Abstract
Introduction: The introduction of the Oxford Phase 3 unicompartmental knee arthroplasty (UKA) by a minimally invasive technique has significantly changed the treatment of medial osteoarthritis of the knee joint. The purpose of this study was to analyse our early results and to evaluate the clinical importance of the learning curve of the procedure.
Material and methods: Patients who were operated between January 1999 and September 2003, were divided in two groups. Group A consists of 34 patients (35 prostheses) who were operated between January 1999 and December 2001 with a minimal follow-up (FU) time of 24 months. The second group (B) consists of 41 patients (44 prostheses) who had surgery between January 2002 and September 2003 with a FU of minimal 12 months. WOMAC score, Oxford score, Knee Society knee/function score, VAS for pain and satisfaction, radiographical alignment, operation time and complications were documented and compared between the two groups. A slight modification of the operation technique was applied in the second group.
Results: The Knee Society function score differed significantly in favour for group B (81.5 A vs 88.1 B; p< 0.05). The Knee Society knee score was: 86.7 (A) vs 89.7 (B). The postoperative VAS for pain and satisfaction were slightly in favour for the second group. The Oxford and WOMAC score did not differ significantly. The ROM was 125.1 (A) vs 126.7 (B) degrees. The operation time was 84 (A) vs 64 (B) minutes. The radiographical tibio-femoral alignment was 6.1 (A) vs 6.4 (B) valgus. Optimal radiographical positioning of the three components was 51% (18/35;A) vs 80 % (35/44;B). Two complications were encountered only in the first group: dislocation of the meniscal bearing component, and lesion of the lateral meniscus. There were three patients with moderate pain complaints in group A and two in B.
Conclusions: This study shows that when an appropriate surgical technique is mastered from the very beginning, good to excellent clinical results can be achieved even in the learning curve period. The positioning of the prosthesis, as confirmed by radiographical study, after using our own modification of the surgical technique was improved.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
