Giant Cell Tumor of the Acromion: Case Report and Literature Review.

BACKGROUND/AIM: Giant cell tumor of bone (GCTB) is a locally aggressive neoplasm that typically occurs in the ends (epiphyses) of long bones of young adults. Flat bones are uncommon sites of involvement. Herein, we describe an unusual case of pathologically proven GCT of the acromion. CASE REPORT: The patient was a 39-year-old woman with no history of trauma who presented with a 3-month history of right posterior shoulder pain. Physical examination revealed mild swelling and tenderness in the posterior aspect of the right shoulder. Plain radiograph showed a purely lytic lesion, suggestive of a bone tumor. Computed tomography demonstrated an intraosseous lytic lesion with associated cortical thinning and lack of periosteal reaction. On magnetic resonance imaging, the lesion exhibited slightly higher signal intensity compared to skeletal muscle on T1-weighted sequences and heterogeneous high signal intensity on T2-weighted sequences. Strong enhancement was observed following gadolinium administration. The lesion was treated by extensive curettage with adjuvant therapy comprising ethanol and the remaining cavity was filled with polymethylmethacrylate bone cement. Histologically, the lesion was composed of round or spindle-shaped mononuclear cells admixed with numerous osteoclast-like giant cells. Immunohistochemically, the mononuclear neoplastic cells were diffusely positive for H3.3 G34W. The patient was asymptomatic and there was no evidence of local recurrence or distant metastasis 5 months after surgery. CONCLUSION: Although rare, acromial GCTB should be considered in the differential diagnosis of posterior shoulder pain, especially in young and early middle-aged adults.

Anatomical Variants Identified on Computed Tomography of Oropharyngeal Carcinoma Patients.

Background and Objectives: Anatomical variations in the head, neck and chest are common, and are observed as occasional findings on computed tomography (CT). Although anatomical variations are mostly asymptomatic and do not cause any negative influence on the body function, they may jeopardize diagnosis and may be confused with pathological conditions. The presence of variations may also limit surgical access during tumor removal. The aim of this study was to investigate the prevalence of six anatomical variations-os acromiale, episternal ossicles, cervical rib, Stafne bone cavity, azygos lobe and tracheal bronchus-in an open-access computed tomography dataset obtained from oropharyngeal cancer patients. Materials and Methods: A total of 606 upper-chest and neck computed-tomography scans (79.4% male and 20.6% female) were retrospectively investigated. Sex difference was evaluated using the z-test for two proportions. Results: Os acromiale, episternal ossicles, cervical rib, Stafne bone cavity, azygos lobe, and tracheal bronchus were present in 3.1%, 2.2%, 0.2%, 0%, 0.3% and 0.5%, respectively, of all patients. Os acromiale was identified as meso-acromion in 86.6%, and as pre-acromion in 17.4%, of all acromia. Episternal ossicles were present unilaterally in 58.3%, and bilaterally in 41.7%, of all sterna. Only the cervical rib showed a sex difference in prevalence. Conclusions: awareness of these variations is important for radiologists interpreting head, neck and chest CTs; for example, those of oropharyngeal cancer patients. This study also illustrates the applicability of publicly available datasets in prevalence-based anatomical research. While most of the variations investigated in the present study are well-known, the episternal ossicles are not well explored, and need further investigation.

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.

Anterolateral Acromioplasty Does Not Change the Critical Shoulder Angle and Acromion Index in a Clinically Relevant Amount.

PURPOSE: Assessment on whether radiographic parameters of the acromion measured in radiographs change significantly after anterolateral acromioplasty. METHODS: This retrospective study included patients that underwent an arthroscopic anterolateral acromioplasty between January 2014 and September 2020. n = 435 subjects with high-quality preoperative and postoperative radiographs according to Suter-Henninger criteria were included in the final assessment. All measurements were independently performed by the first and second author in a blinded fashion using dicomPACS software: acromion index (AI), critical shoulder angle (CSA), lateral acromial angle (LAA), beta angle, acromio-humeral distance (AHD), Aoki angle, frontal supraspinatus outlet angle (FSOW), and acromion type, according to Bigliani. SPSS software was used for statistical analysis. RESULTS: The beta angle and the CSA did not significantly change after operation (alpha power 0.32 and 0.11, respectively). In a subgroup analysis of patients with a pathological CSA >35° (n = 194), the CSA changed from 38.62 (range: 35.08-47.52, SD 2.83) to 38.04 (range: 29.18-48.12, SD 3.77) postoperatively (P = .028) (Fig 8). All other parameters changed significantly after operation (AI, AHD, FSOW, and Aoki; P = .001, LAA; P = .039) (Fig. 9). The interobserver and intraobserver reliability was good to excellent in the majority of measured values. Mean patient age was 59.2 years (range: 18.1-87.1; SD 11.3), mean height was 1.73 meters (range: 1,50-1.98, SD 0.09), mean weight was 80.2 kg (range: 37.0-133.0, SD 16.68), and mean body mass index was 26.6 (range: 0.0-46.1, SD 4.73). CONCLUSION: Anterolateral acromioplasty producing a flat acromion undersurface did not result in a significant change of the CSA in the study population. Pathological preoperative CSA values of >35° were significantly reduced but not to normal values, but only by a small amount that puts the clinical relevance into question. LEVEL OF EVIDENCE: IV, diagnostic study, case series.

Evaluation of critical shoulder angle and acromion index in patients with anterior shoulder instability and rotator cuff tear.

OBJECTIVE: The aim of this study was to evaluate glenohumeral morphologic differences and their correlation between glenohumeral instability and rotator cuff pathology. METHODS: Two-hundred radiographs and 100 MRI scans of 100 patients in whom the diagnosis of Anterior Shoulder Instability (Anl) or Rotator Cuff Tear (RCT) was arthroscopically verified were retrospectively identified and included in the study. All the patients were categorized into two groups: 50 patients with Anl (23 female, 28 male; mean age = 29 ± 7.4) and 50 patients with RCT (28 female, 22 male). Two separate control groups were then formed, one of which included contralateral shoulders of patients in the AnI group, and the other consisted of contralateral shoulders of patients in the RCT group. The x-ray and MRI scans were examined by an orthopedic surgeon and a radiologist. The Acromial Index (AI) and the Critical Shoulder Angle (CSA) were measured on true anteroposterior shoulder radiographs; Glenoid Inclination (GI), Glenoid Version (GV), and Acromion Angulation (AA) were measured on MRI. RESULTS: In the AnI group, the measurements were as followed: AI, 0.66 ± 0.03; CSA, 33 ° ± 2.85; GI, 3.4° ± 6.2; GV, 4.1 ± 4.3; and AA, 12.9 ± 8.3. In the RCT group, AI 0.71 ± 0.04; CSA, 36° ± 2.69; GI, 9.1 ± 5; GV, 6.7 ° ± 5.7; and AA, 14.3° ± 8.7. A moderate correlation was found between CSA and GI (r = 0.41, P = 0.001) and between AI and GI (r = 0.42, P = 0.014). A weak correlation was found between AI and GI in the AnI group (r = 0.22, P = 0.001). The inter- and intra-observer intraclass correlation coefficients were respectively 0.81 and 0.84 for AI, 0.88 and 0.92 for CSA, 0.72 and 0.76 for GI, 0.69 and 0.73 for GV, and 0.72 and 0.77 for AA. CONCLUSION: The results of this study have shown that lower AI, GI, and antevert GV may be associated with AnI. Investigating CSA, AI, and GV could be useful for diagnostic evaluation of patients with AnI. LEVEL OF EVIDENCE: Level III, Diagnostic Study.

Increased acromiohumeral distance in a double-row arthroscopic rotator cuff surgery compared to a single-row surgery after 12 months.

BACKGROUND: Arthroscopic rotator cuff surgery is an effective treatment for rotator cuff tears with the considered use of double-row repair techniques becoming popular in the last decade. We aim to compare the effects of double- and single-row arthroscopic rotator cuff repairs (ARCR) on repair integrity (RI) and acromiohumeral distance (AHD). METHODS: In this observational study, we retrospectively identified 98 patients with degenerative rotator cuff tear treated with arthroscopic rotator cuff repair between 2016 and 2019. We excluded 22 patients with partial-thickness tears, 15 with associated subscapularis or SLAP tears, 13 with massive tears, and 5 patients lost to follow-up; we included 43 patients who had ARCR for full-thickness cuff tear and clinical, radiologic follow-up. Of these 43 patients, 23 are grouped as double-row repair group (DRG) and 20 as single-row repair group (SRG). A minimum of 12 months after the surgery, bilateral shoulder MRIs were obtained. Contralateral shoulders without asymptomatic rotator cuff tears served as a control group (CG). The operating surgeon and two other surgeons experienced in arthroscopy blindly measured the AHD and determined the RI at the control MRIs in all groups. Functional assessments relied on UCLA and qDASH Scores. RESULTS: The mean age was 57.89 (45-78) years, and the mean follow-up time was 28,65 (21-43) months. The mean AHD of the CG was 9.7 ± 0.96 mm, the preoperative AHD of DRG was 8.62 ± 1.45 mm, and SRG was 9.71 ± 0.95 mm. The postoperative mean AHD of DRG 9.61 ± 1.83 mm and SRG was 10.21 ± 1.97 mm. AHD differences between the preoperative and postoperative groups were significant (P=0.009). The increase of the AHD in the double-row group was significantly higher than the single-row group (P=0.004). There was a high correlation between the RI and DASH scores (P=0.005). RI did not correlate with the repair method (P=0.580). CONCLUSION: Although double-row repairs can maintain greater AHD than single-row repairs in the clinical setting, this difference did not affect functional results. Regardless of the surgical intervention, functional results are favourable if RI is achieved. LEVEL OF EVIDENCE: Level III, Retrospective Cohort Study.

Where and what damage occurs at the acromial undersurface in patients with rotator cuff tears?

BACKGROUND: The gross pathology of the acromial undersurface in shoulders with rotator cuff tears with subacromial impingement is not completely understood. Many researchers have focused on damage to the anterior one-third area of the acromial undersurface, but few have studied the middle and posterior one-third areas. The purpose of this study was to clarify where and what damage occurs at the acromial undersurface in patients with rotator cuff tears. METHODS: We performed arthroscopic shoulder (n = 182, all with rotator cuff tears; mean age, 64.9 ± 8.4 years) and cadaveric shoulder (n = 23, 14 intact cuffs and 9 rotator cuff tears; mean age, 74.8 years) evaluations to observe the extent and degree of damage to the acromial undersurface. We statistically analyzed the association between the severity of the damage to the acromial undersurface (assessed using the Copeland-Levy classification as A0, normal; A1, minor scuffing; A2, major damage; or A3, visualization of bare bone area) and rotator cuff tear size (assessed using the classification of DeOrio and Cofield as partial; small, <1 cm; medium, 1-3 cm; or large or massive, >3 cm). RESULTS: The anterior, middle, and posterior one-thirds of the acromial undersurface were somewhat damaged (class A1-A3) in 92.6%, 90.1%, and 78.6% of shoulders with rotator cuff tears, respectively, according to arthroscopic evaluation. Increasing cuff tear size was significantly associated with worsening degree of damage to the acromial undersurface (P < .001). In the 9 cadaveric shoulders with rotator cuff tears, class A1-A3 damage was identified in the anterior one-third area in 100%, in the middle one-third area in 88.9%, and in the posterior one-third area in 33.3%. In the 14 cadaveric shoulders with a normal rotator cuff, class A1-A3 damage was identified in the anterior one-third area in 35.7%, in the middle one-third area in 14.3%, and in the posterior one-third area in 0.71%. CONCLUSION: Damage to the acromial undersurface in patients with rotator cuff tears occurred at the middle, posterior, and anterior one-third areas, and the degree of damage was related to cuff tear size. Surgeons should evaluate the entire acromial undersurface to check for subacromial impingement damage at the middle and posterior one-third areas as well as the anterior one-third area of the acromial undersurface; this might aid in the treatment of patients with rotator cuff disease or subacromial impingement syndrome.

The value of radiographic markers in the diagnostic work-up of rotator cuff tears, an arthroscopic correlated study.

OBJECTIVE: To evaluate the value of radiographs during the diagnostic work-up of rotator cuff tears, using arthroscopy as reference standard. MATERIALS AND METHODS: This retrospective study included 236 shoulders of 236 patients. All radiographs were evaluated for inferior cortical acromial sclerosis, lateral acromial spur, superior migration of the humeral head, greater tubercle cysts, and subacromial space calcifications. Predictive value of these radiographic signs in predicting rotator cuff tears was determined with arthroscopy as reference standard. RESULTS: According to arthroscopy, 131 shoulders were diagnosed with rotator cuff tears. Seventy-two out of 131 shoulders (55%) had inferior cortical acromial sclerosis, 37 (28%) lateral acromial spur, 21 (16%) superior migration of the humeral head, 7 (5%) greater tubercle cysts and 15 subacromial space calcifications (11%). Inferior cortical acromial sclerosis (P = 0.001), lateral spur (P = 0.001), superior migration (P = 0.002), and cysts (P = 0.03) were significantly and independently associated with rotator cuff tears, whereas subacromial calcifications (p = 0.21) was not. Inferior cortical acromial sclerosis, superior migration, lateral acromial spur, and cysts combined have a positive predictive value of 78%. CONCLUSIONS: The combination of inferior cortical acromial sclerosis, lateral acromial spur, superior migration of the humeral head, and greater tubercle cysts has a high positive predictive value for the presence of full-thickness rotator cuff tears. In patients with a high suspicion for having a rotator cuff tear based on radiographic findings, MRI can be performed directly without the delay and costs caused by an additional ultrasound exam.

Os Acromiale: Reviews and Current Perspectives.

Os acromiale is a developmental defect which results from the lack of an osseous union between the ossification centers of the acromion, leading to the fibrocartilaginous tissue connection. The prevalence of os acromiale is 1% to 15%, and is quite common in the African American population. Os acromiale in adults is easily diagnosed by symptoms and X-ray, particularly on the axillary view; however, the differential diagnosis of adolescents may require MRI or SPECT-CT. Generally, nonoperative therapy for symptomatic os acromiale should be started, including physiotherapy, nonsteroidal anti-inflammatory drugs, and injections. Surgical treatment is indicated after failed conservative treatment. In symptomatic patients with fixable acromiale, the tension band technique should be used to make the anterior aspect of the acromion elevated from the humerus head. In patients with small fragments which are unsuitable for reattachment, excision might be the best therapeutic option and lead to good outcomes. Whether using internal fixation or resection, the arthroscopic technique results in a better outcome and fewer complications, especially in older patients or athletes with overhead movement, because of the high incidence of shoulder impingement or rotator cuff tears which can be treated concurrently.

The Effectiveness of Using the Critical Shoulder Angle and Acromion Index for Predicting Rotator Cuff Tears: Accurate Diagnosis Based on Standard and Nonstandard Anteroposterior Radiographs.

PURPOSE: To explore whether the critical shoulder angle (CSA) and acromion index (AI) on nonstandard anteroposterior (AP) radiographs could be used as parameters for rotator cuff tear (RCT) diagnosis and to determine the optimized parameters. METHODS: This study included 174 patients with RCTs or intact rotator cuffs in whom AP radiographs were obtained at our hospital. The radiographs were assessed by 2 independent radiologists and were grouped according to the Suter-Henninger criteria. The CSA and AI were measured on all films. We performed receiver operating characteristic curve analysis by calculating the area under the curve (AUC) to compare the sensitivity and accuracy of both parameters. RESULTS: Of the 174 enrolled patients, only 47 (27%) met the requirements for standard AP films (types A1 and C1). On standard AP films, both the CSA and AI were significantly different between the RCT and control groups (P < .001 for CSA and P < .001 for AI), with AUCs of 0.86 and 0.80 for the CSA and AI, respectively. On nonstandard AP films (other radiograph types), the mean CSA value was not significantly different between the RCT and control groups (P = .536) whereas the AI showed a significant difference (P = .024). The AUCs were 0.57 for the CSA and 0.64 for the AI. CONCLUSIONS: On standard AP films, both the CSA and AI could predict rotator cuff disorders, and the CSA had a higher diagnostic accuracy than the AI. In contrast, on nonstandard AP films, the diagnostic efficacy of the AI was better than that of the CSA. On the basis of this study, we suggest an evaluation of the AP films of patients before diagnosis to confirm whether the AP films meet the criteria for standard AP films. LEVEL OF EVIDENCE: Level I, diagnostic study.

Coracoacromial morphology: a contributor to recurrent traumatic anterior glenohumeral instability?

BACKGROUND: Although scapular morphology contributes to glenohumeral osteoarthritis and rotator cuff disease, its role in traumatic glenohumeral instability remains unknown. We hypothesized that coracoacromial and glenoid morphology would differ between healthy subjects and patients with recurrent traumatic anterior shoulder instability. METHODS: Computed tomography scans of 31 cadaveric control scapulae and 54 scapulae of patients with recurrent traumatic anterior shoulder instability and Hill-Sachs lesions were 3-dimensionally reconstructed. Statistical shape modeling identified the modes of variation between the scapulae of both groups. Corresponding measurements quantified these modes in relation to the glenoid center (linear offset measures), defined by the best-fit circle of the inferior glenoid, or the glenoid center plane (angles), which bisects the glenoid longitudinally. Distances were normalized for glenoid size. RESULTS: Compared with controls, the unstable coracoids were shorter (P = .004), with a more superior and medial offset of the tip (mean difference [MD], 7 and 3 mm, respectively; P < .001) and an origin closer to the 12-o'clock position (MD, 6°; P < .001). The unstable scapular spines originated closer to the 9-o'clock position (MD, 4°; P = .012), and the unstable acromions were more vertically oriented (MD, 6°; P < .001). The unstable glenoids had an increased height-width index (MD, 0.04; P = .021), had a flatter anterior-posterior radius of curvature (MD, 77 mm; P < .001), and were more anteriorly tilted (MD, 5°; P = .005). CONCLUSIONS: Coracoacromial and glenoid anatomy differs between individuals with and without recurrent traumatic anterior shoulder instability. This pathologic anatomy is not addressed by current soft-tissue stabilization procedures and may contribute to instability recurrence.

Symptomatic, Unstable Os Acromiale.

Management of a persistently symptomatic, unstable os acromiale remains controversial. An unstable os acromiale is an easy diagnosis to miss and should be specifically evaluated for in patients with shoulder pain and a high degree of clinical suspicion. Surgical options include open or arthroscopic excision and open reduction and internal fixation. Open excision of large fragments has had poor results. Arthroscopic treatment is commonly used for small fragments (preacromion), and the technique has also been used in larger fragments (meso-os), but concerns persist over postoperative weakness secondary to shortening of the deltoid lever arm. Open reduction and internal fixation through a transacromial approach has been shown to have predictable union rates but can be complicated by symptomatic implant. Recent biomechanical studies have expanded our understanding of optimal fixation constructs, which may also decrease implant-related issues. Ultimately, the choice of which procedure to use will be dictated by patient factors such as age, activity level, and the nature of rotator cuff pathology. LEVEL OF EVIDENCE:: Level V.

Different acromial roof morphology in concentric and eccentric osteoarthritis of the shoulder: a multiplane reconstruction analysis of 105 shoulder computed tomography scans.

BACKGROUND: The pathomechanisms of eccentric osteoarthritis of the shoulder remain unclear. Although there is increasing evidence of bony differences between shoulders with rotator cuff tears and osteoarthritis, analogous differences have not been identified for primary concentric and eccentric osteoarthritis. This study examined the shape and orientation of the acromial roof as a potential risk factor for the development of posterior glenoid wear. METHODS: We analyzed computed tomography images of 105 shoulders with primary osteoarthritis. Based on the classification of Walch, 45 shoulders had concentric osteoarthritis (Walch A) and 60 shoulders were affected by eccentric osteoarthritis (Walch B; EOA). A comparison of acromial morphology was performed in a multiplanar reconstruction analysis of computed tomography scans. RESULTS: Acromial shape: Acromial length, width, and area were not significantly different. Acromial roof orientation: The acromial roof in EOA was an average of 5° flatter (sagittal tilt; P < .01) and 5° more downward tilted (coronal tilt; P < .01). There was no difference in axial rotation (axial tilt; P = .47). Anteroposterior glenoid coverage: The glenoid in EOA was covered an average of 4° less posteriorly (P = .01) and 4° more anteriorly (P = .04). No differences were shown for overall glenoid coverage. CONCLUSIONS: The acromial roof could play a role in the pathogenesis of EOA. Less posterior support due to a flatter acromion with less posterior glenoid coverage could contribute to static posterior subluxation of the humeral head and posterior glenoid wear. Further biomechanical investigations are needed to confirm these findings.

A simple method to directly evaluate the lateral extension of the acromion: an anatomic study of 128 cadaveric scapulae.

BACKGROUND: The lateral extension of the acromion from the glenohumeral joint is the critical variable that both the acromial index and critical shoulder angle reflect. The purpose of this study was to establish a simple and reproducible method to directly measure the lateral extension of the acromion that will be independent of patient demographic characteristics, scapular rotation, or other morphologic features of the shoulder. METHODS: This study used 128 unpaired cadaveric scapulae with a mean age of 69.4 ± 11.1 years (66 right and 62 left scapulae, 65 female and 63 male cadaveric specimens). The lateral extension of the acromion was measured from the supraglenoid tubercle to the most lateral point of the acromion with a digital caliper placed perpendicular to the scapula long axis. This distance was called the "lateral offset of the acromion." RESULTS: The lateral offset was 2.62 ± 0.72 cm in men and 2.69 ± 0.73 cm in women. The offset was 2.61 ± 0.66 cm in right and 2.70 ± 0.78 cm in left scapulae. The offset in the group aged 46-60 years was 2.85 ± 0.76 cm; in the group aged 61-75 years, it was 2.62 ± 0.76 cm; and in the group aged 76 years or older, it was 2.54 ± 0.60 cm. No significant difference was found between any of the groups. CONCLUSIONS: This study established a simple method to directly measure the lateral extension of the acromion based on the longitudinal axis of the scapula, which eliminates bias that may exist in the acromial index and critical shoulder angle from the position of the scapula and glenoid inclination. The lateral offset was found to be independent of sex, side, or age, limiting bias in a potential future clinical application.

Acromial roof in patients with concentric osteoarthritis and massive rotator cuff tears: multiplanar analysis of 115 computed tomography scans.

BACKGROUND: There is evidence for differences of scapular shape between shoulders with rotator cuff tears (RCT) and osteoarthritic shoulders (OA). This study analyzed orientation and shape of the acromion in patients with massive RCT and concentric OA (COA) in a multiplanar computed tomography (CT) analysis. METHODS: CT scans of 70 shoulders with degenerative RCT and 45 shoulders with COA undergoing primary shoulder arthroplasty were analyzed. The 2 groups were compared in relation of (1) shape of the acromion, (2) its orientation in space, and (3) the anteroposterior glenoid coverage in relation to the scapular plane. RESULTS: Lateral acromial roof extension was an average of 4.6 mm wider and the acromial area was an average of 156 mm2 larger in RCT than in COA (P < .001). Significant differences of the lateral extension of the acromion margin were limited to the anterior two-thirds. Acromial roof orientation in RCT was average of 10.8° more "externally rotated" (axial plane: P < .001) and an average of 7.8° more tilted downward (coronal plane: P < .001) than in COA. The glenoid in RCT was an average of 5.5° (P < .001) more covered posteriorly compared with COA. CONCLUSIONS: A more externally rotated (axial plane), more downward tilted (coronal plane), and wider posterior covering acromion was more frequent in patients with massive RCT than COA.

[Case-control study on polymer polylactic acid absorbable medical film for preventing acromion adhesion after arthroscopic rotator cuff repair].

OBJECTIVE: To study effect of shoulder joint function after rotator cuff repair of polylactic acid absorbable membrane. METHODS: From September 2015 to December 2016, 50 patients diagnosed with rotator cuff tear were selected and divided into treatment group and control group. There were 25 patients in control group, including 12 males and 13 females, with an average age of (48.7±3.5) years old, who received simple arthroscopic rotator cuff repair. There were 25 patients in treatment group, including 11 males and 14 females, with an average age of(49.2±4.1) years old, who performed arthroscopic rotator cuff repair with implanting polylactic acid absorbable membraneon shoulder of rotator cuff. Preoperative and postoperative VAS score, ASES score and UCLA score were recorded and compared between two groups. RESULTS: At 6 months after operation, preoperative VAS score in control group was 5.48±1.12, and decreased as 1.28±0.84 after operation; ASES score before operation was 52.24±4.64, and improved to 86.92±3.20 after operation;preoperative UCLA score improved from 14.36±1.89 before operation to 30.72±1.28 after operation. In treatment group, VAS score decreased from 5.36±1.32 before operation to 1.40±0.71 after operation;preoperative ASES score was 51.04±4.09, and improved to 88.96±2.79 after operation; UCLA score improved from 15.12±1.81 before operation to 32.12±1.33 after operation. There was no significant difference in VAS score between two groups, and ASES score, UCLA score in treatment group was obviously better than control group. CONCLUSIONS: Application of polylactic acid absorbable medical membrane could obviously improve shoulder function, and effectively prevent acromion adhesion after arthroscopic rotator cuff repair.

Predictors of shoulder degeneration in the Kwazulu-Natal population of South Africa / Indicadores de la degeneración del hombro en la poblacion Kwazulu/Natal de Sudáfrica

SUMMARY: The critical shoulder angle and acromion index are conventional radiological tools employed as predictors of shoulder degeneration. As they represent the static components of glenohumeral stability, the scapulo-humeral geometry and underlying subacromial tissue appear as the resultant cause-effect factors. Consequently, the purpose of this study was to investigate the critical shoulder angle and acromion index as interrelated parameters within the South African population. The measurement of both biomechanical parameters was conducted on two-hundred and sixty (n = 260) true AP radiographs. This was a cross-sectional study that also incorporated the demographic representation of the population group which was analysed accordingly. The mean values recorded for both the critical shoulder angle (36.31±5.84º) and acromion index (0.74±0.13) suggested rotator cuff arthropathy. The results confirmed the theories of Nyffeler et al. (2006) and Moor et al. (2012) who alluded to glenoid inclination and the acromial coverage over the humeral head. A significant proportionality correlation, verified by a P value of 0.000, was established between the acromion index and critical shoulder angle which may assist to differentiate between normal asymptomatic shoulders and those with cuff disease. Furthermore, these predictors of shoulder degeneration may present as a preventative tool against tear progression.

RESUMEN: El ángulo crítico del hombro y el índice acromial son herramientas radiológicas convencionales empleadas como indicadores de la degeneración del hombro. Debido a que representan los componentes estáticos de la estabilidad glenohumeral, la geometría escápulo-humeral y el tejido subacromial subyacente aparecen como los factores causa-efecto resultantes. En consecuencia, el propósito de este estudio fue investigar el ángulo crítico del hombro y el índice acromial como parámetros interrelacionados dentro de la población sudafricana. La medición de ambos parámetros biomecánicos se realizó en 260 radiografías antero-posteriores (AP). Se realizó un estudio transversal que también incorporó la representación demográfica del grupo de la población que fue analizada. Los valores medios registrados tanto para el ángulo crítico del hombro (36,31 ± 5,84º) como para el índice del acromión (0,74 ± 0,13) sugirieron una artropatía del manguito rotador. Los resultados confirmaron las teorías de Nyffeler et al. (2006) y Moor et al. (2012) que aludían a la inclinación glenoide y a la cobertura acromial sobre la cabeza humeral. Se estableció una correlación de proporcionalidad significativa, verificada por un valor de P de 0,000, entre el índice acromial y el ángulo crítico del hombro, lo que puede ayudar a diferenciar entre los hombros asintomáticos normales y aquellos con enfermedad del manguito rotador. Además, estos predictores de degeneración del hombro pueden ser útiles como una herramienta preventiva contra la progresión del desgarro.

Bursal-Sided Rotator Cuff Tears: Simple Versus Everted Type.

BACKGROUND: No studies have focused on the everted type of bursal-sided partial-thickness rotator cuff tears (PTRCTs). PURPOSE: To evaluate the radiological characteristics, arthroscopic findings, and clinical and structural outcomes after arthroscopic repair of the everted type of bursal-sided PTRCTs. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Two groups of patients with bursal-sided PTRCTs (simple type, 25 shoulders; everted type, 25 shoulders) were enrolled. The mean age was 59.6 years (range, 47-73 years) and 60.8 years (range, 48-72 years) among patients with the simple and everted type, respectively. The mean follow-up period was 2.7 years (range, 2.0-5.1 years). RESULTS: The everted type always exhibited an acromial spur (hat-shaped, 52%; heel-shaped, 48%) and bony changes in the greater tuberosity (bony spur, 52%; sclerotic changes, 48%). Hat-shaped spurs of the acromion were not observed in the simple type. The everted type showed significantly thicker tendon on magnetic resonance imaging (MRI), as the stump was retracted superomedially (mean thickness: 8.1 ± 1.2 mm vs 5.5 ± 1.1 mm for the everted and simple type, respectively). During arthroscopic repair, additional sutures were needed more often for the everted type than for the simple type (64% vs 16%, respectively). After repair, the tendon margin was uneven and ragged in 16% of shoulders with the everted type. Preoperatively, the visual analog scale (VAS) score for pain during motion and range of motion (ROM) were significantly worse in patients with the everted type than in those with the simple type (VAS score, 7.2 vs 5.6, respectively; ROM for forward flexion, 146.8° vs 156.4°, respectively). Postoperatively, no significant differences in the VAS score, ROM, or clinical outcomes were observed between the 2 groups, with no retears on follow-up MRI in either group. CONCLUSION: The everted type of bursal-sided PTRCTs showed a characteristic hat-shaped acromion, often with bony spurs of the greater tuberosity. On MRI, the tendon stump appeared thickened because of the everted flap. The everted type was more likely to require additional sutures because of an uneven or ragged tendon margin. However, satisfactory clinical and structural outcomes were observed for both the simple and everted types.

The anterior borders of the clavicle and the acromion are not always aligned in the intact acromioclavicular joint: a cadaveric study.

BACKGROUND: The aim of this study was to find reliable anatomic landmarks of the normal acromioclavicular joint (ACJ) that could enable the precise evaluation of the horizontal displacement of the clavicle after dislocation. The hypothesis was that the anterior borders of the acromion and the clavicle are always aligned in intact ACJs. MATERIALS AND METHODS: In 30 cadaveric specimens, the anterior and posterior borders of the ACJ's articular facets and the most prominent anterior and posterior bony landmarks of the acromion and the clavicle were identified. The anterior and posterior overhang of the acromion and the clavicle was measured in relation to the borders of the articular facets. Therefore, the possible anterior and posterior alignment of the ACJ was evaluated. RESULTS: Anteriorly, only 18 ACJs (60%) were aligned whereas 7 (24%) had major overhang of the acromion and 3 (10%) had major overhang of the clavicle. Similarly, 18 cases (60%) were posteriorly aligned, whereas 6 (20%) had major clavicular overhang and 4 (14%) had major overhang of the acromion. In 78% of these cases, the ACJ was aligned as well anteriorly as posteriorly (P < .001). Finally, the larger the width of the acromion (P = .032) or the clavicle (P = .049), the better the posterior joint alignment. CONCLUSION: Our hypothesis was not verified. The acromion and clavicle are not perfectly aligned in a significant number of specimens with intact ACJs (40% of cases). The most reliable landmarks remain their articular facets.