Lumbar discectomy benefits seen eight years postop

Surgical patients reported significantly less leg pain and a smaller Oswestry score than those who received conservative treatment.

NEW YORK — Six-year outcomes of a randomized trial in Finland showed that patients with sciatica who received a lumbar microdiscectomy experienced significantly less pain and disability than patients who received conservative treatment.

Investigators also found that the benefits of surgery lasted more than eight years in some cases.

Comparative studies on the effectiveness of lumbar discectomy are scarce, noted lead investigator Heikki Österman, MD, of the ORTON Orthopaedic Hospital of the Invalid Foundation in Helsinki. “This is one of the reasons why we wanted to look at this ... to see how it [compared] with conservative treatment over several years,” he said.

Österman, who presented his findings at the International Society for the Study of the Lumbar Spine 32nd Annual Meeting, performed a randomized trial comparing microdiscectomy to continued conservative therapy in 20- to 50-year old patients with sciatica of six to 12 weeks duration. All patients demonstrated clinical findings of nerve root compression and radiologically confirmed herniation of the nucleus pulposus (extrusion or sequester), Österman said.

The researchers randomized 56 patients; all 28 patients in the microdiscectomy group underwent surgery for L4-L5 disc herniations.

Early results

The initial follow-up was two years. “Our two-year statistics showed that microdiscectomy patients did well at follow-up and they were highly satisfied with the active treatment,” he said. “Other than that, there were no big differences between the two groups."

“We then mailed a questionnaire at a mean follow-up of six years [range five to eight years], where we inquired about patients’ leg and back pain and overall disability,” Österman added. Intensity of leg pain (100 mm Visual Analog Scale, or VAS) was the primary outcome measure. Secondary outcomes included back pain (100 mm VAS) and the Oswestry disability index.

Investigators analyzed the results on an intention-to-treat basis.

Forty-five patients (80%) responded to the questionnaire. Discectomy patients ultimately reported less leg pain and less back-related disability, he said. “The differences were statistically significant, and at least for back pain and Oswestry, they can be considered statistically significant as well.”

Leg pain patterns

Patients were also asked about the patterns of their leg pain. One patient in the discectomy group and four patients in the control group with conservative treatment reported consistent leg pain. Nine patients in the discectomy group and 15 patients in the control group reported initial disappearance of the leg pain. Thirteen patients in surgery and six in the control group reported full disappearance of the leg pain without doing a follow-up.

Nineteen patients in the discectomy group also reported they resumed their normal work schedule and six said they had to do some modifications to accommodate their back pain.

Eleven of the 28 patients treated with conservative treatment eventually crossed over to surgery because of “unrelenting or recurring pain” or progressive neurological deficit, the investigators said.

“Our early results suggest that microdiscectomy seems to be associated with better overall improvement and better restoration of improvement” based on the 100-point VAS scale, Österman said. “The clinical results were very stable and convincing.”

For more information:
Österman H, Seitsalo S, Malmivaara A. Six-year outcomes of lumbar microdiscectomy. Results of a randomized controlled trial. Presented at the International Society for the Study of the Lumbar Spine 32nd Annual Meeting. May 10-14, 2005. New York.