To compare the efficacy of cemented unicompartmental knee arthroplasty (UKA) with cementless UKA in treatment of medial compartmental gonarthrosis.

The data related to randomized controlled trial(RCT) and clinical controlled trial (CCT) which compare the treatment of cemented UKA with cementless UKA for medial gonarthrosis from Jan 2000 to Oct 2019 were searched in the Pubmed、The Excerpta Medica Database (Embase)、Cochrane Library、Web of Science、China National Knowledge Infrastructure (CNKI) and Wanfang database. The literatures that were duplicated, low quality, irrelevant to the observation index or not accessed to the full-text were excluded. Two authors independently extracted data and assessed the methodological quality with Cochrane risk tool and Newcastle Ottawa Scale (NOS). Meta analysis was performed using Revman 5.3 to compare the differences in the two fixation UKA about the radiolucency, the 5-year survival rate of the prosthesis, the Oxford knee score (OKS), complications, and operation time.

A total of nine articles were included, with a total of 18 702 cases, including 8 735 in the cementless group and 9 967 in the cement group. The results of meta analysis showed that the incidence of complete radiolucency around the prosthesis in the cementless group was lower than that of the cemented group [odds rate (OR) = 0.08, 95% confidence interval (CI) (0.01, 0.42), P=0.003], the OKS is higher [mean difference (MD)=2.08, 95% CI (0.51, 3.65), P=0.009], The 5-year prosthesis survival rate was higher [OR=1.39, 95% CI (1.20, 1.60), P<0.0001], and the operation time was shorter [MD=-9.23, 95% CI (-13.72, -4.74), P< 0.0001]. There was no statistically significant difference between the two groups in the incidence of complications [OR=0.43, 95% CI (0.17, 1.09), P=0.07].

Compared with cemented UKA, cementless UKA has less complete radiolucency lines, higher OKS score, higher 5-year survival rate, shorter operation time and comparable complication rate, which is worthy of being promoted.