PURPOSE: The purpose of the present study was to systematically review the clinical and functional outcomes following medial unicompartmental knee arthroplasty (UKA) in patients under the age of 60 years old.
METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, studies between 2012 and April 2022, on patients 18-60 years old who have had a unicompartmental knee replacement evaluating patient-reported outcomes measures (PROMs), were included. The Knee Society Scores (KSS) clinical score was considered the primary outcome. Pre- and post-operative range of motion (ROM), PROMs, complications and survival were recorded. Paired sample t testing was performed to compare the pre-operative with post-operative KSS.
RESULTS: Seventeen articles comprising 2083 unicompartmental arthroplasties were included. The follow-up range was between 1 and 15 years. In eligible studies, all reported outcomes were improved following UKA. The mean KSS clinical was significantly improved from 45.5 (SD: 9.6) pre-operatively to 89.4 (SD: 4.4) post-operatively (p = 0.0001). Mean implant survival ranged 86-96.5% at 10 years follow-up. There was no significant difference between mobile and fixed bearing in terms of ROM and KSS clinical. In total, 92 revisions and 7 re-operations with implant retention were reported.
CONCLUSION: Unicompartmental knee arthroplasty for medial osteoarthritis is a safe, reliable and effective treatment option for patients of 60 years or younger. It provides pain relief, satisfactory activity level, excellent clinical outcomes, and up to 96.5% implant survival at 10-year follow-up.
LEVEL OF EVIDENCE: IV.