ANTERIOR FRESH-FROZEN STRUCTURAL ALLOGRAFTS IN THE THORACIC AND LUMBAR SPINE - DO THEY WORK IF COMBINED WITH POSTERIOR FUSION AND INSTRUMENTATION IN ADULT PATIENTS WITH KYPHOSIS OR ANTERIOR COLUMN DEFECTS

Study Design. This was a prospective study of 24 adult patients with k yphosis or anterior column spinal defects treated with anterior fresh frozen allograft for anterior column defects and posterior instrumenta tion and autogenous grafting. Objectives. The objectives of the study were to assess the effectiveness of the anterior allograft in maintain ing sagittal correction and to assess anterior incorporation. Summary of Background Date. Twenty-four patients were followed for a minimum o f 2 years (range, 2 + 0-5 + 4 years). Methods. Upright radiographs wer e analyzed before surgery, immediately after surgery, and at the final follow-up examination to assess success of anterior fusion and mainte nance of correction. A strict four-point grading system was used. Two independent observers analyzed the radiographic results. Results. Only two patients showed some collapse of their anterior allograft. The ot her 22 patients maintained correction, attaining a Grade I or Grade II fusion. Semiconstrained instrumentation was used posteriorly in the t wo patients who had graft collapse. Conclusions. Anterior structural a llograft worked effectively to maintain correction of kyphosis if comb ined with posterior instrumentation and autogenous grafting. Rigid for ms of posterior instrumentation were preferred.