Ensor E. Transfeldt

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The specific objective of this investigation was to assess and compare the relative performance of four types of pedicular fixation screws currently in use. All screws were tested under similar conditions. The results obtained have permitted the authors to rank the various screws tested in terms of performance as follows: 1) the Steffee screw, 2) the AO(More)
Long levels of spinal instrumentation and fusion are common in surgery for spinal deformity. The effect on the remaining mobile segments is not well understood. The changes in lumbar facet loading and lumbosacral motion were evaluated as the number of immobilized levels increased. Four fresh canine cadaveric spines from T6 to sacrum were used. Lumbosacral(More)
We reviewed two comparable groups of patients who had been treated for lumbar disc herniation by chymopapain chemonucleolysis (145) or conventional surgical discectomy (91). They were reviewed 10 years after treatment by questionnaire, followed by a personal interview by an independent observer. The results of the surgically treated groups were slightly(More)
Single level axial lumbar interbody fusion (AxiaLIF) using a transsacral rod through a paracoccygeal approach has been developed with promising early clinical results and biomechanical stability. Recently, the transsacral rod has been extended to perform a two-level fusion at both L4-L5 and L5-S1 levels (AxiaLIF II). No biomechanical studies have been(More)
STUDY DESIGN An in vitro biomechanical comparison of four posterior fixation techniques in the setting of an anterior lumbar interbody fusion (ALIF). OBJECTIVE To compare the initial stability, in terms of range of motion and neutral zone, provided by pedicle screws, facet screws, translaminar facet screws, and H-graft plus interspinous cables in the(More)
STUDY DESIGN An in vitro biomechanical comparison of 2 fusion techniques, anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF), on cadaveric human spines. OBJECTIVE To compare the immediate construct stability, in terms of range of motion (ROM) and neutral zone, of ALIF, including 2 separate approaches, and TLIF(More)
The aim of this study was to determine the optimal conditions, during general anesthesia, to obtain reproducible monitoring of compound muscle action potentials (CMAPs) as a means to evaluate motor tract integrity. The CMAPs were recorded in the soleus muscle of cats and were elicited by either single or double pulse stimulations (with various amplitudes(More)
STUDY DESIGN This study prospectively evaluated the health related quality of life (HRQOL) of 73 adults presenting with scoliosis at a single institution, as related to their spinal (C7 plumbline) and global (gravity line) balance. OBJECTIVE To assess the influence of sagittal and coronal balance on HRQOL in adult scoliosis. SUMMARY OF BACKGROUND DATA(More)
OBJECTIVE Herein, we report use of electromyography (EMG) to anticipate corticospinal conduction block, as defined by muscle-derived transcranial electrical motor evoked potential (TCE MEP) loss, during extradural spinal cord decompression. METHODS One hundred and eighty-four patients underwent cervical (173) or thoracic (11) decompression. The same(More)
Pedicle screws are placed using pilot holes. The trajectory of pilot holes can be verified by pedicle sounding or radiographs. However, a pilot hole alone does not insure that the screw will follow the pilot hole. No studies have characterized the risk of misalignment of a pedicle screw with respect to its pilot hole trajectory. The objective of this study(More)