Are 2 cages needed with instrumented PLIF? A comparison of 1 versus 2 interbody cages in a military population.

Bovine biomechanical data have demonstrated adequate stability of a single threaded interbody cage when combined with a unilateral facet screw during posterior lumbar disc excision and interbody fusion (PLIF). Instrumented PLIF surgery using 1 versus 2 interbody cages was studied in 35 military men with disc disease and chronic low back pain. All patients underwent instrumented PLIF with bilateral diskectomy and partial facetectomy, pedicle screws, autogenous iliac crest bone graft, 1 or 2 interbody cages, and posterior lateral fusion. After an average of 15 months' follow-up, the 2-cage group had a higher rate of dural tear, but rates of other complications, hospital stay, fusion rates, pain levels, functional outcomes, and patient satisfaction were good and did not differ between groups. Costs were higher for the 2-cage group by 1728 dollars per patient.