Transtubular Microscopic Far Lateral Lumbar Foraminotomy for Acute Disc Herniation Compared to Spondylotic Stenosis

Introduction: Transtubular microscopic far lateral lumbar foraminotomy is a well-known technique for treatment of radiculopathy secondary to extraforaminal lumbar disc herniation. Spondylotic stenosis secondary to facet arthropathy can also cause extraforaminal nerve compression, but surgical treatment frequently involves lumbar decompression and fusion rather than decompression alone. There is limited data evaluating the effectiveness of far lateral foraminotomy for the treatment of lateral nerve root compression secondary to spondylotic stenosis compared to acute disc herniation.

Methods: We performed a retrospective analysis of consecutive patients with lumbar extraforaminal nerve root compression treated with transtubular microscopic far lateral foraminotomy at a single ambulatory surgery center. Surgeries were performed between 2012 and 2023 by two experienced surgeons. Data was collected by retrospective chart review and patient survey. Univariate and multivariate analyses were performed.

Results: Among 190 patients, 118 were treated for acute disc herniation while 72 were treated for spondylotic stenosis. Within subjects paired t-tests for each cohort demonstrated significant improvement from baseline to 3-month, all at p<.001. That improvement was maintained at 1-year as all baseline to 1-year comparisons were significant at p<.001. 1-year satisfaction was not significantly different between the two cohorts (83.8% vs. 78.3%, p = 0.349). The Long-Rank (Mantel-Cox) test was not significant when comparing the estimated median time to return to work between the two cohorts.

Conclusion : Far lateral nerve root compression is a less common but important cause of back and leg pain that can be caused by acute disc herniation as well as spondylotic disease. Our study found that nerve root compression secondary to both pathologies can be treated by transtubular microscopic far lateral foraminotomy with significant post-operative improvement. At our institution, we have expanded our surgical indication for far lateral transtubular lumbar foraminotomy to include patients with purely spondylotic extraforaminal stenosis. Future studies are needed to define best patient selection.