Can We Predict Kneeling after Knee Replacement

Background: Over 90,000 knee replacements are performed annually in the NHS in increasingly younger patients with high functional demands. Patient satisfaction following this surgery continues to vary. Kneeling is a basic human function and is required in certain employments, religious worship, as part of cultural norms and in pursuit of recreation and routine daily activity. This study set out to identify simple patient factors that could predict kneeling in patients undergoing either total (TKR) or partial knee replacement (PKR). Materials and Methods: 162 patients (80 TKR, 82 PKR) were identified from the departmental database. Factors assessed included; range of movement, body mass index (BMI), oxford knee score (OKS) and kneeling ability (question 7 of OKS). Correlation and regression analysis were performed to identify association and prediction of kneeling at 12 months follow up. Results: Kneeling ability and overall function improved in both groups. Preoperative kneeling ability, BMI, comorbidity and postoperative range of movement correlated most closely with final kneeling ability in the TKR group. Similar findings were demonstrated in the PKR group. Successful kneeling after knee replacement was best predicted by the ability to do so preoperatively. Fixed flexion deformity negatively predicted kneeling after PKR. Conclusion: Tailoring preoperative counselling to the individual patient is vital. The use of a simple preoperative ability to kneel or the presence of a fixed flexion contracture may aid the treating surgeon to better inform of postoperative kneeling to an individual patient considering knee replacement surgery.