According to the reports of a meta-analysis of retrospective observational studies published in the Archives of Orthopaedic and Trauma Surgery cemented unicompartmental knee arthroplasty (UKA) shows significant efficacy in managing the spontaneous osteonecrosis of the knee (SONK) and medial compartment osteoarthritis (MOA).

Cochrane Library, MEDLINE, and Embase were searched using keywords associated with knee arthroplasty and SONK. Predetermined inclusion criteria comprised (a) medial UKA as the primary method, (b) inscribing implant clinical or survival outcomes of osteoarthritis and osteonecrosis, and (c) follow-up period > 1 year were followed to select the studies. The risk of bias assessment tool was used to perform the quality assessment and random-effects model to determine the pooled relative risk (RR) and standardized mean difference.

As compared to the MOA group, SONK showed a higher incidence of UKA revision. But, both groups showed no difference in the risk of revision, if it was due to the aseptic loosening. Also, after stratified by study quality, both groups involved similar risk of overall revision as per the high-quality studies. Further, no significant difference was noticed between the groups regarding the failure after cemented mobile and fixed bearing UKA. Only one study reported the outcomes of uncemented UKA, which revealed the higher failure of SONK than MOA. Both MOA and SONK showed similar clinical results after the UKA. A further need for prospective studies is essential to compare the UKA outcomes in SONK and MOA.