Clinical effect of modified anterolateral acromioarthroplasty during arthroscopic rotator cuff repair.

BACKGROUND: This study aimed to compare the clinical effect of modified anterolateral and traditional acromioplasty in arthroscopic rotator cuff repair. METHODS: The clinical data of 92 patients with total rotator cuff tears admitted to the Department of Joint Surgery of Jinhua Central Hospital from January 2016 to December 2019 were retrospectively analyzed. Among them, 42 patients underwent traditional acromioplasty during arthroscopic rotator cuff repair, and 50 underwent modified anterolateral acromioplasty. Patients were evaluated for preoperative and postoperative shoulder function, pain and critical shoulder angle, and incidence of rotator cuff re-tear at 12 months postoperatively. RESULTS: The preoperative general data of patients in the classic and modified anterolateral acromioplasty groups did not differ significantly (P > 0.05) and were comparable. The UCLA, ASES, and Constant shoulder joint scores were significantly improved in both groups. The VAS score was significantly decreased at 12 months postoperative than preoperative, with a statistically significant difference (P ≤ 0.05). Shoulder function and pain scores did not differ significantly between the two groups at 12 months postoperatively (P > 0.05). The CSA did not differ significantly between preoperative and postoperative 12 months in the traditional acromioplasty group (P > 0.05). However, 12 months postoperative CSA in the modified anterolateral acromioplasty group was significantly smaller than the preoperative CSA, with a statistically significant difference (P ≤ 0.05). The rates of rotator cuff re-tears were 16.67% (7/42) and 4% (2/50) in the two groups at 12 months postoperatively, respectively, with statistically significant differences (P ≤ 0.05). CONCLUSIONS: Traditional and modified anterolateral acromioplasty while treating total rotator cuff tears using arthroscopic rotator cuff repair significantly improves shoulder joint function. However, modified anterolateral acromioplasty significantly reduced the CSA value and decreased the incidence of rotator cuff re-tears.

Do preoperative scapular fractures affect long-term outcomes after reverse shoulder arthroplasty?

BACKGROUND: Postoperative scapular stress fractures (SSFs) are a formidable problem after reverse shoulder arthroplasty (RSA). Less is known about patients who have these fractures preoperatively. The primary aim of this study was to examine postoperative satisfaction in patients undergoing primary RSA who have preoperative SSF and compared to a matched cohort without preoperative fracture. The secondary aim was to examine the differences in patient-reported outcomes between and within study cohorts. METHODS: A retrospective chart review of primary RSAs performed by a single surgeon from 2000 to 2020 was conducted. Patients diagnosed with cuff tear arthropathy (CTA), massive cuff tear (MCT), or rheumatoid arthritis (RA) were included. Five hundred twenty-five shoulders met inclusion criteria. Fractures identified on preoperative computed tomography scans were divided into 3 groups: (1) os acromiale, (2) multifragments (MFs), and (3) Levy types. Seventy-two shoulders had an occurrence of SSF. The remaining 453 shoulders were separated into a nonfractured cohort. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and visual analog scale (VAS) scores were compared pre- and postoperatively in the total fracture group and the nonfractured group cohort. The multifragment subgroup was also compared to the pooled Os/Levy subgroup. RESULTS: The total incidence of SSF in all shoulders was 13.7%. There was a difference in satisfaction scores at all time points between the nonfracture (7.9 ± 2.8) and total fracture group (5.4 ± 3.6, P < .001, at last visit). There was also a greater ASES total score in the nonfractured group vs the total fracture group at the final visit (69.4 ± 23.4 and 62.1 ± 24.2; P = .02). The MF group had worse ASES functional or VAS functional scores than the Os/Levy group at all time points: at 1 year, ASES function: MF 24.2 ± 14.5 and Os/Levy 30.7 ± 14.2 (P = .045); at 2 years, ASES function: MF 21.4 ± 14.4 and Os/Levy 35.5 ± 10.6 (P < .001); and at last follow-up, VAS function: MF 4.8 ± 2.8 and Os/Levy 6.4 ± 3.2 (P = .023). DISCUSSION: Scapular fractures were proportionally most common in patients diagnosed with CTA (16.3%) compared with a 9.2% and 8.6% incidence in patients diagnosed with MCT and RA, respectively. Patients with preoperative SSF still see an improvement in ASES scores after RSA but do have lower satisfaction scores compared with the nonfractured cohort. The multifragment fracture group has lower functional and satisfaction scores at all postoperative time points compared with both the nonfracture and the Os/Levy fracture group.

Acromion fractures after reverse shoulder arthroplasty occur in predictable clusters.

BACKGROUND: Acromion and scapular spine fractures (ASFs) following reverse total shoulder arthroplasty (RSA) have been reported at a rate of 3.9%. The location of the fracture has been shown to be an important factor in determining the outcomes of nonoperative treatment, with medial fractures having worse outcomes than lateral fractures. As the debate between operative and nonoperative treatment continues, a more precise understanding of the location of the fracture is necessary for effective management. The purpose of this study was to use 3-dimensional computed tomography (CT) reconstruction to characterize the exact location of ASFs after RSA. METHODS: A retrospective review of 2 separate institutional shoulder and elbow repositories was performed. Patients with post-RSA ASFs documented by post-fracture CT scans were included. The query identified 48 patients who sustained postoperative ASFs after RSA between July 2008 and September 2021. CT scans of patients with ASFs were segmented using Mimics software. Eight patients were excluded because of poor image quality. Each bone model was manipulated using 3-Matic Medical software to align the individual scapula with an idealized bone model to create a view of scapular fracture locations on a normalized bone model. This model was used to classify the fractures using the modified Levy classification. RESULTS: The study cohort consisted of 40 patients with a diagnosis of postoperative ASF after RSA. The median age at the time of surgery was 76 years (interquartile range, 73-79 years). The cohort comprised 32 women (80%) and 8 men (20%), with a median body mass index of 27.8. Only 10 patients (25%) had a previous diagnosis of osteoporosis and 6 (13%) had a diagnosis of inflammatory arthritis; 53% of patients underwent RSA owing to rotator cuff tear arthropathy. The distribution of fracture locations was similar within the cohort. However, lateral fractures were slightly more prevalent. The most common fracture location was the type I zone, with 12 fracture lines (29%). There were 11 fracture lines (26%) in the type IIa zone, 10 (23%) in the type IIb zone, 0 in the type IIc zone, and 9 (21%) in the type III zone. CONCLUSION: ASFs after RSA occur in 4 predictable clusters. No fractures appeared to distinctly cluster in the type IIc zone, which may not represent a true fracture zone. Understanding the distribution of these fractures will help to enable the future design of implants and devices to stabilize the fractures that require fixation.

Ipsilateral fractures of the acromion and coracoid processes of the scapula.

A fracture of the acromion and coracoid processes of scapula is rarely seen in the outpatient clinic, due to the acromion's anatomical position and shape, as well as the strong ligaments and muscles that are attached to it. These fractures are caused by either direct or indirect high-energy trauma injuries to the shoulder joint, leading to severe pain and a grossly restricted range of motion. Several acromial classifications were reported, but this type of longitudinal plane fracture of the acromion process in our case is yet to be described in the current literature. We present a rare combination of the coracoid process and unstable acromion bony projection fractures that have not previously been noted for this type of fracture. The closest to this is Kuhn's type III classification. A 51-year-old male presented to our emergency department complaining of the right shoulder pain and difficulty raising his arm following a 2-wheeler accident. The patient was managed by open reduction and internal fixation with 3 cannulated cancellous screws fixation and progressed well with no postoperative complications. He was asymptomatic postoperatively and regained full range of motion after 4 months.

Risk factors and incidence of short-term complications following open reduction and internal fixation of scapula fractures.

PURPOSE: To determine the short-term complication rates following open reduction and internal fixation of scapula fractures, factors affecting the development of adverse events, and complication rates based on the anatomic location of the fracture. METHODS: Thirty-day complication rates for patients who underwent open reduction and internal fixation of the scapula were compared between glenoid, body, coracoid, and acromion fracture locations, as identified by International Classification of Disease codes. Possible adverse events included postoperative surgical site infection, renal insufficiency, intubation, pneumonia, deep vein thrombosis, pulmonary embolism, urinary tract infection, wound dehiscence, stroke, and blood transfusion. RESULTS: A total of 251 scapula fractures were identified, with 161 having known fracture locations: 105 glenoid, 20 body, 9 coracoid, and 27 acromial fractures. The rate of any adverse event for all scapular fractures was 2.0%, with no significant difference between anatomic locations (p = 0.79). The overall rates of transfusion, surgical site infection, and return to OR were 0.4%, 0.8%, and 3.98%. Steroid use associated with a significantly increased risk of any adverse event (OR: 55.57, p = 0.038) and outpatient status demonstrated a protective effect on reoperation (OR: 0.11, p = 0.014). There were no significant differences in the rates between groups [transfusion (p = 0.91); surgical site infection (p = 0.17); reoperation (p = 0.85)]. CONCLUSION: Complication rates within thirty days of ORIF for scapula fracture were low. Reoperation was the most common complication, followed by surgical site infection, wound dehiscence, stroke, transfusion, and pneumonia. Steroid use was a risk factor for developing any adverse event, and outpatient status was protective against reoperation. The 30-day complication profile of glenoid, body, coracoid, and acromial fractures was not significantly different. The low complication rates support the relative short-term safety of operative intervention with internal fixation. LEVEL OF EVIDENCE: Level III.

Physeal injuries of the clavicle: pediatric counterparts to adult acromioclavicular and sternoclavicular joint separations.

The epiphyses at the medial and lateral ends of the clavicle are small, ossify relatively late, and may not fuse until early adulthood. Because of this unique anatomy, pediatric and young adult injuries that involve the clavicle often differ from the patterns typically seen in older adults. Clavicular trauma that affects the acromioclavicular joint laterally or sternoclavicular joint medially often results in a physeal fracture and as such, can go unrecognized or be mistaken for a joint dislocation. Radiographic assessment is challenging, particularly when the epiphysis is not yet ossified. However, MR imaging allows for visualization of the cartilage, periosteum and perichondrium, and ligaments of the affected joints. Lateral clavicle physeal injuries can be categorized by the Dameron and Rockwood system, the pediatric correlate to the Rockwood classification of adult acromioclavicular joint injuries. Medial clavicle physeal fractures, similar to adult sternoclavicular joint dislocations, may result in anterior or posterior displacement. Because of their great ability to heal and remodel, clavicular physeal fractures respond better to conservative management than true acromioclavicular or sternoclavicular joint dislocations. Therefore, it is essential to recognize the true nature of these injuries, as there are implications for successful treatment and appropriate prognosis.

Capsular remnant in the rotator cuff footprint is a novel arthroscopic finding may indicate the etiology of the tear.

PURPOSE: The aim of the study was that the capsule remnant is a common indicator of sub-acromial impingement syndrome and bursal side onset rotator cuff tears. METHODS: Sixty-three patients with capsule remnants in the rotator cuff footprint (Study group) were detected, while the 53 patients did not have any remnant on the tendon footprint (Control group) between 2015 and 2020 were included. Demographic data of patients, such as age, gender, and operated side information were obtained from the archive files. Acromion type, presence of osteophytes in the acromioclavicular joint, Acromiohumeral Distance (AHD), Acromial Index (AI), Critical Shoulder Angle (CSA), and Coracoacromial Ligament (CAL) degeneration values were evaluated from preoperative MRI, radiographic images, and arthroscopic video recordings. RESULTS: Severe stages of CAL degeneration were observed in 82.5% of the patients who had capsule remnant (p: 0.001). While type 2 acromion was found in 61.9%, and also acromioclavicular joint osteophyte was found in 58.7% of the patients in the study group. The mean AHD was 8.22 ± 1.56 mm in the study group and 9.2 ± 1.3 mm in the control group. The mean CSA was 43.3 ± 4.9 in the study group and 40.8 ± 4.2 in the control group. The AI was measured as 0.8 ± 0.1 in the study group and 0.8 ± 0.01 in the control group. As a result of these measurements, a statistical difference was found between the two groups in terms of type 2 acromion ratio (p < 0.001), presence of osteophytes in the acromioclavicular joint (p < 0.001), mean acromio-humeral distance (p < 0.001), critical shoulder angle (p = 0.004), and acromial index values (p < 0.001). CONCLUSION: The findings of sub-acromial impingement syndrome were found to be more prominent in patients with full-thickness degenerative tear and findings of capsular remnant in the footprint. If the presence of the current finding is detected during glenohumeral arthroscopy, sub-acromial impingement syndrome should be examined in more detail to reveal the underlying cause and prevent a recurrence.

Acromion morphology is associated with glenoid bone loss in posterior glenohumeral instability.

BACKGROUND: The acromion morphology in a shoulder with posterior instability differs from that of a shoulder without glenohumeral instability. Specifically, the acromion with a flatter sagittal tilt, greater posterior acromial height, and less posterior coverage is associated with posterior instability. However, the association between acromion morphology and glenoid bone loss (GBL) in the setting of posterior glenohumeral instability has not previously been investigated. The purpose of this study was to determine whether acromial morphology influences the extent or pattern of posterior GBL in a cohort of patients with posterior glenohumeral instability. METHODS: This multicenter retrospective study identified 89 shoulders with unidirectional posterior glenohumeral instability. Total area GBL was measured using the best-fit circle method on magnetic resonance imaging (MRI). Shoulders were divided into 3 groups: (1) no GBL (n = 30), (2) GBL 0%-13.5% (n = 45), or (3) GBL ≥13.5% (n = 14). Acromion measurements were performed on MRI and included acromial tilt, posterior acromial height, anterior acromial coverage, and posterior acromial coverage. RESULTS: Patients without GBL had a steeper acromial tilt (58.5° ± 1.4°) compared with those with 0%-13.5% GBL (64.3° ± 1.5°) or GBL ≥13.5% (67.7° ± 1.8°) (P = .004). Patients without GBL also had greater posterior coverage (65.4° ± 1.7°) compared with those with GBL (60.3° ± 1.4°) (P = .015). Posterior acromion height was not significantly different among groups. CONCLUSION: The results demonstrate that an acromion with a flatter sagittal tilt and less posterior coverage is associated with GBL in the setting of posterior glenohumeral instability. This is important to consider as posterior GBL has been identified as a risk factor for failure of posterior soft tissue-stabilizing procedures.

Effect of reverse shoulder arthroplasty humeral component retroversion on acromial strain.

INTRODUCTION: Acromion and scapular spine stress fractures can be catastrophic complications following reverse shoulder arthroplasty (RSA). A variety of host, implant, and technical factors have been identified that increase the risk of this complication. The glenoid component in particular has been closely evaluated for its impact on rates of stress fractures following RSA. The goal of this biomechanical study is to evaluate if humeral stem version has an impact on acromion and scapular spine strain after RSA. METHODS: Eight cadaveric specimens were tested on a custom dynamic shoulder frame. Commercially available RSA components were implanted with the humeral component inserted in 0° of retroversion. Acromion and scapular spine strain were measured at 0°, 30°, and 60° of abduction using strain rosettes secured to the acromion and scapular spine in the typical locations for Levy type II and type III stress fractures, respectively. The humeral stem was then removed and reimplanted in 30° of retroversion and the measurements were repeated. Student t test was performed to analyze the relationship between humeral stem version and acromion and scapular spine strain at various abduction angles. RESULTS: Strain at the both the acromion and scapular spine were found to have no significant difference at any abduction angle when comparing 0° and 30° version of the humeral stem. With 0° and 30° versions pooled together, there is significantly lower acromion and scapular spine strain at 60° of abduction when compared to 0° of abduction (strain at 0° abduction - strain at 60° abduction: acromion 313.1 µêœª; P = .0409, Scapular spine 304.9 µêœª; P = .0407). There was no significant difference in strain at either location when comparing 0° of abduction to 30° of abduction and when comparing 30° of abduction to 60° of abduction. CONCLUSIONS: This biomechanical study found no significant difference in scapular spine and acromion strain after RSA when comparing variations in humeral stem version. There does appear to be lower strain at both the acromion and scapular spine at 60° of abduction when compared to 0° of abduction regardless of stem version.

Radiographic and anatomic variations on postoperative acromion fractures after inlay and lateralized reverse shoulder arthroplasty.

INTRODUCTION: Postoperative fracture of the acromion is a complication uniquely more common after reverse shoulder arthroplasty (RSA) than other forms of shoulder arthroplasty. There is limited knowledge regarding the etiology of these fractures or the anatomic risk factors. The purpose of this study is to identify associations of the acromioclavicular (AC) joint and relative humeral and glenoid positioning on the occurrence of acromial fractures after RSA. METHODS: A retrospective case-controlled study was performed on primary RSA patients treated by a single surgeon from September 2009 to September 2019. Patients with a postoperative acromion fracture were matched in a 3:1 ratio based on gender, indication, and age to those without a fracture and with a 2-year minimum follow-up. Preoperative and the immediate postoperative radiographs were reviewed by 2 investigators to measure critical shoulder angle, acromion-humeral interval, global lateralization, delta angle, preoperative glenoid height, and the level of inlay or onlay of the humeral stem. The morphology, width, and stigmata of osteoarthritis in the AC joint were assessed using computed tomography scans taken preoperatively. RESULTS: Of a total of 920 RSAs performed, 47 (5.1%) patients suffered a postoperative acromion fracture. These patients were compared with a control group of 141 patients, with a mean age of 76.4 years and similar distributions of gender and surgical indication. Patients in both groups had similar preoperative glenoid height (P = .953) and postoperative degree of inset or offset of humeral implant relative to the anatomic neck (P = .413). There were no differences in critical shoulder angle, acromion-humeral interval, global lateralization, and delta angle both preoperatively and postoperatively between the fracture and nonfracture groups. Computed tomography analysis also showed no differences in AC joint morphology (P = .760), joint space (P = .124), and stigma of osteoarthritis (P = .161). CONCLUSION: There was no relation between the features of the AC joint and the anatomic parameters of the humerus relative to the glenoid and acromion on postoperative acromion fractures after RSA.

The biomechanical effects of acromial fracture angulation in reverse total shoulder arthroplasty.

BACKGROUND: The biomechanical changes and treatment guidelines on acromial fracture after reverse shoulder arthroplasty (RSA) are still not well understood. The purpose of our study was to analyze the biomechanical changes with respect to acromial fracture angulation in RSA. METHODS: RSA was performed on 9 fresh-frozen cadaveric shoulders. An acromial osteotomy was performed on the plane extending from the glenoid surface to simulate an acromion fracture. Four conditions of acromial fracture inferior angulation were evaluated (0°, 10°, 20°, and 30° angulation). The middle deltoid muscle loading origin position was adjusted based on the position of each acromial fracture. The impingement-free angle and capability of the deltoid to produce movement in the abduction and forward flexion planes were measured. The length of the anterior, middle, and posterior deltoid was also analyzed for each acromial fracture angulation. RESULTS: There was no significant difference in the abduction impingement angle between 0° (61.8° ± 2.9°) and 10° angulation (55.9° ± 2.8°); however, the abduction impingement angle of 20° (49.3° ± 2.9°) significantly decreased from 0° and 30° angulation (44.2° ± 4.6°), and 30° angulation significantly differed from 0° and 10° (P < .01). On forward flexion, 10° (75.6° ± 2.7°), 20° (67.9° ± 3.2°), and 30° angulation (59.8° ± 4.0°) had a significantly decreased impingement-free angle than 0° (84.2° ± 4.3°; P < .01), and 30° angulation had a significantly decreased impingement-free angle than 10°. On analysis of glenohumeral abduction capability, 0° significantly differed (at 12.5, 15.0, 17.5, and 20.0N) from 20° and 30°. For forward flexion capability, 30° angulation showed a significantly smaller value than 0° (15N vs. 20N). As acromial fracture angulation increased, the middle and posterior deltoid muscles of 10°, 20°, and 30° became shorter than those of 0°; however, no significant change was found in the anterior deltoid length. CONCLUSIONS: In acromial fractures at the plane of glenoid surface, 10° inferior angulation of the acromion did not interfere with abduction and abduction capability. However, 20° and 30° of inferior angulation caused prominent impingement in abduction and forward flexion and reduced abduction capability. In addition, there was a significant difference between 20° and 30°, suggesting that not only the location of the acromion fracture after RSA but also the degree of angulation are important factors for shoulder biomechanics.

Surgical treatment of a symptomatic os acromiale by arthroscopy-assisted double-button fixation: a case report.

CASE: We present the case of a symptomatic os acromiale in a 51-year-old female patient. Arthroscopy-assisted treatment was performed using a double-button fixation system and additional suture cerclage. The patient presented with complete radiographic bone union, pain relief, improved range of motion and did not require hardware removal at the 12-month follow-up. CONCLUSION: The achievement of persistent consolidation between the two fragmented bone surfaces, without further need for hardware removal and improved clinical outcome, suggests that our minimally invasive technique is appropriate for this specific indication. To our knowledge, this technique has not been described in the literature yet.

Nonunion of the so-called acromion: a systematic review with consideration of the terminology.

INTRODUCTION: There is no widely accepted standard for the classification and treatment of traumatic acromion/scapular spine fracture nonunion due to the scarcity of this condition and the confusion of terminology. MATERIALS AND METHODS: PubMed and Scopus were searched using "scapular fracture" and "acromion fracture" or "scapular spine fracture" as search terms. The inclusion criteria were English full-text articles concerning acromion/scapular spine fracture nonunion that described patient characteristics and presented appropriate images. The exclusion criteria were cases without appropriate images. Citation tracking was conducted to find additional articles and notable full-text articles written in other languages. Fractures were classified using our newly proposed classification system. RESULTS: Twenty-nine patients (19 men, 10 women) with 29 nonunions were identified. There were four type I, 15 type II, and 10 type III fracture nonunions. Only 11 fractures were isolated. The mean period from initial injury to final diagnosis was 35.2 ± 73.2 months (range 3-360 months) (n = 25). The most frequent cause of delayed diagnosis was conservative treatment for fracture in 11 patients, followed by oversight by the physician in 8. The most common reason for seeking medical advice was shoulder pain. Six patients received conservative therapy, and 23 received operative treatment. Fixation materials included various plates in 15 patients, and tension band wiring in 5. Bone grafting was performed in 16 patients (73%, 16/22). Of the 19 surgically treated patients with adequate follow-up, the outcome was rated excellent in 79%. CONCLUSIONS: Isolated acromion/scapular spine fracture nonunion is rare. Fracture type II and III, arising in the anatomical scapular spine, accounted for 86% of the fractures. Computed tomography is required to prevent fracture oversight. Surgical therapy produces good stable results. However, it is important to select the appropriate surgical fixation method and material after considering the anatomical characteristics of the fracture and stress on the fractured portion. LEVEL OF EVIDENCE: V.

The combined utilization of predictors seems more suitable to diagnose and predict rotator cuff tears.

BACKGROUND: Morphological markers presenting the lateral extension of acromion and the greater tuberosity of humerus were proposed to diagnose and predict rotator cuff tears (RCTs) in recent years, but few studies have addressed the combined performance when using two predictors together. As a presence of a RCT may be associated with the impingement caused by both acromion and the greater tuberosity, we believe a combined utilization of predictors could result in a better diagnostic and predictive performance than using a single predictor. The aim of this study is to (i) explore whether the combination is more efficient to predict and diagnose RCTs; (ii) find out which combination is the most superior screening approach for RCTs. METHODS: This was a retrospective study and patients who visited our hospital and were diagnosed with or without partial-thickness or full-thickness RCTs via magnetic resonance imaging from January 2018 to April 2022 were enrolled and classified into two groups respectively. Four predictors, the critical shoulder angle (CSA), the acromion index (AI), the greater tuberosity angle (GTA) and the double-circle radius ratio (DRR) were picked to participate in the present study. Quantitative variables were compared by independent samples t tests and qualitative variables were compared by chi-square tests. Binary logistic regression analysis was used to construct discriminating combined models to further diagnose and predict RCTs. Receiver operating characteristic (ROC) curves were pictured to determine the overall diagnostic performance of the involved predictors and the combined models. RESULTS: One hundred and thirty-nine shoulders with RCTs and 57 shoulders without RCTs were included. The mean values of CSA (35.36 ± 4.57 versus 31.41 ± 4.09°, P < 0.001), AI (0.69 ± 0.08 versus 0.63 ± 0.08, P < 0.001), DRR (1.43 ± 0.10 versus 1.31 ± 0.08, P < 0.001) and GTA (70.15 ± 7.38 versus 64.75 ± 7.91°, P < 0.001) were significantly higher in the RCT group than for controls. Via ROC curves, we found the combined model always showed a better diagnostic performance than either of its contributors. Via logistic regression analysis, we found the values of both predictors over their cutoff values resulted in an increasement (20.169-161.214 folds) in the risk of having a RCT, which is more than that by using a single predictor only (2.815 -11.191 folds). CONCLUSION: The combined utilization of predictors is a better approach to diagnose and predict RCTs than using a single predictor, and CSA together with DRR present the strongest detectability for a presence of RCTs.

Nonoperative treatment of acromial fractures following reverse shoulder arthroplasty: clinical and radiographic outcomes.

BACKGROUND: Acromion/scapular spine fractures (ASFs) remain a challenging complication following reverse shoulder arthroplasty (RSA). Historically, nonoperative management has been the treatment of choice, with variable results. The purpose of this study is to report on both clinical and radiographic outcomes of nonoperative treatment. A new subclassification of Levy type II acromion fractures will be proposed, and outcomes will be evaluated in relation to the modified Levy classification. METHODS: Forty-four patients diagnosed with ASF following RSA were matched 1:3 to a control group based on gender, age, and preoperative function. All ASF patients were treated nonoperatively. Patient-reported outcome measures, consisting of American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Simple Shoulder Test, Single Assessment Numerical Evaluation, visual analog scale pain and function scores, satisfaction, and active range of motion were gathered preoperatively and at the most recent follow-up. Outcomes were stratified based on fracture type. Radiographic findings including fracture union, scapular rotation, progressive notching, and osteolysis were reviewed from latest follow-up and compared with initial postoperative films. RESULTS: ASFs were identified at a median of 2 months following RSA (8 type I; 22 type II; 14 type III), followed for a median of 37 months and compared to 108 matched controls. Patients with ASF had inferior clinical outcomes with a higher rate of dissatisfaction (27.8%) when compared to controls. Lateral fracture subtypes (I and IIA) were similar to controls and had little impact on outcomes. However, medial fracture subtypes (type IIB, IIC, and III) demonstrated inferior outcomes when compared to controls, with type III fracture patients demonstrating no improvement from baseline. The overall nonunion rate was 61.4%, with high rates of scapular rotation and osteolysis in medial fracture subtypes. Nonunion was associated with a higher incidence of secondary radiographic findings, including scapular rotation, progressive notching, and osteolysis. CONCLUSION: Results of nonoperative treatment of ASF following RSA differs based on fracture location. Fractures that occur at or medial to the glenoid face (IIB, IIC, III) demonstrate high rates of unsatisfactory results and worse clinical outcomes. Concerning radiographic findings of scapular tilt, progressive scapular notching and osteolysis were seen at a higher rate with medial fracture types and fracture nonunions.

Acromial fractures following reverse shoulder arthroplasty: the role of the acromial morphology and a comparison of clinical outcomes.

BACKGROUND: The purpose was to evaluate the relationship between acromial morphology and the location of acromial fractures following reverse shoulder arthroplasty and determine whether fracture location and displacement impact clinical outcomes. METHODS: We performed a multicenter retrospective review of reverse shoulder arthroplasties complicated by acromial fractures. Radiographs were compared to determine the differences in acromial morphology, as well as fracture orientation and pattern, between patients with Levy type I (n = 17) and Levy type II (n = 25) fractures. Patients with a minimum of 2 years' follow-up were selected to examine the association between clinical outcomes and fracture location and displacement. Twenty-two patients were stratified based on whether they achieved the minimal clinically important difference (MCID) in the American Shoulder and Elbow Surgeons score (20 points). The groups were then compared regarding fracture location and displacement using measurements such as the acromiohumeral distance. RESULTS: The Levy type I group had a higher acromial slope than the Levy type II group (127° vs. 117°, P < .001). Levy type I fractures had a transverse pattern occurring in the coronal plane, whereas Levy type II fractures had an oblique pattern occurring in the sagittal plane (P < .001). At final follow-up, 12 of 22 patients (55%) achieved the MCID. Those who did not achieve the MCID had more displaced fractures including a lower acromiohumeral distance (8 mm vs. 20 mm, P = .007). There was no difference in the distribution of Levy type I and type II fractures based on the MCID cutoff (P = .093). CONCLUSION: An increased acromial slope is associated with transverse fractures in the Levy I region, whereas a lower acromial slope is associated with oblique fractures in the Levy II region. Overall, 55% of patients achieved the MCID at mid-term follow-up. The outcomes of those who did not achieve the MCID became worse postoperatively, and this was associated with increased fracture displacement.

Anatomical variants of the acromioclavicular joint influence its visibility in the standard MRI protocol in patients aged 18-31 years.

PURPOSE: Visualization of a structure in orthogonal planes is essential for correct radiological assessment. The aim was to assess the utility of the standard MRI protocol for the shoulder in the assessment of the acromioclavicular joint (ACJ). METHODS: A total of 204 MRI scans of the shoulder were re-reviewed. Visibility of the ACJ in orthogonal planes was assessed, and the type of acromion and the angle between the ACJ and the glenoid cavity were assessed by two observers. RESULTS: Agreement in the assessment of ACJ visibility was moderate to substantial. The ACJ was visible in the three anatomical views in 48% (confidence interval [CI] 95% = [41-54%]) of the examinations, and no significant difference regarding gender or age was noticed. The mean angle between the ACJ and the glenoid cavity was 41.12 deg. CI95% = (39.72, 42.53) in the axial plane, 33.39 deg. CI95% = (31.33, 35.45) in the coronal plane and 52.49 deg. CI95% = (50.10, 54.86) in the sagittal plane. When the ACJ was visible in the sagittal and axial planes, significant differences were noticed in the remaining planes (p < .05). CONCLUSION: Anatomical variations of the ACJ influence its visibility in the standard MRI protocol for examining the shoulder, making this protocol insufficient for ACJ assessment in the examined population.

The reliability and effectiveness of shoulder joint evaluation by ultrasonography in stroke patients: deltoid muscle thickness, acromion-humeral distance, acromion-lesser tuberosity distance.

[Purpose] This study aimed to evaluate the reliability of the intraclass correlation coefficient (ICC) in measuring deltoid muscle thickness (DMT) at different angles, acromion-humeral distance (AHD), and acromion nodule tuberosity (ALT) distance in a resting position in stroke patients using ultrasonography. [Participants and Methods] We included 40 stroke patients. During the measurement of parameters by ultrasonography, we measured the deltoid muscle thickness on both sides at three test angles (0°, 30°, and 60° abduction) and AHD and ALT on both sides at 0° angle. The ICC was used to assess intra- and interrater reliability. The relationship between the hemiplegic and non-hemiplegic sides and each angle were analyzed using a two-way repeated-measure analysis of variance (ANOVA). [Results] When the shoulders were at three testing angles (0°, 30°, and 60° abduction), the deltoid muscle thickness of the hemiplegic and non-hemiplegic sides showed good reliability; the AHD and ALT of the shoulder joint at 0° angle equally showed good reliability. There was a significant difference in each abduction angle of the shoulder joint between the thickness of the hemiplegic and non-hemiplegic deltoid. [Conclusion] Measuring deltoid muscle thickness by ultrasonography showed excellent reliability and can be used in stroke patients.

The association between acromial anatomy and articular-sided partial thickness of rotator cuff tears.

BACKGROUND: Acromial anatomy has been found to be correlated with degenerative full-thickness rotator cuff tears in current studies. However, research on the relationship between acromial anatomy and articular-sided partial thickness of rotator cuff tears (PTRCTs) is still lacking. The purpose of this study was to evaluate whether these imaging graphic parameters exhibit any association between acromial anatomy and degenerative articular-sided PTRCTs. METHODS: Between January 2016 and December 2018, a total of 91 patients without a history of trauma underwent arthroscopy as an articular-sided PTRCT group. In the control group, with age- and sex-matched patients, we selected 91 consecutive outpatient patients who underwent shoulder magnetic resonance imaging (MRI) because of shoulder pain and an MRI diagnosis of only synovial hyperplasia and effusion. MRI was used to measure the acromial type, acromiohumeral distance (AHD), lateral acromial angle (LAA), acromion index (AI), and critical shoulder angle (CSA) by 2 independent observers. RESULTS: The acromion type, AHD and LAA showed no difference between degenerative articular-sided PTRCTs and controls (P = 0.532, 0.277, and 0.108, respectively). AI and CSA were significantly higher in degenerative articular-sided PTRCTs (P = 0.002 and 0.003, respectively). A good correlation was found between AI and CSA to measurement(Pearson correlation coefficient = 0.631). CONCLUSIONS: Our study revealed that higher AI and CSA were found in degenerative articular-sided PTRCTs. Acromial anatomy with a large acromial extension was associated with the occurrence of degenerative articular-sided PTRCTs.

WITHDRAWN: Higher coracoacromial ligament thickness, critical shoulder angle and acromion index are associated with rotator cuff tears in patients who undergo arthroscopic rotator cuff repair.

PURPOSE: To evaluate the effect of several shoulder anatomical parameters in the development of rotator cuff tear (RCT). METHODS: Between 2014 and 2018, all consecutive patients who underwent arthroscopic rotator cuff repair due to full-thickness rotator cuff tear with a minimum 2-year follow-up were identified. Inclusion criteria were (1) age>18 years, (2) patients with degenerative RCT, (3) full-thickness RCTs, (4) patients underwent arthroscopic RCR due to unresponsive conservative treatment, (5) minimum 2-year follow-up period. Exclusion criteria were traumatic RCT, history of previous shoulder surgery, shoulder deformity, neurologic or neuromuscular dysfunction, glenohumeral and/or acromioclavicular joint arthritis, cuff-tear arthropathy, history of fracture around shoulder and inadequate or low-quality magnetic resonance images (MRI). Acromion index (AI), Critical shoulder angle (CSA), Coracoacromial ligament (CAL) thickness, Subacromial space (SS) width, Acromiohumeral distance (AHD), CAL/SS ratio, Lateral acromial angle (LAA) and glenoid version angle (GVA) parameters were measured on MRI. Intra- and interobserver reliability were measured. Regression analysis was used to evaluate the association between anatomical parameters and RCT development. Receiver operating curves (ROC) were created for independent risk factors. The correlation between measurement parameters were evaluated. RESULTS: There were 1029 patients met the inclusion criteria. After exclusions, 437 patients were included. Age- and sex matched 437 patients without any shoulder pathologies were selected as control group. There was almost perfect intra- (ICC>0.85) and interobserver (ICC> 0.81) reliability regarding all measurement parameters. There was significant difference between RCT group and control group regarding AI (0.67±0.07 vs. 0.61±0.08, p<0.001), CSA (33.58±3.93 vs. 31.50±4.01, p<0.001), CAL thickness (1.81±0.64 vs. 1.53±0.50, p<0.001), CAL/SS ratio (0.29±0.14 vs. 0.23±0.10, p<0.001) and GVA (-16.69±6.69 vs. -15.37±5.95, p=0.002) parameters. AI (OR: 1.998, P<0.001), CAL thickness (OR: 2.801, p<0.000) and CSA (OR: 3.055, p<0.001) were found to be independently associated with the increased risk of RCT development. Area under curve (AUC) of the AI, CSA, and CAL thickness were 71.4%, 71.3%, and 70.2%, respectively. Cut-off values for AI, CSA, and CAL thickness were 0.62, 36.4° and 1.47 mm, respectively. There was significantly positive strong correlation between AI and CSA (p<0.001, r=0.814). CONCLUSION: Higher AI, CSA and CAL thickness independently associated with full-thickness RCT development. In clinical practice, these parameters may be useful in the prediction of rotator cuff rupture.