A Cochrane review included 21 studies with a total of 1065 subjects. All the studies concerned a valgus high tibial osteotomy (HTO) for medial compartment osteoarthritis of the knee.
Four studies evaluated a closing wedge high tibial osteotomy (CW-HTO) with another high tibial osteotomy (aHTO). Based on these studies, the CW-HTO group had 1.8% (95% CI)-7.7% to 4.2%) more pain compared with the aHTO group. Pooled function in the CW-HTO group was 0.5% (95% CI -3.8% to 2.8%) higher compared with the aHTO group. No data on health-related quality of life and mortality were presented. Serious adverse events were reported in only four studies and were not significantly different between groups. The reoperation rate were scored as early hardware removal because of pain and pin track infection due to the external fixator. Risk of reoperation was 2.6 (95% CI 1.5 to 4.5) times higher in the aHTO group compared with the CW-HTO group.
Two studies compared high tibial osteotomy versus unicompartmental knee replacement. Treatment failure and pain and function scores were not different between groups after a mean follow-up of 7.5 years. The osteotomy group reported more adverse events when compared with the unicompartmental knee replacement group, but the difference was not statistically significant. No data on health-related quality of life and mortality were presented. No study compared an osteotomy versus conservative treatment.
Six studies compared different surgical techniques used in a HTO. One study compared HTO alone versus HTO with additional treatment. Four studies compared within the same type of HTO, different peri-operative conditions (two studies) or two different types of post-operative treatment (two studies). Two studies, including the longer follow up, compared HTO with unicompartmental joint replacement. No study compared an osteotomy with conservative treatment. Most studies showed improvement of the patient (less pain and improvement of function scores) after osteotomy surgery, but in the majority of the studies there was no significant difference with other operative treatment (other technique of HTO/ unicompartmental joint replacement).Comment: The quality of evidence is downgraded by imprecise results (few patients and wide confidence intervals) and by study quality (inadequate or unclear allocation concealment, inadequate follow up).