PubMed Health⌕ Search

Biomedical subjects

S Uta

Publications and source records attributed to S Uta.

10 recordsLinked to original sources
PubMed2002

Hamatometacarpal fracture-dislocation: distinctive three dimensional computed tomographic appearance.

We report here two fully documented cases of hamatometacarpal fracture-dislocation following trauma and treated in our hospital. In our cases, the patients suffered hamate fracture in association with metacarpal dislocation. In the first case, a dorsal oblique fracture of the hamate was associated with a dorsal dislocation of the base of the fourth metacarpal. In the second case, a dorsal oblique fracture of the hamate was not associated with a dorsal dislocation of the base of the fifth metacarpal. This diagnosis should be suspected on initial review of plain radiographs, which must include an oblique view because of diagnostic difficulty for this injury. We recommend three dimensional computed tomography (3D-CT) in any patient presenting with pain after blunt trauma to the hand to prevent in diagnosis. Open reduction and internal fixation of the fracture is indicated and relevant for displaced fracture.

Adult↗
PubMed2000

The initial fixation of the press-fit acetabular shell--clinical observation and experimental study.

The initial solid fixation of an uncemented acetabular component affects the amount of bone ingrowth. We had several problems with broken screws in cases of acetabular revision. In recent years, the development of uncemented components without screws has attempted to improve these problems. We started to use "press-fit"-type acetabular shells in November 1996. Our thirty cases undergoing 2 mm under-reaming show good initial stability. The aim of our biomechanical study was to assess the most suitable degree of under-reaming of the bony acetabulum for the implantation of an uncemented hemispherical porous coated component.

Acetabulum↗
PubMed1999

Lumbar spinal synovial cyst presenting with neurological deficit. A case report and review of the literature.

A spinal synovial cyst is a rare condition. We reported a case of lumbar spinal synovial cyst presenting neurological deficit. A 78-year-old woman was admitted to our hospital with the low back pain radiating to the left buttock. A myelography with computed tomography and magnetic resonance imaging revealed an extradural cystic lesion at the L5 and S1 level. At the time of surgery, a standard posterior approach was used to expose the posterior elements from L5 to S1. An en bloc laminectomy and total removal of the cyst was performed at the L5 to S1 level. The postoperative recovery was uneventful except for a slight pain in the left leg which persisted for some time.

Aged↗
PubMed1992

[A new intramedullary nailing system for long bone fractures--biomechanical evaluation and animal study of a new intramedullary nail].

Interlocking intramedullary nails have expanded their application to the fixation of long bones especially for unstable or comminuted fractures. However, there are certain drawbacks in this method: prolongation of operative time and increased radiation hazard to the patient as well as to the surgical staff, the latter of which is especially a problem in the distal interlocking under fluoroscopic control. In order to solve the problem a new intramedullary nail (J-type) was developed and tested in vitro with Hiprox femur models as well as in vivo using canine models. The nail made of Ti-6Al-4V alloy is composed of an inner nail and an outer cylinder. The proximal portion is transversely fixed with two screws, while the distal portion is fixed into the cancellous bone with four expandable blades. The strength of fixation with this nail was compared to those with four other commercially available interlocking nails as to bending, tortional and compression stiffness as well as to the durability against repeated compression. In the present in vitro and in vivo experiments, a newly developed intramedullary nail (J-type) provides evidence for satisfactory mechanical strength. The use of J-type nail also contributes to shorter operative time and reduction of radiation hazard.

Animals↗
PubMed1992

[Development of synthetic bone models for the evaluation of fracture fixation devices].

Mechanical tests are indispensable for the research and development of internal devices used for fracture fixation. It is ideal to use fresh human bones even for in vitro experiments. However, fresh human bones are difficult to access, so that alternative materials have been developed. In this study, the applicability of synthetic tibia or femur models made from polyurethane resin (Hiprox) was studied, comparing the mechanical properties of both the synthetic models and the fresh human bones under fracture-fixation conditions using various fixation devices. When the models were designed to simulate the cortical bone with solid resin and the cancellous bone with porous resin, the mechanical properties can be fairly approximated to those of the fresh human bones. It was concluded that the Hiprox models are useful in for preliminary testing of fracture fixation devices.

Biomechanical Phenomena↗