Roentgenographic and Clinical Findings of Patellofemoral Osteoarthrosis

Abstract

In order to determine definitive clinical and roentgenographic findings of patellofemoral osteoarthrosis (PF-OA) and the etiologic factors of this disease as well as its relationship to femorotibial osteoarthrosis (FT-OA), 108 knees having moderate to severe PF-OA with or without FT-OA were investigated. Pain and disabilities of activities of daily living (ADL) due to PF-OA most likely appeared during movements requiring deep flexion of the knee. Roentgenographic findings revealed a great majority of the disease occurred on the lateral side of the PF joint, both in cases of PF-OA alone and in PF-OA combined with FT-OA. There was no relationship between the degree of PF-OA advancement determined by roentgenographic findings and that of ADL disabilities. PF-OA and FT-OA seemed to be caused by different etiologic factors, because the degrees of involvement of the PF and FT joints were not correlated with each other in the cases of PF-OA combined with FT-OA. Since a clear history of dislocation or subluxation of the patella was noted in 18% of PF-OA (this figure increased to 28% if limited to the cases affected with PF-OA alone), and since roentgenographic findings also agreed with this evidence, dislocation or subluxation of the patella seemed to be one of the causes of PF-OA.