gms | German Medical Science

Objective: The lateral transpsoas approach (XLIF/LLIF) is commonly used for lumbar interbody fusion and usually combined with dorsal instrumentation, requiring repositioning of the patient inbetween procedures from lateral to prone. In addition, lateral positioning has made the application of neuronavigation difficult in conventional XLIF technique and, thus, not been established. The aim of our case series was to investigate whether a navigated single prone position approach for XLIF and dorsal instrumentation is feasible and exploit its limitations and possible advantages compared to the conventional technique.

Methods: We established the technique in three pilot patients indicated for XLIF surgery in an observational prospective case series (nXLIF). In prone position a 3D-scan was performed (Siemens, Arcadis Orbic). At first dorsal pedicle screws were placed in order to avoid a navigation mismatch subsequent to XLIF. Afterwards the lateral retroperitoneal transpsoas approach for XLIF was performed with the surgeon sitting and using navigated instruments (Brainlab ®, NuVasive ® XLIF tubular retractors placed exactly parallel to the disc space) under intraoperative neurophysiological monitoring. Lastly, the rods were implanted and fixated. The duration, blood loss and xray exposure was compared to the standard procedure with a retrospective cohort of seven patients with monosegmental and four with bisegmental XLIF.

Results: The single prone position nXLIF was found to be a feasible approach for XLIF and subsequent dorsal instrumentation. The overall operation time (mean 125 ± 4,24 min) was shorter than in the conventional comparison groups (220 ± 96,42 for monosegmental and 370 ± 198,63 min for bisegmental fusion). In the conventional XLIF group, repositioning seemed to be relevant time consuming factor (mean 49 min ±30,92). Furthermore X-radiation exposition of the surgeon and the patient due to the application of neuronavigation appeared to be lower than the conventional technique (365,7 mGy/m2, 2 min vs. 676,56 mGy/m2 and 2,87 min in monosegmental XLIF).

Conclusion: Here, we first describe a navigated XLIF technique (nXLIF) that allows for dorsal instrumentation in single prone position without patient repositioning and demonstrated its feasibility. nXLIF may shorten the surgery duration and exposure to X-radiation compared to conventional XLIF/LLIF technique demanding for further clinical trial exploitation.