Anterior cervical discectomy with freeze-dried fibula allograft. Overview of 317 cases and literature review.
METHODS
A retrospective review of 317 patients to determine the efficacy of allogeneic fibula arthrodesis after anterior cervical discectomy.


OBJECTIVE
To examine the efficacy of allogeneic fibula as an alternative fusion substrate after anterior cervical discectomy, and to determine the effects of cigarette smoking on the healing of fibula allografts.


BACKGROUND
The use of autogeneic iliac crest is associated with graft harvest complications in up to 20% of patients. Most studies reporting on the use of allogeneic iliac crest cite a high collapse rate. Few studies exist that note the efficacy of allogeneic fibula in this procedure and the effects of cigarette smoking on fusion rate.


METHODS
From 1988 to 1993, 317 patients underwent grafting by the Smith-Robinson technique with allogeneic fibula after anterior cervical discectomy. Patients who described themselves as habitual cigarette smokers or who smoked during the perioperative or postoperative period were categorized as smokers. All patients were immobilized in a rigid cervical orthosis (Philadelphia collar) for at least 10 weeks postoperatively.


RESULTS
A minimum of 2 years follow-up was achieved in 289 patients. In all, 162 men and 127 women had a total of 311 levels grafted, and the mean follow-up period was 33 months (range, 24 to 51 months). Of patients who received allogeneic fibula at one level, 90% (242/269) achieved radiologic fusion. The fusion rate was 92% (182/198) among nonsmokers compared with 85% (60/71) among smokers (not a statistically significant difference; P = 0.120). After two-level procedures, 72% (13/18) of the patients showed fusion. The fusion rate was 50% (2/4) among smokers compared with 79% (11/14) among nonsmokers (P = 0.53). When one-level arthrodesis (90%) was compared with two-level arthrodesis (72%), the difference approached statistical significance (P = 0.054). Neither of the two patients, both nonsmokers, who received grafts at three levels achieved fusion. There were no infections, and no grafts collapsed. Two grafts extruded (0.6%), but these were partial and did not require reoperation. Both patients fused and constituted the only patients with more than 10 degrees of angulation in the series. Graft subsidence occurred in 5% (17/311) of the grafts, mostly in the beginning of the series, and was not problematic. This phenomenon was thought to have been caused by overaggressive removal of the cortical endplate.


CONCLUSIONS
Allogeneic fibula is an effective substrate for use in achieving fusion after anterior cervical discectomy. Maximal results are achieved with its use at one level in nonsmokers. Cigarette smoking decreased the fusion rate with allogeneic fibula in the anterior cervical spine, but not by a statistically significant amount.
D002574:Cervical Vertebrae / Q000473:pathology / Q000601:surgery*; D017586:Diskectomy; D005260:Female; D005360:Fibula / Q000637:transplantation*; D005500:Follow-Up Studies; D005612:Freeze Drying; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects; D013122:Spinal Diseases / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D014184:Transplantation, Homologous; D014945:Wound Healing