The Coracohumeral Distance in Shoulders With Traumatic and Degenerative Subscapularis Tendon Tears

Higher Upper Subscapularis Goutallier Grade and Coracohumeral Distance Narrowing Are Predictive of Subscapularis Tears in Patients Undergoing Arthroscopic Rotator Cuff Repair

PURPOSE

To evaluate the relation between subscapularis (SSC) Goutallier grade or coracohumeral distance (CHD) and SSC tears, as well as the relation between these radiographic variables and long head of the biceps tendon lesions.

METHODS

A retrospective analysis was conducted on prospectively maintained data on patients who underwent arthroscopic rotator cuff repair of SSC tears between 2011 and 2021 with at least 6 months of follow-up. Patients with identified subscapularis tears during arthroscopy were included. A control group was established by randomly selecting patients without SSC tears from the same study period. Goutallier grading and CHD were obtained from preoperative magnetic resonance imaging (MRI) scans. Receiver operating characteristic analysis was conducted to define optimal cutoff values for these diagnostic measures.

RESULTS

The study included 735 patients with SSC tears and 249 patients in the control group. Comparing subscapularis tear and intact groups' Goutallier grades revealed significant differences in infraspinatus, upper and lower SSC, and overall SSC (P < .001). No significant difference was detected in supraspinatus Goutallier grade (P = .364). An SSC tear was observed in 58.3% (n = 265) of patients with Goutallier grade 0 of the upper SSC, 77.1% (n = 195) of patients with grade 1 changes, 98.7% (n = 155) with grade 2 changes, and 100% of grade 3 or 4 changes. Goutallier grade of the upper SSC showed a significant correlation with tear size (rs = 0.533; P < .01). CHD measurements were lower in individuals with SSC tears compared to those without tears (6.6 ± 1.7 vs 9.6 ± 1.8; P < .001). Upper SSC Goutallier grade >1 had an acceptable area under the curve (AUC) of 0.742. CHD of 7.96 mm or less had an excellent predictive AUC of 0.879.

CONCLUSIONS

Higher Goutallier grade and CHD narrowing are potential associations predictive of SSC tears. Routine MRI assessment of muscle of the upper SSC and the CHD can contribute to the diagnostic accuracy of SSC tears and offer valuable information regarding the severity of such tears.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Is it the subcoracoid impingement or the subacromial impingement that tears the subscapularis tendon? A comparison of the MRI findings of the operated and healthy shoulders of the patients

BACKGROUND

: The purpose of this study is to investigate whether the etiological factors accepted as causes of idiopathic subscapularis tears are true or not when the comparison is made with the opposite side healthy shoulder of the patients who underwent arthroscopic repair for an isolated subscapularis tear.

METHODS

Sixteen patients who underwent shoulder arthroscopy between February 2016 and January 2018 and were diagnosed with isolated subscapularis tear were evaluated. The coracohumeral distance (CHDax), coracoid overlap (CO), and tuberculum minus cysts (TMC) were evaluated on the axial images of the MRI studies while the acromiohumeral distance (AHDsag), CHDsag, and subscapularis tendon slip number (STSN) on the sagittal oblique images and the AHDcor and SLAP lesion on the coronal oblique images. Degeneration of the coracoacromial ligament was evaluated during arthroscopy.

RESULTS

The mean CHDsag (11.26-10.08), CHDax (10.63-9.98), CO (14.2-15.43), AHDsag (8-7.66), and AHDcor (7.65-7.68) measurements (operated side-healthy side, respectively) were statistically similar (p > 0.05). No statistically significant difference was found between TMC and STSN in healthy and operated shoulders (p > 0.05). There was mild coracoacromial ligament fraying in 4 (25%) and obvious coracoacromial ligament fraying in 8 (50%) which indicated subacromial impingement in 75% of the patients.

DISCUSSION

The parameters of the coracoid process did not reveal any significant difference between the operated (for an isolated subscapularis tear) and opposite-side healthy shoulders of the patients. However, coracoacromial ligament degeneration was present in 75% of the patients.

Alteration in coracohumeral ligament and distance in people with symptoms of subcoracoid impingement

BACKGROUND

Differentiation between subacromial impingement versus subcoracoid impingement are important for the treatment target. We evaluated the correlations between coracohumeral ligament (CHL) thickness and distance (CHD) and characterized the CHL and subscapularis (SSC) in subcoracoid impingement subjects.

METHODS

An observational, cross-sectional study was carried out. Twenty subcoracoid impingement subjects and age/gender matched controls were assessed in 4 different shoulder positions by ultrasonography.

RESULTS

Moderate correlations between CHL thickness with CHD (r = 0.455 in neutral rotation, p = 0.044; r = 0.483 in interior rotation, p = 0.031) were found in subacromial subjects. Subcoracoid impingement subjects had greater CHL thickness (difference = 0.3 mm, effect size = 0.85, p = 0.006), SSC tendon thickness (difference = 0.7 mm, effect size = 0.92, p = 0.01) and SSC/CHD occupation ratio (difference = 8%, effect size = 0.95, p = 0.005) compared with the control.

CONCLUSIONS

Coracohumeral distance is related to ligament thickness, especially in subacromial impingement subjects. Increased coracohumeral ligament and subscapularis thickness as well as decreased subscapularis/coracohumeral distance occupation ratio are characterized in subcoracoid impingement subjects. These quantitative measurements can be useful in identifying patients at risk of subcoracoid impingement from subacromial impingement.

In Vivo Anatomical Research by 3D CT Reconstruction Determines Minimum Acromiohumeral, Coracohumeral, and Glenohumeral Distances in the Human Shoulder: Evaluation of Age and Sex Association in a Sample of the Chinese Population

Accurate measurement of the minimum distance between bony structures of the humeral head and the acromion or coracoid helps advance a better understanding of the shoulder anatomical features. Our goal was to precisely determine the minimum acromiohumeral distance (AHD), coracohumeral distance (CHD), and glenohumeral distance (GHD) in a sample of the Chinese population as an in vivo anatomical analysis. We retrospectively included 146 patients who underwent supine computed tomography (CT) examination of the shoulder joint. The minimum AHD, CHD, and GHD values were quantitatively measured using three-dimensional (3D) CT reconstruction techniques. The correlation between minimum AHD, CHD, and GHD value and age with different sexes was evaluated using Pearson Correlation Coefficient. The mean value of minimum AHD in males was greater than that in females (male 7.62 ± 0.98 mm versus female 7.27 ± 0.86 mm, p = 0.046). The CHD among different sexes differed significantly (male 10.75 ± 2.40 mm versus female 8.76 ± 1.38 mm, p < 0.001). However, we found no statistical differences in GHD with different sexes (male 2.00 ± 0.31 mm versus female 1.96 ± 0.36 mm, p > 0.05). In terms of age correlation, a negative curve correlation existed between age and AHD among the different sexes (male R2 = 0.124, p = 0.030, female R2 = 0.112, p = 0.005). A negative linear correlation was found in CHD among the different sexes (male R2 = 0.164, p < 0.001, female R2 = 0.122, p = 0.005). There were no differences between age and minimum GHD in both sexes. The 3D CT reconstruction model can accurately measure the minimum AHD, CHD, and GHD value in vivo and is worthy of further investigation for standard clinical anatomical assessment. Aging may correlate with AHD and CHD narrowing for both sexes.

Morphology of the coracoid process as a predictor of articular-side tear at the upper border of the subscapularis

BACKGROUND

Articular-side tear at the upper border of the subscapularis (SSC-AST) is often detected during shoulder arthroscopic surgery, although its exact pathology remains unknown. The purpose of this study was to investigate the correlation between various characteristics of the coracoid process, including classification of the morphology of the coracoid process tip, and the presence of SSC-AST.

METHODS

This retrospective, case-controlled study included patients who underwent arthroscopic subacromial decompression with or without rotator cuff repair between January 2018 and September 2021. A total of 130 shoulders in 124 patients, including 77 male and 53 female shoulders (mean age at surgery, 64 years [range, 39-88 years]), were included in this study. Three-dimensional (3D) computed tomography examination was performed preoperatively, and the following indices were measured: coracoid proximal length, coracoid distal length, coracoid angle, coracoglenoid angle, offset of the coracoid process and glenoid (anterior, lateral, and superior offset), and coracoid base angle. The morphology of the tip of the coracoid process was classified into 3 types according to 3D reconstructed views: flat type, round type, and beak type. The presence of SSC-AST was intraoperatively evaluated arthroscopically via a posterior glenohumeral portal. Morphologic risk factors for SSC-AST were evaluated between SSC-AST cases (group T) and non-SSC-AST cases (group N) by multivariable logistic analysis. In addition, the correlation between the incidence of SSC-AST and classification of the tip of the coracoid process was analyzed.

RESULTS

SSC-AST was present in 53 shoulders (40.8%). Group T patients were significantly older than group N patients (68.4 ± 10.0 years vs. 61.5 ± 11.8 years, P < .001). No sex difference was detected between the 2 groups (28 male and 25 female shoulders in group T vs. 49 male and 28 female shoulders in group N, P = .28). Multivariate analysis of morphologic parameters between the 2 groups detected a smaller superior offset as a risk factor for SSC-AST (odds ratio, 0.91; 95% confidence interval, 0.84-0.98; P = .01). No significant differences were found in the other parameters. Regarding classification of the tip of the coracoid process, round- and beak-type coracoid tips had a significantly higher rate of SSC-AST than flat-type tips (flat type, 21.8%; round type, 64.7%; and beak type, 46.3%) (P < .001).

CONCLUSIONS

Evaluation of the correlation between the morphology of the coracoid process on 3D computed tomography and the presence of SSC-AST visualized during arthroscopy indicated a significant association between SSC-AST and the morphology of the coracoid process.

Current concepts review in the management of subscapularis tears

Subscapularis (SSc) is the prime internal rotator of shoulder. It is the most powerful rotator cuff muscle, maintaining the anterior force couple of shoulder. The tears in SSc as any other rotator cuff muscles might result from a traumatic event or more commonly from intrinsic degeneration. With the advent and widespread use of shoulder arthroscopy, SSc tears, which were once considered as "forgotten or hidden lesions" are now being increasingly recognized. Isolated SSc tears are relatively rare. They occur in combinations. Clinically internal rotation can be near normal because of the compensation provided by other internal rotators. It is not uncommon for patients with SSc tear to be normal on routine physical examination. The Bear Hug test (BHT) has high sensitivity and accuracy in the diagnosis of SSc tear. The combined use of BHT with Belly Press Test has been found optimal for diagnosis. US is an accurate and reliable method for diagnosing SSc tears and outperformed MRI in diagnosing partial-thickness SSc tears. The MRI is currently the most advanced imaging available for diagnosis. The specificity is up to 100%. However, the sensitivity is between 36 and 40%. The earliest classification system for SSc tears was by Fox et al. The commonly used classification is by Lafosse et al. The recent system by Yoo et al. is based on the insertion of SSc. The comma sign is gaining importance not only in arthroscopic diagnosis but also in MRI identification and repair of SSc. The mode of management is mainly arthroscopic. The techniques of repair of SSc are continuously progressing. However, there is no clear consensus on the double vs single-row repairs, biceps tendon management, and the role of coracoplasty. Future research must focus on these areas. Reserve shoulder arthroplasty is reserved for salvage in older age groups. Tendon transfers are performed in young active individuals with irreparable tears.

Biomechanical Analysis of Coracoid Stability After Coracoplasty: How Low Can You Go?

Background:

Arthroscopic coracoplasty is a procedure for patients affected by subcoracoid impingement. To date, there is no consensus on how much of the coracoid can be resected with an arthroscopic burr without compromising its stability.

Purpose:

To determine the maximum amount of the coracoid that can be resected during arthroscopic coracoplasty without leading to coracoid fracture or avulsion of the conjoint tendon during simulated activities of daily living (ADLs).

Study Design:

Controlled laboratory study.

Methods:

A biomechanical cadaveric study was performed with 24 shoulders (15 male, 9 female; mean age, 81 ± 7.9 years). Specimens were randomized into 3 treatment groups: group A (native coracoid), group B (3-mm coracoplasty), and group C (5-mm coracoplasty). Coracoid anatomic measurements were documented before and after coracoplasty. The scapula was potted, and a traction force was applied through the conjoint tendon. The stiffness and load to failure (LTF) were determined for each specimen.

Results:

The mean coracoid thicknesses in groups A through C were 7.2, 7.7, and 7.8 mm, respectively, and the mean LTFs were 428 ± 127, 284 ± 77, and 159 ± 87 N, respectively. Compared with specimens in group A, a significantly lower LTF was seen in specimens in group B (P = .022) and group C (P < .001). Postoperatively, coracoids with a thickness ≥4 mm were able to withstand ADLs.

Conclusion:

While even a 3-mm coracoplasty caused significant weakening of the coracoid, the individual failure loads were higher than those of the predicted ADLs. A critical value of 4 mm of coracoid thickness should be preserved to ensure the stability of the coracoid process.

Clinical Relevance:

In correspondence with the findings of this study, careful preoperative planning should be used to measure the maximum reasonable amount of coracoplasty to be performed. A postoperative coracoid thickness of 4 mm should remain.

Relationship between Radiological Measurement of Subcoracoid Impingement and Subscapularis Tendon Lesions

Background

The value of radiological measurements of subcoracoid impingement such as the coracohumeral interval in predicting subscapularis tendon injuries is controversial. We aimed to assess the relationship between radiological measurements of subcoracoid impingement and subscapularis tendon lesions in young and middle-aged adults.

Methods

This study was designed as a retrospective cohort study. Patients between the ages of 18–55 years without a history of shoulder surgery or major trauma were included and patients with arthritis, instability, or retracted rotator cuff tears were excluded from the study. Magnetic resonance images were evaluated and patients were grouped into two according to the subscapularis tendon condition: normal or pathologic. Glenoid version, axial coracohumeral distance, coracoglenoid angle, coracoid index, sagittal coracoid-glenoid tubercule distance, and axial coracoacromial inclination-glenoid version difference were measured for all patients. Measurement findings were compared between the groups. Correlation analysis was performed for age and radiologic measurements. A p < 0.05 was considered statistically significant for all tests.

Results

A total of 298 patients, 107 women (35.1%) and 191 men (64.9%), with a mean age of 34.46 ± 10.10 years (range, 18–55 years) were examined in the study. Subscapularis tendon pathology was noted in 85 patients (28.5%). The diagnosed pathologies were tendinosis in 48 patients (56.5%), partial tears in 28 (32.9%), and full thickness tears in 9 (10.6%). A significant relationship was observed between increasing age and subscapularis tendon lesions (p = 0.001). There was no statistically significant relationship between subscapularis pathology and calculated measurements. Axial coracohumeral distance and coracoglenoid angle measurements showed a statistically significantly negative correlation with age. A positive correlation was found between axial coracohumeral distance and coracoglenoid angle measurements (p < 0.001) and also between glenoid version and coracoid index measurements (p = 0.004). Axial coracohumeral distance and coracoglenoid angle measurements showed a negative correlation with glenoid version and coracoid index measurements (p < 0.05).

Conclusions

In this study, the coracohumeral distance and coracoglenoid angle decreased and the incidence of subscapularis tendon lesions increased as the age progressed. However, no relationship was found between radiological measurements and subscapularis tendon lesions.

Bilateral coracohumeral distance discrepancy is associated with subscapularis tear in rotator cuff rupture patients

PURPOSE

To describe the bilateral coracohumeral morphological discrepancy in rotator cuff rupture patients with and without subscapularis (SSC) involvement and to investigate its association with SSC tears.

METHODS

Two hundred and thirteen consecutive patients who were scheduled to have arthroscopic rotator cuff repair were prospectively enrolled in the current study. Patients with acute traumatic rotator cuff rupture, glenohumeral osteoarthritis, bilateral rotator cuff rupture, recurrent shoulder instability, systemic inflammatory disease, and previous shoulder surgery history were excluded. Coracohumeral distance (CHD), coracoid overlap (CO), lesser tuberosity index (LTI) and acromiohumeral interval (AHI) were measured bilaterally using CT scans. Based on arthroscopic findings, patients were included in either the SSC tear group (n = 72) or the control group (n = 141).

RESULTS

In the SSC tear group, the affected shoulder possessed a significantly smaller CHD [95% confidence interval (CI) 6.1-7.2 vs. 7.2-8.0 mm, p < 0.0001], larger LTI (95% CI 9.4-9.9 vs. 9.0-9.6 mm, p < 0.0001), and smaller AHI (95% CI 5.0-5.5 vs. 7.1-7.5 mm, p < 0.0001) than the contralateral normal shoulder. In the control group, there was no significant difference between bilateral CHD and CO, and the AHI bilateral discrepancy was less distinct. CO did not differ significantly in the bilateral comparison in either group. Among all evaluated parameters, bilateral CHD discrepancy was the best predictor of SSC tears, with an area under the curve (AUC) of 0.882. A cutoff value of 0.5 mm had a sensitivity of 76.4% and specificity of 99.3% for SSC tears.

CONCLUSION

The CHD values are significantly different between affected and contralateral shoulders in SSC tear patients. Bilateral CHD discrepancy is closely associated with subcoracoid impingement and SSC tears, and its presence warrants specific intraoperative SSC inspection.

LEVEL OF EVIDENCE

Level II.

In vivo effects of two shoulder girdle motor control exercises on acromiohumeral and coracohumeral distances in healthy men

INTRODUCTION

Altered motor control and proprioceptive deficits are associated with kinematics dysfunctions and may cause alterations in subacromial space (SAS) that could lead to shoulder pathologies. Dimensions of the subacromial space, as well as interventions aimed at its normal restitution, can be explored by ultrasound (US).

OBJECTIVE

To describe the effect of two shoulder girdle motor control exercises with cognitive training strategies on SAS dimensions, measured with US.

METHODS

Cognitive movement control strategies, with visual and haptic feedback were applied on 21 healthy participants. SAS dimensions were measured through in vivo variations of acromiohumeral (AHD) and coracohumeral distances (CHD) using US.

RESULTS

Our results show that as exercise repetitions are performed, an increasing trend in both measures can be observed, being wider for AHD (i.e. humeral head descent exercise) than CHD (i.e. scapular retraction exercise).

CONCLUSION

Specific cognitive and motor control exercises improve congruence joint and centering of the humeral head.

Is shoulder geometry important for rotator cuff tears?

PURPOSE

This study is aiming to evaluate some specific anatomic shoulder parameters such as the lateral acromial angle (LAA), acromial index (AI), coracohumeral distance (CHD) and critical shoulder angle (CSA) in rotator cuff tears.

METHODS

A total of 100 cases consisting of 50 patients with rotator cuff tears and 50 patients without rotator cuff tears, who underwent shoulder MRI (mangnetic resonance imaging) examination in Istanbul Medipol University Orthopedics and Traumatology Department, participated in this study. In this retrospective study, CCA, LAA, AI and CSA were evaluated in MRI in order to shed light on the theories of rotator cuff tears.

RESULTS

There was no significant difference (P ˃ .05) in acromial index and coracohumeral distance in the patient group. Lateral acromial angle and critical shoulder angle were significantly different in the patient group compared to the control group (P < .05). There was a weak negative correlation between CSA and CHD.

CONCLUSION

In our study, we found that patients with smaller LAA and higher CSA values in MRI images are prone to have rotator cuff tears. Further studies are needed in order to evaluate whether this association has predictive value.

Analysis of the results and adverse factors of arthroscopic repair of degenerative subscapular lesions

OBJECTIVE

To carry out a review of degenerative subscapularis ruptures (SSC) after their arthroscopic repair and to evaluate whether the results are comparable in terms of pain and function to those of younger patients with traumatic ruptures.

METHODS

The data of 80 SSC tears of the 660 rotator cuff tears operated on by the same team of surgeons from June 2008 to June 2018 were retrospectively reviewed. The clinical data of the surgical indications were collected: age, gender, laterality, intervention delay, associated pathologies, location of pain, value of the Visual Analogue Scale (VAS) and the Constant-Murley test (CMT); surgical data were also collected: type and size of lesion, associated biceps injury and associated surgical procedure, coracoid stenosis and associated surgical procedure, number and type of anchors used. A statistical study was performed with multiple linear regression test, parametric tests (Student's t or ANOVA) and non-parametric tests.

RESULTS

Of 80 patients, 36 were women (45%) and 44, men (55%); mean age 61years (range 47 to 81); mean delay of surgery 3.5months (range 1 to 6); right shoulder affected in 46 cases (57.5%), left in 34 (42.5%); 22 (27.5%) were isolated lesions, 58 (72.5%) were associated with supraspinatus rupture (SE). The mean improvement was 5.0 points in terms of the VAS and 39.9 points on average in the CMT. New breakage rate, 1.25%. Adverse factors: size of the tear, delay in intervention, women. Patients with type I-B rupture have a better overall result in the CMT than types I-A and III. The longer the delay, the worse results are observed, both for the VAS and the CMT. Women present worse and statistically significant results both in the VAS (P=.00) and in the CMT (P=.01).

CONCLUSIONS

Excellent and good results have been obtained in this group of patients, but there are adverse factors such as the size of the tear, the duration of the symptoms and the association of other pathologies, especially in women.

Less than 9.5-mm coracohumeral distance on axial magnetic resonance imaging scans predicts for subscapularis tear

Background

Diagnosis of subscapularis (SSC) tendon lesions on magnetic resonance imaging (MRI) can be challenging. A small coracohumeral distance (CHD) has been associated with SSC tears. This study was designed to define a specific threshold value for CHD to predict SSC tears on axial MRI scans.

Methods

This retrospective study included 172 shoulders of 168 patients who underwent arthroscopic surgery for rotator cuff tear or glenohumeral instability. Diagnostic arthroscopy confirmed an SSC tear in 62 cases (36.0%, test group a), rotator cuff tear tears other than SSC in 71 cases (41.3%, control group b) and glenohumeral instability without any rotator cuff tear in 39 cases (22.7%, zero-sample group c). All patients had a preoperative MRI of the shoulder (1.5T or 3T). Minimum CHD was measured on axial fat-suppressed proton density-, T2-, or T1-weigthed sequences. Receiver operating characteristics analysis was used to determine the threshold value for CHD, and sensitivity and specificity were calculated.

Results

CHD measurement had a good interobserver reliability (Intraclass correlation coefficient 0.799). Mean CHD was highly significantly (P < .001) less for test group a (mean 7.3 mm, standard deviation ± 2.2) compared with control group b (mean 11.1 mm, standard deviation ± 2.3) or zero-sample group c (mean 13.6 mm, standard deviation ± 2.9). A threshold value of CHD <9.5 mm had a sensitivity of 83.6% and a specificity of 83.9% to predict SSC tears.

Conclusion

A CHD <9.5 mm on MRI is predictive of SSC lesions and a valuable tool to diagnose SSC tears.

Measurement of the coracohumeral distance on magnetic resonance imaging in a large patient cohort

BACKGROUND

Coracoid impingement syndrome is an increasingly recognized etiology of anterior shoulder pain. Numerus studies have documented the coracohumeral distance (CHD) as a primary or secondary measurement in symptomatic individuals, but there lacks an evaluation of CHD in a large cohort of asymptomatic individuals. The purpose of this study was to quantify a normative distribution of the CHD in a large cohort of healthy, asymptomatic subjects with no history of impingement or shoulder instability.

METHODS

Incoming first-year students in the United States Military Academy were offered enrollment in this study as part of a prospective cohort to assess the normal anatomic relationships of the shoulder girdle. Magnetic resonance images were obtained, and a board-certified, fellowship-trained musculoskeletal radiologist performed measurements of the smallest distance from the coracoid to the humeral head on axial images.

RESULTS

Magnetic resonance images of 714 subjects were available for analysis, including 630 males and 84 females, with a total of 1120 individual shoulders with images of adequate quality. The mean CHD for all shoulders imaged was 13.7 mm. The mean CHD in male shoulders was 13.8 mm, and in female subjects the average was 12.4 mm.

CONCLUSIONS

This study is the largest of its kind to evaluate the CHD in asymptomatic, healthy shoulders to date and demonstrates a mean CHD of 13.7 mm for all subjects. This information can help to standardize "normal" ranges and act as a comparison for future work, when taken in the context of age and imaging in neutral rotation.

Acromial morphology is not associated with rotator cuff tearing or repair healing

BACKGROUND

The purposes of this study were to determine whether acromial morphology (1) could be measured accurately on magnetic resonance images (MRIs) as compared to computed tomographs (CTs) as a gold standard, (2) could be measured reliably on MRIs, (3) differed between patients with rotator cuff tears (RCTs) and those without evidence of RCTs or glenohumeral osteoarthritis, and (4) differed between patients with rotator cuff repairs (RCRs) that healed and those that did not.

METHODS

This is a retrospective comparative study. We measured coronal, axial, and sagittal acromial tilt; acromial width, acromial anterior and posterior coverage, and glenoid version and inclination on MRI corrected into the plane of the glenoid. We determined accuracy by comparison with CT via intraclass correlation coefficients (ICCs). To determine reliability, these same measurements were made on MRI by 2 observers and ICCs calculated. We compared these measurements between patients with a full-thickness RCT and patients aged >50 years without evidence of an RCT or glenohumeral osteoarthritis. We then compared these measurements between those patients with healed RCRs and those with a retorn rotator cuff on MRI. In this portion, we only included patients with both a preoperative MRI and a postoperative MRI at least 1 year from RCR. Only those patients without tendon defects on postoperative MRIs were considered to be healed. In these patients, we also radiographically measured the critical shoulder angle.

RESULTS

In a validation cohort of 30 patients with MRI and CT, all ICCs were greater than 0.86. In these patients, the inter-rater ICCs of the MRI measurements were >0.53. In our RCT group of 110 patients, there was greater acromial width [mean difference (95% confidence interval) = 0.1 (0, 0.2) mm, P = .012] and significantly less sagittal acromial tilt [9° (5°-12°), P < .001] than in our comparison group of 107 patients. A total of 110 RCRs were included. Postoperative MRI scans were obtained at a mean follow-up of 24.2 ± 15.8 months, showing 84 patients (76%) had healed RCRs. Aside from acromial width, which was 0.2 mm different and thus did not have clinical significance, there was no association between healing and any of the measured morphologic characteristics. Patients with healed repairs had significantly smaller tears in terms of both width (P < .001) and retraction (P < .001).

CONCLUSION

Although the acromion is wider in RCTs, the difference of 0.1 mm likely has no clinical significance. The acromion is more steeply sloped from posteroinferior to anterosuperior in those with RCTs. These findings call into question subacromial impingement due to native acromial morphology as a cause of rotator cuff tearing. Acromial morphology, critical shoulder angle, and glenoid inclination were not associated with healing after RCR. This study does not support lateral acromioplasty.

Do coracohumeral interval and glenoid version play a role in subscapularis tears?

Purpose

To study the effect of the coracohumeral interval and orientation of the glenoid for causation of subscapularis tears and literature review for the need of coracoplasty.

Methods

This is a retrospective cohort study of patients who underwent arthroscopic shoulder surgery from January 2013 to December 2017. The coracohumeral interval and orientation of the glenoid in patients with arthroscopically diagnosed subscapularis tears (group A, n = 40) were compared with 2 control groups (group B, n = 38 [intact subscapularis with supraspinatus and infraspinatus cuff tears] and group C, n = 39 [intact rotator cuff]). Group A1 (n = 23) consisted of the isolated subscapularis and combined subscapularis + supraspinatus tears, and group A2 (n = 17) all the 3 rotator cuff tears. The measurements were made on preoperative axial magnetic resonance imaging. Statistical analysis was performed to compare the groups.

Results

The mean coracohumeral interval was 8.81 ± 2.69 mm in group A and 10.62 ± 2.21 and 10.39 ± 2.59 mm in control groups B and C, respectively; this difference was statistically significant (P = .002 and .01, respectively). The mean glenoid version in patients with subscapularis tears was -3.7°, whereas the mean version in patients with intact cuff was -3.4°, and this difference was not statistically significant (P = .74). The mean glenoid version was -4.69° ± 4.22° in group A1 and -3.28° ± 4.04° in group B, with no statistically significant difference (P = .07).

Conclusion

The coracohumeral interval was significantly decreased in patients with subscapularis tears. The glenoid was retroverted in the subscapularis group but was not statistically significant.

Coracoid morphology is not associated with subscapularis tears

BACKGROUND

The observation of the roller-wringer effect fueled the idea that coracoid morphology is related to subscapularis pathology. We aimed to examine this relationship, specifically focusing on how the coracohumeral distance (CHD) and 2 new metrics of coracoid morphology relate to subscapularis tears.

METHODS

In this retrospective study, we identified consecutive patients 45 years or older who underwent shoulder arthroscopy for any indication. We blindly reviewed preoperative magnetic resonance imaging studies of each patient, measuring the CHD, lateral extent (LE), and caudal extent (CE) of the coracoid process. Patients' subscapularis condition was assessed via operative reports; stratified according to Lafosse grade criteria; and compared for differences in the CHD, LE, and CE by 1-way analysis of variance and 2-tailed t tests.

RESULTS

The study included 201 patients. Of these, 112 had no evidence of subscapularis injury, whereas Lafosse grade I injuries were identified in 52 patients; grade II, in 19; and grades III-V, in 18. The CHD, LE, and CE were not correlated with subscapularis injury (CHD, P = .36; LE, P = .36; and CE, P = .13).

CONCLUSIONS

We found no correlation between subscapularis injury and the CHD, LE, and CE. These findings support the idea that coracoid morphology may not be a cause of subscapularis pathology and suggest that coracoplasty may not be necessary prophylactically or as part of subscapularis repair.

Comparison of Functional and Radiological Outcomes of Tears Involving the Subscapularis: Isolated Subscapularis Versus Combined Anterosuperior Rotator Cuff Tears

Background:

Few studies have compared the clinical and radiological characteristics and outcomes in isolated subscapularis (SSC) and combined anterosuperior (AS) rotator cuff tears (RCTs). Furthermore, risk factors for retear after SSC repair and the effect of preoperative fatty degeneration require further evaluation.

Purpose:

To compare the functional and radiological outcomes of isolated SSC with combined AS RCTs after arthroscopic repair and to determine the risk factors for SSC retear in these 2 groups.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data from 30 patients in the isolated SSC group were compared with data from 110 patients in the combined AS group. All patients underwent primary arthroscopic rotator cuff repair between 2010 and 2016. Clinical outcomes were assessed through use of the visual analog scale for pain, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test at a mean follow-up of 26.7 months (range, 24-96 months). SSC tendon integrity was examined via magnetic resonance imaging, computed tomography arthrogram, or ultrasonography at least 1 year after surgery.

Results:

The isolated SSC group had a greater proportion of males and the patients were younger compared with the combined AS group (both P < .050). The incidence of trauma was high but not significantly different between groups (56.7% vs 40.9%; P = .180). Clinical outcome measures and radiological outcomes in terms of retear were not statistically different between both groups (16.7% vs 8/5%; P = .337). The optimal cutoff values for the risk of SSC tendon retear in both groups were 19-mm retraction and 16-mm superoinferior dimension (P = .048). Unfavorable preoperative fatty degeneration of the SSC muscle (grades 3 and 4) was a significant risk factor for retear (odds ratio, 9.8; P < .001).

Conclusion:

Isolated SSC and combined AS RCTs were comparable except for patient age and sex; both had a high incidence of traumatic history. The current data suggest that the risk factors for retear after SSC repair in RCTs involving the SSC were tear size greater than 19 mm of retraction and unfavorable fatty degeneration (grade 3 or higher) of the SSC muscle.

Analysis of glenohumeral morphological factors for anterior shoulder instability and rotator cuff tear by magnetic resonance imaging

OBJECTIVE

The aim of this study was to investigate whether there are glenohumeral morphological differences between normal population, glenohumeral instability, and rotator cuff pathology.

METHOD

In this study, shoulder magnetic resonance (MR) images of 150 patients were evaluated. Patients included in the study were studied in three groups of 50 individuals: patients with anterior shoulder instability in group 1, patients with rotator cuff tear in group 2, and control subjects without shoulder pathology in group 3.

RESULTS

There were statistically significant differences between groups in evaluations for glenoid version, glenoid coronal height, glenoid coronal diameter, humeral axial and coronal diameters, and coracohumeral interval distances. Significant differences were observed between groups 2 and 3 in glenoid axial diameter, glenoid coronal height, glenoid depth, humeral coronal diameter, and coracohumeral distances.

CONCLUSION

The results obtained in this study suggest that glenoid version, glenoid coronal height and diameter, humeral diameter, and coracohumeral interval parameters in glenohumeral morphology-related parameters in patients with anterior instability are different from those of normal population and patients with rotator cuff pathology. In cases where there is a clinically difficult diagnosis, these radiological measurements will be helpful to clinicians in diagnosis and treatment planning, especially in cases of treatment-resistant cases.

Magnetic resonance imaging based coracoid morphology and its associations with subscapularis tears: a new index

BACKGROUND

We aimed to assess the validity of magnetic resonance imaging (MRI) in assessing the subcorocoid space and determine the validity of novel sagittal plane subcorocoid space measurements.

METHODS

We assessed 33 arthroscopically proven subscapularis tears with MRIs compared to 33 (instability) controls with normal subscapularis tendons. Three examiners analyzed MRIs for seven static indices of corocoid morphology, in axial and sagittal planes. We explored reviewer variation using intraclass correlation coefficients (ICC) and differences between the two groups was explored using t-tests.

RESULTS

Groups were similar in characteristics but different in age (cases = 53, controls = 23). ICC showed good (2/7) or excellent (5/7) reliability. Small differences(<1.6 mm) were identified between subscapularis tears and controls in coraco-humeral distance, in axial (p = 0.092) and sagittal planes (p = 0.045). There were statistically significant differences between groups when analyzing the angular projection of the coracoid from the glenoid, in both sagittal (p < 0.0001) and axial planes (p = 0.045).

CONCLUSIONS

Acute inferior angulation of the corocoid in the sagittal plane may be associated with subscapularis tears. Static indices are measured within the scapula and not affected by arm position. MRI reliably provided a platform to assess the coracoid. Based on this, we currently consider corocoplasty in patients with subscapularis tears and a sagittal coroco-glenoid angle <60^o to reduce potential impingement.

Anatomic Study of Subcoracoid Morphology in 418 Shoulders: Potential Implications for Subcoracoid Impingement

Background:

Subcoracoid impingement has been implicated as a cause of anterior shoulder pain and subscapularis tendon tears.

Purpose/Hypothesis:

The purpose of this study was to evaluate the bony anatomy of the coracoid process and the subcoracoid space. We hypothesized that age-related changes that may contribute to subcoracoid impingement occur in the subcoracoid space.

Study Design:

Descriptive laboratory study.

Methods:

In total, 418 skeletal shoulder specimens were included in this study. We utilized 214 shoulders from a young cohort (25-35 years of age) and 204 shoulders from an older cohort (>55 years of age) for comparison. We evaluated several morphological characteristics of the coracoid process and the subcoracoid space: coracoid width, coracoid shape, coracoid thickness, and subcoracoid distance. Each coracoid was observed for the presence of spurring or other morphological changes.

Results:

The mean anteroposterior (AP) thickness of the coracoid tip was 7.9 and 9.4 mm in our young female and male cohorts, respectively, while the mean AP thickness was 8.1 and 9.7 mm in our older female and male cohorts, respectively. The coracoid tip was hooked in 31 of 108 young female shoulders compared with 55 of 102 older female shoulders, and the coracoid tip was hooked in 25 of 106 young male shoulders compared with 45 of 102 older male shoulders. The mean subcoracoid distance in neutral rotation was 14.8 and 12.5 mm in young and older female shoulders, respectively, while the mean subcoracoid distance in internal rotation in these same cohorts was 8.7 and 7.0 mm, respectively. The mean subcoracoid distance in neutral rotation was 14.8 and 13.3 mm in young and older male shoulders, respectively, while the mean subcoracoid distance in internal rotation was 8.6 and 8.1 mm in young and older male shoulders, respectively.

Conclusion:

The principal findings of our study demonstrate that anatomic changes implicated in subcoracoid impingement may be developmental and worsen with age. The subcoracoid space was narrower in our older cohort of shoulders. Additionally, these older shoulders also had a greater AP width and a more hooked coracoid compared with young shoulders.

Clinical Relevance:

Narrowing of the subcoracoid space has been shown to be implicated as a cause of anterior shoulder pain and subscapularis tendon tears. This is the first study to show that the morphological changes implicated in subcoracoid impingement become more prevalent with age. This may help to explain the increasing prevalence of subscapularis tendon tears in older patients. Furthermore, subcoracoid decompression may be seen as an option for older patients with anterior shoulder pain and subscapularis tendon tears.

Subscapularis Tendon Slip Number and Coracoid Overlap Are More Related Parameters for Subcoracoid Impingement in Subscapularis Tears: A Magnetic Resonance Imaging Comparison Study

PURPOSE

To investigate the effects of the subscapularis tendon slip number (STSN) and coracoid morphology by magnetic resonance imaging in patients with and without subscapularis tears.

METHODS

Patients who underwent shoulder arthroscopy between February 2004 and June 2015 were re-evaluated. Those with a subscapularis tear (study group) and those with other pathologies (control group) were compared with each other. Magnetic resonance imaging scans and surgery videos of the patients were reassessed. Transverse and sagittal coracohumeral distance (CHD), coracoid overlap (CO), coraco-coracoid base angle (CBA), coracoglenoid distance (CGD), and STSN were measured.

RESULTS

The study and control groups comprised 141 and 78 patients, respectively. The mean age was 57.01 ± 10.95 (similar in both the groups). The mean transverse CHD and sagittal CHD were not different between the groups and also between female and male patients. For the study and control groups, the mean CBA and CGD values were also similar. The mean CO was 24.01 ± 4.9 and 21.29 ± 4.58 for the study and control groups, respectively (P < .001). With the receiver operating characteristic curve of the CO, the sensitivity was 62% and the specificity was 64% at the cutoff value of 22.85 mm. The STSN was in the range between 1 and 6; the STSN was 3 or less in 61.5% of the study group and in 38.5% of the control group (P = .005).

CONCLUSIONS

The CO was the most valuable parameter predicting any potential subcoracoid impingement, and the STSN was inversely correlated with subscapularis tears. However, in predicting a potential subcoracoid impingement, the CHD measurements were not significant, as well the CGD and CBA.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Three-Dimensional Morphometric Analysis of the Coracohumeral Distance Using Magnetic Resonance Imaging

There have been no studies investigating three-dimensional (3D) alteration of the coracohumeral distance (CHD) associated with shoulder motion. The aim of this study was to investigate the change of 3D-CHD with the arm in flexion/internal rotation and horizontal adduction. Six intact shoulders of four healthy volunteers were obtained for this study. MRI was taken in four arm positions: with the arm in internal rotation at 0°, 45°, and 90° of flexion, and 90° of flexion with maximum horizontal adduction. Using a motion analysis system, 3D models of the coracoid process and proximal humerus were created from MRI data. The CHD among the four positions were compared, and the closest part of coracoid process to the proximal humerus was also assessed. 3D-CHD significantly decreased with the arm in 90° of flexion and in 90° of flexion with horizontal adduction comparing with that in 0° flexion (P<0.05). In all subjects, lateral part of the coracoid process was the closest to the proximal humerus in these positions. In vivo quasi-static motion analysis revealed that the 3D-CHD was narrower in the arm position of flexion with horizontal abduction than that in 0° flexion. The lateral part on the coracoid process should be considered to be closest to the proximal humerus during the motion.