[A man with swelling of the shoulder]. / Een man met een zwelling van de schouder.

A 64-year-old male with a history of gout was seen with a swelling of het left acromioclavicular joint. Microscopic examination revealed monosodium urate crystals, confirming the diagnosis of tophaceous gout.

Management of type III acromioclavicular joint dislocation: A Delphi consensus survey by Shoulder & Elbow Society, India (SESI).

PURPOSE: The study aimed to report the results of the Delphi survey conducted by the Shoulder, Elbow Society India (SESI), to achieve consensus on ambiguous topics in managing type III acromioclavicular joint (ACJ) dislocations. METHODS: This study was based on responses from the Shoulder Elbow Society India (SESI) panel of peer-selected twenty senior surgeons practicing shoulder orthopedics. They participated in two rounds of the survey to obtain consensus on several topics pertaining to the management of type III ACJ dislocations. Consensus was achieved when at least 70 % of the panel members selected at least a 4-point on a 5-point Likert scale. RESULTS: Our Delphi survey reached a consensus on seven topics of ambiguity. An anteroposterior and axillary view of the shoulder without any traction or weight in hand is sufficient in the setting of a suspected type III ACJ dislocation. Magnetic resonance imaging (MRI) is not routinely indicated in type III ACJ dislocation. Either cross-arm adduction X-rays or clinical examination may be used to distinguish between ISAKOS (International Society of Arthroscopy, Knee surgery and Orthopaedics Sports medicine) IIIA and B classification of ACJ to identify stable and unstable injuries. Conservative treatment can be offered to patients who have stable injuries and who are not high-demand individuals in acute type III ACJ dislocations. In conservative management of type III ACJ dislocation, a two-week sling suffices. Jones strapping has no clear advantage over a shoulder sling. Coracoclavicular reconstruction with an autograft is an acceptable way to treat symptomatic, chronic grade III ACJ dislocation. CONCLUSION: The survey helped achieve consensus on several controversial issues related to type III ACJ dislocations. However, there remains ambiguity on the definition of chronicity of such dislocations, the necessity of bilateral Zanca views, and the duration of conservative trial before switching to a surgical line of management.

Post-traumatic Coracoclavicular Ligament Ossification: A Case Report and Surgical Technique.

CASE: A patient presented with complete coracoclavicular ligament ossification after an unnoticed acromioclavicular joint Rockwood Type IV dislocation. He had full passive range of motion in the glenohumeral joint but was disabled by a loss of both active (80°) and passive (90°) abduction due to insufficient passive scapulo-thoracic motion. He was treated with an arthroscopic osteotomy of the coracoclavicular ligament ossification. CONCLUSION: One year after the surgery, active abduction was improved by 45° (80°-125°) with no recurrence of the ossification on the radiographs. Arthroscopic osteotomy of complete coracoclavicular ligament ossification seems effective in restoring abduction in these patients. LEVEL OF EVIDENCE: IV.

Acromioclavicular joint dislocation with loop double endobutton fixation assisted by orthopaedic surgery robot positioning system.

OBJECTIVE: Acute acromioclavicular (AC) joint dislocation is a common orthopedic injury that can significantly impair shoulder function and reduce quality of life. Effective treatment methods are essential to restore function and alleviate pain. To investigate the short-term clinical efficacy of the minimally invasive closed-loop double endobutton fixation assisted by orthopaedic surgery robot positioning system (TiRobot) in the treatment of AC joint dislocation, and to evaluate its feasibility and safety. METHODS: The clinical data of 19 patients with AC joint dislocation who underwent treatment with closed-loop double Endobutton fixation assisted by TiRobot between May 2020 and December 2022 were retrospectively analyzed. Visual Analog Scale (VAS) pain scores, the Constant Murley Score (CMS), and shoulder abduction range of motion were assessed and compared preoperatively and at the last follow-up. Computed tomography (CT) parameters of the acromioclavicular joint, including acromioclavicular distance (ACD), the distance between the upper and lower Endobutton (DED), the horizontal distance between the anterior edge of the distal clavicle and the anterior edge of the acromion (DACC), the diameter of the clavicular tunnel (DCT), and coracoid tunnel diameter (DC), were compared at 2 days, and 1 month after surgery, as well as at the last follow-up, along with the evaluation of intraoperative and postoperative complications. RESULTS: The postoperative VAS, CMS, and shoulder-abduction range of motion were significantly improved compared with the preoperative (all, P<0.05). The statistical analysis showed no significant difference in the CT image parameters of the acromioclavicular joint at 2 days and 1 month after surgery(all, P>0.05). Comparisons of DCT and DC revealed statistically significant differences between the last follow-up and 1 month after surgery (P<0.05), and no statistically significant difference was found in ACD, DED, and DACC(all, P>0.05). There were no complications such as infection or vascular or neurological damage, no cases of rostral or clavicle fractures, loss of reduction, heterotopic ossification, shoulder stiffness, and no loosening or breaking of internal fixations. CONCLUSION: Closed-loop double endobutton internal fixation assisted by TiRobot is an ideal method for the treatment of acute acromioclavicular (AC) joint dislocation. This method has the advantages of relatively simple operation, more accurate localization of bone tunnel during operation, less surgical trauma, and good recovery of shoulder function.

[Single mini-incision combined with honeycomb titanium plate in treatment of acute acromioclavicular joint dislocation].

OBJECTIVE: To explore clinical effect of single small incision with honeycomb titanium plate in treating acute acromioclavicular dislocation. METHODS: The clinical data of 40 patients with acute acromioclavicular dislocation admitted from December 2019 to December 2021 were retrospectively analyzed and divided into two groups according to different surgical methods. Among them, 20 patients were fixed with single small incision with honeycomb titanium plate (titanium plate group), including 11 males and 9 females, aged from 23 to 65 years old with an average of (47.40±12.58) years old;12 patients on the left side, 8 patients on the right side;11 patients with type Ⅲ, 3 patients with type Ⅳ, and 6 patients with type Ⅴ according to Rockwood classification. Twenty patients were fixed with clavicular hook plate (clavicular hook group), including 8 males and 12 females, aged from 24 to 65 years old with an average of (48.40±12.08) years old;12 patients on the left side, 8 patients on the right side;10 patients with type Ⅲ, 2 patients with type Ⅳ, and 8 patients with type Ⅴ according to Rockwood classification. Operative time, incision length, intraoperative blood loss, hospital stay, visual analogue scale (VAS) and Constant-Murley score of shoulder joint function were compared between two groups. Anteroposterior radiographs of the affected shoulder joint were recorded before, immediately and 6 months after surgery, and the coracoclavicular distance was measured and compared. RESULTS: Both groups of patients were successfully completed operation without serious complications. All patients were followed up for 6 to 15 months with an average of (11.9±4.8) months. There were no incisional infection, internal plant fracture or failure, bone tunnel fracture and other complications occurred. The incision length of titanium plate group (35.90±3.14) mm was significantly shorter than that of clavicular hook group (49.30±3.79) mm (P<0.05). There were no significant difference in operative time, intraoperative blood loss and hospital stay between two groups (P>0.05). At 1 and 3 months after operation, VAS of titanium plate group was lower than that of clavicular hook group (P<0.05). Connstant-Murley scores in titanium plate group at 1, 3 and 6 months after operation were (86.80±1.36), (91.60±2.32) and (94.90±2.22), respectively;and in clavicular hook group were (78.45±5.47), (85.55±2.01) and (90.25±1.92), which were higher than that of clavicular hook group (P<0.05). There was no significant difference in coracoclavicular distance between two groups immediately and 6 months after operation(P>0.05). CONCLUSION: For the treatment of acute acromioclavicular joint dislocation, single small incision combined with honeycomb titanium plate have advantages of shorter incision, fast recovery of shoulder joint function without the second operation, and has good satisfaction of patient.

Patient-reported, clinical and radiological factors associated with the result after non-surgical management of acute AC joint dislocation Rockwood type III and V.

PURPOSE: The treatment of Rockwood type III and V acromioclavicular (AC) joint dislocations is controversial, and an individualized treatment algorithm is yet to be developed. The objective of this study was to investigate the association of demographical, clinical, patient-reported and radiological variables with the Western Ontario Shoulder Instability Index (WOSI) score and risk of surgery. METHODS: Inclusion criteria for this prospective cohort study were patients aged 18-60 with an acute AC joint dislocation with >25% increase in the coracoclavicular distance on bilateral Zanca radiographs. Patients were treated non-surgically with 3 months of home-based training and the option of delayed surgical intervention. The outcomes were the WOSI score and surgery yes/no. Demographical, clinical, patient-reported (WOSI and Shoulder Pain and Disability Index [SPADI]) and radiological variables were collected at baseline and 6 weeks after the injury and investigated for association with the outcomes at 3 months, 6 months and 1 year. RESULTS: Ninety-five patients with Rockwood type III/V AC joint dislocation were included. Pre-injury participation in overhead/collision sports was a risk factor for surgery with an odds ratio of 5 (p = 0.03). Reduced range of motion (ROM) at baseline was associated with reduced WOSI scores and increased risk of surgery. At 6 weeks, reduced ROM, increased SPADI and increased pain during cross-over were associated with the outcomes. Radiological measurements were not correlated with the result. At the 6 weeks follow-up, patients eventually requiring surgery could be detected with a sensitivity of 100% and a specificity of 94% based on a SPADI score of >30 and a ROM ≤ 140° in shoulder flexion or abduction. CONCLUSION: ROM was the only variable consistently associated with both WOSI and risk of surgery. Six weeks after the injury, it was possible to detect patients in need of surgery based on ROM and SPADI with a sensitivity of 100% and a specificity of 94%. LEVEL OF EVIDENCE: Level II.

The ISAKOS subclassification of Rockwood type III AC joint dislocations in a stable type A and an unstable type B is not clinically relevant.

PURPOSE: The treatment of Rockwood type III AC joint dislocations has been debated for decades. In 2014, the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) Upper Extremity Committee suggested a subclassification of the injury into type A, considered stable and best treated nonsurgically, and type B, considered unstable and best treated surgically. Type B is defined by the presence of scapular dyskinesis and overriding of the clavicle to the acromion on a modified lateral radiograph. The objective of the study was to investigate if this subclassification is clinically relevant. METHODS: This was a prospective cohort study. Inclusion criteria were patients aged 18-60 years with acute AC joint dislocation and a baseline Zanca radiograph with an increase in the CC distance of >25% compared to the uninjured side. All patients were treated nonsurgically with 3 months of home-based training and with the option of delayed surgical intervention. Patients were assessed at baseline and at follow-ups 6 weeks, 3 months, 6 months and 1 year after the injury. At the 6-week follow-up, patients were graded as stable and unstable according to the ISAKOS criteria. Outcomes were the Western Ontario Shoulder Instability Index (WOSI) and referral for surgery. RESULTS: At 6 weeks of follow-up, 20 patients were classified as stable type A and 69 were classified as unstable type B. The ISAKOS subclassification was not clinically relevant, but patients graded as stable had statistically significantly better WOSI scores at 6 months compared to the unstable group (p = 0.03) but not at 3 months or 1 year. Nine patients (9.5%), all from the unstable group, were referred for surgery. No patients from the stable group underwent surgery (n.s). CONCLUSION: The ISAKOS subclassification of Rockwood type III in a stable type A and an unstable type B is not clinically applicable. LEVEL OF EVIDENCE: Level II.

The Effect of Clavicular Tunnel Position on Reduction Loss in Patients with Acute Acromioclavicular Joint Dislocations Operated with a Single-Bundle Suspensory Loop Device.

OBJECTIVE: The treatment of acromioclavicular joint (ACJ) dislocations offers numerous options, and ongoing debates persist regarding their comparative effectiveness. Among these options, the suspensory loop device (SLD) is one of the most favored treatment modalities. Despite the observed high reduction loss rate associated with SLD, the treatment yields favorable clinical outcomes. This study aimed to investigate the clinical outcomes of patients with acute type 3 and 5 ACJ dislocations who underwent open and arthroscopic procedures using a single-bundle SLD, and to evaluate the effect of clavicular tunnel position on reduction loss. METHODS: Thirty-seven eligible patients diagnosed with acute type 3 and type 5 ACJ dislocation who underwent open and arthroscopic surgery with a single-bundle SLD between January 2015 and March 2022 were evaluated retrospectively. Demographic data and radiological measurements including coracoclavicular (CC) interval, clavicle length (CL), and implant distance (ID) were recorded. The ID/CL ratio was calculated and a value between 0.17 and 0.24 was considered as "acceptable implant position". Reduction loss and other complications were noted. Patients were divided into two groups: open (Group 1) and arthroscopic (Group 2). Constant Murray Score (CMS) and Visual Analog Scale (VAS) were used for clinical and functional outcomes. Non-parametric tests were used for statistical analysis of variables. RESULTS: The study included six females (16.2%) and 31 males (83.8%) with a mean age of 40.2 ± 14.7 years (range: 20-75). The mean follow-up period was 22.3 ± 16.7 months (range: 6-72). The average time from trauma to surgery was 6.3 ± 5.3 days (range: 1-18). At the last follow-up, the CMS was 89.3 ± 8.8 and the VAS score was 2.1 ± 0.9. The mean ID/CL ratio was 0.19 ± 0.1 and 19 patients (51.4%) were between 0.17 and 0.24. Reduction loss was observed in nine patients (24.3%). There were no significant differences between Group 1 and Group 2 regarding operation time (p = 0.998), ID/CL ratio (p = 0.442), reduction loss (p = 0.458), CMS (p = 0.325), and VAS score (p = 0.699). Of the 28 patients without reduction loss, 16 had an ID/CL ratio between 0.17 and 0.24 (p = 0.43). Furthermore, within the 0.17-0.24 interval, CMS was higher with an average of 91.8 ± 5.1 compared to the other intervals (p = 0.559). CONCLUSION: The clinical and functional outcomes of acute type 3 and type 5 ACJ dislocation operated open and arthroscopically with single-bundle SLD are similar and satisfactory. A clavicular tunnel position in the range of 0.17-0.24 (ID/CL ratio) is recommended to maintain postoperative reduction.

Stress fracture of the clavicle associated with sternocostoclavicular hyperostosis combined with bony ankylosis of the acromioclavicular joint and ossification of the coracoclavicular ligament.

Sternocostoclavicular hyperostosis (SCCH) has been reported in patients with pustulotic arthro-osteitis, but there are few reports of marked ossification of the lateral part of the clavicle. Here, we report a case of stress fracture in a patient with SCCH with marked ossification of the lateral part of the clavicle. In this case, the clavicular fracture was proximal and no dislocation. Conservative treatment with a clavicle band and the administration of corticosteroids resulted in rapid symptom improvement. Eight months later, the patient had no difficulty in daily life, but X-rays showed that bone fusion was not complete. Therefore, it is necessary to carefully follow-up such patients for any recurrence of symptoms and radiographic changes.

Clavicular tunnel widening after acromioclavicular joint reconstruction: comparison between single and double clavicular tunnel techniques.

Acromioclavicular joint (ACJ) reconstruction using artificial ligaments is a common surgical treatment for Rockwood grade III or higher injuries. These techniques use bone tunnels in the clavicle and coracoid to insert the Tightrope implants. This multicenter retrospective study compares long term radiographic follow up of clavicular tunnel widening in two groups of patients with high-grade ACJ injury who underwent reconstruction using two different surgical techniques. The first group of 23 patients underwent an arthroscopic single clavicular tunnel ACJ reconstruction. The second group of 23 patiënts underwent an open double clavicular tunnel reconstruction. Inclusion criteria are Rockwood grade III or higher injury and minimum 18 months of follow-up. Exclusion criteria are distal clavicle fracture and additional stabilization techniques. Radiographic results were measured on anteroposterior shoulder radiographs taken at the first and last follow-up. Clavicular tunnel widening is the main outcome measurement. Secondary outcomes are heterotopic ligament calcifications, migration of buttons, tunnel fracture and loss of acromioclavicular reduction. The mean clavicular tunnel widening in the single clavicular tunnel technique is 1.91 mm. In the double clavicular tunnel technique, the widening of the medial tunnel is 2.52 mm and 3.59 mm in the lateral tunnel. The difference in widening between the single tunnel and the lateral tunnel is significant (p=0.003). A very clear observation on all follow-up X-rays was a reorientation of the clavicular tunnels towards the coracoid. The double clavicular tunnel technique has more tunnel widening in both tunnels compared to the single bundle technique.

[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.

Surgical treatment of acromioclavicular joint dislocation of Rockwood III/IV: a retrospective study on clavicular hook plate versus arthroscopic TightRope loop titanium button.

PURPOSE: To compare the clinical efficacy of arthroscopic TightRope loop titanium button and clavicular hook plate in the treatment of acromioclavicular joint (ACJ) dislocation of Rockwood III/IV. METHODS: A retrospective analysis of patients with ACJ dislocation in our hospital from January 2018 to December 2020 was conducted. The patients were assigned to be treated with arthroscopic TightRope loop titanium button (TR group) or clavicular hook plate (HP group). The preoperative, intraoperative and postoperative data and imaging findings of the two groups were compared. RESULTS: A total of 58 eligible patients were enrolled in this study. Compared with HP group, TR group had shorter incision length and less blood loss during operation. Postoperative follow-up ranged from 12 to 24 months (mean 15.4 months). At 6 months and 12months postoperatively, compared with HP group, TR group had lower VAS and higher CMS, and the difference was statistically significant. At 12 months postoperatively, compared with HP group, TR group had lower ACJ gap and coracoclavicular joint(CCJ) distance, and the difference was statistically significant.In HP group, there were 3 cases of subacromial impact, 1 case of redislocation, 2 cases of traumatic arthritis and 2 cases of wound infection. There was 1 case of redislocation in TR group. CONCLUSIONS: Compared with clavicular hook plate, arthroscopic TightRope loop titanium button is minimally invasive, safe and effective in the treatment of ACJ dislocation, and has a good trend in clinical application.

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 .

Acromioclavicular joint dislocation Rockwood type III and V show no difference in functional outcome and 91% recovered well without the need for surgery.

PURPOSE: Acromioclavicular (AC) joint dislocations are common injuries, but the indication for and timing of surgery is debated. The objective of the study was to evaluate the results after acute AC joint dislocations Rockwood type III and V treated nonsurgically with the option of delayed surgical intervention. METHODS: This is a prospective cohort study with clinical, radiological and patient-reported outcome assessment at baseline, 6 weeks, 3 months, 6 months and 1 year after acute AC joint dislocation. Patients aged 18-60 with acute AC joint dislocation and a baseline panorama (Zanca) radiograph with an increase in the coracoclavicular distance of >25% compared to the uninjured side were eligible for inclusion. All patients were treated nonsurgically with 3 months of home-based training and with the option of delayed surgical intervention. The primary outcome was the Western Ontario Shoulder Instability Index (WOSI). Secondary outcomes were surgery yes/no and the Shoulder Pain and Disability Index (SPADI). RESULTS: Ninety-five patients were included. Fifty-seven patients were Rockwood type III and 38 patients were type V. There were no statistically significant differences in WOSI and SPADI between patients with type III and V injuries at any time point. Nine patients (9.5%) were referred for surgery; seven type III and two type V (ns). CONCLUSION: Ninety-one percent of patients with acute AC joint dislocation Rockwood type III and V recovered without surgery and there were no differences in outcome scores between type III and V at any time point. LEVEL OF EVIDENCE: Level IV.

Arthroscopic distal clavicle resection versus conservation in patients with combined rotator cuff tears and acromioclavicular joint osteoarthritis.

PURPOSE: The most common cause of shoulder pain originating from the acromioclavicular (AC) joint is osteoarthritis, causing pain and disability. Operative Management of AC arthritis includes arthroscopic distal clavicle resection (DCR) and open clavicle resection. This study was conducted to evaluate the outcomes of isolated rotator cuff repair with conservative treatment of ACJ arthritis versus the combined resection of the distal clavicle with the repair of a rotator cuff tear, in cases with acromioclavicular arthritis. METHODS: A total of 46 patients with unilateral or bilateral combined rotator cuff tear and acromioclavicular arthritis were included, they were classified into 2 independent groups: Conservative group (23 patients), and DCR group (23 patients). All patients were subjected to full history taking, examination, pre and post-operative University of California at Los Angeles shoulder scoring scale (UCLA), Antero-Posterior and Zanca X-rays views, early and late complications. RESULTS: Mean age was (51 ± 9) years, males were predominant (56.5%). The average post-operative UCLA score was (31.1 ± 4.9), and the average time to return to work was (214 ± 22). (2.2%) of patients had early complications, (19.6%) had late complications, (32.6%) had > 24 h till 1st post-operative analgesia, and (87%) needed MgSO4 Injection. We found a highly significant increase in UCLA score measurements in the Conservative group, and a highly significant increase in UCLA score measurements in the DCR group (p < 0.01). But there was no difference between the 2 groups. CONCLUSION: Conventional conservative approach with arthroscopic rotator cuff repair and subacromial decompression has proven to be as effective as arthroscopic rotator cuff repair and subacromial decompression with DCR, in terms of efficacy and safety profiles in short term, but with more risks of potential hazards and cost with the DCR.

In Vivo Analysis of Acromioclavicular Kinematics and Distance During Multiplanar Humeral Elevation.

BACKGROUND: Knowledge of acromioclavicular (AC) joint kinematics and distance may provide insight into the biomechanical function and development of new treatment methods. However, accurate data on in vivo AC kinematics and distance between the clavicle and acromion remain unknown. PURPOSE/HYPOTHESIS: The purpose of this study was to investigate 3-dimensional AC kinematics and distance during arm elevation in abduction, scaption, and forward flexion in a healthy population. It was hypothesized that AC kinematics and distance would vary with the elevation angle and plane of the arm. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 19 shoulders of healthy participants were enrolled. AC kinematics and distance were investigated with a combined dual fluoroscopic imaging system and computed tomography. Rotation and translation of the AC joint were calculated. The AC distance was measured as the minimum distance between the medial border of the acromion and the articular surface of the distal clavicle (ASDC). The minimum distance point (MDP) ratio was defined as the length between the MDP and the posterior edge of the ASDC divided by the anterior-posterior length of the ASDC. AC kinematics and distance between different elevation planes and angles were compared. RESULTS: Progressive internal rotation, upward rotation, and posterior tilt of the AC joint were observed in all elevation planes. The scapula rotated more upward relative to the clavicle in abduction than in scaption (P = .002) and flexion (P = .005). The arm elevation angle significantly affected translation of the AC joint. The acromion translated more laterally and more posteriorly in scaption than in abduction (P < .001). The AC distance decreased from the initial position to 75° in all planes and was significantly greater in flexion (P < .001). The MDP ratio significantly increased with the elevation angle (P < .001). CONCLUSION: Progressive rotation and significant translation of the AC joint were observed in different elevation planes. The AC distance decreased with the elevation angle from the initial position to 75°. The minimum distance between the ASDC and the medial border of the acromion moved anteriorly as the shoulder elevation angle increased. CLINICAL RELEVANCE: These results could serve as benchmark data for future studies aiming to improve the surgical treatment of AC joint abnormalities to restore optimal function.

A Self-Designed Endobutton Installation Device for Coracoclavicular Stabilization in Acute Rockwood Type III Acromioclavicular Joint Dislocation.

OBJECTIVE: Endobutton technique could provide flexible coracoclavicular (CC) stabilization for acromioclavicular joint (ACJ) dislocation and achieved good clinical outcomes. However, the difficult part of this technique was placement of the Endobutton to the coracoid base. In this study, we designed an Endobutton installation device to place the Endobutton at the coracoid base. And we examined the clinical and radiographic outcomes of patients with acute Rockwood type III ACJ dislocation repaired with Endobutton using this device. METHODS: We designed an Endobutton installation device to place the Endobutton at the coracoid base to achieve CC stabilization. We retrospectively reviewed 42 patients with acute Rockwood type III ACJ dislocation who underwent CC stabilization with Endobuttons placed either using this novel device (group I, n = 19) or the traditional technique (CC stabilization without using special device, group II, n = 23) from January 2015 to April 2020. The two groups were compared regarding the operative time, intraoperative blood loss, and clinical and radiologic outcomes at final follow-up. The operation-related complications were also evaluated. The Student's t test and the Mann-Whitney U-test were used to compare differences in continuous variables. Differences in categorical variables were assessed with either the Pearson's chi-squared test or Fisher's exact test. RESULTS: Forty-two patients were clinically followed up for a minimum of 12 months. Compared with group II, group I had a significantly shorter mean operative time (56.05 ± 7.82 min vs. 65.87 ± 7.43 min, p < 0.01) and significantly lesser mean intraoperative blood loss (67.89 ± 14.75 mL vs. 94.78 ± 25.01 mL, p < 0.01). At final follow-up, there were no significant differences between the two groups in the visual analog scale score for pain, Oxford Shoulder Score, Disabilities of the Arm, Shoulder, and Hand score, and postoperative CC distance of the affected side. Loss of reduction occurred in four patients in group I and three patients in group II (p = 0.68); there were no other operation-related complications in either group. CONCLUSIONS: The Endobutton installation device makes placement of the Endobutton at the coracoid base easier and achieves satisfactory clinical and radiologic outcomes without additional complications in acute Rockwood type III ACJ dislocation.

Shoulder injuries in Brazilian professional football players: epidemiological analysis of 3828 games.

OBJECTIVES: Football is a globally played sport that poses potential risks for musculoskeletal injuries. Upper-limb injuries have a lower incidence rate than lower-limb injuries but can still cause absenteeism and performance impairment in football players. This descriptive epidemiological study aimed to evaluate and compare the epidemiological data on shoulder injuries among professional football players in two major Brazilian football championships. METHODS: Data were collected throughout the championships, and club physicians medically evaluated each player during official games using two online forms. The collected information included the player's age and position, injury diagnosis, laterality, location on the field where the injury occurred, playing time, imaging examinations performed, need for surgical treatment, time to return to play (TRP), and recurrence of the injury. The incidence of injuries was evaluated using the Federation Internationale de Football Association (FIFA) incidence formula. RESULTS: A total of 107 shoulder injuries were recorded (4.3% of all injuries), with a FIFA incidence of 0.847. Glenohumeral dislocations (GHDs) and acromioclavicular dislocations (ACDs) accounted for 37.38% and 35.51% of all shoulder injuries, respectively. Goalkeepers and defenders presented, respectively, a 2.15 and 1.57 times increased risk of suffering shoulder injuries, while attackers presented a 0.63 times decreased risk. Injury recurrence was observed in 14.95% of cases, with GHDs and ACDs showing recurrence rates of 35.00% and 5.26%, respectively. Surgery was performed in 9.35% of cases, with GHDs representing 50% of all surgeries. The average TRP was 22.37 days, with severe and major injuries accounting for 11.21% and 10.28% of all injuries, respectively. Goalkeepers had the highest average TRP of 36.15 days. Recurring injuries had a higher average TRP of 33.44 days compared to nonrecurring injuries, which had an average TRP of 20.43 days. Surgically treated injuries had the highest average TRP of 112.5 days. CONCLUSION: Shoulder injuries in the professional football scenario are of great concern due to the high recurrence rate and need for surgical treatment, which will lead to a long TRP. These findings emphasize the need to implement prevention protocols and effective treatments to reduce the consequences of such injuries, which are usually underestimated in this sport. LEVEL OF EVIDENCE: III.