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T Rogge

Publications and source records attributed to T Rogge.

8 recordsLinked to original sources
PubMed2000

Biomechanical studies of a dynamized anterior thoracolumbar implant.

STUDY DESIGN: An in vitro investigation into the biomechanical properties of a dynamized anterolateral compression implant that allows controlled subsidence. OBJECTIVES: To determine the extent to which both modes of the anterolateral compression implant (controlled collapsing and rigid) are able to reestablish the stability of the lumbar spine after L4 corpectomy. SUMMARY OF BACKGROUND DATA: Over time, anterior and posterior spinal implants have been associated with progressive angulation, and occasionally implant failure and breakage. To circumvent this occurrence and provide better graft loading, dynamized or collapsing devices for clinical use have been developed. METHODS: Eight fresh calf spines (L1-L6) were placed in a biomechanical testing frame. Pure moments of 6 Nm were loaded onto the intact spine in six directions: flexion, extension, right and left lateral bending, and right and left axial rotation. A total L4 corpectomy then was performed, and the defect grafted with a wooden dowel. Loading was repeated after the specimens were stabilized using the two modes of the anterolateral compression implant in succession. RESULTS: The results showed that both modes of the implant (the rigid mode in particular) restore the stiffness of the unstable spine to normal levels of flexion, extension, and right and left lateral bending, even to levels exceeding normal. These devices, however, fall short of achieving normal stability in right and left axial rotation. CONCLUSION: In the cadaveric calf spine after L4 corpectomy, restoration of stability with a dynamized anterior spinal implant is possible in flexion, extension, and right and left lateral bending, but not in axial rotation.

Animals↗
PubMed2000

Spinal stability with anterior or posterior ray threaded fusion cages.

OBJECT: The authors conducted a study to determine if the rigidity supplied to the spine by posterior placement of the Ray threaded fusion cage (TFC) is further enhanced by the placement of pedicle screws and, additionally, if bilateral anteriorly placed TFCs render the spine more rigid than a single anteriorly placed TFC. METHODS: Ten human cadaveric spinal specimens (L2-S1) were affixed within a testing frame. Loads of 1.5, 3, 4.5, and 6 Nm were applied to the spine in six degrees of freedom: flexion-extension, right and left lateral bending, and right and left axial rotation. Motion in an x, y, and z cartesian axis system was tracked using dual video cameras following light-emitting diodes attached to the spine and base plate. Load testing of the spines was performed in the intact mode, following which the spinal segments were randomized to receive anterior or posterior instrumentation. In five spine specimens we performed posterior discectomy, posterior lumbar interbody fusion (PLIF) with placement of femoral rings and pedicle screws, PLIF with bilateral TFCs, and bilateral TFCs with pedicle screws. Five other spines underwent anterior-approach discectomy, followed by implantation of a unilateral cage and bilateral cages. Load testing was performed after each step. CONCLUSION: Spines in which PLIF with pedicle screws and TFCs with pedicle screws were placed were more rigid than after discectomy in all directions of motion except flexion. Anterior discectomy provided significantly (p < or = 0.05) less stability in left and right axial rotation than the intact spines and following posterior discectomy. Following anterior implantation of bilateral TFCs, spines were significantly more rigid than after discectomy in all directions except extension.

Bone Screws↗
PubMed1999

Biomechanical studies on two anterior thoracolumbar implants in cadaveric spines.

STUDY DESIGN: A biomechanical comparison of two commonly used anterior spinal devices: the Smooth Rod Kaneda and the Synthes Anterior Thoracolumbar Spinal Plate. OBJECTIVES: To compare the stability imparted to the human cadaveric spine by the Smooth Rod Kaneda and Synthes Anterior Spinal Plate, and to assess how well these devices withstand fatigue and uni- and bilateral facetectomy. SUMMARY OF BACKGROUND DATA: Biomechanical studies on the aforementioned and similar devices have been performed using synthetic, porcine, calf, or dog spines. As of the time of this writing, studies comparing anterior spinal implants using human cadaveric spines are scarce. METHODS: An L1 corpectomy was performed on 19 spines. Stabilization was accomplished by an interbody wooden graft and the application of the Smooth Rod Kaneda in 10 spines and the Synthes Anterior Spinal Plate in the remaining 9. Biomechanical testing of the spines was performed in six degrees of freedom before and after stabilization, and after fatiguing to 5000 cycles of +/- 3 Nm of flexion and extension. Testing was repeated after uni- and bilateral facetectomy. RESULTS: After stabilization, the Smooth Rod Kaneda was significantly more rigid than the anterior thoracolumbar bar spinal plate in extension. After fatigue, the Smooth Rod Kaneda was significantly stiffer than the anterior thoracolumbar spinal plate in flexion, extension, right lateral bending, left lateral bending, and right axial rotation. A significant decrease in stiffness was noted with the Synthes device in flexion after bilateral facetectomy compared with the stabilized spine. CONCLUSIONS: The smooth Rod Kaneda device tends to be stiffer than the anterior thoracolumbar spinal plate, particularly in extension, exceeding the anterior thoracolumbar spinal plate in fatigue tolerance. The spine stabilized with the anterior thoracolumbar spinal plate is more susceptible to the destabilizing effect of bilateral facetectomy than than that stabilized with the Smooth Rod Kaneda. The additional rigidity encountered with the Smooth Rod Kaneda must be weighed against the simplicity of anterior thoracolumbar spinal plate application.

Aged↗
PubMed1977

[Granuloma multiforme].

A case of granuloma multiforme is reported. Granuloma multiforme has been seen so far only in blacks from Nigeria or East Africa. The disease does not affect children and adolescents. Common sites of infection are arms, chest, back, neck, and head. The differential diagnosis is tuberculoid leprosy and granuloma anulare. Granuloma multiforme also shows similarity to that of granuloma anulare or, if more of a tuberculoid nature, to that of sarcoidosis or that of granulomatosis disciformis chronica et progressiva Miescher. The etiology of granuloma multiforme is unknown. It may respond to intralesional corticosteroid therapy or show involution following a diagnostic biopsy. In the reported case response to intralesional corticosteroid suspension and topical application of dimethyldiphenylendisulfide was very satisfactory.

Adrenal Cortex Hormones↗