The goal of this prospective study was to review a series of 27 patients who underwent bilateral posterior lumbar interbody fusion with instrumented pedicle fixation and two HYDROSORB (known generically as 70:30 poly[L-lactide-co-D,L-lactide]) rectangular cages packed with locally harvested autograft at a total of 48 levels, and to assess the safety and efficacy of this novel technique. This analysis, conducted at a mean of 26 months of follow up, is the first report of a long-term evaluation of this technique. Fusion rates and clinical outcomes are presented.
A prospective clinical and radiographic review of findings in 27 consecutive patients was performed. Fusion rates and clinical outcome were assessed at 6-month intervals up to the 32-month follow-up end point. Two patients with four corresponding fusion levels were lost to follow up.
Radiographic evidence of satisfactory fusion was achieved in 42 (95.5%) of 44 levels fused. Satisfactory fusion at all levels was achieved in 23 (92%) of 25 patients. Two patients required repeated operations for treatment of symptomatic pseudarthrosis during the study period. The likelihood of all levels attaining fusion in a given patient decreased as the number of levels treated increased, which is consistent with previously published studies. Nonetheless, fusion rates per treated level were similar for patients in whom one to three levels were treated. No significant surgical complication occurred.
Posterior lumbar interbody fusion in which the HYDROSORB bioabsorbable implant packed with locally harvested autograft and segmental internal fixation are used appears to be an interbody fusion alternative whose efficacy is comparable with previously reported procedures.