The vastus medialis oblique muscle and its relationship to patellofemoral joint deterioration in human cadavers.

Abstract

Patellofemoral joint deterioration (PFJD) is frequently seen in physical therapy clinics and represents a significant problem for both patients and rehabilitation clinicians. The vastus medialis oblique (VMO) muscle is reported to be the primary stabilizer of the patella during knee extension. Most studies and treatment protocols emphasize strengthening of the VMO as the nonsurgical treatment of choice for patients with PFJD. The purpose of this study was to determine whether any relationship exists between the morphology of the VMO and the presence and severity of PFJD in human cadavers. Dissection of 374 vastus medialis (VM) muscles and patellofemoral joints was performed on 229 human cadaver lower limbs to determine what relationships exist between gender, VMO features, and PFJD. Patellofemoral joint deterioration was determined by direct visual observation and assigned a score based on severity of joint deterioration present. Two-way chi-square tests were performed to determine the relationships between cadaver gender, the presence of VMO features, and the presence and severity of PFJD. Linear regression was performed to determine whether any correlation existed between the VMO fiber angle and the severity of PFJD. A one-way analysis of variance was performed to determine whether any differences existed between the VMO fiber angle and the PFJD groups. No statistically significant relationships, correlation, or differences existed in any of the tests performed between cadaver gender, VMO features, and presence or severity of PFJD. The presence or severity of PFJD in human cadavers is not related to either gender or VMO morphologic features. The results of this study do not support the premise that a more distal insertion of the VMO onto the patella of the VMO will have any effect on the presence or severity of PFJD.