The Early Clinical and Radiographic Outcomes of Robotic-Assisted Midline Lumbar Interbody Fusion (MIDLIF) With Expandable Interbody Spacers: A Case Series.

OBJECTIVE

To assess the early clinical and radiological outcomes of the midline lumbar interbody fusion (MIDLIF) approach with the use of robotic assistance and expandable spacers.

METHODS

A retrospective case series was performed on patients who underwent MIDLIF procedures for the treatment of degenerative spinal diseases, with a minimum of three months postoperative follow-up. Demographic (age, gender, body mass index [BMI], comorbidities, and diagnoses), surgical data (operative time, blood loss, hospital stay, intraoperative complications), patient-reported outcomes (PROs) (visual analogue scale [VAS] back pain and disability (Oswestry disability index [ODI]), and radiographic data were collected.

RESULTS

In total, 42 patients were included, with an average age of 53.6 years and a BMI of 28 kg/m². Surgical data showed the mean total operative time was 98.8 minutes, and the mean blood loss was 17.1 mL with no intraoperative complications. At three-month follow-up, all mean PROs showed statistically significant improvement (p<0.05) when compared with baseline. VAS back pain improved from 7.5 (standard deviation (stdev) 7.5±0.7) preoperatively to 3.0 (stdev 1.0) at three months postoperative, while ODI improved from 58.7 (stdev 7.2) to 26.3 (stdev 10.3) at the same time points. Radiographic data showed that using robotic assistance for planning and placing cortical screws yielded high accuracy, as evidenced by a mean tip deviation of 1.2 mm (stdev 0.6 mm), mean tail deviation of 1.1 mm (stdev 0.4 mm) and a mean angular offset of 1.4 mm (stdev 0.7). Two (4.8%) patients had postoperative complications at three-month follow-up, including a wound infection and one report of wound dehiscence.

CONCLUSION

MIDLIF is an efficient, reproducible surgical procedure with a low complication rate that resulted in significant improvements in early PROs. Robotic assistance for planning and placing cortical screws in MIDLIF was highly accurate. These initial findings suggest that using robotic assistance adds value to MIDLIF procedures and is a viable alternative to traditional posterior fusion procedures.