Intra-articular osteotomies for medial compartment osteoarthritis: Is adding an extra-articular osteotomy worthwhile?

Abstract

Background and Aims: Medial compartment osteoarthritis (MCOA) of the knee presents with varus deformity arising from the upper tibia or lower femur. High tibial osteotomies relieve pain by correcting the varus and improving the mechanical axis deviation (MAD). Closing wedge, opening wedge, and dome osteotomies are popular choices in the upper tibial metaphysis. These are all extra-articular osteotomies (EAO). Recently, attention has turned to detection and treatment of intra articular deformity arising from the knee to treat MCOA. Tibial condylar valgus osteotomy (TCVO) is an intra-articular osteotomy (IAO) which corrects the varus malalignment by elevating the medial tibial condyle and is usually fixed with a plate (Tibial condylar valgus osteotomy-plating [TCVO-P]). A second distal extra articular osteotomy, fixed with an Ilizarov fixator (tibial condylar valgus osteotomy-Ilizarov [TCVO-I]) is performed in some patients for better correction of the mechanical axis. The two groups were treated with different surgical approaches based on preoperative analysis of deformity. Hence this is a level IV study. We aimed to study the improvement in radiological parameters after TCVO in MCOA. We also compared the results between TCVO-P and TCVO-I. Patients and Methods: We performed 64 osteotomies in 55 patients over the last 7 years. 30 (33 tibiae) had a TCVO-P. 25 (31 tibiae) had a TCVO-I. The mean age in TCVO-P was 55 years, and in TCVO-I was 48 years. Results: The mean preoperative (bo) MAD was more in TCVO-I at –37.4% and improved to a mean postoperative MAD of 53.8%. TCVO-P had a lesser mean bo MAD of –7.4%, which corrected to 46.4%. MAD was better corrected by TCVO-I (P = 0.0058). Correction of medial proximal tibial angle, hip knee ankle angle, ankle joint line orientation improved significantly in both groups. The knee joint line orientation was improved by TCVO-I (P = 0.001), but not by TCVO-P (P = 0.075). Joint line convergence angle (JLCA), spine edge angle, and spine vertical distance were all significantly improved in both groups. Condylar plateau angle was not changed significantly in either group. Conclusion: TCVO is an Intra articular osteotomy which effectively corrects the varus deformity arising from the knee joint in MCOA. An isolated TCVO-P slightly under-corrects the mechanical axis. TCVO-I is better at restoring mechanical axis to beyond neutral and is better for younger patients and with intorsion deformities.