Abstract
Background
The aim of this study was to identify the diagnostic magnetic resonance imaging (MRI) findings in 47 shoulders with subcoracoid impingement syndrome by comparison with 100 normal shoulders.
Material/Methods
The subcoracoid impingement syndrome group consisted of 47 shoulders with subcoracoid impingement syndrome and the normal group consisted of 100 normal shoulders. The MRI parameters – coracoids-humeral distance (CHD), coracoid index (CI), height of the lesser tuberosity (HLT), coracoid obliquity (CO), coracoglenoid angle (CGA), coracohumeral angle (CHA), width of the subscapular tendon (WST), and contact distance between subscapular tendon and coracoid process (CD) – were compared between the subcoracoid impingement syndrome group and the normal group. The areas under the curves (AUCs) from the receiver operating characteristic (ROC) for single MRI parameters were recorded, in which the MRI parameters with AUC exceeding 0.70 were included in the analysis of combined parameters. Comparisons of ROC were made among single parameters and combined parameters.
Results
For diagnosing subcoracoid impingement syndrome by using single MRI parameters (CHD, CI, HLT, CGA, CHA, WST, and CD), the AUCs were 0.963, 0.806, 0.745, 0.691, 0.613, 0.685, and 0.614, respectively, of which CHD had the largest AUC. CHD, CI, and HLT (AUC exceeding 0.70) were included in the study of the combined parameters. The AUC of combined CHD and HLT showed a significantly larger AUC than that of CHD (0.986 vs 0.963, P=0.036), and showed no significant difference compared with that of combined CHD, CI, and HLT (0.986 vs 0.987, P=0.882).
Conclusions
Measurement of the coracoid–humeral distance and height of the lesser tuberosity were key MRI diagnostic findings for subcoracoid impingement syndrome.
Keywords: Magnetic Resonance Imaging, Shoulder Impingement Syndrome, Coracoid Process
Background
Subcoracoid impingement syndrome is defined as impingement of the anterior soft tissues of the shoulder between the coracoid process and the lesser tuberosity, which causes fiber failure and damage, then partial or complete tearing of the subscapularis tendon, resulting in anterior shoulder pain [1–10].
There were some studies discussing the imaging index for diagnosing subcoracoid impingement syndrome. Some studies have shown that the coracohumeral distance (CHD) is the predictor for subcoracoid impingement syndrome on plain film, CT, and MRI [11–14], and the excessive extension of the coracoid process and variants in the lesser tuberosity anatomy are associated with subcoracoid impingement syndrome [4,11,15]. Other authors report that an increase in overall size of the tendon and disproportionate contact of the rotator cuff with surrounding structures were also associated with subcoracoid impingement syndrome [16–18]. Additionally, some angles, such as the coracoglenoid angle and coracohumeral angle, have been found to be indices for subcoracoid impingement syndrome [3,19,20].
However, other studies have shown different results. Radas and Pieper [21] found no correlation between the coracohumeral interval and subscapularis injury. Bergin et al [17] reported no significant relationship between the measured subcoracoid interval and severity of subscapularis tendon abnormalities. Some studies showed no correlation between subscapularis injury and MRI parameters [22,23].
We know that impingement syndrome is related to the position of anatomical structures in three-dimensional space; these studies with a single parameter are limited because subcoracoid impingement syndrome arises from a three-dimensional pathology [14]. We speculate that the diagnostic value of combining multiple parameters of MRI is better than that of a single parameter. Therefore, the purpose of this study was mainly to identify the diagnostic magnetic resonance imaging (MRI) findings in 47 shoulders with subcoracoid impingement syndrome by comparison with 100 normal shoulders.
Material and Methods
Patients
This study was approved by the Ethics Committee of Suzhou Municipal Hospital (approval no. KL901228). The requirement for informed consent was waived owing to the retrospective nature of the study.
This study included 100 normal shoulders and 47 shoulders with subcoracoid impingement syndrome. The diagnostic criteria of subcoracoid impingement syndrome are as follows: (1) MRI findings include narrowed subcoracoid space, increased signal and fraying of the subscapularis tendon; (2) tenderness of the soft tissue around the coracoid process or between the coracoid process and lesser tuberosity; (3) shoulder apprehension test can induce anterior shoulder pain, and the pain is relieved after retesting; (4) coracoid impingement test or modified Kennedy-Hawkins impingement sign was positive, and turned negative after subcoracoid infiltration of local anesthetics [15,24]. A total of 47 patients diagnosed with subcoracoid impingement syndrome (19 males and 28 females) undergoing shoulder MRI, with mean age of (47.19±10.08) and age range from 34 to 70 years, were included in this study. All of them had single shoulder disease, including 24 cases of right shoulder and 23 cases of left shoulder.
The range of the course on subcoracoid impingement syndrome was from 1 month to 1 year. All patients underwent a comprehensive shoulder physical examination before MRI. The normal group consisted of 100 volunteers. The inclusion criteria of normal group are as follows: no history of chronic shoulder pain, with normal shoulder function, no history of shoulder trauma and surgery, no obvious MRI features of subcoracoid impingement syndrome. The normal group included 51 males and 49 females, aged 24–76 years, with an average age of (48.74±12.14).
MRI Technique and Measurements
All MRI examination were performed using the 1.5 Tesla MRI system (Avanto 1.5T, Siemens, Berlin, Germany). All subjects lay in supine position with a loop coil around the shoulder. MRI was performed with the arm in neutral position. The scanning parameters are shown in Supplementary Table 1.
The coracoid-humeral distance (CHD) is defined as the minimal distance between the coracoid process and lesser tuberosity on an axial image [3,11]. The coracoid index (CI) is defined as the distance between coracoid process and glenoid process on an axial image [25]. The height of the lesser tuberosity (HLT) was defined as the length of the line through the highest point inside and outside the intertubercular sulcus and the parallel line through the bottom of the intertubercular sulcus. The coracoid obliquity (CO) was defined as the angle between the axis of the coracoid process and a horizontal line on the coronal image. The coracoid-glenoid angle (CGA) was measured as the angle between a line along the plane of the glenoid face and the apex of the coracoid on the axial image [3]. The coracoid-humeral angle (CHA) was measured as the included angle between the internal and external tangent lines of the humeral head through the tip of the coracoid process on the axial image [3]. The width of the subscapular tendon (WST) is the width of the subscapular tendon measured at the layer with the minimum CHD. The contact distance between subscapular tendon and coracoid process (CD) was defined as the distance between the superior edge of subscapular tendon and lower edge of the coracoid process. The detailed measurement is shown in Supplementary Figure 1. All measurements were performed independently by 2 radiologists using Neusoft PACS software (version 5.5.0.19075) and the average value was taken.
Statistical Analysis
Statistical analysis was performed using SPSS software (version 26, IBM, Armonk, NY, USA). Data were expressed as mean±standard deviation. The age difference between groups was tested by the independent-samples t test. Categorical variables such as sex and left-and-right side were compared between groups with the χ2 test. The differences of CHD, CI, HLT, CO, CGA, CHA, WST, and CD between groups were tested by Mann-Whitney U test.
To determine the best cut-off points, receiver operating characteristic (ROC) curves were designed for each studied variable and the Youden index was applied. The corresponding value with the highest Youden index was considered as the cut-off value with the best precision. Further analysis of the combined parameters included the MRI parameters with AUC exceeding 0.70. MedCalc software (version 9.6.2, MedCalc, Belgium) was used to compare ROC among single parameters and combined parameters. P<0.05 was considered statistically significant.
Results
The normal group (average age 56±14 years) included 51 men and 49 women, and the subcoracoid impingement syndrome group (average age 64±12 years) included 19 men and 28 women. The normal group included 48 left and 52 right shoulders, and the subcoracoid impingement syndrome group included 23 left and 24 right shoulders. There was no significant difference between the normal group and subcoracoid impingement syndrome group in age (t=1.017, P=0.136), sex, or left-and-right side (χ2=1.433, P=0.231; χ2=0.011, P=0.916) (Table 1).
Table 1.
Comparison of sex, left-and-right side, and age between normal and subcoracoid impingement syndrome groups.
| Normal group | Subcoracoid impingement syndrome group | Test statistics | P value | |
|---|---|---|---|---|
| Sex | χ2=1.433 | P=0.231 | ||
| Male | 51 | 19 | ||
| Female | 49 | 28 | ||
| Left-and-right side | χ2=0.011 | P=0.916 | ||
| Left | 48 | 23 | ||
| Right | 52 | 24 | ||
| Age | 56±14 | 64±12 | t=1.017 | P=0.136 |
The results are expressed as mean±standard deviation (SD).
The CHD, CI, HLT, CO, CGA, CHA, WST, CD of the normal group were 7.7±1.5mm, 16.0±3.3mm, 5.5±1.0 mm, 8.9±2.9°, 132.6±8.5°, 106.7±9.5°, 5.4±1.3 mm, and 8.9±2.3 mm, respectively. The CHD, CI, HLT, CO, CGA, CHA, WST, and CD of subcoracoid impingement syndrome group were 4.7±1.2 mm, 20.1±3.3 mm, 6.6 ±1.4 mm, 9.3±3.0°, 126.8±9.6°, 110.2 ±10.5°, 6.4±1.8 mm, and 10.5±3.8 mm, respectively. The CHD, CI, HLT, CGA, CHA, WST, and CD between subcoracoid impingement syndrome group and normal group showed significant differences (Z=−9.043, P<0.001; Z=5.981, P<0.001; Z=4.787, P<0.001; Z=−3.731, P<0.001; Z=2.205, P=0.027; Z=3.623, P<0.001; Z=2.233, P=0.026) (Table 2; Figures 1–3).
Table 2.
Comparison of CHD, CI, HLT, CO, CGA, CHA, WST, and CD between normal and subcoracoid impingement syndrome group.
| Normal group | Subcoracoid impingement syndrome group | Z value | P value | |
|---|---|---|---|---|
| CHD (mm) | 7.7±1.5 | 4.7±1.2 | Z=−9.043 | P<0.001 |
| CI (mm) | 16.0±3.3 | 20.1±3.3 | Z=5.981 | P<0.001 |
| HLT (mm) | 5.5±1.0 | 6.6±1.4 | Z=4.787 | P<0.001 |
| CO (°) | 8.9±2.9 | 9.3±3.0 | Z=0.572 | P=0.567 |
| CGA (°) | 132.6±8.5 | 126.8±9.6 | Z=−3.731 | P<0.001 |
| CHA (°) | 106.7±9.5 | 110.2±10.5 | Z=2.205 | P=0.027 |
| WST (mm) | 5.4±1.3 | 6.4±1.8 | Z=3.623 | P<0.001 |
| CD (mm) | 8.9±2.3 | 10.5±3.8 | Z=2.233 | P=0.026 |
The results are expressed as mean±standard deviation (SD); CHD – coracoid-humeral distance; CI – coracoid index; HLT – height of lesser tuberosity; CO – coracoid obliquity; CGA – coracoglenoid angle; CHA – coracohumeral angle; WST – width of the subscapular tendon; CD – contact distance between subscapular tendon and coracoid process.
Figure 1.
The CHD (3.98 mm) of subcoracoid impingement syndrome (A) was narrower than that of the normal shoulder (7.20 mm) (B). (Avanto 1.5T, Siemens; Neusoft PACS software, version 5.5.0.19075, Neusoft). CHD – coracoid-humeral distance.
Figure 2.
The CI (22.17 mm) of subcoracoid impingement syndrome (A) was longer than that of the normal shoulder (15.52 mm) (B). (Avanto 1.5T, Siemens; Neusoft PACS software, version 5.5.0.19075, Neusoft). CI – coracoid index.
Figure 3.
The HLT (7.88 mm) of subcoracoid impingement syndrome (A) was higher than that of normal shoulder (5.74 mm) (B). (Avanto 1.5T, Siemens; Neusoft PACS software, version 5.5.0.19075, Neusoft). HLT – height of lesser tuberosity.
Using a single parameter for diagnosing subcoracoid impingement syndrome, the area under the curve (AUC) of CHD, CI, HLT, CGA, CHA, WST, and CD were 0.963, 0.806, 0.745, 0.691, 0.613, 0.685, and 0.614, respectively (Figure 4), in which CHD showed the largest AUC.
Figure 4.
The ROC curves of CHD, CI, HLT, CGA, CHA, WST, and CD for diagnosing subcoracoid impingement syndrome. (SPSS software, version 26, IBM). ROC – receiver operating characteristic curve; CHD – coracoids-humeral distance; CI – coracoid index; HLT – height of lesser tuberosity; CO – coracoid obliquity; CGA – coracoglenoid angle; CHA – coracohumeral angle; WST – width of the subscapular tendon; CD – contact distance between subscapular tendon and coracoid process.
The parameters (CHD, CI, HLT) with AUC exceeding 0.70 were included in the study of the combined parameters. When the cut-off values were 5.9 mm, 16.5 mm, 5.5 mm for CHD, CI and HLT, respectively, the sensitivity and specificity were 89.4% and 92.0%, 85.1% and 61%, 83% and 57%, respectively. Compared with the AUC using a single CHD for diagnosing subcoracoid impingement syndrome, the combined CHD and CI did not have a significantly different AUC (0.968 vs 0.963, P=0.645), the combined CHD and HLT had a significantly larger AUC (0.986 vs 0.963, P=0.036), and the combined CHD, CI, and HLT also had a significantly larger AUC (0.987 vs 0.963, P=0.022). The AUC of combined CHD and HLT showed no significant difference compared with that of combined CHD, CI, and HLT (0.986 vs 0.987, P=0.882) (Figure 5).
Figure 5.
The ROC curves of combined MRI parameters for diagnosing subcoracoid impingement syndrome. (SPSS software, version 26, IBM). ROC - receiver operating characteristic curve; CHD – coracoids-humeral distance; CI – coracoid index; HLT – height of lesser tuberosity.
Discussion
In summary, CHD, CI, HLT can be used as the efficient quantitative diagnostic indexes of MRI on CIS. Moreover, CHD combined with HLT shows higher efficiency and clinical utility.
Among the parameters in our study, 3 parameters (CHD, CI, HLT) reached the standard of combined parameters analysis, which had AUC exceeding 0.70. The AUC of CHD for diagnosing subcoracoid impingement syndrome in our study was 0.963, which was the largest AUC among all single parameters. Our result on CHD was consistent with some previous studies, which all reported the CHD is the most important index [11,13,24–30]. In our study, CHD was significantly narrower than that of the normal group (4.7 mm vs 7.7 mm), and the cut-off value based on the ROC curve was 5.9 mm. Some studies showed results similar to those of the present study [24–29], although our study showed a larger AUC than the AUC (0.882) reported in a previous study [31].
In our study, the CI also reached the standard of combined parameters analysis, with an AUC of 0.806. There are many anatomic variations in the coracoid process, such as excessive lengthening of the coracoid process, that is, the increase of CI, which is also an important cause of subcoracoid impingement syndrome [3,23,32,33]. The cut-off value in our study was 16.5 mm, which agrees with a past study reporting 16.6 mm as the cut-off value [25].
The HLT was the third parameter included in combined parameters analysis in our study. As some studies reported, variation of small tuberosity anatomy, such as a prominent tuberosity, was one of the causes of impingement [11,15,19,31].
Our study is the first to report that the combined MRI parameters had a better diagnostic effect than a single MRI parameter for diagnosing subcoracoid impingement syndrome. In our study, the combined CHD, CI, and HLT, as well as the combined CHD and HLT, showed significant larger AUCs comparing with CHD alone for diagnosing subcoracoid impingement syndrome. Our study also found the AUC of combined CHD and HLT showed no significant difference compared with that of combined CHD, CI, and HLT. Using as few parameters as possible, the combined CHD and HLT had better clinical utility than combined CHD, CI, and HLT.
Limitations of This Study Are As Follows
First, the sample size of subcoracoid impingement syndrome in this study was not large enough, and future studies should include more cases for detailed analysis. Second, dynamic MRI may have better value for diagnosing subcoracoid impingement syndrome. Third, in this study, the clinical application scanning parameters were used. Although the scanning thickness was slightly thicker, the conclusions of our study can directly guide clinical work.
Conclusions
Measurement of the coracoid-humeral distance and height of the lesser tuberosity were key MRI diagnostic findings for subcoracoid impingement syndrome.
Supplementary Information
Supplementary Table 1.
The MRI sequences and parameters for shoulder.
| Sequence | TR (ms) | TE (ms) | Matrix | Slice thickness (mm) | Section gap (mm) |
|---|---|---|---|---|---|
| Oblique coronal T1-weighted imaging | 687 | 9.40 | 384×384 | 3 | 0.6 |
| Oblique coronal proton-weighted with fat saturation imaging | 4060 | 37 | 320×320 | 3 | 0.6 |
| Axial proton-weighted with fat saturation imaging | 4340 | 27 | 290×320 | 3.5 | 0.8 |
| Axial T1-weighted imaging | 420 | 11 | 384×384 | 3.5 | 0.7 |
| Oblique sagittal T2-weighted with fat saturation imaging | 2790 | 63 | 256×256 | 3 | 0.6 |
MRI – magnetic resonance imaging; TR – repetition time; TE – echo time.
(A) The coracoid-humeral distance (CHD) is defined as the minimal distance between the coracoid process and lesser tuberosity as the double arrow shown on an axial T1-weighted image. (B) The coracoid index (CI) is defined as the distance between coracoid process and glenoid as the double arrow shown on an axial T1-weighted image. (C) The4height of lesser tuberosity (HLT) was defined as distance between the line through the highest point inside and outside the intertubercular sulcus and the parallel line through the bottom of the intertubercular sulcus as the double arrow shown. (D) The coracoid obliquity (CO) was defined as the angle between axis of coracoid process and horizontal line through the apex of coracoid on coronal T1-weighted image. (E) The coracoid-glenoid angle (CGA) was measured as an angle between a line along the plane of the glenoid face and the apex of the coracoid on the axial image. (F)4The coracoid-humeral angle (CHA) was measured as the included angle between the internal and external tangent lines of the humeral head through the tip of the coracoid process on the axial image. (G) The width of the subscapular tendon (WST) is the width of the subscapular tendon measured at the layer with the minimum CHD as the double arrow shown. (H) The contact distance between subscapular tendon and coracoid process (CD) was defined as the distance between superior edge of subscapular tendon and lower edge of coracoid process as the double arrow shown. (Neusoft PACS software, version 5.5.0.19075).
Footnotes
Conflict of interest: None declared
Declaration of Figures’ Authenticity
All figures submitted have been created by the authors, who confirm that the images are original with no duplication and have not been previously published in whole or in part.
Financial support: Gusu Medical Professional Project (GSWS2019020). Nanjing Medical University Project (GSKY20210209)
References
- 1.Rhon DI, Boyles RB, Cleland JA. Management of the unilateral shoulder impingement syndrome. Annals of Internal Medicine. 2015;162(3):237–38. doi: 10.7326/L15-5043-2. [DOI] [PubMed] [Google Scholar]
- 2.Garving C, Jakob S, Bauer I, Nadjar R, Brunner UH. Impingement syndrome of the shoulder. Dtsch Arztebl Int. 2017;114(45):765–76. doi: 10.3238/arztebl.2017.0765. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Asal N, Şahan MH. Radiological variabilities in subcoracoid impingement: Coracoid morphology, coracohumeral distance, coracoglenoid angle, and coracohumeral angle. Med Sci Monit. 2018;24:8678–84. doi: 10.12659/MSM.911470. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Mohammed H, Skalski MR, Patel DB, et al. Coracoid process: The lighthouse of the shoulder. Radiographics. 2016;36(7):2084–101. doi: 10.1148/rg.2016160039. [DOI] [PubMed] [Google Scholar]
- 5.Mulyadi E, Harish S, O’Neill J, Rebello R. MRI of impingement syndromes of the shoulder. Clinical Radiology. 2009;64(3):307–18. doi: 10.1016/j.crad.2008.08.013. [DOI] [PubMed] [Google Scholar]
- 6.Bolia IK, Collon K, Bogdanov J, et al. Management options for shoulder impingement syndrome in athletes: Insights and future directions. Open Access J Sports Med. 2021;12:43–53. doi: 10.2147/OAJSM.S281100. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Lo IK, Burkhart SS. The etiology and assessment of subscapularis tendon tears: A case for subcoracoid impingement, the roller-wringer effect, and TUFF lesions of the subscapularis. Arthroscopy. 2003;19(10):1142–50. doi: 10.1016/j.arthro.2003.10.024. [DOI] [PubMed] [Google Scholar]
- 8.Rossi F. Shoulder impingement syndromes. Eur J Radiol. 1998;27(Suppl 1):S42–48. doi: 10.1016/s0720-048x(98)00042-4. [DOI] [PubMed] [Google Scholar]
- 9.Lazaro R. Shoulder impingement syndromes: Implications on physical therapy examination and intervention. J Jpn Phys Ther Assoc. 2005;8(1):1–7. doi: 10.1298/jjpta.8.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Patte D. The subcoracoid impingement. Clin Orthop Relat Res. 1990;(254):55–59. [PubMed] [Google Scholar]
- 11.Friedman RJ, Bonutti PM, Genez B. Cine magnetic resonance imaging of the subcoracoid region. Orthopedics. 1998;21(5):545–48. [PubMed] [Google Scholar]
- 12.Brunkhorst JP, Giphart JE, LaPrade RF, Millett PJ. Coracohumeral distances and correlation to arm rotation: An in vivo 3-dimensional biplane fluoroscopy study. Orthop J Sports Med. 2013;1(2):2325967113496059. doi: 10.1177/2325967113496059. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Nair AV, Rao SN, Kumaran CK, Kochukunju BV. Clinico-radiological correlation of subcoracoid impingement with reduced coracohumeral interval and its relation to subscapularis tears in Indian patients. J Clin Diagn Res. 2016;10(9):RC17–20. doi: 10.7860/JCDR/2016/23344.8553. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Zhang H, Zhang Q, Li ZL. Coracohumeral index and coracoglenoid inclination as predictors for different types of degenerative subscapularis tendon tears. International Orthopaedics. 2019;43(8):1909–16. doi: 10.1007/s00264-018-4078-5. [DOI] [PubMed] [Google Scholar]
- 15.McKernan MJ, Schickendantz MS, Frangiamore SJ. Diagnosis and management of subcoracoid impingement. J Am Acad Orthop Surg. 2021;29(3):100–7. doi: 10.5435/JAAOS-D-20-00008. [DOI] [PubMed] [Google Scholar]
- 16.Leschinger T, Wallraff C, Müller D, et al. In vivo analysis of coracoid and subacromial shoulder impingement mechanism during clinical examination. Eur J Orthop Surg Traumatol. 2017;27(3):367–72. doi: 10.1007/s00590-017-1919-7. [DOI] [PubMed] [Google Scholar]
- 17.Bergin D, Parker L, Zoga A, Morrison W. Abnormalities on MRI of the subscapularis tendon in the presence of a full-thickness supraspinatus tendon tear. Am J Roentgenol. 2006;186(2):454–59. doi: 10.2214/AJR.04.1723. [DOI] [PubMed] [Google Scholar]
- 18.Halder A, Zobitz ME, Schultz E, An KN. Structural properties of the subscapularis tendon. J Orthop Res. 2000;18(5):829–34. doi: 10.1002/jor.1100180522. [DOI] [PubMed] [Google Scholar]
- 19.Seo JB, Kim SJ, Ham HJ, et al. New predictors for subscapularis tear: Coraco-lesser tuberosity angle, lesser tuberosity angle, and lesser tuberosity height. Orthop Traumat Surg Res. 2020;106(1):45–51. doi: 10.1016/j.otsr.2019.10.017. [DOI] [PubMed] [Google Scholar]
- 20.Watson AC, Jamieson RP, Mattin AC, Page RS. Magnetic resonance imaging based coracoid morphology and its associations with subscapularis tears: A new index. Shoulder Elbow. 2019;11(1 Suppl):52–58. doi: 10.1177/1758573217744170. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Radas CB, Pieper HG. The coracoid impingement of the subscapularis tendon: A cadaver study. J Shoulder Elbow Surg. 2004;13(2):154–59. doi: 10.1016/j.jse.2003.12.007. [DOI] [PubMed] [Google Scholar]
- 22.Tan V, Moore RS, Jr, Omarini L, et al. Magnetic resonance imaging analysis of coracoid morphology and its relation to rotator cuff tears. Am J Orthop (Belle Mead, NJ) 2002;31(6):329–33. [PubMed] [Google Scholar]
- 23.Cetinkaya M, Ataoglu MB, Ozer M, et al. Subscapularis tendon slip number and coracoid overlap are more related parameters for subcoracoid impingement in subscapularis tears: A magnetic resonance imaging comparison study. Arthroscopy. 2017;33(4):734–42. doi: 10.1016/j.arthro.2016.09.003. [DOI] [PubMed] [Google Scholar]
- 24.Gerber C, Terrier F, Ganz R. The role of the coracoid process in the chronic impingement syndrome. J Bone Joint Surg Br. 1985;67(5):703–8. doi: 10.1302/0301-620X.67B5.4055864. [DOI] [PubMed] [Google Scholar]
- 25.Leite MJ, Sá MC, Lopes MJ, et al. Coracohumeral distance and coracoid overlap as predictors of subscapularis and long head of the biceps injuries. J Shoulder Elbow Surg. 2019;28(9):1723–27. doi: 10.1016/j.jse.2019.01.012. [DOI] [PubMed] [Google Scholar]
- 26.Richards DP, Burkhart SS, Campbell SE. Relation between narrowed coracohumeral distance and subscapularis tears. Arthroscopy. 2005;21(10):1223–28. doi: 10.1016/j.arthro.2005.06.015. [DOI] [PubMed] [Google Scholar]
- 27.Misirlioglu M, Aydin A, Yildiz V, et al. Prevalence of the association of subacromial impingement with subcoracoid impingement and their clinical effects. J Int Med Res. 2012;40(2):810–15. doi: 10.1177/147323001204000248. [DOI] [PubMed] [Google Scholar]
- 28.Richards DP, Burkhart SS, Campbell SE. Relation between narrowed coracohumeral distance and subscapularis tears. Arthroscopy. 2005;21(10):1223–28. doi: 10.1016/j.arthro.2005.06.015. [DOI] [PubMed] [Google Scholar]
- 29.Balke M, Banerjee M, Greshake O, et al. The coracohumeral distance in shoulders with traumatic and degenerative subscapularis tendon tears. Am J Sports Med. 2016;44(1):198–201. doi: 10.1177/0363546515611653. [DOI] [PubMed] [Google Scholar]
- 30.Giaroli EL, Major NM, Lemley DE, Lee J. Coracohumeral interval imaging in subcoracoid impingement syndrome on MRI. Am J Roentgenol. 2006;186(1):242–46. doi: 10.2214/AJR.04.0830. [DOI] [PubMed] [Google Scholar]
- 31.Zhu S, Tan J, Wu D, et al. Bilateral coracohumeral distance discrepancy is associated with subscapularis tear in rotator cuff rupture patients. Knee Surg Sports Traumatol Arthrosc. 2021;29(12):3936–42. doi: 10.1007/s00167-021-06597-6. [DOI] [PubMed] [Google Scholar]
- 32.Garofalo R, Conti M, Massazza G, et al. Subcoracoid impingement syndrome: A painful shoulder condition related to different pathologic factors. Musculoskelet Surg. 2011;95(Suppl 1):S25–29. doi: 10.1007/s12306-011-0142-7. [DOI] [PubMed] [Google Scholar]
- 33.Leite MJ, Pinho AR, Sá MC, et al. Coracoid morphology and humeral version as risk factors for subscapularis tears. J Shoulder Elbow Surg. 2020;29(9):1804–10. doi: 10.1016/j.jse.2020.01.074. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Supplementary Table 1.
The MRI sequences and parameters for shoulder.
| Sequence | TR (ms) | TE (ms) | Matrix | Slice thickness (mm) | Section gap (mm) |
|---|---|---|---|---|---|
| Oblique coronal T1-weighted imaging | 687 | 9.40 | 384×384 | 3 | 0.6 |
| Oblique coronal proton-weighted with fat saturation imaging | 4060 | 37 | 320×320 | 3 | 0.6 |
| Axial proton-weighted with fat saturation imaging | 4340 | 27 | 290×320 | 3.5 | 0.8 |
| Axial T1-weighted imaging | 420 | 11 | 384×384 | 3.5 | 0.7 |
| Oblique sagittal T2-weighted with fat saturation imaging | 2790 | 63 | 256×256 | 3 | 0.6 |
MRI – magnetic resonance imaging; TR – repetition time; TE – echo time.
(A) The coracoid-humeral distance (CHD) is defined as the minimal distance between the coracoid process and lesser tuberosity as the double arrow shown on an axial T1-weighted image. (B) The coracoid index (CI) is defined as the distance between coracoid process and glenoid as the double arrow shown on an axial T1-weighted image. (C) The4height of lesser tuberosity (HLT) was defined as distance between the line through the highest point inside and outside the intertubercular sulcus and the parallel line through the bottom of the intertubercular sulcus as the double arrow shown. (D) The coracoid obliquity (CO) was defined as the angle between axis of coracoid process and horizontal line through the apex of coracoid on coronal T1-weighted image. (E) The coracoid-glenoid angle (CGA) was measured as an angle between a line along the plane of the glenoid face and the apex of the coracoid on the axial image. (F)4The coracoid-humeral angle (CHA) was measured as the included angle between the internal and external tangent lines of the humeral head through the tip of the coracoid process on the axial image. (G) The width of the subscapular tendon (WST) is the width of the subscapular tendon measured at the layer with the minimum CHD as the double arrow shown. (H) The contact distance between subscapular tendon and coracoid process (CD) was defined as the distance between superior edge of subscapular tendon and lower edge of coracoid process as the double arrow shown. (Neusoft PACS software, version 5.5.0.19075).