Double-level knee valgization osteotomy has high survivorship and a low complication rate in a single-center series of 58 cases with a mean clinical follow-up of 10 years.

Abstract

Background: Double-level knee osteotomy (DLO) is becoming more popular in bifocal (femur and tibia deformities) as it addresses the deformity where it belongs and results in a more physiologic joint line obliquity. This study reports on the early to midterm outcomes, both clinical and radiological, of valgization DLO for varus knees and the first study to report the 10-year survivorship of this procedure.

Methods: A retrospective review of a prospectively maintained single-center database of 1170 knee osteotomies was undertaken. Patients with bifocal (femur and tibia) varus malalignment and isolated medial compartment osteoarthritis who had DLO corrections [high tibial osteotomy (HTO) and distal femoral osteotomy (DFO)] were included. Multiple patient-reported outcome measures (PROMs) were recorded preoperatively and serially postoperatively. This included the Knee Injury and Osteoarthritis Outcome Score, the Oxford Knee Score, the Oxford Knee Score-Activity and Participation Questionnaire, the Western Ontario and McMaster University Score, the visual analog scale for health and pain, and the EQ-5D. EQ-5D stands for EuroQol 5-dimension. It is a standardized instrument for measuring health-related quality of life (HRQoL). All lower limb alignment indices were recorded pre-and postoperatively. The rates of osteotomy revision, conversion to arthroplasty, complications, and both 8- and 10-year survivorship were recorded.

Results: A total of 58 valgization DLO cases were followed up to a mean of 10.8 ± 3 years. This comprised 74.1% males and 25.9% females, with a mean age of 47.9 ± 9.8 years and a mean body mass index (BMI) of 31.5 ± 6.3 kg/m². The mean planned correction angles for HTO and DFO were 7.7° ± 2.7° and 7.7° ± 3°, respectively. Postoperatively, the mean mechanical tibiofemoral angle improved from -12.7° ± 3.9° (varus) to -0.4° ± 3.4° (i.e., centered around mechanical neutral), the mean medial proximal tibial angle improved from preoperative 84.3 ± 3.2° to postoperative 90° ± 2.5°, the mean mechanical lateral distal femoral angle improved from preoperative 91.6° ± 3.4° to postoperative 86.7° ± 2.5°, and the mean Mikulicz point improved from -5 ± 13.4% to 47.7 ± 14.7% (all p-values < 0.001). All PROMs significantly improved at 24 months follow-up (all p values < 0.001). The rate of osteotomy revision was 3.4%. The overall rate of total knee arthroplasty conversion was 5.2% at an average of 5.9 ± 3.1 years postoperatively. The complication rate was 8.6%. The 8- and 10-year survivorship was 97.1%, and 94.4%, respectively.

Conclusions: In this single-center series evaluating patients with varus knees and bifocal deformities, valgization double-level knee osteotomy (DLO) demonstrated favorable clinical outcomes, accompanied by a low complication rate of 8.6% and a 10-year survivorship of 94.4%. Radiographic findings from available imaging data were positive, although long-term imaging was not consistently obtained. Level of evidence IV retrospective cohort study.