Masaru Kitajima

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 10−5 M 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.

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 24 h, 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.

Failure analysis of alumina on alumina total hip arthroplasty with a layered acetabular component: minimum ten-year follow-up study.

This prospective study reports the outcome of total hip arthroplasty (THA) performed in a consecutive series of patients using an alumina ceramic on a ceramic-layered component (Alumina-Bearing-Surface system). The cohort consisted of 270 hips in 229 patients. The study evaluated the clinical and radiological results over a mean follow-up of 11.4 years. Revision THA was performed on 58 hips, including alumina alternative failure in 50 hips, loosening in 4 hips, recurrent dislocation in 2 hips, stem neck fracture in 1 hip and hematoma in 1 hip. The survival rate was 68% with revision for any reason as the end point. The risk factors of implant failure are the preoperative range of motion of the hip joint and postoperative dislocation.

Seasonal trends in the incidence of hip osteoarthritis in Japanese patients.

Purpose: There is an association between winter birth and developmental dysplasia of the hip, formerly termed congenital dislocation of the hip. The purpose of this study was to clarify the relationship between the month and season of birth and hip osteoarthritis in Japanese patients who had undergone total hip arthroplasty or transpositional osteotomy of the acetabulum. Methods: One thousand eight hundred and 52 female patients that presented for the surgical treatment of hip osteoarthritis between 1999 and 2005 were included in this study. Female out-patients who were seen at the initial visit during same period were used as controls to correct the bias of the month of birth. Results: There was a significant deviation of the observed number of births from the expected values calculated on a monthly basis (p<0.001). A comparison by seasons (periods of 3 months) revealed more births than expected in winter (p<0.001). The risk of hip osteoarthritis was significantly associated with the month of birth. Namely, it was highest for births in January (p<0.001). Conclusions: These data clearly revealed that the prevalence of hip osteoarthritis was significantly higher in those patients born in winter. The seasonal trend in hip osteoarthritis might be due to the winter prevalence of congenital dislocation of the hip in childhood.

Nerve Palsy after Total Hip Arthroplasty without Subtrochanteric Femoral Shortening Osteotomy for a Completely Dislocated Hip Joint

Background: Neurological injuries are a rare but devastating complication after total hip arthroplasty (THA). The purpose of this study was to retrospectively determine the frequency of nerve palsy after THA without subtrochanteric femoral shortening osteotomy in patients with a completely dislocated hip joint without pseudo-articulation between the femoral head and iliac bone. Methods: Between October 1999 and September 2001, nine primary THAs were performed for patients with a completely dislocated hip joint. The limb lengths, neurological abnormalities, and the extent of their neurological recovery were evaluated. Three THAs were combined with subtrochanteric femoral shortening osteotomy, and six THAs were combined without subtrochanteric femoral shortening osteotomy. Results: The mean length of the operation was 4.8 cm (range, 3.0-6.5 cm). Sciatic nerve palsy developed in four of the nine patients after THA. None of the cases with sciatic nerve palsy were combined with subtrochanteric femoral shortening osteotomy. Three of four patients did not completely recover from sciatic nerve palsy. Conclusions: THA for patients with a completely dislocated hip was associated with a high risk of nerve palsy due to excessive limb lengthening; the potential for recovery from nerve palsy was observed to be poor. Subtrochanteric femoral shortening osteotomy should be used in combination with THA in patients with a completely dislocated hip.

Wear of XLPE liner against zirconium heads in cementless total hip arthroplasty for patients under 40 years of age

Introduction Total hip arthroplasty (THA) in the young is challenging. The purpose of this study was to retrospectively determine the clinical, radiographic, and polyethylene wear rate of relatively young patients. Methods We evaluated the outcome of consecutive patients receiving primary THA who were under 40 years of age with a minimum 10-year follow-up. Indications for THA in these patients were osteoarthritis due to developmental dysplasia of the hip joint (9 hips), osteonecrosis of the femoral head (7 hips), juvenile idiopathic arthritis (2 hips), and osteoarthritis due to Perthes disease (1 hip). All THA were performed with a cross-linked ultra-high-molecular-weight polyethylene (XLPE) liner against zirconium heads with cementless implants. Results The average Japanese Orthopaedic Association hip score significantly improved from 42 to 93 points at the latest follow-up. The mean steady wear was 0.015 mm/year (maximum 0.033 mm/year), and the mean creep wear was 0.111 mm (maximum 0.4 mm). Osteolysis was observed around 1 acetabular component and 2 stems. 1 femoral component had subsidence over 5 mm. All of the femoral components achieved fixation with an optimal interface with spot welds at the latest follow-up. Stress shielding was observed in all hips. Conclusions THA using an XLPE liner against zirconium heads appeared to have improved THA longevity. However, the imaging findings in some cases were suggestive of wear debris. A rigorous continual follow-up is required for relatively young patients undergoing THA.

Total Hip Arthroplasty for the Paralytic and Non-paralytic Side in Patient with Residual Poliomyelitis

Background: Total hip arthroplasty (THA) for poliomyelitis is a problematic procedure due to difficulty in positioning the cup of the prosthesis in the true acetabulum and the risk of dislocation after THA due to the low muscle tone. Methods: We herein present a case of bilateral hip pain with a history of poliomyelitis. Radiograph showed bilateral hip osteoarthritis caused by hip dysplasia due to residual poliomyelitis in right hip joint or developing dysplasia of the hip joint in left hip joint. THA was performed to bilateral hip joints. Results: Six years after bilateral THA, bilateral hip pain significantly improved. Additionally, the muscle strength on the paralyzed right side partially improved. However, the muscle strength on the non-paralyzed left side did not significantly improve. No complications related to the surgery were observed. Conclusion: Promising early results were obtained for THA in our patient with residual poliomyelitis. However, surgeons should pay attention to the potential development of complications concerning THA that may arise due to the residual poliomyelitis.

Acute Hematogenous Infection of Revision Total Hip Arthroplasty by OralBacteria in a Patient without a History of Dental Procedures: Case Report

The risk of periprosthetic joint infection from hematogenous bacterial seeding is increased in patients undergoing dental procedures that facilitate the development of bacteremia. We herein report the case of a patient without a history of dental procedures who suffered from an acute metastatic infection of a hip prosthesis by the oral bacterium Streptococcus mutans 18 months after undergoing revision total hip arthroplasty. The patient was successfully treated by two-stage revision surgery. It is important to realize that the efficacy of antibiotic prophylaxis against joint infections has not yet been convincingly proven. As a result, optimal dental hygiene and regular dental visits may be more important than antibiotic prophylaxis for maintaining joint health. Therefore, orthopedic surgeons should educate patients with joint prostheses about good oral health.

Subcutaneous Achilles tendon rupture in an eighty-year-old female with an absence of risk factors

Achilles tendon ruptures rarely occur in patients over 80 years of age. However, it is unclear what treatment, surgical or conservative, is suitable for such an Achilles tendon rupture in the elderly. In addition, the clinical results of an Achilles tendon rupture in the elderly are disappointing. We report here the case of a subcutaneous Achilles tendon rupture in an eighty-year-old, healthy female, who returned to her previous level of activity following surgical treatment. Additional case reports of other instances of successful treatment are needed to help establish the optimal treatment protocol for an Achilles tendon rupture in the elderly.

Risk Factors for the Development of Nerve Palsy Following Primary Total Hip Arthroplasty

Background: Nerve palsy following total hip arthroplasty (THA) is a complication that worsens the functional prognosis. The present study analyzed the risk factors of nerve palsy following THA. Methods: The subjects of this study included 6,123 cases in which primary THA was performed under spinal anesthesia with cementless implants used in the posterolateral approach. Results: Fourteen cases (0.22%) developed nerve palsy following THA, all of which involved palsy of the entire peroneal nerve region. The diagnoses included osteoarthritis due to subluxation (n=6), complete hip dislocation (n=3), osteonecrosis of the femoral head (n=2), primary osteoarthritis (n=1), osteoarthritis due to trauma (n=1), and multiple osteochondromatosis (n=1). Recovery from nerve palsy was confirmed in 10 cases; the longest recovery period was three years. A univariate analysis revealed significant differences in the osteoarthritis due to subluxation, osteonecrosis of the femoral head, complete hip dislocation, body weight and body mass index. However, none of the factors remained significant in multivariate analysis. Peroneal (ischiadic) nerve palsy following THA occurred in patients with osteonecrosis of the femoral head, complete hip dislocation, low body weight and a low body mass index. However, there were no cases of nerve palsy after the introduction of THA combined with shortening osteotomy of the femur for complete hip dislocation. patients. Conclusion: It is necessary to pay attention to direct pressure in cases of lower body weight and lower BMI because compression of the sciatic nerve during surgery and compression of the fibular head are considered to be risk factors.