Short-term Clinical Effect Of Unicompartmental Knee Arthroplasty For Medial Knee Osteoarthritis Complicated With Subchondral Bone Cyst

Objective:We retrospectively analyzed the postoperative outcomes and therapeutic effects of unicompartmental knee arthroplasty for medial unicompartmental knee osteoarthritis with Subchondral bone cysts(SBCs),as well as the location and distribution of Subchondral bone cysts in patients with advanced knee osteoarthritis.Methods:From December 2019 to February 2021,184 knee joints of patients admitted to our hospital for treatment of knee osteoarthritis were included,and the occurrence sites of knee osteoarthritis combined with subchondral bone cyst were recorded.Among them,patients with medial knee osteoarthritis were selected and treated with Oxford third-generation movable gasket single condyle prosthesis(Biomet Company,UK).Based on inclusion and exclusion standard,30 knees in MOA group and 12 knees in MOA group combined with SBCs were divided into MOA group.Knee pain,joint function and complications were evaluated.Results:Subchondral bone cysts were found in 87 cases(87/184,47.3%)of the 184 knee joints,including 19 cases(19/87,21.8%)with multiple cyst areas,including 106 cyst areas.Cyst area distribution of MF(17/106,16.04%),MT(31/106,29.25%),LF(8/106,7.55%),LT(12/106,11.32%),FIF(13/106,12.26%),TIC(25/106,23.58%).In 19 cases with multiple cyst areas,MF+MT(5/19,26.32%),MT+FIF(6/19,31.58%),MT+TIC(8/19,42.10%)were found.VAS score of MOA combined with SBCs group was significantly higher than that of MOA group(P<0.05),while ROM,HSS score and WOMAC score had no statistical difference(P>0.05).One month after surgery,VAS score,ROM,HSS score and WOMAC score were significantly different between the two groups(P<0.05).VAS score,HSS score and WOMAC score were statistically significant 3 months after surgery(P<0.05),and there were no statistical differences between the two groups after surgery(P>0.05).No complications such as infection,spacer dislocation,periprosthetic fracture,aseptic loosening and joint stiffness occurred in the two groups.Conclusion:Unicompartmental knee arthroplasty can improve the function of knee joint,reduce the degree of pain,and achieve satisfactory postoperative rehabilitation results.We retrospectively analyzed the clinical outcomes of unicompartmental knee arthroplasty in patients with medial single-compartment knee osteoarthritis with subchondral bone cyst.Short-term follow-up showed that these patients also achieved good clinical outcomes.Advanced knee osteoarthritis with subchondral bone cyst usually occurs on the tibial side,especially the medial tibial plateau and the tibial intercondylar crest.