Comparison of Galveston Rod vs. Iliac Screw Pelvic Fixation Techniques in Neuromuscular Spinal Deformity Correction

Information provided by

Lawrence G. Lenke, MD

The Jerome J. Gilden Professor of Orthopedic Surgery

Co-Chief Pediatric & Adult Spinal, Scoliosis & Reconstructive Surgery

Keith Bridwell, MD

Orthopaedic Surgeon

Washington University School of Medicine

• a - Medtronic Sofamor Danek

Introduction: Traditional means of gaining sacropelvic fixation in neuromuscular spinal deformity patients has been with the use of Galveston rods placed into the iliac wing. However, issues with radiographic halos around the rods (loosening), difficult rod contouring, and inability to line up to screw anchors in the lumbar spine has led to the use of iliac screws in this patient population.

Purpose: To evaluate the safety and efficacy of iliac screws as a method of pelvic fixation in neuromuscular spinal deformity correction using the Galveston technique as a control group.

Methods: A matched cohort analysis of 40 patients undergoing posterior spinal fusion for neuromuscular spinal deformity requiring fusion to the pelvis (T2-pelvis) and having a 2-year radiographic and clinical follow-up was performed. 20 Galveston technique (GT) patients were compared to 20 iliac screw (IS) patients. All GT patients had sublaminar wires for their lumbar anchors, while the majority of IS patients had at least 2 if not more lumbar and sacral pedicle screws placed in addition to the iliac screws. GT patients were treated between 1994 and 2000, while the IS patients were treated between 1994 and 2001. Standard 5.5mm rods were used for the GT, and standard 5.5mm rods and 7.0 diameter by 70mm long iliac screws were used for the IS patients. All patients had morselized allograft bone in addition to any autogenous local bone used for the arthrodesis.

Results: Table 1 shows the pre, postoperative, and latest follow-up measurements for pelvic obliquity, coronal Cobb measures, coronal and sagittal C7 plumbline, and T1 offset. There were no significant differences between the two groups in any of these measures except for latest follow-up pelvic obliquity, which showed a definite trend to be less in the IS patients (last f/u 4.3º) versus the GT patients (last f/u 7º), that was just beyond statistical significance (p=.06). 12 GT patients versus 5 IS patients had greater than 2mm of halo signs around the pelvic anchor devices at latest follow-up (p<.05). The GT group had 4 broken rods and 2 reoperations while the IS group had 1 broken screw and no re-operations. There were no complications referable to insertion of either the Galveston rod or iliac screws.

Conclusions: Using iliac screws for pelvic fixation in neuromuscular spinal deformity requiring fusion to the pelvis affords a strong trend for superior maintenance of pelvic obliquity correction with fewer implant failures than use of the Galveston technique. The IS technique avoids complex lumbosacral three-dimensional rod bends, and provides the ability to use pedicle screw anchorage throughout the entire lumbar spine if so desired.

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