Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association
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To investigate recent trends in the incidence of fractures in children and adolescents, we conducted a survey of distal radius fractures in 1992 and 1995 in Tottori Prefecture, Japan. Seven-hundred and forty-five patients under age 20 years were registered (562 males and 183 females). The age and sex-specific incidences of fractures in patients under 20 years of age were higher in males than in females, showing peaks at age 12-13 years for males and at age 10-11 years for females. ⋯ The age and sex-specific incidences were compared with those in the period 1986-1988, which we reported previously. The incidence in each year showed a significant increase with time for males but not for females. We conclude that the incidence of distal radius fractures in children and adolescents has a prominent peak matched by the age of the growth spurt, and the incidence of the fracture has increased in males during the past decade in Tottori Prefecture.
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Abiomechanical study of the functions of the iliolumbar ligament in L5 spondylolysis was performed. Five fresh cadaveric specimens were used. The bilateral ilia and sacrum were fixed. ⋯ The three-dimensional position of the L5 vertebra was measured after serial transections in: (1) the intact condition; (2) bilateral pars interarticulares of L5 transected; (3) anterior bands of the iliolumbar ligaments transected; and (4) posterior bands of the iliolumbar ligaments transected. In L5 spondylolysis, flexion and axial rotation of L5 on S1 are significantly regulated by the anterior and posterior bands of the iliolumbar ligaments (especially by the posterior bands of the ligaments). The integrity of the ligament may determine the stability of the lumbosacral junction and the amount of forward slipping of the L5 vertebra.
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We used a commercially available computer-assisted navigation system (StealthStation; Sofamor Danek, Memphis, TN, USA) in both an in-vitro and a clinical study performed in 1996-1998. The basic data used for navigation were preoperative computed tomography (CT) scan imaging data. The position of the probe or drill guide was superimposed in real-time on a monitor. ⋯ All screws correctly passed through the pedicles. There were no neurological complications after surgery. Using this guided surgery system, we achieved satisfactory results both in the laboratory and in a clinical setting.
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Comparative Study
Neovascularization of the outermost area of herniated lumbar intervertebral discs.
In 64 surgically treated herniated lumbar intervertebral discs, we performed histopathological studies of neovascularization in the outermost layer of the herniated mass in various types of hernia. We obtained specimens separately from the capsule tissue covering the herniated mass and the inner tip tissue of the herniated mass for comparison. Histologically, in most cases, the capsule tissue was the outermost layer of the annulus fibrosus or posterior longitudinal ligament, and the inner tip tissue was the nucleus pulposus. ⋯ When the intervertebral disc herniates, new blood vessels proliferate in the capsule of the hernial tissue. At the stage when the hernial capsule tissue is still present, these vessels were observed to have difficulty reaching the inner tip portion. These findings suggest that when the nucleus pulposus portion of the herniated mass perforates the posterior longitudinal ligament, it may be subject to a stronger neovascularization reaction.
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Displaced fractures of the sacrum are often associated with mechanical instability and neurologic deficits that cause late musculoskeletal problems and pain. We describe the radiologic and neurologic characteristics of 12 displaced fractures of the sacrum, (in 5 men and 7 women; age at injury, 17-61 years) as well as the management and results. Seven patients had unilateral longitudinal fractures (ULF), and 5 had bilateral longitudinal fractures (BLF) with a transverse fracture. ⋯ Two patients did not recover neurologically; 1 patient with ULF had undergone late decompression for chronic radiculopathy and the other, with BLF, had had complete paralysis pre-operatively. Five patients with incomplete paralysis recovered both sensory and motor function. If a patient with a sacral fracture has instability, operative treatment with anatomical reduction is preferred.