Abstract
Introduction
Total knee replacement has been well-established form of treatment both for osteoarthritis and inflammatory arthritis. Both cemented and uncemented TKR have been used successfully. Since 1977 low contact stress (LCS) mobile bearing knee replacement has been in extensive use. Most of the intermediate and long term results reported are in osteoarthritis1–7. Though there are several studies reporting short term performance of TKR in rheumatoid arthritis8–19 there have been rare reports31 of intermediate to long-term performance of LCS uncemented TKR in rheumatoid arthritis.
Methods
Retrospective, non-randomised and consecutive study. Case notes and radiological assessment done. Kaplan meyer survival analysis used. Radiological assessment between initial and final xrays done using T test statistics. Assessement done by two independent observer.
Results
108 knees in 67 patients are collected. 21 patients with 36 knees have died.
Only 65 knees in 42 patients had both case notes and xrays which are included in this study. Of this 11 knees in 7 patients were dead. All 65 knees in 42 patients are sero-positive rheumatoid arthritis. Pre-operative bone loss was seen only in 4 knees. Bone loss was in the medial side in 3 knees (4,5 and 8mm respectively) and lateral in 1 knee (1 cm). None of these bone loss needed bone grafting or any special procedures. There was no subsidence in any of the 65 knees. Survival of uncemented LCS TKR in inflammatory arthritis patients is 100%. Aseptic failure is 0%. No infective failure. There is no significant change in the implant position. This is the longest follow for uncemented TKR in inflammatory arthritis ever reported in the literature.
Conclusion and Discussion
In conclusion, our study has uniformity, as a single surgeon performed/supervised with senior trainees all the operations and all patients received the same level of post-operative care. Survival of LCS uncemented TKR in inflammatory arthritis patients is 100% up to 15years. This is the longest follow up in this patient population ever reported in the literature. Our study shows excellent survival and comparable to other cemented TKRs in this patient population reported in the literature. This study proves contrary to the general belief that uncemented TKR do poor in inflammatory arthritis due to osteoporotic bone.
