gms | German Medical Science

Objective: Symptomatic spondylytic lesions of the lumbar spine require a combination of intervertebral and transpedicular fusion. However due the frequent distortion of the pedicle anatomy severe angulation is often necessary, requiring a wide exposure of the paraspinal muscles. We describe our technique with robotic-assisted percutaneous placement of the instrumentation followed by a microscopic approach to the foramen in order to decompress nerval structures and provide placement of a TLIF cage.

Method: We describe ten patients treated by a robotic-assisted percutaneous instrumentation followed by microscopic TLIF-cage placement. All patients harboured a symptomatic true isthmic spondylolysis either L4/5 or L5/S1 at least Meyerding grade 2. All procedures were performed with SpineAssist (MazorRobotics) and a percutaneous instrumentation system where reduction procedures can be performed.

Results: 40 pedical screws were placed in ten patients, the mean intraoperative time for complete k-wire placement was 17.1 minutes with a mean radiation time (dose) for k-wire placement 9.9 seconds (6.2 mGy), to screw placement 16.3 seconds (10,5 mGy). With a mean skin incision of 4.5 cm blood loss was 142,2 ml on average. Patients were mobilized on the 2^nd postoperative day, with no morbidity detected within the follow-up period of at least 6 months. Accuracy according to Gertzbein criteria was 95 % A and 5% B. One patient required revision surgery due to a hematoma at the cage insertion place.

Conclusions: The combination of robotic-assisted percutaneous spinal instrumentations and microsurgical implantation of the TLIF-cage provide a significant benefit for the patient due to immediate mobilisation and almost no intra-op radiation exposure. With minimal exposure of paraspinal muscles in this young patient group the procedure is comparable to lumbar disc surgery.