To assess radiological fusion rates in posterolateral fusions using SiS-CaP.

Retrospective, radiological follow-up study.

Single surgeon series of 76 consecutive patients were evaluated, in a regional spinal unit. All patients had clinical and radiological (MRI) spinal canal stenosis secondary to degenerative spondylosis or spondylolisthesis. Surgery consisted of instrumentation, decompression and meticulous preparation of the posterolateral graft bed by removal of all soft tissues posterior to the inter-transverse membrane and decortication of transverse processes (TPs). SiS-CaP putty was injected into this gutter and moulded around the instrumentation. Good quality, well prepared bone chips from the posterior decompression were seeded into the putty. Patient radiographs were reviewed at 3-6 months, 1 year and 2 years.

Radiographs were assessed using a protocol to examine granularity, bone formation and evidence of pseudarthrosis, based upon previously reported literature ¹ and our personal experience.

Of the 76 patients, 26 were excluded. M:F was 21:29. Mean age was 58yrs. Average number of motion segments fused per case was 2.2. There was one pseudarthrosis with metalwork fracture, and thus a total fusion rate of 98%. In addition, one patient had scanty bridging of TPs, and one patient had lucency around the S1 screws.

SiS-CaP, as a bone graft substitute in posterolateral instrumented fusions, gives comparable results to published fusion rates using autologous iliac crest grafting and/or Bone Morphogenic Protein ². Moreover, it avoids the associated morbidity of iliac bone harvest.

There is believed to be a correlation between congenital idiopathic scoliosis and congenital heart disease (CHD). Clinical and cardiological data was recorded for 3538 adolescents suffering from CHD. Data collected included the type of scoliosis; the direction of the curve; the Cobb angle; the number of curves and the presence or not of previous corrective cardiac surgery. Over 30% of the study group were found to suffer from scoliosis and a positive correlation with specific syndromes was also identified. The mean age of the patients was 34.0 +/− 14.0 years. The maximum Cobb angle was 107 degrees while the median was 7.6 degreees. Scoliosis was present in 37/188 (19.7%) was Eisenmenger syndrome (with R-L shunt) and 60/158= 38% with complex cardiac anatomy. There were also 20/103= 19.4% patients with univentricular (Fontan) circulation. Scoliosis was not necessarily related to previous corrective cardiac surgery, contrary to the current assumption in the literature. The hypothesis of common genetic pathway defects expressed both in cardiovascular and musculoskeletal organogenesis was raised and the TGF-beta pathway involvement is speculated.