Medial femoral condyle restoration technique in total knee arthroplasty

To introduce a medial femoral condyle restoration (MFCR) technique for total knee arthroplasty (TKA) and compare its clinical outcomes with conventional mechanical alignment (MA) in varus osteoarthritis.

In this prospective randomized trial, 126 consecutive patients with varus osteoarthritis undergoing TKA (January 2021-January 2023) were assigned to MFCR or MA. MFCR surgical key points were medially focused quantitative compensation of cartilage loss by reducing distal/posterior medial femoral resections using thickness-specific shims (0.5-2.0 mm, 0.5-mm steps) guided by Outerbridge grading and calibrated probing. Participants were randomized to receive either the MFCR technique or the conventional MA technique. Intraoperative outcomes (blood loss, operative time, hospital stay, and medial release) and postoperative ROM were recorded; functional outcomes included WOMAC and walking VAS pain. Continuous variables were expressed as mean ± standard deviation and analyzed using one-way analysis of variance.

The mean age of the MFCR group and control group was 68.3 ± 7.4 years and 67.9 ± 8.7 years, respectively (P = 0.4236). Preoperatively, the mean WOMAC score of the groups was 67.2 ± 9.8 and 62.3 ± 16.4, respectively (P = 0.2524). The mean varus knee angle was 18.2° ± 7.2° and 17.3° ± 8.9°, respectively (P = 0.6735). The mean time for soft tissue balancing was 5.1 ± 2.6 min and 12.1 ± 4.3 min in the MFCR and control group, respectively (P = 0.017). The mean operative time was 50.6 ± 12.1 min and 58.9 ± 13.8 min in the MFCR and control group, respectively (P = 0.011). The mean hospital stay time was 1.8 ± 0.7 days and 3.2 ± 0.9 days in the MFCR and control group, respectively (P = 0.028). At 2 years postoperatively, the WOMAC scores were 29.9 ± 17.9 and 43.6 ± 13.7, respectively (P = 0.0325). Postoperative nausea/vomiting occurred less frequently in the MFCR group (P = 0.0391), with no other complications observed during follow-up.

MFCR restored the anatomy of the medial femoral condyle by quantitatively preserving medial femoral bone to compensate for cartilage loss within a bony-first, minimal-release workflow. Compared with MA, MFCR reduced perioperative burden and improved early function, and can be implemented using a simple, reproducible technique without advanced imaging or robotics. Video Abstract.