360° Lumbar Fusion


using GraftonŽ DBM Putty, Grafton DBM Flex and Allograft Femoral Ring

Alexander R. Vaccaro, M.D.
Associate Professor and Co-chief of Spinal Surgery
Rothman Institute, Jefferson Hospital, Philadelphia. PA

360° Lumbar Fusion

Overview


For this procedure, a structural bone graft (femoral ring) was placed anteriorly, supplemented with Grafton DBM Putty and autologous iliac crest bone graft. Posteriorly, iliac crest bone graft was used with Grafton DBM Flex as an osteoinductive element, combined with internal fixation to maintain appropriate sagittal alignment.

Patient Background


The patient is a 50-year-old female who previously underwent an anterior/posterior lumbar decompression and fusion procedure for spinal stenosis and instability. She presented recently with severe leg pain and neurogenic claudication due to junctional degeneration and instability. The goal is to relieve that pressure surgically and stabilize the spine in order to allow her to walk better.

Procedure


  • The patient is initially approached anteriorly. Once the discs are exposed, the annulus fibrosus is incised and the Sharpey's fibers are separated from the vertebral endplates with a cob.
  • The disc material and articular cartilage is meticulously removed to ensure that the graft has excellent contact with the end plates of the adjacent vertebrae. Curettes are moved in a circular manner to avoid a mismovement that can injure the great vessels, which are gently retracted during the procedure.
  • Small punctuate holes are created within the subchondral cartilage of the respective endplates to allow blood to flow to the graft substance.
  • An allograft structural source from the femur of a cadaver is used to fill the disc space. The femur has been shaped to fit precisely into the disc interspace.
  • To accelerate the fusion process, the center portion of the femoral ring allograft is filled with a mixture consisting of the patient's iliac crest and Grafton DBM Putty.
  • The graft should be a bit wider anteriorly and narrower posteriorly so that it will afford some lordosis. The graft is well recessed approximately 2 to 3mm below the vertebral endplates.
  • Repeat procedure for allograft ring placement.
  • The patient is then approached posteriorly and the posterior elements of the spine are properly exposed. A decompression is performed, followed by spinal reconstruction with an appropriate internal fixation device according to manufacturer's recommendation.
  • The posterior elements are then irrigated and properly decorticated for graft placement.
  • Two pieces of Grafton DBM Flex, previously rehydrated in saline solution, are cut in half, lengthwise, into four narrow strips, which are then placed over the posterior elements of the decorticated transverse processes.
  • Once the Flex strips are in place, bone and Grafton DBM Putty mixture is laid over the strips and packed into place.
  • The transverse connectors of the implant system are then attached.