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Biomedical subjects

L L Wiltse

Publications and source records attributed to L L Wiltse.

At least 37 records · Page 2Linked to original sources
PubMed1986

A biomechanical study of intrapeduncular screw fixation in the lumbosacral spine.

This laboratory experiment was undertaken to identify factors contributing to intrapeduncular screw fixation in the vertebra. Testing was performed in axial pull-out and cyclic loading modes using multiple screw designs inserted to various depths into fresh human lumbosacral vertebra. The degree of osteoporosis played a major role in pull-out strength. Larger diameter, full-threaded screws inserted deep enough to engage the anterior vertebral cortex resulted in the most secure fixation. In the sacrum, the second sacral pedicle was the weakest location of insertion. Screws aimed laterally into the ala at 45 degrees or medially into the first sacral pedicle resisted larger axial pull-out loads than those inserted straight anteriorly into the ala. Methyl methacrylate was found to restore secure fixation in previously-loosened screws and pressurization of cement doubled the pull-out force. In cyclic load tests, deeper-inserted screws were found to withstand a greater number of cycles before loosening. Measurements of pedicle outer cortical diameters were found in many specimens to be smaller than both the 4.5-mm and 6.5-mm diameter screws.

Aged↗
PubMed1985

Treatment of degenerative spondylolisthesis.

The purpose of this article is to evaluate three surgical approaches to the treatment of degenerative spondylolisthesis. A review of 107 surgically treated cases were used to select a group of patients who met the following criteria: No previous spine surgery, no involvement in litigation, and no significant lesions at other levels of the spine. Adequate follow-up. The selected group of 47 surgically treated cases of degenerative spondylolisthesis had follow-up of 2-7 years. Three surgical approaches to the treatment of degenerative spondylolisthesis were analyzed. A relatively small patient group with a wide posterior decompression, at the level of the slip, sacrificing the articular processes had good to excellent results in only 33% of the cases. A second group with a midline posterior decompression with preservation of the articular processes had 80% good to excellent results after 2 years. The third group with a midline decompression and preservation of the articular processes had an added intertransverse process fusion between the olisthetic levels. This group had 90% good to excellent results. The conclusion is that a posterior decompression with preservation of the articular processes plus a transverse process fusion at the involved level is the preferred method of treatment for degenerative spondylolisthesis without regard to age.

Aged↗
PubMed1983

Safety and efficacy of chymopapain (Chymodiactin) in herniated nucleus pulposus with sciatica. Results of a randomized, double-blind study.

A double-blind, randomized trial was conducted to compare the efficacy of intradiskal injection of chymopapain (Chymodiactin) with injection of placebo in patients with a herniated lumbar disk. Patients were randomly assigned to either placebo or drug regimens and followed up for six months. The primary measure of performance was agreement by patient and surgeon that further intervention was not necessary. At any time that patient and investigator agreed that treatment had failed, the patient was classified as a failure and the treatment code was broken. Of 53 placebo-treated patients, 31 failed by this criterion. Of 55 drug-treated patients, 15 failed. Placebo-treated patients who failed were allowed to receive drug treatment, and 29 (91%) of 32 were treated successfully. This study demonstrates that chymopapain is more effective than placebo for treatment of patients with a herniated lumbar disk.

Adult↗
PubMed1983

Chemonucleolysis in the treatment of lumbar disc disease.

In a follow-up study of a large group of patients who had been treated by chemonucleolysis, of those patients who had definite neurologic change in the form of reflex, sensory, or motor disturbance, 74 per cent had reverted to normalcy by the time of evaluation one year after injection. The most significant complication (anaphylaxis) was found in 1 per cent of our first 500 patients, but after we started using preoperative steroids along with other safeguards, we were able to control this complication. It is still something to be constantly on guard against. A mildly extruded nucleus pulposus is not a contraindication in chemonucleolysis. A sequestered one is. (table; see text) Patients who have had previous low back surgery have a lower percentage of satisfactory results than those who have not had previous surgery. Chemonucleolysis does not prejudice the chances of a good clinical result if a subsequent open surgical procedure is necessary. Preoperative psychological testing is a very effective predictor of end results in relation to pain relief from chemonucleolysis. Studies in our laboratory again confirm beyond a doubt that, in the dog, injection of very large amount of chymopapain in the epidural space of the lumbar spine has no effect on the subarachnoid contents, the dura, or the spinal nerves as they lie outside the dura and exit through the intervertebral foramina. The rare patient in whom there is a direct communication between the disc space and the subarachnoid space can be detected as the contrast medium is injected. If, by chance, chymopapain were inadvertently injected intrathecally, the maximum dose of that would be injected at any one level, 8 mg, would be well within the tolerable range in the human being.

Adult↗
PubMed1976

Treatment of spondylolisthesis and spondylolysis in children.

There are 2 fairly common types of spondylolisthesis in children - dysplastic and isthmic. The dysplastic type is secondary to congenital defects at the lumbosacral joint. The isthmic is usually due to a fatigue fracture of the pars interarticularis but there is also an hereditary element in this type. Most children with spondylolisthesis never develop significant symptoms and even of those who do, the vast majority can be treated without surgery. If symptoms persist or if further olisthesis is occurring, a one-level spinal fusion done through a paraspinal approach is recommended. It is most important not to allow olisthesis to develop to the point that the child shows the cosmetically undesirable stigmata characteristic of the condition. Solid fusion can be obtained in every case and will stop further slip.

Adolescent↗
PubMed1976

Spondylolysis in the female gymnast.

In a roentgenographic analysis of the lumbar spine of 100 young female gymnasts engaged in high-level competition, the incidence of pars interarticular defects was 11 per cent; 6 per cent had spondylolisthesis. This is 4 times higher than their non-athletic female peers. It appears that the female athlete may have the same incidence of pars interarticularis defects as the male performing similar activities. Pars defects developing in association with athletic activities may be distinct from those developing in early childhood. A negative lumbosacral roentgenographic series does not completely rule out a developing pars defect. Bone scintography offers an additional tool for evaluating early stress reaction in the pars, and suggests that if the athlete restricts vigorous activity, some will heal without progressing to roentgenographically detectable defects. Low back pain in the young gymnast should be a warning sign. Close scrutiny of pars interarticularis in these young athletes will reveal a high incidence of developing defects.

Adolescent↗
PubMed1975

Chymopapain chemonucleolysis in lumbar disk disease.

Experience with chymopapain chemonucleolysis in 1,200 cases of lumbar disk disease indicates that it is an effective method of relieving pain resulting from an abnormal intervertebral disk. Complications were few; anaphylaxis occurring immediately after injection was by far the most serious. With the use of a corticosteroid and an antihistamine in preoperative preparation, the incidence of anaphylaxis had dropped, although it still occurs. On long-term follow-up, chemonucleolysis appears to be as good as laminectomy in properly selected cases.

Anaphylaxis↗
PubMed1975

Fatigue fracture: the basic lesion is inthmic spondylolisthesis.

The defect in the pars interarticularis in spondylolysis and spondylolisthesis is most often the result of repeated trauma, stress, and factors other than acute fracture. These fatigue fractures develop early in life, may have a strong hereditary basis, and most often represent incidental roentgenographic findings. Attention should be given to the youngster or adolescent with low-back pain and paraspinal muscle spasm. If these patients are followed closely, the incidence of pars interarticularis defect is higher than appreciated. The lesion in some of these individuals may progress to significant vertebral slipping. If the developing defect is recognized early, treatment can be quite satisfactory.

Adolescent↗
PubMed1975

Preoperative psychological tests as predictors of success of chemonucleolysis in the treatment of the low-back syndrome.

Pre-injection psychological test scores, surgeon ratings, and patient biographical data were evaluated as predictors of success of chymopapain injection therapy in 130 patients who would otherwise have been treated by laminectomy. Three psychological tests were administered to each patient: the Minnesota Multiphasic Personality Inventory, the Cornell Medical Index, and the Quick Test (a measure of mental ability). In addition, the surgeons rated their patients on a five-point scale immediately after injection relative to their suitability for injection therapy and at one year relative to the objective and symptomatic results. The MMPI hysteria and hypochondriasis scales and the surgeon's rating of the psychogenic component of the patient's pain were predictive of the result of chemonucleolysis. The patient's biographical data which consisted of age, sex, marital status, occupation, and education were not related to postoperative outcome.

Adult↗