Spinal adult degenerative deformity encompasses a wide range of pathologies including spondylolisthesis (slip of one vertebra on another), scoliosis (sideways curvature of the spine) and positive sagittal balance (unable to stand upright due to flattening of the curves in the spine). Often all three of these conditions can present in one patient. Patients present with severe back and in particular leg pain due to degeneration of the intervertebral discs leading to compression of the nerves and ‘sciatica’.
Adult scoliosis is very different from the children’s population as children have flexible curves and no nerve compression. In contrast adult curves are stiffer and harder to correct. Also due to loss of the disc height and morphology, the spine loses its natural lumbar curve, flats out and patients stoop forward.
Standard operative techniques include osteotomies of the spine where the vertebra is broken in two to correct the deformity and the spine is fused with pedicle screws and rods. This carries high complication rates including nerve damage, non-union and in rare cases, paralysis.
Newer surgical strategies address the source of the problem, realising that it is the disc and not the vertebra that is the problem. The discs can be removed and replaced with cages to restore the natural curve of the spine and indirectly decompress the nerves.
The Spinal Unit at the Royal National Orthopaedic Hospital (RNOH) is the biggest spinal department in the UK, dealing with these complex adult deformities on a regular basis. Mr Robert Lee, consultant spinal surgeon and director of the minimally invasive fellowship program at RNOH, uses minimally invasive lateral interbody cages to address these deformities rather than the traditional osteotomy techniques. Via a small incision in the flank of the abdomen, multiple cages can be inserted to correct the curvature of the spine and indirectly decompress the nerves. This technique is called anterior column reconstruction.
Over 100 patients have had this procedure, with minimal blood loss and low rates of complications. The initial 6 month to 2 year results were presented at an international conference last year. Mr Lee also uses special planning software to plan and simulate the surgery as well as computer navigation technology to insert his pedicle screws posteriorly dramatically reducing the rate of screw malposition.
"At RNOH, we are at the forefront of innovative spinal techniques. Using special software, we can analyse the patient’s deformity and plan the surgery. The use of minimal invasive anterior column reconstruction and computer navigated spinal surgery has greatly reduced patient complications with excellent early patient outcomes" says Mr Robert Lee.
The Royal National Orthopaedic Hospital is involved in a clinical study looking at the safety of the lateral access technique using a special type of retractor system