Anterior and posterior allografts in symptomatic thoracolumbar deformity

The radiographic and clinical results of 105 patients with symptomatic spin al deformities were categorized retrospectively based on surgical approach and type of bone autograft or allograft used for each patient's fusion surg ery into seven different groups and compared with one another. The three bo ne autograft control groups were posterior autograft only (n = 20), anterio r autograft only (n = 6), and combined anterior and posterior autograft (n = 12). The allograft groups were posterior morcellized allograft (n = 7), p osterior morcellized allograft and anterior autograft (n = 11), anterior st ructural interbody allografts and posterior mixture of allograft and autogr aft (n = 37), and anterior strut allograft with posterior mixture of allogr aft and autograft (n = 12). Radiographs revealed high pseudoarthrosis rates for adults with a posterior-only allograft and with anterior strut allogra fts spanning four or more levels. Results of the self-assessment outcomes q uestionnaire, at a mean follow-up period of 52 months, revealed less pain a nd improved cosmesis for all groups, and improved function in patients who had undergone combined anteroposterior fusion. The authors conclude that po sterior cancellous allograft is a poor substitute for autograft bone and th at strut allografts spanning more than four levels require technique modifi cations to enhance their effectiveness. in general, anterior structural all ografts are effective in maintaining correction, result in fusion rates com parable to those of autografts, and correlate to improved outcomes.