To investigate the early and mid term results of unicompartmental knee arthroplasty(UKA) versus totle knee arthroplasty(TKA) for the treatment of isolated compartmental osteoarthritis of knee.

From March 2014 to March 2016, the patients with medial compartment osteoarthritis treated in Hospital Affiliated to Nantong University were followed up. The inclusion criteria were as follows: age over 60 years old, the varus of knee could be corrected with stress correction; the exclusion criteria were as follows: severe osteoporosis and multiple compartment lesions. There were 23 cases of unicompartmental knee arthroplasty (UKA) and 27 cases of total knee replacement (TKA). The data of two groups were collected, including the hospital for special surgery (HSS) knee score, intraoperative blood loss, hemoglobin reduction, pain score, and the number of days needed for flexion of knee joint to 90 °. The HSS scores and pain scores of two groups were analyzed by repeated measurement of variance analysis. The paired sample t test was used to compare the HSS scores and pain scores of the same group before and after the operation.

The UKA group(22 patients) were followed up for four months to 28 months, (17±4) months on average. All 27 cases in TKA group were followed up completely. The average time was (15±5) months (three to 32 months). UKA group and TKA achieved satisfactory curative effects, two groups did not present prosthesis loosening, renovation or other severe complications. HSS score of UKA group was (64±3) preoperatively, and (85±6) at the last follow-up; the difference was statistically significant(t=-20.066, P <0.05). HSS score of TKA group was (62±3) preoperatively, and (83±5) at the last follow-up; the difference was statistically significant(t=-22.376, P <0.05). Preoperative visual analogue score(VAS) of UKA group was (6.5±0.4), and (1.3±0.6) at the last follow-up; the difference was statistically significant(t=41.764, P<0.05). The preoperatively VAS score of TKA group was (6.6±0.5), and (1.5±0.5) at the last follow-up; the difference was statistically significant(t=46.664, P<0.05). The differences between UKA group and TKA group in the intraoperative blood loss(t=-21.332, P<0.05), the level of hemoglobin decline on day 3 after the surgery(t=-15.470, P<0.05), the postoperative days needed for knee flexion to 90 °(t=-7.341, P <0.05), all presented statistically significant. The differences in the last follow-up HSS score and VAS score between the two groups were not statistically significant ( all P>0.05).

UKA for the treatment of isolated compartmental osteoarthritis of knee can obtain similar early and mid term results to TKA, with less trauma, faster recovery advantages.