Myofascial Pain and Failed Back Surgery

The failure rate of surgery for low back pain is very high. On average, about 53 percent of all L5-S1 disc surgeries fail to produce relief of symptoms.¹ Quite frequently, the patient ends up in worse shape than before the operation. One common reason for failure is lack of the proper indication for surgery.² Current estimates suggest that 90-97 percent of all low back/leg pain is caused by dysfunction of either the spinal joints or muscles, or both.^3,4 Low back/leg syndromes as caused by the subluxation complex can easily be mistaken for disc and/or instability syndromes by physicians who may not be trained to diagnose functional pathologies of the locomotor system.

There are several muscles that can cause pain in the lower back and leg when they develop trigger points (TPs). One common example is the quadratus lumborum. This muscle is a major lateral flexor of the spine and can cause pain in the hip area over the iliac crest and greater trochanter, as well as in the buttock and over the SI joint.⁵ The pain can be aggravated by coughing and sneezing because of its role as a stabilizer of the lower ribs during forced expiration,⁶ and due to this can be mistaken for a root syndrome. The gluteus minimus TP can refer pain into the buttock area and straight down the back of the leg to the calf.⁷ This may often be seen in failed back surgery syndromes as many times the surgery is performed for the sole reason that there is pain radiating down the leg. If the TP is located in the anterior aspect of the muscle, pain can refer down the side of the leg to the ankle. This has been diagnosed by some physicians as sciatica (believe it or not), causing DeFranca to jokingly coin the term "side-atica."⁸

The piriformis TP syndrome patient is perhaps the one most commonly misdiagnosed as suffering from a root syndrome, as this not only refers pain down the back of the leg, but it can also cause paresthesias in the leg. This occurs because the sciatic nerve pierces the piriformis in a small percentage of patients and shortening of the muscle due to the trigger point can cause irritation and compression of the nerve.^7,9 Also, straight leg raise is often positive in these patients.

Chiropractic evaluation in patients who have had failed back surgery is extremely important, as many times the residual pain has its origin in the subluxation complex. With adequate treatment, a large percentage of these patients can experience significant pain relief, and sometimes complete recovery.

References

1. Radin, E.L. "Reasons for failure of L5-S1 intervertebral disc excisions." International Orthop 1987; 11:255-259.

    

2. Tilscher, H.; Hanna, M. "Causes of poor results of surgery in low back pain." Man Med 1990; 5(3):110-114.

    

3. Rosomoff, H. "Lecture at American Back Society Symposium, Orlando, May, 1988.

    

4. Kirkaldy-Willis. Managing Low Back Pain, 2nd ed. Churchill Livingtone, New York, 1988.

    

5. Simons, D.G.; Travell, J.G. "Myofascial origins of low back pain 2: Torso muscles." Postgrad Med 1983; 73(2):74-83.

    

6. Basmajian, J.V.; DeLuca,C.J. Muscles Alive: Their Functions Revealed Through Electromyography, 5th ed. Williams and Wilkens, Baltimore, 1985.

    

7. Simons, D.G.; Travell, J.G.; "Myofascial origins of low back pain 3: Pelvic and lower extremity muscles." Postgrad Med 1983; 73(2):84-108.

    

8. DeFranca, G. Lecture at Low Back Pain '90 Symposium, East Rutherford. Sept. 1990.

    

9. Mennel, J.M. Trigger points in referred spinal pain. In: Grieve GPed. Modern Manual Therapy of the Vertebral Column. Churchill Livingstone, New York, 1986;250-258.