Prospective evaluation of a new plate fixator for valgus-producing medial open-wedge high tibial osteotomy.

PURPOSE: The purpose of this study was to prospectively evaluate the clinical, radiographic, and sports-related outcome at 24 months after valgus-producing medial open-wedge high tibial osteotomy (owHTO) using a 2nd generation peek-carbon composite plate.
METHODS: Between 2010 and 2011, the 2nd generation PEEKPower HTO-Plate(®) was used for medial owHTO in 28 consecutive patients (19 men, 9 women; mean age ± SD: 45 ± 11 years; mean varus deviation ± SD: 4° ± 2°). All of the patients had an osteotomy gap height of ≤12 mm without bone grafting. Visual analog scale (VAS) for pain, WOMAC score, and Lysholm score were evaluated preoperatively and at 12 and 24 months postoperatively. Sports-related outcomes included the Tegner scale, and a self-designed questionnaire preoperatively and 24 months postoperatively. Fixation stability of the implant was evaluated radiographically in two planes by comparing the medial proximal tibial angle (MPTA) and tibial slope 2 days after medial owHTO (baseline measurements) and after implant removal (follow-up measurements). Complications were recorded during the whole study period.
RESULTS: Compared to preoperative conditions, VAS, WOMAC, and Lysholm scores improved significantly (p < 0.05) at the 12- and 24-month follow-up. No significant differences were found between the 12- and 24-month follow-up. After 24 months, the sports frequency increased significantly (p < 0.05). No significant differences between baseline and follow-up measurements for the MPTA and tibial slope were observed. Total complication rate was 4 %, with one patient developing non-union.
CONCLUSION: In the clinical practice, the 2nd generation PEEKPower HTO-Plate(®) is a safe and efficient implant for medial owHTO without bone grafting in patients with an osteotomy gap of ≤12 mm. LEVEL OF EVIDENCE: III.