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Biomedical subjects

E E Transfeldt

Publications and source records attributed to E E Transfeldt.

At least 37 records · Page 2Linked to original sources
PubMed1993

Ligaments of the lumbosacral spine and their role in possible extraforaminal spinal nerve entrapment and tethering.

The extraforaminal ligaments of the lumbosacral spine were studied in 34 cadavers. The corporotransverse ligament attached to the body and transverse process of the same vertebra. The ligament may entrap the exiting nerve root below it in rotary subluxation or in complete disk space loss. The lumbosacral ligament extends from the transverse process of L5 and the L5-S1 disk to the sacral ala, forming the roof of the lumbosacral tunnel through which the L5 spinal nerve passes. This may be the site of extraforaminal entrapment if lateral disk herniations, osteophytes, or tumor metastasis are also present. The nerve suspensory ligament attaches to the nerve sheath and to the disk and is felt to be significant as a vehicle for mechanoreception.

Genetic Variation↗
PubMed1993

Electrophysiologic evaluation of intermittent sacral nerve dysfunction in lumbar spinal canal stenosis.

Intermittent sacral nerve dysfunction, induced by walking in lumbar spinal canal stenosis, may cause symptoms including hyperesthesia and pain in perineum, urinary bladder incontinence, and penile erection. However, it is difficult to objectively document these symptoms. Evoked external urethral sphincter potentials by conus medullaris stimulation were measured both before walking and after walking in five patients who complained of sexual organ or urinary dysfunction during walking, and were compared with simultaneously induced sacral nerve symptoms. These potentials were also measured during surgery. Sacral nerve symptoms were reproduced by walking 80-350 meters (average 177.5 m). These potentials disappeared in one patient and were decreased in four patients at the time when the claudicant symptoms disabled the patient during walking. The amplitude subsequently recovered in keeping with relief of those symptoms during rest. Monitoring of these potentials during surgery showed an increase of amplitude shortly after the decompression procedure of the cauda equina. In conclusion, this measuring method was valuable as an objective evaluation of intermittent sacral nerve dysfunction in lumbar spinal canal stenosis.

Aged↗
PubMed1993

The effects of immobilization of long segments of the spine on the adjacent and distal facet force and lumbosacral motion.

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 motion was measured with an instrumented spatial linkage device, and facet loads were measured at L1, L4, and L7 using a strain gauge technique. Lumbosacral motion and facet loading were significantly increased (P < 0.05) after immobilization of proximal segments, and the amount of the increase was dependent on the number of immobilized segments (P < 0.05). This indicates that immobilization of long segments of the spine influences the remaining mobile segments by increasing the load and motion not only at the immediately adjacent segment but also at the distal segments.

Animals↗
PubMed1992

The effect of growth factor formula (platelet derived wound healing formula) in experimental spinal cord injuries.

The main purpose of this study was to investigate the usefulness of platelet derived wound healing formula (PDWHF) in the treatment of experimentally induced spinal cord injuries in cats. The injury model in ten adult cats consisted of the placement of three 22-gauge Teflon catheter sheaths into the spinal cord at the L2 level. Treatment consisted of coating these sheaths with PDWHF in Hydron. Three animals were used as controls. In the 7 remaining cats, treatment was double blinded. Cats were sacrificed at 3 weeks after injury and injured spinal cord segments were excised for histologic evaluation. Electrophysiologic and clinical motor function were evaluated throughout a period of observation. Evoked potentials in both the treated and control groups indicated incomplete spinal cord lesions due to insertion of the needles. There did not appear to be any significant improvement or difference in the evoked response and clinical function as a result of treatment with PDWHF. The histological findings in the PDWHF-treated group showed significant new vessel formation as well as dilation and around the injury site. This neovascularization, both qualitative and quantitative, was noted in the treatment group. This information, with a limited injury and very simple delivery system for growth factor, would suggest there is definite neovascularization occurring as a result of this treatment and this may be useful in the subsequent wound healing response such as axonal growth and scar tissue formation.

Animals↗
PubMed1992

Results of lumbar pseudarthrosis repair.

Forty patients underwent 47 procedures for repair of a lumbar pseudarthrosis at the University of Minnesota, Twin Cities Scoliosis Center between 1973 and 1986. Forty-three procedures in 36 patients with a minimum follow-up of 2 years were reviewed. Symptoms at the time of surgery included back pain (100%), leg pain (61%), subjective neurologic symptoms (49%), and thigh pain (35%). The diagnosis was made most commonly on the basis of pain radiographs (70%). In 38 cases, posterolateral fusion was performed, using segmental sublaminar wiring in 37%, a variable screw plate in 29%, Harrington compression rods in 16%, and no implant in 18%. Anterior interbody fusion was performed in six cases, including one combined fusion. Follow-up averaged 4.4 years. Solid fusion was achieved in 49% of cases. Eighty-six percent of patients continued to have low-back pain. Clinical outcomes were graded as excellent in 7%, good in 35%, fair in 9%, and failure in 49%. Significantly improved results were seen in patients in whom a solid fusion was obtained (p less than 0.005), in patients who had undergone only one prior surgery on the lumbar spine (p less than 0.01), and in patients in whom the initial fusion had been performed for spondylolisthesis rather than a primarily degenerative disorder (p less than 0.025). A trend toward better results was seen in cases in which the patient did not complain of leg pain preoperatively, in which a Workers' Compensation claim was not involved, and in which a prior attempt at pseudarthrosis repair had not been performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Changes in vertebral rotation after Harrington and Luque instrumentation for idiopathic scoliosis.

This study was carried out to analyze the three-dimensional and in particular the rotational correction obtained after spine instrumentation for idiopathic scoliosis. Preoperative and postoperative radiographs and computed tomographic scans with single axial cuts through each vertebral level were obtained for 14 patients: 4 Harrington, 7 Luque, and 3 Harrington-Luque. Rotation of vertebrae relative to the spinal axis and rotation between vertebrae (segmental rotation) were measured from computed tomographic scans of instrumented and uninstrumented segments. The derotation and changes occurring after surgery were calculated. Before operation, rotation was maximal at the apex, and close to 0 at the end vertebra; segmental rotation was greatest at the end of the curve, and minimal at the apex. After Harrington instrumentation the apical vertebrae showed a median derotation of 16%, after Luque instrumentation it was 12% and after Harrington-Luque instrumentation it was 13%. Segmental derotation did not uniformly occur. Major derotation was obtained at the end vertebrae and 39% of the total derotation occurred outside of the instrumented levels of the spine.

Adult↗
PubMed1991

Surgical treatment of neuropathic spinal arthropathy.

Surgical treatment of neuropathic spinal arthropathy is traditionally associated with a high rate of complication. Ten patients were treated surgically using contemporary techniques of spinal instrumentation and fusion which included combined anterior and posterior procedures when appropriate. The etiology of the spinal arthropathy was fracture (8 patients) and tumor (2 patients). Mean postsurgical follow-up was 4 years. Solid arthrodesis was obtained in eight patients. Our recommendations for surgical treatment include (a) posterior segmental instrumentation and fusion for single level Charcot involvement, with bone grafting of the anterior single level defect accomplished through the posterolateral approach; (b) restoration of normal sagittal plane contour, with anterior first stage surgery recommended for rigid kyphosis or multiple level Charcot involvement; and (c) leaving no intercurrent unfused segments between new and old fusions in the area of neurologic deficit. Fusion to the pelvis is not always necessary but late arthropathy may develop between the fused segment and the pelvis.

Adult↗
PubMed1991

Chymopapain versus conventional surgery for lumbar disc herniation. 10-year results of treatment.

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 better than those treated with chymopapain. In particular, there was significantly better early relief of leg and low back pain, and fewer patients needed a second procedure. Complications were few in both groups.

Activities of Daily Living↗
PubMed1991

Rotational changes of the vertebral-pelvic axis following Cotrel-Dubousset instrumentation.

Ten consecutive patients with adolescent idiopathic scoliosis and King-Moe curve Types II and III, scheduled consecutively for Cotrel-Dubousset instrumentation, underwent pre- and postoperative computed tomography scans with axial slices through each vertebra, and including the pelvis. Vertebral rotation was measured and referenced to the pelvis. Average derotation of the thoracic apex after surgery was 9%. King-Moe Type II curves tended to derotate more successfully (average 26% improvement), while Type III curves derotated very little, if at all (average 1.3% worsening of the rotational deformity). Type II curves often showed segmental rotational changes outside the levels of instrumentation, while Type III curves did not; more frequently the spinal-pelvic axis rotated en bloc. It appears, therefore, that Cotrel-Dubousset instrumentation does not consistently or predictably derotate the thoracic apex relative to the pelvis, and coronal plane correction may only be apparent, due to transmitted torque and rotation of the entire spinal-pelvic axis.

Adolescent↗
PubMed1991

Treatment of adult spinal deformity with fusion to the sacrum using CD instrumentation.

The effectiveness of Cotrel-Dubousset (CD) instrumentation in long fusions to the sacrum for adult spinal deformity was evaluated in 27 consecutive patients. The CD system provided acceptable correction of kyphosis and scoliosis while restoring or maintaining lumbar lordosis. However, the standard CD pelvic fixation using sacral pedicle and alar screws was problematic. Instrumentation-related complications were frequent (70%). Sagittal and frontal plane balance was difficult to achieve and not consistently maintained. The CD system using sacral pedicle and alar screws in the adult patient does not appear to offer advantages over alternative techniques for achieving arthrodesis to the sacrum for adult deformity.

Adult↗
PubMed1991

Management of pseudarthrosis after arthrodesis of the spine for idiopathic scoliosis.

Sixty-three first, second, or third-time repairs of one or more pseudarthroses were done in fifty-one patients who had had an arthrodesis for idiopathic scoliosis. Forty-five of the patients were female and six were male. The average age was 30.2 years. The indications for the sixty-three repairs were pain (twenty-five repairs), progression of the curve (sixteen), both pain and progression of the curve (twelve), and radiographic changes only (ten). Failure of the implant was identified before 27 per cent of the sixty-three procedures. The pseudarthroses were diagnosed an average of 2.8 years after the initial arthrodeses. Sixty-eight per cent of the defects were visible on plain radiographs preoperatively and 32 per cent were identified at operation. During the time between the original arthrodeses and the repairs of the pseudarthroses, the scolioses increased by a mean of 7 degrees and the kyphoses, by a mean of 10 degrees. Harrington distraction was the most commonly used instrumentation (twenty-six [41 per cent] of the sixty-three procedures), and autogenous iliac bone was the most commonly used material for the graft (thirty-three [52 per cent] of the procedures).

Adolescent↗
PubMed1990

Spinal sensory and motor tract activation after epidural electrical stimulation in the cat.

Somatosensory evoked potentials (SEPs) after peripheral nerve stimulation and motor evoked potentials (MEPs) after transcranial stimulation have been routinely used as monitors of the viability of pathways in the posterior and anterior spinal cord, respectively, in patients undergoing spinal cord surgery. To assess total spinal cord function, both of these procedures must be performed simultaneously, which is both cumbersome and technically difficult. The objectives of this study were to demonstrate both sensory and motor spinal tract activation after epidural electrical stimulation of the cat spinal cord. Thirty-seven adult mongrel cats were anesthetized with ketamine, intubated, and maintained with Ethrane and nitrous oxide. Stimulating electrodes were placed over the right dorsolateral spinal cord epidurally at T7 after a laminectomy. Recording electrodes were placed over the right L3 spinal cord epidurally, on the right L7 dorsal and ventral nerve roots, on the right and left sciatic nerves in the popliteal fossa, and in the right gastrocnemius muscle. After epidural stimulation of the spinal cord at T11, distinct reproducible potentials were recorded at each site. Activity in the L7 dorsal root implicated activation of spinal sensory tracts. Activity in the L7 ventral root and in the gastrocnemius implicated activation of spinal motoneurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Decompensation after Cotrel-Dubousset instrumentation of idiopathic scoliosis.

Spinal decompensation after corrective surgery for scoliosis appears to be a significant problem after Cotrel-Dubousset instrumentation (CDI). CDI produces torsional changes in the instrumented and uninstrumented spine that could result in spinal imbalance. Preoperative and postoperative three-dimensional analysis including computed tomography (CT) scans to measure vertebral rotation and segmental rotation were performed to evaluate the importance of torsional changes. Moe/King Type II deformities had a substantially greater risk of imbalance. Deformities instrumented over fewer spinal segments were less likely to decompensate. Specifically, instrumentation excluding the mobile transition segment, determined by maximum segmental rotation and segmental Cobb angle, was likely to decompensate. Derotation and deformity correction excessive in relation to preoperative side bending flexibility and segmental rotation frequently resulted in imbalance. Spinal imbalance after CDI can be reduced by avoiding overcorrection and inclusion of mobile transition segments.

Adolescent↗
PubMed1990

Delayed anterior decompression in patients with spinal cord and cauda equina injuries of the thoracolumbar spine.

Forty-nine patients with complete and incomplete injuries of the spinal cord or cauda equina who had undergone anterior decompression at a minimum of 3 months after injury were examined. Follow-up was from 12 months to 19 years. Postoperative neurologic improvement occurred in 46.5% of patients with incomplete injuries. If the surgery was performed less than 2 years after injury, neurologic improvement occurred in 68% with an improvement in Frankel grade of 32%. Bladder function improved in 27% of patients and if operated on less than 2 years after injury improvement occurred in 43%. Conus medullaris decompression resulted in a 50% improvement. There was an 83% improvement in the pattern of pain after decompression. Of 23 patients with preoperative spasticity, 10 improved but 6 were worse after surgery.

Adult↗
PubMed1989

Multiple-level noncontiguous spinal fractures.

Double-level noncontiguous spinal injury is a more common occurrence than generally appreciated. A large number of these patients have neurological injury. Because these injuries occur in patients who meet the criteria for categorization as multiple trauma patients, we feel that a complete radiographic survey of the spine must be accomplished in the emergency room in any situation where clinical assessment is impaired. Treatment must be individualized with the same guidelines for treatment as for the isolated injury in the majority of circumstances.

Adolescent↗
PubMed1987

Radiocarpal osteoarthritis associated with bilateral bipartite carpal scaphoid bones: a case report.

Bipartite carpal scaphoid is a rare congenital anomaly. The authors report on a 56-year-old man who presented with bilateral wrist pain without a history of trauma. X-ray films demonstrated bilateral symmetric bipartition of the scaphoid into a large distal ossicle and a smaller proximal ossicle. There was degenerative change in the articulation between the distal ossicle and the radial styloid. The joint space between the proximal ossicle and the scaphoid fossa was preserved. The absence of periscaphoid degenerative change has been suggested as a criterion for the diagnosis of congenital bipartite scaphoid. This patient fulfilled all other criteria for the diagnosis and the authors suggest that degenerative change developed due to abnormally high contact force between the distal ossicle and the radial styloid. An identical pattern of degenerative change has been observed in long-standing nonunion of the scaphoid, likely due to a similar mechanism. Radiocarpal osteoarthritis can develop in patients with congenital bipartition of the scaphoid and is similar to that observed in long-standing nonunion of the scaphoid.

Carpal Bones↗
PubMed1980

The effect of spinal distraction on regional spinal cord blood flow in cats.

Distraction is considered to be a factor in many spinal cord injuries. With a specially designed distraction apparatus and the 14C-antipyrine autoradiographic technique, the effect of distraction on spinal cord blood flow (SCBF) in cats was studied. Distraction was performed at L2-3 at a rate of 0.25 cm/10 min, and the spinal evoked response (SER) was monitored by stimulating the sciatic nerve and recording at T-13. The SCBF was assessed in five control animals, four animals in whom the SER was markedly altered by distraction, and five animals after the SER had been abolished and an additional 0.5 cm distraction applied. Control cats had gray- and white-matter flows of 44.5 +/- 1.4 (SEM) and 10.5 +/- 0.4 ml/100 gm/min, respectively. Distraction to the point of marked SER alteration caused a 50% loss of SCBF at and caudal to the distraction site. An additional 0.5 cm distraction produced total abolition of SCBF at the distraction site and for a considerable distance rostral and caudal to it. Thus, it is shown that spinal distraction causes cord ischemia similar to that seen with other types of spinal cord injury. In addition, distraction severe enough to cause loss of the SER has already produced severe cord ischemia.

Animals↗