The purpose of this retrospective study, is to demonstrate the survivorship and clinical effectiveness of the Wallis implant, against low back pain and functional disability in patients with degenerative lumbar spine disease. The Wallis Interspinous implant, was developed as a minimally invasive and anatomically conserving procedure, without recourse to rigid fusion procedures. The initial finite element analysis and cadaver biomechanical studies showed that the Wallis ligament improves stability in the degenerate lumbar motion segment. Unloading the disc and facet joints reduces intradiscal pressures at same and adjacent levels allowing for the potential of the disc to repair itself. A total of 157 patients who had wallis ligament insertion between 2003 and 2009 were reviewed, with a mean age of 54 and were followed for 48 months on average. Patients were assessed pre-operatively and post-operatively every 6 months by VAS pain score, Oswestry Disability Index and SF-36. 90% of patients improved, to show a minimal clinical difference, compared to the pre-operative evaluation. There is overall 75-80% good clinical outcome. Low infection rate of 1.1%. Two cases of prolapsed discs at the same level requiring further discectomy, 7 required fusion. No fractures or expulsions. The Wallis implant represents a safe non-fusion stabilisation device in the treatment of degenerative lumbar spine disease with canal stenosis. There is less soft tissue damage, quick rehabilitation, less morbidity and associated low complication rate

Objectives

We performed a systematic review of the literature to determine the safety and efficacy of bone morphogenetic protein (BMP) compared with bone graft when used specifically for revision spinal fusion surgery secondary to pseudarthrosis.