Medial Tibial Condylar Valgus Osteotomy improve clinical outcomes and effectively corrects significant Tibial varus deformities without compromising joint line obliquity or patellar heigh.

Abstract

Background: Tibial condylar valgus osteotomy (TCVO), or Chiba osteotomy, is a recognized procedure for treating advanced knee osteoarthritis in middle-aged individuals. Although its effectiveness is established, limited literature exists on its outcomes for specific conditions such as post-traumatic deformities, Blount disease (BD), and Pagoda-like proximal tibia varus deformities.

Hypothesis: We hypothesized that TCVO could improve both clinical and radiographic outcomes in patients with severe varus deformities, correcting lower-limb variances while preserving joint line obliquity (JLO) and patellar height in substantial varus deformities.

Patients and methods: This study included 33 patients who underwent TCVO, with etiologies including post-traumatic (26 patients, 78.8%), Blount disease (4 patients, 12.1%), and Pagoda deformities (3 patients, 9.1%). The average age was 32.5 years (standard deviation = 12.8 years). Techniques for deformity correction varied, including Patient Specific Instrumentation (PSI) for 10 patients (30.3%) and locking plate fixation for 13 patients (39.4%). We assessed several radiological parameters such as hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), Caton-Deschamps index (CDI), and proximal posterior tibial angle (PPTA). Patient-reported outcomes, including the Knee injury and Osteoarthritis Outcome Score (KOOS) and simple knee value (SKV), were recorded both pre-operatively and two years post-operatively.

Results: Statistically significant improvements were observed in clinical scores and alignment changes two years post-operatively, including increases in HKA (from 166.1 to 178.4, p < .0001) and MPTA (from 72.4 to 85.1, p < .0001), and a decrease in JLO (from 9.8 to 3.2, p < .0001). No significant changes were noted in JLCA, PPTA, and CDI, with the patellar height remaining stable post-operatively. The achieved corrections closely matched the pre-operative plans.

Conclusion: TCVO offers significant improvements in radiological and clinical parameters for patients with substantial tibial varus deformities, effectively maintaining JLO and patellar height. Optimal outcomes from TCVO are dependent on careful patient selection and precise execution of surgical techniques.

Level of evidence: III.