[Effectiveness of open wedge high tibial osteotomy on medial unicompartmental knee osteoarthritis]

To evaluate the effectiveness of open wedge high tibial osteotomy (OWHTO) in treatment of medial unicompartmental knee osteoarthritis (MUKOA).

A clinical data of 61 cases with MUKOA who were treated with OWHTO between January 2015 and January 2017 were retrospectively analyzed. There are 14 males and 47 females with an average age of 52.8 years (mean, 44-60 years). The body mass index ranged from 19.1 to 34.7 kg/m ² (mean, 25.3 kg/m ²). Twenty-seven cases were left side and 34 cases were right side. The disease duration was 1-9 years (mean, 5.3 years). The MUKOA was rated as stage Ⅱ in 33 cases and stage Ⅲ in 28 cases. Preoperative Hospital for Special Surgery (HSS) score was 56.0±3.7. Walking visual analogue scale (VAS) score was 4.6±1.0.

The operation time was 49-85 minutes (mean, 66.5 minutes). The length of incision was 10-13 cm (mean, 11.0 cm). The total overt blood loss was 80-210 mL (mean, 139.1 mL). The postoperative bed-rest time was 1-10 days (mean, 4.7 days). All patients were followed up 12-24 months (mean, 17.3 months). The bearing area of tibial platform at 3 months after operation was 60.3%-66.8%, with an average of 63.4%. At 3 and 6 months after operation, the HSS score was 79.1±4.2 and 85.3±3.1 respectively, and the VAS score was 1.7±0.7 and 0.6±0.5 respectively, all showing significant differences ( P<0.05).

OWHTO is an ideal choice for treating MUKOA with less postoperative complications. The force line could be corrected by OWHTO. However, the preoperative preparations are very important, especially that the open angle should be measured accurately.