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Biomedical subjects

K F Spratt

Publications and source records attributed to K F Spratt.

At least 37 records · Page 2Linked to original sources
PubMed1996

Muscular response to sudden load. A tool to evaluate fatigue and rehabilitation.

STUDY DESIGN: Subjects were exposed to fatiguing and restorative interventions to assess their response to sudden loads. OBJECTIVES: To investigate the erector spinae and rectus abdominis response characteristics to "sudden load" and the effect of fatigue and rehabilitation. SUMMARY OF BACKGROUND DATA: Unexpected loads which people often experience, can lead to high forces in the spine and may be a cause of low back injury. METHODS: Muscle responses to sudden load were mediated by fatigue, walking, expectation, method of load application, exposure to vibration, and cognitive-behavioral rehabilitation in patients with chronic low back pain. A novel technique, perfected in this work, called wavelet analysis, was used to analyze these data. RESULTS: Reaction time was affected by fatigue and expectation. Vibration exposure significantly increased the muscle response time. Walking was able to ameliorate that effect. Back muscles responded differently, depending on whether loads were applied to the back through the hands or through the trunk. Electromyographic reaction time and magnitude decreased in patients after a 2-week rehabilitation program. CONCLUSIONS: Sudden loads can exacerbate fatigue effects. Walking after driving reduces the risk to the back caused by handling unpredictable loads. Vibration exposure guidelines should be more conservative. Patients have longer response times than healthy subjects, but patients can improve their response to sudden loads via rehabilitation. Patients exhibit a flexion-extension oscillation at 5 Hz in response to a sudden load, suggesting that the 5-Hz, seated, natural frequency observed during whole-body vibration may result from neurophysiologic control limits.

Adult↗
PubMed1996

Hyperextension and spine height changes.

STUDY DESIGN: The effect on spine height changes from different combinations of time and angle of static prone hyperextension, and one intervention of dynamic hyperextension was explored. OBJECTIVES: To explore whether controlled hyperextension would cause an height increase with greater duration than previously shown, and to find an optimal combination of hyperextension angle and duration of the intervention. SUMMARY OF BACKGROUND DATA: Hyperextension is a METHODS: Ten subjects were exposed to hyperextension in the prone position for different time periods and with different amounts of hyperextension. The effect was measured using the stadiometer for measurement of spine height changes. RESULTS: The study showed that time was the most important variable, and also that for a given time, there was an increased recovery with increased angle. CONCLUSIONS: The results indicate that hyperextension can be a beneficial maneuver to unload temporarily the spine after loading and to rehydrate the discs, providing enough time is given for the procedure. The optimal time and angle combination was 20 degrees for 20 minutes because this intervention resulted in the largest recovery that lasted for a relatively long period of time.

Adult↗
PubMed1995

1995 Volvo Award in clinical sciences. The diagnostic accuracy of magnetic resonance imaging, work perception, and psychosocial factors in identifying symptomatic disc herniations.

STUDY DESIGN: This was a prospective study of patients (study group) with symptomatic disc herniations and asymptomatic volunteers (control group) matched for age, sex, and work-related risk factors. OBJECTIVE: To determine the prevalence of disc herniation in a matched group of asymptomatic volunteers and to access the diagnostic accuracy of magnetic resonance imaging, work perception, and psychosocial factors in identifying symptomatic disc herniations. SUMMARY OF BACKGROUND DATA: Disc herniations have been reported to occur in 20-36% of asymptomatic volunteers. A valid comparison of asymptomatic individuals and patients with disc herniations has not been performed. METHODS: Forty-six patients with low back pain and sciatica severe enough to require a discectomy were compared with 46 age-, sex-, and risk factor-matched (heavy lifting, twisting and bending, vibration, and sedentary activity) asymptomatic volunteers. Both groups had a complete clinical and magnetic resonance imaging examination and completed a questionnaire to assess differences in the psychosocial and work perception profiles. The prevalence and the severity of morphologic alterations (disc herniation, disc degeneration, and neural compromise) was analyzed by tow independent radiologists in a blinded fashion. Differences between both groups regarding MRI findings, work perception (occupational mental stress, intensity of concentration, job satisfaction, and job-related resignation) and psychosocial factors (anxiety, depression, self-control, social support, and marital status) were compared using multivariate techniques. Stepwise discriminating analysis was used to identify the best discriminating variables within the magnetic resonance image, work perception, and psychosocial categories in terms of the diagnostic accuracy to predict group membership (study [pain] or control [no pain] group). RESULTS: Matched controls had significantly more risk factors than a group of normal individuals. The present study has presented evidence that an age-, gender-, and occupational risk factors-matched group of asymptomatic patients shows a high incidence rate of disc herniations (76%). Although significantly less than the symptomatic group incidence of 96%, this represents a much higher prevalence rate than generally expected and reported in other studies of unmatched asymptomatic volunteers. Patients had more severe disc herniations (disc extrusions) than asymptomatic volunteers (35% vs. 13%). There was no significant differences regarding disc degeneration between both groups (96% vs. 85%). The only substantial morphologic difference between both groups was the presence of a neural compromise (83% vs. 22%), which was highly significant (P < 0.0001). There were significant differences between both groups regarding work perception (occupational mental stress, intensity of concentration, job satisfaction, and resignation; P < 0.027) and psychosocial factors (anxiety, depression, self-control, marital status; P < 0.0001). The best single predictor of a group membership was the extent of neural compromise. A combination of this factor with occupational mental stress, depression, and marital status was the best predictive model. With this model, the false-negative rate (potential overtreatment of disc morphology) was reduced by more than half compared with morphologic factors (nerve root compression) alone (22% vs. 11%). CONCLUSIONS: In an age-, sex-, and risk factor-matched group of asymptomatic individuals, disc herniation had a substantially higher prevalence (76%) than previously reported in an unmatched group. Individuals with minor disc herniations (i.e., protrusion, contained discs) are at a very high risk that their magnetic resonance images are not a causal explanation of pain because a high rate of asymptomatic subjects (63%) had comparable morphologic findings. The only highly significant difference between the study group and control group regarding morphologic fi

Adult↗
PubMed1995

Long-term follow-up of patients with chronic back pain treated in a multidisciplinary rehabilitation program.

STUDY DESIGN: The study evaluated the long-term outcomes of 129 chronic low back pain patients who had completed a multidisciplinary rehabilitation program. OBJECTIVES: Two major outcome issues were addressed--one related to the effectiveness of the program as measured by return to work, use of the medical system, and sense of well being, and the other concerning the stability of the outcome effect over time. SUMMARY OF BACKGROUND DATA: Other outcome studies have established the short-term effectiveness of rehabilitation programs such as the present one with between 50% and 75% of patients. However, long-term follow-up--i.e., 1 1/2 to 2 years or more--has been lacking to determine what happens later. METHODS: Graduates of the program were contacted by telephone to complete a 23-item questionnaire. Every effort was made to include all who had completed the program. Many had moved away or were inaccessible, but few of those contacted refused to participate. RESULTS: An attempt was made to classify the job outcome into good, fair, and poor outcomes by weighting return to work, remaining at work, and continuing to look for work. Forty-nine percent of the sample attained a good job outcome, 13% a fair job outcome, and 38% a poor job outcome. Regarding general well-being, 53% reported doing better or much better, 27% reported being about the same, and 20% reported being worse or much worse at follow-up. CONCLUSIONS: The results provide support for the efficacy of programs such as this.

Adult↗
PubMed1994

Outcome measures for studying patients with low back pain.

There is growing recognition in the treatment of back pain that patient perspectives are essential in judging the results of treatment. Improving the patient's "quality of life" is often the main goal of therapy. Thus, although clinical research in the past has focused on physiologic outcomes, such as range of motion, muscle strength, or neurologic deficits, increasing attention is being given to the rigorous measurement of symptoms, functional status, role function, satisfaction with treatment, and health care costs. In many cases, these so-called "soft" outcomes can be measured with a level of reproducibility similar to more conventional clinical data such as imaging test results. Because symptoms and functional outcomes are sometimes only loosely associated with physiologic phenomena, the former outcomes should be measured directly. Modern questionnaires for measuring patient quality of life combine the expertise of social scientists and clinicians and have demonstrated validity. Furthermore, they have some important advantages over simple ratings of "excellent, good, fair, and poor" outcomes, or work status alone. Several modern instruments for measuring health-related quality of life in patients with low back pain are reviewed briefly, describing their content and length. Wider use of these instruments would help to increase clinician familiarity with their meaning and avoid duplication of effort in questionnaire development.

Health Status Indicators↗
PubMed1994

Strategies for outcome research in spinal disorders. An introduction.

The evaluation of the clinical utility of the clinical diagnostic tests and procedures, what works in spinal disorders, and for whom and how treatment affects a patient's symptoms and function are key questions of outcomes research. This paper describes the advantages and limitations of the main study approaches used. Examples from the spine literature on spinal stenosis are used for illustration.

Female↗
PubMed1994

Experimental lumbar radiculopathy. Immunohistochemical and quantitative demonstrations of pain induced by lumbar nerve root irritation of the rat.

OBJECTIVE: A series of experiments were designed to develop and validate an animal model of lumbar radiculopathy. More specifically, these investigations introduced a model of chronic neuropathic pain in the rat associated with clinically relevant lumbar nerve root trauma and evaluated the ability of the model to effect symptoms and begin to understand the underlying neurochemical and neurophysiologic factors associated with these neurologic abnormalities. SUMMARY OF BACKGROUND DATA: A search of the literature suggested that these studies were a first attempt to distinguish and elucidate an experimental lumbar radiculopathy. METHODS: Two basic approaches to nerve trauma were considered, direct damage to the nerve via compression, and introduction of foreign materials in proximity to the nerve root that might cause irritation and inflammation leading to chronic symptoms. Ligature around the nerve (i.e., surrounding the nerve with a suture) was considered a plausible irritant that might behave in an animal model in a similar way that nerve root entrapment, often observed in HNP and stenosis cases, might function in humans. Further, varying levels of irritation was modeled by using 4-0 silk as a mild and 4-0 chromic gut as a more harsh irritant. STUDY DESIGN: Five distinct treatments of the nerve roots were investigated initially: 1) a sham intervention, where the surgery simply exposed the nerve roots and dorsal root ganglion followed by standard closing procedures; 2) nerve root clipping, where the nerve roots were clipped with a microhemoclip; 3) 4-0 silk ligature, where two loose ligatures of 4-0 silk were placed around the nerve roots; 4) 4-0 chromic gut 1, where one loose ligature of 4-0 chromic gut was placed around the nerve roots; and 5) 4-0 chromic gut 2, where four 0.3 cm pieces of 4-0 chromic gut were laid adjacent to the nerve roots and secured by two loose ligatures of 4-0 chromic gut. ANOVA techniques were used to test for differential effects across time for the five treatment groups in terms of animal function and biochemistry in the DRG. RESULTS: Rats treated with chromic gut ligature in large quantity demonstrated differential patterns of results on the injured and noninjured sides consistent with a lumbar radiculopathy. The injured side demonstrated significantly worse thermal hyperalgesia related to neuropathic pain (P < 0.0001); initial mechanical hypoalgesia (P < .001), and motor dysfunction (P < .001) resolving within 2 weeks; significantly increased c-fos counts (P < .0001) 2 weeks postoperatively, which showed a consistent trend toward baseline and return to baseline by 12 weeks; significantly greater and highly increased VIP concentrations in the dorsal root ganglia 2 weeks postoperatively (P < .0001) that did not resolve or tend towards baseline after 12 weeks of follow-up in conjunction with a trend toward VIP depletion in the spinal cord 2 weeks postoperatively that did resolve to baseline until a 12-week concentration indicated a significant increase in concentration (P < .002). Quantitative and qualitative changes in c-fos and VIP, correlated with the patterns of behavior and function. Thus, for the first time, evidence to link outcome behaviors and function with underlying neurochemical processes is suggested. CONCLUSIONS: When the same apparent conditions can be demonstrated in some situations to be causing pain and in other situations to be independent of pain, some additional factor or factors not considered in the original investigations may be mediating the outcome. Neurochemical consequences of nerve root irritation provide a theoretical framework for hypothesizing about various types of mediating events that might explain how similar apparent pathology might reasonably lead to different predictions about behavior consequences of the pathology.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Experimental lumbar radiculopathy. Behavioral and histologic changes in a model of radicular pain after spinal nerve root irritation with chromic gut ligatures in the rat.

OBJECTIVE: The recently proposed animal model of lumbar radiculopathy was used to investigate behavioral consequences and histologic changes in spinal nerve roots, dorsal root ganglia, and spinal nerves after the L4, L5, and L6 nerve roots were loosely ligated with either silk or chromic gut sutures in an attempt to better understand the pathophysiologic mechanisms that give rise to pain associated with lumbar radiculopathy. SUMMARY OF BACKGROUND DATA: Little is known about the pathophysiologic mechanisms that give rise to pain associated with lumbar radiculopathy. The recently proposed animal model of unilateral lumbar radiculopathy, which demonstrated an association with motor paresis and thermal hyperalgesia of the affected hind limb and showed evidence of spontaneous pain has been demonstrated, may serve as a vehicle to allow direct investigation of the nature of the pathophysiological mechanisms associated with lumbar radiculopathy. METHODS: Three distinct treatments of the nerve roots were initially investigated: 1) a sham intervention, where the surgery simply exposed the nerve roots and dorsal root ganglion followed by standard closing procedures; 2) 4-0 silk ligature, where two loose ligatures of 4-0 silk were placed around the nerve roots; and 3) 4-0 chromic gut 2, where four 0.3 cm pieces of 4-0 chromic gut were laid adjacent to the nerve roots and secured by two loose ligatures of 4-0 chromic gut. STUDY DESIGN: ANOVA techniques were used to test for differential effects across time for the three treatment groups in terms of animal function. A qualitative analysis of the histology of the ipsilateral and contralateral nerve roots, dorsal root ganglia, and spinal nerves was done to correlate histologic changes with behavioral changes. RESULTS: Behavioral results were consistent with the previous study. Rats treated with chromic gut, but not silk, reliably demonstrated a prolonged thermal hyperalgesia that was maximal 2 weeks after surgery and lasted for up to 12 weeks. These behavioral changes, however, were not correlated with histologic changes in myelinated fiber content in the L4, L5, and L6 nerve roots, dorsal root ganglia and spinal nerves, the ipsilateral spinal nerved, dorsal root ganglia, and nerve roots of rates ligated with silk or chromic gut showed similar, significant, decreased in the number of large diameter myelinated fibers. CONCLUSIONS: These results suggest that mechanical constriction of the L4, L5, and L6 spinal nerve roots, as evidenced by a loss of myelinated fibers, is not sufficient to produce the behavioral effects associated with this model of lumbar radiculopathy. It is hypothesized that chemical factors from the chromic gut play a role in the pathophysiology and development of the behavioral, but not histological, changes in this model of lumbar radiculopathy.

Animals↗
PubMed1993

Efficacy of flexion and extension treatments incorporating braces for low-back pain patients with retrodisplacement, spondylolisthesis, or normal sagittal translation.

Radiographic instability seemingly enjoys the status of a well-defined clinical syndrome. The concept is widely used, and specific treatments, usually spinal fusion, are routinely performed based on the diagnosis. The minimum standards necessary to establish radiographic instability as a legitimate clinical syndrome have not been established, however. The primary purpose of this study was to determine if treatment involving bracing, exercise, and education controlling either flexion or extension postures, would result in a distinctive pattern of favorable or unfavorable results, depending on the type of radiographic instability (retrodisplacement or spondylolisthesis). Fifty-six patients meeting strict study inclusion and radiographic evaluation criteria were assigned signed to a bracing treatment (flexion, extension, placebo-control) according to a randomization scheme, designed to ensure equal representation of translation categories (retro, normal, spondy) across treatment groups, and assessed at admission and 1-month follow-up. The sample was relatively evenly divided between men (46%) and women (54%), and by age. Translation classification was related to both gender and age, with men more likely classified as retro and women more likely spondy and patients in their 20s having lower incidence of spondy and higher incidence of normal translation. Translation classification was not related to selected indices of low-back pain history. Brace treatments were not shown to reduce patient range of motion or lessen trunk strength. A significant treatment by time interaction for the modified pain interference (VAS) scale indicated improvement for patients in extension compared with patients in flexion and control-placebo treatments. In conjunction with no significant three-way interaction between treatment, translation classification, and time, it was hypothesized that radiographic instability might more appropriately be considered a corroborative sign of advanced discogenic problems. Improvement in extension treatment, regardless of the type of radiographic abnormality, suggests that the treating clinician might consider extension treatment for chronic low-back pain patients. Causes and implications for the failure of this study to provide support for considering radiographic instability as a clinical syndrome are considered and future directions for this area of research suggested.

Adult↗
PubMed1993

Predicting long-term disability in low back injured workers presenting to a spine consultant.

Low back pain (LBP) is the most common, costly, and disabling musculoskeletal condition. Although most LBP patients recover within two months, 2-3% eventually develop disabling chronic low back pain (DCLBP). Due to the prevalence of DCLBP problems, models have been developed to predict which acute low back pain patients are predisposed to the problems associated with this condition. Many see the development of these models as a first step that must be taken before useful approaches for containing and reducing the problem can be conceptualized, implemented, and tested. A recent publication by Cats-Baril and Frymoyer considered this specific problem. While the results of their study indicate considerable success in predicting DCLBP patients, the high prediction rates they obtained may be spurious because of the characteristics of their sampled patient population in conjunction with some of the predictors they found useful in identifying DCLBP patients. The purpose of the present study was to focus on the crucial patient population (i.e., acute LBP patients who perceive their problem as work-related and who have been unable to work for more than two but less than six weeks), and evaluate the ability of various personal, medical, occupational, and psychological factors to predict predisposition to DCLBP. Fifty-five patients referred by occupational physicians were evaluated and followed successfully for at least 6 months. Patients in the study were given a physical examination that included Spratt et al's assessment of pain behavior. They were then asked to fill out an extensive battery of self-report questionnaires, addressing issues associated with personal demographics, health history, work requirements, job satisfaction, injury information, and pain/function factors. At the 6-month follow-up, a structured telephone interview was used to obtain outcome information regarding patient status, including ability to return to work and general outcomes of treatment. Average patient age was 37.2 years (range, 22-57) and 67% of the patients were male. On average, patients had been unable to work for approximately 4 weeks when initially surveyed. Overall, 12.7% of the patients returned to work within 1 month of injury, 40% returned within 2 months, 54.5% within 3 months, 69% within 4 months, 74.5% within 5 months, 76.3% within 6 months, 80% within 7 months, and 83.6% after 7 months. Approximately 16% never successfully returned to work within the follow-up period of this study. DCLBP was found to be correlated only with marital status, as married patients returned to work more quickly than single patients (P < 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

Thoracolumbar burst fractures. The clinical efficacy and outcome of nonoperative management.

There continues to be considerable controversy regarding the management of thoracolumbar burst fractures. Most feel that failure of the middle osteoligamentous complex, particularly with retropulsion of fragments into the spinal canal, is an indication for operative management. Others advocate postural reduction and prolonged bedrest for such injuries. The purpose of this study was to 1) review the clinical outcome and efficacy of closed management of thoracolumbar burst fractures; and 2) quantify what, if any, remodeling occurs in the bony canal as measured by serial CT. Forty-one patients who presented with a burst fracture of the thoracolumbar spine without neurologic deficit were reviewed clinically and radiographically following nonoperative management. At injury, canal compromise averaged 37% (range, 16-66%); 26 patients had at least 30% canal compromise. During treatment, one patient developed neurologic deterioration that prompted surgery; all other patients remained neurologically intact. At average follow-up of 2 years, an overall outcome evaluation indicated that 49% of the patients had excellent outcomes relative to pain and function; 17%, good; 22%, fair; and 12%, poor. Approximately 90% of the patients had a satisfactory work status relative to factors associated with their burst fracture. Serial roentgenograms documented significant progression in body collapse, which averaged 8% (P < 0.0001) from injury to follow-up. On the other hand, serial CTs documented significant improvement from injury to follow-up for canal compromise and midsagittal diameter. Average improvements in canal compromise and midsagittal diameter were 22% (P < 0.0001) and 11% (P < 0.0001), respectively. Only three patients had canal compromise greater than 30%, no patients had canal compromise greater than 40%, and no patients experienced canal area deterioration over time. On average, nearly two-thirds of the fragment occluding the canal resorbed, with most remodeling complete within one year. For patients with burst fractures presenting neurologically intact, we obtained the following findings: 1) nonoperative management yields acceptable results; 2) following nonoperative management, bony deformity (i.e., kyphosis and body collapse) progresses marginally relative to the rate of canal area remodeling; 3) incidence of subsequent neurologic deficits is quite low; and 4) initial radiographic severity of injury or residual deformity following closed management does not correlate with symptoms at follow-up. This pattern of results suggests nonoperative management as the preferred treatment in these circumstances.

Adult↗
PubMed1993

The natural history and long-term follow-up of Scheuermann kyphosis.

Sixty-seven patients who had a diagnosis of Scheuermann kyphosis and a mean angle of kyphosis of 71 degrees were evaluated after an average follow-up of thirty-two years (range, ten to forty-eight years) after the diagnosis. All sixty-seven patients completed a questionnaire; fifty-four had a physical examination and radiographs; fifty-two, pulmonary function testing; and forty-five, strength-testing of the trunk muscles. The results were compared with those in a control group of thirty-four subjects who were matched for age and sex. The patients who had Scheuermann kyphosis had more intense back pain, jobs that tended to have lower requirements for activity, less range of motion of extension of the trunk and less-strong extension of the trunk, and different localization of the pain. No significant differences between the patients and the control subjects were demonstrated for level of education, number of days absent from work because of low-back pain, extent that the pain interfered with activities of daily living, presence of numbness in the lower extremities, self-consciousness, self-esteem, social limitations, use of medication for back pain, or level of recreational activities. Also, the patients reported little preoccupation with their physical appearance. Normal or above-normal averages for pulmonary function were found in patients in whom the kyphosis was less than 100 degrees. Patients in whom the kyphosis was more than 100 degrees and the apex of the curve was in the first to eighth thoracic segments had restrictive lung disease. Five patients had an unexplained, mildly abnormal neurological examination. Mild scoliosis was common; spondylolisthesis was not observed.

Activities of Daily Living↗
PubMed1992

Isolated L4-L5 fusions using the variable screw placement system: unilateral versus bilateral.

Thirty-six patients were retrospectively followed an average of 25.1 months to evaluate the relative effectiveness of unilateral (16 patients) versus bilateral (20 patients) variable screw placement (VSP) instrumentation in isolate L4-L5 fusions. Demographic variables and preoperative diagnoses were similar between treatment groups. Outcome was assessed primarily through evaluation of plain roentgenograms and self-report questionnaires. Use of VSP instrumentation at the L4-L5 level with autogenous posterolateral grafting achieved a successful fusion rate of 97% with minimal complications. Fusion results with unilateral instrumentation were nearly identical to those of bilateral; in both cases, results were better than most historical controls for noninstrumented fusions in situ. Clinical outcome, as obtained through standardized measurement techniques of pain and function, demonstrated 69% excellent and good results. Clinical outcome was similar between treatment groups yet was not significantly related to the fusion status obtained at follow-up.

Adult↗
PubMed1990

A new approach to the low-back physical examination. Behavioral assessment of mechanical signs.

UNLABELLED: A rationale for a new approach to the low-back physical examination was developed. A set of 21 tests, 17 assessing organic and four assessing nonorganic signs, were organized into an examination according to specified criteria, and the reliability of the patient-reported and examiner-observed measures within the examination assessed. Primary outcome measures included patient reports of their pain location, aggravation and examiner-observed pain behaviors resulting from the maneuvers. Two pain behavior composites, conceptualized as outcome measures, were developed, one based on the 17 organic tests and one based on the four nonorganic tests. DESIGN: The reliability of the physical examination was assessed using a short-term test-retest paradigm. Three raters, two experienced orthopaedic surgeons and an RN with no previous experience in administering physical examinations were trained in the examination methods. Patients were assigned to one of three rater pairs and examined twice within a single day. During each examination both raters evaluated each patient; however, rater role as examiner or observer was reversed across examination. RESULTS: Forty-two patients were examined. Average times of 13.9 and 11.6 minutes were required to complete examinations 1 and 2, respectively. In addition, the time required to complete the examination decreased as the examiners became more familiar with the procedure, suggesting that an experienced examiner would usually be able to complete the examination in approximately 10 minutes. Within-examination reliabilities for the patient-reported measures (pain location and aggravation) were universally high, as expected, since these rating required the rater only to correctly hear and code patient responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Back Pain↗