Use of anteroposterior view fluoroscopy for targeting percutaneous pedicle screws in cases of spinal deformity with axial rotation

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Over the past decade percutaneous pedicle screws have become popular for the minimally invasive treatment of spinal disorders. However, until the last 5 years the presence of a significant spinal deformity was regarded as a relative contraindication for percutaneous instrumentation. Recent advances in surgical technique and intraoperative technology have made percutaneous fixation in complex spinal pathologies more commonplace. The authors report their experience using a parsimonious method for uniplanar fluoroscopic targeting of pedicles in challenging cases.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors performed a retrospective analysis of patients with adult spinal deformity who underwent percutaneous pedicle screw instrumentation from 2008 to 2013. Cases were included if a spiral slice postoperative CT scan was obtained. All cases had a minimum of 10° of axial rotation and typically had additional accompanying anatomical abnormalities. Screws were assessed for any pedicle violations as well as any impingement of the surrounding facet joints.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>A total of 410 pedicle screws were placed in 36 patients with an average 6.4 levels of instrumentation per patient. The mean age was 67 years (range 44–86 years) and there were 25 females. Of the 410 screws, 29 (7.1%) had some medial or lateral pedicle violation. Of these, 15 (3.7%) were Grade 1, 6 (1.4%) were Grade 2, and 8 (2.0%) were Grade 3 violations. Of the Grade 3 violations, 2 each were at the L-4, L-5, and S-1 levels, and 1 each was at the T-10 and L-1 levels. Two of the patients had symptoms and both underwent screw repositioning, one during the same admission and the other in a delayed fashion. Both were at the L-5 and S-1 levels with anatomically highly medialized pedicles. There were no motor deficits, and both removals were for numbness. Of the 72 screws at the proximal end of the construct, there were 6 facet violations (8.3%). Four (5.6%) of these were Grade 1, 1 (1.4%) was Grade 2, and 1 (1.4%) was Grade 3.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The anteroposterior fluoroscopic technique can be effectively used by spinal surgeons to cannulate the pedicles in patients with rotational deformities. The complication rate in this challenging population is acceptable and is in accordance with the existing literature. However, caution should be used at L-5 and S-1 when the pedicle is narrow and highly medialized, rendering an indistinct medial wall on anteroposterior imaging.</jats:p></jats:sec>

Percutaneous versus open pedicle screw fixation for treatment of thoracolumbar fractures: Systematic review and meta-analysis of comparative studies

“…Careful patient selection is required for this minimally invasive operation, given that percutaneous pedicle screw fixation is heavily dependent on imaging for level confirmation, for example fluoroscopic guidance [22]. Patients with rotational deformities, or even obesity and osteopenia, may have anatomy which could obscure imaging guidance, and thus may not be suitable for percutaneous pedicle screw fixation [1]. Studies have also suggested other contradictions including multi-level vertebral fractures, pedicle fractures, adjacent body fractures, and severe neural deficits which require canal decompression [23].…”

Minimally Invasive Spinal Surgery for Adult Spinal Deformity

“…For rigid lumbosacral fixation in cMISS, Wang et al [ 39 ] reported feasibility and safety of percutaneous iliac screws placement without extensive muscle exposure. Fluoroscopic guidance is essential and recent advances for image-guided surgery with navigation or robotic guidance enhance safety and accuracy of the surgery [ 40 , 41 ].…”

Accuracy of Percutaneous Pedicle Screw Insertion Technique with Conventional Dual Fluoroscopy Units and a Retrospective Comparative Study Based on Surgeon Experience

“…Whereas the dual fluoroscopy technique contributed to the high accuracy of screw placement on the axial plane and the optimal location of the screw top within the vertebra on lateral imaging, 12 it had a disadvantage of requiring more radiation exposure. 22 Without an expensive imaging support system, the technique of PPS insertion using dual fluoroscopy units is fairly accurate. However, the higher radiation exposure when using this technique compared with a navigation system is one important limitation.…”