Cementless total hip arthroplasty is a useful reconstructive method for patients with hip diseases. However, the appearance of osteopenia of the proximal femur around the implant is a major problem, and several studies have documented objectively the phenomenon of stress shielding in the implanted bone. The purpose of this study was to measure the chronological change of bone mineral density of the femur with a cementless femoral prosthesis using microdensitometry.
Over a one-year period, 29 hips were assessed at regular intervals. The original diagnoses were osteoarthritis in 25 hips, avascular necrosis of the femoral head in 2 hips, and rapidly destructive coxarthropathy in 2 hips. The bone mineral density, the width of bone (D), width of marrow (d), and cortical index (CI: D-d/D) were calculated for the three conditions.
At the proximal part of the femur, d showed an increase at one year but there was no significant progress from that time. CI showed a decrease at one year and a gradual increase after that. At the distal end of the prosthesis, there was no change in bone mineral density 2 years after surgery, but 3 years later, d showed a decrease and CI showed a slight increase.
This study suggests that microdensitometry is an applicable method for evaluating the quantitative bone change of the femur around a prosthesis.

抄録全体を表示

Bone mineral density (BMD) in the femoral condyle after total knee arthroplasty (TKA) was measured with the passage of time using DEXA. We evaluated it with X-rays and clinical findings. The subjects, whose average age was 71.6, were 8 patients (9 joints) with osteoarthritis and 3 patients (4 joints) with rheumatoid arthritis. The follow-up periods were from 12 months to 25 months, with the BMD of total skeleton (T), anterior (A) and posterior (P) femoral condyle measured at 1, 2, 3, 6 and 12 months. As the BMD in total skeleton changes in accordance with the bone metabolism of patients and their ages, the BMD was calculated from the BMD in total skeleton divided by that in ROI of A and P.
The A/T BMD decreased drastically, from 46.1% at one month to 29.0% at 3 months. There was a tendency of gradual decrease after that. However, though the P/T BMD decreased from 73.2% at one month to 50.8% at 3 months after TKA, it increased at 6 months, and did not show much change after that.
As for ROM, an A/T BMD of 43.0% was seen in knees with less than 90 degrees of flexion and of 23.5% in knees of over 110 degrees. Thus the A/T BMD showed a tendency to decrease in patients with a better range of knee motion. There also seemed to be a relationship between stress shielding and ROM.

抄録全体を表示

Heterotopic ossification (HO) was investigated in 126 primary total hip arthroplasties (THAs), and several risk factors which had already been reported to be associated with HO were evaluated.
HO was observed in 41 cases (32.5%) . Some of the risk factors, being male, and having osteoarthritis, hyperostosis, or postoperative dislocation following THA were confirmed in this study. There was, however, no statistical significance between the HO group and the non-HO group with respect to age at THA, serum alkaline phosphatase, bleeding volume or operating time.

抄録全体を表示

In recent years cementless hip joint protheses have been gaining increasing popularity for various reasons, especially in cases of revision, in young persons with hip joint problems. The main problem with this prosthesis lies in the prevention of loosening and the inhibition of femoral bone stress shielding. A radiological study was subsequently undertaken to investigate the relationship between stem elasticity and femoral bone stress shielding.
The stems used were the Isoelastic Stem (Robert Mathys Co.) and the Osteonics titanic femoral prostheses, whose coefficients of elasticity are very different, as is well known. Isoelastic Stems were inserted in 7 males and 8 females, 8 patients with coxarthrosis and 7 patients with aseptic necrosis of the femoral head (ANF), while Osteonics titanic stems were inserted in 9 males and 9 females, 11 patients with coxarthrosis and 7 patients with ANF. Those in the Isoelastic group averaged 54.3 years in age (43 to 66), and those in the titanic 51.6 years (19 to 66) . Prior to surgery, patients were examined to see whether they had bone cortex of sufficient thickness to bear non-cement type stems, and those with it were randomized into Isoelastic and titanic prosthesis groups. The patients were observed for 5.5 years on an average.
According to the zone classification of Gruen et al., in postoperative patients in the Isoelastic group, bone reaction such as thinning or thickening of the bone cortex was absent in all but one, and stem loosening was observed also in only one. In the titanic group, on the other hand, bone cortex thinning apparently due to stress shielding in zones 6 and 7 was observed in A-P projections in 16 of 17. Furthermore, stress shielding in zone 1 and bone cortex thickening in zones 3 to 5 was observed in lateral projections with high frequency in all patients.
Stress shielding was thus often observed in the inner aspect of the calcar area of the femur in cases where titanic stems of high rigidity were used, while stress shielding did not occur with Isoelastic stems of low elasticity. These results suggest that hip joint protheses of the lowest possible elasticity will provide stems which are effective in the prevention of stress shielding, both theoretically and clinically.

抄録全体を表示

One hundred-and-five knees (75 patients) with rheumatoid arthritis received Yamamoto Mark III total knee replacement in our hospital from 1987 to 1992. Bone graft was used on 58 knees which had severe bone defect or bone atrophy. Fifty of these 58 knees could be followed for more than one year. Eighteen had had a trapezoidal bone graft because of a large bone defect of the tibial plateau, 22 a bone chips graft because of bone atrophy or bone cyst of the tibia, 3 a trapezoidal bone graft on the femur, and 17 a bone chips graft on the femur side.
Clinical results as represented by JOA score were satisfactory. X-ray findings showed complete bone union in all cases. But sinking of the tibia component was observed in 28 knees, especially in 16 knees with bone chips graft of the tibia. Loosening of the femoral component was observed in 4 knees.

抄録全体を表示

Serum samples from 57 patients who were diagnosed as having early rheumatoid arthritis (RA) were examined for antibodies against native human Type II collagen by enzymelinked immunosorbent assay (ELISA) . Antibodies were detected in 43 patients (75.4%) . Follow-up studies (more than 3 years) demonstrated that 29 patients subsequently had a positive test for rheumatoid factors. The levels of anti-Type II collagen antibodies tended to be more elevated just before the appearance of active arthritis and were low or not detected during the chronic phase. When 14 seronegative patients showing monoarthritis of the hip, knee or elbow joint were examined, 12 were positive for the antibodies. These patients were found to develop chronic polyarthritis eventually and to be positive for rheumatoid factors during the course of the disease. These results suggest that the immunization against Type II collagen seems to be functionally active in RA, and that antibodies assay may serve a supportive purpose for the diagnosis of the disease.

抄録全体を表示

We examined the long-term outcomes and limitations of occipito-atlantoaxial fusion for cervical lesions of rheumatoid arthritis (RA) . This study involved 10 patients (2 males and 8 females) who underwent the modified Brattstrom method from 1978 to 1992. The mean RA prevalence period was 15.4 years (8-33 years), the mean age at operation was 61.3 years, and the mean follow-up period was 51 months.
Seven of the 10 cases died an average of 3.3 years after the operation. In all cases the fusion operation was successful and there was almost no failure of correction. However, activity of daily living and neural symptoms deteriorated over a long term. The deterioration was thought to be due to the exacerbation of articular symptoms and to the progression of subluxation of the spine below the fusion in mutilans type RA. These findings should be investigated further with a larger population.

抄録全体を表示

In order to better understand the important factors related to successful long term (over 10 year) results following O'Malley's muscle release surgery, we evaluated X-ray findings before and after it. Until 1982 it was performed on 32 hips of 26 patients with osteoarthrosis. Twenty one of these patients (27 hips) were divided into 4 groups. Group 1 (9 hips) had had no pain for over 10 years. Group 2 (10 hips) had had almost no pain for more than 6 years following surgery and still had less pain than before surgery. In Group 3a (4 hips), pain did not decrease, and THA was performed within 5 years of the surgery. In Group 3b (4 hips), pain decreased during the early years, but then recurred, and THA was performed more than 5 years after surgery.
The joint space, Sharp angle, acetabular head index (AHI), modified acetabular depth, and length of roof osteophyte were measured from X-ray films taken prior to surgery, and 1 and 3 months, and 1 and 3 years following surgery. The factor most closely related to successful results was joint space. In Groups 1 and 2, the joint space had definitely enlarged 3 months after surgery. In contrast, the joint space remained narrow in all of the Group 3a cases. The Sharp angle and AHI were not different among the 4 groups. In Group 3a, no roof osteophytes were found and modified acetabular depths were less than those in the other groups.

抄録全体を表示

Surgical repair of a massive rotator cuff tear is one of the most difficult problems in shoulder surgery. Occasionally the torn cuff edge cannot be pulled out enough to anchor around the humeral tuberosity with McLaughlin's technique. Teflon felt was used to repair such a condition in 9 joints of 8 patients. The mean follow-up period was one year, seven months.
The average JOA score was elevated to 92.8 after surgery from 43.4 before. The acromiohumeral interval was 4.5 mm on an average before surgery and 8.2 mm afterwards. While the follow-up periods have not been long yet, the short-term results have been excellent. For ease in performing surgery and expectation of being able to get good clinical results, we recommend this technique as a procedure for reconstruction of massive rotator cuff tears.

抄録全体を表示

Bipolar hip arthroplasty was performed without bone graft on 15 hips of 13 RA patients with acetabular cartilage which conserved the surface without destruction. The mean age was 58 years (range 44-76), and the mean disease duration was 17.4 years (range 3-59) . Postoperative observation was done for a mean of 3.1 years (range 5 months-5 years) . We analyzed the clinical features using the hip rating score of the Japanese Orthopaedic Association and the Lansbury Index. Furthermore, we assessed roentogenographic features by measuring the KC length, which indicates medial migration, the TC length, which indicates upward migration of the outer head, and the CE angle.
Improvement of hip score was obtained postoperatively. The Lansbury Index did not change dramatically during the five years after the operation. The KC length decreased in 36% of the patients, and the TC length increased in 58%, with 27% showing an increase of more than 5° in the CE angle. These results may indicate that bipolar hip arthroplasty for RA patients who had had intact acetabular cartilage induced medial and upward migration of the outer head in some cases. But since other cases did not show any medial and upward migration for five years, we must study the etiology of such migration and determine more precisely the indication of bipolar hip arthroplasty without bone graft for RA patients.

抄録全体を表示

From 1987 to 1992, arthroscopic synovectomy was performed on 78 knees in 50 patients with rheumatoid arthritis. The clinical results of 27 knees in 20 patients, 19 females and 1 male, who were followed up at least 2 years are reported. Their average age was 59.5 years and the average follow-up period was 47 months. Ten knees (37.0%) needed re-synovectomy during the follow-up period. All knees were evaluated by JOA score and Larsen's X-ray grading.
After arthroscopic synovectomy, the JOA score was improved (p<0.05) and pain remarkably so (p<0.001), but other scores were unchanged. X-ray films showed that slight rheumatoid changes had progressed in 11 knees (40.7%) . Although there were some cases of re-operation, arthroscopic synovectomy for rheumatoid knee joint is useful when arthritis cannot be controlled by medication.

抄録全体を表示

Only a few cases of a clinically significant pigmented villonodular synovitis-like lesion (PVS-like lesion) following total knee replacement (TKR) have been reported. Here we describe a woman with osteonecrosis of the medial femoral condyle of the right knee, in whom a PVS-like lesion developed after TKR of the involved knee. The type of artificial knee used was a Yamamoto Mark II. Seven years after the knee replacement, her varus deformity appeared and X-rays revealed progressive osteolytic change in the medial tibial portion, necessitating re-operation with a cemented Omnifit type prosthesis. Pathological findings of the resected synovia, which was totally black in color, were consistent with those of PVS. Ten months have passed since the second operation, and the prosthesis has remained stable thus far.

抄録全体を表示