Responsiveness of the Zurich Claudication Questionnaire in Patients with Lumbar Spinal Stenosis Undergoing Nonsurgical Treatment: A Secondary Analysis of a Randomized Controlled Trial.

STUDY DESIGN: Secondary analysis of a randomized controlled trial. OBJECTIVE: We investigated the ability to distinguish patients with lumbar spinal stenosis (LSS) who improved from those who did not after receiving nonsurgical treatment. We used the disorder-specific Zurich Claudication Questionnaire (ZCQ) satisfaction subscale as an external anchor and estimated the minimal clinically important differences (MCIDs) for the ZCQ symptom severity and physical function subscales. SUMMARY OF BACKGROUND DATA: The ZCQ satisfaction subscale effectively distinguishes surgical patients who improved from those who did not for LSS. However, its responsiveness in nonsurgical treatment has not been evaluated yet. METHODS: Eighty-four patients with LSS who received supervised physical therapy or a home exercise program were included. Patients were classified as responders or nonresponders according to the cutoff of 2.5 for the ZCQ satisfaction subscales at 6 weeks and 1 year. The external responsiveness of the ZCQ satisfaction subscale was assessed using correlational and receiver-operating characteristic (ROC) curve analyses. MCIDs for the ZCQ symptom severity and physical function subscales were estimated using anchor and distribution approaches. RESULTS: Pearson's correlation coefficients between the changes in outcomes and the ZCQ satisfaction subscale at 6 weeks and 1 year were 0.37-0.58 (symptom severity) and 0.40-0.45 (physical function subscales) (>0.30 is considered a good anchor). The area under the ROC curve values were 0.66-0.72 and 0.63-0.71 for the symptom severity and physical function subscales, respectively (>0.7 is considered acceptable). The MCIDs at 6 weeks and 1 year estimated from anchor-based approaches were -0.64 to -0.13 (symptom severity) and -0.39 to 0.10 (physical function), and those from the distribution-based approaches were -0.31 to -0.30 and -0.29 to -0.27, respectively. CONCLUSION: The findings of this study suggest that the ZCQ satisfaction subscale has less ability to distinguish patients with LSS who improved in the ZCQ symptom severity and physical function subscales from those who did not after nonsurgical treatment, compared to those after surgical treatment.

Minimal clinically important differences in walking capacity and physical activity after nonsurgical treatment in patients with lumbar spinal stenosis: a secondary analysis of a randomized controlled trial.

BACKGROUND CONTEXT: Little information is available about the minimal clinically important differences (MCIDs) for objective physical measurements in people with lumbar spinal stenosis (LSS). PURPOSE: To use disorder-specific anchor and, multiple anchor-, and distribution-based approaches to determine the MCIDs for walking capacity and physical activity in patients with LSS receiving nonsurgical treatment. STUDY DESIGN/SETTING: Secondary analysis of a randomized controlled trial. PATIENT SAMPLE: Sixty-nine patients with neurogenic claudication caused by LSS receiving outpatient physical therapy. OUTCOME MEASURES: Zurich claudication questionnaire (ZCQ), self-paced walking test (SPWT), and number of daily steps measured by pedometry. METHODS: All patients completed the ZCQ, SPWT, and pedometry at the baseline and after 6 weeks. For the anchor-based approach, ZCQ symptom severity, physical function, and satisfaction subscales were used as the external anchors. Using the receiver-operating characteristic (ROC) curve, the MCIDs were determined based on the optimal cutoff points for changes in the SPWT or daily steps. For the distribution-based approach, the MCIDs were estimated from the standard deviations (SDs) of the baseline scores of the SPWT and daily steps. RESULTS: In the anchor-based approach, only the ZCQ satisfaction subscale for the SPWT (0.73), and ZCQ symptom severity subscale for daily steps (0.71) exceeded the area under the ROC curve value of 0.7, which is considered acceptable. When using these subscales as anchors, the ROC curves and optimal cutoff points indicated MCIDs of 151 m for the SPWT and 1,149 steps for daily steps. The distribution-based approach estimated the MCIDs as 280 m for the SPWT and 1,274 steps for daily steps, and had a moderate effect size (0.5 SD). CONCLUSIONS: The anchor-based approach had limited external responsiveness when the ZCQ was used as the anchor. However, this information may be helpful for interpreting walking capacity and physical activity in patients with LSS receiving nonsurgical treatment and for estimating power and sample size when planning new trials.

Lumbar paraspinal muscle morphology is associated with spinal degeneration in patients with lumbar spinal stenosis.

BACKGROUND CONTEXT: Lumbar spinal stenosis (LSS) has been reported to induce changes in paraspinal muscle morphology, but objective physical function and degenerative spine conditions are rarely assessed. PURPOSE: To identify factors associated with paraspinal muscle morphology using objective physical and degenerative spine assessments in patients with LSS. STUDY DESIGN/SETTING: Cross-sectional design. PATIENT SAMPLE: Seventy patients with neurogenic claudication caused by LSS, receiving outpatient physical therapy. OUTCOME MEASURES: Cross-sectional area (CSA) and functional CSA (FCSA) of the multifidus, erector spinae, and psoas muscles, the severity of stenosis, disc degeneration, and endplate abnormalities were evaluated by magnetic resonance imaging, as well as sagittal spinopelvic alignment by X-ray. Objective physical assessments included pedometry and claudication distance. Patient-reported outcomes included the numerical rating scale of low back pain, leg pain, and leg numbness, and the Zurich Claudication Questionnaire. METHODS: To assess the impact of LSS on paraspinal muscles, FCSA and FCSA/CSA were compared between the dominant and nondominant sides based on the patients' neurogenic symptoms, and multivariable regression analyses adjusted for age, sex, height, and weight were performed; p<.05 was considered significant. RESULTS: Seventy patients were analyzed. At one level below the maximum stenotic level, erector spinae FCSA on the dominant side was significantly lower than that on the nondominant side. In the multivariable regression analyses, at one level below the symptomatic level, disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment, such as decreased lumbar lordosis and increased pelvic tilt, were negatively associated with multifidus FCSA and FCSA/CSA ratio. A significant association was observed between dural sac CSA and erector spinae FCSA. Throughout L1/2 to L5/S, disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment were negatively associated with multifidus and erector spinae FCSA or FCSA/CSA. CONCLUSIONS: Lumbar paraspinal muscle asymmetry caused by LSS was observed only in erector spinae. Disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment, rather than spinal stenosis and LSS symptoms, were more associated with paraspinal muscle atrophy or fat infiltration.

Branched-chain amino acids plus vitamin D supplementation promote increased muscle strength following lumbar surgery for lumbar spinal stenosis: a randomized trial.

BACKGROUND CONTEXT: Adequate nutrition is essential to address the surgical stress response and mitigate loss of muscle mass, strength, and functionality in older adults with lumbar spinal stenosis (LSS). However, it is unknown whether amino acids and/or vitamin D are beneficial in older adults following lumbar surgery for LSS. PURPOSE: To evaluate whether branched-chain amino acids (BCAA) plus vitamin D supplementation could attenuate the loss of muscle mass and strength, accelerate the return of functional mobility, and improve clinical outcomes following lumbar surgery for LSS. STUDY DESIGN/SETTING: A single-center, single-blind randomized controlled trial. PATIENT SAMPLE: Eighty patients who received lumbar surgery for LSS. OUTCOME MEASURES: The primary outcome was the Zurich claudication questionnaire (ZCQ), and secondary outcomes included knee muscle strength, muscle mass measured by bioelectrical impedance analysis, gait speed and a timed up-and-go test (TUG) at 12 weeks postoperatively. Follow-up assessment was performed for the ZCQ at 52 weeks postoperatively. METHODS: Patients ingested the supplementation (BCAA group: BCAA plus vitamin D, Nonamino acid group: nonamino acid) twice daily for 3 weeks from the day after surgery, and received two hours of postoperative inpatient rehabilitation 5 times a week. RESULTS: No significant differences were observed in the mean changes on the ZCQ between the two groups at 12 weeks and 52 weeks. At 2 weeks postoperatively, the nonamino acid group showed significant deterioration compared with the BCAA group for strengths of knee extensor and knee flexor (p < .01). At 12 weeks, the BCAA group showed significant improvements in knee extensor strength and knee flexor strength compared with the nonamino acid group (p <.01). There were no significant differences in mean changes of muscle mass, maximum gait speed, and TUG at 12 weeks between two groups. CONCLUSIONS: BCAA plus vitamin D supplementation did not improve LSS-related clinical outcomes after lumbar surgery for LSS, even though muscle strength increased. Future studies should focus on long-term outcomes for muscle mass and physical function, including development of sarcopenia and frailty.

MRI grading of spinal stenosis is not associated with the severity of low back pain in patients with lumbar spinal stenosis.

BACKGROUND: Although lumbar spinal stenosis (LSS) often coexists with other degenerative conditions, few studies have fully assessed possible contributing factors for low back pain (LBP) in patients with LSS. The purpose of this study was to identify factors associated with the severity of LBP in patients with LSS. METHODS: The patients with neurogenic claudication caused by LSS, which was confirmed by magnetic resonance imaging (MRI) were included in this cross-sectional study. Data included ratings of LBP, buttock and leg pain, and numbness on a numerical rating scale (NRS), 36-item Short-Form Survey (SF-36) scores, muscle mass measured by bioelectrical impedance analysis, and radiographic measurements including lumbopelvic alignment and slippage. The severity of LSS, endplate defects, Modic endplate changes, intervertebral disc degeneration, and facet joint osteoarthritis were evaluated on MRI. Spearman correlation and multivariate linear regression analyses were used to examine the factors associated with the severity of LBP (NRS score). RESULTS: A total of 293 patients (135 male and 158 female, average age 72.6 years) were analyzed. LBP was moderately correlated with buttock and leg pain, and buttock and leg numbness. Significant but weak correlations were observed between LBP and body mass index, appendicular and trunk muscle mass, all domains of SF-36, pelvic tilt, total number of endplate defects and Modic endplate changes, and summary score of disc degeneration grading, but not severity or number of spinal stenoses. In the multivariate regression analysis, age, female sex, trunk muscle mass, diabetes, NRS buttock and leg pain, NRS buttock and leg numbness, SF-36 vitality, pelvic tilt, and total number of endplate defects were associated with the severity of LBP. CONCLUSIONS: Trunk muscle mass, lumbopelvic alignment, and endplate defects, but not severity of stenosis are partly associated with severity of LBP, but buttock and leg pain and buttock and leg numbness have strongest relationships with LBP in patients with LSS.

Supervised physical therapy versus surgery for patients with lumbar spinal stenosis: a propensity score-matched analysis.

BACKGROUND: Previous studies comparing surgical with nonsurgical treatment for lumbar spinal stenosis (LSS) reported that surgery is superior to nonsurgical treatments, but intensive and adequate volume of physical therapy were rarely performed. The purpose of this study was to compare the 1-year follow-up outcomes of patients with LSS treated with supervised physical therapy or surgery using propensity score-matched analysis. METHODS: A total of 224 patients with LSS who received supervised physical therapy (n = 38) or surgery (n = 186) were included, of which 66 were matched on baseline demographics, radiological findings, and patient-reported outcomes. The physical therapy group received supervised physical therapy twice weekly for 6 weeks. The physical therapy sessions included manual therapy, individually tailored exercises, cycling, and body-weight supported treadmill walking. The surgery group underwent decompression surgery with or without spinal fusion. A propensity score analysis was performed using a one-to-one nearest neighbor approach. RESULTS: The surgery group showed greater improvements in Zurich claudication questionnaire symptom severity and physical function, SF-36 physical functioning, bodily pain, and mental health, but had more severe stenosis and symptoms and mental health problems than the physical therapy group at baseline (P <  0.05). After propensity score matching, there were no significant differences in baseline characteristics, and all clinical outcomes at 1 year, except for a higher percentage of responders achieving minimum clinically important difference in the role-emotional subscale of SF-36 in the surgery group (P <  0.05). CONCLUSIONS: When baseline characteristics were considered, supervised physical therapy yielded similar effects to lumbar surgery. These results suggest that supervised physical therapy is preferred over surgery as first-choice treatment, to prevent complications and to minimize health care costs, especially in mild to moderate cases of LSS.

Associations between psychological factors and daily step count in patients with lumbar spinal stenosis.

BACKGROUND: Body mass index, pain, female sex, and age have been reported as predictors of physical activity in patients with lumbar spinal stenosis (LSS). However, no reports have examined the psychological factors associated with physical activity in people with LSS. PURPOSE: To use psychological assessments to identify the factors associated with physical activity measured as daily step count in people with LSS. METHODS: Seventy-one patients who received outpatient physical therapy were included. All patients completed the following scales at baseline: Zurich Claudication Questionnaire; self-paced walking test (SPWT); numerical rating scale of low back pain, leg pain, and leg numbness; Hospital Anxiety and Depression Scale (HADS); Pain Catastrophizing Scale; Pain Anxiety Symptoms Scale (PASS-20); and Tampa Scale for Kinesiophobia. Physical activity was measured using a pedometer as the average number of daily steps. RESULTS: Daily step count was significantly associated with age, number of stenoses, severity of stenosis at L3-L4, walking distance on the SPWT, PASS-20 total score, cognitive anxiety, escape/avoidance, fear, and HADS depression score (p < .05). Multiple regression analysis showed that age, severity of stenosis at L3-L4, walking distance on the SPWT, and PASS-20 fear predicted daily step count (r2 = 0.414). CONCLUSION: Older age, fewer stenoses, less severe stenosis at L3-L4, lower walking capacity, higher anxiety, and fear-avoidance beliefs about pain and depression are more closely associated with lower daily step count than are back and leg pain. Assessment and treatment of psychological factors might help to increase physical activity in patients with LSS.

Supervised physical therapy versus unsupervised exercise for patients with lumbar spinal stenosis: 1-year follow-up of a randomized controlled trial.

OBJECTIVE: To compare the 1-year outcomes of patients with lumbar spinal stenosis treated with supervised physical therapy or unsupervised exercise. DESIGN: A single-center randomized controlled trial with concealed allocation, blinded assessor and intention-to-treat analysis. SETTING: Spine care center. SUBJECTS: A total of 86 patients presenting with symptoms of neurogenic claudication caused by lumbar spinal stenosis. INTERVENTIONS: The physical therapy group received supervised physical therapy sessions twice a week for 6 weeks and home exercise program. The home exercise group received 6-week home exercise program only. MAIN MEASURES: The primary outcome was symptom severity on the Zurich claudication questionnaire at 1 year. Secondary outcomes included physical function, pain, health-related quality of life and the surgery rate after 1 year. RESULTS: At 1 year, more patients in the physical therapy group than in the home exercise group achieved minimum clinically important differences in Zurich claudication questionnaire symptom severity (60.5% vs 32.6%; adjusted odds ratio [AOR] 4.3, [95% CI [1.5-12.3], P = 0.01); Zurich claudication questionnaire physical function (55.8% vs 32.6%; AOR 3.0 [1.1-8.1], P = 0.03); SF-36 bodily pain (48.8% vs 25.6%; AOR 2.8 [1.1-7.3], P = 0.03), and SF-36 general health (20.9% vs 7.0%; AOR 6.1 [1.1-33.0], P = 0.04). The surgery rate at 1 year was lower in the physical therapy than in the home exercise group (7.0% vs 23.3%; AOR 0.2 [0.04-0.9] P = 0.04). CONCLUSIONS: Supervised physical therapy produced greater improvements in symptom severity and physical function than unsupervised exercise and was associated with lower likelihood of receiving surgery within 1 year.

Influence of Sarcopenia on the Effect of Exercise Therapy for Elderly Patients with Chronic Low Back Pain.

INTRODUCTION: Sarcopenia, a condition characterized by decreased skeletal muscle mass, has increasingly been attracting attention in Japan, which has an aged society. The association between chronic low back pain (CLBP) and muscle mass is important. This study aimed to investigate the effect of exercise therapy for CLBP with or without sarcopenia. METHODS: This study was a prospective cohort study. Patients who were aged >65 years during 2017-2018 and had CLBP, with pain lasting >12 weeks and pain intensity being ≥3, were included in the study. The patients were divided into two groups: sarcopenia (S) and nonsarcopenia (NS) groups. The numerical rating scale (NRS) for pain intensity, Roland-Morris Disability Questionnaire (RMDQ), Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), Hospital Anxiety and Depression Scale (HADS), trunk muscle strength, a European Quality of Life instrument, and an NRS of treatment satisfaction were assessed. All patients underwent a high-intensity exercise therapy during 2 weeks of hospitalization and were followed up for 1 and 3 months. RESULTS: Twenty-eight patients with CLBP were included. The prevalence rate of sarcopenia was 42.9%. The NRS and RMDQ scores and gait function were clinically improved at the end points in all patients with or without sarcopenia. Moreover, high treatment satisfaction was achieved. The quality of life, treatment satisfaction, psychological disorder subscale score of the JOABPEQ, and HADS score tended to be lower in the S group than in the NS group. CONCLUSIONS: Our short-term exercise therapy was effective for low back pain, disability, and gait disturbance in elderly patients with CLBP with or without sarcopenia. However, the prevalence of sarcopenia was high in elderly patients with CLBP. Although low back pain and disability in patients in the S group were improved by exercise therapy, their quality of life and treatment satisfaction might be lower than those of patients without sarcopenia.

Clinical Features of Sarcopenia in Patients With Lumbar Spinal Stenosis.

STUDY DESIGN: Cross-sectional design. OBJECTIVE: To investigate the prevalence of sarcopenia and identify factors associated with sarcopenia in patients with lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: Patients with LSS have a higher prevalence of sarcopenia compared with healthy older adults. However, the clinical features of sarcopenia in patients with LSS are poorly understood and the factors affecting sarcopenia in patients with LSS remain unclear. METHODS: Patients diagnosed with LSS based on clinical examination and magnetic resonance imaging findings, and referred to physical therapy, were enrolled. Muscle mass was measured using bioelectrical impedance using InBody S10. We collected a numerical rating scale (NRS) for back pain, the 36-Item Short-Form Survey (SF-36), the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), bone mineral density (BMD), and radiographic measurements of spinal alignment. Sarcopenia was defined according to the Asian Working Group for Sarcopenia guidelines and patients were classified into sarcopenia or nonsarcopenia groups. RESULTS: A total of 178 patients were enrolled: 35 in the sarcopenia group and 143 in the nonsarcopenia group. The prevalence of sarcopenia was 19.7%. The average percent of slip (% slip) among patients in the sarcopenia group was significantly higher compared with those in the nonsarcopenia group (P < 0.05). Body mass index (BMI), BMD, physical function as assessed by the SF-36, and gait disturbance as assessed by the JOABPEQ were significantly lower in the sarcopenia group compared with those in the nonsarcopenia group (P < 0.05). A trend was observed toward between-group differences in back pain on the NRS (P < 0.1). In the logistic regression analysis, significant associations were seen between sarcopenia and % slip (odds ratio 1.15, 95% CI 1.01-1.30). CONCLUSION: Patients with LSS and sarcopenia have a higher degree of slippage and lower BMI, BMD, and physical function, and reported more severe low back pain, compared with those without sarcopenia. LEVEL OF EVIDENCE: 4.

Therapeutic Advantages of Frequent Physical Therapy Sessions for Patients With Lumbar Spinal Stenosis.

STUDY DESIGN: A retrospective study of a randomized clinical trial and a prospective study of patients with lumbar spinal stenosis (LSS). OBJECTIVE: The aim of this study was to identify the effects of the number of physical therapy (PT) sessions on clinical outcomes of patients with LSS. SUMMARY OF BACKGROUND DATA: Supervised PT for patients with LSS has been reported to lead to better short-term outcomes in terms of disability and leg pain than unsupervised exercise. However, no studies have investigated the relationship between the number of PT sessions and the therapeutic effects in patients with LSS. METHODS: All patients received exercise therapy for 6 weeks. Included were 43 patients receiving supervised PT twice a week (P2 group), 38 patients receiving supervised PT once a week (P1 group), and 43 patients receiving a home exercise program alone (HE group). Clinical outcomes were measured using the Zurich Claudication Questionnaire (ZCQ), a numerical rating scale (NRS) of back pain and leg pain, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) at baseline and at 6 weeks. RESULTS: At 6 weeks, the P2 group showed significant improvements in ZCQ physical function, back and leg pain on the NRS compared with the P1 group (P < 0.05). Compared with the HE group, the P2 group showed significant improvements in ZCQ symptom severity and physical function, back and leg pain on the NRS, and JOABPEQ gait disturbance (P < 0.05). There were no significant differences in mean changes after 6 weeks between the P1 and HE groups. CONCLUSION: Six weeks of supervised PT twice a week resulted in significant short-term improvements in symptom severity, physical function, back and leg pain, and gait disturbance compared with once a week and/or home exercise alone. Patients with LSS should be treated with intensive and supervised exercise programs to obtain maximum benefit of exercise therapy. LEVEL OF EVIDENCE: 3.

Supervised physical therapy vs. home exercise for patients with lumbar spinal stenosis: a randomized controlled trial.

BACKGROUND CONTEXT: Exercise has been reported to improve short-term outcomes for patients with LSS in terms of disability and back and leg pain. However, no studies have compared supervised exercise with unsupervised exercise or quantified physical activity using a pedometer to confirm compliance with a home exercise program. PURPOSE: To compare the effectiveness of supervised physical therapy (PT) with unsupervised exercise for patients with lumbar spinal stenosis (LSS). STUDY DESIGN/SETTING: A single-center, open-label, randomized controlled trial. PATIENT SAMPLE: Patients presenting with symptoms of neurogenic claudication caused by LSS, which was confirmed by magnetic resonance imaging. OUTCOME MEASURES: The primary outcome was improvement in symptom severity scores on the Zurich Claudication Questionnaire (ZCQ) at 6 weeks. Secondary outcomes included physical function on the ZCQ, self-paced walking test (SPWT) performance, pain indicated using a numerical rating scale (NRS), and the number of daily steps measured by pedometer. METHODS: Patients with LSS were randomized to a PT group, who performed supervised PT twice a week for 6 weeks, or a home exercise (HE) group. PT sessions included manual therapy, individually tailored stretching and strengthening exercises, cycling, and body weight-supported treadmill walking. RESULTS: Forty-three patients were randomly allocated to the PT group and 43 patients to the HE group. Compared with the HE group, the PT group had greater percentage of responders achieving minimum clinically important difference in ZCQ symptom severity (difference for percentage between groups [95%confidence interval], 30.2% [9.1-48.6], p=.01), ZCQ physical function (32.6% [11.6-50.6], p<.01), walking distance on the SPWT (39.5% [18.8-56.7], p<.01), leg pain on the NRS (34.9% [13.9-52.7], p<.01), and number of daily steps (25.6% [4.9-43.9], p=.01). CONCLUSIONS: Supervised PT for patients with LSS resulted in significant short-term improvements in symptom severity, physical function, walking distance, pain, and physical activity compared with unsupervised exercise.

A comparative study of 2-year follow-up outcomes in lumbar spinal stenosis patients treated with physical therapy alone and those with surgical intervention after less successful physical therapy.

BACKGROUND: The efficacy of physical therapy for patients with lumbar spinal stenosis (LSS) has been reported only for the short term, and few reports have compared outcomes of surgical treatment with nonsurgical treatment after physical therapy. The purpose of this study was to assess 2-year outcomes of LSS patients treated with surgery or under follow-up observation after physical therapy for 6 weeks. METHODS: Patients presenting with neurogenic claudication, radiologically-confirmed central LSS affecting both legs and refractory symptoms to pharmacotherapy of more than 3 months were enrolled. Patients were treated with manual therapy, stretching and strengthening exercises, and body weight-supported treadmill walking once a week for 6 weeks. Clinical outcomes were measured using the Zurich Claudication Questionnaire (ZCQ), visual analog scale of low back pain, leg pain, and numbness, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire and the SF-36. Two years after physical therapy, patients were classified into the observation group (Group I) or the surgery group (Group II), whose patients failed to respond to physical therapy and wanted to undergo surgery. RESULTS: Thirty-eight patients were enrolled; 28 had complete data at 2 years: 21 and 7 in Groups I and II, respectively. Group II had a higher body mass index (BMI) than Group I. There were no significant differences in clinical outcomes at baseline. Six weeks after physical therapy, Group I had significantly better outcomes for symptom severity and physical function on the ZCQ subscales, physical functioning and bodily pain on the SF-36 subscales. These outcomes in Group I were maintained or improved and did not differ significantly between groups at 2-years. However, the physical function on the ZCQ subscales was improved in Group II more than those in Group I (mean difference -0.6; 95% CI: -1.2 to -0.03, P < 0.05) at 2 years. CONCLUSIONS: At 2 years, the outcomes except for the change in physical function score in the ZCQ subscale did not differ significantly between patients who had undergone surgery and those who avoided surgery.