A systematic review of outcomes of high tibial osteotomy for the valgus knee

Purpose: Osteoarthritis is a prolific condition in an increasingly ageing and obese population. Research into treatments of this condition and their efficacy are vital. Outcomes of high tibial osteotomy (HTO) for the varus knee is widely reported. There is less evidence for HTO in the valgus knee. This systematic review aimed to compile all literature reporting the outcomes of HTO to correct the valgus knee, focusing on post-operative clinical outcomes. Methods: Ovid MEDLINE, Embase and Web of Science were searched using key terms: Osteoarthritis [All Fields] AND High tibial osteotomy [All Fields] AND Lateral OR Valgus [All Fields]. Papers were screened for eligibility based on an inclusion and exclusion criteria. Full text screening was completed by two reviewers and data was extracted from the agreed included papers by one reviewer. Quality assessments of the papers were also conducted. PROSPERO ID: CRD42021239045. Results: Across 17 papers reporting 517 knees, the average pre-operative femorotibial and hip-knee-ankle angles were corrected from 13.6 +/- 7.0 degrees and 4.9 +/- 1.9 degrees valgus to 2.8 +/- 2.9 degrees D and 1.2 +/- 1.7 degrees varus. Studies show that the procedure is successful at offloading the lateral knee compartment and some evidence it can delay the need for a total knee replacement. However, its impact on overall quality of life remains poorly understood. Conclusions: High tibial osteotomy may be a viable treatment option for valgus knee deformities caused by lateral compartment osteoarthritis. Nevertheless, research into the procedure remains limited. Importantly, our understanding of the relationship between the achieved alignment and outcome remains largely unknown.