Clin Orthop Surg.  2013 Sep;5(3):225-229. 10.4055/cios.2013.5.3.225.

Lumbosacral Fixation Using the Diagonal S2 Screw for Long Fusion in Degenerative Lumbar Deformity: Technical Note Involving 13 Cases

• Park YS
• Kim HS
• Baek SW
• Lee SH

• KMID: 1705549
• DOI: http://doi.org/10.4055/cios.2013.5.3.225

Abstract

Placing instrumentation into the ilium has been shown to increase the biomechanical stability and the fusion rates, but it has some disadvantages. The diagonal S2 screw technique is an attractive surgical procedure for degenerative lumbar deformity. Between 2008 and 2010, we carried out long fusion across the lumbosacral junction in 13 patients with a degenerative lumbar deformity using the diagonal S2 screws. In 12 of these 13 patients, the lumbosacral fusion was graded as solid fusion with obvious bridging bone (92%). One patient had a rod dislodge at one S2 screw and breakage of one S1 screw and underwent revision nine months postoperatively. So, we present alternative method of lumbopelvic fixation for long fusion in degenerative lumbar deformity using diagonal S2 screw instead of iliac screw.

Keyword

Long fusion; Diagonal S2 screw; Iliac screw; Degenerative lumbar deformity

MeSH Terms

Aged
*Bone Screws
Cohort Studies
Female
Humans
Ilium/surgery
Lumbar Vertebrae/*abnormalities/*surgery
Male
Middle Aged
Sacrum/surgery
Spinal Fusion/adverse effects/*instrumentation/methods
Treatment Outcome

Figure

• 

  Fig. 1 Entry point of the S2 alar screw (arrow) and the midpoint of the line from the medial margin of the S1 dorsal foramen and the medial margin of the S2 dorsal foramen.

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  Fig. 2 (A) The lateral trajectory of the S2 alar screw varied somewhat among patients but was typically between 30 and 35 degrees in the lateral planes. It did not penetrate the sacroiliac joint laterally or the S1 ventral foramen medially. (B) The superior trajectory of the S2 alar screw was a longer screw insertion and did vary somewhat among patients, but was typically between 15 and 20 degrees in the superior planes. It did not penetrate the anterior cortex as this could cause impingement of the L5 nerve root and injury to the internal iliac vessels.

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  Fig. 3 Two years postoperatively, there was no evidence of screw loosening or pseudarthrosis at the lumbosacral junction.

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