Results of Unicompartmental Knee Arthroplasty at a Minimum of Ten Years of Follow-up

• Published in: Journal of bone and joint surgery. American volume Vol. 87; no. 5; pp. 999 - 1006
• Main Authors: Berger, Richard A, Meneghini, R Michael, Jacobs, Joshua J, Sheinkop, Mitchell B, Della Valle, Craig J, Rosenberg, Aaron G, Galante, Jorge O
• Format: Journal Article
• Language: English
• Published: Copyright by The Journal of Bone and Joint Surgery, Incorporated 01-05-2005
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/JBJS.C.00568

BackgroundThere is a renewed interest in unicompartmental knee arthroplasty. The present report describes the minimum ten-year results associated with a unicompartmental knee arthroplasty design that is in current use.MethodsSixty-two consecutive unicompartmental knee arthroplasties that were performed with cemented modular Miller-Galante implants in fifty-one patients were studied prospectively both clinically and radiographically. All patients had isolated unicompartmental disease without patellofemoral symptoms. No patient was lost to follow-up. Thirteen patients (thirteen knees) died after less than ten years of follow-up, leaving thirty-eight patients (forty-nine knees) with a minimum of ten years of follow-up. The average duration of follow-up was twelve years.ResultsThe mean Hospital for Special Surgery knee score improved from 55 points preoperatively to 92 points at the time of the final follow-up. Thirty-nine knees (80%) had an excellent result, six (12%) had a good result, and four (8%) had a fair result. At the time of the final follow-up, thirty-nine knees (80%) had flexion to at least 120°. Two patients (two knees) with well-fixed components underwent revision to total knee arthroplasty, at seven and eleven years, because of progression of patellofemoral arthritis. At the time of the final follow-up, no component was loose radiographically and there was no evidence of periprosthetic osteolysis. Radiographic evidence of progressive loss of joint space was observed in the opposite compartment of nine knees (18%) and in the patellofemoral space of seven knees (14%). Kaplan-Meier analysis revealed a survival rate of 98.0% ± 2.0% at ten years and of 95.7% ± 4.3% at thirteen years, with revision or radiographic loosening as the end point. The survival rate was 100% at thirteen years with aseptic loosening as the end point.ConclusionsAfter a minimum duration of follow-up of ten years, this cemented modular unicompartmental knee design was associated with excellent clinical and radiographic results. Although the ten-year survival rate was excellent, radiographic signs of progression of osteoarthritis in the other compartments continued at a slow rate. With appropriate indications and technique, this unicompartmental knee design can yield excellent results into the beginning of the second decade of use.Level of EvidenceTherapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.