Faculty Bibliography

BACKGROUND:Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a well-accepted procedure for the treatment of degenerative lumbar disease. However, its ability to restore lumbar lordosis has been limited. Development of expandable lordotic interbody devices has challenged this limitation, furthering the scope of minimally invasive surgery. OBJECTIVE:To evaluate the radiographic and clinical effects of expandable lordotic interbody devices placed through an MIS-TLIF approach. METHODS:We conducted a retrospective review of 32 1-level and 18 2-level MIS-TLIFs performed using lordotic expandable interbody devices. Lumbar radiographic measurements, Oswestry Disability Index scores (ODI), and Visual Analogue Scale scores (VAS) were obtained at preoperative, 6 wk follow up, and last follow up time points. Last follow up occurred at a mean of 11.5 ± 7.6 mo (mean ± SD). RESULTS:At 6-wk follow-up, segmental lordosis, disc height, and foraminal height increased by an average of 3.4°, 6.4 mm, and 4.4 mm, respectively. Only the 2-level group showed a significant increase in lumbar lordosis of 5.8°. No significant changes occurred in sacral slope, pelvic tilt, or pelvic incidence. Average ODI and VAS decreased by -12.0 and -4.5, respectively. Postoperative lumbar lordosis inversely correlated with preoperative lordosis in patients with an initial Pelvic Incidence to Lumbar Lordosis mismatch (PI-LL) of >10°, (r = -0.5, P = .009). CONCLUSION:When applied across 2-levels, MIS-TLIF using expandable lordotic interbody devices produced a significant increase in lumbar lordosis. Preoperative lumbar lordosis was found to be a predictor of postoperative lumbar lordotic change in patients with sagittal imbalance.

This operative video is a detailed look at minimally invasive transforaminal lumbar interbody fusion. We provide a step-by-step guide with appropriate narration and operative video to enhance the educational experience. We review clinical and radiographic evaluation, patient positioning, intraoperative navigation, localization, percutaneous pedicle screw placement, minimally invasive approach, disc space preparation, placement of interbody device, and closure. By presenting up-to-date minimally invasive and intraoperative navigation techniques, this video provides educational benefit to all neurosurgeons regardless of training level.

BACKGROUND:Chordomas arise from remnants of the notochord and occur throughout the neuroaxis. En bloc resection of chordomas can prove especially challenging in the upper cervical spine secondary to the unique structural anatomy and intimate relationship to the vertebral arteries and spinal cord. CASE DESCRIPTION/METHODS:We describe the resection of a C2-C3 chordoma in a 55-year-old woman in 2-stage fashion with preservation of the vertebral arteries. First, a posterior instrumented fusion and removal of the posterior elements was performed, followed by an anterior transmandibular en bloc resection with cage reconstruction with kick-plate support achievable with off-the-shelf products. CONCLUSIONS:Chordomas in the upper cervical spine pose a surgical challenge but are amenable to en bloc resection. With careful planning and intraoperative adaptability, the surgeon can achieve a suitable reconstruction with off-the-shelf products.