Can knees kneel? Kneeling ability after total, unicompartmental and patellofemoral knee arthroplasty.

This study investigates patients' perception of kneeling ability before and at 1 and 2 years after total, unicompartmental knee replacement (UKR) and patellofemoral knee replacement (PFR), for osteoarthritis. Kneeling is an important function of the knee joint required for many daily activities and inability to kneel after knee surgery is a frequent cause of dissatisfaction. Data were prospectively collected on 253 knees. A kneeling score was obtained by analysis of the relevant section of the Oxford knee score. Scores were obtained pre-operatively and at 1 and 2 years post-operatively. Absolute values and change following surgery were recorded. Correlations with pain and other knee functions were also made. Kneeling ability prior to surgery was poor in all 3 groups (80% found it extremely difficult or impossible to kneel) and improved in all groups after surgery (20% had little or no difficulty to kneel at 2 years). Kneeling ability was best in UKR and worst in PFR. These results suggest that kneeling ability in osteoarthritic patients is poor but improves with knee arthroplasty surgery, however the majority of patients will still have difficulty in kneeling.