Short-term safety and efficacy of a novel high tibial osteotomy system: a case controlled study

To evaluate the safety and efficacy of the novel iBalance Medial Opening Wedge High Tibial Osteotomy (HTO) system in executing lower limb realignment in patients with symptomatic varus gonarthrosis. A multicentre case series of iBalance medial opening wedge HTO was compared to an historic case-matched control series of HTO's performed using another implant. Subjects were prospectively observed at 3, 6 and 12 months after surgery. Primary endpoints included the reporting of adverse events, weight-bearing status without pain and radiographic evidence of bony union. Secondary endpoints included maintenance of osteotomy correction angle, patient reported outcome (KOOS and SF-36) and gait analysis. Thirty-two consecutive patients were included in the iBalance group (mean age 49.7, 30-67; M:F, 20:12), paired with 32 control subjects (49.8, 35-66; 21:11). Three patients (9.4%) in the iBalance group experienced a complication requiring intervention versus one patient (3.1%) in the control group. No statistically significant differences were seen between groups in terms of time to weight bearing, radiographic union, implant stability or patient reported outcome. Gait analysis revealed a statistically significant reduction in knee external adduction moment (P < 0.001). The iBalance medial opening wedge HTO system has been shown to be a safe, novel implant for use in proximal tibial osteotomy. This study shows that the iBalance medial opening wedge HTO system has an equivalent short-term safety and efficacy profile to the 2nd generation Puddu system.