Effects of post-fracture non-weight-bearing immobilization on muscle atrophy, intramuscular and intermuscular adipose tissues in the thigh and calf

• Published in: Skeletal radiology 2018-11, Vol.47 (11), p.1541-1549
• Main Authors: Yoshiko, Akito, Yamauchi, Koun, Kato, Takayuki, Ishida, Koji, Koike, Teruhiko, Oshida, Yoshiharu, Akima, Hiroshi
• Format: Article
• Language: English
• Subjects: Adipose tissue; Adipose Tissue - diagnostic imaging; Adipose Tissue - pathology; Adipose tissues; Aged; Aged, 80 and over; Ankle; Atrophy; Casts, Surgical; Crutches; Female; Fibula - injuries; Fractures; Fractures, Bone - therapy; Humans; Imaging; Immobilization; Immobilization - adverse effects; Leg; Magnetic Resonance Imaging; Male; Medical research; Medicine; Medicine & Public Health; Medicine, Experimental; Metatarsal Bones - diagnostic imaging; Metatarsal Bones - injuries; Metatarsus; Middle Aged; Muscle, Skeletal - diagnostic imaging; Muscle, Skeletal - pathology; Muscles; Muscular Disorders, Atrophic - diagnostic imaging; Muscular Disorders, Atrophic - etiology; Muscular Disorders, Atrophic - pathology; Musculoskeletal system; Nuclear Medicine; Orthopedics; Pathology; Plaster casting; Radiology; Scientific Article; Skeletal muscle; Statistical analysis; Thigh; Type 2 diabetes; Weight-Bearing
• ISSN: 0364-2348; 1432-2161
• DOI: 10.1007/s00256-018-2985-6

Objective Disuse and/or a non-weight-bearing condition changes muscle composition, with decreased skeletal muscle tissue and increased fat within (intramuscular adipose tissue, IntraMAT) and between (intermuscular adipose tissue, InterMAT) given muscles. Excessive adipose tissue contributes to dysfunctional and metabolically impaired muscle. How these adipose tissues change during orthopedic treatment (e.g., cast immobilization, daily use of crutches) is not well documented. This study aimed to quantify changes in IntraMAT, InterMAT, and thigh and calf muscle tissue during orthopedic treatment. Materials and methods We studied 8 patients with fifth metatarsal bone or fibular fractures. The ankle joint involved underwent plaster casting for approximately 4 weeks, with crutches used during that time. Axial T1-weighted MRI at the mid-thigh and a 30% proximal site at the calf were obtained to measure IntraMAT and InterMAT cross-sectional areas (CSAs) and skeletal muscle tissue CSA before treatment and 4 weeks afterward. Results Thigh and calf muscle tissue CSAs were significantly decreased from before to after treatment: thigh, 85.8 ± 7.6 to 77.1 ± 7.3 cm 2 ; calf, 53.3 ± 5.5 to 48.9 ± 5.0 cm 2 ( p