Purpose A modified technique, medial indentation of the medial collateral ligament(MCL),was usedin total kneearthroplastywith severe type II valgus deformity. The study compared the clinical outcomes of the technique relative to conventional release group.
Methods Consecutive patients with a Krackow type II valgus deformity of >20° who underwent a primary unilateral TKA between May 2008 and June 2017 were retrospectively studied. Modified MCL indentation technique was performed in 20 patients (group A), while the remaining 23 patients (group B) received routine release technique. Radiological parameters, such as the valgus angle (VA), and functional outcomes including the use of constraint implants, Knee Society Score(KSS), Knee Society function score(KSF), and height of the polyethylene insert, were compared between the two groups.
Results 43 consecutive patients had a minimum 2-year follow-up. The preoperative VA was comparable between group A (23.5° ± 5.8°) and group B (21.3° ± 3.2°, P =0.134), so was the postoperative VA (1.1° ± 2.1° and 2.5° ± 3.0°, P =0.084 in groups A and B, respectively).The postoperative KSS and KSF showed marked improvement. While no statistically significant difference in preoperative or postoperative functional scores was found between two groups, group A had thinner PE insert (9.5 ± 1.1 mm vs. 12.9 ± 1.5 mm) and less use of constrained condylar inserts(15% vs. 69.6%).
Conclusion Modified MCL indentation technique can achieve good outcomes in TKA with type II valgus deformity of >20°.