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Biomedical subjects

T A Damron

Publications and source records attributed to T A Damron.

16 recordsLinked to original sources
PubMed1996

Ewing's sarcoma of the proximal femur.

The cases of 16 patients with Ewing's sarcoma of the proximal femur treated in the era of multiagent chemotherapy were reviewed, with emphasis on the mechanical problem of tumor involvement in this structurally demanding site. Fourteen patients received chemotherapy and local radiotherapy as the initial primary treatment. One patient had chemotherapy and radiotherapy, followed by wide local resection. One patient had amputation, followed by chemotherapy, for pathologic fracture and extensive soft tissue involvement at presentation. Two local recurrences occurred. Excluding the 2 patients whose femurs were fixed prophylactically, the pathologic fracture rate was 79%. In addition, by excluding the 2 patients who died before fracture, the pathologic fracture rate was 92%. Nonunion occurred in 5 (71%) of the 7 pathologic fractures not treated by resection and required as many as 5 additional surgical procedures to obtain union. At latest followup evaluation (average, 6.3 years), 10 patients had no evidence of disease, 1 was alive with disease, and 5 had died of their disease. Options for management should include primary resection and reconstruction or prophylactic internal fixation after completion of chemotherapy plus or minus radiotherapy.

Adolescent↗
PubMed1995

Arthrodesis following failed total knee arthroplasty: comprehensive review and meta-analysis of recent literature.

With the increasing duration of follow up on total knee arthroplasties, more revision arthroplasties are being performed. When revision is not advisable, a salvage procedure such as arthrodesis or resection arthroplasty is indicated. This article provides a comprehensive review of the literature regarding arthrodesis following failed total knee arthroplasty. In addition, a statistical meta-analysis of five studies using modern arthrodesis techniques is presented. A statistically significant greater fusion rate with intramedullary nail arthrodesis compared to external fixation is documented. Gram negative and mixed infections are found to be significant risk factors for failure of arthrodesis.

Adult↗
PubMed1995

Ewing's sarcoma.

Explore the source record for details and available documents.

Antineoplastic Agents↗
PubMed1995

Current combined treatment of high-grade osteosarcomas.

The evaluation and treatment of osteosarcoma have evolved considerably over the past 2 decades, with corresponding dramatic improvements in prognosis. In large part, the improved outlook is attributable to intensive multiagent adjuvant chemotherapy, with better imaging modalities and reconstructive techniques also playing an important role. The current standard treatment for nonmetastatic osteosarcoma includes neoadjuvant chemotherapy, limb-sparing "wide" surgical resection, and reconstruction of the defect. Approximately 80% of patients are spared amputation. Limb salvage should be considered when an adequate surgical margin is attainable without significant neurovascular compromise and the surgical reconstruction is likely to provide better function than amputation. Because a good chemotherapeutic response is an important favorable prognosticator, much recent attention has been focused on predicting response preoperatively to allow closer surgical margins. Aggressive surgical treatment of pulmonary metastases has also been of measurable benefit.

Bone Neoplasms↗
PubMed1995

Subcutaneous involvement after a metacarpal chondrosarcoma. Case report and review of literature.

The relatively high probability of local recurrence after excision of chondrosarcomas has been attributed to the avascularity of the cartilage tumor matrix, making the neoplastic cells less dependent on an extrinsic blood supply. This report is of a case of subcutaneous involvement by chondrosarcoma from a metacarpal to a site on the ipsilateral forearm several centimeters remote from the resection incision in the absence of local recurrence or pulmonary metastases. The pertinent literature regarding cutaneous involvement, local recurrence, and transplantation of cartilage neoplasms is reviewed.

Aged↗
PubMed1994

Biomechanical analysis of dorsal plate fixation in proximal phalangeal fractures.

The biomechanical properties of three minifragment plate and screw systems were compared to determine whether plate systems primarily designed for maxillofacial reconstruction are biomechanically sound for use in proximal phalangeal fracture fixation. A middiaphyseal transverse osteotomy was created in each of 30 fresh-frozen human proximal phalanges to simulate an unstable fracture. Each osteotomy was then fixed with four 2.0ml screws through one of three different four-hole minifragment plates in a middorsal position. Plating systems tested included a vitallium plate with self-tapping screws (Luhr), a stainless steel plate with tapped screws (Synthes), and a titanium plate with tapped screws (Synthes). Testing was performed to failure in an apex volar three-point bending mode. The titanium-plated phalanges were the stiffest construct and required the greatest load and total energy absorbed to failure. However, only the load to failure for titanium versus stainless steel was significantly different. Therefore, there is no biomechanical disadvantage to using the titanium or vitallium plate and screw systems in the setting of unstable proximal phalangeal fractures.

Biomechanical Phenomena↗
PubMed1994

A biomechanical analysis of prophylactic fixation for pathological fractures of the distal third of the humerus.

Twenty-four matched pairs of fresh-frozen humeri from human cadavera were divided randomly into four groups, in order to determine the most biomechanically desirable construct for the prophylactic fixation of impending fractures of the distal third of the humerus. Group I comprised intact humeri and matched humeri in which a 50 per cent lateral, semicylindrical cortical defect of the distal third had been created, resulting in a reproducible model of an impending fracture due to a lytic defect involving 50 per cent cortical disruption at the distal end of the humeral medullary canal. In Group II, such a lateral defect was created in both the right and the left, matched humeri. Group III was composed of humeri in which the defect had been fixed prophylactically with a single plate and the contralateral humeri, which had been treated with double-plating. Group IV comprised specimens in which the defect had been fixed with double-plating as well as those fixed with Rush rods. The fixation of each specimen in Groups III and IV was supplemented with bone cement. Each specimen was tested in torsion to failure, and the resulting peak torque, torsional stiffness, and total energy absorbed were analyzed for each group. The Group-I specimens that had a defect had a significantly lower (p < 0.05) peak torque, torsional stiffness, and total energy absorbed than the intact specimens; all of the specimens with a defect failed at the defect, and all of the intact specimens failed proximally. In Group II, there was a high side-to-side association with respect to peak torque, torsional stiffness, and total energy absorbed.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗
PubMed1994

Surgical treatment of mallet finger fractures by tension band technique.

A retrospective review was performed of 19 patients with irreducible mallet finger fractures after failed splinting. The patients were treated with open reduction and a tension band technique. Follow-up results were available for 18 patients (95%) at an average 8.2 years postoperatively. Eighty-nine percent of patients had no clinical mallet deformity, troublesome pain, or major functional disability. Distal interphalangeal range of motion averaged 1 degree hyperextension to 69 degrees flexion. All fractures healed with a congruent articular surface. Minor nonmechanical complications were encountered in 11% of cases in which a suture was used as the tension band material. Successful treatment may thus be achieved surgically in this select subset of mallet finger fractures when this technique is employed.

Adolescent↗
PubMed1994

Chronologic outcome of surgical tendoachilles lengthening and natural history of gastroc-soleus contracture in cerebral palsy. A two-part study.

Medical records of 59 patients with cerebral palsy were reviewed retrospectively to evaluate results of tendoachilles lengthening. Surgical lengthening resulted in highly significant (p < 0.0001) initial average gains in dorsiflexion compared with baseline. These average improvements maintained their statistical significance for seven years postoperatively. The arc of motion was not significantly different postoperatively. The initial ambulatory level was improved in 55% of the patients and maintained in the remainder. However, 14 ankles (11.9%) in eight patients (13.6%) required repeat tendoachilles lengthening during the study period, primarily after gastrocnemius procedures. Calcaneus deformity occurred in 1.7% of the surgically treated ankles. To evaluate the potential for spontaneous improvement over time in fixed equinus deformity, the records of a group of 68 additional cerebral palsy patients were reviewed. Patients treated nonoperatively despite two examinations that demonstrated fixed lack of dorsiflexion, while not representing a true control group, showed no spontaneous improvement in equinus deformity through seven years postoperatively.

Achilles Tendon↗
PubMed1993

Case report 803: Gorham's disease (Gorham-Stout syndrome) of scapula.

In summary, a 36-year-old man presented with pain and limited motion in the shoulder. Clinical examination revealed obliteration of normal scapular landmarks in the conspicuous absence of any palpable soft tissue mass. Roentgenograms showed progressive osteolysis of the scapula. Biopsy confirmed the diagnosis of Gorham's disease. MRI played a key role in defining the extent of disease involvement and in displaying the distinct soft tissue anatomy. These MRI features are to our knowledge previously undescribed.

Adult↗
PubMed1993

Biomechanical analysis of mallet finger fracture fixation techniques.

A biomechanical study was conducted to determine the best fixation technique for mallet finger fracture among four commonly used methods. Considerations were technical complications, biomechanical properties, and maintenance of reduction. Techniques tested included Kirshner wire, figure-of-eight wire, tension band wire, and tension band suture. Technical complications were frequent with both the Kirschner wire and tension band wire techniques. Biomechanical testing yielded significantly greater energy absorbed to failure and a trend toward greater peak loads to failure for both the figure-of-eight wire and tension band suture techniques. Irreversible loss of reduction during testing occurred in all of the Kirschner wire-fixed fractures, in 60% of the tension band wire-fixed fractures, and in 50% of the figure-of-eight wire-fixed fractures. No irreversible failure occurred in the tension band suture group.

Aged↗
PubMed1993

Rapidly progressive protrusio acetabuli in patients with rheumatoid arthritis.

Current literature suggests protrusio acetabuli in patients with rheumatoid arthritis progresses at a gradual rate of 2-3 mm per year. This report presents five patients with rheumatoid arthritis (RA) who experienced rapidly progressive protrusio. The period of rapid clinical progression averaged 40 days. During progression, medial protrusio increased an average of 7.5 mm, superior protrusio advanced 6.9 mm, femoral head width decreased 2.7 mm and center-edge angle increased 20.7 degrees. Axial protrusio occurred along an axis 137 degrees from vertical. A key clinical feature was an absence of significant hip symptoms before a marked increase in symptoms over a period of days to several weeks, resulting in a significant decrease in the patient's ambulatory capacity. Osteopenia was a consistent preexisting radiographic feature. The findings underscore the existence of rapidly progressive protrusio in the natural history of RA and its importance in the differential diagnosis of hip pain in patients with RA. Early recognition is important to minimize the potential complications of delayed surgical treatment.

Acetabulum↗
PubMed1989

Gangliocytic paraganglioma in association with a duodenal diverticulum.

Gangliocytic paraganglioma is an extremely rare benign neurogenic tumor nearly exclusively located in the second portion of the duodenum, also the most common site of duodenal diverticula. A case is reported of a gangliocytic paraganglioma presenting in a 65-yr-old woman with a 1-yr history of postprandial cramping abdominal pain culminating in a single episode of melena leading to laparotomy. The tumor was identified with difficulty by endoscopy following negative barium studies. Histologically, the tumor is composed of carcinoid-like cells admixed with varying numbers of ganglion cells in a substratum of neuroid spindle cells. The epithelioid cells contain argyrophilic cytoplasmic granules confirmed by electron microscopy to be dense core membrane-bound secretory granules. Review of the literature suggests the tumor described is typical both clinically and pathologically of gangliocytic paraganglioma of the duodenum, except for its unprecedented occurrence in association with a duodenal diverticulum.

Aged↗
PubMed1987

Cytochemical demonstration of neuromelanin in black pigmented adrenal nodules.

Retrospective review of 363 consecutive autopsy reports in which adrenal examination was noted reveal 8 cases of pigmented adrenal nodules. Black pigmented adrenal nodules have been reported infrequently both as incidental autopsy findings and in association with Cushing's syndrome. The nature of the pigment in these lesions has been assumed to be lipofuscin. Gross and histologic study of seven cases and electron microscopic study of two cases suggest the presence of a neuromelanin component in the pigment, a previously unreported finding in the adrenal cortex. Review of the clinical records of the patients suggested no associations with specific underlying disorders. The prevalence the authors report (2.2%) is less than that of a previous prospective study.

Adolescent↗
PubMedDate not supplied

Diminished knee flexion after hamstring surgery in cerebral palsy patients: prevalence and severity.

A review of pre- and postoperative prone knee flexion (PKF) data after isolated hamstring tenotomy for 52 patients with cerebral palsy (CP) at an average follow-up of 3 years 4 months showed the frequency of diminished knee flexion to be 71%. Twenty-three percent of the knees actually had improved flexion, whereas 6% were unchanged. On the average, patients' flexion decreased 14.4 degrees from a preoperative PKF of 131.5 degrees to 117.1 degrees postoperatively (p < 0.0001). Only 11.5% of patients had PKF < 90 degrees at most recent follow-up, however; only 1.9% had PKF < 60 degrees. Thirteen percent of ambulators eventually required a rectus femoris transfer to correct "stiff-legged gait."

Adolescent↗