Custom solutions for transforaminal lumbar interbody fusion surgery.

Abstract

Pre-surgical planning using 3D printed anatomical models enables the preparation of a "patient-specific" kit for instumented spinal fusion surgery. This approach has the potential to decrease operating time, while also offering logistical benefits and thus cost savings for the hospital. We report our experience with this method in 73 consecutive patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) over a 12-month period at a single centre and performed by a single surgeon. Using patient imaging and custom surgical planning software, a patient-specific MIS TLIF kit was manufactured for each case to include a custom pedicle screw guide, and 3D printed self-guided dilators and tubular retractors. The required pedicle screws, rods, and cages were separately supplied and packaged together with the patient specific kits. Additional implants were available on shelf in case of a size discrepancy between the kit implant and intraoperative measurements. Each patient's spinal model was also included for use in both surgical planning and patient education. Efficiency metrics were recorded as average theatre time (164 min), the number of sterile trays required per case (14), mean X-ray dose (1359 cGycm2), number of operative waste bags (0.8 contaminated, one uncontaminated bags), and the average length of hospital stay (5.4 days). The kit implants were deemed appropriate for 394/403 pedicle screws over 129 levels, 137/146 rods, and 19/90 cages. Pedicle screw placement was independently verified as accurate by postoperative CT in 403/403 cases. Across all 73 patient admissions, there was one intraoperative complication (dual tear), no autologous blood transfusions or blood products were administered, and no revision surgery. Our experience supports a viable application of patient-specific customs solutions in spine surgery.