[Patellofemoral joint dynamics in patients with gonarthrosis]

Although the tibiofemoral joint has been evaluated in most of the gonarthrosis studies, the relationships between gonarthrosis and the patellofemoral joint have usually been disregarded. In this study, the dynamics of the patellofemoral joint in gonarthrosis has been evaluated.

Dynamic and kinematic axial computed tomography scans were obtained in 33 knees of 22 patients (19 females, 3 males; mean age 67.0 +/-3.2; range 58 to 75 years) who were scheduled for total knee arthroplasty due to the gonarthrosis. The control group consisted of 28 knees of 14 normal volunteers (11 females, 3 males; mean age 25 +/- 4.6; range 10 to 46 years) without any knee complaints or disorders. Sulcus, congruence and patellar tilt angles were measured on axial images which were obtained in different flexion angles of the knee (0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees and 60 degrees), both with and without contraction of the quadriceps muscle. ANOVA and paired-t tests were used for statistical analysis.

Patellar tilt increased significantly in gonarthrotic patients compared to the controls (p < 0.05). The congruence angle was significantly lower in patients at 0 degrees and 10 degrees of knee flexion, but higher at 20 degrees, 30 degrees, 40 degrees and 60 degrees than controls (p < 0.05). The congruence angle increased significantly with the contraction of the quadriceps in controls, but no significant changes were observed in patients.

Dynamics of the patellofemoral joint is different in patients with gonarthrosis than normal volunteers. Patellofemoral complaints following knee arthroplasties may be related to these differences.