Benefit to Preserving Midline Structure in Lumbar Decompression?

A new study has concluded that there is NO benefit to preserving the midline structures for lumbar spinal stenosis—at least as compared to classic central decompression.

The study, “No Benefit with Preservation of Midline Structures in Decompression for Lumbar Spinal Stenosis,” was published in the April 2022 issue of the journal Spine.

“The classic surgical procedure for lumbar spinal stenosis is a central, facet joint sparing decompressive laminectomy. Alternative approaches have been developed to preserve the midline structures,” the study authors wrote.

The analysis included patients over the age of 50 years who underwent decompression surgery for lumbar spinal stenosis in the National Swedish Spine Registry from December 31, 2015, until October 6, 2017. The data was culled from surgeon reports and patient questionnaires before surgery and at two-years postop.

The primary outcome was the Oswestry Disability Index and secondary outcomes were the Numeric Rating Scale for leg and back pain, EuroQol-5 Dimensions, Global Assessment, patient satisfaction and rate of subsequent surgery.

Overall, the research team collected data for 2,974 patients who were treated with decompression laminectomy and 365 patients who had midline preserving surgery.

The researchers found that baseline scores were comparable between the groups. The mean improvement in Oswestry Disability Index Score at follow-up was 16.6 in the laminectomy group and 16.9 in the midline preserving surgery group.

The difference in improved Oswestry Disability score was 0.53 (95% confidence interval, CI -1.71 to 2.76; p = 0.64). The researchers calculated that 68.3% of the patients showed a decreases score of at least the defined minimal clinically importance difference after laminectomy and 67% did after preserving the midline structures (p = 0.73).

They also reported no significant differences in the improvement of Numeric Rating Scale for leg and back pain, EuroQol-5 Dimensions, Global Assessment or patient satisfaction. Additional surgeries were required for 5.5% of the laminectomy patients and 4.09% of the midline preserving surgery patients.

“In this study on decompression techniques for lumbar spinal stenosis, there was no benefit in preserving the midline structures compared to laminectomy 2 years after decompression. The conclusion is that the surgeon is free to choose the surgical method that is thought most suitable for the patient and the condition with which the patient presents,” the study authors concluded.

The study authors include Erik Elmqvist, M.D., of Visby Hospital, Visby, Sweden, and Lars Lindhagen and Peter Försth, M.D., Ph.D., both from Uppsala University, Uppsala, Sweden.