Minimally invasive sacroiliac arthrodesis: outcomes of a new technique.

STUDY DESIGN: Prospective cohort.

OBJECTIVE: Comparing efficacy and outcomes of a new technique for sacroiliac arthrodesis.

BACKGROUND: The sacroiliac joint has been described as a possible source of chronic low back pain. However, surgical treatment of sacroiliac pain and dysfunction is controversial. Arthrodesis is normally reserved as a salvage procedure when all others have failed to relieve pain and involves an extensive surgical exposure. We have developed a novel technique of sacroiliac arthrodesis using percutaneously inserted fusion cages filled with bone morphogenic protein. This study describes the radiographic and clinical outcomes of this procedure.

METHODS: Thirteen consecutive patients underwent minimally invasive sacroiliac arthrodesis between February and December 2004 at a single teaching hospital and were prospectively followed. Six patients had bilateral fusions for a total of 19 joints. The average age was 53.1 (range 45 to 62). Average body mass index was 31.2 (range 21.9 to 46.9). Mean follow-up was 29.5 months (range 24 to 35). Diagnosis was confirmed using fluoroscopically guided intra-articular injections of local anesthetic and corticosteroid when their pain was relieved 2 or more hours. Arthrodesis was only performed on patients with positive injections who subsequently had their symptoms recur. Outcome measurements included radiographic assessment for fusion and improvement in visual analog pain scale for low back pain, leg pain, and dyspareunia. Computed tomography scan to evaluate implant placement was performed postoperatively and again at 6 months to assess fusion.

RESULTS: The overall fusion rate was 89% (17/19 joints). Significant improvements were seen in final low back pain score on a visual analog scale (0 to 10) (average improvement 4.9, P< or =0.001). Leg pain improved an average of 2.4 (P=0.013). Dyspareunia improved an average of 2.6 (P=0.0028). One patient was revised to an open arthrodesis secondary to nonunion and persistent pain. There were no infections or neurovascular complications.

CONCLUSIONS: Minimally invasive sacroiliac arthrodesis via a percutaneous posterior approach is a safe and efficacious procedure, leading to a high fusion rate and significant improvement in low back, leg pain, and dyspareunia.