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Biomedical subjects

K Y Tu

Publications and source records attributed to K Y Tu.

6 recordsLinked to original sources

Effects of discectomy on the stress distribution in the lumbar spine.

The change of the stress distribution of the lumbar spine after discectomy was analysed by the three-dimensional finite element method. It was shown that the stress level in the posterior element was higher, but that in the anterior element was lower than before disc excision. The most significant change of the stress distribution was found in the trabecular bone of the vertebral body. It is considered that in discectomy the normal disc tissue should be preserved as much as possible to maintain good function of the spine.

Biomechanical Phenomena

Lumbar intervertebral disc prosthesis. An experimental study.

To provide a more effective treatment and improve the outcome of surgical treatment of lumbar intervertebral disc protrusion, the values of lumbar intervertebral disc prosthesis (LIDP) were investigated. LIDP was specially designed and made of silicone rubber. The properties of material mechanics were investigated by compressive test and damage test of LIDP specimens. The biocompatibilities of LIDP were observed experimentally in monkeys. The surgical applicabilities were studied by in vitro experiments of fresh human lumbar spine. The results showed that LIDP has the advantages of good biomechanical applicability, biocompatibility and surgical applicability. LIDP is able to maintain the intervertebral space, stress balance and stability of the lumbar spine. after lumbar intervertebral disc excision, the replacement of LIDP could restore the functions of the lumbar spine and improve the curative results of disc excision.

Adult

Effect of partial discectomy on the stability of the lumbar spine. A study of kinematics.

The effect on the stability of the lumbar motion segment, as affected by partial discectomy, was investigated using three-dimensional motion measurement technique. Eight functional spinal units from fresh cadaver lumbar spines were potted and clinically relevant loads applied through a special loading frame attached rigidly to the top vertebra of the specimen. Partial discectomy was performed on the right side of the specimen. The three-dimensional motions of each lumbar motion segment, before and after partial discectomy, were recorded. The results showed that partial discectomy significantly affects the stability of lumbar spinal motion segments. The clinical relevance of this finding is discussed.

Adult

Treatment of longitudinal injuries in avascular area of meniscus in dogs by trephination.

A study promoting the healing of longitudinal injuries in an avascular area of the meniscus in 21 male dogs is reported. One horizontal hole from the peripheral vasculature to one of the artificial longitudinal injuries to both medial menisci of the knee in each dog was made with a needlelike trephine. The knee joints were not immobilized and the samples were taken 2, 4, 8, 12, and 24 weeks, respectively, after the operation. [3H]Thymidine was injected into the joint cavity 72 h before the sample was taken. Healed lengths were measured, and pathologic examinations and autoradiography were performed. The results showed that all of the injuries treated with trephination were partly or totally healed whereas those in controls were not healed at all, suggesting that trephination may be the procedure of choice for clinic orthopedists dealing with such injuries. By the 8th week, the healed length stopped increasing, the scar tissue began to mature, and the DNA synthesis of the fibroblasts in the granulation tissue and the fibrochondrocytes in the trephined meniscus reduced. It is thought that the fibrochondrocyte of the meniscus and the fibroblast in the granulation might be capable of obtaining the thymidine directly from the synovia of knee joint for their DNA metabolism. Multiplication of the fibrochondrocyte in the injured meniscus was also found.

Animals