Early results of medial opening wedge high tibial osteotomy using an intraosseous implant with accelerated rehabilitation.

Abstract

Accelerated rehabilitation protocols for medial opening wedge high tibial osteotomy (MOW HTO) using intraosseous implants have not previously been described. The present study provides early clinical and radiological outcomes of MOW HTO using a polyetheretherketone (PEEK) intraosseous system, in combination with an early weight-bearing protocol. Twenty consecutive knees (17 patients) underwent navigated MOW HTO using a PEEK implant with accelerated rehabilitation. Time to union and maintenance of correction were assessed radiographically for 12months post-operative. Patient outcomes were monitored for a mean follow-up of 38months (range 23-42) using standardised instruments (WOMAC, IKDC and Lysholm scores). All knees were corrected to valgus. The mean time to unassisted weight-bearing was 55days (SD 24, range 21-106). Bone union occurred in 95% of knees by 6months, with correction maintained for 15 knees at 12months post-operative. Knees for which correction was lost within 1year of surgery had significantly greater preoperative varus alignment. Implant survivorship was 95% and 80% at 12 and 38months post-operative, respectively. Significant improvements in patient-reported satisfaction, knee function and return to daily activities from preoperative to 38months post-operative were reported (WOMAC 36 v 0; IKDC 35.6 v 96; Lysholm 44.5 v 100). Accelerated rehabilitation following MOW HTO with an intraosseous PEEK implant did not delay bone union, with significantly improved functional outcomes within 3months post-operative. Early findings suggest that this approach may be suitable for a defined patient subset, with consideration for the extent of preoperative genu varum.