Treatment of pediatric atlantoaxial instability with traditional and modified Goel–Harms fusion constructs

Abstract

There are several treatment options for rigid fixation at C1-C2 including Brooks and Gallie type wired fusions and C1-2 transarticular screws. The use of a GoelHarms type fusion, a construct with C1 lateral mass screws and C2 pedicle screws, has not been extensively described in pediatric patients. Here, we describe its relatively safe and effective use for treating pediatric patients by retrospective chart review of patients treated by the senior author for atlantoaxial instability with a Goel-Harms-type constructs during a 3-year period (2005)(2006)(2007). Six patients were treated using Goel-Harms-type constructs. Five patients were treated utilizing a construct containing C1 lateral mass screws and C2 pedicle screws; one patient was treated using construct containing C1 lateral mass screws and C2 trans-laminar screws. The patients ranged in age from 7 to 17 years old (mean 12.7). All patients had findings of an os odontoideum on CT scans and three of the six patients had T2 hyperintensity on MRI. Three of the six patients presented with transient neurologic deficits: quadraplegia in two patients and paresthesias in two patients. In each patient C1 lateral mass and C2 screws were placed and the subluxation was reduced to attain an anatomical alignment. No bone grafts were harvested from the iliac crest or rib. Local morsalized bone and sub-occipital skull graft was used. All patients tolerated the procedure well and were discharged home on post-operative day 3-4. The patients wore a hard cervical collar and no halo-vests were needed. All patients had solid fusion constructs and normal alignment on post-operative imaging studies performed on average 14 months post-operatively (range: 7-29). The results demonstrated that Goel-Harms fusions are a relatively safe and effective method of treating pediatric patients with atlantoaxial instability and are not dependent on vertebral anatomy or an intact ring of C1. Follow-up visits and studies in this limited series of patients demonstrated solid fusion constructs and anatomical alignment in all patients treated.

Complications and outcomes of posterior fusion in children with atlantoaxial instability

“…Similarly, some studies reported that the C1 lateral screw and C2 pedicle screw technique (Goel-Harms constructs [4,5]) provide stabilization and promotes fusion in pediatric patients with AAI [9][10][11][12][13]. Also, unlike wiring techniques, C1-2 transarticular screw and Goel-Harms constructs do not require that the patient be placed in a halo vest postoperatively [13]. Likewise, Leonard et al [15] reported successful results with rigid fixation in three children in whom bilateral crossing C2 translaminar screws were placed to avoid vertebral artery injury.…”

“…C1-2 transarticular screw fixation (Magerl technique [3]) and its effectiveness in pediatric patients have been described [8,16,17]. Similarly, some studies reported that the C1 lateral screw and C2 pedicle screw technique (Goel-Harms constructs [4,5]) provide stabilization and promotes fusion in pediatric patients with AAI [9][10][11][12][13]. Also, unlike wiring techniques, C1-2 transarticular screw and Goel-Harms constructs do not require that the patient be placed in a halo vest postoperatively [13].…”

“…Magerl et al [3] first proposed the use of C1-C2 transarticular screws in adults, and an alternative technique, namely C1 lateral mass screws and C2 pedicle screws [4,5] or C2 translaminar screws [6] has been reported. More recently, these techniques are being used in pediatric patients [7][8][9][10][11][12][13][14][15][16][17]; however, there are no detailed reports on the risks with these techniques when used in children. Furthermore, the medical community does not fully understand the long-term effects of posterior cervical spine fusion in the skeletally immature spine, and there are only a few published articles on these effects [18,19].…”

C1–2 transarticular screws combined with C1 laminar hooks fixation: a modified posterior atlantoaxial fixation technique and outcome in 72 patients

“…Also, they carry a neurologic risk because sublaminar wires are passed under the C1 arch. Harms technique composed of C1 lateral mass screws coupled to C2 pedicle screws has been reported to be a relatively effective method to provide a solid fusion construct in patients with atlantoaxial instability [14]. From a theoretical biomechanical viewpoint, it still is a one-point fixation, but as the screws are rigidly fixed to the longitudinal members of the construct, its biomechanical properties are probably superior to Gallie fixation and alone C1-2 transarticular fixation [11,14,15], as proved in the current biomechanical study.…”

“…Harms technique composed of C1 lateral mass screws coupled to C2 pedicle screws has been reported to be a relatively effective method to provide a solid fusion construct in patients with atlantoaxial instability [14]. From a theoretical biomechanical viewpoint, it still is a one-point fixation, but as the screws are rigidly fixed to the longitudinal members of the construct, its biomechanical properties are probably superior to Gallie fixation and alone C1-2 transarticular fixation [11,14,15], as proved in the current biomechanical study. C1-2 transarticular screws have been reported to have contributed to a solid stability in patients with atlantoaxial instability [11,[14][15][16][17][18][19]; Also, the results from the author's previous biomechanical study have proved that alone C1-2 transarticular screw can provide much better biomechanical stability compared to Gallie fixation, but its biomechanical stability is inferior to TA ?…”