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.

[Association of morphological variables of acromion type with rotator cuff lesions by nuclear magnetic resonance]. / Asociación de variables morfológicas de tipo de acromion con lesiones del manguito rotador por resonancia magnética nuclear.

INTRODUCTION: the acromion is a small portion of the scapula that extends towards the anterior region from the spine of the scapula. Traditionally, the acromion is classified by the shape of its inferior surface in a sagittal plane. Acromial morphology has been found to be related to rotator cuff injury. OBJECTIVE: to determine the association between the type of acromion with a higher incidence of rotator cuff rupture. Study population: patients who come to the Traumatology and Orthopedics Service of a third level hospital at Monterrey, Mexico, due to a painful shoulder and who have undergone a simple magnetic resonance of the shoulder. MATERIAL AND METHODS: a cross-sectional, retrospective and descriptive study was carried out, in which 273 magnetic resonance studies were reviewed in patients who met the inclusion criteria. The type of acromion was reported according to the morphological classification in type I to IV and the state of the rotator cuff: without rupture, partial rupture or complete rupture, making a comparison between right and left shoulder. RESULTS: in this study we found a value of p = 0.473 which concludes that there is no relation between the type of acromion and the injury of the rotator cuff. CONCLUSION: in the present study, unlike what has been published in the literature, it was found that type II acromion was the one that was associated in most cases with a rotator cuff tear.

INTRODUCCIÓN: el acromion es una pequeña porción de la escápula que se extiende hacia la región anterior desde la espina de la escápula. Tradicionalmente se clasifica al acromion por la forma de su superficie inferior en un plano sagital. Se ha encontrado que la morfología acromial está rela­cionada con la lesión del manguito rotador. OBJETIVO: determinar la asociación entre el tipo de acromion con una mayor incidencia de ruptura de manguito rotador. Población de estudio: pacientes que acudan al Servicio de Traumatología y Ortopedia de un hospital privado de tercer nivel en la ciudad de Monterrey por hombro doloroso y a los cuales se les haya realizado una resonancia magnética simple de hombro. MATERIAL Y MÉTODOS: se realizó un estudio de tipo transversal, retrospectivo y descriptivo, en el cual se revisaron 273 estudios de resonancia magnética en pacientes que cumplieran los criterios de inclusión. Se reportó el tipo de acromion según la clasificación morfológica en tipo I a IV y el estado del manguito rotador: sin ruptura, ruptura parcial o ruptura completa, haciendo una comparación entre hombro derecho e izquierdo. RESULTADOS: se obtuvo un valor de p = 0.473 por lo que se concluye que no existe una asociación entre el tipo de acromion y el estado del manguito rotador. CONCLUSIÓN: en el presente estudio, a diferencia de lo publicado en la literatura, se obtuvo que el acromion tipo II fue al que se asoció la mayoría de los casos con ruptura del manguito rotador.

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.

Are differences in shoulder morphology and hand dominance risk factors for rotator cuff tears?

OBJECTIVE: The purpose of this study was to evaluate whether there was a difference in shoulder morphology and hand dominance between a healthy shoulder and a shoulder with rotator cuff tear (RCT) in the same patient. PATIENTS AND METHODS: Between 2015 and 2020, 120 shoulders from 60 patients with complete RCT and contralateral intact rotator cuffs were enrolled in this retrospective analysis. Physical examinations, shoulder radiographs, and magnetic resonance imaging (MRI) pictures of the patients were reviewed. On radiographs, the AT, CSA, LAA, and AI values were compared between shoulders with complete RCT and contralateral healthy shoulders from the same individuals. Additionally, the association between hand dominance and RCT was evaluated. RESULTS: This study enrolled 60 patients. 59.17% of the participants are female, and 40.83% are male. The mean age of the patients was 54.5±7.1 years. There were statistically significant differences in AI, CSA, and LAA measurements between the study group (RCT group) and the control group. There was no significant difference in AT between the two groups. CONCLUSIONS: There are morphological differences between a healthy shoulder and a shoulder with an RCT in the same patient, and these differences (LAA/CSA/AI/AT) may have an effect on the prevalence of RCT.

Acromion types and morphometric evaluation of painful shoulders.

BACKGROUND: Due to its many variations, the scapula is among the most frequently examined bones. Especially the acromion can be of different shapes and sizes. Measurements of the morphometric structures in the shoulder joint make it easier to explain the cause of the various shoulder problems. The objective of this study is putting emphasis on the importance of acromion types, os acromiale presence and acromial morphometric measurements in the aetiology and diagnosis of shoulder pain. MATERIALS AND METHODS: A retrospective study, based on 100 patients of both genders who presented with the complaints of shoulder pain and underwent magnetic resonance imaging, was conducted. Within this scope, types of acromion, slope of acromion, length of acromion, length of coracoid process, the distance between acromion and coracoid process, lateral acromial angle (LAA), critical shoulder angle (CSA), acromial index (AI) and acromiohumeral distance were measured. The data were analysed considering the gender and acromion types and the presence of os acromiale is investigated. RESULTS: The most common acromion was type II (curved) (frequency rate 62%) while the rate of type I (flat) and type III (hooked) acromions were 21% and 17%, respectively. The length of acromion and coracoid process were found to be significantly longer in males, while no significant difference between genders in terms of the distance between acromion and coracoid process were observed. Furthermore, while negative correlation between LAA and AI as well as LAA and CSA were observed; positive correlation between AI and CSA was found. In addition, there was negative correlation between slope of acromion and acromiohumeral distance. Besides, acromiohumeral distance was significantly higher in males. Regarding the presence of os acromiale, it was observed in 3 women out of 59 and 2 men out of 41, which indicated no significant difference between genders. CONCLUSIONS: It is evaluated that the morphometric measurement is of importance in contributing clinically in distinguishing the problems that may occur according to gender and acromion types.

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.

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.

The prevalence of acromial spurs in relation to study type and specimens examined

Advanced cases of subacromial impingement syndrome usually present with acromial spurs. However, previous studies have reported variations in the prevalence of acromial spurs in shoulders with or without subacromial impingement syndrome as well as with age, sex, and side. Therefore, this study is aimed at investigating the prevalence of acromial spurs in cadaveric shoulders and reviewing the factors leading to the reported variable frequencies. The study examined 220 cadaveric shoulders (110 male and 110 female), with a median age of 82 years (with a range of 53 to 102 years). In 155 shoulders, the rotator cuff tendons were evaluated for tears; acromial spurs were observed in 95 shoulders (43%). No significant association was observed between the prevalence of acromial spurs and sex or side. However, a significant prevalence of spurs (57%) was observed in the oldest-old group, aged ≥ 85 years. Those with acromial spurs also tended to be older (84 years) than those without spurs (81 years). A significant difference in the prevalence of acromial spurs was observed in shoulders with rotator cuff tears compared to those without them: 80% compared to 20%, respectively. Analysis showed a significant number of acromial spurs in shoulders with full-thickness tears (46%) and partial tears (34%). A significant prevalence of acromial spurs was found in shoulders with rotator cuff tears, as well as in aged shoulders. In relevant literature, the prevalence of acromial spurs varies with the type of study undertaken, age, prevalence of rotator cuff tears, and type of radiograph examined

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Influence of Acromial Morphologic Characteristics and Acromioclavicular Arthrosis on the Effect of Platelet-Rich Plasma on Partial Tears of the Supraspinatus Tendon.

OBJECTIVE. The purposes of this study were to determine the medium-term effect of ultrasound-guided infiltration of platelet-rich plasma (PRP) on partial tears of the supraspinatus tendon (SST) and to identify prognostic indicators of an unfavorable outcome. SUBJECTS AND METHODS. Over a period of 4 years, patients with a partial SST tear smaller than 1.5 cm referred for ultrasound-guided PRP infiltration (1 mL) for shoulder pain lasting more than 3 months were recruited consecutively. MRI was used to analyze the type of acromion and presence of acromioclavicular (AC) arthrosis. Primary (size of the tear and associated bursitis) and secondary (mobility and pain) results were collected at 3 months. RESULTS. The study included 128 patients (66 men, 62 women; mean age, 48.3 years; range, 20-59 years). At 3 months, favorable evolution of the tear repair was recorded in 71.1% (91/128) of patients and resolution of bursitis in 66.7% (42/63). Changes in tear size had large effect sizes (Cohen d ≥ 1.16), as did pain and shoulder mobility (Cohen d ≥ 0.95). The strongest predictors of unfavorable evolution of tear and bursitis were type 3 acromion and types 1 and 2 acromion with AC arthrosis (p < 0.001; ß = 20.412). CONCLUSION. Ultrasound-guided PRP infiltration of partial tears of the SST relieves pain and improves shoulder mobility, but its effect on the size of the tear is influenced by the morphologic characteristics of the acromion and the presence of AC arthrosis. The effect of PRP is insufficient in patients with a type 3 acromion or severe AC arthrosis.

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.

Subacromial impingement anatomy and its association with rotator cuff pathology in women: radiograph and MRI correlation, a retrospective evaluation.

OBJECTIVE: To evaluate the relationships between acromial anatomy and developmental alterations with rotator cuff tears in female patients and compare these parameters on radiographs and corresponding MRIs along with inter-reader performance. MATERIALS AND METHODS: Patient demographics, symptoms, and acromial characteristics on radiograph (acromial index, lateral acromion angle, subacromial space on AP and Y- views, acromial anterior and lateral downsloping) and MRI (shape, slope, spur, osteoarthrosis, os acromiale) were recorded. Radiographic and MRI findings were compared and correlated with rotator cuff pathology on MRI. Inter-reader analysis was performed. RESULTS: A total of 140 MRIs from 137 female patients were included. No significant correlation (p > 0.05) existed between acromial parameters and rotator cuff tears, except for a smaller subacromial space on the Y view and spurs correlated with subscapularis tendon tear (p = 0.02, p = 0.04). The presence of lateral downsloping on MRI correlated with a smaller lateral acromion angle (p = 0.0002) and the presence of lateral downsloping on radiography (p = 0.0015). Inter-reader agreements were good to excellent (ICC: 0.65-0.89). CONCLUSION: Subacromial impingement anatomy characteristics have no significant associations with supraspinatus or infraspinatus tears in symptomatic women. Among different measures, supine MRI can be reliably used to identify lateral downsloping of the acromion.

The effect of glenohumeral plane of elevation on supraspinatus subacromial proximity.

Shoulder pain is a common clinical problem affecting most individuals in their lifetime. Despite the high prevalence of rotator cuff pathology in these individuals, the pathogenesis of rotator cuff disease remains unclear. Position and motion related mechanisms of rotator cuff disease are often proposed, but poorly understood. The purpose of this study was to determine the impact of systematically altering glenohumeral plane on subacromial proximities across arm elevation as measures of tendon compression risk. Three-dimensional models of the humerus, scapula, coracoacromial ligament, and supraspinatus were reconstructed from MRIs in 20 subjects. Glenohumeral elevation was imposed on the humeral and supraspinatus tendon models for three glenohumeral planes, which were chosen to represent flexion, scapular plane abduction, and abduction based on average values from a previous study of asymptomatic individuals. Subacromial proximity was quantified as the minimum distance between the supraspinatus tendon and coracoacromial arch (acromion and coracoacromial ligament), the surface area of the supraspinatus tendon within 2 mm proximity to the coracoacromial arch, and the volume of intersection between the supraspinatus tendon and coracoacromial arch. The lowest modeled subacromial supraspinatus compression measures occurred during flexion at lower angles of elevation. This finding was consistent across all three measures of subacromial proximity. Knowledge of this range of reduced risk may be useful to inform future studies related to patient education and ergonomic design to prevent the development of shoulder pain and dysfunction.

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.