WITHDRAWN: Lumbar supports for prevention and treatment of low-back pain.

BACKGROUND: Lumbar supports are used in the treatment of low back pain patients to make the impairment and disability vanish or decrease. Lumbar supports are also used to prevent the onset of low back pain (primary prevention) or to prevent recurrences of a low back pain episode (secondary prevention). OBJECTIVES: The objective of this systematic review was to assess the effects of lumbar supports for prevention and treatment of non-specific low back pain. SEARCH STRATEGY: We searched the Medline, Cinahl and Current Contents databases and the Cochrane Controlled Trials Register up to September 1999, and the Embase database up to September 1998. We also screened references given in relevant reviews and identified controlled trials, and used Science Citation Index to identify additional controlled trials. SELECTION CRITERIA: Controlled clinical trials that reported on any type of lumbar supports as preventive or therapeutic intervention for non-specific low back pain were included. DATA COLLECTION AND ANALYSIS: One author extracted data from the trials considering characteristics of the study population, characteristics of the interventions and the final results for each outcome measure. The author compared these findings to data regarding the same characteristics of the same studies published already in other reviews. The methodological quality was independently assessed by two authors. Because it was not possible to perform a quantitative analysis, a qualitative meta-analysis was performed in which the strength of evidence on the effectiveness of lumbar supports was classified as being strong, moderate, limited or conflicting, and no evidence. MAIN RESULTS: Five randomized and two nonrandomized controlled preventive trials and six randomized therapeutic trials were included in our review. Overall the methodological quality of the studies included in our review was rather low. Only four of the thirteen studies scored positive on 50% or more of the the internal validity items. There was moderate evidence that for primary prevention lumbar supports are not more effective than other types of treatment or no intervention. No evidence was found on the effectiveness of lumbar supports for secondary prevention. The systematic review of therapeutic trials showed that there is limited evidence that lumbar supports are more effective than no treatment, while it is still unclear if lumbar supports are more effective than other interventions for treatment of low back pain. AUTHORS' CONCLUSIONS: There is still a need for high quality randomised trials on the effectiveness of lumbar supports. One of the most essential issues to tackle in these future trials seems to be the realisation of an adequate compliance.

Steindler award lecture. Cross the borders.

The orthopaedic scientists of today, whether a clinician or a basic scientist, must cross both interdisciplinary and national borders to advance the field. Examples derived from the author's own experience of such border crossings are given, mainly as they relate to research in spinal disorders.

Effectiveness of treatment with a brace in girls who have adolescent idiopathic scoliosis. A prospective, controlled study based on data from the Brace Study of the Scoliosis Research Society.

In a prospective study by the Scoliosis Research Society, 286 girls who had adolescent idiopathic scoliosis, a thoracic or thoracolumbar curve of 25 to 35 degrees, and a mean age of twelve years and seven months (range, ten to fifteen years) were followed to determine the effect of treatment with observation only (129 patients), an underarm plastic brace (111 patients), and nighttime surface electrical stimulation (forty-six patients). Thirty-nine patients were lost to follow-up, leaving 247 (86 per cent) who were followed until maturity or who were dropped from the study because of failure of the assigned treatment. The end point of failure of treatment was defined as an increase in the curve of at least 6 degrees, from the time of the first roentgenogram, on two consecutive roentgenograms. As determined with use of this end point, treatment with a brace failed in seventeen of the 111 patients; observation only, in fifty-eight of the 129 patients; and electrical stimulation, in twenty-two of the forty-six patients. According to survivorship analysis, treatment with a brace was associated with a success rate of 74 per cent (95 per cent confidence interval, 52 to 84) at four years; observation only, with a success rate of 34 per cent (95 per cent confidence interval, 16 to 49); and electrical stimulation, with a success rate of 33 per cent (95 per cent confidence interval, 12 to 60).(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of progression of the curve in girls who have adolescent idiopathic scoliosis of moderate severity. Logistic regression analysis based on data from The Brace Study of the Scoliosis Research Society.

In a study conducted by the Scoliosis Research Society, 159 girls with a mean age of thirteen years (range, ten to fifteen years) who had adolescent idiopathic scoliosis were followed prospectively until skeletal maturity or until the curve had increased 6 degrees or more. All patients had had an initial curve of 25 to 35 degrees and an apical level between the eighth thoracic and first lumbar vertebrae, inclusive. Of the 159 patients, 120 were observed without treatment and thirty-nine were managed with lateral electrical surface stimulation. The curve progressed at least 6 degrees in eighty patients. There was no apparent difference in the outcome between the patients who were managed with observation only and those who were given electrical stimulation. Logistic regression analysis was performed to determine which of eleven factors were predictive of progression of the scoliotic curve. A Risser sign of 0 or 1, an apical level cephalad to the twelfth thoracic vertebra, and an imbalance of ten millimeters or less were found to be independently prognostic of progression of more than 6 degrees. A prognostic model that included these three factors and chronological age allowed correct classification of the curve as either progressive or non-progressive in 81 per cent of these patients who had a thoracic or thoracolumbar adolescent idiopathic scoliosis. The positive predictive value was 82 per cent, the negative predictive value was 80 per cent, and the sensitivity and specificity were each 81 per cent.

Results of surgical treatment of adults with idiopathic scoliosis.

The outcome of surgical treatment of idiopathic scoliosis in forty-five adults was studied with special attention to pain, function, self-image, and pulmonary function. All of the patients were more than twenty-five years old at operation and had been followed for more than three years. Every patient who was operated on by one of us (J. E. H.) and who met these criteria was evaluated. The magnitude of the curves averaged 66 degrees. Standardized gradations of pain and function showed improvement over-all, but significant impairment remained. There was a reduction in the levels of peak and constant pain, but no change in the frequency of peak pain after operation. The number of patients who were pain-free after surgery was not increased. Functional impairment due to the scoliosis was lessened, and the ability to perform the common activities of daily living was improved, but no important changes in occupation or recreational activity were recorded. Correlations of pain or function, or both, and the changes in either, were found with only two parameters: age at follow-up and physical occupation. Pulmonary function, as measured, did not change. Eighteen (40 per cent) of the patients had a minor complication and ten (20 per cent), a major complication; there was one death, due to pulmonary embolism, of a patient who was excluded from the series. In view of the high rate of complications, the limited gains to be derived from spinal fusion should be assessed and clearly explained to patients before the procedure is undertaken.

Lumbar supports for prevention and treatment of low back pain.

BACKGROUND: Lumbar supports are used in the treatment of low back pain patients to make the impairment and disability vanish or decrease. Lumbar supports are also used to prevent the onset of low back pain (primary prevention) or to prevent recurrences of a low back pain episode (secondary prevention). OBJECTIVES: The objective of this systematic review was to assess the effects of lumbar supports for prevention and treatment of non-specific low back pain. SEARCH STRATEGY: We searched the Medline, Cinahl and Current Contents databases and the Cochrane Controlled Trials Register up to September 1999, and the Embase database up to September 1998. We also screened references given in relevant reviews and identified controlled trials, and used Science Citation Index to identify additional controlled trials. SELECTION CRITERIA: Controlled clinical trials that reported on any type of lumbar supports as preventive or therapeutic intervention for non-specific low back pain were included. DATA COLLECTION AND ANALYSIS: One reviewer extracted data from the trials considering characteristics of the study population, characteristics of the interventions and the final results for each outcome measure. The reviewer compared these findings to data regarding the same characteristics of the same studies published already in other reviews. The methodological quality was independently assessed by two reviewers. Because it was not possible to perform a quantitative analysis, a qualitative meta-analysis was performed in which the strength of evidence on the effectiveness of lumbar supports was classified as being strong, moderate, limited or conflicting, and no evidence. MAIN RESULTS: Five randomized and two nonrandomized controlled preventive trials and six randomized therapeutic trials were included in our review. Overall the methodological quality of the studies included in our review was rather low. Only four of the thirteen studies scored positive on 50% or more of the the internal validity items. There was moderate evidence that for primary prevention lumbar supports are not more effective than other types of treatment or no intervention. No evidence was found on the effectiveness of lumbar supports for secondary prevention. The systematic review of therapeutic trials showed that there is limited evidence that lumbar supports are more effective than no treatment, while it is still unclear if lumbar supports are more effective than other interventions for treatment of low back pain. REVIEWER'S CONCLUSIONS: There is still a need for high quality randomised trials on the effectiveness of lumbar supports. One of the most essential issues to tackle in these future trials seems to be the realisation of an adequate compliance.

Disc pressure measurements.

By measurement of intradiscal pressure in vitro, the hydrostatic properties of the nucleus pulposus of normal lumbar intervertebral disc were proven. The hydrodynamic properties seem to exist also in the somewhat degenerated disc, but not in the more severely deranged ones. Intravitally-performed measurements of disc pressure over the last 20 years in more than 100 individuals have demonstrated how the load on the lumbar disc varies with the position of the subject's body and during the performance of various tasks, both in standing and in sitting. Compared with the pressure of load in the upright standing position, reclining reduces the pressure by 50-80%, while unsupported sitting increases the load by 40%, forward leaning and weight lifting by more than 100%, and the position of forward flexion and rotation by 400%. Large augmentations in pressure were also observed in subject performing various commonly prescribed strengthening exercises.

The crankshaft phenomenon after posterior Harrington fusion in skeletally immature patients with thoracic or thoracolumbar idiopathic scoliosis followed to maturity.

STUDY DESIGN: This retrospective study evaluated the progression of deformity after posterior fusion by reviewing 63 consecutive patients with idiopathic scoliosis who were all in Risser sign 0 at the time of surgery. All patients were observed beyond the time of skeletal maturity. Average follow-up time was 9 years and 8 months (range, 5-16 years). OBJECTIVES: To investigate the risk factors for the crankshaft phenomenon after posterior fusion and to build a model for predicting the probability of curve progression until maturation of growth. SUMMARY OF BACKGROUND DATA: There remains considerable controversy concerning the incidence, risk factors, and necessity of combined anterior fusion to prevent the crankshaft phenomenon in patients who are skeletally immature. METHODS: Serial radiographs were measured for Cobb angle, apical rotation according to Perdriolle, and apical rib-vertebra angle of Mehta. Multivariate and univariate logistic regression analysis was performed using seven potential predictors as independent variables and Cobb angle progression and rotational progression as dependent variables. RESULTS: Average progression of deformity was 3 degrees Cobb angle (range, -8-16 degrees) and 3 degrees Perdriolle rotation (range, -9-17 degrees). Progression of deformity more than 5 degrees of either Cobb angle or rotation was observed in 22 (35%) of 63 curves with 7 (11%) of 63 curves greater than 10 degrees. Chronologic age and skeletal age were found to be significantly associated with progression of deformity in univariate analysis. In multivariate analysis, only skeletal age seemed to be independently prognostic. The authors tried to build the logistic model using the three factors of chronologic age, skeletal age, and apical rib-vertebra angle. This model correctly classified 81% of all patients as progressive or nonprogressive. The positive predictive value was 90%. CONCLUSIONS: The results showed that patients with chronologic age of 11 years of younger, especially those with a skeletal age of 10 years or younger, had a high estimated probability of progression of deformity. The progression was fairly moderate, however, with an average Cobb angle of 9 degrees and average rotation of 7 degrees, which neither the patients nor the surgeon believed was of such magnitude as to warrant routine combined anterior fusion.

Childbearing, curve progression, and sexual function in women 22 years after treatment for adolescent idiopathic scoliosis: a case-control study.

STUDY DESIGN: A consecutive series of female patients with adolescent idiopathic scoliosis treated between 1968 and 1977, either with distraction and fusion using Harrington rods (n = 145) or with a brace (n = 122), were followed for at least 20 years after completion of the treatment. OBJECTIVES: To determine the long-term outcomes of childbearing and sexual life in women treated for adolescent idiopathic scoliosis, as compared with matched control subjects who did not have scoliosis. SUMMARY OF BACKGROUND DATA: The effect of pregnancy on curve progression is not established, and results are contradictory. Few reports exist on the social life (marriage, childbearing, and sexual function) of formerly treated individuals with scoliosis. METHODS: In this study, 136 surgically treated women (94%) and 111 brace-treated women (91%) completed the Scoliosis Research Society (SRS)/MODEM's questionnaire concerning childbearing and sexual life as a part of an unbiased personal follow-up examination. Of these, 129 surgically treated and 105 brace-treated women also underwent a radiographic examination. The Cobb method was used to measure curve size in present and earlier examinations. An age-matched control group of 90 women was randomly selected and subjected to the same examinations. RESULTS: The mean age for all the groups was 40 years. Of the surgically treated and brace-treated women, 85% were or had been married, as compared with 82% of the control women. In the total cohort, 628 pregnancies had occurred. No significant mean difference existed between the groups in the number of children born (1.8 for the surgically treated, 1.9 for the brace-treated, and 2 for the control women) (P = 0.25). The patients in the brace-treated group had a significantly higher mean age at first pregnancy (28 years) than the control subjects (25.9 years) (P = 0.011), whereas the age for the surgically treated women (26.6 years) did not differ significantly from that for the brace-treated women. There were no significant differences between the groups in rates for low back pain (35% for the surgically treated, 43% for the brace-treated, and 28% for the control group) or for cesarean section (19% for the surgically treated, 14% for the brace-treated, and 18% for the control group) during the first pregnancy. The rate of vacuum extractions was higher in the surgically treated group (16%) than in the control group (5%) (P = 0.036) or the brace-treated group(8%). Limitation of sexual function from the back was admitted by 33% of the surgically treated, 28% of the brace-treated, and 15% of the control women: surgically treated vs control subjects (P = 0.0042), brace-treated vs control subjects (P = 0.026), and brace-treated vs surgically treated subjects (P = 0.57, a nonsignificant difference). These limitations were largely because of difficulties participating physically in activities or self-consciousness about appearance. Pain was a minor reason for limitation. There was no correlation between progression of the major or lumbar curve and number of pregnancies, or between curve progression and age at first pregnancy. CONCLUSIONS: Patients treated for adolescent idiopathic scoliosis appeared to function well with regard to marital status and number of children. The scoliotic curve did not seem to increase as a result of childbearing. Minor problems occurred during pregnancy and delivery. Some patients, however, experienced a slight negative effect in their sexual life.

Valsalva maneuver biomechanics. Effects on lumbar trunk loads of elevated intraabdominal pressures.

The ability of a partial or full Valsalva maneuver (voluntary pressurization of the intraabdominal cavity) to unload the spine was investigated in four subjects. During the performance of five isometric tasks, intraabdominal and intradiscal pressures and surface myoelectric activities in three lumbar trunk muscle groups were measured. The tasks were carried out without voluntary pressurization of the intraabdominal cavity and then when the subjects performed partial and full Valsalva maneuvers. A biomechanical model analysis of each task was made to help interpret the experimental measurements. Intraabdominal pressure was found not to be an indicator of spine load in these experiments. The Valsalva maneuvers did raise intraabdominal pressure, but in four of the five tasks increased rather than decreased lumbar spine compressions occurred.

Mechanical properties of human lumbar spine motion segments. Influence of age, sex, disc level, and degeneration.

The influences of age, sex, disc level, and degree of degenration on the mechanical behavior of 42 fresh cadaver lumbar motion segments are reported. The motions and intradiscal pressure changes that result from the application of flexion, extension, lateral bending, and torsional moments; compression; and anterior, posterior, and lateral shears are described. The authors find that the mean behaviors of the different segment classes sometimes differ, but these differences are seldom pronounced. Scatter in the behavior of individual motion segments is pronounced, and very often overshadows any class differences.

The influence of backrest inclination and lumbar support on lumbar lordosis.

The influence of backrest inclination and lumbar support on the shape of the lumbar spine in sitting positions has been studied radiographically on 38 healthy subjects. Four angles of backrest inclination and four different sizes of lumbar support were studied. In addition, the lumbar support was placed at three different lumbar levels. When sitting down from a standing position, the pelvis rotates and the lumbar lordosis decreases. Increases in the backrest-seat angle had only minor effect on the lumbar lordosis. A lumbar support, on the other hand, had a significant influence: the lordosis increased with increasing support. The location of the lumbar support with respect to the level of the spine did not significantly influence the measured angles.

Effectiveness of braces in mild idiopathic scoliosis.

Despite the wide use of bracing for the treatment of idiopathic scoliosis, controlled studies apparently have not been performed to examine whether bracing, in fact, alters the natural history of spine lateral curves. We studied 255 female patients, ages 8-17 years, with idiopathic scoliosis who had curves with initial Cobb measures from 15-30 degrees. They were divided into two groups: one group consisted of 144 patients who had received a Milwaukee or Boston brace; and the other, a control group, consisted of 111 patients who remained untreated through a mean period of 1.9 years. The groups had similar mean ages, ages of menarche and curve severities. The results showed a slight but nonsignificant trend, suggesting that bracing reduced the overall probability of progression in the braced curves. However, noting that nearly 75% of the control group curves were nonprogressive, it is possible that a similar proportion of the braced curves need not have been braced. Moreover, bracing failed to prevent eight curves in seven patients (5%) from progressing. These curves progressed at a mean rate of 8 degrees per year. Our retrospective results suggest that bracing probably is not necessary in a large proportion of patients who meet current, clinical criteria for bracing. Given the limitations of retrospective studies like this one, a controlled prospective trial of bracing effectiveness in idiopathic scoliosis seems warranted.

Midterm follow-up of young patients fused in situ for spondylolisthesis.

To evaluate the results of posterolateral fusion alone (66 patients) and combined posterolateral and anterior fusion (39 patients) in situ, 105 consecutive patients younger than 25 years of age with spondylolisthesis, retrospectively were examined clinically and radiologically. The follow-up rate was 98% after a mean of 8.2 years (range, 2.0-15.3). Pre- and postoperative progression of slip was rare (6% and 1%, respectively), and no prognostic factors were found. The definite pseudarthrosis rate was 6%. In patients with low- and high-grade slip, 67% and 88% (respectively) were satisfied at follow-up, suggesting that the indication for operative treatment in patients with low-grade slip is relative.

Lumbar supports for prevention and treatment of low back pain: a systematic review within the framework of the Cochrane Back Review Group.

STUDY DESIGN: A systematic review of randomized and nonrandomized controlled trials. SUMMARY OF BACKGROUND DATA: Lumbar supports are used in the treatment of low back pain, but also to prevent the onset (primary prevention) or recurrences of a low back pain episode (secondary prevention). OBJECTIVES: To assess the effects of lumbar sup-ports for prevention and treatment of nonspecific low back pain. METHODS: The Medline, Cinahl, and Current Contents databases; the Cochrane Controlled Trials Register up to September 1999; and the Embase database up to September 1998 were all searched. References of identified trials and systematic reviews were reviewed and the Science Citation Index used to identify additional trials. Methodologic quality assessment and data extraction were performed by two reviewers independently. A quantitative analysis was performed in which the strength of evidence was classified as strong, moderate, limited or conflicting, and no evidence. RESULTS: Five randomized and two nonrandomized preventive trials and six randomized therapeutic trials were included in the review. Only 4 of the 13 studies were of high quality. There was moderate evidence that lumbar supports are not effective for primary prevention. No evidence was found on the effectiveness of lumbar supports for secondary prevention. The systematic review of therapeutic trials showed that there is limited evidence that lumbar supports are more effective than no treatment, whereas it is still unclear whether lumbar supports are more effective than other interventions for treatment of low back pain. CONCLUSIONS: There continues to be a need for high quality randomized trials on the effectiveness of lumbar supports. One of the most essential issues to tackle in these future trials seems to be the realization of adequate compliance.

A prospective study of work perceptions and psychosocial factors affecting the report of back injury.

A longitudinal, prospective study was conducted on 3,020 aircraft employees to identify risk factors for reporting acute back pain at work. The premorbid data included individual physical, psychosocial, and workplace factors. During slightly more than 4 years of follow-up, 279 subjects reported back problems. Other than a history of current or recent back problems, the factors found to be most predictive of subsequent reports in a multivariate model were work perceptions and certain psychosocial responses identified on the Minnesota Multiphasic Personality Inventory (MMPI). Subjects who stated that they "hardly ever" enjoyed their job tasks were 2.5 times more likely to report a back injury (P = 0.0001) than subjects who "almost always" enjoyed their job tasks. The quintile of subjects scoring highest on Scale-3 (Hy) of the MMPI were 2.0 times more likely to report a back injury (P = 0.0001) than subjects with the lowest scores. The multivariate model, including job task enjoyment, MMPI Scale-3, and history of back treatment, revealed that subjects in the highest risk group had 3.3 times the number of reports in the lowest risk group. These findings emphasize the importance of adopting a broader approach to the multifaceted problem of back complaints in industry and help explain why past prevention efforts focusing on purely physical factors have been unsuccessful.

A prospective study of the role of cardiovascular risk factors and fitness in industrial back pain complaints.

The authors conducted a prospective study of risk factors for industrial back pain complaints among 3,020 aircraft manufacturing employees. The study subjects completed a cardiovascular risk questionnaire, and were asked about their smoking status and past medical history, including previous back problems. Premorbid submaximal treadmill testing to predict maximum oxygen uptake (Vo2max) was completed in 2,434 subjects who were not excluded from testing due to cardiovascular risk screening. During several years of subsequent follow-up, 279 subjects reported back problems. Those who reported smoking at the time of the premorbid examination were significantly more likely to report a subsequent back problem than nonsmokers (P = 0.002). When controlling for sex and age, cardiovascular fitness, as measured through VO2max, was not predictive of future back injury reports (P = 0.26).

A prospective evaluation of preemployment screening methods for acute industrial back pain.

Preemployment screening methods have been ineffective in predicting those at risk, and in curbing the impact of back problems in industry. Such methods have centered on individual physical factors (capacities and clinical examination). This study evaluates commonly used physical examination measures and simple historical data for its ability to predict individuals at risk for future back injury reporting in the aircraft industry. In this study, once simple historical information about previous pain treatment was known, information gained from physical factors added no significant predictive value.

Pain sensitivity as a correlate of clinical status in individuals with chronic low back pain.

STUDY DESIGN: A cross-sectional study of baseline correlates of clinical pain and functional status in consecutive patients being treated for chronic low back pain. OBJECTIVES: To determine if an individual's global pain sensitivity, measured by experimental pain threshold to pressure at various regions of the body, is associated with baseline measures of clinical pain and physical functioning. SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated that in individuals with chronic low back pain, clinical pain and functional status are significantly associated with demographic, structural, and psychosocial factors. However, a large portion of variance remains unexplained. Because pain sensitivity (tenderness) has been shown to occur as a continuum in the population, the authors sought to determine if such sensitivity might be associated with clinical status in chronic low back pain, beyond what is known regarding demographic, structural, and psychosocial factors. METHODS: Forty-five patients with chronic low back pain were assessed for a variety of demographic, structural, and psychosocial factors, which previously have been shown to contribute to clinical status. In addition, all patients underwent testing for pain tolerance and threshold at various areas of the body. RESULTS: Age, degree of structural abnormality observed on magnetic resonance imaging, and depressive symptoms were all significantly correlated with either clinical pain or functional status. Pain sensitivity, the target of this investigation, accounted for significant proportions of variance in functional status and pain, even after controlling for demographic, structural, and psychosocial variables. CONCLUSIONS: These pilot data suggest that an individual's experimental pain threshold (a measure of tenderness) is associated with baseline functional status and pain in cases of chronic low back pain and may represent an important domain warranting further investigation.

The role of spinal flexibility in back pain complaints within industry. A prospective study.

Commonly used clinical measurements of spinal flexibility in the sagittal and frontal planes were examined as predictors of future back pain reports within industry. The study sample consisted of 3,020 aircraft manufacturing employees who were examined and tracked for more than 4 years for reports of back pain. Modified Schober, sit-and-reach, and lateral bending measurements were not significantly associated with risk of future back pain reporting, nor were any trends present. There was a statistically significant relationship between decreased flexibility and reports of current or previous back problems. However, the differences in flexibility between subjects with and without a history of back problems were too small to be of practical significance.