Research Review By Dr. Ceara Higgins©

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Date Posted:

October 2019

Study Title:

Comparative Clinical Effectiveness of Nonsurgical Treatment Methods in Patients with Lumbar Spinal Stenosis: A Randomized Clinical Trial

Authors:

Schneider MJ, Ammendolia C, Murphy DR, et al.

Author's Affiliations:

University of Pittsburgh, Pennsylvania, USA; University of Toronto, Canada; Alpert Medical School of Brown University, Providence, Rhode Island, USA; University of Oklahoma Health Sciences Center, Oklahoma, USA; Virginia Polytechnic Institute and State University, Virginia, USA.

Publication Information:

JAMA Network Open 2019; 2(1): e186828. Doi:10.1001/jamanetworkopen.2018.6828

Background Information:

Lumbar spinal stenosis (LSS) is a degenerative condition of the spine, affecting 30% of older adults (1). LSS can cause significant functional limitation related to walking, disability, and increased risk of falling (2). This condition is often treated surgically, with the rate of complex spinal fusions in the United States increasing by 137% between 1998 and 2008 (3). These types of surgeries are costly, and come with risks, complications, and rehospitalizations (4).

This study aimed to compare the effectiveness of 3 nonsurgical interventions on symptoms, physical function, and physical activity in patients with LSS.

Pertinent Results:

Participant Characteristics:
Of 259 participants, 88 were randomly allocated to medical care, 84 to group exercise, and 87 to manual therapy/individualized exercise. The participants had an average age of 72.4, average body mass index of 31, an average of 4.7 medical comorbidities, an average baseline SSS score of 31.5 (out of a maximum of 55), and walked a median of 272.7 meters during the SPWT, indicating a moderate level of symptomatic LSS.

Treatment Outcomes:
Patients receiving manual therapy/individualized exercise showed greater reductions in SSS scores at 2 months when compared to medical care or group exercise, however, this did not reach the minimal clinically important difference (MCID). At 2 months, no between-group differences were found for physical activity and at 6 months, no between-group differences were found for any outcome measure. However, at 2 and 6 months, all groups showed within-group improvements in walking distance from a baseline range of 433.3-482.2 meters to a range of 683.3-723.5 meters at 6 months. That is a clinically important difference – a 42-67% improvement! Interestingly, participants only reported modest improvements on the SSS in self-reported symptoms and physical function despite these increases. It is possible that the SSS questionnaire is more responsive to the greater magnitude of change seen in patients undergoing spinal surgery or that self-reported data is simply not as accurate as a direct measurement of time and distance walked.

Adverse Reactions:
Individuals in the manual therapy/individualized exercise group had higher rates of transient muscle (54%) and joint (49%) soreness, and individuals in the medical care group had higher rates of gastrointestinal complaints (6%), drowsiness (6%), and dry mouth (5%). However, all adverse events were anticipated and resolved within 48 hours. There were no between-group differences in the number of self-reported falls or medical co-interventions between the end of care and 6-month follow-up. At 6 months, only 2-3% of the participants from each group reported having spinal surgery.

Clinical Application & Conclusions:

Current clinical guidelines provide little information about the effectiveness and safety of nonsurgical interventions for LSS, so the results of this study help to fill that void. Specifically, manual therapy/individualized exercise showed better short-term outcomes (2 months), but no intervention was superior at 6 months. However, all groups achieved clinically important improvements in walking distance at 2 and 6 months. This is especially important, as many LSS patients cite the inability to walk for any distance as their initial reason from seeking care (patient-specific outcome targeting!). It is interesting to note that the medical care group showed improvements in walking distance despite receiving no specialized exercise instruction. It is possible that the interventions all lead to reduced fear avoidance behaviour and/or passive coping, leading to increased patient self-confidence to attempt to walk farther.

As all of the studied interventions showed similar improvements, it may best serve patients if their health care professional discussed all of these therapeutic options with the patient as alternatives to surgical intervention. Manual therapy provided by a chiropractor or physiotherapist should be on the list of options discussed. This form of patient-centered care is especially important considering the mounting concerns about rising rates of spinal surgery and opioid use in older adults with LSS.

Study Methods:

These researchers performed a 3-arm, single-center randomized clinical trial where patients were randomly assigned to receive:
  1. medical care;
  2. group-based exercise; or
  3. manual therapy/individualized exercise
Interventions were all completed within 6 weeks and effectiveness and safety were assessed at 2 months (2 weeks after the end of care) and 6 months (4 months after end of care). Patients were recruited through postcard mailings, research registry, bus advertisements, health fairs, and advertisements in the Pittsburgh Senior News. It was not possible to blind treating clinicians or research participants, so the researchers attempted to minimize bias by having all baseline physical examinations and follow-up re-assessments performed by an independent physical therapist.

Inclusion criteria were as follows:
  • Previous diagnosis of LSS and ability to provide MRI or computed tomography evidence of the narrowing of the central canal, lateral recess, and/or foramen
  • The presence of at least one of: 1) leg symptoms worsened by walking and relieved by sitting; 2) symptoms worsened by lumbar extension and relieved by flexion; and/or 3) leg pain relieved by leaning forward on a shopping cart while walking
  • 60 years of age or older
  • Ability to read/write English
  • Ability to walk at least 15 meters without an assistive device
  • Limitations in walking due to LSS
  • Ability to engage in mild exercise
  • Willingness to be randomized
Exclusion criteria:
  • Previous surgery for LSS or lumbar fusion
  • Cauda equina symptoms
  • Inability to complete a self-paced walking test (SPWT) for any reason other than symptoms of LSS
  • Instructions from a physician not to engage in physical exercise
  • History of metastatic cancer
  • Severe peripheral artery disease or an ankle-brachial index of less than 0.8
  • Any neurologic disease other than LSS that affected their ability to walk
Interventions:
Patients were randomized using a web-based system immediately following baseline assessment. Patients in the medical care arm completed 3 visits with a physical medicine physician over the course of 6 weeks. Treatment primarily involved the prescription of oral medications including one or a combination of non-narcotic analgesics, anticonvulsants, and/or antidepressants. Physicians could also refer patients for epidural steroid injections in cases where patients showed inadequate pain relief with oral medications, had severe neurogenic claudication, or expressed a preference for injections. Patients were also given general guidance on gentle stretching and advised to stay active.

Patients in the group exercise arm participated in supervised exercise classes for older adults 2 times per week for 6 weeks, for a total of 12 exercise classes. Classes were about 45 minutes in length and were taught by instructors certified in senior fitness. Patients self-selected the intensity of their exercise class (easy to medium intensity) based on their own fitness level.

Patients in the manual therapy/individualized exercise arm received treatment from either chiropractors or physiotherapists who had been trained in a standardized treatment protocol. Treatment lasted about 45 minutes and were attended 2 times per week for 6 weeks. Each session included a warm-up procedure using a stationary bicycle, manual therapy procedures (including lumbar distraction mobilization, hip joint mobilization, side posture lumbar/sacroiliac joint mobilization, and neural mobilization), and individualized instruction in spinal stabilization exercises and home stretching.

Primary outcomes included: 1) patient-reported symptoms and physical function as measured on the 12-item Swiss Spinal Stenosis questionnaire (SSS - includes a 7-item symptom severity subscale and a 5-item physical function subscale – with higher scores indicating higher levels of disability); and 2) walking performance, as measured on the self-paced walking test (SPWT). The SPWT involves participants walking on a level surface until their LSS symptoms force them to stop and sit to rest. The distance and time walked are recorded to a 30-minute maximum. The secondary outcome was a measurement of daily physical activity based on data from an armband accelerometer worn 24 hours per day for 7 days. Daily minutes spent in activity measured at greater than 1.5 metabolic equivalent of task units were measured and the average value used. Rates of attrition, adherence to assigned treatment, adverse events, self-reported falls, and co-interventions were also tracked.

Study Strengths / Weaknesses:

Strengths:
  • Group exercise classes are often available to older adults through community centers at little or no cost, making this treatment option very accessible.
  • The manual therapy/individualized exercise protocol could be implemented by chiropractors and physiotherapists with minimal training.
Weaknesses:
  • A higher number of participants withdrew from the group exercise intervention immediately following randomization compared to the other groups. This may have created a selection bias, as the individuals remaining in the group exercise arm may have been more motivated toward that type of therapy than participants in the other 2 arms.
  • Participants in the manual therapy/individualized exercise group spent about 45 minutes one-on-one with a chiropractor or physiotherapist at each session. This increased personal attention may have affected the results and increased patients’ perception of short-term improvement in self-reported pain and function.
  • It is not possible to determine any individualized treatment effect of manual therapy or individualized exercise as the treatment protocol combined these treatments.
  • Due to the lack of a no-treatment group, it is not possible to rule out improvement due to natural history

Additional References:

  1. Kalichman L, Cole R, Kim DH, et al. Spinal stenosis prevalence and association with symptoms: the Framingham Study. Spine J 2009; 9(7): 545-550.
  2. Winter CC, Brandes M, Muller C, et al. Walking ability during daily life in patients with osteoarthritis of the knee or the hip and lumbar spinal stenosis: a cross sectional study. BMC Musculoskelet Disord 2010; 11: 233.
  3. Taylor VM, Deyo RA, Cherkin DC, et al. Low back pain hospitalization: recent United States trends and regional variations. Spine (Phila Pa 1976) 1994; 19(11): 1207-1212.
  4. Kim CH, Chung CK, Park CS, et al. Reoperative rate after surgery for lumbar spinal stenosis without spondylolisthesis: a nationwide cohort study. Spine J 2013; 13(10): 1230-1237.