Morphologic changes in the vastus medialis muscle in patients with osteoarthritis of the knee.

TY - JOUR

T1 - Morphologic changes in the vastus medialis muscle in patients with osteoarthritis of the knee.

AU - Fink, Bernd

AU - Egl, Monika

AU - Singer, Joachim

AU - Fuerst, Martin

AU - Bubenheim, Michael

AU - Neuen-Jacob, Eva

PY - 2007

Y1 - 2007

N2 - OBJECTIVE: To investigate the frequency of structural changes in the vastus medialis muscle in patients with osteoarthritis (OA) of the knee. METHODS: Specimens of vastus medialis muscle from 78 patients with end-stage OA of the knee undergoing total joint arthroplasty were examined histopathologically. Morphologic changes were assessed in relation to clinical features that might have contributed to muscle injury. RESULTS: All muscle specimens exhibited atrophy of type 2 fibers. In 32% of the patients, atrophy of type 1 fibers was also noted. Fiber type grouping of type 1 fiber in 15% of the patients and type 2 fiber in 37%, indicating reinnervation, led to the diagnosis of neurogenic muscular atrophy in 32% of the patients; selective atrophy of type 2 fiber in 68% of the specimens was interpreted as possibly resulting from pain-associated disuse. Signs of muscle degeneration and regeneration were found in 65% and 96% of the samples, respectively. Soft tissue changes indicating long-term disease, such as calcification, fibrosis, and lipomatosis, were frequently observed (in 69%, 71%, and 94% of the patients, respectively). Statistical analysis of clinical and morphologic parameters revealed a significant association between degenerative muscle changes and the presence of a varus deviation of the leg axis. CONCLUSION: Patients with OA of the knee frequently exhibit muscle changes, with probable multifactorial etiology. Selective atrophy of type 2 fibers might reflect pain-related immobilization of a limb. Changes such as neurogenic muscular atrophy, muscle fiber degeneration, and regeneration might contribute as cofactors in the development or progression of OA.

AB - OBJECTIVE: To investigate the frequency of structural changes in the vastus medialis muscle in patients with osteoarthritis (OA) of the knee. METHODS: Specimens of vastus medialis muscle from 78 patients with end-stage OA of the knee undergoing total joint arthroplasty were examined histopathologically. Morphologic changes were assessed in relation to clinical features that might have contributed to muscle injury. RESULTS: All muscle specimens exhibited atrophy of type 2 fibers. In 32% of the patients, atrophy of type 1 fibers was also noted. Fiber type grouping of type 1 fiber in 15% of the patients and type 2 fiber in 37%, indicating reinnervation, led to the diagnosis of neurogenic muscular atrophy in 32% of the patients; selective atrophy of type 2 fiber in 68% of the specimens was interpreted as possibly resulting from pain-associated disuse. Signs of muscle degeneration and regeneration were found in 65% and 96% of the samples, respectively. Soft tissue changes indicating long-term disease, such as calcification, fibrosis, and lipomatosis, were frequently observed (in 69%, 71%, and 94% of the patients, respectively). Statistical analysis of clinical and morphologic parameters revealed a significant association between degenerative muscle changes and the presence of a varus deviation of the leg axis. CONCLUSION: Patients with OA of the knee frequently exhibit muscle changes, with probable multifactorial etiology. Selective atrophy of type 2 fibers might reflect pain-related immobilization of a limb. Changes such as neurogenic muscular atrophy, muscle fiber degeneration, and regeneration might contribute as cofactors in the development or progression of OA.

M3 - SCORING: Zeitschriftenaufsatz

VL - 56

SP - 3626

EP - 3633

JO - ARTHRITIS RHEUMATOL

JF - ARTHRITIS RHEUMATOL

SN - 2326-5191

IS - 11

M1 - 11

ER -