Original ArticleSurgical Treatment of Occipitocervical Dislocation with Atlas Assimilation and Klippel-Feil Syndrome Using Occipitalized C1 Lateral Mass and C2 Fixation and Reduction Technique
Introduction
In 1912, Klippel-Feil syndrome (KFS) was first described with the classic triad of short neck, low posterior hairline, and limited neck motion. This abnormality is the consequence of failed segmentation of the developing sclerotomes during the third to eighth week of gestation.1 KFS of C2-3 fusion and atlas assimilation have congenital fusions at the occiput-C1 and C2-3 junction, resulting in the greatest amount of C1-2 motion and superior odontoid migration.2 The atlantoaxial hypermobility and concomitant basilar invagination (BI) increased the risk of developing neurologic compromise and the need for surgical intervention.2, 3 For this kind of complex abnormalities, occipitocervical (OC) reduction and fixation has been successful in preventing ventral brainstem impingement.4, 5, 6 However, currently available OC fixation devices mainly rely on instrumentation of the occiput. This occipital screw instrumentation has several limitations because of its variable occipital bone thickness and underling vasculature.7, 8, 9
The ideal system for OC fixation should meet the following requirements: 1) it should concern only the involved segments; 2) no hardware should be inserted into the intracalvarium; 3) it should provide immediate reduction of the deformity until fusion develops without requiring postoperative external halo orthoses; and 4) it should be effective even if the laminae are absent.10 Recently, the occipital condyle screw fixation or fused occipital condyle-C1 lateral mass (C1LM) screw fixation in atlas assimilation has been described,11, 12, 13, 14, 15, 16, 17, 18 which could effectively meet all the requirements of an ideal system. To our knowledge, this technique has not been reported in patients with BI and OC dislocation and C2-3 congenital fusion and atlas assimilation. In this study, we use the modified technique of Harms et al.19 and Goel et al.16, 17, 20 and describe this alternative fixation option of occipitalized C1LM and C2 pedicle screw fixation in 58 such patients and to assess this technique.
Section snippets
Patient Population
From January 2007 to August 2013, 58 symptomatic patients with BI and OC dislocation and C2-3 congenital fusion and atlas assimilation were surgically treated in our institution via C1LM and C2 pedicle/pars screw fixation. The patient population comprised 24 males and 34 females, with ages ranging from 14 to 63 years (mean, 30 years). All patients presented with signs and symptoms of spinal cord dysfunction, and surgical stabilization was indicated. There was a history of a minor trauma on the
Results
In all the 58 cases, complete occipitalization of the atlas was found in 48 cases and partial occipitalization of the atlas (C1 superior articular process with/without anterior or posterior arch) was found in 10. According to the KFS classification proposed by Samartzis et al.,21 type I (a single congenitally fused cervical segment) with fused C2-C3 was noted in 49 cases, type II (multiple noncontiguous fused segments) with fused C2-C3 and C5-C6/C6-C7 was noted in 4, and type III (multiple
Discussion
OC dislocation remains as one of the most serious and concerning problems of the craniovertebral junction (CVJ) and can lead to devastating neurologic deficit or death. In KFS of C2-C3 fusion and occipitalization, the deformity makes the level from occiput to C3 only 1 motion segment and leads to greatest OC instability.2, 3 In such conditions, biomechanical complexity of the CVJ and the scarcity of attachment sites on this region have made internal fixation a challenge. Most OC fixation
Conclusions
To address the poor occipital bone purchase and low OC fusion failure rates for the treatment of KFS and occipitalization with BI and OC dislocation, a novel surgical treatment of occipitalized C1LM and C2 fixation has been developed. By intraoperative manipulative reduction and fixation, impaction of the cervicomedullary junction was relieved without anterior decompression. Our results suggest that this technique is feasible and can be considered as a traditional or salvage fixation procedure.
Acknowledgments
This research was supported by the National Natural Science Foundation of China (numbers 81301274 and 81571350) and the Capital Characteristic Clinical Application Research Funding (Z151100004015009).
References (30)
- et al.
Embryology of the spine and associated congenital abnormalities
Spine J
(2005) - et al.
Posterior realignment of irreducible atlantoaxial dislocation with C1-C2 screw and rod system: a technique of direct reduction and fixation
Spine J
(2013) - et al.
Klippel-Feil syndrome with atlanto-axial dislocation, anomalous vertebral artery, dextrocardia and situs inversus
Clin Neurol Neurosurg
(2013) - et al.
Radiographic assessment of segmental motion at the atlantoaxial junction in the Klippel-Feil patient
Spine (Phila Pa 1976)
(2006) - et al.
Superior odontoid migration in the Klippel-Feil patient
Eur Spine J
(2007) - et al.
Occipital-C2 transarticular fixation for occipitocervical instability associated with occipitalization of the atlas in patients with Klippel-Feil syndrome, using intraoperative 3-dimensional navigation system
Spine (Phila Pa 1976)
(2013) - et al.
Cable-strengthened c2 pedicle screw fixation in the treatment of congenital c2-3 fusion, atlas occipitalization, and atlantoaxial dislocation
Neurosurgery
(2012) - et al.
Pedicle screw combined with lateral mass screw fixation in the treatment of basilar invagination and congenital C2-3 fusion [e-pub ahead of print]
Clin Spine Surg
(2016) - et al.
Complications of fixation to the occiput-anatomical and design implications
Br J Neurosurg
(2004) - et al.
Rigid occipitocervical fusion
J Neurosurg
(1999)
Computed tomography-based morphometric analysis of the human occipital condyle for occipital condyle-cervical fusion
J Neurosurg Spine
Posterior occipitocervical fusion. A preliminary report of a new technique
Spine (Phila Pa 1976)
Occipitocervical fusion via occipital condylar fixation: a clinical case series
J Spinal Disord Tech
Feasibility of occipital condyle screw placement for occipitocervical fixation: a cadaveric study and description of a novel technique
J Spinal Disord Tech
C1 lateral mass screw placement in occipitalization with atlantoaxial dislocation and basilar invagination: a report of 146 cases
Spine (Phila Pa 1976)
Cited by (7)
Efficacy analysis of direct posterior reduction for the treatment of congenital basilar invagination complicated with atlantoaxial dislocation
2023, Chinese Journal of NeurosurgeryResearch on pharyngeal bacterial flora in transoral atlantoaxial operation and the postoperative follow-up study
2022, BMC Musculoskeletal DisordersKlippel-Feil Syndrome: Clinical Presentation and Management
2022, JBJS Reviews
Conflict of interest statement: This research was supported by the National Natural Science Foundation of China (No: 81301274 and 81571350) and the Capital Characteristic Clinical Application Research Funding (Z151100004015009).
Yi-Heng Yin and Guang-Yu Qiao contributed equally to this work.