Abstract
Treatment of the femoral neck fracture seems to be still confused when encountered in rheumatoid arthritis and no general agreement on the treatment has yet been reached. We reported six cases treated by open reduction and internal fixation in 1980. However, most of them have had various complications during these four years excluding one case with Garden-2 grade displacement and fixed with multiple pinning. Therefore, we have concluded that osteosynthesis can only be indicated on relatively young patients who have slight to mild osteoporosis, up to 3 grade in Garden's classification, and well controlled in RA activity.
We have treated 11 rheumatoid cases with 13 femoral neck fractures up to present, and the results are reported in this paper. All cases were women with definite or classical RA. Average age at operation was 64.4 years (from 39 to 78 years) . RA stage of these patiens was 3 or 4 and class was 2 to 4. Clinical results were assessed by the hip score of the Japanese Orthopedic Association. Grade of osteoporosis on the X-ray film of the hip joint was evaluated by the Singh Index. The average follow-up period was 2.6 years.
Osteosynthesis was performed on two hips according to the indications mentioned above. No complications were experienced in these cases and the final clinical score at follow-up (average 2. 7 years) was 92 and 83 points respectively.
Femoral head replacement was selected in 8 hips which showed marked displacement or over moderate osteoporosis. Austin-Moore type prosthesis was used in 4 hips and bi-articular hip prothesis (Bateman type) in 4 hips. One patient died by heart failure 8 months after the operation. Average clinical score of the other 7 patients was 75 points and there is no significant difference between the two types of prosthesis at present. Though no difinite determination of which prosthesis is better could be made because of the shortness of the follow-up study, bi-articular hip prosthesis can bechosen due to biomechanical superiority.
Three patients who had high activity or severe osteoporosis received the Chernley-Müller type of total hip replacement (THR) . Their average clinical score was 69 points and lower than in hemiarthroplasty. One of them showed stem loosening and complained of moderate pain on walking. No complaints about the hip joint have been found in the other two cases but their RA activity with disability has advanced recently. Careful evaluation is necessary for indication of THR.
With respect to pathomechanism, no inducing accident could be detected in the four cases. All were relatively old women and had a long period of disease. Two of them had history of long steroid administration and two had an ipsilateral TKR operation from 6 to 12 months before. Singh Index was 2 or 3 in these cases. The mechanism in these cases seemed to be a stress fracture. The patients who have the inducing factors such as previous TKR or steroid administration should be watched carefully.
