Chiaki Hamanishi

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The objective of the current study was to identify a new extraarticular anatomic landmark indicating the anteroposterior orientation of the tibia using computed tomography. In 39 volunteers (20 males, 19 females), computed tomography scans for healthy right knees in extension were done perpendicular to the tibial shaft axis. The anteroposterior axis of the(More)
Anatomic reference axes that determine rotational alignment of the tibial component have not been established. To assess variability of three anatomic reference axes (a new tibial anteroposterior axis that we proposed, the transmalleolar axis of the ankle, and the second metatarsus bone axis of the foot), we measured the angles between a defined(More)
The cross-sectional area of the lumbar dural tube was calculated from transverse-slice lumbosacral magnetic resonance images (MRI) using the simple geometric formulas and computerized digitizer in 51 patients with low-back pain only, 79 with mainly radicular symptoms, and 53 with intermittent claudication, and in 39 controls with confirmed symptomatic(More)
Sixty-nine cases of congenital vertical talus (CVT) were classified into five groups in association with (1) neural tube defects or spinal anomalies, (2) neuromuscular disorders, (3) malformation syndromes, (4) chromosomal aberrations, and (5) idiopathic CVT unassociated with any of the systemic conditions described above. Forty-four cases of idiopathic CVT(More)
One hundred and eight neonates and infants who showed the clinical triad of a head turned to one side, adduction contracture of the hip joint on the occipital side of the turned head, and truncal curvature, which we named TAC syndrome, were studied. These cases included seven with congenital and five with late infantile dislocations of the hip joint and 14(More)
OBJECTIVES Osteoarthritis (OA) is a common joint deterioration initiated by multiple factors. To better understand related factors in the development of this disease, we focused on the mechanical stress loaded on articular cartilage. MATERIALS AND METHODS The anterior cruciate ligaments of rabbit knee joints were transected, and expression of protein(More)
OBJECTIVE We have previously demonstrated that reactive oxygen species (ROS) are involved in cartilage degradation. Decreased size of hyaluronan (HA), the major macromolecule in synovial fluid, to which it imparts viscosity, is reported in patients with arthritis. The purpose of this study was to determine the alteration in the molecular weight range of HA(More)
A total number of 442 dorsal root ganglia (DRG) in the lumbosacral region of 104 patients were depicted from the axial views of MRI and their localities were classified as intraspinal, intraforaminal, or extraforaminal types. The DRG of the more distal nerve root were located more medially. Asymmetrical locations were observed in 25 pairs of DRG among 221,(More)
Abnormal mechanical stress loaded on the cartilage leads to the osteoarthritis (OA). Although intraarticular hyaluronan (HA) injection is an effective treatment for OA, the underlying mechanism has not been made clear. Mechanical compression was loaded on the bovine cartilage using the Biopress system. Proteoglycan (PG) and reactive oxygen species (ROS)(More)
Schmorl's nodes were observed in 76 (19%) of 400 patients with lumbar symptoms, and in 10 (9.4%) of 106 control patients. In the lumbar group, the highest incidence was 57%, in the second decade of life, and the lowest was 5%, in the sixth decade of life. Using MRI, among both groups, a total number of 218 Schmorl's nodes were observed at 170 disc levels;(More)