FREEZE-DRIED ALLOGRAFT FOR POSTERIOR SPINAL-FUSION IN PATIENTS WITH NEUROMUSCULAR SPINAL DEFORMITIES

Study Design. The effectiveness and safety of freeze-dried allograft f or posterior spinal fusion in patients with neuromuscular disorders we re evaluated retrospectively. Summary of Background Data. Because the harvest of an adequate quantity of autogenous bone graft from patients with neuromuscular deformity who have instrumentation and fusion to t he pelvis is difficult at best, an alternative graft source usually is needed, Allograft bone, most commonly processed fresh-frozen or freez e-dried, has been used frequently for posterior spinal fusion in patie nts with neuromuscular deformity. However, a relatively high risk of i nfection and pseudarthrosis has been reported for this procedure. Meth ods. Forty patients with neuromuscular deformity with an average age a t the time of surgery of 14 years and 2 months (range, 5 years, 4 mont hs to 23 years, 8 months) met the inclusion criteria. All of these pat ients underwent more than 2 years of follow-up evaluation. They were e valuated for rates of infection, pseudarthrosis, and transmissible dis ease. Results. Thirty-eight patients had solid fusion at the most rece nt follow-up visit. Definite pseudarthrosis was detected in one patien t (2.5% of the study group), which was treated successfully. Another p atient's (2.5%) spinal curve progression of more than 10 degrees and r od breakage led the authors to diagnose a probable pseudarthrosis. She had a stable spine that did not require revision at 68 months after s urgery. For the 32 patients who underwent posterior surgery only, the pseudarthrosis rate was 3.1%. There were no acute deep wound infection s. Superficial infection occurred in two patients (5%) and delayed dee p sterile drainage in one patient (2.5%). All cases of infection resol ved with appropriate management. Delayed deep wound infection develope d in one patient (2.5%) as a result of staphylococcus coagulase negati ve at 34 months after surgery. Successful treatment has consisted of i mplant removal, debridement, and appropriate antibiotics. Transmissibl e disease attributable to allograft has not been detected to date. Con clusion. Freeze-dried allograft fusion is a reliable and effective met hod for posterior spinal fusion in the patients with neuromuscular def ormity.