RESUMO
INTRODUCTION: The efficacy and economy of an alternative sparing method for posterior lumbar interbody fusion (PLIF) using a single cage fixed with pedicle screws placed on a single side (SS group, n=22) was compared to that of a standard bilateral protocol using two cages and pedicle screws placed bilaterally (BL group, n=15). METHODS: All PLIFs were non-compensation cases done at a single level by a single surgeon and were similar in most background characteristics. Significant differences were not found between the two groups in fusion rates, complications or in 2-year prospectively collected outcomes including percent improvement in back and leg pain (visual analog scales) and the Oswestry disability index. RESULTS: Perioperative results significantly favored the SS group: BL patients lost 81% more blood, used 74% more time for surgery, stayed in hospital 1.7 days longer, and the hospital-related cost per procedure was twice as high. Currently, the SS procedure typically averages less than 1 h and blood loss less than 50 mL. In summary, the BL and SS groups had similar outcomes while the SS procedure provided substantially superior efficiency and economy. CONCLUSION: In conclusion, the results of this retrospective comparative level III study warrant further studies on the SS protocol which may lead to the adoption of this minimally invasive protocol in the standard practice of PLIF in selected cases.