To compare the efficacy of medial open wedge high tibial osteotomy (OWHTO) and medial unicompartmental knee arthroplasty (UKA) in the treatment of medial unicompartmental osteoarthritis of the knee combined with proximal tibial deformity.

The clinical efficacy of patients with knee osteoarthritis admitted to Suining Central Hospital from January 2016 to January 2020 was retrospectively analyzed. The patients were divided into unicompartmental knee arthroplasty group and high tibial osteotomy group according to the type of surgery. Oxford knee score (OKS), Lysholm function score, blood loss, operation time and hospital stay length were collected and analysed. The measurement data in accordance with normal distribution were compared between groups by t test or repeated measures analysis of variance; the enumeration data were expressed as constituent ratio and chi-square test was used.

There were 41 patients, 21 in the UKA group and 20 in the OWHTO group, and all the patients were followed for at least one year. Before operation, in UKA group, blood loss in less(t=13.849, P<0.05)and shorter OWHTO operation time (t=2.263, P <0.05); no statistically significant difference was found in postoperative hospital stay (P >0.05). Lysholm function score and OKS score at three, six months and one year after operation were improved compared with those before operation. At three and six months after surgery, the Lysholm function score and OKS score in the UKA group were better than those in the OWHTO group (t=-4.471, -2.117, 10.076, 2.689, all P<0.05). One year after surgery, there was no significant difference in Lysholm knee function score and OKS score between the two groups (all P>0.05). The tibiofemoral angle in both groups decreased after operation compared with that before operation (t=13.937, 22.331, both P<0.05), and the correction of tibiofemoral angle in OWHTO group was better than that in UKA group (t=6.952, P <0.05). During the follow-up, one patient in the UKA group developed polyethylene liner dislocation one year after surgery, and one patient developed numbness around the surgical incision and anteromedial leg after surgery. No relevant complication was observed in the OWHTO group.

Both UKA and OWHTO are effective in the early postoperative period in patients with medial compartment osteoarthritis of the knee combined with proximal tibial deformity, and the function of UKA is improved more rapidly. OWHTO can correct genu varus better.