PubMed Health⌕ Search

Biomedical subjects

J W Frymoyer

Publications and source records attributed to J W Frymoyer.

At least 19 recordsLinked to original sources
PubMed1992

Lumbar disk disease: epidemiology.

Sciatica is a common symptom that affects as many as 40% of the adult population at some time. However, clinically significant sciatica is much less common and occurs in only 4% to 6% of the population. Exactly how often the symptom is caused by lumbar disk herniation is uncertain; it is known that herniation can occur independent of symptoms. Among the factors associated with its occurrence are age, gender, occupation, cigarette smoking, and exposure to vehicular vibration. The contribution of other factors such as height, weight, and genetics is less certain. The majority of patients with sciatica appear to recover. Approximately 20% of patients with sciatica caused by lumbar herniation have a strong indication for surgical intervention. In the remainder, indications are based primarily on pain rather than functionally significant neurologic deficits. Because pain is the principle indication, there are wide variations in the rates of surgical intervention between countries, and, even within countries, there are significant regional variations. These variations appear to be driven less by specific medical factors and more by gender, occupation, income, education, and the surgeon's preference. Although the contribution of sciatica to low back pain disability remains uncertain, disability caused by low back pain and sciatica appears to be increasing at a rate disproportionate to population growth. To what degree surgery now contributes to that disability is uncertain, but limited information suggests that it may be substantial.

Adult↗
PubMed1992

Predicting disability from low back pain.

Since World War II, the incidence of chronic low back disability has increased dramatically, at a rate disproportionate to all other health conditions. The factors that contribute to this disability are reviewed. Psychosocial and work environmental factors are far more accurate predictors of disability than physical factors. A predictive risk model is described that allows an estimate of the patient's risk of becoming chronically disabled early in the course of a low back pain episode. This model demonstrates that work environment, perception of compensability, and the duration of the current episode are significantly predictors. Surprisingly, psychologic factors, as measured by the Minnesota Multiphasic Personality Inventory (MMPI), are not predictive in the cohorts studied to date. Although there are inherent limitations in study design, the results offer additional credence to the hypothesis that low back pain disability is often the result of psychosocial and work environmental factors. The model may also be used to address the hypothesis that patients at risk for future disability are more effectively treated by early, aggressive rehabilitation programs.

Back Pain↗
PubMed1992

Diagnosing instability.

The various definitions of instability are reviewed and preference is given to the definition of instability as a loss of stiffness. This definition fits with current laboratory observations. Roentgenographic changes, particularly those associated with degeneration, have no relationship to instability. Multiple roentgenographic images can be of use, but accuracy is limited, and often valuable information at midmotion range or in other planes is missing. Stereoroentgenography appears to offer some promise, but implanted metallic markers are necessary to attain adequate accuracy. Ionizing radiation dose levels are of concern in these techniques. External fixation techniques appear to be of use in some patients. Kinematic linkages and frames containing infrared light emitting diodes are extremely promising, because they give kinematic information in detail.

Humans↗
PubMed1991

Identifying patients at risk of becoming disabled because of low-back pain. The Vermont Rehabilitation Engineering Center predictive model.

A predictive risk model of low-back pain (LBP) disability was developed by a panel of six experts in the fields of chronic pain and disability. It comprised 28 factors organized into eight categories: job, psychosocial, injury, diagnostic, demographic, medical history, health behaviors, and anthropometric characteristics and was administered as a 15-minute written questionnaire. The model was tested prospectively on 250 patients (age range, 18-65 years) attending two secondary-care low-back clinics. Disability, as predicted by the model, was compared with 1) actual disability assessed 3 and 6 months later; 2) predictions of disability made by the attending physicians; and 3) predictions obtained from an empirically derived model. These results showed that 1) the expert-generated risk model had a predictive accuracy of 89% and did better in predicting disability than the physicians across all samples and 2) the empirically weighted model did best of all (91% predictive accuracy), suggesting that the expert model used appropriate factors but that the weights assigned to these factors by the panel of experts could be improved.

Adult↗
PubMed1991

Clinical tests applicable to the study of chronic low-back disability.

This symposium has evaluated the possible directions to be taken in designing reliable and valid questionnaires, screening examinations, and paraclinical tests applicable to studies in LBP. The detailed design of such test instruments, field testing, measures of reliability, and validity represent the next step if the current barriers to collaborative clinical research in LBP are to be overcome.

Back Pain↗
PubMed1991

An overview of the incidences and costs of low back pain.

The basic premise of this article is that low back disorders are extremely prevalent in all societies, and probably have not increased substantially over the past two decades. What has increased is the rate of disability, the reasons for which are uncertain. Not only has this phenomenon heightened the awareness of low back pain, but it has led to an explosion in costs. Although a precise estimate is impossible, it is plausible that the direct medical and indirect costs of these conditions are in the range of more than $50 billion per annum, and could be as high as $100 billion at the extreme. Of these costs, 75% or more can be attributed to the 5% of people who become disabled temporarily or permanently from back pain--a phenomenon that seems more rooted in psychosocial rather than disease determinants. Within this overall equation, spinal surgery plays a relatively small role, although the contribution to disability probably has more than passing significance. The future challenge, if costs are to be controlled, appears to lie squarely with prevention and optimum management of disability, rather than perpetrating a myth that low back pain is a serious health disorder.

Back Pain↗
PubMed1991

Low back pain. The role of spine fusion.

The major objectives of spinal surgery are to relieve pain, improve function, and correct deformity. The surgical strategies to meet these objectives are decompression of neural elements or surgical stabilization by arthrodesis. This article analyzes spinal fusion from the perspective of indications, the broad principles of surgical technique, the results that can be obtained, and the complications of the procedure.

Back Pain↗
PubMed1979

Rheumatic syndromes in endocrine disease.

It is not widely appreciated that endocrine disease may present primarily as rheumatic syndromes, sometimes spectacular in onset, more commonly insidious and subtle, making their true recognition difficult. The underlying hormonal, biochemical, and metabolic events have understandable reflection in the structure and function of bone, joint, and muscle.

Acromegaly↗
PubMed1978

The role of trauma in low back pain: a review.

Trauma plays an important role in the production of low back pain. This review emphasizes how the forces to which the spine is subjected are modified by many factors. Attention is directed to the role of mechanical stress in the etiology of spondylolisthesis, subtle spinal fractures, as well as the relevance of stress to the degenerative process. It is suggested that trauma plays a very major role in low back pain but, at present, the problems in diagnostic technology create difficulty in establishing the precise degree of that role. The drawbacks of over-reliance on plane radiography are emphasized. It is suggested that improved diagnostic techniques may result in more accurate treatment and perhaps less disability resultant from the ubiquitous problem of low back pain.

Back Pain↗
PubMed1978

Disc excision and spine fusion in the management of lumbar disc disease. A minimum ten-year followup.

Seventy-nine percent of 312 patients who underwent lumbar disc surgery were evaluated at least 10 years postoperatively (mean equal to 13.7 years). Residual back and nerve root symptoms and functional impairment were equally as common among the 143 patients who underwent fusion as they were among the 64 patients who did not. Thirty percent of the patients whose spines were fused and 37.7% of those patients whose spines were not fused were considered long-term failures because of persistent symptoms or the need for reoperation. Thirty-seven percent of the fusion patients had persistent graft donor site symptoms. Examined patients showed a high percentage of residual neurologic defects. An unexplained positive Trendelenburg sign was present in 14.8% of the fusion patients and in 18.2% of the patients whose spines were not fused. Although retrospective studies often have problems of accuracy, this analysis confirms other observations that midline spinal fusion offers few benefits in the management of lumbar disc disease.

Adult↗
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↗
PubMed1977

Fracture healing in the sciatically denervated rat.

Fractures of the fibula were produced in rats with sciatic denervation. The denervated rats exhibited more rapid fracture healing than controls. Fifteen days following injury, enhanced union was measured by histologic assessment (p less than 0.001), and biomechanical testing including fracture stress (p less than 0.005), elastic modulus (p less than 0.005), strain at failure (p = 0.01) and energy to failure (p = 0.05).

Animals↗
PubMed1977

Adult-onset vitamin D-resistant hypophosphatemic osteomalacia. A possible variant of vitamin D-resistant rickets.

A family of 133 members showing unusual manifestations of vitamin D-resistant hypophosphatemic osteomalacia was studied. The hypophosphatemic children did not have rickets or clinical femoral bowing: the hypophosphatemic young adults had minimum clinically evident femoral bowing; and the older adults (age forty and older) were progressively disabled by severe bowing. The disorder appears to be an X-linked dominant, with almost complete penetrance of the hypophosphatemic trait. The etiology of this disorder could not be determined.

Adolescent↗