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Biomedical subjects

S I Esses

Publications and source records attributed to S I Esses.

51 records · Page 3Linked to original sources
PubMed1991

Repair of pars interarticularis defect. The prognostic value of pars infiltration.

Ten patients with symptomatic spondylolysis or Grade I spondylolisthesis were treated with the Buck method. At follow-up, nine patients were graded as successful. All patients fused. Pain relief, level of function, and likelihood of return to work were higher in patients preoperatively selected by lidocaine infiltration of the pars defect. Pars infiltration gives an accurate prediction of successful outcome following pars repair.

Adult↗
PubMed1991

Classification of pseudarthroses of the lumbar spine.

Imaging studies and operative records of 55 patients who had undergone lumbar pseudarthrosis repair were studied, providing a total of 85 surgically documented pseudarthroses. Preoperative imaging studies were carefully analyzed for the anatomic characteristics of the involved levels and the morphology of the fusion mass. The pseudarthroses were found to fall into four distinct morphologic categories: atrophic, transverse, shingle, and complex. The atrophic pseudarthrosis type was noted to be strongly associated with the presence of intact facet joints or spinal hardware. This retrospective analysis indicates that stress shielding provided by intact facet joints or spinal implants may contribute to graft atrophy in certain patients. The classification scheme proposed may be useful in future analyses of different fusion techniques in determining the various causes of this surgical complication.

Humans↗
PubMed1990

Evaluation of surgical treatment for burst fractures.

The authors instituted a prospective, randomized study of patients presenting with acute burst fractures of the thoracolumbar and lumbar spine. Patients were alternately treated by posterior distraction using pedicle instrumentation (AO fixateur interne) or anterior decompression and instrumentation (Kostuik-Harrington device). Forty patients are presented with a mean follow-up of 20 months. Preoperatively, there was significant canal compromise in 39 patients. This measured 44.5% in those patients undergoing posterior surgery and 58% in those patients undergoing anterior surgery. Postoperatively, this was reduced to 16.5% and 4%, respectively. There is a statistically significant difference between these two groups (P less than 0.0001). The mean preoperative kyphotic deformity was 18.7 degrees in those patients treated by anterior surgery and 18.2 degrees in the group treated by posterior surgery. At last follow-up, the mean improvement in kyphotic deformity was 9.3 degrees in the anterior group and 11.3 degrees in the posterior group. There is no statistically significant difference between these two groups. There were two implant failures of the anterior Kostuik-Harrington construct and two implant failures of the AO fixateur interne. Blood loss was significantly higher in the patients undergoing anterior surgery, but there were no complications from thoracotomy and anterior decompression of the dural sac. This study supports the hypothesis that posterior distraction instrumentation can effectively decompress the canal and correct kyphosis in patients sustaining burst-type injuries. Anterior surgery, however, results in a more complete and reliable decompression of the canal.

Adult↗
PubMed1990

Anterior cervical plate fixation with the titanium hollow screw plate system. A preliminary report.

Morscher, of Switzerland, has developed an anterior cervical spine plate system (THSP) that does not require screw purchase of the posterior cortex. This design eliminates potential neurologic complications usually associated with the anterior plate system, but maintains the mechanical advantages of internal fixation. The authors reviewed 13 consecutive patients in whom the THSP system was applied. Indications for the use of this device included acute trauma in three patients, trauma of more than 6 weeks' duration in five patients, and spondylosis in five patients. Fifteen plates and 58 screws were placed, with no screws purchasing the posterior cortex. Postoperative immobilization varied from no immobilization to four-poster brace. With a mean follow-up of 13 months, all 13 patients went on to fusion. One patient had screws placed in the disc rather than in bone and went on to malunion. In all other patients, radiographs did not demonstrate screw migration, screw-bone lucency, graft dislodgement, or malunion. No patient suffered neurologic injury as a result of this device. The THSP system facilitates reliable fusion with minimal complications. Its use should be considered in multilevel anterior spine defects, posttraumatic cervical kyphosis, and cervical fractures with posterior disruption requiring anterior fusion.

Adult↗
PubMed1989

Biomechanical properties of the proximal femur determined in vitro by single-energy quantitative computed tomography.

To assess the use of quantitative computed tomography as an in vivo predictor of fracture in the osteoporotic hip, we examined the in vitro relationship between single-energy quantitative computed tomography data, calibrated for scanner drift, and the mechanical properties of trabecular bone from the proximal femur. For 49 samples, the apparent density and ultimate strength were measured and their functional relationship to the computed tomography data determined. Apparent density demonstrated a moderate linear correlation to the computed tomography numbers (R2 = 0.60), and the ultimate strength was related through a power law (R2 = 0.83). In addition, for 8 intact femora, average computed tomographic data from the sub-capital region were moderately correlated to the ultimate fracture load applied under controlled in vitro conditions (R2 = 0.64). The average fracture energy for these femora was 43 J, a value more than an order of magnitude less than the energy available in a fall from standing height, suggesting that fall mechanics are a more important determinant of fracture risk than has been previously thought. The relationship between the energy absorbed to failure and the computed tomography data was best described by a power law (R2 = 0.90). Based on these results, it appears that quantitative computed tomography provides a potentially useful approach for the direct estimate of that component of fracture risk that can be attributed to a reduction in bone strength.

Aged↗
PubMed1989

The AO spinal internal fixator.

The AO spinal internal fixation system uses 5.0 mm diameter transpedicular Schanz screws with 7.0 mm diameter fully threaded stainless steel rods. Originally developed for the treatment of thoracolumbar and lumbar spine fractures, it can be used for a variety of spinal disorders. A prospective study has been carried out, and the first 48 patients have been reviewed. The results for those patients with fractures are excellent. In burst fractures, it has been possible to decompress the canal and restore lordosis. In only half of the cases of spondylolisthesis has it been possible to improve the degree of slip. The fixator has provided rigid stabilization for a variety of other spinal problems.

Adolescent↗
PubMed1989

The role of external spinal skeletal fixation in the assessment of low-back disorders.

A variety of tests are currently used in an attempt to predict pain relief following arthrodesis of the lumbar and lumbosacral spine. External spinal skeletal fixation provides a means by which specific spinal motion units can be rigidly immobilized. A trial of temporary external fixation was investigated for its value in predicting the outcome of surgical fusion. Thirty-five patients with chronic low-back pain have been prospectively studied. The results show a statistically significant superiority of temporary external spinal fixation in predicting surgical result as compared with plain radiographs, discograms and facet blocks.

Adult↗
PubMed1989

The spinal pedicle screw: techniques and systems.

New spine instrumentation systems are being developed that incorporate pedicle screws for purchase. This review article outlines techniques for the safe insertion of these devices. A description of the various screw-rod and screw-plate systems currently available is presented.

Biomechanical Phenomena↗
PubMed1988

The placement and treatment of thoracolumbar spine fractures. An algorithmic approach.

Advances in imaging techniques and surgical instrumentation systems have made the selection of appropriate treatment for thoracolumbar fractures difficult. A review of the literature and personal cases have led to the development of a series of algorithms for patient care. Fracture patterns with recommended therapeutic approaches are presented and discussed.

Algorithms↗
PubMed1984

Use of a pylon for early ambulation after below-knee amputation: a preliminary report.

The fitting of a prosthesis immediately after amputation offers many advantages. These include early ambulation, more rapid healing of the amputation site and a decrease in the number of complications resulting from prolonged bed rest. The major problems preventing the widespread use of immediate fitting are the specialized prosthetic care required and the high cost of the appliance. The authors describe a new pylon designed for early ambulation after below-knee amputation. Its application does not require special training, it is inexpensive, safe and effective. This pylon was used in the early postoperative period in 20 amputees, without any major complications.

Adult↗
PubMed1983

Spinal arachnoiditis.

A review of the literature points to the many causes of arachnoiditis and the failure of treatment to arrest or reverse its effects. The true incidence cannot be determined, although it is probably lower than might at first appear from the published articles. In the radiological literature the diagnosis seems to derive from an examination of the films alone, often without reference to the clinical findings or appearance at operation. While attempts at treatment are usually unsuccessful, some iatrogenic cases can be prevented by the avoidance of intrathecal steroid injections or unduly rough or repeated surgical exploration of the lumbar vertebral canal.

Animals↗
PubMed1983

Donor marrow-derived cells as immunogens and targets for the immune response to bone and skin allografts.

The relative importance of donor marrow-derived cells in the immunogenicity of bone and skin allografts was compared. Radiation chimeras were created to have marrow-derived cells (MDCs) of a different genotype from their nonmarrow-derived cells (NMDCs). Such animals were used as donors of bone or skin for recipients chosen so that either the MDCs or the NMDCs of the graft would be incompatible. Immunogenicity was determined by measuring the recipient antibody response. The effect of the immune response on the bone graft (rejection) was determined by impaired bone healing. When MDCs alone were H-2 disparate with the recipient, bone grafts were immunogenic, and the bone graft healing was impaired. In contrast, skin grafts in the same combinations were immunogenic but were not rejected if the differences were only expressed on the MDCs of the graft. The role of NMDCs in all of these experiments was more difficult to interpret, but the results suggested that NMDCs are relatively unimportant for healing of bone grafts, although critical for rejection of skin grafts. We conclude that, unlike the situation with skin grafts, the major inducers and targets of the immune response to bone allografts are marrow derived.

Animals↗
PubMed1981

Electrical burns; pathophysiology and complications.

The authors review the pathophysiology and complications of electrical injuries. Such injuries can be categorized into direct electrical injuries, arc burns and flame burns. Each has a distinct appearance and prognosis. Nine patients with electrical injuries were admitted to the Toronto General Hospital over the 5-year period 1973 to 1978. All were men and the average age was 33 years. Five patients required amputation. In one patient a convulsive disorder developed 3 weeks after injury. One patient demonstrated peripheral nerve injury with complete axonal lesions of the right median and ulnar nerves; there was progressive full return of nerve function over 12 months. Direct electrical injury to nerves is usually transient and return of function can be expected unless there has been a concomitant thermal or mechanical injury.

Acute Kidney Injury↗