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Biomedical subjects

Shinichi Yoshiya

Publications and source records attributed to Shinichi Yoshiya.

At least 91 records · Page 5Linked to original sources
PubMed2003

Solitary fibrous tumor in the extremity: case report and review of the literature.

A solitary fibrous tumor is a relatively unusual neoplasm first described as a distinctive tumor arising from pleura. Some reports have shown that solitary fibrous tumors also affect extrathoracic regions. The current study presents a literature review with four additional patients with solitary fibrous tumor arising from the extremities to clarify clinicopathologic features. The current four patients were two males and two females, ranging from 17 to 60 years of age. Magnetic resonance imaging scans of the current patients showed inhomogeneous low to intermediate intensity signal on T1-weighted images and inhomogeneous intermediate to high intensity signal on T2-weighted images. Histologically, the tumors were composed of a haphazard proliferation of spindle cells, although cellularity was variable in each case. Two of the four tumors showed hypercellularity of spindle cells with focally myxomatous or hyaline changes, whereas myxomatous patterns with scattered spindle cells throughout the specimens were observed in the other two tumors. Immunohistochemically, all four patients showed positive immunoreactivity for CD34, and two tumors showed focally positive immunoreactivity for bcl-2 protein. During the followup of 12 to 54 months, neither local recurrence nor distant metastasis was detected after wide resection. Examination of the literature and the current patients suggests that solitary fibrous tumors in the extremities are likely to have a malignant potential, although most patients have a benign clinical course. Local wide resection and careful long-term followup are necessary for patients with solitary fibrous tumor in the extremities.

Adolescent↗
PubMed2003

Cervical laminoplasty: evaluation of bone bonding of a high porosity hydroxyapatite spacer.

OBJECT: The purpose of this study was to evaluate the usefulness of a high-porosity hydroxyapatite (HA) spacer in cervical laminoplasty. Bone-spacer bonding rates, complications associated with the implant, and factors related to bone bonding were examined. METHODS: The authors evaluated 33 consecutive patients with cervical myelopathy who underwent high-porosity HA spacer-assisted laminoplasty and were followed for at least 1 year (mean 30 months). The results of bone-spacer bonding of the 147 implants were evaluated using computerized tomography (CT) scanning. The symptoms significantly improved in 30 patients. No difference in results was detected between patients with cervical spondylosis and those with ossification of posterior longitudinal ligament. Breakage of seven spacers occurred in four patients without causing neck pain or neurological deficits. There were no other HA spacer-related complications. The spacers became rigidly bound to bone in 61% of the cases, and bone regrowth developed around the spacer in 91%. The rate of bone-spacer bonding increased over time, and the CT-documented attenuation value (Hounsfield unit) of the spacer adjacent to the bone-spacer junction in the group in which union occurred was significantly higher than in the nonunion group. CONCLUSIONS: High-porosity HA spacer-augmented laminoplasty produced good bonding-related results. Bone bonding continued to progress 1 year after surgery, indicating the good osteoconductive capability of high-porosity HA. To avoid breakage of a spacer, a minimum 7-mm distance between spacers is necessary.

Biocompatible Materials↗
PubMed2003

Granulocyte colony-stimulating factor-producing undifferentiated sarcoma occurring in previously fractured femur. A case report and review of the literature.

We examined the case of a 52-year-old man presenting with a sarcoma accompanied by severe leukocytosis, which developed many years after a femoral fracture. Histologic, histochemical, immunohistochemical, and ultrastructural analysis of the tumor revealed that the sarcoma could not be classified by any of the bone or soft tissue tumor classifications currently in use. The tumor cells were isolated from surgical specimens and subcultured in vitro. The concentration of granulocyte colony-stimulating factor in the culture medium was constantly elevated to considerably high levels during 20 cell passages. A genomic study using reverse transcription-polymerase chain reaction showed that the cells retained messenger RNA expression of granulocyte colony-stimulating factor. The aberrant overexpression of granulocyte colony-stimulating factor clearly represented a paraneoplastic phenomenon of the neoplastic cells.

Cell Differentiation↗
PubMed2003

Cross-sectional area of a bone-patellar tendon-bone graft for anterior cruciate ligament reconstruction.

The cross-sectional area of the 10-mm wide patellar tendon graft was measured in 50 consecutive patients (31 males and 19 females) who underwent isolated anterior cruciate ligament (ACL) reconstruction and the relationship between the graft size and various factors such as physical characteristics was assessed. The effect of cross-sectional area of the implanted graft on postoperative stability of the reconstructed knee also was examined. Mean patient age at surgery was 22.3 years (range: 14-40 years). The cross-sectional area was measured using an instrumented area micrometer intraoperatively, and correlations between the measured value and various factors such as age, gender, height, body weight, and bony geometry were examined. Follow-up was performed 24 months postoperatively. The average cross-sectional graft area was 33.4 mm2. The measured cross-sectional area was larger in male patients and correlated with physical characteristics such as height, body weight, and femoral condyle width. No significant correlation between the size of the graft and postoperative stability was observed.

Adolescent↗
PubMed2003

Luxatio erecta (inferior dislocation of the shoulder): a report of 5 cases and a review of the literature.

Luxatio erecta (inferior dislocation of the glenohumeral joint) is an unusual type of shoulder dislocation. The authors present 5 new cases of luxatio erecta. All cases were hyperabduction injuries. In all cases, closed reduction was accomplished by a traction-countertraction maneuver. Three of the 5 subjects sustained concomitant fractures of the greater tuberosity. One underwent open reduction and internal fixation of the greater tuberosity. One suffered axillary nerve injuries. No vascular injuries were noted in our series. The mechanism of the injury is discussed.

Accidental Falls↗
PubMed2002

Pseudogout attack of the lumbar facet joint: a case report.

STUDY DESIGN: A case of acute low back pain caused by pseudogout attack of the lumbar facet joint is reported. OBJECTIVE: To report a new cause of acute low back pain previously unreported in the literature. SUMMARY OF BACKGROUND DATA: There have been some reports of lumbar spinal stenosis caused by calcium pyrophosphate dihydrate crystal deposition. However, there are no known reports of pseudogout attack of the lumbar facet joint. METHODS: An axial magnetic resonance imaging scan demonstrated joint effusion at the level of the bilateral L4-L5 facet joint. Aspiration of the left L4-L5 facet joint yielded 1.5 mL of pus-like synovial effusion. Multiple cultures of synovial fluid tested negative for bacteria and fungi, whereas compensated polarized light microscopy revealed monoclinic or triclinic crystals with a positive birefringence. RESULTS: The symptoms of acute low back pain lasted for 3 days. Local and systemic inflammatory signs, as well as symptoms, gradually improved after joint aspiration. A follow-up evaluation 8 months after lumbar facet joint aspiration showed complete resolution of pain and no neurologic deficit. CONCLUSIONS: Pseudogout attack of the lumbar facet joint is rare, but this clinical entity should be added to the differential diagnosis of acute low back pain.

Acute Disease↗
PubMed2002

Comparison of mechanical and histological properties between the immature and mature tendon attachment.

We tested the tensile strength of the Achilles tendon attachment to the calcaneus in skeletal mature and immature rabbits. The mean ultimate failure load was 179.6+/-28.6 N in the mature animals, and 138.5+/-36.1 N in the immature animals ( P<0.05). Although direct insertion was clearly observed histologically in the mature animals, direct insertion was not obvious in the immature animals. In the mature animals, failure occurred partly at the attachment zone (50%) and partly at the tendon zone (50%). In the immature animals, failure occurred at the attachment zone in 85% and at the tendon zone in 15%.

Achilles Tendon↗
PubMed2002

Neural fibrolipoma of the superficial peroneal nerve in the ankle: a case report with immunohistochemical analysis.

This report presents a case of neural fibrolipoma arising from the superficial peroneal nerve in the ankle. A 28-year-old woman was referred with a soft tissue mass in the anterior aspect of the right ankle, which had been gradually enlarging for the past 10 years. Magnetic resonance imaging showed a mass lesion, measuring approximately 8 x 3 x 2 cm, with high to partially low signal intensity on both T1- and T2-weighted images. A band of low signal intensity within the lesion, which is indicative of coexistence with the tumor and the superficial peroneal nerve, could be detected on both T1- and T2-weighted images. The patient underwent an excisional biopsy. The specimen microscopically consisted of nerve bundles and fibro-fatty proliferation with abundant collagen fibers. Immunoreactivity for CD34 antigen antibody was detected in fibrous spindle cells. This is the first report to present an immunohistochemical profile of neural fibrolipoma. Neural fibrolipoma should be considered as a differential diagnosis when a lipomatous lesion is encountered in the foot or ankle as well as in the upper extremities.

Adult↗
PubMed2002

Maximizing flexion after total knee arthroplasty: the need and the pitfalls.

Currently available knee prostheses can provide 100 degrees to 110 degrees of knee flexion, which is usually good enough for most daily activities, such as ascending or descending stairs and rising from chairs. Many activities require deep knee flexion, however. In Asian countries, deep knee flexion also is needed for special cultural activities. Preoperative range of motion, surgical technique, prosthesis design, and postoperative rehabilitation are important factors that influence postoperative range of motion.

Arthroplasty, Replacement, Knee↗
PubMed2002

Intracortical lipoma of the femur.

The authors report on a rare case of intracortical lipoma of the right femur in a 74-year-old woman. Magnetic resonance imaging and computed tomography of the femur demonstrated an intracortical lesion in the lateral diaphysis. No medullary involvement by the lesion was noted. Both imaging methods revealed the presence of fat in the lesion. Histologically, the tumor consisted of a large area of mature adipose tissues, admixed with foci of fat necrosis, calcification, and myxoid degeneration. Total excision of the tumor was curative. This is the second reported case of intracortical lipoma.

Aged↗
PubMed2002

Graft tension and knee stability after anterior cruciate ligament reconstruction.

This study examined the effect of the initial graft tension on the clinical outcome of anterior cruciate ligament reconstruction in a prospective randomized design. Fifty patients were enrolled in the study. In the reconstructive procedure, a bone-patellar tendon-bone graft was used. A set force of 25 N (5.6 lb) was applied in 25 patients and 50 N (11.2 lb) tension was maintained during fixation for the remaining 25 patients with the knee in full extension. In the immediate postoperative period, the anterior cruciate ligament reconstructed knee was similarly overconstrained in both groups. At 3 months, laxity of the surgically treated knee in both groups had increased significantly and become close to that of the contralateral knee. Measured laxity value showed a slight increase between 3 and 6 months, and remained similar thereafter. No significant difference in the clinical outcome was observed between the groups throughout the followup.

Adolescent↗
PubMed2002

Anterior spinal artery syndrome after total spondylectomy of T10, T11, and T12.

Although radical resection is the best treatment for local aggressive benign tumors or malignant tumors of the spine, total spondylectomy for lower thoracic vertebrae may cause anterior spinal artery syndrome. There are few reports in the literature in which this syndrome has been documented in association with thoracic spondylectomy, although this syndrome is the most common neurologic complication after abdominal aortic surgery. A 50-year-old woman with a giant cell tumor of the thoracic vertebrae was treated by posterior and anterior surgery. Thoracic segmental arteries from T10 to T12 had to be resected bilaterally to dissect the aorta free from the tumor. After resection of all feeding arteries to the tumor, the tumor and entire parts of T10, T11, and T12 were removed. Postoperative neurologic examination disclosed flaccid paralysis of the lower extremities and sphincter incontinence. Although pain and temperature sensation were absent, vibration and position sense were intact, showing anterior spinal artery syndrome. Intraoperative somatosensory-evoked potential monitoring only showed that transient deterioration failed to adequately reflect this neurologic injury. Major reconstructive surgery involving lower thoracic regions may cause anterior spinal artery syndrome. Somatosensory-evoked potential monitoring might not reliably predict overall neurologic outcome involving the blood supply of the lower thoracic regions.

Evoked Potentials, Somatosensory↗
PubMed2002

Lumbar multilevel degenerative spondylolisthesis: radiological evaluation and factors related to anterolisthesis and retrolisthesis.

Radiographs of 3,259 outpatients with low back disorders were examined for age, gender, level, direction, degree of slip, lumbar lordosis, pedicle-facet (P-F) angle, facet shape, and disc height. Degenerative lumbar spondylolisthesis was found in 284 (8.7%) of the patients, of which 83 were excluded. Single-level spondylolisthesis was present in 132 of the 201 patients studied, including 93 cases of anterolisthesis and 39 of retrolisthesis, the former being predominant at L4 and in women and the latter at L2 and equal between the genders. Multilevel spondylolisthesis in 69 patients included 65 (94%) of two-segment slip, 21 anterior, 25 posterior, and 19 combined, and 4 cases of three-segment retrolisthesis. Factors related to anterolisthesis were increased P-F angle and W-shaped facet joint; statistically, however, no factors were found statistically related to retrolisthesis. Multilevel anterolisthesis was considered to occur from factors similar to those previously reported for single-level anterolisthesis, and the pathomechanism of retrolisthesis is different from that of anterolisthesis.

Adult↗
PubMed2002

Repeat tears of repaired menisci after arthroscopic confirmation of healing.

We undertook 114 arthroscopic meniscal repairs in 111 patients and subsequently carried out second-look arthroscopy to confirm meniscal healing at a mean of 13 months after repair. Stable healing at the repaired site was seen in 90. Of these, however, 13 had another arthroscopy later for a further tear. The mean period between the repair and the observation of a repeat tear was 48 months. Of the 13 patients, 11 had returned to high activity levels (International Knee Documentation Committee level I or II) after the repair. An attempt should be made to preserve meniscal function by repairing tears, but even after arthroscopic confirmation of stable healing repaired menisci may tear again. The long-term rate of healing may not be as high as is currently reported. Second-look arthroscopy cannot predict late meniscal failure and may not be justified as a method of assessment for meniscal healing. Young patients engaged in arduous sporting activities should be reviewed regularly even after arthroscopic confirmation of healing.

Adolescent↗