Clinic-based training in comparison to home-based training after first-time lumbar disc surgery: a randomised controlled trial

The effectiveness of physiotherapy after first-time lumbar disc surgery is still largely unknown. Studies in this field are heterogeneous and behavioural treatment principles have only been evaluated in one earlier study. The aim of this randomised study was to compare clinic-based physiotherapy with a behavioural approach to a home-based training programme regarding back disability, activity level, behavioural aspects, pain and global health measures. A total of 59 lumbar disc patients without any previous spine surgery or comorbidity participated in the study. Clinic-based physiotherapy with a behavioural approach was compared to home-based training 3 and 12 months after surgery. Additionally, the home training group was followed up 3 months after surgery by a structured telephone interview evaluating adherence to the exercise programme. Outcome measures were: Oswestry Disability Index (ODI), physical activity level, kinesiophobia, coping, pain, quality of life and patient satisfaction. Treatment compliance was high in both groups. There were no differences between the two groups regarding back pain disability measured by ODI 3 and 12 months after surgery. However, back pain reduction and increase in quality of life were significantly higher in the home-based training group. The patients in the clinic-based training group had significantly higher activity levels 12 months after surgery and were significantly more satisfied with physiotherapy care 3 months after surgery compared to the home-based training group. Rehabilitation after first-time lumbar disc surgery can be based on home training as long as the patients receive both careful instructions from a physiotherapist and strategies for active pain coping, and have access to the physiotherapist if questions regarding training arise. This might be a convenient treatment arrangement for most patients.     

Modic type I changes and recovery of back pain after lumbar microdiscectomy

Purpose

To investigate whether the presence of Modic changes type I (MC I) found on preoperative MRI scans represent a risk factor for persistent back pain 12 months after surgery amongst patients operated for lumbar disc herniation.

Methods

Cohort study of 178 consecutive patients operated with lumbar microdiscectomy. Preoperative MRI scans were evaluated by two independent neuroradiologists. Primary outcome measure was the visual analogue scale (VAS) for back pain. Secondary outcome measures were; VAS for leg pain, physical function (Oswestry Disability Index), and health-related quality of life (EQ-5D), self-reported benefit of the operation and employment status. The presence of MC I was used as exposition variable and adjusted for other risk factors in multivariate analyses.

Results

The Modic classification showed a high inter-observer reproducibility. Patients with MC I had less improvement of back pain 12 months after surgery, compared to those who had no or other types of MC, but this negative association no longer showed statistical significance when adjusted for smoking, which remained the only independent risk factor for persistent back pain.

Conclusions

Patients with preoperative MC I can expect less but still significant improvement of back pain 1 year after microdiscectomy, but not if they smoke cigarettes.     

手术治疗腰椎间盘突出症的长期疗效及其影响因素

目的:评估腰椎间盘突出症手术治疗的长期疗效,探讨影响手术长期疗效的相关因素。方法:回顾性分析1996年2月～2002年12月在我院采用单纯开窗减压髓核摘除术治疗的125例单节段腰椎间盘突出症患者,记录患者性别、年龄、体重指数(body mass index,BMI)、病程、临床表现、体征、手术减压时椎间盘的突出类型和末次随访时复发性椎间盘突出症的例数。分别记录术前和末次随访时Oswestry伤残指数(Oswestry Disability Index,ODI)及腰痛/下肢根性痛的视觉模拟评分(visual analog scale,VAS)。根据Stauffer-Coventry′s(SC)疗效评定标准评价患者总体疗效。单因素分析患者术前与末次随访时的VAS以及ODI。患者总体疗效作为结果变量,单因素分析年龄、性别、BMI、吸烟、腰扭伤史、病程、术前腰痛VAS评分、术前下肢痛VAS评分、术前ODI、直腿抬高试验(straight-leg raise test,SLR)、肌力、感觉、椎间盘突出节段和类型等14项指标与疗效的关系。用非条件Logistic全回归分析和逐步回归分析来研究结果变量与术前各种指标的关系。结果:随访84～123个月,平均109个月,患者总体疗效优占32%,良占35.2%,可占23.2%,差占9.6%,复发率为8%。术前ODI为(72.23±25.72)%,末次随访时为(15.64±17.52)%,与术前比较有显著性差异(P<0.05)。腰痛VAS评分术前为5.44±3.43分,末次随访时为2.12±2.32分;下肢痛VAS评分术前为7.34±3.72分,末次随访时为1.42±2.74分;末次随访时与术前比较均有显著性差异(P<0.05)。全回归分析发现腰扭伤史、感觉减退是总体疗效不佳的相关因素,而非包含型突出类型是总体疗效佳的相关因素。逐步回归分析发现有4个有统计学意义的相关因素,其比值比(OR)及95%可信区间分别为:腰扭伤史(OR=6.50;95%CI 2.21-19.10)、吸烟(OR=4.48;95%CI 1.51-13.34)、感觉(OR=9.01;95%CI 1.75-46.46)、突出类型(OR=0.027;95%CI 0.005-0.145)。结论:手术治疗可以明显改善腰椎间盘突出症患者的腰痛、下肢痛和ODI。腰扭伤史、吸烟史、术前感觉和突出类型是影响腰椎间盘突出症手术长期疗效的相关因素。     

腰椎间盘退变性疾病危险因素分析及治疗

目的探索腰椎间盘退变性疾病的危险因素,为该类疾病的预防和治疗提供依据。方法采用病例对照研究方法,在2008-06-2010-03我院脊柱专科门诊确诊为腰椎间盘退变性疾病的960例患者中随机抽取118例设为病例组,体检中心随机抽取167例无下腰痛病史人员为对照组,问卷调查性别、年龄、身高、体重、职业工种、腰背部外伤史、腰椎疾病家族史等,建立单因素四格表资料的F检验和多因素非条件Logistic回归分析。结果单因素四格表资料的F检验和非条件Logistic回归分析结果显示超重、固定工作体位、腰背部外伤史、腰椎疾患家族史是该地区居民腰椎间盘退变的危险因素。结论腰椎间盘退变性疾病患者的发病与肥胖、职业工种、腰椎疾患家族史、腰背部外伤史等因素有密切的关系,治疗应个体化多样化,并加强健康卫生宣教。     

The significance of high lumbar mobility and low lumbar strength for current and future low back pain in adolescents.

STUDY DESIGN: This study comprised a cross-sectional part and a prospective part. OBJECTIVE: To study whether low lumbar extension strength, high lumbar mobility, and high mobility-extension strength ratios are related to current and future low back pain in adolescents. SUMMARY OF BACKGROUND DATA: Knowledge is sparse about the significance of lumbar mobility and strength for low back pain in adolescents. METHODS: The study population included all the adolescents in the eighth and ninth grades of a rural municipality (n = 44) and in an urban area (n = 61) during the 1996-1997 school year. At baseline, 88 adolescents (mean age, 14.7 years) participated in the study, giving a response rate of 84%. Low back pain was assessed by questionnaire as pain or discomfort in the low back during the preceding year. Sagittal lumbar mobility was tested by Schober's modified technique, and lumbar strength as static endurance extension strength. The follow-up part was conducted 3 years later, which included 98% of the adolescents. RESULTS: By bivariate and multivariate analyses in the cross-sectional part of the study, low back pain was found to be highly associated with low lumbar extension strength (P = 0.004-0.02), and high lumbar mobility-extension strength ratios (P = 0.005-0.04). Baseline low lumbar extension strength and high lumbar sagittal mobility-extension strength ratios (P = 0.03 and P = 0.02, respectively) predicted low back pain at follow-up assessment in multivariate analyses when control was used for gender, previous low back pain, physical activity, and well-being. No associations were found between plain sagittal mobility and low back pain. CONCLUSION: The study findings support theories suggesting insufficient strength and stability in the low back as important factors for both concurrent and future low back pain in adolescents.     

Patient characteristics and patterns of use for lumbar spine radiographs: results from the Veterans Health Study

STUDY DESIGN: Longitudinal data from the Veterans Health Study, an observational study of male patients receiving Veterans Administration ambulatory care, were analyzed. OBJECTIVE: To identify patient characteristics that predict different patterns in the use of lumbar spine radiographs. SUMMARY AND BACKGROUND DATA: In this study, 401 patients with low back pain receiving ambulatory care services in four Veterans Administration outpatient clinics in the greater Boston area were followed for 12 months. METHODS: Participants were mailed the Medical Outcome Study Short Form Health Survey and participated in scheduled interviews that included the completion of a low back questionnaire, a comorbidity index, and a straight leg raising test. Four groups of patients were defined according to the patterns of use for lumbar spine radiographs: prior use, repeat use, no use, and new use of lumbar spine radiographs. These groups were compared in terms of sociodemographics, comorbid conditions, low back pain intensity, radiating leg pain, straight leg raising, Medical Outcome Study Short Form Health Survey scores, and low back disability days. RESULTS: The patients with new lumbar spine radiographs showed worse physical and psychological distress than the participants in the other three groups. In contrast, the patients with no lumbar spine radiographs reported minor physical impairment. Compared with patients who had no repeat radiographs, patients with repeat lumbar spine radiographs had similar scores on physical health, but they showed worse scores of mental health. CONCLUSIONS: Both physical and psychological factors contribute to having new radiographic examinations, whereas psychological factors have increased importance in the repeat use of roentgenographic examinations. Repeat radiographs appear to be overused, judging by the severity of physical impairment as measured by low back pain intensity, the Medical OutcomeStudy Short Form Health Survey, and disability days.     

Serial lumbar dynamometry in low back pain.

To determine the significance of changes in motor performance as measured by lumbar dynamometry, serial lumbar dynamometry was performed on a group of 45 male Workers' Compensation patients with chronic "mechanical" low back pain and in a group of 20 healthy male volunteers. The patients were men aged 20-60 years, whose current episode of low back pain had lasted for at least 3 months (mean 19.5 weeks, range 12-47 weeks). Testing was performed at entry into a "back school" program of therapy and again 2 weeks and 4 weeks later. The control group showed a slight improvement in almost all variables of strength and range of motion between the first and second tests but no significant change between the second and third tests. This was consistent with a learning effect. The patient group was analyzed as a whole and also in two groups based on their response to the Waddell maneuvers at entry: Waddell score 0-2 (no excessive illness behavior) and 3-5 (excessive illness behavior). As a whole, the patients showed significant progressive improvement in most variables on successive tests. The group with the low Waddell score had significantly greater strength and range of motion than the group with the high Waddell score but the trend of improvement with time was similar in the two groups. The authors conclude that in this sample of patients with low back pain, serial lumbar dynamometry reveals a progressive improvement in performance, which is greater than the improvement expected from the natural history of physical recovery and greater than the improvement expected from an increase in strength and range of motion attributable to the therapeutic exercises performed and is much larger than any learning effect related to the test procedure.     

人工髓核置换术治疗腰椎间盘病变的中远期随访结果

目的 探讨人工髓核置换术治疗腰椎间盘病变的中远期疗效和影响因素.方法 回顾性分析2002年3月至2003年10月采用人工髓核置换术治疗的34例腰椎间盘病变患者的临床资料.其中椎间盘源性腰痛20例,腰椎间盘突出症14例;随访时间48～66个月,平均52.6个月.采用Oswestry功能障碍指数(ODI)评分和疼痛视觉模拟评分法(VAS)评估患者术后改善情况和中远期功能.术前ODI评分平均58.4%,VAS评分平均7.4分.对放射学资料进行手术节段活动度、手术节段椎间隙高度变化对比研究.结果 术后早期腰痛及下肢痛症状明显缓解,术后12个月ODI评分平均18.2%,VAS评分平均1.8分,椎间隙高度较术前平均增加17.6%,手术节段活动度平均为9.2°.末次随访时,患者下肢放射性疼痛缓解满意,18例患者下腰痛逐渐加重,ODI评分平均为31.2%,VAS评分平均为3.1分.椎间隙高度较术前平均下降13.5%,手术节段活动度平均为6.8°,植入物移位发生率73.5%(25/34),软骨终板退变损伤发生率64.7%(22/34).结论 人工髓核置换术尚不能达到长期维持手术节段椎间隙高度的目的 ,术后手术节段活动度逐渐减少,下腰痛逐渐加重影响其中远期疗效,明确术前诊断和严格手术指征非常重要.     

Recurrent low back pain and early disc degeneration in the young.

STUDY DESIGN: A prospective 9-year follow-up study involving randomized matched subgroups of 15-year-old schoolchildren with or without low back pain at baseline. OBJECTIVES: To evaluate the long-term persistence of initially reported recurrent low back pain, and to examine the significance of abnormalities found in magnetic resonance imaging of lumbar discs in individuals 15 and 18 years of age as possible contributors to persistently recurrent low back pain. SUMMARY OF BACKGROUND DATA: In surveys among children and teenagers during the past few years, as many as half of all children in a community report a history of low back pain. The current results, in accordance with previous findings, indicate that there is a subgroup of adolescents with more chronic symptoms which, in the authors' opinion, deserves more attention. Disc disease accompanying low back pain is a key issue both in research and clinical practice. The significance of early degenerative findings in the lumbar discs is not known. METHODS: In the survey of 14-year-olds (n = 1503), a subgroup (7.8%) with recurrent low back pain was found. A random sample of individuals with recurrent low back pain (n = 40) and an equal number of completely asymptomatic control subjects were selected for a comparative study. The selected groups were examined by magnetic resonance imaging at 15 and 18 years of age. The participation rate of youth at 14, 18, and 23 years of age for all three questionnaires was 82% (29 boys and 33 girls). Imaging data were interpreted by two blinded radiologists experienced in low-field-strength magnetic resonance imaging. In calculations of relative risks, the participants reporting recurrent low back pain in all phases of the study were compared with participants who had no persistently recurrent pain. RESULTS: Eleven participants (35%) in the original group with low back pain persistently reported recurrent pain. In 15-year-old participants with disc degeneration, the relative risk of reporting recurrent low back pain up to the age of 23 years was 16 (95% confidence interval 2.2-118) compared with those having no disc degeneration. In addition, disc protrusion and Scheuermann-type changes at 15 years contributed to the risk of persistently recurrent low back pain. CONCLUSIONS: The authors' earlier findings already favored the hypothesis of a causal relation between the early evolution of a degenerative process of lower lumbar discs and recurrent low back pain in the near future. The current results further strengthen this hypothesis, indicating that individuals with disc degeneration soon after the phase of rapid physical growth not only have an increased risk of recurrent low back pain at this age, but also a long-term risk of recurrent pain up to early adulthood.     

One-year predictive factors for various aspects of neck disorders.

STUDY DESIGN: A longitudinal epidemiologic study conducted over 12 months among active workers in different occupations. The study was primarily designed to evaluate intervention for prevention of low back and other spinal disorders. OBJECTIVE: To determine factors that predict incidence, recurrence, and persistence of neck disorders (ND), taking into account various dimensions of ND. SUMMARY OF BACKGROUND DATA: Neck pain is often supposed to have essentially the same risk factors as back pain; however, there is comparatively little data relevant to this issue. Moreover, there is a lack of prospective studies that take into account a diversity of predictive factors. METHODS: The Nordic questionnaire for the analysis of musculoskeletal symptoms was completed twice at a 12-month interval by 568 workers. Predictive factors were studied with logistic models for four dimensions of ND from the second questionnaire: 1) any ND in the past 6 months; 2) ND for more than 30 days; 3) treatment for ND; and 4) visit to a health care professional for ND. The predictive factors were obtained from the first questionnaire and included gender, age, occupational group, level of psychological distress and psychosomatic problems, and ND at baseline. RESULTS: Female gender and older age were predictors of ND. Headaches or pain in the head, psychological distress, and psychosomatic problems were predictors for all dimensions of ND. These effects were observed for both incidence and persistence of ND. CONCLUSIONS: The results emphasize the role of psychosomatic and psychological factors in the occurrence and course of ND for various dimensions of the disorder.     

Impaired postural control of the lumbar spine is associated with delayed muscle response times in patients with chronic idiopathic low back pain

STUDY DESIGN: Balance performance in unstable sitting and trunk muscle response to quick force release were measured in 16 patients with chronic low back pain and 14 matched healthy control subjects. OBJECTIVES: To determine whether patients with low back pain will exhibit poorer postural control, which will be associated with longer average muscle response times. SUMMARY OF BACKGROUND DATA: Larger postural sway during standing and delayed trunk muscle response times for patients with low back pain have been reported in several independent studies. METHODS: Unstable sitting test was accomplished by attaching different sized hemispheres to the bottom of a seat. Subjects performed trials with eyes open and closed while the displacements of the center of pressure were measured with a force plate underneath the seat. Response to a quick force release was recorded from 12 major trunk muscles with surface electromyography. Subjects performed isometric trunk exertions in a semi-seated position when the resisted force was suddenly released with an electromagnet. Average muscle response times and balance performance were correlated using a linear regression analysis. RESULTS: Patients with low back pain demonstrated poorer balance performance than healthy control volunteers, especially at the most difficult levels. Patients also had delayed muscle response times to quick force release. Average muscle onset times together with age and weight correlated significantly with balance performance with closed eyes (R(2) = 0.46), but not with eyes opened (R(2) = 0.18). CONCLUSIONS: Patients with chronic low back pain demonstrated poorer postural control of the lumbar spine and longer trunk muscle response times than healthy control volunteers. Correlation between these two phenomena suggests a common underlying pathology in the lumbar spine.     

To what extent do current and past physical and psychosocial occupational factors explain care-seeking for low back pain in a working population? Results from the Musculoskeletal Intervention Center-Norrtälje Study

STUDY DESIGN: A population-based case referent study. OBJECTIVES: To determine whether current and past physical and psychosocial occupational factors are associated with care-seeking for low back pain in working men and women. SUMMARY OF BACKGROUND DATA: The importance of physical and psychosocial workloads as causal factors of low back pain has mostly been investigated in special occupational groups and with a cross-sectional design, which makes generalizability and interpretations more difficult. METHODS: The study comprised 2118 working men and women 20 to 59 years old (695 cases, and 1423 referents). Cases were defined as persons seeking care by any caregiver for low back pain. The exposure assessments were made through questionnaires and interviews about current and past physical and psychosocial loads during work and leisure time. RESULTS: In a logistic regression analysis, physical load from forward bending in men (RR = 1.8) and high physical load, in general, in women (RR = 2.0) showed increased relative risks. Psychosocial factors alone seemed to be of less importance in women, but "poor job satisfaction" and "mostly routine work without possibilities of learning" increased the risk in men. Combined current and past exposures further increased the risks. A combination of high physical and psychosocial loads increased the risk substantially, but few were exposed to such loads. Adjustment for lifestyle and other loads outside work did not change the results. CONCLUSION: Current and past physical and psychosocial occupational factors, both separately and combined, seem to be gender-specific, and to have a moderate impact on care-seeking for low back pain in a general working population.     

腰椎Active-L人工椎间盘置换术与腰椎融合术的临床比较研究

背景：腰椎融合术一直被广大学者认为是治疗腰椎间盘退行性病变的“金标准”,但文献报道腰椎融合术加速相邻节段退变的发生,为保留脊柱功能单位的生理和运动特性,提出人工椎间盘置换术。目的：比较前路Active．L型人工椎间盘假体置换术和后路腰椎融合术治疗单节段腰椎间盘退行性病变患者的疗效和安全性。方法：2009年1月至2010年4月62例因腰椎间盘退行性病变的手术患者,根据手术方式分为试验组和对照组。试验组行腰椎人工椎间盘置换术患者20例,男10例,女10例;年龄36-58岁,平均47．7岁;术前诊断：腰椎间盘突出症16例,腰椎间盘源性下腰痛4例,腰椎间盘后路开窗术后复发1例;手术节段：13-42例,L4-513例,L5-S15例。对照组行腰椎融合术患者42例,男22例,女20例;年龄40-60岁,平均48．5岁;术前诊断：腰椎间盘突出症32例,腰椎间盘源性下腰痛7例,腰椎间盘后路开窗术后复发3例;手术节段：13-44例,L4-526例,15-S112例。随访观察指标包括：（1）临床疗效评定：术后疼痛及功能改善率的评定;手术成功率的评定。（2）影像学评定：腰椎前凸角和手术节段的椎问活动度独立因素t检验进行对比评价。结果：全部获得随访,试验组随访时间为12-27个月,平均19．3个月;对照组随访时间为12-27个月,平均19．8个月。两组患者在治疗下腰痛方面均取得明显疗效。在改善ODI功能评分、VAS疼痛评分、SF-36、椎间隙活动度上,试验组优于对照组,两组间比较有显著性差异（P〈0．05）;在恢复腰椎前凸序列上,两组间无显著性差异（P〉0．05）;两组均未出现严重并发症。结论：人工椎间盘置换术和融合术均取得良好的临床效果,但人工椎间盘置换术在掌握严格的手术适应证和禁忌证的条件下,相比腰椎融合术具有更好的临床疗效并保留病变节段的活动度。因此,在合适的手术适应证下,人工间盘置换术是一种更优且可以替代腰椎融合术的有效治疗方法。     

Predictors of new vertebral endplate signal (Modic) changes in the general population

Vertebral endplate signal changes (VESC), also known as Modic changes, have been reported to be associated with low back pain (LBP). However, little is known about predisposing factors for the development of new VESC. The aim of this study was to investigate the predictive value of lifestyle factors and disc-related magnetic resonance imaging (MRI) findings in relation to the development of new VESC. This prospective observational study included 344 people from the Danish general population who had an MRI and completed LBP questionnaires at the age of 40 and again at 44 years. Potential predictors of new VESC were female gender, disc-related MRI findings (disc degeneration, disc bulges, disc herniation, and other endplate changes) and lifestyle factors [high physical work or leisure activity, high body mass index (BMI), and heavy smoking]. Bivariate and multivariate logistic regressions were used to identify predictors of new VESC. New VESC at the age of 44 appeared in 67 of the 344. The majority (84%) of these new signal changes were type 1 VESC and almost half (45%) were only in the endplate and did not extend into the vertebral body. In the multivariate analysis, lumbar disc levels with disc degeneration, bulges or herniations at 40 were the only predictors of new VESC at age 44. Therefore, the development of new VESC at the age of 44 appears to be based on the status and dynamics of the disc, rather than being the result of gender or lifestyle factors such as smoking and physical load.     

腰椎退行性疾患接受腰椎融合术后发生下腰痛和腰椎矢状位序列的相关性研究

目的探讨分析腰椎退行性疾患接受腰椎融合术后发生下腰痛和腰椎矢状位序列的相关性。方法回顾性分析我院于2010年2月~2011年6月收治的38例接受腰椎融合术的腰椎退行性疾病且术后发生下腰痛患者的临床资料,于所有患者出院后进行为期24个月的随访。在手术前及随访期间收集所有患者站立位X线片腰椎前凸的Cobb角,并分析其与患者下腰痛程度之间的相关性。结果术后12个月及24个月与手术前的腰椎矢状位Cobb角比较,均无统计学意义(分别为t=0.042,P=0.967及t=0.268,P=0.789);术后12个月及24个月的腰椎矢状位Cobb角与正常角度的差值与手术前比较均无统计学意义(分别为t=0.450,P=0.900及t=0.174,P=0.862)。术后12个月及24个月的VAS评分与手术前相比,有明显改善(分别为t=2.838,P=0.006及t=3.251,P=0.002),而术后12个月及24个月的ODI评分与手术前相比也有明显改善(分别为t=2.300,P=0.024及t=3.320,P=0.001)。术后12个月及24个月所有患者的腰椎前凸丢失与VAS评分及ODI评分均呈正相关(P0.05)。结论腰椎前凸角度的丢失与腰椎退行性疾患腰椎融合术后的腰痛关系密切,手术过程中腰椎前凸的重建十分重要。     

Prognosis of chronic low back pain in patients presenting to a private community-based group exercise program

Purpose

To examine the prognosis and prognostic factors for patients with chronic low back pain presenting to a private, community-based, group exercise program.

Methods

A total of 118 consecutive patients with chronic LBP were recruited. Baseline assessments included socio-demographic characteristics, back pain history and clinical examination findings. Primary outcome measures were pain intensity and disability at 3, 6 and 12 months. Potential prognostic factors to predict pain intensity and disability at 12 months were assessed using a multivariate regression model.

Results

112 (95 %) participants were followed up at 12 months. The majority of participants were female (73 %), had high educational levels (82 %) and resided in suburbs with a high socio-economic status (99 %). Pain intensity improved markedly during the first 6 months (35 %) with further minimal reductions up to 12 months (39 %). Interestingly, disability improved to a greater degree than pain (48 % improvement at 6 months) and continued to improve throughout the 12 months (60 %). Baseline pain intensity accounted for 10 % of the variance in the 1 year pain outcomes. Duration of current episode, baseline disability and educational level accounted for 15 % of the variation in disability at 12 months.

Conclusions

During a period of 12 months, patients with chronic LBP presenting to a private, community-based, group exercise program improved markedly, with greater improvements in disability than pain. The predictors investigated accounted for only 10 and 15 % of pain and disability outcomes, respectively.     

The association between physical workload and low back pain clouded by the "healthy worker" effect: population-based cross-sectional and 5-year prospective questionnaire study

STUDY DESIGN: A population-based cross-sectional and 5-year prospective questionnaire study. OBJECTIVE: To investigate self-reported physical workload as a risk factor for low back pain. SUMMARY OF BACKGROUND DATA: Both physical and psychosocial workplace factors are considered risk factors for low back pain. However, today no consensus has been reached regarding the exact role of these factors in the genesis of low back pain. METHODS: Questionnaire data were collected at baseline for 1397 (and after 5 years for 1163) men and women aged 31--50 years at baseline. Low back pain ("any low back pain within the past year," "low back pain < or = 30 days in total during the past year," "low back pain > 30 days in total during the past year") was analyzed in relation to physical workload (sedentary, light physical, and heavy physical work) using logistic regression and controlling for age, gender, and social group. The proportions of workers changing between the workload groups over the 5-year period were analyzed in relation to low back pain status. RESULTS: At baseline no statistically significant differences in low back pain outcomes were found for workers exposed to sedentary, light physical, or heavy physical work. This was true for all age, gender, and social groups. At follow-up there was a statistically significant dose-response association between any low back pain and longstanding low back pain within the past year and increasing physical workload at baseline also after controlling for age, gender, and social group. Subjects with heavy physical workload at baseline changed statistically significantly more often to sedentary work if they experienced low back pain for more than 30 days out of the past year. CONCLUSIONS: Having a sedentary job might have a protective or neutral effect in relation to low back pain, whereas having a heavy physical job constitutes a significant risk factor. Because of migration between exposure groups (the "healthy-worker" effect), longitudinal studies are necessary for investigating the associations between physical workload and low back pain.     

Somatic and psychologic predictors of long-term unfavorable outcome after surgical intervention

OBJECTIVE: To identify somatic and psychologic predictors of pain, functional limitations, global perceived recovery, and quality of life 6 months after surgical intervention. SUMMARY BACKGROUND DATA: Recent studies have indicated that chronic pain after surgical intervention is more common than previously assumed. Several demographic and somatic predictors of long-term unfavorable outcome have been identified, but little is known about the contribution of psychologic risk factors. METHODS: A prospective cohort study, including 625 patients undergoing elective surgery at the University Hospital Maastricht, The Netherlands, was conducted between February and August 2003. Psychologic questionnaires were completed preoperatively and acute postoperative pain was recorded until 4 days after the operation. Six months later, all patients received follow-up questionnaires to assess pain, functional limitations, global perceived recovery, and quality of life. Multivariable logistic regression analyses were used to estimate relative risk of poor outcome in terms of pain, functional limitations, and global recovery. Multivariable linear regression analysis was used to assess associations with quality of life at 6 months. RESULTS: The most important somatic predictors of unfavorable outcome were duration of the operation and high levels of acute postoperative pain. Patients reporting high levels of pain 4 days after the operation and patients undergoing an operation of longer than 3 hours were at risk for increased pain, increased functional limitations, poor global recovery, and reported lower levels of quality of life 6 months after the operation. Psychologic variables that influenced long-term outcome were preoperative fear of surgery and optimism. Fear of the long-term consequences of the operation was associated with more pain, poor global recovery, and worse quality of life 6 months later, whereas optimism was associated with better recovery and higher quality of life. CONCLUSIONS: This study was the first to identify the joint contribution of somatic and psychologic factors to chronic pain, functional limitations, and quality of life 6 months after surgical interventions. It replicates previous findings that intense acute postoperative pain is a risk factor for long-term adverse outcome and also identified additional risk factors, namely, long duration of the operation, ASA status, and preoperative fear of surgery.