Magnetic resonance imaging of patellofemoral osteoarthritis: intertester reliability and associations with knee pain and function

Abstract

Objectives

We examined the intertester reliability of patellofemoral compartment (PFC) osteoarthritis (OA) severity using magnetic resonance images (MRI) and a modified Kellgren and Lawrence (K&L) system. Second, we determined if these grades were associated with clinical tests of PFC involvement or self-reported pain/difficulty with stair climbing. Third, we assessed the association between PFC OA severity and knee pain or disability, after accounting for potential confounders including tibiofemoral OA severity.

Method

We examined the 9-year Osteoarthritis Initiative data from 114 subjects in the year prior to undergoing knee arthroplasty. The weighted kappa (κ_w) was used to determine intertester reliability, and the Pearson chi-square was used to assess associations among PFC OA scores and clinical tests. Multiple regressions were used to determine independent associations between self-reported pain/function and PFC OA.

Results

Reliability was substantial (κ_w = 0.73 (SE = 0.05)). Chi-square associations between PFC OA severity and clinical tests were not significant (p > 0.05). Multiple regression models between PFC OA and self-reported pain or function scores were not significant (p > 0.05).

Conclusions

MRI-based measures of PFC OA were highly reliable indicating that musculoskeletal radiologists can reliably grade the PFCs of subjects using MRI. The extent of PFC OA is not associated with either clinical tests of PFC involvement or activities associated with PFC pain in persons with moderate to severe symptomatic tibiofemoral and PFC OA.

http://bit.ly/2C46VBu