Cadaveric fibula, locking plate, and allogeneic bone matrix for anterior cervical fusions after cervical discectomy for radiculopathy or myelopathy.

OBJECT The authors have previously reported that the results of using cadaveric fibula and locking plate (CF/LP) fusion following anterior cervical discectomy (ACD) for cervical spondylotic radiculopathy and myelopathy are superior to those obtained using autologous iliac crest (AIC) grafts in the short term. The long-term results of using this construct are important in substantiating this improvement. The authors report on 246 consecutive patients (54% smokers) who underwent ACD with CF/LP fusion (175 with allogeneic bone matrix [ABM]) and compare them with 111 consecutive patients in whom AIC fusions (49% smokers) were performed by the same surgeons. METHODS The study is a retrospective nonrandomized analysis, and chi-square statistics were used. Bone densitometric studies of AIC grafts and CF grafts were performed. A paired t-test was used for statistical analysis of the results. Disease in the group of patients undergoing CF/LP fusion included soft-disc herniation with radiculopathy in 14, soft-disc hemiation with myelopathy in seven, cervical spondylotic radiculopathy in 144, cervical spondylotic myelopathy in 75, AIC graft collapse pseudarthrosis in five, and ACD with no fusion collapse/kyphosis in one. Operations consisted of single-level CF/LP fusion in 142 patients and multilevel CF/LP fusion in 104. Perioperative complications in the CF/LP group included three cases of transient hoarseness. There were no transfusions, infections, neurological injuries, or deaths. The mean hospital length of stay was 1.2 days (28% outpatient and 66% 23-hour stay). The mean follow-up period was 60 months (range 12-94 months). Ten patients were lost to follow up after 1 year. Long-term complications included one traumatic plate fracture and one symptomatic pseudarthrosis with plate fracture. At 1 year and beyond, in 245 (99.6%) of 246 patients radiographically documented fusion with no motion at the fused level on flexion-extension films was demonstrated. There was no kyphosis, no symptomatic screw plate backout, and no CF/LP graft collapse (100% in the ABM group). In the 111 consecutive patients with AIC fusions, however, there was a 17% graft-related complication rate. There were significantly fewer graft-related complications in the CF/LP group (p < 0.001). There was no difference in neurological outcome for any of the groups. In the groups undergoing single-level ACD there was a significantly greater chance of complete relief of neck pain CF/LP fusion compared with those undergoing AIC fusion (p < 0.02). There was a significantly greater chance of AIC collapse with the passage of time compared with CF graft (p < 0.02). Time until return to work was shorter for the CF/LP group by 5 to 6 weeks (p < 0.02). There was a higher rate of radiographically documented pseudarthrosis in the AIC group (p < 0.006). The mean bone densitometry for the CF/LP group was 0.7 g/cm2, significantly greater than that of the AIC group, which was 0.2 g/cm2 (paired t-test p < 0.001). CONCLUSIONS When fusion is necessary following ACD, the results of CF/LP fusion are significantly superior in the first 5 years after surgery compared with those for AIC fusions. It remains to be determined if demineralized ABM has a significant effect in enhancing fusion.