There has been great renewed interest in the past few years in unicompartmental arthroplasty for medial arthrosis of the knee due to the advantages over total knee replacement.
A retrospective epidemiological study was performed with 25 consecutive patients (30 knees) from January 2002 to September 2013, who underwent unicompartmental knee arthroplasty with a phase 3 Oxford prosthesis using polyethylene inserts with an ultra-congruent design. With an average follow-up of 6.1 years (1.1-11.5 years). The following demographical variables were analyzed: weight, size, body mass index and perioperative variables like hemoglobin, bleeding and surgical time; we evaluated the pre and post-operative function of patients according to clinical and functional scales. We performed a clinical and radiological evaluation of the implant to check for the presence of arthrosis changes in non-intervened compartments.
We observed optimal survival of the implant. The clinical Knee Score Society improved from 61 in the pre-op to 84 at the end of the follow-up period, with 90% excellent and good results. At the end of the follow-up the average post-surgical flection was 120 degrees and full extension. Only two patients showed satisfactory results due to progression of the arthrosis in the lateral compartment and only one patient required conversion to total replacement in two surgeries due to a periprosthetic infection.
Unicompartmental knee arthroplasty is a less invasive surgery with good clinical and functional results. The success of the procedure is based on the proper selection of patients.