Abstract
Introduction: The use of the Oxford Phase 3 unicompartmental knee arthroplasty (UKA) in the treatment of anteromedial osteoarthritis of the knee in elderly patients is controversial. The aim of this study was to analyse the performance of patients 75 years of age or older after surgery with the Oxford Phase 3 prosthesis by a minimally invasive technique.
Material and methods: Between January 1999 and September 2004, 128 Oxford Phase 3 prostheses were implanted by a single surgeon. Patients with a minimal follow up (FU) of one year were divided in two groups depending on age. (Group A less than 75 years, group B 75 years or more.) Loss to FU was documented. The pre and postoperative clinical outcome of the patient with the new implant was objectively evaluated by a visual analog pain and satisfaction score, the WOMAC Score, Oxford score, the Knee Society knee score and Knee Society function score. The range of motion (ROM) was documented.
Results: Fourty-five patients were under the age of 75 (group A). Thirty patients were 75 or older (group B). In the second group 4 patients were lost to FU: two deceased and two due to severe illness. Mean age (range) in the first and second group was 67 (47–74 yrs) and 79 (76–87) years respectively. Both groups had a mean FU time of 29 months. In the preoperative scores there was a significant difference in the WOMAC function score (49.7 A vs 42.4 B), Knee Society knee score (51.2 A vs 45.5 B) and the Knee Society function score (51.7 A vs 41.4 B).The pre-operative ROM was 120.1 (A) vs 122.7 (B) degrees. Comparing the postoperative scores a significant difference was found in the Knee Society knee score (89.1 A vs 78.0 B) and in the WOMAC function score (77.8 A vs 74.0 B). The Oxford score and the postoperative VAS for pain and satisfaction were slightly in favour for the younger group, but did not differ significantly. The postoperative ROM was 126 degrees in both groups.
Conclusions: This study shows that in both groups the scores are good to excellent but slightly in favour for the younger group of patients operated for anteromedial osteoarthritis using a minimally invasive approach. Patients’ satisfaction is high in both groups. The slight difference in scores may be due to the presence of comorbidity in the older patient. Although the follow up in this study is the shortterm we advocate the use of the Oxford Phase 3 prosthesis in the elderly patient. The minimally invasive technique will lead to better range of movement, a quicker recovery of the older patient with less risk of complications and will be in our opinion more cost-effective than total knee replacement.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
