An age- and gender-related three-dimensional analysis of rotator cuff transverse force couple volume ratio in 304 shoulders.
OBJECTIVE
The rotator cuff transverse force couple (RCTFC) is fundamental in the shoulder biomechanics, as the balance of its muscle components (the subscapularis relative to the infraspinatus and teres minor) provides stability to the joint. The chronic progression of rotator cuff tears usually present alterations in muscle volume, along with atrophy and compensatory hypertrophy, which can be determined using imaging techniques. The aim of this study was to quantify RCTFC muscle volume in a large sample taking into account the age and gender of the participants involved.


METHODS
An observational, retrospective, cross-sectional, descriptive and comparative study was conducted, evaluating thoracic computed tomography scans from 152 patients (304 shoulders) of indistinct gender, with ages ranging between 18 and 85 years. The RCTFC muscle volume was quantified with an oblique/multiplanar segmentation technique. Measuring time was also documented.


RESULTS
We observed that muscle volume decreases among the different age (p < 0.04) and gender (p < 0.001) groups. However, the RCTFC volume ratio remained constant at 1.02 ± 0.18 without significant differences throughout all age and gender groups evaluated (p > 0.298).


CONCLUSIONS
The decrease in the RCTFC muscle volume is proportional during the different stages of life, maintaining a constant ratio between its components (physiological RCTFC muscle atrophy). The time-saving segmentation method and volume ratio formula proposed in this study contribute to the management and understanding of rotator cuff tear/pathology.
Department of Human Anatomy, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Avenida Francisco I. Madero y Gonzalitos s/n Colonia Mitras Centro, C.P. 64460, Monterrey, Nuevo León, Mexico.
Abraham Guadalupe
AG
Espinosa-Uribe
Department of Radiology and Imaging, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Monterrey, Nuevo León, Mexico.
Adrian Antonio
AA
Negreros-Osuna
Department of Human Anatomy, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Avenida Francisco I. Madero y Gonzalitos s/n Colonia Mitras Centro, C.P. 64460, Monterrey, Nuevo León, Mexico.
Jorge
J
Gutierréz-de la O
Department of Orthopedics and Traumatology, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Monterrey, Nuevo León, Mexico.
Félix
F
Vílchez-Cavazos
Department of Radiology and Imaging, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Monterrey, Nuevo León, Mexico.
Ricardo
R
Pinales-Razo
Department of Human Anatomy, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Avenida Francisco I. Madero y Gonzalitos s/n Colonia Mitras Centro, C.P. 64460, Monterrey, Nuevo León, Mexico.
Alejandro
A
Quiroga-Garza
Department of Radiology and Imaging, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Monterrey, Nuevo León, Mexico.
Guillermo
G
Elizondo-Riojas
Department of Human Anatomy, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Avenida Francisco I. Madero y Gonzalitos s/n Colonia Mitras Centro, C.P. 64460, Monterrey, Nuevo León, Mexico. rod_omana@yahoo.com.
Rodrigo Enrique
RE
Elizondo-Omaña
Department of Human Anatomy, Faculty of Medicine and University Hospital "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León (U.A.N.L.), Avenida Francisco I. Madero y Gonzalitos s/n Colonia Mitras Centro, C.P. 64460, Monterrey, Nuevo León, Mexico.
Santos
S
Guzmán-López
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000503:physiopathology*; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000473:pathology; D000070636:Rotator Cuff Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012737:Sex Factors; D012785:Shoulder Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000503:physiopathology; D014057:Tomography, X-Ray Computed; D055815:Young Adult
Age; Muscle volume; Rotator cuff; Segmentation; Transverse force couple