Kiyoshi Kaneda — Page 2

PubMed2002

Simultaneous strain measurement with determination of a zero strain reference for the medial and lateral ligaments of the ankle.

The strain changes of the central part of the anterior talofibular ligament (ATFL), the posterior talofibular ligament (PTFL), the calcaneofibular ligament (CFL), and the tibiocalcaneal ligament (TCL) were measured simultaneously for a full range of ankle motion. Twelve fresh frozen amputated ankles were used. To measure the strain changes of the ligaments, a Galium-Indium-filled silastic strain transducer was implanted in the center of each ligament. The zero strain reference was determined immediately after the measurement of strain changes in five of the 12 ankles by tensile testing of each bone-ligament-bone preparation. The maximum strain change of the ATFL, the PTFL, the CFL and the TFL were 7.9%, 5.9%, 5.3% and 5.2%, respectively. The ATFL was elongated in plantar flexion and shortened in dorsiflexion. The PTFL and the CFL were shortened in plantar flexion and elongated in dorsiflexion. The TCL was the longest around the neutral position and became shorter in planter flexion and dorsiflexion. The results showed that the ATFL was taut in plantar flexion over 16.2 degrees, the PTFL and the CFL were taut in dorsiflexion over 18 degrees and 17.8 degrees respectively, and the TCL was taut between 9.5 degrees of dorsiflexion and 9.5 degrees of plantar flexion. The length change pattern was different among the ankle ligaments, although there was only a slight difference between that of the PTFL and the CFL. This study provides fundamental data useful in studying ankle ligament reconstruction.

Adolescent↗

PubMedDate not supplied

Effects of aging and spinal degeneration on mechanical properties of lumbar supraspinous and interspinous ligaments.

BACKGROUND CONTEXT: The effects of aging and spinal degeneration on the mechanical properties of spinal ligaments are still unknown, although there have been several studies demonstrating those of normal spinal ligaments. PURPOSE: To investigate the mechanical properties of the human posterior spinal ligaments in human lumbar spine, and their relation to age and spinal degeneration parameters. STUDY DESIGN/SETTING: Destructive uniaxial tensile tests were performed on the human supraspinous and interspinous ligaments at L4-5 level. Their mechanical properties were compared with age and spinal degeneration using several imaging modalities. PATIENT SAMPLE: Twenty-four patients with lumbar degenerative diseases on whom posterior surgeries were performed, with the age ranging from 18 to 85 years. OUTCOME MEASURES: The ultimate load and elastic stiffness as structural properties, the degree of disc degeneration, range of segmental motion, the disc height, disc space narrowing ratio and degree of facet degeneration as the parameters of spinal degeneration. METHODS: Twenty-four supraspinous and interspinous ligaments at the L4-5 level were obtained from posterior surgeries of patients with lumbar degenerative disease. The mechanical tests of bone-ligament-bone complexes were performed in a uniaxial tensile fashion with a specially designed clamp device. The ultimate load and elastic stiffness were calculated as structural properties. The degree of disc degeneration, range of segmental motion, the disc height, disc space narrowing ratio and degree of facet degeneration were examined by using radiographs, computed tomography and magnetic resonance imaging. RESULTS: The average and SD value of ultimate load, elastic stiffness, tensile strength and elastic modulus were 203+/-102.9 N, 60.6+/-36.7 N/mm, 1.2+/-0.6 Mpa and 3.3+/-2.1 Mpa, respectively. A significant negative correlation was found between age and tensile strength (p= 0.02). The specimens with facet degeneration showed lower values in tensile strength and elastic modulus than those without facet degeneration (p<0.04). However, no correlation was found between disc-related parameters and tensile strength. CONCLUSIONS: The mechanical strength of human lumbar posterior spinal ligaments decreases with age and facet degeneration, particularly in the ligament substance.

Adolescent↗