Lumbar spinal stenosis (LSS) is a common reason for spine surgery. Several non-surgical LSS treatment options are also available, but their effectiveness remains unproven. The objective of this study was to explore the comparative clinical effectiveness of three non-surgical interventions for patients with LSS:
- medical care,
- group exercise,
- individualised exercise plus manual therapy.
All interventions were delivered during 6 weeks with follow-up at 2 months and 6 months at an outpatient research clinic. Patients older than 60 years with LSS were recruited from the general public. Eligibility required anatomical evidence of central canal and/or lateral recess stenosis (magnetic resonance imaging/computed tomography) and clinical symptoms associated with LSS (neurogenic claudication; less symptoms with flexion). Analysis was intention to treat.
Medical care consisted of medications and/or epidural injections provided by a physiatrist. Group exercise classes were supervised by fitness instructors. Manual therapy/individualized exercise consisted of spinal mobilization, stretches, and strength training provided by chiropractors and physical therapists. The primary outcomes were between-group differences at 2 months in self-reported symptoms and physical function measured by the Swiss Spinal Stenosis questionnaire (score range, 12-55) and a measure of walking capacity using the self-paced walking test (meters walked for 0 to 30 minutes).
A total of 259 participants were allocated to medical care (n = 88), group exercise (n = 84), or manual therapy/individualized exercise (n = 87). Adjusted between-group analyses at 2 months showed manual therapy/individualized exercise had greater improvement of symptoms and physical function compared with medical care or group exercise. Manual therapy/individualized exercise had a greater proportion of responders (≥30% improvement) in symptoms and physical function (20%) and walking capacity (65.3%) at 2 months compared with medical care (7.6% and 48.7%, respectively) or group exercise (3.0% and 46.2%, respectively). At 6 months, there were no between-group differences in mean outcome scores or responder rates.
The authors concluded that a combination of manual therapy/individualized exercise provides greater short-term improvement in symptoms and physical function and walking capacity than medical care or group exercises, although all 3 interventions were associated with improvements in long-term walking capacity.
In many ways, this is a fairly rigorous study; in one important way, however, it is odd. One can easily see why one group received the usual standard care (except perhaps for the fact that standard medical care should also include exercise). I also understand why one group attended group exercise. Yet, I fail to see the logic in the third intervention, individualised exercise plus manual therapy.
Individualised exercise is likely to be superior to group exercise. If the researchers wanted to test this hypothesis, they should not have added the manual therapy. If they wanted to find out whether manual therapy is better that the other two treatments, they should not have added individualised exercise. As it stands, they cannot claim that either manual therapy or individualised exercise are effective (yet, I am sure that the chiropractic fraternity will claim that this study shows their treatment to be indicated for LSS [three of the authors are chiropractors and the 1st author seems to have a commercial interest in the matter!]).
Manual therapy procedures used in this trial included:
- lumbar distraction mobilization,
- hip joint mobilization,
- side posture lumbar/sacroiliac joint mobilization,
- and neural mobilization.
Is there any good reason to assume that these interventions work for LSS? I doubt it!
And this is what makes the new study odd, in my view. Assuming I am correct in speculating that individualised exercise is better than group exercise, the trial would have yielded a similarly positive result, if the researchers had offered, instead of the manual therapy, a packet of cigarettes, a cup of tea, a chocolate bar, or swinging a dead cat. In other words, if someone had wanted to make a useless therapy appear to be effective, they could not have chosen a better trial design.
And why do I find such studies objectionable?
Mainly because they deliberately mislead many of us. In the present case, many non-critical observers might conclude that manual therapy is effective for LSS. Yet, the truth could well be that it is useless or even harmful (assuming that the effect size of individualised exercise is large, adding a harmful therapy would still render the combination effective). To put it bluntly, such trials
- could harm patients,
- might waste money,
- and hinder progress.