Biomedical subjects

Shin-Yoon Kim

Publications and source records attributed to Shin-Yoon Kim.

40 records · Page 3Linked to original sources

PubMed2002

Tendon-to-bone tunnel healing in a rabbit model: the effect of periosteum augmentation at the tendon-to-bone interface.

We examined whether periosteum enhances the healing process of a tendon in a bone tunnel and leads to better biomechanical fixation in a shorter period of time. The effect of the periosteum-wrapped tendon on tendon-to-bone healing was analyzed in 20 New Zealand white rabbits. The animals were divided into two groups, a periosteum-wrapped group and a control group. The two legs were operated on in the same manner. The long digital extensor tendon was harvested and transplanted into the proximal tibial tunnel. One limb was transplanted with the tendon wrapped with periosteum, while the other was without periosteum. The healed tendon-bone attachment was evaluated after 3 and 6 weeks by histological examination and biomechanical testing. At all time points histological examination demonstrated more extensive bone formation around the tendon with closer apposition of new bone to the tendon in the periosteum-wrapped limb than in the control limb. Biomechanical testing demonstrated higher tendon pullout strength in the periosteum-wrapped limb at all time points, with statistically significant differences between the periosteum-wrapped limb and the control limb after 3 and 6 weeks. Histological and biomechanical data suggest superior healing at the periosteum-wrapped side. These findings demonstrate that periosteum enhances the healing process when a tendon graft is transplanted into a bone tunnel.

Analysis of Variance↗

PubMed2002

Increased perfusion of the femoral head in transient bone marrow edema syndrome.

The pathophysiology of transient bone marrow edema syndrome is not known. Ischemia has been suggested as the pathophysiologic factor, because the histologic findings are similar to those of early stage osteonecrosis. Angiographic studies of osteonecrotic femoral heads have shown arterial interruption and impaired perfusion. The current report describes the angiographic and scintigraphic findings of transient bone marrow edema syndrome of the hip in a 45-year-old man. The nutrient arteries were dilated, and the femoral head perfusion was increased compared with the unaffected contralateral side. These findings suggest that a vasomotor response plays a role in the pathogenesis of transient bone marrow edema syndrome. The disease might be a reversible process after temporary ischemia of the femoral head.

Angiography↗

PubMed2002

Estrogen receptor alpha gene polymorphisms Pvu II and Xba I influence association between leptin receptor gene polymorphism (Gln223Arg) and bone mineral density in young men.

OBJECTIVE: The peak bone mass is recognized as an important determinant in the development of osteoporosis. We investigated associations between bone mineral density (BMD) and polymorphisms of the leptin receptor (LEPR) and estrogen receptor alpha (ERalpha) genes in young men. DESIGN: BMD, anthropometric characteristics, and serum leptin concentrations were measured in young men and compared with regard to the LEPR and ERalpha genotype. METHODS: From 219 healthy volunteers aged 20-34 Years, we genotyped the Lys109Arg, Gln223Arg, Ser492Thr, Ala976Asp, and Pro1019Pro variants of LEPR and the PvuII and XbaI variants of ERalpha using the polymerase chain reaction-restriction fragment length polymorphism method. We determined serum leptin concentrations by radioimmunoassay (RIA) and BMD by dual energy X-ray absorptiometry. RESULTS: The subjects carrying the Gln223 allele of LEPR had higher BMD at the lumbar spine compared with the subjects without this allele. There were no significant differences in BMD among PvuII and XbaI genotypes of ERalpha. However, an association between LEPR and BMD was noted in the subjects carrying the PP homozygotes of PvuII or the X alleles of XbaI, but this was not significant in those without these genotypes. CONCLUSIONS: This study indicates that the Gln223Arg polymorphism of LEPR is important for determination of the peak bone mass in men and that it is influenced by ERalpha gene polymorphisms.

Adult↗

PubMed2001

Mechanics of femoral head osteonecrosis using three-dimensional finite element method.

A three-dimensional finite element model of a femoral head was developed using a surface modeling technique. The distribution of the stress index S (S = effective stress / yield strength, sigma/sigmaY) in various sizes of segmental osteonecrosis was assessed. The stress index of the femoral head was within physiological limits when the necrotic angle was less than 110 degrees. Within both the subchondral region and the deep necrotic region adjacent to the necrotic-viable interface, values of the stress index significantly higher than the normal physiological level (>0.1) appeared when the necrotic angle was 110 degrees or more. In the analysis of 28 osteonecrotic femoral head specimens, fracture appeared in two major locations: the deep necrotic region near the underlying necrotic-viable interface (19 femoral heads) and the subchondral region (7 femoral heads). In 2 femoral heads, the fracture involved both regions. Both sites of fracture coincided with the region of stress index greater than 0.1 in the finite element model study. These results may provide baseline information for predicting the collapse of the femoral head and determining the treatment modality of early stage osteonecrosis.

Biomechanical Phenomena↗