Repairing sacral plexus avulsion with the S1 nerve at the uninjured side as its power source: case report and literature review

Abstract

Objective To elevate safety and efficacy of repairing sacral plexus avulsion with transfer of the S1 nerve at the uninjured side as its power source nerve.Methods In November 2007,a 10-year-old boy was admitted into our institute who had undergone surgery in a local hospital for a complex pelvic fracture with dissociation of the sacroiliac joint.Preoperative check-ups showed anesthesia in the glutei,hamstrings,and calf muscles of the left lower limb.X-ray revealed a previous operation on the sacroiliac joint,fractures of the superior and inferior rami of the left pubis,and dislocation of the pubic symphysis.A lumbar myelogram showed multiple pseudomeningoceles involving the right L4 to S1 nerve roots,indicating sacral nerve root avulsion.Electromyography presented a neurogenic injury.Neuropotentials of the left tibial nerve and peroneal nerve disappeared.A surgical reconstruction of the sacral nerve was performed 3 months after the injury,with a nerve graft of approximately 15 cm in length from the common peroneal nerve.One end of the nerve graft was anastomosed to the proximal stump of the right SI nerve root.The distal end of the nerve graft was divided into 2 fascicles,one sutured to the left superior gluteal nerve and the other to the branch of the sciatic nerve innervating hamstrings.Results The operation lasted 5 hours,with perioperative blood loss of 2000 mL and blood transfusion of 1600 mL.The wound healed primarily.The fight lower limb had nearly normal motions 4 days after operation.The patient had numbness in the lateral plantar region of the healthy limb(4 cm × 12 cm in area)4 days after surgery,improved(2 cm × 6 cm in area)20 days after surgery,and the symptom disappeared within 18 months.The strength of the glutei and hamstrings muscles at the left limb improved to the level of M3 18 months after surgery.The patient had M4 weakness in the peroneus longus which recovered within one year.Conclusion The S1 root of the plexus from the healthy side can be considered as a donor nerve for transfer in patients with root avulsion of the lumbar or sacral nerve plexus. Key words: Lumbosacral plexus; Pelvis; Fractures; Wounds and injuries