Introduction: Neuromuscular scoliosis is a challenging pathology to treat. Surgical correction can entail long fusion constructs extending to the pelvis. This fragile patient population is poorly tolerant of the wide exposure required to place iliac screws by direct palpation and the deformity inherent to these patients makes obtaining adequate lateral intraoperative x-rays for traditional image guided placement of iliac screws difficult.
Methods: A clinical and radiographic assessment of 12 pediatric patients with neuromuscular spinal deformity (mean age 14.25 years; range 10-20 years) who underwent spinal instrumentation and fusion to the pelvis long (mean 15 levels; range 10-18 levels) at a single institution from 2007 to 2013 with an average follow-up of 31.8 months. Iliac screws were placed after identifying the posterior superior iliac spine (PSIS) and using only AP fluoroscopy (view of the inlet of the pelvis), rather than the technique of direct palpation. The accuracy of iliac screw placement was assessed with routine postoperative CT.
Results: A total of 12 patients had 24 screws placed as part of a long segment fusion to the pelvis for neuromuscular scoliosis. One patient developed pseudoarthrosis at L5-S1; however, there were no iliac screw misplacements, and no complications directly related to the technique of iliac screw placement. The average coronal Cobb angle measured 62 degrees before surgery and 44.3 degrees immediately after surgery. At last follow-up, mean coronal Cobb angle was maintained at 39.5 degrees.
Conclusions: A less invasive technique for iliac screw placement can be performed safely with a low likelihood of screw misplacement. This technique offers the biomechanical advantages of iliac fixation without the soft tissue exposure typically needed for safe screw insertion. The technique relies on identification of the PSIS and high quality AP fluoroscopic imaging for a view of the pelvic inlet.
Patient Care: By describing a new method of less invasive iliac screw placement we aim to decrease operating room time, blood loss, extent of necessary operative expose, and ultimately reduce patient complications.
Learning Objectives: By the conclusion of this session, participants should be able to 1) describe challenges associated with the operative treatment of neuromuscular scoliosis 2) describe traditional methods of iliac screw placement and why these are suboptimal for neuromuscular scoliosis patients 3) describe less invasive method of placing iliac screws using posterior iliac spine and singe AP pelvic inlet view as guidance.