To compare the short-term effect between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) in the treatment of single-compartment osteoarthritis of the medial knee in elderly patients, and to provide a reference for surgical options.

A retrospective analysis was conducted on 40 elderly patients (40 knees) with medial single-compartment osteoarthritis of the knee using the third-generation Oxford unicompartmental system in the Department of Osteoarthritis, Chifeng Municipal Hospital from December 2014 to December 2018, and set them as the UKA group. A total of 40 elderly patients with medial compartment osteoarthritis of the knee (40 knees) who received TKA treatment at the same time were selected as the TKA group. Patients in the UKA group underwent medial unicompartmental knee arthroplasty. During the operation, cartilage in other compartments, lateral meniscus, anterior and posterior cruciate ligaments were preserved, and partial knee prosthesis (the third-generation Oxford single condyle prosthesis) were installed. Patients in the TKA group underwent TKA, in which the cartilage, medial and lateral meniscus and anterior and posterior cruciate ligaments of the medial and lateral compartments were removed, and a total knee prosthesis (Nexgen prosthesis) was installed. The two groups of patients underwent outpatient follow-up at 3, 6, and 12 months after surgery. The hospital for special surgery (HSS) score, visual analogue score(VAS), knee joint range of motion, hemoglobin were observed and recorded before and at the last follow-up. The postoperative complications, blood transfusion rate and length of hospital stay were compared between the two groups. Data wasprocessed with t test, chi-square test.

All patients in the two groups were followed-up, and all patients were followed-up to 12 months after surgery, and the results of the last follow-up were taken as the criterion. There were no statistically significant differences in HSS score, VAS score, knee joint range of motion, and hemoglobin between the two groups of patients before operation (P>0.05). The HSS score, VAS score, knee range of motion, and hemoglobin of the two groups at the last follow-up were significantly improved compared with those before the operation, and the differences were statistically significant (P<0.05). At the last follow-up, the HSS score and VAS score in the UKA group were (88.7±4.5), (1.5±0.3) points, respectively, compared with the TKA group [(87.1±5.1), (1.8±0.4) points], the differences were not statistically significant (P>0.05). The knee range of motion of the UKA group was (121.3±8.4)°, which was better than that of the TKA group [(110.2±9.6)°], the difference was statistically significant (P<0.05). The hemoglobin of the TKA group was (91.1±16.0) g/L, compared with the UKA group [(106.5±15.8) g/L], the difference was statistically significant (P<0.05). Complications rate in the UKA group was 3 cases (7.5%), which was significantly lower than that in the TKA group [10 cases (25.0%)], and the difference was statistically significant (P< 0.05). The blood transfusion rate in the TKA group was 35 cases (87.5%), which was significantly higher than the UKA group [2 cases (5.0%)], and the difference was statistically significant (P<0.05). The patient hospitalization time in UKA group was (7.5±1.2) d, compared with TKA group [(10.3±1.7) d], the difference was statistically significant (P<0.05).

For the elderly patients with single-compartment osteoarthritis of the medial knee, the short-term clinical effect of UKA treatment is more obvious than that of TKA. It also has shorter hospital stay, less trauma, lower blood transfusion rate, fewer postoperative complications rates, faster recovery, etc. The advantages are worthy of clinical application.