Biomedical subjects

D R Chandler

Publications and source records attributed to D R Chandler.

5 recordsLinked to original sources

PubMed1992

Emergency cervical-spine immobilization.

STUDY OBJECTIVE: To determine the effectiveness of a cervical-spine immobilization using a rigid cervical extrication collar and an Ammerman halo orthosis with and without spine boards. DESIGN: A mixed model multivariate design with one within factor (device type) and one between factor (spine board application). SETTING: Radiology suite. TYPE OF PARTICIPANTS: Twenty normal men with a mean age of 29.6. INTERVENTIONS: Unrestrained cervical motion was compared with motion in a cervical extrication collar and an Ammerman halo orthosis with and without a spine board. MEASUREMENTS: Photographic measurement of head and neck motion during maximal flexion-extension, lateral bending, and rotation. Radiologic measurement of maximal intervertebral flexion-extension. MAIN RESULTS: Both cervical extrication collar and Ammerman halo orthosis significantly reduced motion in all planes (P less than .001) with the Ammerman halo orthosis reducing these motions significantly more (P less than .001). With the use of a spine board these motions were restricted even more (P less than .001). The Ammerman halo orthosis with a spine board provided the greatest immobilization, equivalent to that provided by an halo-vest. CONCLUSION: A rigid cervical collar and a spine board provide significantly better immobilization than the collar alone. Further immobilization is provided by an Ammerman halo orthosis.

Adult↗

PubMed1988

Diaphyseal intraosseous ganglion.

Ganglion cysts of bone are noted to occur most often in the metaphysis of epiphysis of a long bone. A unique ganglion cyst, developing in a diaphyseal location, was excised from the leg of a 14-year-old boy. The follow-up examination showed no recurrence one year following surgery.

Adolescent↗

PubMed1988

Carpal tunnel syndrome in paraplegic patients.

Thirty-eight (49 per cent) of seventy-seven paraplegic patients whose level of injury was at or caudad to the second thoracic vertebra were found to have signs and symptoms of carpal tunnel syndrome. The prevalence of carpal tunnel syndrome was found to increase with the length of time after the injury. In the eighteen patients in whom manometric studies were done, the carpal tunnel pressures when the wrist was in the neutral position were higher than those that have been reported in non-paraplegic patients who did not have carpal tunnel syndrome but were lower than the values in non-paraplegic patients who did have the syndrome. When the wrist was in flexion, the pressures were similar to the values that have been reported for non-paraplegic patients. However, in the paraplegic patients, regardless of whether or not they had carpal tunnel syndrome, the pressures that developed when the wrist was in extension were significantly higher than those in non-paraplegic patients, regardless of whether or not they had carpal tunnel syndrome. Most of the activities of daily living of paraplegic patients, including the maneuver to relieve ischial pressure that consists of arising from the seated position using the extended arms, are performed with the wrists locked in maximum extension. The pressure that develops in the carpal canal during this forced extension of the wrist, probably combined with the repetitive trauma to the volar aspect of the extended wrist while propelling a wheelchair, contributes to the high frequency with which carpal tunnel syndrome is found in paraplegic patients.

Activities of Daily Living↗

PubMed1984

Radiographic assessment of acetabular cup orientation. A new design concept.

An acetabular cup with a 270 degree rim wire has been designed to assist in the radiographic assessment of acetabular cup orientation in total hip arthroplasty. A study was conducted analyzing the component in various positions of lateral opening and version with three different X-ray-beam centering positions. The 270 degree acetabular rim wire allowed for easy and accurate assessment of component orientation when the pelvis was level and the central ray of the X-ray beam was centered over the hip.

Acetabulum↗

PubMed1982

Prosthetic hip range of motion and impingement. The effects of head and neck geometry.

Two major design parameters to total hip arthroplasty which can be selected to optimize for anatomical variation are head diameter and neck length. By using a cadaveric pelvis mounted in a three-dimensional protractor, it was shown that increased head-neck diameter ratio results in increased range of motion, with decreased prosthetic impingement, and that increased neck-length results in increased range of motion, with increased prosthetic impingement. Head diameter has no range of motion effect in arcs characterized exclusively by bony impingement, and neck length has no range of motion effect in arcs characterized exclusively by prosthetic impingement. The surgeon is currently confronted with a variety of prostheses with different head-neck diameter ratios and neck lengths. When choosing the optimal prosthesis for a particular patient, the surgeon is often restricted by various anatomical constraints. While a large head diameter cannot always be chosen, an adequate range of motion without prosthetic impingement can still be achieved by ensuring that head-neck diameter ratio is optimum. A sufficient neck length to ensure adequate range of motion is desirable, but the neck should not be so long that neck-socket impingement is of concern. Optimum clinical range of motion, with minimal prosthetic impingement, may be achieved with a large head size and a medium neck length.

Biomechanical Phenomena↗