Minimally invasive transforaminal lumbar interbody fusion for the treatment of degenerative lumbar diseases.

STUDY DESIGN: Prospective cohort study.

OBJECTIVE: To determine whether minimally invasive transforaminal lumbar interbody fusion (TLIF) using the tubular retractor system reduces the approach-related morbidity inherent in conventional open surgery.

SUMMARY OF BACKGROUND DATA: Posterior lumbar fusion using the tubular retractor system has been reported and described well. Supporters have claimed that minimally invasive techniques reduce soft-tissue trauma, blood loss, postoperative pain, transfusion needs, and the length of hospital stay, as compared with reports describing the traditional open procedure. However, there are few studies of minimally invasive TLIF, especially studies that directly compared minimally invasive and open approaches in a single center.

METHODS: Between May 2005 and December 2006, a total of 62 patients underwent 1-level TLIF by 1 surgeon in 1 hospital. Of 62 patients, 32 underwent minimally invasive TLIF using the tubular retractor system, and the other 30 underwent the traditional open procedure. The operative duration, blood loss, complications, and recovery time were recorded. The clinical outcomes were evaluated by the Oswestry Disability Index and the Visual Analog Scale. The soft-tissue injury was assessed by measuring serum creatine kinase. Radiographic images were obtained before surgery and during follow-up.

RESULTS: The minimally invasive group was found to have reduced blood loss, fewer transfusions, less postoperative back pain, lower serum creatine kinase on the third postoperative day, a shorter time to ambulation, and a briefer hospital stay. The Oswestry Disability Index and Visual Analog Scale scores were significantly lower in the minimally invasive group during follow-up. However, the open group had a shorter operative duration. The complications in the 2 groups were similar, but 2 cases of screw malposition occurred in the minimally invasive group.

CONCLUSION: Minimally invasive TLIF as a management of 1-level degenerative lumbar diseases is superior to the traditional open procedure in terms of postoperative back pain, total blood loss, need for transfusion, time to ambulation, length of hospital stay, soft-tissue injury, and functional recovery. However, this procedure takes longer operative duration and requires close attention to the risk of technical complications. Longer-term studies involving a larger sample are needed to validate the long-term efficacy of minimally TLIF.