Acromion Type Research Articles

Interobserver reliability of shoulder radiographic findings and correlation to MRI: a preliminary case series.

The aim of this study was to evaluate the interobserver reliability of measurements of the Acromiohumeral Distance (AHD) first described by Golding et al., the Critical Shoulder Angle (CSA), the Acromion Index with Glenoid Humeral (GH) and Glenoid Acromial (GA) distances, following the measuring method by Nyffeler et al., the Lateral Acromion Angle (LAA), as well as the morphology of the acromion according to Bigliani and the humeral head position according to Maloney in X-rays and MRI. Furthermore, the study assessed the correlation of measurement results in X-ray with those in MRI for AHD, CSA, GA, GH, AI, and LAA. A total of 187 patients who underwent shoulder joint X-ray and MRI examinations from 09/2016 to 05/2023 were included in the study. Patients with poor imaging quality, arthrosis or radical prior surgeries, like shoulder prosthetic surgery, status post humerus fractures, that have undergone surgery and therefore changed the anatomical features were excluded, what lead to a total study population of 78. X-ray measurements were performed by two observers in the true anteroposterior view, so that the humeral head and the glenoid are shown without overlap, providing a clear view into the joint space. MRI measurements were performed in oblique coronal MRI slices, using the most accurately depicted glenoid surface as a landmark. Interobserver measurement results showed a significance with p < 0.001 for the assessment of acromion type according to Bigliani, humeral head offset assessment according to Maloney, and AHD. No significance was found for interobserver reliability in measuring LAA. Additionally, there was a high correlation of measurement results in X-ray with measurements in MRI for, CSA, GH/GA, and consequently AI, a good correlation for AHD but no correlation could be shown for LAA. These findings provide valuable insights into the robustness of radiological parameters for evaluating shoulder pathology, offering promising prospects for clinical applications and further research. Nevertheless, the specific methodological considerations and patient characteristics should be taken into account when interpreting the results to ensure their accurate application in clinical practice.

Radiographic findings in patients suspected of subacromial impingement syndrome: prevalence and reliability

ObjectiveAims were to (i) report prevalence and (ii) evaluate reliability of the radiographic findings in examinations of patients suspected of subacromial impingement syndrome (SIS), performed before a patient’s first consultation at orthopaedic department.Materials and methodsThis cross-sectional study examined radiographs from 850 patients, age 18 to 63 years, referred to orthopaedic clinic on suspicion of SIS. Prevalence (%) of radiographic findings were registered. Inter- and intrarater reliability was analysed using expected and observed agreement (%), kappa coefficients, Bland–Altman plots, or intraclass coefficients.ResultsA total of 850 patients with a mean age of 48.2 years (SD = 8.8) were included. Prevalence of the radiographic findings was as follows: calcification 24.4%, Bigliani type III (hooked) acromion 15.8%, lateral/medial acromial spurs 11.1%/6.6%, acromioclavicular osteoarthritis 12.0%, and Bankart/Hill-Sachs lesions 7.1%. Inter- and intrarater Kappa values for most radiographic findings ranged between 0.40 and 0.89; highest values for the presence of calcification (0.85 and 0.89) and acromion type (0.63 and 0.66). The inter- and intrarater intraclass coefficients ranged between 0.41 and 0.83; highest values for acromial tilt (0.79 and 0.83) and calcification area (0.69 and 0.81).ConclusionCalcification, Bigliani type III (hooked) acromion, and acromioclavicular osteoarthritis were prevalent findings among patients seen in orthopaedic departments on suspicion of SIS. Spurs and Bankart/Hill-Sachs lesions were less common. Optimal reliabilities were found for the presence of calcification, calcification area, and acromial tilt. Calcification qualities, acromion type, lateral spur, and acromioclavicular osteoarthritis showed suboptimal reliabilities. Newer architectural measures (acromion index and lateral acromial angle) performed well with respect to reliability.

Distribution and analysis of subacromial spurs and the relationship with acromial classification and angle in healthy individuals.

Subacromial spurs are considered the one of the pathology underlying shoulder impingement syndrome. Furthermore, few studies have focused on the morphology of the subacromial spurs in normal Chinese people. This study aimed to study the spur distribution and to illustrate the morphology of spurs, which may help guide the extent of acromioplasty. A total of 93 normal individuals were enrolled, and both shoulders of all enrolled individuals were analyzed. The subjects were divided and classified into three different groups by ages: group I = 18-40 years, group II = 41-60 years, and group III ≥ 61 years. The osteophyte distribution, osteophyte area, subacromial surface area and osteophyte area/subacromial surface area ratio were measured and illustrated using Mimics and 3-matic software. The shape of the acromion was classified according to the Bigliani and Morrison classification system. The acromial angle was also classified. Then, the relationship between osteophytes, acromial classification and acromial angle was analyzed. Type II (curved shape) was the most common type of acromion, and the hooked shape was a rare form. A significant increase in the left subacromial surface area in males was observed in group III compared with group I (P < 0.001) and group II (P = 0.004). The total spur/subacromial area ratio was significantly higher in group II than I. An obvious increase in the right subacromial area was observed in group III compared with group I (P = 0.004). Furthermore, there was a significant increase in the right spur area (P = 0.021) and total spur/subacromial area ratio (P = 0.006) in females in group II compared with group I. Fewer spurs were observed on the left than on the right side (p = 0.0482). One spur was most common among type II acromions (29/36) (80.56%) on the left side and the right side (34/52, 65.38%). Spurs osteophytes are mainly distributed with an irregular shape and mostly run through the medial and lateral sides of the subacromial surface in normal subjects. The characteristics of subacromial spurs are so diverse that a surgeon must conduct subacromial decompression completely based on the morphology of individual spurs.

Comparison of the Post Treatment Outcomes of a Conservative Physiotherapy Protocol for Subacromial Impingement Syndrome in Terms of Acromion Morphology

Objective: The present study aimed to compare the results of a conservative physiotherapy (CP) protocol for subacromial impingement syndrome (SIS) in terms of the morphological types of acromion. Methods: Fifty patients participated in the present study, and they were divided into 3 groups according to the acromion morphology types. A 8-week CP (4-week treatment period at the clinic and, in addition, an exercise program at home for 4 weeks) was applied to all patients. The patients were evaluated in terms of pain (at rest and activity) by the Visual Analog Scale, range of motion (ROM), joint position sense (laser pointer), muscle strength (digital dinamometer), and functionality (the Shoulder Pain and Disability Index, SPADI) before and after the treatment. Result: In the pre- and post-treatment changes (delta), the shoulder flexion angle increased less in the type 3 group than in the type 1 and type 2 groups (p&lt;0.05). In the shoulder abduction angle, there was a similar increase in the type 3 group compared to the type 2 group, while there was less increase in the type 1 group (p&lt;0.05). It was determined that there was more deviation in the change value of shoulder abduction position sense in the type 3 group compared to the other groups (p&lt;0.05). There was no difference between the groups in the change values of pain, muscle strength, or the SPADI score (p &gt; 0.05). Conclusion: Type 3 acromion may have a handicap in improving shoulder flexion and abduction ROM and shoulder abduction position compared to other types.

Rotator Cuff Repair With or Without Acromioplasty: A Systematic Review of Randomized Controlled Trials With Outcomes Based on Acromial Type.

It is unclear whether the use of concomitant acromioplasty during rotator cuff repair (RCR) improves clinical outcomes and whether the outcomes are affected by acromial type. To perform a systematic review of randomized controlled trials comparing clinical outcomes of RCR with and without acromioplasty, with a subanalysis of outcomes based on acromial type. Systematic review; Level of evidence, 2. A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching PubMed, the Cochrane Library, and Embase to identify randomized controlled trials that directly compared outcomes between RCR with versus without acromioplasty. A subanalysis was performed on the studies that provided outcomes based on acromial type. The search phrase used was rotator cuff repair (acromioplasty OR subacromial decompression) randomized. Patients were evaluated based on retear rate, reoperation rate, and patient-reported outcomes (PROs). Application of inclusion criteria yielded 5 studies (2 studies were level 1, and 3 studies were level 2) including a total of 409 patients, with 211 patients undergoing RCR alone (group A) and 198 patients undergoing RCR with acromioplasty (group B). The mean patient age was 58.5 and 58.3 years in groups A and B, respectively. The mean follow-up time was 52.9 months, and the overall percentage of male patients was 54.1%. The rotator cuff tear size was 20.7 mm and 19.8 mm for groups A and B, respectively. No significant differences were found between groups for any of the PROs at final follow-up. Overall retear rates did not significantly differ between groups based on acromial type. Between 2 studies that measured reoperation rate, a significantly higher reoperation rate was found for the nonacromioplasty group (15%) versus the acromioplasty group (4.1%) (P = .031). One of these studies found that 5 of 9 patients (56%) with a type III acromion in the nonacromioplasty group underwent reoperation compared with 0 of 4 patients with a type III acromion in the acromioplasty group. There is some evidence that acromioplasty during RCR reduces the risk for later reoperation. This may be particularly true for patients with type III acromions, although further studies with larger sample sizes are needed to corroborate these data.

Biomechanical comparison of single versus double plate osteosynthesis in acromion type III fractures.

One of complications of the reverse shoulder arthroplasty is acromion fractures, and its therapy is controversial. The aim of the study was to investigate the double-plate osteosynthesis for these fractures. An acromion type III fracture according to classification of Levy was simulated in 16 human shoulder cadavers, and the specimens were randomly divided into two groups. Single-plate osteosynthesis was performed in the first group (locking compression plate) and double-plate osteosynthesis (locking compression plate and one-third tubular locking plate) in the second group. Biomechanical testing included cycling load and load at failure on a material testing machine. During the test, the translation was measured using an optical tracking system. The load at failure for the single-plate osteosynthesis was 167 N and for the double-osteosynthesis 233.7 N (P = 0.328). The average translation was 11.1 mm for the single-plate osteosynthesis and 16.4 mm for the double-plate osteosynthesis (P = 0.753). The resulting stiffness resulted in 74.7 N/mm for the single-plate osteosynthesis and 327.9 N/mm for the double-plate osteosynthesis (P = 0.141). Results of the biomechanical study showed that double-plate osteosynthesis had biomechanical properties similar to those of single-plate osteosynthesis for an acromion type III fracture at time point zero. The missing advantages of double-plate osteosynthesis can be explained by the choice of plate configuration.

Does Morphology of the Shoulder Joint Play a Role in the Etiology of Rotator Cuff Tear?

The etiology of rotator cuff tears (RCTs) have been investigated for years and many underlying causes have been identified. Shoulder joint morphology is one of the extrinsic causes of RCTs. Morphometric measurements on MRI sections determined which parameters are an important indicator of RCT in patients with shoulder pain. The aim of this study was to determine the risk factors in the etiology of RCTs by evaluating the shoulder joint morphology with the help of previously defined radiological parameters. Between January 2019-December 2020, 408 patients (40-70 years old) who underwent shoulder MRI and met the criteria were included in the study. There were 202 patients in the RCT group and 206 patients in the control group. Acromion type, acromial index (AI), critical shoulder angle (CSA), acromiohumeral distance (AHD), lateral acromial angle (LAA), acromial angulation (AA), acromion-greater tuberosity impingement index (ATI), and glenoid version angle (GVA) were measured from the MRI images of the patients. AI (0.64 vs. 0.60, p = 0.003) CSA (35.3° vs. 32.4°, p = 0.004), ATI (0.91 vs. 0.83, P < 0.001), and AA (13.6° vs. 11.9°, p = 0.011) values were higher in the RCT group than in the control group and the difference was significant. AHD (8.1 mm vs. 9.9 mm, P < 0.001), LAA (77.2° vs. 80.9°, p = 0.004) and GVA (-3.9° vs. -2.5°, P < 0.001) values were lower in the RCT group than in the control group, and again the difference was significant. According to the receiver operating characteristic curve analysis, the cutoff values were 0.623 for AI and 0.860 for ATI. Acromion type, AI, CSA, AHD, LAA, AA, ATI, and GVA are suitable radiological parameters to evaluate shoulder joint morphology. High AI, CSA, AA, ATI, GVA and low AHD and LAA are risk factors for RCT.

Evaluation of the acromion variants in MRI and their association with rotator cuff injuries in non-traumatic patients

PurposeUnderstanding demographic and MRI parameters with determinant role in rotator cuff tearing (RCT) is required to predict outcomes and select more appropriate treatment in patients with non-traumatic shoulder pain. This study aimed to survey the association of rotator cuff tears with these factors. MethodsWe performed this cross-sectional study on patients referred to Kashani Hospital with non-traumatic shoulder pain suspected of rotator cuff injuries from April 2020 to February 2021. We obtained their demographic data and MRI from electronic hospital records. After that, two radiologists reviewed MRI and recorded data. We employed the SPSS 23 software to organize the obtained results and statistical evaluations. Results371 subjects, with the age of 48.61 ± 14.89 years, were included in our study, and 50% of them were male. The flat and down-sloping acromion and partial tearing of the supra and infraspinatus tendons were more frequent than the others. Gender could not consider as a determinant factor for the severity of tendon injuries, acromion types and variants. The relation of age to acromion morphology and the tendinopathy severity was significant. Remarkably, down-sloping acromion was higher at all the acromion shapes; however, it makes no difference in the level of supra and infraspinatus involvement. Moreover, we found that partial tearing was higher in all acromion types, except concave. This distribution was significant only for supraspinatus tears. ConclusionThe clinical decision is the most important step in patients with RCT and MRI prognostic factors, which are helpful to improve the management of the cases. RCT in older patients and down-slope acromion was more severe than the others. According to the previous studies, acromion morphology (as an important determinant factor) in RCT could be influenced by age, as well.

Injection of autologous conditioned plasma combined with a collagen scaffold may improve the clinical outcome in shoulder impingement syndrome: a prospective study

BackgroundShoulder impingement syndrome (SIS) is one of the most common diseases of the shoulder and can be addressed with various therapeutic concepts. Orthobiological agents such as platelet rich plasma with a low side effect rate gain importance in the conservative treatment of SIS. Currently, the knowledge about success rate influencing factors, such as the growth factors (GF) concentration or acromion type, is limited. The aim of this study was to analyze the clinical outcome in the therapy of external SIS using autologous conditioned plasma combined with recombinant human collagen scaffold (ACP/STR) injection in comparison with a corticosteroid-local anesthetic (CSA) injection. Additionally, the influence of potential limiting factors such as GF concentration, age and acromial morphology was proved.Materials and methodsThis prospective pseudo-randomized trial recruited 58 patients with external SIS who received an ultrasound-guided subacromial injection either an ACP/STR or a CSA followed by physical therapy. Follow-up (FU) was performed at 6 weeks, 3 and 6 months. The outcome was assessed with Constant–Murley score, disability of arm, shoulder and hand score and simple shoulder test. The concentration of GF was measured using ELISA.ResultsDuring the FU, the improvement of outcome measures was observed with no differences between both groups. Shoulder force was significantly increased in the ACP/STR group (p < 0.01). We found no correlation between the amount of GF and age or gender in the ACP/STR patients. An acromion Bigliani type III predisposes for therapy failure (p < 0.001, OR = 56) in both treatment groups.ConclusionsPatients with SIS benefit regarding to PROMs after both ACP/STR and CSA injection and physical therapy. Patients who received ACP/STR obtained superior improvement in force. The quantity of GF did not vary depending on the age, so that ACP/STR can be a treatment option for SIS in elderly patients with multimorbidity. The presence of an acromion type III seems to be a predictive factor for limited effectivity of injections in the clinical management of SIS.

Evaluation of the prognostic value of the anatomical characteristics of the bony structures in the shoulder in bursal-sided partial-thickness rotator cuff tears.

In recent studies, individual scapular anatomy has been found to be related to degenerative full-thickness rotator cuff tears. However, research on the relationship between the anatomical characteristics of shoulder radiographs and bursal-sided partial-thickness rotator cuff tears (PTRCTs) is limited, and the risk factors for this pathology still need to be determined. The bursal-sided PTRCTs group included 102 patients without a history of shoulder trauma who underwent arthroscopy between January 2021 and October 2022. A total of 102 demographically matched outpatients with intact rotator cuffs were selected as the control group. Radiographs were used to measure the lateral acromial angle (LAA), critical shoulder angle (CSA), greater tuberosity angle (GTA), β-angle, acromion index (AI), acromiohumeral distance (AHD), acromial tilt (AT), acromial slope (AS), acromial type, and acromial spur by two independent observers. Multivariate analyses of these data were used to identify potential risk factors for bursal-sided PTRCTs. Receiver operating characteristic (ROC) analysis was performed to assess the sensitivity and specificity of CSA, GTA, and AI for this type of pathology. The β-angle, AHD, AS and acromion type showed no difference between bursal-sided PTRCTs and controls (p = 0.009, 0.200, 0.747 and 0.078, respectively). CSA, GTA and AI were significantly higher in bursal-sided PTRCTs (p < 0.001). LAA, β-angle and AT were significantly lower in bursal-sided PTRCTs. Multivariate logistic regression analysis demonstrated significant correlations between the acromial spur (p = 0.024), GTA (p = 0.004), CSA (p = 0.003) and AI (p = 0.048) and bursal-sided PTRCTs. The areas under the ROC curves for AI, CSA, and GTA were 0.655 (95% CI 0.580-0.729), 0.714 (95% CI 0.644-0.784), and 0.695 (95% CI 0.622-0.767), respectively. Acromial spur, GTA, CSA, and AI were independent risk factors for bursal-sided PTRCTs. Furthermore, CSA was the most powerful predictor of bursal-sided PTRCTs compared to GTA and AI.

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

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. 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. 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 ± 1.56mm in the study group and 9.2 ± 1.3mm 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). 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.

Anatomy features of the shoulder joint in asymptomatic chinese Han adults

BackgroundTo evaluate the shoulder anatomical characteristics in asymptomatic Chinese adults.MethodsThe prospective study enrolled individuals without shoulder pain at Beijing Tiantan Hospital Affiliated to Capital Medical University between January 2019 and January 2020. Six radiographic parameters were measured and analyzed, including glenoid plane to the acromion (GA), glenoid plane to the lateral aspect of the humeral head (GH), acromion index (AI), lateral acromial angle (LAA), acromion-humeral interval (AHI), and critical shoulder angle (CSA).Results103 participants (51 males and 52 females) were enrolled. The mean values of GA, GH, AI, CSA, LAA, and AHI were 32.88 ± 5.68 mm, 47.16 ± 4.82 mm, 0.70 ± 0.11, 37.45 ± 6.00°, 6.32 ± 3.99°, and 9.611.86 mm, respectively. Females had lower GA (30.78 ± 5.06 vs. 35.01 ± 5.51 mm, P < 0.001) and GH (44.28 ± 3.67 vs. 50.11 ± 4.02 mm, P < 0.001) than males and LAA was significantly smaller in the Bigliani flat type compared with the curved type and the hooked type (5.07 ± 2.31° vs 12.33 ± 5.46°vs 10.00 ± 3.37, P = 0.001).ConclusionsFemales had lower GA and GH than males in asymptomatic Chinese Han adults. Asymptomatic Chinese Han subjects with Bigliani flat type had lower LAA. CSA appears lager in Chinese Han individuals. Curve type of acromion performed lager LAA. The results may help establish an anatomical model of the shoulder joint and elucidate the anatomy features of the shoulder joint in asymptomatic Chinese Han adults.

Correlation of some anatomical angles of the shoulder with rotator cuff syndrome

Background: Shoulder movement occurs through the coordinated work of muscles, tendons, ligaments, and bones, primarily that affect the glenohumeral joint. Some distances and the angles between the bones forming this joint are important in shoulder pathologies. In this study, we aimed to determine the evaluation of nine different radiological parameters related to acromion and humerus in rotator cuff syndrome and control group patients. Materials and Methods: A total of 400 patients’ routine clinic radiographs were retrospectively assessed, which have rotator cuff syndrome (n = 210), and control group (n = 190). We measured the critical shoulder angle (CSA), distance of glenoid-acromion (GA), distance of glenoid-humeral head (GH), acromial index, lateral acromial angle (LAA), total shoulder arthroplasty angle (TSA), reverse shoulder arthroplasty angle (RSA), Point T represents the superior border of the glenoid cavity, Point S represents the inferior border of the glenoid cavity, point R represents the intersection of the supraspinatus fossa line with the glenoid surface. RST angle, and greater tuberosity angle (GTA) angle. We determined the type of acromion. Results: We determined that the GH, TSA, RST, and GTA were significantly different between rotator cuff syndrome and control group patients. When we evaluated the acromion type, Type 2 was the most common type. Different from the literature, when we evaluated the relationship between acromion types and angles, we determined that LAA, GA, and TSA parameters were significantly different between acromion types. Conclusions: In this study, we determined the importance of measurements and angles in rotator cuff syndrome. We think that the relationship between acromion types and parameters can contribute to the literature. Moreover, we believe that our study will contribute to the literature in terms of gathering many angles that are important in shoulder pathologies in a single study.

Acromial Morphology and Its Relation to the Glenoid Is Associated with Different Partial Rotator Cuff Tear Patterns

The pathogenesis of subacromial impingement syndrome is controversially discussed. Assuming that bursal sided partial tears of the supraspinatus tendons are rather the result of a direct subacromial impact, the question arises whether there is a morphological risk configuration of the acromion and its spatial relation to the glenoid. Patients who underwent arthroscopic repair of either a partial articular supraspinatus tendon avulsion (PASTA) or bursal-sided supraspinatus tear (BURSA) were retrospectively allocated to two groups. Various previously described and new omometric parameters on standard anteroposterior and axial shoulder radiographs were analyzed. We hypothesized that acromial shape and its spatial relation to the glenoid may predispose to a specific partial supraspinatus tendon tear pattern. The measurements included the critical shoulder angle (CSA), the acromion index (AI), Bigliani acromial type and the new short sclerotic line, acromioclavicular offset angle (ACOA), and AC offset. The ratio length/width of acromion and the medial acromial offset were measured on axial radiographs. A total of 73 patients were allocated to either PASTA (n = 45) or BURSA (n = 28). The short sclerotic line showed a statistically significant difference between PASTA and BURSA (16.2 mm versus 13.1 mm, p = 0.008). The ratio acromial width/length was statistically significant (p = 0.021), with BURSA having slightly greater acromial length (59 vs. 56 mm). The mean acromial offset was 42.9 mm for BURSA vs. 37.7 mm for PASTA (p = 0.021). ACOA and AC offset were both higher for BURSA, without reaching statistical significance. The CSA did not differ significantly between PASTA and BURSA (33.73° vs. 34.56°, p = 0.062). The results revealed an association between a narrow acromial morphology, increased medial offset of the acromion in relation to the glenoid, and the presence of a short sclerotic line in the anteroposterior radiograph in bursal-sided tears of the supraspinatus tendon. Assuming that bursal-sided tears are rather the result of a direct conflict of the tendon with the undersurface of the acromion, this small subgroup of patients presenting with impingement syndrome might benefit from removing a harming acromial spur.

Acromion types and morphometric evaluation of painful shoulders.

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. 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. 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. 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.

The correlation between acromial osteolysis and acromion types in the treatment of acromioclavicular joint dislocation with hook plate.

This study aimed to radiologically evaluate the effect of hook plates used in the treatment of acromioclavicular joint (ACJ) dislocations on the development of subacromial osteolysis (SAO) according to acromion types. A total of 43 patients with mean age of 38.5 (19-77) years who were diagnosed with AC dislocation and applied neutral clavicular hook plate between 2013 and 2020 were retrospectively evaluated. Acromion types were determined by measuring acromion slope angle on lateral shoulder radiography and 3-dimensional (D)-CT of the patients. Presence of SAO was classified according to the severity of erosion in the subacromial region (grade I: minimal osteolysis, grade II: subacromial erosion <2 mm, grade III: subacromial erosion >2 mm, grade IV: cut-through of the acromion) on postoperative 3D - CT and correlation with acromion types was analyzed. Incidence of SAO was significantly higher among type 1 acromion compared to type 2 and type 3 acromion (P = .003). While osteolysis was observed in 21 patients, no osteolysis was observed in 22 patients. Osteolysis occurred in all patients with type 1 acromion, 7 patients with type 2 acromion, and 5 patients with type 3 acromion. Since the hook tip in the sagittal plane passes posterior to the center of the acromion and the concavity of the subacromial surface is inadequate in the type 1 acromion, we believe that the increased pressure applied by the hook tip on the subacromial cartilage increases the risk of SAO. We predict that the use of hook plates with an angle of 15-20 degrees, similar to the patient's AC angle, rather than neutral hook plate, will reduce the risk of osteolysis in patients with type 1 acromion.

Clinical application of acromion radiological classification in diagnosis and treatment of rotator cuff injury

To develop a new classification of acromion based on the subacromial impingement theory and the Rockwood tilt view. And explore the application value of the new classification in the diagnosis and treatment of rotator cuff tear. The clinical data of 101 patients underwent shoulder arthroscopic surgery for impingement syndrome or rotator cuff tear from January to December 2017 were retrospectively analyzed. There were 34 males and 67 females, aged from 34 to 76 years with an average of (56.31±9.63) years old, course of disease from 2 to 12 months with average of 6 months. Preoperative radiographs of the routine anteroposterior view, Rockwood tilt view and the supraspinatus outlet view were obtained. Based on the subacromial impingement theory and Rockwood radiographs, the morphology of the acromion can be divided into three types:typeⅠ(flat type), typeⅡ(bump type), and type Ⅲ (impingement type). Two observers classified 101 shoulder Rockwood radiographs according to the new classification method and the supraspinatus Outlet radiographs according to the traditional acromial morphological classification method. Supraspinatus tendon injuries were classified into no tear, partial-thickness tear, and full-thickness tear according to the arthroscopic findings. Concordance test (Kappa value) between the inter-observer and intra-observer was carried out for the new classification method and the traditional classification method respectively. The rank sum test was used to compare the mean acromiohumeral distance(AHD) of the three acromion forms in the new acromion classification method. Spearman rank correlation test and Gamma method were used to analyze the correlation between the new acromion classification method and the degree of supraspinatus tendon tear. The inter-observer consistency analysis of the new classification system was significantly better than that of the traditional classification (0.827 vs 0.278), the intra-observer consistency analysis of the new classification system were also significantly better than that of the traditional classification (0.921 vs 0.448, 0.890 vs 0.539). There was no statistical significance in the AHD among three types of the new classification(H=2.186, P>0.05). In all 101 patients, the highest proportion of impingement type acromion was 45.5% (46 cases), followed by bump type acromion was 36.6% (37 cases), and flat type acromion was 17.8% (18 cases). The incidence of supraspinatus tendon tear in the patients with impingement type acromion was significantly higher than that of the other two types of acromion, there was a spearman rank correlation between the new acromion type and the degree of the supraspinatus tendon tear(rs=0.719, P<0.001). Rockwood radiographs of the shoulder can well display the anterolateral osteophytes of the acromion. The new acromion classification method based on Rockwood radiographs has high reliability and good reproducibility, in which impingement type of acromion is closely related to supraspinatus tendon tear. Compared with the traditional classification and AHD, the new classification method has more diagnostic value than for rotator cuff injury.

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

PurposeVisualization 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).MethodsA 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.ResultsAgreement 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).ConclusionAnatomical 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.

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

Assessment on whether radiographic parameters of the acromion measured in radiographs change significantly after anterolateral acromioplasty. 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. 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). 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. IV, diagnostic study, case series.

Progression of Symptomatic Partial-Thickness Rotator Cuff Tears: Association With Initial Tear Involvement and Work Level.

Background:Partial-thickness rotator cuff tears (PTRCTs) often progress to full-thickness rotator cuff tears (FTRCTs). Thus, it is important to analyze the risk factors for tear progression to determine the proper timing of repair.Purpose:To identify the risk factors associated with progression of PTRCT.Study Design:Case-control study; Level of evidence, 3.Methods:Included were 89 patients diagnosed with PTRCT on magnetic resonance imaging (MRI) scans who underwent nonoperative treatment at the authors’ institution between August 2012 and August 2019. Patient characteristics, shoulder stiffness (compared with the contralateral shoulder); work level (classified as high [heavy manual labor], medium [manual labor with less activity], and low [sedentary activity]); and radiological factors including initial tear size, acromion type (flat, curved, hooked, or heel-shaped), and initial tear involvement (as a percentage of the rotator cuff tendon footprint length) were analyzed to assess their association with tear progression, defined as >20% increase in tear involvement.Results:The mean MRI follow-up period was 22.3 ± 17.2 months (median, 16.1 months; range, 6.4-89.5 months), and tear progression was observed in 12 patients (13.5%). In these 12 patients, tear involvement increased by 60% of the rotator cuff footprint, while mediolateral (ML) and anteroposterior (AP) tear sizes progressed by 1.1 and 1.8 mm, respectively. Univariate regression analysis showed that shoulder stiffness (P = .031), work level (P = .001), initial tear involvement (P < .001), ML and AP tear sizes (P < .001 and P = .005, respectively), and acromion type (P = .003) were significantly associated with tear progression. Multivariate regression analysis showed that initial tear involvement (odds ratio [OR], 1.053; 95% CI, 1.006-1.102; P = .026) and high work level (OR, 15.831; 95% CI, 1.150-217.856; P = .039) were independent risk factors for tear progression. The cutoff value for initial tear involvement was 47.5% (sensitivity, 81.8%; specificity, 85.7%).Conclusion:Tear progression was observed in 14% of patients with PTRCT in this study. To predict tear progression, evaluating the tear involvement during initial MRI is essential. The risk of tear progression increased with initial tear involvement >47.5% and a heavy work level.