Search PubMed⌕ Search

Biomedical subjects

Shinichi Yoshiya

Publications and source records attributed to Shinichi Yoshiya.

At least 73 records · Page 4Linked to original sources

Acute pyogenic sacroiliitis without predisposing conditions.

STUDY DESIGN: Clinical and imaging findings of patients diagnosed with pyogenic sacroiliitis were retrospectively analyzed. OBJECTIVES: To characterize the clinical and magnetic resonance features of patients with acute pyogenic sacroiliitis without the usually known predisposing conditions and to investigate the diagnostic value of magnetic resonance imaging in detecting the early stages of pyogenic sacroiliitis. SUMMARY OF BACKGROUND DATA: Pyogenic sacroiliitis is relatively uncommon, and accurate diagnosis is frequently delayed due to lack of awareness by clinicians and nonspecific clinical presentation. There have been few reports that have evaluated the clinical features of acute pyogenic sacroiliitis and investigated the diagnostic capabilities of magnetic resonance imaging in detecting pyogenic sacroiliitis in the early stages. METHODS: The clinical data of 9 patients (6 male, 3 female; average age 27.3 years) diagnosed with acute pyogenic infection of the sacroiliac joint were retrospectively analyzed. Magnetic resonance images as well as computed tomography of the sacroiliac joints were available in all cases. Seven of the patients underwent 99mtechnetium bone scans. RESULTS: All patients showed positive findings on magnetic resonance images, whereas 99mtechnetium bone scans were positive in six of seven patients. Eight patients responded well to treatment with intravenous antibiotic therapy, whereas one patient required debridement of the sacroiliac joint following conservative treatment. CONCLUSIONS: Both magnetic resonance imaging and technetium bone scanning are sensitive for localizing occult sites of bone inflammation. Magnetic resonance imaging may provide more useful information than bone scanning by screening for abnormalities in the sacroiliac joint region. With prompt appropriate antibiotic therapy, clinical improvement of patients can be expected.

Acute Disease↗

Total sacrectomy and reconstruction for sacral tumors.

STUDY DESIGN: Report of three patients in whom the lumbosacral junctions were successfully restored by spinal instrumentations after total sacrectomies. OBJECTIVES: To describe the surgical technique of the reconstruction of the continuity between the pelvic ring and spinal column by using a transpedicular and iliac screw system. SUMMARY OF BACKGROUND DATA: Although there have been case reports about reconstruction methods after total sacrectomy, biomechanical, and technical problems still remain unresolved. METHODS: Total sacrectomy was carried out in three cases: two with chordomas and one with a recurrent giant cell tumor. In the first case, reconstruction was achieved with Zielke transpedicular screw and rod system and a sacral rod. The other two patients were reconstructed using a transpedicular and iliac screw system and a sacral rod for bilateral fixation of the iliac wings. In the third patient, the vertical rods were connected to transverse rod with rod connectors. RESULTS: No instrumentation failure was observed, and the continuity between the pelvic wing and spinal column was established with the instrumentation and bone grafting. Although one patient died of metastatic chordoma, the lumbosacral junction was successfully reconstructed with the instrumentation. The other two patients could stand with double crutches 13 and 2 years after surgery, respectively. CONCLUSIONS: Total sacrectomy is a feasible operation for primary malignant tumors involving the entire sacrum. Reconstruction of the union between the lumbar spine and the ilia with spinal instrumentation achieves stabilization suitable for ambulation.

Adult↗

Symptomatic hematoma of lumbar facet joint: joint apoplexy of the spine?

STUDY DESIGN: A case report. OBJECTIVES: To report and discuss a rare case of epidural hematoma that was considered to be formed as a result of idiopathic bleeding occurring at the facet joint (joint apoplexy). SUMMARY OF THE BACKGROUND DATA: Spontaneous spinal epidural hematoma is a relatively rare condition. According to a review article of 199 spontaneous spinal epidural hematomas in the last 2 decades, the majority of these conditions are thought to result from a rupture of the epidural vascular network. Recently, a hemorrhagic lumbar synovial cyst and a hematoma occurring from the ligamentum flavum were reported as rare types of epidural hematoma. METHODS: The authors describe the treatment and the clinical, radiologic, surgical, and pathologic findings in one patient with a rare epidural hematoma. RESULTS: Magnetic resonance imaging revealed that the extradural mass lesion was continuous with the right L4-5 facet joint; this was confirmed by surgery when the extradural hematoma was directly visualized. The joint cavity was also filled with the hematoma. There was no evidence of preceding cyst formation macroscopically or microscopically. The excised capsule of the left L4-5 facet joint revealed moderate hyperplasia of the synovium with an increased number of capillary vessels. CONCLUSIONS: This is the first reported case of radiculopathy considered to be a result of facet joint apoplexy in the absence of any preceding synovial cyst formation. The pathomechanism of the hemorrhage at the lumbar facet joint is unclear, but it is speculated that there could be an association with degenerative change of the facet joint. Surgical excision of this mass was considered to be the definitive treatment.

Female↗

Septic arthritis of bilateral lumbar facet joints: report of a case with MRI findings in the early stage.

STUDY DESIGN: A case is reported. OBJECTIVE: To report and discuss a case of septic arthritis of bilateral lumbar facet joints with contiguous extension into the paraspinal musculature without infection of the vertebral body or disc space. SUMMARY OF BACKGROUND DATA: Septic arthritis of a lumbar facet joint is a rare cause of low back pain, and only a few cases have been described. If the condition is not associated with epidural or paraspinal abscess formation and self-limiting, the correct diagnosis may be overlooked. To the author's knowledge, septic arthritis of bilateral facet joints has not been previously described in the literature. METHODS: A 72-year-old woman without any systemic illness was hospitalized because of acute severe back pain and high fever. Examination showed local tenderness over the lower lumbar region. Magnetic resonance imaging showed widened facet joints, abscess in the joints, and paraspinal involvement, which aided diagnosis and preoperative planning. RESULTS: The infection did not respond to intravenous antibiotics therapy, so a thorough debridement of the bilateral facet joints was performed. At the latest follow-up assessment, the patient remained afebrile and had a marked reduction of low back pain. CONCLUSIONS: Septic arthritis of the lumbar facet joint is a rare cause of low back pain. It is important to ascertain the diagnosis at the earliest possible stage and to start intravenous antibiotics therapy as soon as possible. Magnetic resonance imaging is a quite sensitive method for identifying infection of the lumbar facet joint. Surgical debridement may be necessary if antibiotic therapy fails.

Aged↗

Multimodality imaging features of primary xanthoma of the calcaneus.

Secondary xanthomatous features are histologically observed in various bone lesions, but primary xanthoma of bone is rare. We present a primary xanthoma of the right calcaneus in a 51-year-old woman who had no aberrant lipid metabolism. Roentgenograms showed a small osteolytic lesion in the calcaneal triangle, partially surrounded by bone sclerosis. Computed tomographic scans of the calcaneus showed multiple osteolytic areas, with an irregular trabecular pattern in the surrounding sclerotic bone. T1-weighted magnetic resonance images showed a lesion with central low signal intensity, surrounded by a peripheral ring with high signal intensity. The entire lesion showed high signal intensity on T2-weighted images, partially surrounded by areas with low signal intensity, concordant with reactive bone sclerosis. Histologically, the lesion consisted of numerous lipid-laden histiocytes arranged in sheets, scattered multinucleated giant cells and lymphocytes, and granulation tissues. There was no evidence of pre-existing lesions. Total excision of the tumor was curative.

Bone Diseases↗

Unusual metastasis to the cauda equina from renal cell carcinoma.

STUDY DESIGN: This is a case report of a patient with renal cell carcinoma and intradural metastasis to the cauda equina. OBJECTIVE: To present a rare case of an intradural metastasis from renal cell carcinoma and to discuss the clinical features of metastatic tumors in the cauda equina and the possible mechanism of the tumor spread to the cauda equina. SUMMARY OF BACKGROUND DATA: Intradural spinal metastasis has been rarely reported in the English literature. Only two reports that describe the spread of metastatic renal cell carcinoma to the cauda equina have been published. METHODS: A 61-year-old man who underwent a nephrectomy for the treatment of renal cell carcinoma presented with worsening low back pain that radiated to both legs. Magnetic resonance imaging showed an ill-defined tumor mass in the cauda equina at L3. After a recapping T-saw laminoplasty of L3 was performed, the tumor was excised and the nerves involved in the tumor were transected. RESULTS: Pathologic examination showed papillary renal cell carcinoma with identical histology to the primary tumor. The patient's low back pain and radiating leg pain were relieved after operating. CONCLUSION: The majority of cauda equina tumors are primary tumors, and metastases are very rare. Intradural spinal metastasis pain is a characteristic cramping pain provoked by light percussion on the lumbar spine, becoming severe when sleeping in the flexion or sitting position. Magnetic resonance imaging is a useful tool for detecting intraspinal metastasis when the patient is complaining of a unique pain. A recapping T-saw laminoplasty to preserve posterior elements with tumor removal is feasible for relieving pain and demonstrating the pathology.

Carcinoma, Renal Cell↗

Horner's syndrome caused by a thoracic dumbbell-shaped schwannoma: sympathetic chain reconstruction after a one-stage removal of the tumor.

STUDY DESIGN: A case of Horner's syndrome caused by a thoracic dumbbell-shaped schwannoma is reported. OBJECTIVES: To report a rare case of a mediastinal dumbbell-shaped schwannoma as a cause of Horner's syndrome and to show the result of intercostal nerve grafting for sympathetic chain reconstruction after resection of the sympathetic nerve. SUMMARY OF BACKGROUND DATA: It has been reported that approximately 10% of neurogenic mediastinal tumors extend through the neural foramen into the spinal canal, creating a dumbbell shape. Although the most frequent causes of Horner's syndrome are tumors, a dumbbell-shaped schwannoma has rarely been described as a cause of the syndrome. Moreover, there have been no previous reports that primary sympathetic chain reconstruction has been performed with an intercostal nerve graft after resection of the sympathetic nerve with the tumor. METHODS: A 48-year-old woman was diagnosed with a mediastinal tumor by routine chest radiography. The patient had right-sided Horner's syndrome, the signs of which she had not noticed. Surgical resection of the dumbbell-shaped tumor was performed in a one-stage combined resection of both the intraspinal and the mediastinal component of the tumor. Primary sympathetic chain reconstruction was also performed with an intercostal nerve graft. RESULTS: The tumor was resected completely, and no recurrence of the tumor was observed 1 year after the operation. Blepharoptosis and anhidrosis on the right side of her face and upper limb gradually improved after surgery, and compensatory oversweating on the left side eventually improved. In bright illumination, the right pupil diameter was 3.5 mm and the left was 5 mm after surgery; the right pupil measured 4 mm and the left measured 5 mm 1 year after the operation. CONCLUSIONS: A mediastinal dumbbell-shaped schwannoma has rarely been described as a cause of Horner's syndrome. Primary sympathetic nerve reconstruction with an intercostal nerve was shown to be useful after resection of the sympathetic nerve involved in the tumor.

Female↗

Fine-needle aspiration biopsy of solid aneurysmal bone cyst in the humerus.

We report the fine-needle aspiration biopsy (FNAB) cytology findings of a solid aneurysmal bone cyst in the left humerus of a 69-yr-old woman. Radiographically, the lesion showed an extensive, relatively well-defined osteolysis in the diaphysis, with a pathologic fracture. FNAB smears of the lesion consisted of benign, mononuclear cells and numerous osteoclast-like multinucleated giant cells. Some clusters of the mononuclear cells were closely associated with dense, homogeneous, extracellular, matrix material. To our knowledge, the FNAB features of solid ABC of the long bones have not been described previously in the English-language literature. The cytologic features are indistinguishable from those of giant cell tumors of bone and brown tumors of hyperparathyroidism.

Aged↗

Analysis of the thickness and curvature of articular cartilage of the femoral condyle.

PURPOSE: To develop an optimal autologous osteochondral transplantation technique, we analyzed the thickness and curvature of the femoral condyle. TYPE OF STUDY: Basic research for surgical technique, anatomic study. METHODS: Eight cadaveric femoral condyles were sectioned sagittally into 8 slices. Photographs of each slice were digitized, and the thickness and curvature of the overlaying cartilage were analyzed using a National Institutes of Health image program. RESULTS: The average thickness of the cartilage was 1.69 mm. The minimum and maximum values were measured at 0.22 mm and 3.65 mm, respectively, with the thinnest part seen in the sulcus terminalis (the groove for meniscus). The average curvature of the cartilage was 4.4 m(-1). The minimum and maximum values were measured at -20.0 m(-1) and 27.2 m(-1), respectively. CONCLUSIONS: When the chondral lesion is assumed at the weight bearing area of the medial or lateral femoral condyle, the anterior portion of the sulcus terminalis (the groove for meniscus) in the middle section of the lateral condyle is considered to be the optimal donor site.

Aged↗

An intraligamentous ganglion cyst of the anterior cruciate ligament after a traumatic event.

An unusual case of intraligamentous ganglion cyst of the anterior cruciate ligament after a traumatic event in a 12-year-old boy is presented. Magnetic resonance imaging was helpful in delineating the lesion. An arthroscopic aspiration of the cyst material resulted in resolution of symptoms to preserve satisfactory knee function. The patient remains asymptomatic 25 months after surgery.

Accidental Falls↗

Extraabdominal desmoid tumor in a surgical scar of a patient with Sprengel's deformity.

Patients with an extraabdominal desmoid tumor have multiple minor bone abnormalities. The authors describe a rare case of an extraabdominal desmoid tumor that developed in a scar 2 years after surgery for Sprengel's deformity of the right shoulder in an 8-year-old girl. The association between the tumor and Sprengel's deformity has never been reported previously. Antecedent surgical trauma might play a role in the development of this tumor.

Back↗

Reconstruction of the iliofemoral ligament with an artificial ligament for recurrent anterior dislocation of total hip arthroplasty.

An 86-year-old woman underwent 4 revisions of hip arthroplasty and showed good position of both acetabular and femoral components. This was confirmed by roentgenographic measurements in the prone position. However, poor anterior acetabular covering after posterior inclination of the pelvis associated with lumbar kyphosis was observed in the standing position. Therefore, we reconstructed the iliofemoral ligament using a Leeds-Keio ligament to prevent anterior dislocation. At the 12-month follow-up evaluation, hip stability was confirmed, and the hip showed no further dislocation.

Aged↗

"Backside" polyethylene deformation in total knee arthroplasty.

The clinical importance of polyethylene deformation between the tibial insert and base plate ("backside") is unclear. We used a semiquantitative scoring system to compare clinical and radiographic factors with articular and backside deformation of 106 retrieved polyethylene tibial inserts. Backside deformation was associated with polyethylene thickness and type of locking mechanism. Deformation of the articular surface correlated with femoral osteolysis (P=.05). The mean backside deformation score was 33% greater for implants from patients with osteolysis than for implants from patients without osteolysis (P=.07). Our study may be biased based on the types of implants available for study, but for this group of implants, we cannot conclude with 95% certainty that backside polyethylene deformation was clinically important as a cause of periprosthetic osteolysis or implant loosening.

Adult↗

Solitary intra-articular tumoral calcinosis of the knee.

An unusual case of symptomatic, solitary, intra-articular tumoral calcinosis of the knee in a 39-year-old man is presented. This is the first reported case of intra-articular tumoral calcinosis with no associated underlying systemic diseases. Magnetic resonance imaging was helpful in delineating the lesion. Surgical excision resulted in resolution of symptoms and was not followed by recurrence of the lesion.

Adult↗

Isolated suprapatellar bursitis: Computed tomographic and arthroscopic findings.

A rare case of compartmentalized suprapatellar bursitis in the left knee of an 80-year-old man is presented. Computed tomographic (CT) scans following intravenous administration of contrast media showed a cystic mass between the quadriceps tendon and the anterior surface of the femur. Multiplanar reconstruction CT scans showed a mass superior to the patella, the wall of which was enhanced. Arthroscopic examination of the knee revealed a complete suprapatellar septum that separated the suprapatellar bursa from the knee joint cavity. Surgical excision of the bursa was curative. To our knowledge, multiplanar reconstruction CT and arthroscopic features of the isolated suprapatellar bursitis have not been illustrated previously.

Aged↗

Avulsion fracture of the posterior oblique ligament associated with acute tear of the medial collateral ligament.

The term posterior oblique ligament was proposed in 1973 but the specific anatomy of this region has been controversial. It has been concluded that the posterior oblique ligament is separated from the medial collateral ligament, each with distinctly different bony attachment points. In this article, we report a posterior oblique ligament avulsion fracture associated with a medial collateral ligament rupture.

Accidents, Traffic↗

Bone marrow edema syndrome associated with uterine myoma: a case report.

A patient with bone marrow edema syndrome of the hip associated with a uterine myoma is presented. A 51-year-old woman could not walk because of severe pain in both hips and had been referred to the authors' institute. Magnetic resonance imaging scans showed abnormal intensity on T1- and T2-weighted images in both femoral heads and a large mass arising from the uterus which was diagnosed as a uterine myoma. A 99mTc-methylene diphosphonate scintigraph showed diffuse uptake in both femoral heads. The pain in both hips decreased shortly after a hysterectomy and the patient could walk without crutches within 2 weeks after the gynecologic surgery. Magnetic resonance imaging scans taken 8 months after surgery showed high signal intensity on T1- and T2-weighted images, indicating normal bone marrow in the femoral heads. To the authors' knowledge, this is the first case report showing a bone marrow edema syndrome of the hip associated with uterine myoma. The pathophysiologic mechanisms for bone marrow edema syndrome of the hip in the current patient and in pregnancy may be identical. More specifically, a large intrapelvic mass may cause an increase of intrapelvic pressure and subsequent blood stasis in both conditions. The current case suggests the possible factors of bone marrow edema syndrome of the hip which need to be investigated.

Bone Marrow Diseases↗