Change in adduction moment following medial open wedge high tibial osteotomy: A meta-analysis

Background: This meta-analysis was designed to quantify adduction moment loss, to evaluate the relationship between changes in mechanical axis alignment and adduction moment, and to assess whether sagittal plane moment is altered after medial open wedge high tibial osteotomy (HTO). Methods: Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, all studies reporting preoperative and postoperative peak knee adduction moment or change in peak knee adduction moment from before to after surgery in patients who underwent medial open wedge HTO were included. Results: Nine studies were included in the meta-analysis. The pooled mean difference in adduction moment from before to after medial open wedge HTO was 1.44% Nm/body weight (BW)xheight (HT) (95% confidence interval [CI]: 1.33 to 1.55% Nm/BWxHT; P < 0.001; I ² = 4%). However, flexion (0.18% Nm/BWxHT, 95% CI:-0.50 to 0.86% Nm/BWxHT; P = 0.61; I ² = 79%) and extension (0.15% Nm/BWxHT, 95% CI,-0.37 to 0.68% Nm/BWxHT; P = 0.56; I ² = 46%) moments did not differ significantly from before to after surgery. Alignment correction amount and postoperative final valgus alignment were not significantly associated with difference in adduction moment from before to after surgery. Conclusion: Knee adduction moment after medial open wedge HTO decreased to 60% of the preoperative level. However, this adduction moment decrement was not affected by the magnitude of alignment correction. In addition, there was no change in sagittal plane knee moment, including flexion and extension moments, from before to after medial open wedge HTO. Level of Evidence: Meta-analysis (Level II).