ABSTRACT
BACKGROUND: Since the 1980s, numerous operations have replaced posterior lumbar interbody fusion (PLIF) with human bone. These operations often involve expensive implants and complex procedures. Escalating expenditures in lumbar fusion surgery warrant re-evaluation of classical PLIF with allogeneic ilium and without instrumentation. The purpose of this study was to determine the long-term fusion rate and clinical outcomes of PLIF with allogeneic bone (allo-PLIF). METHODS: Between 1981 and 2006, 321 patients aged 12-80 years underwent 339 1-level or 2-level allo-PLIFs for degenerative instability and were followed for 1-28 years. Fusion status was determined by radiographs and as available, by computed tomography scans. Clinical outcome was assessed by the Economic/Functional Outcome Scale. RESULTS: Of the 321 patients, 308 were followed postoperatively (average 6.7 years) and 297 (96%) fused. Fusion rates were lower for patients with substance abuse (89%, P = 0.007). Clinical outcomes in 87% of patients were excellent (52%) or good (35%). Economic/Functional Outcome Scale scores after initial allo-PLIF on average increased 5.2 points. Successful fusion correlated with nearly a 2-point gain in outcome score (P = 0.001). A positive association between a patient characteristic and outcome was observed only with age 65 years and greater, whereas negative associations in clinical outcomes were observed with mental illness, substance abuse, heavy stress to the low back, or industrial injuries. The total complication rate was 7%. CONCLUSIONS: With 3 decades of follow-up, we found that successful clinical outcomes are highly correlated with solid fusion using only allogeneic iliac bone.
