Endoscopic decompression of L3 nerve root in a case of adult spinal deformity correction with post-operative neurological deficit: a case report

Adult spinal deformities (ASD) have a very high incidence of postoperative neurological decline. Spine surgeons all over the world are broadening the indications of endoscopic spine surgery (ESS) with similar/better outcomes to other conventional spine surgeries. In this report we present a case of L3-radiculopathy post ASD correction and its management with ESS. A 78-year-old female operated for ASD presented with backache, and right-side-dominant radiating leg pain. Imaging showed distal junctional failure with left rod fracture between L5-S1 and screw loosening with gross sagittal imbalance. She was treated with L4 pedicle subtraction osteotomy (PSO) with T10-iliac posterior fixation with use of satellite rods at PSO site. Post-operatively she developed left-sided L3 motor deficit. Imaging revealed left L3 root compression by bone fragment near the left L3 pedicle screw-head. We presume that, since the L3 pedicular screw had to be inserted deeper than the other screws to accommodate the satellite-rod, the bone in the area near the screw head (part of either the pedicle or facet) caused compression of the left L3 nerve root. The patient was treated with interlaminar ESS under awake anaesthesia and the compressing bone was drilled out. Post-operatively, patient had rapid relief of the radicular pain and improvement in the left quadriceps (L3) power with no recurrence at 1-year follow-up. Thus, post-operative iatrogenic neurological deficits can be treated successfully using ESS when the exact cause of the deficit is identified and is amenable to endoscopic removal. We could successfully treat a case of left-sided L3-radiculopathy, caused due to protruding bony spur after ASD correction surgery with ESS.