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Biomedical subjects

E N Hanley

Publications and source records attributed to E N Hanley.

11 recordsLinked to original sources
PubMed1992

Immediate postoperative stability of the atlantoaxial articulation: a biomechanical study comparing simple midline wiring, and the Gallie and Brooks procedures.

A biomechanical study was undertaken to quantitate the immediate postoperative stability of the atlantoaxial articulation after stabilization by simple midline wiring, as well as the Gallie and Brooks procedures. Fresh adult cadaveric cervical spines were mounted for testing such that only the C1-2 motion segment and the load deflection curves generated in flexion, extension, and torsion moved. Spines were tested after the creation of a fracture at the base of the odontoid process with transection of the transverse ligament and after stabilization by each of the surgical techniques. Mean apparent stiffness values evaluated the biomechanical properties of these three commonly performed procedures. Although all tested procedures restored supraphysiologic mechanical properties in all modes tested (p less than 0.001), the Brooks technique was stiffer than the other two methods (p less than 0.001). Although many factors must be considered when selecting a particular surgical technique, the biomechanical data obtained in this study may be of assistance to the surgeon in choosing the type of construct for upper cervical stabilization and arthrodesis.

Adult↗
PubMed1992

Vascular surgery: possible adverse effect on extent of subsequent lower limb amputation.

The influence of previous vascular surgery on the level of amputation was examined retrospectively in 345 amputations (66 bilateral) in 279 patients with peripheral vascular disease. Seventy-two patients (38% diabetic) had previous vascular surgery on 74 limbs and 207 (65% diabetic) had no history of vascular surgery on 271 limbs. In patients with previous vascular surgery, above-knee amputation was done on 55% of limbs versus 71% of limbs in patients with no previous vascular surgery (P < .05), despite a lower incidence of diabetes in the former group. We conclude that although reconstructive vascular surgery is an effective treatment for vascular insufficiency, occasionally it not only fails, but is associated with an increased incidence of above-knee amputation.

Aged↗
PubMed1992

Junctional burst fractures.

Twenty-two patients with burst fractures in this mechanically and neurologically distinct region (T11-L2) were studied at injury and after acute surgical reduction and stabilization (antikyphosis and ligamentotaxis concept). Canal compromise averaged 42% (10-82%) before surgery, and at follow-up 14% (0-46%), segmental kyphosis 15 degrees (4 degrees-27 degrees) and 3 degrees (0 degree-15 degrees), and vertebral segment height 62% (41-85%) and 86% (60-100%), respectively. Incomplete patients gained an average of 1.8 Frankel subgrades. The described treatment can predictably recanalize the spine, correct deformity, and stabilize neurologic compromise. A significant correlation between postoperative neurologic status and the radiographic criteria under study could not be established.

Adolescent↗
PubMed1992

Types of anterior cervical grafts.

Anterior cervical diskectomy and fusion provide satisfactory results in most instances of cervical disk herniation and cervical spondylosis. A variety of interpositioned grafts have been described for such problems at one or two levels. Multiple level anterior decompression and fusion for patients with spondylotic myelopathy produce satisfactory results in most instances and are particularly effective when a degenerative kyphosis is present. Appropriate patient selection and attention to technical aspects of exposure, neural decompression, and graft procurement and placement directly influence the surgical outcome.

Bone Transplantation↗
PubMed1979

Bone stress: a radionuclide imaging perspective.

Thirty-five college athletes with lower leg pain underwent radiography and radionuclide studies to rule out a stress fracture. Their asymptomatic extremities and 13 pain-free athletes served as controls. Four main patterns were observed: (a) sharply marginated scintigraphic abnormalities and positive radiographs; (b) sharply marginated scintigraphic abnormalities and negative radiographs; (c) ill-defined scintigraphic abnormalities and negative radiographs; and (d) negative radionuclide images and negative radiographs. Since the patients with the first two patterns were otherwise identical medically, the authors feel that this scintigraphic appearance is characteristic of bone stress in the appropriate clinical setting, regardless of the radiographic findings. A schema is proposed to explain the occurrence of positive radionuclide images and negative radiographs in the same patient, using a broad conceptual approach to the problem of bone stress.

Adolescent↗
PubMed1978

Ferrographic analysis of wear particles in arthroplastic joints.

Analysis of aspirated synovial fluid appears to be a useful method for the study of the rates, mechanisms, and biological responses to wear in surgical joint replacements. Ferrography, an industrial technique of magnetic separation of particulate matter from samples of lubricating solutions, allows separation of wear debris from synovial fluid. Bichromatic microscopy and SEM X-ray analysis permit identification of metallic particles from arthroplastic joints. Polarized light microscopy characterizes and differentiates polyethylene and polymethacrylate debris. The number and morphology of the wear particles in synovial specimens from arthroplastic joints correlate with the rate and the mechanisms of wear, as confirmed by examination of the implant and the adjacent synovial tissue.

Color↗
PubMed1978

Failed lumbar disc surgery requiring second operation. A long-term follow-up study.

Forty-five patients who had lumbar disc surgery 10 or more years previously, and had required a second operative procedure, have been evaluated. Failures occurred up to 16 years after the first operation, and were most commonly due to pseudoarthrosis in the patients who underwent spinal fusion initially, and to recurrent disc lesions at the same level as previous surgery in the patients who did not have fusion. The clinical and functional results in the second group of patients who required a second procedure were comparable to those of patients who required only a single procedure. In contrast, patients who had undergone spinal fusion who required a second procedure had significantly worse clinical and functional results, both in comparison to the patients who did not undergo fusion as well as to patients who had had fusion as a single procedure. The only predictable, demonstrable source of failure was acquired spondylolysis. Frequently, repair of pseudoarthrosis did not lead to symptomatic relief. These data suggest that spinal fusion, when it fails, has a significantly worse prognosis than simple disc excision in the management of lumbar disc disease.

Adult↗
PubMed1978

Experimental fracture healing: evaluation using radionuclide bone imaging: concise communication.

Radionuclide bone imaging was performed in a rabbit model to observe the course of fracture healing and to establish criteria for distinguishing nonunion and delayed healing from normal healing. Sequential gamma-camera images (with pinhole collimator) were collected and subjected to computer analysis. Five groups were established: a) control--immobilization; b) control--immobilization plus periosteal stripping; c) simple fracture--osteotomy; d) delayed union--osteotomy plus periosteal stripping; and e) nonunion--osteotomy, periosteal stripping and polymethyl methacrylate interposed between fracture fragments. Histographic representation of absolute count rates along rabbit tibias followed a predictable pattern in the simple-fracture and delayed-union groups. They differed only in the time of appearance of phases. The nonunion group demonstrated no recognizable sequential pattern. In this experimental model, serial bone scanning with quantitative data analysis has shown potential for indicating the course of healing in fractures and for serving as a guide to treatment.

Animals↗
PubMedDate not supplied

A comparison of radiographic findings in fusion and nonfusion patients ten or more years following lumbar disc surgery.

Ninety-six patients who had undergone disc excision and midline spinal fusion and 36 patients who had had simple disc excision had spinal radiographs made 10 or more years postoperatively. Claw spurs were found most commonly at the L2-3 and L3-4 levels in fusion patients, particularly male laborers. Traction spurs with segmental hypermobility were found more commonly at the L4-5 level in patients whose spines were not fused, particularly women. Total lumbar flexion-extension was greater in nonfusion than in fusion patients, but the L1-3 mobility was greater in those who had undergone fusion, suggesting a compensatory increase in the range of lumbar motion. Segmental mobility at levels of surgery in nonfusion patients was similar in those with good and those with poor clinical results. Disc space narrowing was common at levels of operation, but did not correspond to the clinical result. Pseudarthrosis was demonstrated in 26% of fusion patients, but was of no clinical significance. Although complex radiographic changes follow lumbar disc surgery, with or without failure, it is concluded that the plane radiograph is of little aid in determining the source of postoperative pain. The sole exception is that of acquired spondylolysis, which was found in 2.5% of this group of fusion patients, and was clearly associated with a poor clinical outcome. Symptomatic degenerative disc disease at levels above lumbar spinal fusions appears to be an uncommon clinical problem.

Female↗
PubMedDate not supplied

Accurate roentgenographic determination of lumbar flexion-extension.

Although many techniques have been devised for the roentgenographic measurement for angular motion in the lumbar spine, all present technical and visual problems. No previously described method has been subjected to a test of accuracy or reliability. A transparent plastic sheet technique provides a reproducible and accurate method for quantitative evaluation of flexion-extension motion in the lumbar spine.

Humans↗