Comparison between allograft plus demineralized bone matrix versus autograft in anterior cervical fusion: A prospective multicenter study

Study Design. This study analysed the fusion results aFan sllngraftdemineralized bone matrix composite versus autograft in a prospective series of patients undergoing surgery for cervical disc disease.Objectives. To determine the fusion rales; oF allograftdorm I nera I ized bone matrix composite In anterior cervical fusion as compared with the gold standard autograft.Summary of Background Data, For the anterior cervical fusion, the usa of freeze-dried allograft is well documented in the literature, citing its effectiveness and inferior fusion rates. The use of demineralizcd bone matrix In conjunction with freeuadrled allograft in anterior cervical Fusion has nut been reported.Methods. This study was done in a prospective fashion in two medical centers. One group received autograft from the anterior iliac crest, whereas others received frcczedriect allograft augmented with deminerelized bona matrix (Grafton, Osteotech, Inc., Shrewsbury, New Jersey. For the autograft group, the standard Smith-Robinson grafting technique was used. For the allograft composite group., demlncralized bone matrix was pasted onto tha freezedried allograft and into the disc space before graft insertion, Tho autograft group consisted or 38 patients with age ranging 26-71 years (mean, 46.1 years) and follow-up periods of 12-33 months (mean, 16,4 months). There were 19 oneavel 17 two-level, and two three-level fusions. Similarly, the allograft group consisted of 39 patients with age ranging 28-80 years [mean, 48.0 years) with follow-up period of 12-31 months (mean, 17,5 monthsh There were 19 ore level, 16 two-level, and four three-level fusions. Clinical and radiographic follow-up evaluations were completed at 3-month intervals, Radiographs taken 12 months after suryury were analyzed blindly.Results. Pseudarthrosis developed in 46.2 of patients (33,3% of levels) in lhe allogratdemineralizcd bone matrix group compared with 2&.3% (22% of levels) in the autograft group (P - 0.11) for patients, P - 0.23 for levels). For patients undergoing Iwolevel fusions, 37,5% of allogreftdemlneralized bone matrix failed compared with 23,D% Df autografts. For singlelevel fusions, 47,4% of allograft patients developed a paeudarthrDsis compared with 26,3% in the autograft gtoup. Graft collapse of a 3 mm was noted in 11% of the autograft group versus 19% in the allograft demineralized bone matrix group (P = 0.32). Graft collapse Of s 2 mn occurred in 24,4% of autograft patients compared with 39.7% of the allograft-demineralizetl bone matrix group (P - 0,09). Smokers had an increased rate of pseudarthrosis (47.1%) compared with nonsmokers (27.9%. P = 0.13),Conclusions. The study revealed that the allograt demineralizod bone matrix construct gives a higher rate of graft collapse and pseudarthrasls when compared with autograft in a prospective series, ai tha ugh the differences wera not statistically significant, The pseudarthrosis rate in the serias may be high because of tho large percentage of smokers and radiographic evaluation techniques. For the purpose of solid radiographic fusion, tho use of autograft is recommended In anterior cervical surgery until other acceptable osteoinductive materials are developud.