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Biomedical subjects

H H Sherk

Publications and source records attributed to H H Sherk.

At least 19 recordsLinked to original sources
PubMed1992

Holmium:YAG laser arthroscopy of the temporomandibular joint.

A new pulsed midinfrared laser has become available for use in arthroscopic surgery of the temporomandibular joint (TMJ). This article reviews holmium:YAG (yttrium-aluminum-garnet) laser physics, its tissue effects, and reports initial experience with its use in TMJ arthroscopy. Because the Ho:YAG laser can precisely and rapidly resect cartilaginous tissues with only moderate necrosis, can function in a saline environment, and can be transmitted through conventional optical fibers, it has the potential of becoming a useful and adaptable system for TMJ arthroscopic surgery.

Arthroscopy↗
PubMed1992

Laser arthroscopy.

Lasers have become widely used in several medical and surgical disciplines. In ophthalmology and plastic surgery, their use has permitted the development of therapeutic modalities that would have been otherwise impossible. In such specialties as gynecology and general surgery, lasers provide advantages that make certain procedures more convenient and easier to perform. In contrast, orthopaedic surgeons have, to date, been slow to accept these devices into the therapeutic armamentarium. The purpose of this paper is to describe the status of laser use in the orthopaedic subspecialty of arthroscopy.

Arthroscopy↗
PubMed1992

Accurate compartment pressure measurement using the Intervenous Alarm Control (IVAC) Pump. Report of a technique.

This study demonstrates the accuracy of a common, readily available pressure transducer system (IVAC pump) for the measurement of compartment syndromes. An in vitro assay was used to compare the accuracy of the IVAC pump manometer with the Hewlett-Packard monometer (HP78532B) and a miniaturized digital fluid pressure manometer (Stryker). The IVAC pump was accurate within 2.4 mm Hg difference of the HP78532B and Stryker manometers. Twenty-five patients suspected of having compartment syndrome posttibial fracture had compartment pressures measured using the IVAC pump. In all the patients, compartment syndrome was accurately assessed (positive in one case and negative in the remainder). The IVAC pump is readily available in most hospitals. It is easy to use and provides accurate measurements of compartment pressures.

Compartment Syndromes↗
PubMed1991

Treatment versus non-treatment of hip dislocations in ambulatory patients with myelomeningocele.

Thirty myelomeningocele patients with untreated hip dislocations who had functional quadriceps and good ambulatory capability were evaluated for hip pain, hip motion and sitting ability: they had no pain, good to excellent hip motion and no difficulty in sitting. Three were wheelchair-bound. Nine had a limb-length inequality requiring a shoe lift. They were compared with a similar series of 11 patients who underwent open reduction of a dislocated hip with a two-year follow-up. Two patients in this group had improved and three had worse sitting balance. Serious perioperative complications occurred in six patients. The authors conclude that surgical reduction of paralytic hip dislocations in ambulatory myelomeningocele patients is costly and offers little obvious benefit.

Adolescent↗
PubMed1991

Contamination of operating room personnel during total arthroplasty.

The authors prospectively evaluated the degree of contamination to the operating room team during 60 consecutive total joint arthroplasties. Each member of the team was required to wear a hood, mask, protective eyewear, and shoecovers. At the conclusion of each procedure, all members were assessed in terms of degree and location of contamination. One hundred percent of the surgeons and first assistants were exposed. The face and eyewear were noted to be the area of greatest contamination. The authors found orthopedic surgeons to be at significant risk of contamination with blood and body fluids during total joint arthroplasty.

Blood↗
PubMed1988

Biomechanical evaluation of the extensor musculature of the cervical spine.

Dissection of the musculature in the cervical spines of four cadavers indicated that the semispinalis cervicis and capitis muscles appeared to be the muscles primarily responsible for extension of the cervical spine and head. The minimum force needed to balance a biomechanical model of the cervical spine in the neutral prone position against gravity measured 14.38 kg. The values obtained with this model, with roentgenograms of the cervical spine, and vector analysis were close enough to establish that the model is apparently valid for studying the extensor musculature of the cervical spine. Because the extensors appear to generate considerable force and may act as significant dynamic stabilizers of the cervical spine, the authors have altered their posterior surgical approach to minimize disruption of the extensor musculature.

Cervical Vertebrae↗
PubMed1988

The vertical stability of the cervical spine.

The concept of the three-column cervical spine and load transmission through each column was experimentally tested. Material consisted of five cervical columns removed from cadavers. The experiment was conducted on an Instron load testing machine. Load was applied on superior articular surfaces of the axis vertebra and was recorded below from each column separately at the level of the sixth cervical vertebra. It was found that 36% of the total load applied on the top of the specimen is transmitted through the anterior column formed by bodies and intervertebral discs and 32% each through the two posterior cervical columns formed by the articular processes. The experiment very strongly supported the role of neural arch in transmission of vertebral compressive forces.

Biomechanical Phenomena↗
PubMed1988

High resolution analysis of ground foot reaction forces.

A new system of hardware and software has been designed for quantitative high resolution analysis of ground foot pressures during stance and gait. In the system, a large photoelastic sheet is used as the transducer and a computerized video system for analysis and display. This system offers a larger active surface at higher resolution and at lower cost than any other system heretofore described. It will be used to predict diabetic plantar ulceration as well as to detect anatomic and motor defects affecting the feet.

Computer Graphics↗
PubMed1988

Treatment of tumors of the cervical spine.

In 34 patients with primary or metastatic tumors of the cervical spine over a ten-year period, the presenting symptom was neck pain. Eleven patients demonstrated evidence of radiculopathy, one a myelopathy, and three a combined myeloradiculopathy. Surgical stabilization, combined in eight cases with cord decompression, successfully relieved pain and prevented further neurologic deterioration in 17 of 18 patients with radioresistant tumors. Complications included two patients who were treated with short posterior fusions displacing as a result of tumors progressing above and below the fusion, and one patient in whom an anterior methacrylate mass became dislodged and appeared to jeopardize the esophagus. Methacrylate was used to augment the grafts posteriorly to facilitate early mobilization without the need for a halo splint. Mean patient survival was not significantly increased by surgical intervention (26 weeks vs. 20 weeks). While most lesions of the cervical spine can best be managed by nonoperative methods, in selected patients long posterior fusion with wires and methacrylate appears successful in relieving pain, halting progress of neurologic deficits, and facilitating early mobilization.

Adolescent↗
PubMed1987

The natural history of hip dislocations in ambulatory myelomeningoceles.

We studied 22 myelomeningocele patients with strong quadriceps and good ambulatory capability who had a dislocated hip. These patients did not have hip pain, had good to excellent hip motion and could sit with no difficulty. All but one was a good to excellent community ambulator with crutches and orthoses. Twenty-five percent had limb length inequality requiring shoe lifts but this combination did not impair functional capability. None owned wheelchairs. Seven had associated musculo-skeletal deformities which required treatment. We concluded that the hip dislocation in these patients was not significant. We evaluated a similar series of 11 patients who had open reduction of a dislocated hip an average of 18 months ago. Two patients were slightly improved and five patients were significantly worse after the open reductions. Serious complications related to the surgery ensued in half of the cases. The cost of the surgery and treatment of the complications in these 11 patients was $400,000. We concluded that surgical treatment of paralytic hip dislocations in ambulatory myelomeningocele patients offered no clear cut benefit.

Child↗
PubMed1986

Hydrocephalus, cervical cord lesions, and spinal deformity.

Twenty-six children (4-16 years) had hydrocephalus and spinal deformity; 22 children had scoliosis over 50 degrees, and five children had kyphosis over 100 degrees. Twenty-one children had metrizamide enhanced cord CT scans, and 12 had additional head scans. Two children died, and one was autopsied. Three children had intracranial pressures monitored during spinal surgery. All children had Type I and II Arnold-Chiari malformations, 58% had cord cavitation (syringo/hydromyelia), 67% had cord tethering. The anatomic study showed extensive fibrosis and scarring of the upper cord and brain stem, but intraoperative studies showed that there is free transmission of fluid pressure wave from the cord across the foramen magnum with a consequent rise in intracranial pressure. This study documents frequent coexistence of spinal deformity and central nervous system lesions (hydrocephalus, Arnold-Chiari malformation, cord tethering with atresia, and cord cavitation). It supports the theory that the Arnold-Chiari malformation is a primary developmental deformity and that cord cavitation noted in these patients is primarily syringomyelia formed on the basis of ischemic necrosis within the cord. The free transmission of a fluid pressure wave from the cord to the lateral ventricle supports the Williams theory of propagation of syringomyelic cavities once they have developed. It is conjectural but likely that the CNS lesions cause spinal deformity by disrupting coordinating control of spinal musculature by the normal postural reflex mechanisms. Hydrocephalic patients who develop spinal deformity require thorough investigation for CNS lesions with head scans, CT scans, and metrizamide enhanced CT scans. NMR technology, however, may supplant techniques currently employed.

Adolescent↗
PubMed1979

Internal fixation versus nontreatment of hip fractures in senile patients.

Institutionalized senile patients with hip fractures have a high mortality regardless of whether treatment consists of internal stabilization or is non-operative. In an effort to select the best therapeutic approach in this type of patient, 150 patients were examined in 3 comparable groups. In the first group of 50 patients treatment consisted of surgical stabilization of the fracture. In the second group of 45 patients treatment was non-operative; mortality in these 2 groups was over 50% at the end of 16 weeks. In an effort to improve this degree of risk we transferred 53 patients from the psychiatric hospital to a general hospital for prompt internal stabilization of the hip fractures. There was a striking decrease in mortality to 28% in the third group. We have concluded that under optimal conditions, prompt surgical stabilization of hip fractures in elderly senile individuals offers them the best opportunity of surviving the injury and is preferable to nontreatment.

Aged↗
PubMed1979

Kyphectomy in myelodysplasia.

The techniques used and results obtained in the surgical treatment of the kyphotic deformities of fourteen patients with paraplegia and myelomeningocele are presented. The best results were obtained by vertebral resection at the apex of the deformity, wiring together the facing vertebrae to promote interbody fusion, and correction and maintenance of the realignment with a Harrington distraction rod.

Child↗
PubMed1978

Vertebra plana and eosinophilic granuloma of the cervical spine in children.

Eosinophilic granuloma of the cervical spine in children is a rare lesion which presents both diagnostic and therapeutic problems. The report describes three additional cases. Open biopsy is recommended instead of attempted needle aspiration in children. Laminectomy is likely to result in spinal deformity, and is not advised unless a second stage fusion is planned. Radiotherapy is effective in controlling the lesion. The ultimate outcome is usually good.

Adolescent↗
PubMed1978

Fractures of the odontoid process in young children.

We reviewed eleven patients less than seven years old with fractures of the odontoid process in an effort to establish a more standard form of treatment for the injury and to determine what complications, if any, occur as a result of fractures of the odontoid process in pediatric patients. Our study showed that children with odontoid fractures that are recognized and treated promptly usually do well. The fracture can usually be reduced by passive manipulation or by the "hanging head technique". Support in the reduced position for two to three months in a Minerva jacket or halo cast should be long enough to permit healing. Our study suggests that fractures of the odontoid process in young patients almost always heal.

Age Factors↗