Biomedical subjects

P L Clothiaux

Publications and source records attributed to P L Clothiaux.

3 recordsLinked to original sources

PubMed1993

Cervical injuries under flexion and compression loading.

Cervical spine segmental tests were performed to determine the specific patterns of initial cervical injury in response to loading just beyond the point of structural failure. Well-defined combinations of flexion rotation and compression translation were applied to segments with varying degrees of disc and facet degeneration. Twelve cervical spine specimens (from human cadavers ages 52-91 years), each consisting of three vertebrae (two motion segments) from the middle (C2-C5) or lower (C5-T1) regions, were subjected to pure flexion rotation (seven specimens) or to combined flexion rotation and axial compression translation (five specimens). Specimens were sectioned and dissected to determine the patterns of structural failure. Pure flexion, and combined flexion and compression produced similar patterns of injuries. The disc was the most commonly injured structure, with annular injuries noted in 8 of the 12 specimens, and with anterior herniation of the nucleus occurring in two specimens. Wedge fractures and posterior ligament injuries were noted in both specimen groups and with both modes of loading. We conclude that similar patterns of initial anterior bony compressive failure and posterior ligamentous failure can occur with both flexion and with combined flexion-compression, without axial or lateral rotation, at low rates of loading. Anterior cervical disc herniations were produced in both middle and lower cervical segments.

Aged↗

PubMed1992

Posterolateral lumbar and lumbosacral fusion with and without pedicle screw internal fixation.

Forty-seven patients who had lumbar or lumbosacral fusion with or without pedicle screw internal fixation by one surgeon for treatment of degenerative lumbar disease with clinical instability were retrospectively reviewed by an independent observer. Eighteen of the 21 patients whose fusions were internally fixed with the Variable Spinal Plating (VSP) system were available for review. A control group consisted of 27 patients who had fusion without internal fixation. The rate of pseudarthrosis did not significantly differ between the two groups (VSP group, 22%; versus control group, 26%). Twelve (67%) of the 18 patients treated with fusion and VSP instrumentation were considered to have had a good or excellent outcome, whereas 19 (70%) of the 27 patients treated by fusion without internal fixation had good or excellent results. Two VSP-instrumented patients had postoperative leg dysesthesias, whereas this complication was not observed in the control group. Bilateral posterolateral lumbar or lumbosacral fusion without internal fixation is as effective as and safer than fusion with pedicle screw instrumentation.

Adult↗

PubMed1991

Three-dimensional load displacement properties of posterior lumbar fixation.

Pedicular fixation devices for the posterior treatment of segmental spinal instability are thought to offer enhanced stabilization compared with sublaminar wire systems, while avoiding the immobilization of multiple normal motion segments. We compared the performance of three dissimilar stabilization systems: the Hartshill rectangle, the Acromed/Steffee interpedicular screw and plate, and the Synthes/Dick fixateur interne. Human cadaveric lumbosacral specimens were first tested intact, then after a laminectomy and a facetectomy at the L3/L4 level, and finally after the fixation devices were sequentially attached. Constructs spanning two to four vertebral levels were compared for stabilization of the resected lumbar spine segments. When tested in compression, the Acromed/Steffee system with pedicular screws at L2-L5 allowed significantly less intersegmental distraction than the Synthes/Dick construct with screws at L2 and L5 only, and less than the intact and the destabilized uninstrumented spine. When sagittally rotated, the Acromed/Steffee construct with screws at L2-L5, or at L2 and L5, allowed significantly less distraction than the intact or destabilized segments, and the construct with screws at L2 through L5 allowed less distraction than the Synthes/Dick constructs with screws at L3/L4 or L2/L5. With the exception of the Acromed/Steffee system with screws at four levels, there were no significant differences in distraction allowed between the Synthes/Dick and Acromed/Steffee constructs, or between the multisegment and single segment constructs. There were no significant differences in stiffness across levels L3/L4 with the various implants. Results indicate that the use of posterior spine constructs significantly augment the stability of posterior segmental defects. Pedicular fixation immediately cephalad and caudad to the defect provided stable fixation in this application.

Bone Plates↗