Study design: Prospective cohort study.
Objectives: To determine the statistical difference between the minimally invasive and traditional open approach for one-level instrumented posterior lumbar interbody fusion by comparing the perioperative data, clinical outcome, and radiographic result.
Summary of background data: Posterior lumbar fusion performed with mini-incision using tubular retractor has been advocated as a minimally invasive technique. Proponents have claimed that minimally invasive techniques reduce postoperative pain, blood loss, transfusion needs, and the length of hospital stay compared with the traditional open techniques. But there was no well-designed comparison study that supports these claims.
Methods: We studied a consecutive series of 61 patients who underwent one-level PLIF procedure (32 cases performed with minimally invasive approach and 29 cases with traditional open approach) by one surgeon at one hospital, from October 2003 until October 2004. The following data were compared between the 2 groups with 1-year minimum follow-up: the clinical and radiographic results, surgical time, estimated blood loss, transfusion needs, postoperative back pain by visual analogue scale, time needed before ambulation, length of hospital stay, and complications.
Results: There was no significant difference between the 2 groups in the aspects of the clinical and radiographic results with 1-year minimum follow-up. The minimally invasive group was found to have a significantly less blood loss, less needs of transfusion, less postoperative back pain, shorter recovery time before ambulation, and shorter length of hospital stay. However, the minimally invasive group needed significantly longer surgical time and showed 2 cases of technical complications.
Conclusions: The present study, which was based on the authors' initial experience with the minimally invasive approach, could confirm favorable results reported by previous uncontrolled cohort studies in the aspects of less blood loss, less transfusion need, less postoperative back pain, quicker recovery, and shorter hospital stay. It also showed the similar surgical efficacy of the minimally invasive approach with that of the traditional open technique. However, the minimally invasive technique needs longer surgical time and a prudent attention to lower the risk of technical complications. Further long-term, prospective studies involving a larger study group are needed to determine the benefits of this minimally invasive percutaneous procedure.