Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint.

Michael Woods,Denise Birkholz,Robyn Capobianco,Regina Macbarb,Adam Woods

doi:10.1155/2014/154041

Abstract

Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated. Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval. Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants. Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement.

Highlights

Invasive (MIS) sacroiliac (SI) joint fusion has gained popularity as a safe and effective treatment option for patients with recalcitrant symptoms of SI joint degeneration or disruption [1, 2]
A common method uses a series of triangular, titanium porous plasma spray (TPS) coated implants [3]
Similar to Minimally invasive (MIS) pedicle screw procedures, surgery is performed under indirect visualization using fluoroscopic guidance and the implants are placed in bone adjacent to several neural structures

Summary

Introduction

Invasive (MIS) sacroiliac (SI) joint fusion has gained popularity as a safe and effective treatment option for patients with recalcitrant symptoms of SI joint degeneration or disruption (based on joint asymmetry via radiographic imaging or contrast leakage during diagnostic joint block) [1, 2]. A common method uses a series of triangular, titanium porous plasma spray (TPS) coated implants (iFuse Implant System, SI-BONE, Inc; San Jose, CA) [3]. Similar to MIS pedicle screw procedures, surgery is performed under indirect visualization using fluoroscopic guidance and the implants are placed in bone adjacent to several neural structures. Achieving clear visualization can be difficult as the trajectory is much more anatomically complex than in lumbar spinal procedures (Figure 1). There is a potential risk for neural encroachment due to improper implant placement with possible neurologic sequelae. Given the consequences of iatrogenic nerve injury, it is advisable to employ neurologic structure localization techniques

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Discussion

Conclusion