Comparative study of high tibial osteotomy using dynamic axial fixator and locked low-profile plate in medial osteoarthritis of knee.

purposeThe purpose of this study was to evaluate the role of medial opening wedge high tibial osteotomy (HTO) in medial unicompartmental osteoarthritis (MCOA) of knee and to compare between the two methods of osteotomy using either dynamic axial fixator (DAF) or locking compression plate (LCP).

methodsA total of 20 patients with medial osteoarthritis of knee were enrolled in this prospective study who were divided into two groups of 10 each. First group comprising of two males and eight females were treated by HTO using DAF. Second group comprising of five males and five females were treated by HTO using LCP. We assessed various radiological parameters including hip knee ankle angle (HKA), tibiofemoral angle (TFA), weight-bearing line on tibia, Insall Salvati index and tibial slope. Functional outcome of knee at final follow-up was assessed by Oxford knee score (OKS) and visual analogue scale.

resultsIn first group, mean HKA angle changed from 187° to 178.30° (p = 0.006), mean TFA from 182.40° to 172° (p = 0.003), average position of weight-bearing line from 11.24 to 59.54 % (p = 0.004), and mean OKS 43.3-16.9 (p = 0.004). In second group, mean HKA angle changed from 186° to 178.80° (p = 0.004), mean TFA from 180.90° to 173.60° (p = 0.004), average position of weight-bearing line from 14 to 61.3 % (p = 0.004), and mean OKS 43.2-16.5 (p = 0.002).

conclusionHTO is an established treatment for patients with symptomatic MCOA knee with significant improvement in the clinical and radiographic parameters. There is no significant difference between the two methods; however, external fixator has the complication of pin tract infections. LEVEL OF EVIDENCE: II.