations].

Objective: To summarize the method and effectiveness of open reduction and internal fixation in the treatment of 4 cases of bipolar clavicle dislocations. Methods: Between June 2017 and June 2022, 4 patients with bipolar clavicle dislocations were admitted. There were 3 males and 1 female. The age ranged from 27 to 63 years, with an average age of 45 years. There were 2 cases of crushing injury of mine car, 1 case of traffic accident injury, and 1 case of heavy object injury. The time from injury to operation was 3-7 days, with an average of 5.0 days. The sternoclavicular joint dislocations were classified as Grade Ⅱ in 1 case and type Ⅲ in 3 cases, and anterior dislocation in 3 cases and posterior dislocation in 1 case. The acromioclavicular joint dislocations were classified as Tossy type Ⅱ in 2 cases and type Ⅲ in 2 cases. After open reduction, the sternoclavicular joint and acromioclavicular joint were fixed with lateral malleolus locking titanium plate and clavicular hook plate, respectively. Results: All operations were successfully completed without vascular or nerve injury. All incisions healed by first intention. All patients were followed up 12-18 months, with an average of 14 months. At last follow-up, the shoulder joint functions were rated as excellent in 3 cases and good in 1 case according to Rockwood score. During follow-up, there was no loosening of internal fixator or fracture. The internal fixators were removed in all patients at 5-7 months after operation (mean, 6 months), and no re-dislocation occurred after removal. Conclusion: For bipolar clavicle dislocation, open reduction combined with lateral malleolus locking titanium plate fixation of the sternoclavicular joint and clavicle hook plate fixation of the acromioclavicular joint can achieve good effectiveness. It has the advantages of simple operation, high safety, firm fixation, and fewer complications, and the shoulder function recovers well.

Clavicular tunnel widening after coracoclavicular stabilization surgery: a systematic review and meta-analysis.

BACKGROUND: This systematic review and meta-analysis aimed to (1) estimate the prevalence of clavicular tunnel widening (TW) after coracoclavicular stabilization surgery and its risk factors and (2) assess whether TW is correlated with clavicle fracture or loss of reduction of the acromioclavicular joint (ACJ). METHODS: In January 2023, 3 electronic databases were searched to collect data on postoperative clavicular TW, its prevalence, magnitude, and correlation with fracture and ACJ loss of reduction. Studies were classified according to the time of surgical intervention, and the clavicular tunnels were categorized by their anatomic location. Mean differences were calculated using a DerSimonian-Laird random-effects model, while binomial outcomes were pooled using the Freeman-Tukey double arcsine transformation. Univariate and multivariate meta-regression analyses were performed to determine the effect of several variables on the proportion of cases with TW. RESULTS: Fifteen studies (418 shoulders) were included. At the final follow-up, evidence of clavicular TW was found in 70% (95% confidence interval [CI]: 70%-87%; I2 = 89%) of 221 shoulders. Surgeries in acute cases had a lower prevalence of TW (52%) compared to chronic cases (71%) (P < .001). Significant TW was found in the central tunnel (3.2 mm; 95% CI: 1.8-4.6 mm; P < .001; I2 = 72%) for acute injuries and in the medial (1.2 mm; 95% CI: 0.7-1.7 mm; P < .001; I2 = 77%) and lateral (1.5 mm; 95% CI: 0.7-2.3 mm; P < .001; I2 = 77%) tunnels for chronic cases. Single central-tunnel techniques were positively associated with the prevalence of TW (P = .046), while biotenodesis screw fixation was associated with a lower prevalence (P = .004) in chronic cases. Reconstruction of the ACJ ligament complex with tendon grafts or sutures was associated with a higher prevalence of TW (P < .001). Drill sizes between 2.5 and 5 mm were significantly associated with a lower prevalence of TW, regardless of injury chronicity (P = .012). No correlation was found between TW and the loss of ACJ reduction or clavicle fractures. CONCLUSIONS: This systematic review and meta-analysis explored TW occurrence following coracoclavicular stabilization surgery. TW was observed in 70% of patients at final follow-up, with a higher prevalence in chronic than in acute cases. Modifiable surgical variables, such as single-tunnel tendon graft constructs for acute or chronic injuries and knotted graft procedures for chronic injuries, were significantly associated with TW. Furthermore, the prevalence of TW increased with concomitant surgical treatment of the ACJ ligament complex, and decreased with drill sizes between 2.5 and 5 mm, regardless of lesion chronicity. These surgical variables should be considered when establishing transosseous tunnels for coracoclavicular stabilization. Clavicle fractures and TW mechanisms require further investigation.

Editorial Commentary: Acute Treatment Including Cerclage Result in Best Surgical Outcomes for High-Grade Acromioclavicular Joint Separations.

Despite years of research, optimal treatment of acute high-grade acromioclavicular joint (ACJ) separations remains controversial. ACJ separations occur in a "multiplanar" fashion and identification of horizonal plane instability is paramount to differentiate between high-grade versus low-grade injuries. As surgeons, we treat a self-selected group of patients referred for surgery, and our physiotherapy colleagues may rehabilitate many patients with both "low-grade" and "high-grade" separations who compensate. Of importance, ACJ separations stabilized <3 weeks after injury have the best chance of healing in a close-to anatomic position. The addition of the ACJ cerclage augmentation improves horizontal plane stability while the soft tissues heal and likely improves outcome.

Dynamic Horizontal Instability of the Acromioclavicular Joint: A Case Report.

CASE: A 19-year-old female patient with a history of shoulder trauma 6 years ago presented with dynamic horizontal instability of the acromioclavicular joint (ACJ). She was treated with open ACJ reconstruction using gracilis allograft and showed a satisfactory clinical result at 1-year follow-up. CONCLUSION: Dynamic pure horizontal instability of the ACJ is a rare entity with only 6 cases reported in the literature. Till now, all reported patients who necessitated surgical treatment failed because of residual instability and/or pain. We present the seventh case of this type with a successful clinical outcome.

The importance of a structured failure analysis in revision acromioclavicular joint surgery: A multi-rater agreement on the causes of stabilization failure from the ISAKOS shoulder committee.

BACKGROUND: Acromioclavicular joint (ACJ) stabilizations are associated with a high overall failure rate with 9.5% of these patients requiring subsequent revision surgery. Consequently, understanding the specific cause of primary ACJ stabilization failure is paramount to improving surgical decision-making in this challenging patient cohort. PURPOSE: To (1) identify risk factors and mechanisms for failure following primary arthroscopically-assisted ACJ stabilization to highlight the importance of conducting a detailed failure analysis and to (2) establish revision strategies based on real-life cases of primary failed ACJ stabilization. STUDY DESIGN: Level of evidence IV. METHODS: A survey was shared internationally among members of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) shoulder committee. The survey contained failure analysis of 11 real-life cases of failed primary arthroscopically-assisted ACJ stabilization. For each case, a thorough patient history, standardized radiographs, and CT scans were provided. Participants were asked to give their opinion on bone tunnel placement, cause of failure (biological, technical, traumatic, or combined), the stabilization technique used, as well as give a recommendation for revision. RESULTS: Seventeen members of the ISAKOS shoulder committee completed the survey. Biological failure was considered the most common cause of failure (47.1%), followed by technical (35.3%) and traumatic (17.6%) failure. The majority deemed two modifiable factors (i.e., patient's profession and sport) as well as non-modifiable factors (i.e., patient's age and time from trauma to initial surgery) to be risk factors for failure. In 10 of 11 cases, the correct fixation device was used in the primary setting (90.9%; 52.8-82.4% agreement); however, in eight of those cases, the technique was not performed correctly (80.0%; 58.8-100% agreement). In 8 of all 11 cases, the majority recommended an arthroscopically assisted technique with graft augmentation for revision (52.9-58.8% agreement). CONCLUSION: Biological failure and technical failure are the most common reason for failure in primary ACJ stabilization followed by traumatic failure. Besides, biological failure can be triggered by technical errors such as clavicular or coracoidal tunnel misplacement. Consequently, a detailed failure analysis including preoperative CT should be conducted on the causes of primary ACJ failure, and, if possible, an arthroscopically-assisted technique with graft augmentation should be prioritized in revision ACJ surgery. CLINICAL RELEVANCE: ACJ stabilizations are associated with a high overall failure rate - potentially due to biological and technical properties. When encountering failed arthroscopically-assisted ACJ stabilization, a detailed failure analysis should be conducted on the causes of primary ACJ failure. Furthermore, an arthroscopically-assisted revision stabilization is feasible in most cases.

Optimizing Treatment for Combined Midshaft Clavicle Fracture and Acromioclavicular Joint Injury: A Case Study Highlighting the Efficacy of Knowles Pin Fixation.

BACKGROUND An ipsilateral fracture of the midshaft clavicle with dislocation of the acromioclavicular joint (ACJ) is a rare combination injury and almost always occurs following high-energy trauma. Currently, there is no optimal surgical approach for this kind of rare injury. We present a 60-year-old man with a traumatic combined linear midshaft clavicle fracture and ACJ injury simultaneously treated with Knowles pin fixation. CASE REPORT A 60-year-old male patient presented a linear midshaft clavicle fracture in the emergency room (ER) due to a road traffic accident. A linear fracture progressed to a displaced fracture at followup in the outpatient orthopedic department 3 days later. After open reduction with Knowles pin fixation for displaced clavicle fracture, postoperative followup radiographs revealed unexpected ipsilateral type V ACJ dislocation according to Rockwood classification. The next day, a closed reduction with percutaneous Knowles pin fixation was performed for ACJ dislocation. At the 1-year followup, radiographic and clinical results demonstrated complete union of the clavicle fracture and anatomic reduction of the ACJ with painless and full range of motion. CONCLUSIONS This report highlights that even a linear midshaft clavicle fracture can be combined with ipsilateral ACJ dislocation if the traumatic injury was caused by a high-energy road traffic accident. Therefore, an intraoperative stress view of the injured shoulder is recommended to recheck the stability of the ACJ after the clavicle fracture fixation to prevent a missed ACJ injury. In our case, an excellent outcome was achieved by using Knowles pin fixation simultaneously to treat the dual shoulder injury.

Long-term follow-up in a single-bundle arthroscopic acromioclavicular joint reconstruction after Rockwood III to VI dislocation.

This retrospective study presents the clinical and radiographic results of a single-bundle arthroscopic acromioclavicular joint reconstruction in 45 patients with a mean follow-up of 4.8 years. Patients with a Rockwood grade III or higher were included. Clinical results were based on satisfaction, pain and functional scores. These outcome scores were compared to coracoclavicular distance measurement on X-ray. Secondly, clinical outcome scores were compared between patients who had surgery in the first 6 weeks after trauma and patients treated after 6 weeks. Overall, X-ray showed a good reduction in 71.1% of the patients (less than 50% loss of reduction). These patients showed better clinical results than patients with radiographical failure in terms of satisfaction (p = .001), Constant (p = .001), DASH (p = .031) and SPADI (p = .005) scores. In total, 78% of the patient had surgery in the first 6 weeks after trauma. When treated later (mean time to surgery of 8.8 months), patients showed worse results for satisfaction (p = .003) and DASH score (p = .006), suggesting that treatment of chronic cases might warrant additional fixation techniques. As a conclusion, these results showed that, in the acute approach, single-bundle arthroscopic coracoclavicular fixation is a good treatment in acromioclavicular joint dislocation Rockwood grade III or higher.

Treatment of coracoid process fractures combined with acromioclavicular joint dislocation using clavicular hook plate.

BACKGROUND: The injury mechanism of acromioclavicular (AC) dislocation combined with coracoid process (CP) fracture is not clear, and there is no consensus on its treatment. This study was performed to evaluate the diagnosis of CP fractures combined with AC dislocation and the effectiveness of operative treatment using a clavicular hook plate. METHODS: Eighteen patients with CP fractures combined with AC dislocation were treated with a clavicular hook plate from May 2012 to June 2021. The patients comprised 10 male and 8 female patients with an average age of 38 years (range, 16-54 years). The injury was caused by falling in 15 patients, traffic accidents in 2 patients, and falling from a height in 1 patient. The Eyres type of CP fracture was type II in 1 patient, type III in 11 patients, type IV in 3 patients, and type V in 3 patients. The Ogawa type of CP fracture was type I in 17 patients and type II in 1 patient. The Rockwood type of AC dislocation was type V in 1 patient, variation type III in 15 patients, and variation type V in 2 patients. The interval from injury to the operation was 3 days (range, 1-7 days). Postoperative complications and CP fracture healing were recorded. Functional assessment at the last follow-up was performed by an independent reviewer using the Constant score and visual analog scale score. RESULTS: All 18 patients were followed up for a mean period of 49 months (range, 12-123 months). Nine patients had acromion osteolysis and 3 patients had CP fracture nonunion (Eyres type II, III, and V in 1 patient each); however, no patients developed shoulder pain, incision infection, limitation of shoulder movement, clinical symptoms of subcoracoid impingement, or AC dislocation relapse. At the last follow-up, the mean Constant score was 99 (range, 94-100). CONCLUSIONS: The possibility of CP fracture should be considered in patients with AC dislocation to avoid a missed diagnosis. Fixation with a clavicular hook plate is a feasible treatment for CP fracture combined with AC dislocation and provides a satisfactory outcome. CP fracture healing may be related to the fracture morphology.

Clavicular hook plate versus dog-bone technique for acute high-grade acromioclavicular joint dislocation: a retrospective cohort study comparing clinical outcome scores, complications, and costs.

INTRODUCTION: Arthroscopically assisted coracoclavicular (CC) ligament fixation techniques have been promoted as providing superior outcomes for the treatment of acute high-grade acromioclavicular joint (ACJ) dislocations. Nevertheless, there is a lack of high-level evidence for clinically relevant benefits. At our institute, orthopaedic surgeons use an arthroscopically assisted coracoclavicular ligament fixation technique (DB), while general trauma surgeons use a clavicular hook plate (cHP) technique. The aim of the study was to compare clinical outcomes, complication rates, and costs between the two groups. MATERIALS AND METHODS: The hospital database was searched for patients treated for acute traumatic high-grade (Rockwood Typ ≥ III) ACJ dislocation using either a cHP or arthroscopically assisted DB technique between 2010 and 2019. Seventy-nine patients could be included (56 patients in the cHP group and 23 in the DB group). QuickDASH scores, subjective shoulder value (SSV) scores, pain scores (numerical pain rating scale 10), and complication rates were retrospectively collected through phone interviews and by screening patient charts as well as surgical reports. Costs per patient were obtained from the hospital's accounting system. RESULTS: Mean follow-up was 54 ± 33.7 and 45 ± 21.7 months in the cHP and DB group, respectively. QuickDASH and SSV scores did not differ, but patients in the cHP group reported significantly lower pain scores (p = 0.033). More patients reported hypertrophic or disturbing scars (p = 0.49) and sensibility disturbances (p = 0.007) in the cHP group. Three patients suffered from a frozen shoulder in the DB group (p = 0.023). CONCLUSION: Patient-reported outcomes are excellent after long-term follow-up for both techniques. There are no clinically relevant differences in clinical outcome scores based on our results and a review of the literature. Both techniques certainly have their benefits regarding secondary outcome measures. LEVEL OF CLINICAL EVIDENCE: Level 3, retrospective cohort study.

Complications after operative treatment of high-grade acromioclavicular injuries.

BACKGROUND: Treatment of Rockwood type III-V acromioclavicular (AC) joint injuries remains controversial. Numerous reconstruction techniques have been proposed. The purpose of this study was to describe the complication profile in a large cohort of patients who underwent surgical management of AC joint separations using a variety of reconstruction strategies. METHODS: All patients who underwent surgery for AC joint injuries from 2013 to 2019 at a single institution were identified. Chart review was performed to capture patient demographics, radiographic measurements, operative techniques, postoperative complications, and revision surgery. Structural failure was defined as a radiographic loss of reduction of greater than 50% when comparing immediate and final postoperative imaging. Logistic regression analysis was performed to identify risk factors for complications and revision surgery. RESULTS: Of the 279 patients included in the study, 66 (24%) had type III separations, 20 (7%) type IV, and 193 (69%) type V. Fifty-three percent underwent surgery acutely (<6 weeks of injury), and 40% were chronic (>3 months). A total of 252 of the 279 surgeries (90%) were performed open and 27 (10%) were arthroscopically assisted. Allograft was used in 164 of 279 (59%) cases. Specific operative techniques (with or without allograft) included hook plating (1%), modified Weaver Dunn (16%), cortical button fixation (18%), and suture fixation (65%). At mean 28-week follow-up, 108 complications were identified in 97 patients (35%). Complications were identified at mean 20 ± 21 weeks. Sixty-nine structural failures (25%) were identified. Persistent AC joint pain requiring injection, clavicle fracture, adhesive capsulitis, and hardware complications were the other most common complications. Twenty-one patients (8%) underwent unplanned revision surgery at mean 38 ± 28 weeks after the index procedure, with the most common indication for structural failure, hardware complications, or fracture of the clavicle or coracoid. Patients who had surgery after 6 weeks from injury had a significantly greater risk of having a complication (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.34-7.77, P = .009) and a significantly greater risk of having structural failure (OR 2.65, 95% CI 1.38-5.28, P = .004). Patients who had an arthroscopic technique had a greater risk of structural failure (P = .002). Complications, structural failure, and revision surgery were not significantly correlated with use of allograft or specific operative techniques. CONCLUSION: Surgical management of AC joint injuries is associated with a relatively high complication profile. Loss of reduction in the postoperative period is common. However, the revision surgery rate is low. These findings are important for patient preoperative counseling.

[Application of TightRope system combined with Locking-Loop biplane anatomical reconstruction technique for acute acromioclavicular joint dislocation].

Objective: To investigate the effectiveness of TightRope system combined with Locking-Loop biplane anatomical reconstruction technique in the treatment of acute acromioclavicular joint dislocation. Methods: A clinical data of 28 patients with acute acromioclavicular joint dislocation who met the selection criteria and admitted between June 2018 and December 2021 was retrospectively analyzed. There were 18 males and 10 females, with an average age of 47.7 years (range, 22-72 years). The causes of injury included falling (13 cases) and traffic accidents (15 cases). The acromioclavicular joint dislocation was rated as Rockwood type Ⅲ in 7 cases, type Ⅳ in 16 cases, and type Ⅴ in 5 cases. The time from injury to operation was 4-13 days, with an average of 9.5 days. The acromioclavicular joint dislocation was reconstructed with TightRope system and high-strength wire by Locking-Loop methods during operation. The operation time and complications were recorded. Visual analogue scale (VAS) score, Constant-Murley score, and active range of motion of shoulder (forward flexion and upward lift, abduction and upward lift, and external rotation) were recorded before operation and at 12 months after operation to evaluate the functional recovery of shoulder. The loss of acromioclavicular joint reduction was assessed by comparing the coracoclavicular distance (CCD) based on the anteroposterior X-ray films at 3 days and 12 months after operation. Results: The operation time was 58-100 minutes (median, 85 minutes). All incisions healed by first intention. All patients were followed up 12 months. During follow-up, 2 patients developed shoulder adhesion, which recovered after rehabilitation exercise. At 12 months after operation, the VAS score was significantly lower, the Constant-Murley score was significantly higher, and the range of motion of the shoulder joint (forward flexion and upward lift, abduction and upward lift, and external rotation) significantly increased when compared with preoperative ones ( P<0.05). X-ray films showed that the CCD was 8.4 (7.3, 9.4) and 9.2 (8.1, 10.1) mm at 3 days and 12 months after operation, respectively, with a significant difference ( Z=-4.665, P<0.001). During follow-up, there was no complication such as infection, titanium plate entrapment, fracture, internal fixation failure, or redislocation. Conclusion: The treatment of acute acromioclavicular joint dislocation with TightRope system combined with Locking-Loop biplane anatomical reconstruction has the advantages of small incision, joint reduction under direct vision, high fixation strength, and low incidence of postoperative complications, which can effectively relieve the pain of patients' shoulder joint and facilitate the recovery of shoulder joint function.

Mini-open vs. arthroscopic double tight-rope reconstruction after acute AC-joint dislocation: a comparison in functional outcome and sports activity.

INTRODUCTION: In athletes, acromioclavicular joint disruptions account for up to 50% of all shoulder injuries. In high-grade injuries, surgery is favored to ensure a correct restoration of the joint, especially in young athletes. The aim of this study was to compare the clinical, radiological and sport related outcomes of the arthroscopic stabilization with the fixation of the AC joint in a mini-open approach. MATERIALS AND METHODS: 19 patients treated arthroscopically (ASK) and 26 patients with an acute AC-joint dislocation Rockwood V who had undergone the mini-open (MO) surgery were included. Constant Murley Score (CMS), Taft Score (TS) and the Simple Shoulder Tests (SST) were evaluated. The sports activity level was determined according to Valderrabano and the athlete's recovery of their athletic activity level after surgery according to Rhee. Furthermore, all available X-ray images were analyzed. RESULTS: Patients in the ASK group achieved an average score of 11.7 ± 0.6 points in the SST, 10.3 ± 1.8 points in the TS and 91.2 ± 11.8 points in the CMS. On average, patients in the MO group achieved results of 10.5 ± 1.4 points in the SST, 11.7 ± 0.7 points in the TS and 91.6 ± 9.8 points in the CMS. The ASK group showed significant difference regarding the CC distance in side comparison (Δ = 3.6 mm), whereas no significant difference was found in the MO group (Δ = 0.8 mm). In comparison of both groups, the posterior as well as the combined translation were significantly greater in the ASK group than in the MO group (posterior: ASK: 24.8 mm, MO: 19.3 mm, combined: ASK: 29.1 mm, MO: 20.9 mm). Residual horizontal instability was greater in the ASK group (43%) than in the MO group (32%). Similar results were achieved in sports activity and the recovery of athletic activity (Valderrabano: ASK: 2.8, MO: 2.6; Rhee: ASK: 1.6, MO: 1.5). CONCLUSIONS: Both techniques prove to be effective for the stabilization of high-grade AC-joint disruptions in athletes and showed excellent clinical results. From a radiographic standpoint, the mini-open procedure appears superior to the arthroscopic technique. After mini-open surgery postoperative loss of correction is less common and greater horizontal stability is achieved. The results also suggest the mini-open technique is superior to the arthroscopic procedure when aiming to restore the athlete's original level of sports activity.

Suture button placed beneath plate fixation for complex distal clavicle fractures and acromioclavicular joint injuries: a technical note.

Patients with complex distal clavicle and acromioclavicular (AC) joint injuries are at risk of loss of reduction, especially when plates are removed postoperatively. The purpose is to review the authors' preferred technique for treatment of distal clavicle and AC joint injuries utilizing combined suture button and plate fixation, aiming to optimize biomechanical strength of fixation and limit loss of reduction after implant removal. Pre-contoured locking plates or hook plates were utilized atop suture buttons to maintain reduction and optimize biomechanical strength. At final follow-up over one year after plate removal and suture button retention in thirteen patients, reduction was maintained to coracoclavicular interval 1.5 ± 1.4 mm less than contralaterally. DASH scores at final follow-up averaged 5.7 ± 2.5 (range: 3.3 - 11.7). Placing suture button fixation prior to and beneath plate fixation in complex AC joint injuries and distal clavicle fractures allows for maintained fixation and prevents loss of reduction after plate removal.

Risk factors of loss of reduction after acromioclavicular joint dislocation treated with a hook plate.

BACKGROUND: Acromioclavicular joint fixation using a hook plate is effective for the treatment of acute acromioclavicular joint dislocation. However, several studies have reported some complications including loss of reduction after surgery for acromioclavicular joint dislocation. This study aimed to identify the risk factors associated with the loss of reduction after acromioclavicular joint dislocation surgery using a hook plate. METHODS: This was a retrospective study that assessed 118 patients with acromioclavicular joint dislocation, who were diagnosed between March 2013 and January 2019 and underwent surgical treatment using the hook plate (reduction loss group: n = 38; maintenance group: n = 80). The mean follow-up period was 29.9 months (range, 24-40 months). We assessed the range of motion, the American Shoulder and Elbow Surgeons score (ASES), visual analog scale score for pain, and a subjective shoulder value. Radiological assessment of coracoid clavicular distance was performed. The risk factors of reduction loss were analyzed using multivariable logistic regression analysis. RESULTS: Age (p = 0.049), sex (female, p = 0.03, odds ratio OR = 4.81), Rockwood type V (p = 0.049, OR = 2.20), and time from injury to surgery > 7 days (p = 0.018, OR = 2.59) were statistically significant factors in the reduction loss group. There were no significant differences in the clinical outcomes for range of motion, ASES, subjective shoulder value, and visual analog scale scores between the two groups. In the radiological results, preoperative coracoid clavicular distance (p = 0.039) and ratio (p = 0.001), and over-reduction (p = 0.023, OR = 0.40) were significantly different between the two groups. The multivariate logistic regression analysis identified the female sex (p = 0.037, OR = 5.88), a time from injury to surgery > 7 days (p = 0.019, OR = 3.36), and the preoperative coracoid clavicular displacement ratio of the injured shoulder (p < 0.001, OR = 1.03) as risk factors associated with reduction loss following surgery using a hook plate for acromioclavicular dislocation. CONCLUSION: A delayed timing of surgery > 7 days, preoperative coracoid clavicular displacement ratio of the injured shoulder, and female sex were identified as risk factors for loss of reduction after surgery using a hook plate for acromioclavicular joint dislocation. LEVEL OF EVIDENCE: Level IV; retrospective comparison; treatment study.

Acromioclavicular joint injuries at a Colorado ski resort.

BACKGROUND: Acromioclavicular joint (ACJ) injuries are among the most common injuries in contact and non-contact sports. As winter sports become more popular, there has been an increase in shoulder injuries among recreational skiers and snowboarders. METHODS: This was a retrospective analysis of all patients who presented to the Denver Health Winter Park Medical Center with ACJ injury from 2012 to 2017. We examined the incidence of ACJ injuries, the injury mechanism, demographics, and type of ACJ injuries among skiers and snowboarders treated at the clinic. RESULTS: A total of 341 ACJ injuries (6.7% of total visits) were encountered during the study period. The majority of ACJ injures were type I (41.3%) and mainly occurred in men (86.5%). Most (96.8%) of the cases were primary ACJ injuries on the right shoulder (56.9%). The average age of patients with ACJ injuries was 30.0 years (range 10-72). More than half (62.2%) of ACJ injuries occurred while snowboarding. The most common mechanism of injury (93.5%) was fall to the snow while skiing/snowboarding. Women were more likely to have a type I ACJ injury than men (80.4% vs 35.4%; P < 0.001). Women with ACJ injuries were more likely to suffer the injury while skiing than snowboarding (71.7% vs 28.3%; P < 0.001), compared to men who were more likely to suffer the injury while snowboarding than skiing (67.5% vs 32.5%; P < 0.001). CONCLUSIONS: Most of the ACJ injuries were type I and occurred mostly in men. Snowboarders were more likely to have an ACJ injury than skiers. LEVEL OF EVIDENCE: Level IV, Epidemeiology Study.

Minimally invasive reconstruction of acute acromioclavicular joint injuries using the TwinBridge button system.

INTRODUCTION: Acute acromioclavicular joint (ACJ) injuries are among the most common shoulder injuries in active young adults. The most frequently used surgical treatments include the hook plate implantation and arthroscopic treatment using flip-button systems. The aim of this study was to evaluate the results of treating acute ACJ injuries using a new minimally invasive implant based on a flip-button system. MATERIAL AND METHODS: From January 2016 to October 2019, a total of 20 patients with acute ACJ injuries (1 × Type III, 3 × Type IV, 16 × Type V) underwent surgery using the Twinbridge implant (Smith & Nephew). It is a prefabricated construct consisting of two Endobuttons connected with an UltraTape. One button is placed under the coracoid using a special aiming device and two buttons are placed on the clavicle. Preoperatively, 1 day postoperatively, 3 months and at least 1 year postoperatively, patients were clinically examined and bilateral stress view and axial radiographs were obtained. At final follow-up, the simple shoulder test (SST), Taft score, Constant score, and ACJ instability (ACJI) score were recorded and a side-to-side ratio of the coracoclavicular (CC) distance was calculated. RESULTS: All 20 patients were contacted at final follow-up at a mean of 28 (min. 13, max 50) months. Six patients were not willing to come for a clinical and radiographic examination and were contacted via telephone. All six patients were free of complaints. Another two patients free of complaints refused radiographs at final follow-up. The patients presented a mean SST of 99.6% (20 patients, min. 91.7, max. 100), Taft score of 11.6/12 points (12 patients, min. 10, max. 12), ACJI of 85.5/90 points (12 patients, min. 78, max. 90), and a Constant score of 97.1 (14 patients, min. 81.0, max. 100) for the affected shoulder. Preoperative stress view images revealed a mean side-to-side difference of the CC distance with a ratio of 1:2.34 (min. 1:1.80, max. 1:3.33). At final follow-up, CC distance was calculated with a mean ratio of 1:1.12 (min. 1.1, max. 1:1.38). Axial images showed a proper position in all cases. A "perfect" radiological result was achieved in six patients (50%) with a side-to-side CC distance of less than 10% (ratio 1:1.1 or less). A Rockwood type II result was achieved in five patients (42%) with a distance of 10 to 25% (ratio 1.11-1.25). One (8%) presented with a Rockwood type III result with a difference of more than 25% (ratio 1:1.38) and was considered a radiological failure. CONCLUSIONS: When used correctly, the Twinbridge implant offers good-to-excellent clinical and radiographic results using a minimally invasive surgical technique. Complication rate is comparable to other button-systems.

Subject-specific computational modeling of acromioclavicular and coracoclavicular ligaments.

BACKGROUND: Disruption of the acromioclavicular joint is a common injury. Despite the different surgical procedures described for treating this injury, complications such as loss of reduction and failure of fixation remain unacceptably high. We developed a computer model of the acromioclavicular joint to better understand the biomechanical contributions of the ligaments that are typically injured. METHODS: Six fresh frozen human cadaveric shoulders were tested on an AMTI VIVO 6-degree of freedom test platform to measure force-displacement in inferior translation, anteroposterior translation, and internal rotation before and after sequentially transecting the coracoclavicular and acromioclavicular ligaments. These data were used to construct computer models of each specimen. Three-dimensional computed tomographic scans were used to generate a rigid-body dynamics model using the AnyBody Modeling System. The scapula and clavicle were connected by the acromioclavicular joint capsule, the conoid ligament, and the trapezoid ligament. Subject-specific ligament properties were calculated by matching computer predictions to experimental force-displacement data. RESULTS: The calculated free lengths of the conoid, trapezoid, and acromioclavicular ligaments were 13.5 (±3.2), 11.8 (±2.4), and 11.0 (±2.7) mm, respectively. The calculated stiffnesses of the conoid, trapezoid, and acromioclavicular ligaments were 34.3 (±6.3), 28.4 (±3.2), and 33.8 (±8.2) N/mm, respectively. Root mean square deviation (RMSD) of predicted force-displacement curves relative to experimental force-displacement curves (during inferior and anteroposterior translation) was less than 1 mm. For validation of subject-specific models, after ligament properties were calculated, the RMSD of the predicted torque over 15° of internal rotation was 12% of maximum rotational torque (average for 6 specimens). DISCUSSION AND CONCLUSION: Acromioclavicular disruption results in multidirectional instability, which requires careful consideration of the individual contributions of the injured ligaments. In addition, variations in patient anatomy can significantly affect the biomechanical stability of the reconstruction. Subject-specific models can enhance our understanding of the individual and collective biomechanical contributions of the injured soft tissues to the multiaxial stability of the acromioclavicular joint. These models may also be useful for analyzing and assessing biomechanical stability after various types of surgical reconstruction.

Superior clinical results for early arthroscopic treatment of grade IIIb and V acromioclavicular joint instability compared to delayed operative treatment.

BACKGROUND: Arthroscopy-assisted cortical fixation devices have been increasingly used in the operative management of both acute and chronic cases of acromioclavicular joint instability (ACJI). It has been hypothesized that delayed surgical management leads to inferior clinical and radiologic outcomes compared to acute treatment. The purpose of this study is to compare clinical and radiologic outcomes, scapula dyskinesia, and failure or revision rates of arthroscopically treated acute and chronic ACJI. METHODS: This retrospective study of prospectively collected data included all surgically treated patients with grade IIIb and V chronic ACJI between 2013 and 2017, matched 1:1 to a group of acute grade IIIb and V ACJI patients treated during the same time period. Chronic ACJI was defined as delayed surgical treatment >21 days after injury. Chronic cases received an additional hamstring autograft next to the suture pulley systems. Follow-up was obtained at an average of 3.2 years (range: 1.4-6.2). Clinical outcome scores included the Constant-Murley Score (CMS), Taft Score (TF), Nottingham Clavicle Score (NCS), ACJI Score, Sick Scapula Score (SSS), Subjective Shoulder Value (SSV), Subjective Shoulder Test (SST), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, and the visual analog scale pain score. Radiologic follow-up was obtained pre- and postoperatively and at final follow-up. The 2-year results were compared to the results of a 1:1 matched-pair group comprising patients who were treated with an acute ACJI during the same period. RESULTS: Thirty-three (80.5%) of 41 chronic ACJI cases were available for follow-up and were compared with 33 matched-pair cases of acute ACJI (of 41). The clinical scores were significantly better in the acute cohort for the CMS (92 ± 8 vs. 88 ± 8, P = .030), ASES (91 ± 13 vs. 85 ± 13, P = .002), SSS (1.4 ± 1.6 vs. 3.4 ± 2.5, P = .0004), NCS (86 ± 13 vs. 81 ± 13, P = .049), TF (9.9 ± 1.9 vs. 9.0 ± 2.1, P = .030), and ACJI (83 ± 13 vs. 75 ± 1, P = .003). In contrast to the chronic cohort, the acute cohort illustrated a significant loss of reduction at follow-up (P = .020). CONCLUSION: Based on the results of this study, early arthroscopy-assisted operative treatment of grade IIIb and V ACJIs seems superior to delayed surgical intervention of grade IIIb and V ACJIs. Furthermore, an additional autograft loop leads to less loss of reduction compared with suture pulley/suspensory loop fixation standalones.