An awake, minimally-invasive, fully-endoscopic surgical technique for treating lumbar radiculopathy secondary to heterotopic foraminal bone formation after a minimally invasive transforaminal lumbar interbody fusion with BMP: technical note.

One complication associated with recombinant human bone morphogenetic protein (rhBMP-2) use in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is heterotopic bone growth at the neural foramen which results in the compression of neural structures. Here we present an awake, minimally invasive surgical approach for treating the radiculopathy that results from this excessive bone growth in the foramen. A 42-year-old male underwent a lumbar 4-sacral 1 MIS-TLIF by another surgeon. He did well in the initial postoperative period, but he began to note right leg pain and numbness in an L5 dermatomal pattern. The pain continued for 2 years despite interventional pain management, and he began to note left foot dorsiflexion weakness. An electromyography (EMG) showed a left L5 radiculopathy and a CT Lumbar spine demonstrated excessive bone growth in the right L4-5 neural foramen. The patient underwent an awake, endoscopic foraminotomy procedure utilizing a blunt tipped manual shaver drill system. The patient's radicular symptoms improved immediately, and he remained asymptomatic at the 1 year follow up. Heterotopic foraminal bone growth is one potential complication of rhBMP-2 use in the MIS-TLIF procedure. The endoscopic procedure described here is a minimally invasive surgical option that can be performed in an awake patient and is suggested a unique salvage or rescue procedure to be considered for the treatment of this potential rhBMP-2 complication.