Yoichi Sugioka

Transtrochanteric anterior rotational osteotomy for idiopathic and steroid-induced necrosis of the femoral head. Indications and long-term results.

From 1972 until 1988, transtrochanteric rotational osteotomy was used to treat 474 hips in 378 patients with idiopathic and steroid-induced osteonecrosis of the femoral head. Two hundred twenty-nine of 295 hips with anterior rotation and follow-up periods ranging from three to 16 years had excellent surgical results (success rate, 78%). Outcome was chiefly dependent on the ratio of transposed intact posterior articular surface to the acetabular weight-bearing area after osteotomy. This relationship suggested that the transposed intact area should occupy more than 36% of the acetabular weight-bearing area by adequate rotation and intentional varus position in addition to rotation, especially for extensive lesions. Salvage operations, such as total hip arthroplasty, were performed on 18 hips, of which ten hips were cases of either relative indication for extensive lesions in young patients or other misindications for rotational osteotomy. Four hips sustained neck fracture, including three hips after 180 degrees of posterior rotation; two hips were complicated with avascular necrosis, and another two hips developed osteoarthrosis. Histologically, femoral heads with osteoarthrosis removed at the time of salvage operation showed complete healing of the necrotic lesion. The overall findings indicate that healing of the necrotic lesion of the femoral head may be brought about by rotational osteotomy if it spares the vulnerable site from the brunt of mechanical stress.

Evaluation of the risk of instrumentation as a foreign body in spinal tuberculosis. Clinical and biologic study.

The risk of persistence and recurrence of infection in posterior spinal instrumentation surgery for spinal tuberculosis was studied clinically and microbiologically. Eleven patients with thoracic, thoracolumbar, and lumbar spinal tuberculosis treated by debridement, anterior fusion, and combined posterior instrumentation surgery were analyzed. Seven patients had tuberculosis in both anterior and posterior spinal elements. There were no cases of persistence or recurrence of infection after surgery, and instrumentation provided immediate stability and protected against development of kyphotic deformity. The adherence properties of Mycobacterium tuberculosis to stainless steel (SUS 316) was evaluated experimentally. The results showed that posterior instrumentation surgery was not a hazard to spinal tuberculosis infection when combined with radical debridement and intensive anti-tuberculosis chemotherapy.

Influence of alcohol intake, cigarette smoking, and occupational status on idiopathic osteonecrosis of the femoral head.

An epidemiologic study compared 112 patients with idiopathic osteonecrosis (ON) of the femoral head having no history of systemic corticosteroid use and 168 hospital controls. Patients and controls were matched for gender, age, ethnicity, hospital, and time of initial diagnosis. The role of alcohol intake, cigarette smoking, and occupational status was assessed in relation to the development of ON. The relative risk (RR), the measure of association between ON and the risk factors, was statistically adjusted for the potential confounding effects of other factors by the conditional logistic regression model. An elevated risk for regular drinkers (RR = 7.8, p < 0.001) and a clear dose-response relationship was noted (test for trend; p < 0.001): the RRs were 3.3, 9.8, and 17.9 for current consumers of <400, 400–1000. and ≤000 ml/week of alcohol, respectively. A significantly increased risk was found for current smokers (RR = 3.9; p < 0.05). However, the cumulative effect of smoking was not evident. No increased risk was found for obesity or for heavy physical work. Regarding causation of ON, this study confirmed the consistent association with excessive alcohol intake and suggested the immediate untoward effects of smoking. The role of heavy physical work as a form of mechanical stress was not correlated with ON.

Localization and quantification of proliferating cells during rat fracture repair: detection of proliferating cell nuclear antigen by immunohistochemistry.

Bilateral femurs of 12‐week‐old female Sprague‐Dawley rats were fractured, and the fractured femurs were harvested 36 h, 3, 7, 10, and 14 days after the fracture. Localization of cell proliferation in the fracture calluses was investigated using immunohistochemistry with antiproliferating cell nuclear antigen (PCNA) monoclonal antibodies. Thirty‐six hours after the fracture, many PCNA‐positive cells were observed in the whole callus. The change was not limited to mesenchymal cells at the fracture site where the inflammatory reaction had occurred, but extended in the periosteum along almost the entire femoral diaphysis where intramembranous ossification was initiated. On day 3, periosteal cells or premature osteoblasts in the newly formed trabecular bone during intramembranous ossification still displayed intense staining. On day 7, many premature chondrocytes and proliferating chondrocytes were PCNA positive. Endochondral ossification appeared on days 10 and 14, and the premature osteoblasts and endothelial cells in the endochondral ossification front were stained with anti‐PCNA antibodies. Quantification of PCNA‐positive cells was carried out using an image analysis computer system, obtaining a PCNA score for each cellular event. The highest score was observed in the periosteum early after the fracture near the fracture site. Immunohistochemistry using anti‐PCNA antibodies showed that the distribution of proliferating cells and the degree of cell proliferation varied according to the time lag after the fracture, suggesting the existence of local regulatory factors such as growth factors, and that significant cell proliferation was observed at the beginning of each cellular event.

Corticosteroid Enhances the Experimental Induction of Osteonecrosis in Rabbits With Shwartzman Reaction

Bacterial endotoxic reactions can cause osteonecrosis in humans by disseminated intravascular coagulation. The authors first used a combination of the Shwartzman reaction and corticoid injections in rabbits to develop a new animal model of osteonecrosis. This model showed a significantly higher incidence and wider area of osteonecrosis in the femur and humerus than that found in rabbits with either Shwartzman reaction or steroid injection alone. Osteonecrosis was observed in several foci that were distributed from the diaphysis to the epiphysis in both bones. Histologically, the bone marrow cells underwent necrosis, whereas the bone trabeculae demonstrated either empty lacunae or pycnotic nuclei of osteocytes. Exogenous steroids appeared to potentiate the Shwartzman reaction and the magnitude of osteonecrosis, perhaps by increasing endothelial damage and hypercoagulability of those intraosseous and extraosseous vessels that subsequently thrombosed. This model may not only be useful in clarifying the etiology and early pathogenesis of human osteonecrosis after corticoid therapy, but also in designing Pharmaceuticals for prevention and early treatment.

Hydroxyapatite‐coating on titanium arc sprayed titanium implants

We developed a new titanium spray technique using an inert gas shielded arc spray (titanium arc spray). Hydroxyapatite (HA)-coating can be applied to the implant without any surface pore obstruction after the rough surface is made by this technique. Scanning electron microscopy (SEM) of various porous implant surfaces after HA-coating revealed that the bead and fiber metal-coated implants had either a pore obstruction or an uneven HA-coating. On the other hand, the titanium arc sprayed implant demonstrated an even HA-coating all the way to the bottom of the surface pore. In the first set of animal experiments (Exp. 1), the interfacial shear strength to bone of four kinds of cylindrical Ti-6A1-4V (Ti) implants were compared using a canine transcortical push-out model 4 and 12 weeks after implantation. The implant surfaces were roughened by titanium arc spray (group A-C) and sand blasting (group D) to four different degrees (roughness average, Ra = group A: 56.1, B: 44.9, C: 28.3, D: 3.7 microns). The interfacial shear strength increased in a surface roughness-dependent manner at both time periods. However, the roughest implants (group A) showed some failed regions in the sprayed layers after pushout test. In the second set of animal experiments (Exp. 2), four kinds of Ti implants; HA-coated smooth Ti (sHA) with Ra of 3.4 microns, bead-coated Ti (Beads), titanium arc sprayed Ti (Ti-spray) with Ra of 38.1 microns and HA-coated Ti-spray (HA + Ti-spray) with Ra of 28.3 microns were compared using the same model as that in Exp. 1. The interfacial shear strength of HA + Ti-spray was significantly greater than that of sHA and Beads at both time periods, and that of Ti-spray at 4 weeks. Although a histological examination revealed that HA-coating enhanced bone ingrowth, sHA showed the lowest shear strength at both time periods. SEM after pushout test showed that sHA consistently demonstrated some regional failure at the HA-implant substrate interface. HA + Ti-spray had many failed regions either at the HA-bone interface or within the bone tissue rather than at the HA-implant substrate interface. These results suggested that the HA-coated smooth surfaced implants had a mechanical weakness at the HA-substrate interface. Therefore, HA should be coated on the rough surfaced implants to avoid a detachment of the HA-coating layer from the substrate and thus obtain a mechanical anchoring strength to bone. HA-coating on this new type of surface morphology may thus lead to a solution to the problems of conventional HA-coated and porous-coated implants.

Limb allografts in rats immunosuppressed with FK506. I: Reversal of rejection and indefinite survival

We have tested the effects of FK506 (FK), a new immunosuppressive agent, on a rat limb allograft model. Histoincompatible BN limb allografts were rejected in untreated F344 hosts within 11±1 days (mean ± SD) after operation. A single injection of 2 mg/kg, 10 mg/ kg, or 50 mg/kg of FK on the day of limb transplantation (day 0) significantly prolonged graft survival in a dose-dependent manner—i.e., mean limb survival times (MST) based on gross signs of skin rejection were 16±3 days, 51 ±6 days, or 104±17 days, respectively (P < 0.01). Delayed treatment with a single injection of 10 mg/kg of FK at when early signs of rejection were visible (day 7 or day 10) reversed the ongoing rejection. The MSTs in these groups were comparable to that of those treated with the same dosage of FK on day 0. The FK-induced unresponsiveness toward limb allografts was donor-specific because limb-allografted, FK-protected rats could not accept the skin grafts from a third-party donor. In the next set of experiments, rats were given a single administration of 10 mg/kg of FK on the day of limb allograft, followed by intermittent injections of 3 mg/kg of FK once a week. This regimen produced complete graft survival for more than 200 days, though Pneumocyatis carinii pneumonia occurred in most of the recipients. These results represent the unique effects of FK in preventing or reversing the graft rejection and in inducing indefinite survival in this animal model of composite tissue allografts.

Transtrochanteric rotational osteotomy of the femoral head for the treatment of osteonecrosis. Follow-up statistics.

Transtrochanteric rotational osteotomy of the femoral head was technically established as a surgical procedure in 1972. This procedure has been successfully performed on 250 hips in 204 patients. In the treatment of idiopathic and steroid-induced osteonecrosis of the femoral head, the results of 128 hips in 90 patients followed two to nine years were reviewed. In 98 of 128 hips, excellent results were obtained clinically and roentgenographically. Progressive collapse in the newly created weight-bearing area occurred in 25 hips where the lesions had been extensive. In 35 of 39 Grade I or II hips, excellent results were obtained in every respect (success rate: 90%). Following the analysis of results on the preoperative lateral roentgenograms of the femoral head, 76 of the 80 hips in the group in which the intact area was greater than one third of the total articular surface showed no collapse of the newly created weight-bearing area, thus accounting for a 95% success rate. In cases when a further collapse was prevented, the necrotic lesions were smaller at follow-up. Excellent results were obtained when the osteotomy was performed during the early stage of necrosis and in the absence of an advanced collapse, even in extensive lesions. In advanced cases with an extensive lesion, adequate anterior rotation is essential and intentional varus position should be designed. These results suggest that this procedure will inhibit progressive collapse of the femoral head and restore the joint more effectively than other surgical procedures.

The role of MR imaging in the diagnosis of alveolar soft part sarcoma-a report of 10 cases

ObjectiveThe objective of this study was to analyze the characteristics of alveolar soft part sarcoma using magnetic resonance imaging (MRI).DesignMRI studies of pathologically proven alveolar soft part sarcomas (ASPS) in ten patients were reviewed and compared with computed tomographic (CT) studies and angiograms.PatientsTen patients presented with a soft tissue mass of the extremities, neck, axilla, or buttocks. MR images were obtained in all patients prior to surgical intervention, chemotherapy, or irradiation.Results and ConclusionAlthough most soft tissue sarcomas are isointense relative to muscle on MRI T1-weighted images (T1WI), nine of the ten alveolar ASPS in the present study demonstrated high signal intensity on both T2 and T1WI. Flow voids were observed both at the core and at the margins of the tumors studied. Recognition of these characteristic MRI findings may lead to the early diagnosis of ASPS, especially when the clinical presentation is that of a slow-growing soft tissue mass in a young adult patient.

Remodelling of bone around hydroxyapatite and titanium in experimental osteoporosis

The affinity of the tibia bone for cylinders of hydroxyapatite (HA) and Ti-6Al-4V was investigated in three experimental animal models: intact rat tibiae, ovariectomized rat tibiae and ovariectomized plus neurectomized rat tibiae. The affinity index (the length of bone directly apposed to the implant/the total length of the bone-implant interface x 100%) was calculated. In intact and ovariectomized tibiae, no significant difference existed between the affinity index of HA and Ti-6Al-4V. In ovariectomized plus neurectomized tibiae, the affinity index of HA was greater than for Ti-6Al-4V from 8 to 24 wk after implantation (8 wk, P < 0.05; 12 wk, P < 0.005; 24 wk, P < 0.05). The affinity index of Ti-6Al-4V in normal tibiae was greater than that in ovariectomized or ovariectomized plus neurectomized tibiae. There was no significant difference of the affinity index of HA between normal, ovariectomized or ovariectomized plus neurectomized tibiae. Osteoporotic bone demonstrated a greater affinity to HA than Ti-6Al-4V in an experimental animal model.