Microdiscectomy for lumbar herniated nucleus pulposus led to low rate of fusion

Identifying preoperative factors may help determine patients who may experience recurrent herniation.

Sheeraz A. Quereshi

Patients with a symptomatic, single-level, lumbar herniated nucleus pulposus had a low likelihood of requiring fusion after they underwent microdiscectomy, according to results published in Global Spine Journal.

“In the long-term, in our study we found [microdiscectomy] was certainly a trend towards a reduction in the need for fusion at the index level,” Sheeraz A. Qureshi, MD, associate attending at Hospital for Special Surgery and minimally invasive spine surgeon at Weill Cornell Medical College, told Orthopedics Today. “I have a feeling if we look at it even further out and with more patients, we are going to see that trend become a significant finding in terms of statistical significance.”

Low fusion rates

In a retrospective review of 174 patients with symptomatic single-level lumbar herniated nucleus pulposus (NP) who underwent microdiscectomy either through a mini-open approach (n=39) or a minimally invasive dilator tube (n=135), Qureshi and his colleagues found no statistically significant differences in the rate of revision microdiscectomy based on surgical approach. Patients who underwent open microdiscectomy had a 10.3% rate of requiring index level fusion vs. a 4.44% rate in the minimally invasive group. Results also showed no statistical difference in time to fusion between the two groups.

“If you have minimally invasive surgery done for a microdiscectomy, then you are not going to be at a higher risk of needing a second surgery for another herniated disc and you may actually be at a lower risk of eventually needing a fusion. But, the percentages of all comers, whether it be minimally invasive or open, … are low overall,” Qureshi said.

Smoking status and revision microdiscectomy statistically predicted the need for eventual index level fusion after lumbar microdiscectomy in both groups, according to the multivariate regression analysis.

Finding ways to preserve motion

Qureshi said he found the low rate of patients who required fusion after open or minimally invasive microdiscectomy was surprising because he anticipated it would be higher.

“A lot of times we are on the fence in terms of what we should do for a given situation. To me the findings suggest it is absolutely worthwhile, if you are on the fence, to lean toward a microdiscectomy vs. immediately going to a fusion because we are giving the patient a high chance in terms of percentages that they might not need a fusion in the future,” he said.

These findings have led Qureshi and his colleagues to continue researching the best ways to preserve motion in patients with a herniated lumbar NP and to perform a fusion minimally invasively, if needed.

“My thoughts around the next step for a project like this is to start to collect more prospective data, which we have been, on our microdiscectomy patients,” Qureshi said.

From there, the goal, he said, would be to determine whether the patients with recurrent herniation who required another surgery or fusion were different in some respect from those who did not. He said he and his colleagues seek a preoperative factor, such as a score based on the patient’s MRI, location of the pathology, type of symptoms the patient is having, they can use to individualize what is most likely to happen in each patient. – by Casey Tingle

Reference:

McAnany SJ, et al Global Spine J. 2018;doi:10.1177/2192568217718818.

For more information:

Sheeraz A. Qureshi, MBA, MD, can be reached at 523 E. 72nd St., 9th Fl., New York, NY 10021; email: ironsm@hss.edu.

Disclosure: Qureshi reports no relevant financial disclosures.