Masamori Shigematsu

Factors influencing the improvement of gait ability after total hip arthroplasty.

We aimed to investigate the factors influencing gait improvement in the patients who had undergone total hip arthroplasty. We performed gait analysis on 43 female patients with unilateral hip osteoarthritis. All the patients were analyzed before and at 2, 6, and 12 months after the surgery. There were significant reductions in spatiotemporal parameters in the patients with hip osteoarthritis compared with the control group. The mean values of the spatiotemporal parameters of the patients showed considerable improvement by 12 months after surgery; however, they did not reach the same values as those observed in the healthy subjects. The stage of osteoarthritis and the changes in the leg-length discrepancies were the factors that most influenced gait improvement after total hip arthroplasty throughout the follow-up period.

Effects of glucocorticoid on adipocyte size in human bone marrow

The pathogenesis of corticosteroid-induced femoral head necrosis is assumed to be related to lipid metabolism. Mature fat cells are believed to play a central role in lipid metabolism. The purpose of this study was to investigate the size of mature fat cells in the human femoral head after steroid treatment. Cancerous bone tissue was obtained from the femoral heads of 20 women who had undergone total hip arthroplasty. This bone tissue was subsequently incubated in a medium containing 10−7 or 10−5u2009M dexamethasone for 5 days. Mature fat cells from the bone marrow were observed by scanning electron microscopy, and the largest diameter of individual fat cells was measured. The size of the mature fat cells in human bone marrow increased after high-dose steroid treatment. The largest fat cell volume after steroid treatment was one and one-half times larger than that observed in the control. Steroid-induced osteonecrosis is known to sometimes occur after high-dose steroid treatment. These findings may indicate the pathogenetic factors in the early stage of steroid-induced osteonecrosis.

Effectiveness of autologous fibrin tissue adhesive in reducing postoperative blood loss during total hip arthroplasty: a prospective randomised study of 100 cases

Purpose. To evaluate the effectiveness of autologous fibrin tissue adhesive (auto-FTA) in reducing blood loss during cementless total hip arthroplasty (THA). Methods. From September 2000 to August 2001, 100 patients who predonated 400 ml of autologous blood were randomised to undergo either standard treatment with auto-FTA (auto-FTA group) or standard treatment alone (control group). The volume of postoperative blood loss and the decrease in haemoglobin level were measured. All patients were followed up for 3 years to evaluate the rate of bone ingrowth and heterotopic ossification. Results. The mean postoperative blood loss was 580 ml (standard deviation [SD], 240 ml) in the auto-FTA group and 810 ml (SD, 341 ml) in the control group; the difference was significant (230 ml, p<0.001). The decrease in haemoglobin concentration was 17 g/l (SD, 11 g/l) in the auto-FTA group and 22 g/l (SD, 12 g/l) in the control group. The difference was significant (5 g/l, p=0.03). The percentage of total blood loss of >1200 ml in any single patient was significantly lower in the auto-FTA group (4%) than in the control group (20%) [p=0.01]. Conclusion. Auto-FTA is a safe and effective means of reducing perioperative blood loss in THA.

Changes in the WOMAC, EuroQol and Japanese lifestyle measurements among patients undergoing total hip arthroplasty

OBJECTIVEnTo assess changes in the health outcomes of Japanese patients before and after total hip arthroplasty (THA), and to assess the impact of THA on commonly performed postures or body positions requiring deep flexion of the hip joint such as the use of Japanese squat toilets.nnnMETHODSnConsecutive patients undergoing primary THA between July 2003 and July 2004 were eligible for the study. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the EuroQol 5D (EQ-5D) were administered at the preoperative period and two postoperative periods of 6 weeks and 6 months. The patients were also asked to rate three items regarding common activities of daily living in Japan such as squatting. Changes in scores were examined using effect size and proportion at the floor and ceiling.nnnRESULTSnFour-hundred and fifty-one patients completed both pre- and post-THA surveys. Significant improvements in pain and physical function as measured by WOMAC and EQ-5D were evident within 6 weeks. Changes in WOMAC and EQ-5D subscale scores and scores for each item from the three time periods were highly significant (P=0.000). The effect size was 1.56 for WOMAC pain and 1.38 for physical function at 6 months. In contrast, two items (Japanese toilet and seiza) became significantly worse at the 6-week postoperative period (P=0.000) and returned to preoperative levels by the 6-month postoperative period.nnnCONCLUSIONnThese results highlight the importance of evaluating culturally sensitive physical functions in addition to conventional measurements for the health outcomes of THA patients.

Mature and activated osteoclasts exist in the synovium of rapidly destructive coxarthrosis

We compared histological and functional findings in rapidly destructive coxarthrosis (RDC) and slowly progressive osteoarthritis (OA) to investigate whether osteoclasts contribute to the extensive bone destruction observed in RDC. A histological analysis of tissue specimens from the synovium obtained from 10 cases of RDC and 40 cases with OA of the hip was performed after staining for tartrate-resistant acid phosphatase (TRAP). The cells isolated from these tissue specimens from the synovium were cultured for 24u2009h, and the numbers of TRAP-positive giant cells were counted. Thereafter, we performed a resorption pit formation assay by isolated cells cultured on dentine slices for 7 days. The number of TRAP-positive multinuclear giant cells present in the synovial membrane obtained from RDC patients was significantly larger than that obtained from OA patients. Large lacunar resorption pits were only seen on the dentin slices in a culture of isolated cells from RDC patients without any stimulators. This is the first report, to our knowledge, to reveal that mature and activated osteoclasts exist only in the synovium of RDC and not in the OA synovium. This result might suggest that the underlying mechanism of RDC is therefore associated with osteoclastogenesis in the synovium.