In primary total knee arthroplasty, measured resection provides greater external femoral rotational alignment but no clinically relevant difference compared to gap balancing: a radiographic and clinical 7-year study

BACKGROUND: In total knee arthroplasty (TKA), malrotation of the femoral component has been associated with postoperative pain and patient dissatisfaction. Two main surgical techniques are commonly used to perform TKA: measured resection (MR) and gap balancing (GB). However, it is still debated which technique provides more accurate femoral component rotation and better clinical outcomes.METHODS: Fifty patients with symptomatic primary knee osteoarthritis were included. Twenty-five patients underwent TKA using the MR technique and 25 using the GB technique. Preoperative and postoperative CT scans were performed to assess femoral rotational alignment. Clinical outcomes were evaluated using the Knee Society Score (KSS), Functional Knee Society Score (FKSS), and WOMAC score preoperatively and at 6 months, 1, 3, 5, and 7 years postoperatively.RESULTS: The mean postoperative femoral component alignment was +3° in the MR group and +0.48° in the GB group (P=0.005). No statistically significant differences were observed between the two groups in any of the clinical outcome scores at all follow-up time points.CONCLUSIONS: Both MR and GB techniques resulted in excellent long-term clinical outcomes. Although the MR technique showed a tendency toward greater external femoral component rotation, this did not translate into clinically relevant differences.