Analysis of revision procedures for failed unicondylar knee replacement

Introduction Unicondylar knee arthroplasty (UKA) is argued to be a conservative procedure which permits a later total knee arthroplasty (TKA) should it be required. Aim The aims of the study were to assess the modes of early failure of UKA and see whether the conversion to TKA improved the functional scores, range of motion, pain and patient satisfaction. Method Fourteen revision procedures performed after failed unicompartmental knee arthroplasty (UKA) were evaluated. Patient demographics, modes of failure and technical issues relating to revision were noted. Post-operative functional outcome was assessed using WOMAC osteoarthritis index and SF-36 scores. Results Thirteen percent of primary UKA performed were revised to TKA. Eighty-six percent of the revisions were required within the first 12 months. Revision procedure was complex in nearly half of the cases. There was no significant improvement in post-operative functional scores. Conclusion Results of conversion of UKA to TKA are less satisfactory than primary TKA.