Lumbar spinal stenosis (stenosis of the low back) is a common cause of back problems in adults over 55 years old. Spinal stenosis describes a clinical syndrome of back, buttock, and/or leg pain. It is a condition in which the nerves in the spinal canal are closed in or compressed.
The spinal canal is the hollow tube formed by the bones of the spinal column. Anything that causes this bony tube to shrink can squeeze the nerves inside. As a result of many years of wear and tear on the parts of the spine, the tissues nearest the spinal canal sometimes press against the nerves.
In the lumbar spine, the spinal canal usually has more than enough room for the spinal nerves. The canal is normally 17 to 18 millimeters around, slightly smaller than a penny. Spinal stenosis develops when the anteroposterior diameter (front-to-back measurement of the canal) shrinks to 12 millimeters or less. Stenosis can also occur when the transverse diameter (side-to-side opening) is less than 15 millimeters.
Because this can be a painful and limiting condition, health care specialists are actively studying ways to treat it effectively without surgery. Conservative (nonoperative) treatment options include exercise, physical therapy, antiinflammatory drugs, pain relievers, or epidural steroid injections (ESI).
The spinal cord is covered by a material called the dura. The space between the dura and the spinal column is called the epidural space. It is thought that injecting steroid medication into this space fights inflammation around the nerves, the discs, and the facet (spinal) joints. This can reduce swelling and give the nerves more room inside the spinal canal.
In this study, the results of steroid injections were compared against one type of physical therapy intervention. Three groups of patients were compared. All 29 patients had a diagnosis of lumbar spinal stenosis but were in otherwise good health without heart disease, diabetes, past history of spine surgery, or recent episodes of vertebral fracture.
Everyone in all three groups was given a home exercise program and a drug called Voltaren (diclofenac) for pain control. Even though the authors recognized that adding this to the daily program might change their results, they did not think it would be ethical to keep patients from exercising or getting some pain relief from a drug known to help.
By putting everyone on the same base program, they could at least keep the groups consistent and test other variables. The disadvantage of this method is that there is always a potential that the exercise and pain relievers could interact with one of the other treatment methods and change the results. Special mathematical formulas were used to help eliminate this factor in the final analysis.
Of the three groups, the first group participated in a daily physical therapy program for two weeks. A combination of ultrasound, hot packs, and TENS (transcutaneous electrical nerve stimulation) was used in the treatment. Group two got one epidural steroid injection. The drug was administered via fluoroscopy (real-time X-ray) to the most stenotic (narrowed) area of the lumbar spine. The third group served as the control. They did just the baseline exercise and pain control measures.
Results were measured in terms of pain, physical mobility, and function. Specific tools used to measure these parameters included the visual analog scale (VAS), finger-to-floor distance, treadmill walk test, sit-to-stand, and the weight-carrying (WC) test.
Everyone in all three groups had significant pain relief. Patients in groups one and two had more improvement in pain and function than the control group. Their pain relief lasted at least six months (follow-up period). The effectiveness of steroid injections and physical therapy as tested here was equal in reducing pain and improving function. Outcomes suggest that treatment with either steroid injection or physical therapy is better than doing nothing.
But the authors point out several problems with their own study. First, it’s been clearly shown by other researchers that single epidural steroid injections (ESI) work best in the short run. Second, comparing ESI to physical therapy isn’t easy. There are many different kinds of physical therapy treatments available. The methods used in this study are considered passive. Using ultrasound as reported in this study and hot packs (two forms of heat) are not best practice when treating conditions that potentially involve local inflammation.
Third, physical therapy treatment was only given for two weeks. A longer treatment period might have made a greater difference. The authors conclude that further research is needed before declaring one treatment modality more effective than the other.