Recent literature describing complications associated with spinopelvic fixation with iliac screws in adult patients has been limited but has suggested high complication rates. The authors’ objective was to report their experience with iliac screw fixation in a large series of patients with a 2-year minimum follow-up.
Of 327 adult patients undergoing spinopelvic fixation with iliac screws at the authors’ institution between 2010 and 2015, 260 met the study inclusion criteria (age ≥ 18 years, first-time iliac screw placement, and 2-year minimum follow-up). Patients with active spinal infection were excluded. All iliac screws were placed via a posterior midline approach using fluoroscopic guidance. Iliac screw heads were deeply recessed into the posterior superior iliac spine. Clinical and radiographic data were obtained and analyzed.
Twenty patients (7.7%) had iliac screw–related complication, which included fracture (12, 4.6%) and/or screw loosening (9, 3.5%). No patients had iliac screw head prominence that required revision surgery or resulted in pain, wound dehiscence, or poor cosmesis. Eleven patients (4.2%) had rod or connector fracture below S1. Overall, 23 patients (8.8%) had L5–S1 pseudarthrosis. Four patients (1.5%) had fracture of the S1 screw. Seven patients (2.7%) had wound dehiscence (unrelated to the iliac screw head) or infection. The rate of reoperation (excluding proximal junctional kyphosis) was 17.7%. On univariate analysis, an iliac screw–related complication rate was significantly associated with revision fusion (70.0% vs 41.2%, p = 0.013), a greater number of instrumented vertebrae (mean 12.6 vs 10.3, p = 0.014), and greater postoperative pelvic tilt (mean 27.7° vs 23.2°, p = 0.04). Lumbosacral junction–related complications were associated with a greater mean number of instrumented vertebrae (12.6 vs 10.3, p = 0.014). Reoperation was associated with a younger mean age at surgery (61.8 vs 65.8 years, p = 0.014), a greater mean number of instrumented vertebrae (12.2 vs 10.2, p = 0.001), and longer clinical and radiological mean follow-up duration (55.8 vs 44.5 months, p < 0.001; 55.8 vs 44.6 months, p < 0.001, respectively). On multivariate analysis, reoperation was associated with longer clinical follow-up (p < 0.001).
Previous studies on iliac screw fixation have reported very high rates of complications and reoperation (as high as 53.6%). In this large, single-center series of adult patients, iliac screws were an effective method of spinopelvic fixation that had high rates of lumbosacral fusion and far lower complication rates than previously reported. Collectively, these findings argue that iliac screw fixation should remain a favored technique for spinopelvic fixation.
Correspondence James H. Nguyen: University of Virginia Health System, Charlottesville, VA. firstname.lastname@example.org.
INCLUDE WHEN CITING Published online February 1, 2019; DOI: 10.3171/2018.9.SPINE18239.
Disclosures Christopher I. Shaffrey: consultant: Medtronic, NuVasive, Zimmer-Biomet, and K2M; royalties: Medtronic, NuVasive, and Zimmer-Biomet; stockholder: NuVasive; and grants: NIH, DOD, and NACTN.
Justin S. Smith: royalties: Zimmer Biomet; consultant: Zimmer Biomet, Cerapedics, NuVasive, K2M, and AlloSource; honoraria: Zimmer Biomet, NuVasive, and K2M; research support: DePuy Synthes and ISSGF; and fellowship support: NREF and AOSpine.
ChoWMasonJRSmithJSShimerALWilsonASShaffreyCI: Failure of lumbopelvic fixation after long construct fusions in patients with adult spinal deformity: clinical and radiographic risk factors: clinical article. J Neurosurg Spine19:445–4532013
CunninghamBWLewisSJLongJDmitrievAELinvilleDABridwellKH: Biomechanical evaluation of lumbosacral reconstruction techniques for spondylolisthesis: an in vitro porcine model. Spine (Phila Pa 1976)27:2321–23272002
ElderBDIshidaWLoSLHolmesCGoodwinCRKosztowskiTA: Use of S2-alar-iliac screws associated with less complications than iliac screws in adult lumbosacropelvic fixation. Spine (Phila Pa 1976)42:E142–E1492017
ElderBD, IshidaW, LoSL, HolmesC, GoodwinCR, KosztowskiTA, : Use of S2-alar-iliac screws associated with less complications than iliac screws in adult lumbosacropelvic fixation. 42:E142–E149, 201710.1097/BRS.0000000000001722)| false
GulerUO, CetinE, YamanO, PelliseF, CasademutAV, SabatMD, : Sacropelvic fixation in adult spinal deformity (ASD); a very high rate of mechanical failure. 24:1085–1091, 201510.1007/s00586-014-3615-125323138)| false
HoernschemeyerDGPashuckTDPfeifferFM: Analysis of the S2 alar-iliac screw as compared with the traditional iliac screw: does it increase stability with sacroiliac fixation of the spine?Spine J17:875–8792017
HoernschemeyerDG, PashuckTD, PfeifferFM: Analysis of the S2 alar-iliac screw as compared with the traditional iliac screw: does it increase stability with sacroiliac fixation of the spine?17:875–879, 201710.1016/j.spinee.2017.02.00128185981)| false
IlyasHPlaceHPuryearA: A comparison of early clinical and radiographic complications of iliac screw fixation versus S2 alar iliac (S2AI) fixation in the adult and pediatric populations. J Spinal Disord Tech28:E199–E2052015
IlyasH, PlaceH, PuryearA: A comparison of early clinical and radiographic complications of iliac screw fixation versus S2 alar iliac (S2AI) fixation in the adult and pediatric populations. 28:E199–E205, 201510.1097/BSD.0000000000000222)| false
IshidaWElderBDHolmesCGoodwinCRLoSFKosztowskiTA: S2-alar-iliac screws are associated with lower rate of symptomatic screw prominence than iliac screws: radiographic analysis of minimal distance from screw head to skin. World Neurosurg93:253–2602016
IshidaW, ElderBD, HolmesC, GoodwinCR, LoSF, KosztowskiTA, : S2-alar-iliac screws are associated with lower rate of symptomatic screw prominence than iliac screws: radiographic analysis of minimal distance from screw head to skin. 93:253–260, 20162731930810.1016/j.wneu.2016.06.042)| false
IshidaWElderBDHolmesCLoSLGoodwinCRKosztowskiTA: Comparison between S2-alar-iliac screw fixation and iliac screw fixation in adult deformity surgery: reoperation rates and spinopelvic parameters. Global Spine J7:672–6802017
KimYJBridwellKHLenkeLGRhimSChehG: Pseudarthrosis in long adult spinal deformity instrumentation and fusion to the sacrum: prevalence and risk factor analysis of 144 cases. Spine (Phila Pa 1976)31:2329–23362006
KimYJ, BridwellKH, LenkeLG, RhimS, ChehG: Pseudarthrosis in long adult spinal deformity instrumentation and fusion to the sacrum: prevalence and risk factor analysis of 144 cases. 31:2329–2336, 20061698546110.1097/01.brs.0000238968.82799.d9)| false
LeeMC, JarvisC, SolomitoMJ, ThomsonJD: Comparison of S2-alar and traditional iliac screw pelvic fixation for pediatric neuromuscular deformity. 18:648–654, 201810.1016/j.spinee.2017.08.25328870838)| false
LiuGHasanMYWongHK: The subcrestal iliac-screw: a technical note describing a free hand, in-line, low profile iliac screw insertion technique to avoid side-connector use and reduce implant complications. Spine (Phila Pa 1976)43:E68–E742018
OʼShaughnessyBA, LenkeLG, BridwellKH, ChoW, ZebalaLP, ChangMS, : Should symptomatic iliac screws be electively removed in adult spinal deformity patients fused to the sacrum?37:1175–1181, 20122214629110.1097/BRS.0b013e3182426970)| false
RayWZ, RavindraVM, SchmidtMH, DaileyAT: Stereotactic navigation with the O-arm for placement of S-2 alar iliac screws in pelvic lumbar fixation. 18:490–495, 201310.3171/2013.2.SPINE1281323495892)| false
SmithJS, ShaffreyE, KlinebergE, ShaffreyCI, LafageV, SchwabFJ, : Prospective multicenter assessment of risk factors for rod fracture following surgery for adult spinal deformity. 21:994–1003, 201410.3171/2014.9.SPINE13117625325175)| false
SponsellerPDZimmermanRMKoPSPull Ter GunneAFMohamedASChangTL: Low profile pelvic fixation with the sacral alar iliac technique in the pediatric population improves results at two-year minimum follow-up. Spine (Phila Pa 1976)35:1887–18922010
SponsellerPD, ZimmermanRM, KoPS, Pull Ter GunneAF, MohamedAS, ChangTL, : Low profile pelvic fixation with the sacral alar iliac technique in the pediatric population improves results at two-year minimum follow-up. 35:1887–1892, 201010.1097/BRS.0b013e3181e0388120802390)| false