From 1985 to 1990, the porous-coated anatomic (PCA) primary total knee system was employed at our hospital in Japan. Eighty TKAs with PCA primary were performed in 55 patients. Seventy-four joints in 50 patients were followed up for this study. The follow-up period was 6 to 11 years, and the follow-up rate was 91%. In both the RA and OA patients, the pain scores improved remarkably, and the scores for ambulation, contracture, deformity, and ADL increased, but the scores for ROM did not rise. Revision surgery was performed on six joints because of polyethylene wear in four and mechanical loosening in two. Definitive diagnosis of polyethylene wear was made by varus/valgus stress testing under fluoroscopy. Early diagnosis of polyethylene wear is important to prevent further severe damage to the knee joint.

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Although late segmental collapse of the femoral head sometimes follows intracapsular fracture of the femoral neck, the mechanism of this lesion is not well understood. We obtained T1-weighted magnetic resonance imaging (MM) images of the femoral head after fracture of the femoral neck and classified the signals into four patterns to investigate the sequential changes of the femoral head. The T1 -weighted MM images obtained initially after femoral neck fracture showed a normal pattern in 10 of the 15 hip joints studied, a homogeneous pattern in one hip joint, an inhomogeneous pattern in three hip joints, and a band pattern in one hip joint. MM images obtained subsequently still showed the normal signal pattern in eight of the 10 hip joints which had shown the normal pattern in the first MM, while two of the 10 joints subsequently showed a band pattern. The joint with the homogeneous pattern in the first MM subsequently showed a band pattern. Of the three joints with an inhomogeneous pattern in the first MM, two joints showed a subsequent band pattern, and the other a normal pattern. The joints which showed a band pattern continued to show a similar band pattern. Eventually, all hip joints studied showed a normal or band pattern within six months after intracapsular fracture of the femoral neck. The joints which showed a band pattern in the first MM continued to show a similar band pattern in the subsequent MM, without any change. Collapse occurred in one hip joint which showed an extensive band pattern. Plain X-rays showed collapse of one of the joints with a band pattern in the MM image. It was therefore suggested that necrosis may be present histologically in the femoral head after fracture of the femoral neck even when no abnormalities are present in plain X-rays. Based on the above results, it is considered necessary to follow-up patients with femoral neck fracture with MRI for at least six months until the normal or band pattern is observed. Since hip joints with an extensive band pattern are susceptible to collapse, it is neces-sary to monitor such patients carefully.

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There are many reports concerned with the etiology of patellar subluxation and dislocation (recurrent dislocation), but there are few reports of biomechanical and dynamic analysis for this disease, particularly regarding femoro-tibial movement. We studied the results in 17 patients (one male and 16 female) who had recurrent dislocation of the patella and were treated by a modified Roux-Goldthwait procedure consisting of lateral retinacular release, medical transfer of the lateral part of the patellar tendon without advancement, plication of the medial retinaculum, and advancement of the vastus medialis. The biomechanical results were analyzed after one year postoperatively. A three-dimensional dynamic analysis was made on the knee with patellar recurrent dislocation, using CA-4000 knee motion analyzer. This study demonstrated that the modified Roux-Goldthwait procedure can stabilize the patella by getting normal rotation of the femoro-tibial joint with physiological screwhome movement. We confirmed that this procedure normalized the rotation of the femoro-tibial joint in recurrent patellar dislocation.

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The accuracy of Intramedullary (IM) versus extramedullary (EM) tibial alignment systems was compared in 71 total knee arthroplasties (TKAs) on postoperative roentgenographs. In 30 knees of patients with osteoarthrosis, and in 11 knees of patients with rheumatoid arthritis, the IM system was used (OA IM group and RA IM group) . In 30 knees of patients with rheuma toid arthritis, the EM system was used (RA EM group) . The AMK total knee system was used in all cases. Roentgenographic measurements were taken of the tibial component in the coronal and sagital plane, named the“medial angle”and“posterior tilting angle.”The average medial angle was 88.9° (standard deviation [SD] ±2.3°) for the OA IM group; 85.8° (SD±2.0°) for the RA EM group; and 88.4° (SD±2.3°) for the RA IM group. These differences were statistically significant between the OA IM group and the RA EM group (p<0.01) and between the RA IM group and the RA EM group (p<0.001) . The average posterior tilting angle was 5.2° (SD±3.4°) for the OA IM group, 3.3° (SD±2.9°) for the RA EM group, and 7.2° (SD±3.0°) for the RA IM group. These differences were statistically significant between the RA EM group and the RA IM group (p<0.01) . The results demonstrated a statistically significant improvement in proximal tibial-bone-resection accuracy when using the IM system. However, the IM rod is not satis factory when the tibia is bowed. If the preoperative planning radiograph suggests it to be nec essary, the entry point should be varied; usually this is in a slight lateral direction.

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We reviewed 11 rheumatoid arthritis patients who had undergone total hip arthroplasty using the Müller acetabular support ring for acetabular reinforcement. The mean age at time of operation was 58.5 years, and the follow-up period was 32.9 months on average. Clinical results were assessed according to the JOA scoring system. Roentgenographic evaluation was assessed based on migration of the ring, screw breakage, and distribution of reactive lines around the prosthesis. JOA scores improved from 32.6 points preoperatively to 73.9 points at the time of last follow-up. No significant roentgenographic failures, including migration of the ring or screw breakage were observed. Furthermore, reactive lines were not observed around the ring and screw. The present results indicate that the Müller support ring is useful in treatment for rheumatoid arthritis patients with acetabular bone deficiencies.

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Thirty-six operations were performed on 21 patients with systemic lupus erythematosus (SLE) from 1987 to 1996 at Okayama University Hospital. All patients had been treated with corticosteroid administration. The average age of onset of SLE was 29 years (16-56 years), and the average age at time of operations was 40 years (18-61 years) . Fifteen total hip replace ments (THR), 6 Sugioka's transtrochanteric rotational osteotomies, 5 femoral head replace ments (FHR), 2 humeral head replacements (HHR) and 2 total knee replacements (TKR) were performed for osteonecrosis. Two arthrodeses of the CM joint of the thumb were performed for Jaccoud deformity. In the cases of THR and FHR, no migration of implants were seen and the results were very satisfactory. However, the results of Sugioka's osteotomies were poor. Collapse progressed in three femoral heads and two were salvaged by THR. In one case, dislo cation of the femoral head occurred at SLE crisis. As fatal postoperative complications, pulmonary embolism in one revision THR patient and intestinal perforation in one HHR patient were seen. One patient with intestinal perforation followed by panperitonitis died of sepsis. In one TKR patient, late infection occurred and infection did not subside without removal of the prosthesis. Surgical treatment for SLE patients should not be performed without taking these results and complications into consideration.

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We investigated the clinical results of Sauvé-Kapandji procedure for treatment of the rheumatoid wrist joint. Sixteen wrists with rheumatoid arthritis had undergone the Sauvé-Kapandji procedure. The clinical symptoms, grip strength, range of motion of the wrist, and X-ray findings were examined. X-ray findings were evaluated for radial rotation angle (RRA), radial carpal distance ratio (RCDR) and carpal height ratio (CHR) . Pain was relieved in 15 patients. Grip strength was 64% of the opposite side preoperatively and 79% postoperatively. The average range of spination-pronation of the forearm increased from 118°preoperatively to 148°postoperatively, although the range of wrist flexion-extension decreased slightly. Three patients had a slight increase in RRA and RCDR. No collapse of carpal bone was seen in any of the patients.
The Sauvé-Kapandji procedure obtained pain relief and increased forearm pronation and supination. The carpal translation and radial rotation of the carpal bone were increased in some cases. In conclusion, the Sauvé-Kapandji procedure obtained satisfactory results in the rheumatoid wrist joint, even in cases of radiological progression of rotation and ulnar shift of carpal bone.

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A case of stress fracture of the medial tibial plateau after lateral unicompartmental arthroplasty was reported. The patient was a 67-year-old woman who suffered from lateral compart mental osteoarthritis of the right knee. Radiographs of the right knee showed osteoarthritic changes of grade 5 (Yokohama City University grading in weight-bearing radiogram) . A uni compartmental arthroplasty was performed to treat severe valgus deformity of the knee. The patient had sudden knee pain at 3 months after surgery. Radiographs were taken immediately, which showed a thin horizontal band of increased bone density 8 mm below the articular mar gin of the medial tibial plateau. At the same time, a bone scintigram was taken which showed increased uptake in the same site as the osteosclerotic band in the radiograph. From these findings, a stress fracture was suspected. The correction of the valgus limb alignment by which the weight-bearing axis might pass through the medial compartment of the knee, and postoper ative increase of the activities of daily life were thought to be the cause of this fracture. The treatment included the restriction of the patient's activities, and a knee cage was applied. At 6 months after surgery, there were no recurrence of the symptoms or refractures.

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