Atlantoaxial facet fixation using cervical facet cage: technical case report and review of the literature.

In 1994, the use of interfacet spacer placement was for joint distraction, reduction, and fusion to supplement atlantoaxial or occipitocervical fixation. Here, we present a unique case of bilateral atlantoaxial interfacet fixation using cervical facet cages (CFC) in a pediatric patient with basilar invagination. In addition, we review the literature on atlantoaxial facet fixation. We present a 12-year-old boy with Wiedemann-Steiner syndrome who presented with multiple episodes of sudden neck jerking, described as in response to a sensation of being shocked, and guarding against neck motion, found to have basilar invagination with cervicomedullary compression. He underwent an occiput to C3 fusion with C1-C2 CFC fixation. We also conducted a literature review identifying all publications using the following keywords: "C1" AND "C2" OR "atlantoaxial" AND "facet spacer" OR "DTRAX." The patient demonstrated postoperative radiographic reduction of his basilar invagination from 6.4 to 4.1 mm of superior displacement above the McRae line. There was a 4.5 mm decrease in the atlantodental interval secondary to decreased dens retroflexion. His postoperative course was complicated by worsening of his existing dysphagia but was otherwise unremarkable. His neck symptoms completely resolved. We illustrate the safe use of CFC for atlantoaxial facet distraction, reduction, and instrumented fixation in a pediatric patient with basilar invagination. Review of the literature demonstrates that numerous materials can be safely placed as a C1-C2 interfacet spacer including bone grafts, titanium spacers, and anterior cervical discectomy and fusion cages. We argue that CFC may be included in this arsenal even in pediatric patients.

C-arm Free O-arm Navigated Posterior Atlantoaxial Fixation in Down Syndrome: A Technical Note.

The surgical treatment of pediatric atlantoaxial subluxation (AAS) in Down syndrome (DS) remains technically challenging due to radiation exposure and complications such as vertebral artery injury and nonunion. The established treatment is fixation with a C1 lateral mass screw and C2 pedicle screw (modified Goel technique). However, this technique requires fluoroscopy for C1 screw insertion. To avoid exposing the operating team to radiation we present here a new C-arm free O-arm navigated surgical procedure for pediatric AAS in DS. A 5-year-old male DS patient had neck pain and unsteady gait. Radiograms showed AAS with an atlantodental interval of 10 mm, and irreducible subluxation on extension. CT scan showed Os odontoideum and AAS. MRI demonstrated spinal cord compression between the C1 posterior arch and odontoid process. We performed a C-arm free O-arm navigated modified Goel procedure with postoperative halo-vest immobilization. At oneyear follow-up, good neurological recovery and solid bone fusion were observed. The patient had no complications such as epidural hematoma, infection, or nerve or vessel injury. This novel procedure is a useful and safe technique that protects surgeons and staff from radiation risk.

Innovative C-Arm-Free Navigation Technique for Posterior Spinal Fixation for Atlantoaxial Subluxation: A Technical Note.

Study design: Technical note. Objectives: To present a novel C-arm-free technique guided by navigation to insert and place a C1 lateral mass screw. Background and Objectives: Atlantoaxial subluxation (AAS) is a relatively common sequelae in patients with rheumatoid arthritis (RA) and upper cervical trauma. If they present with severe symptoms, surgical intervention such as posterior fusion is indicated. The established treatment for AAS is fixation with a C1 lateral mass screw and C2 pedicle screw (modified Goel technique) to achieve bony fusion. However, this technique requires fluoroscopy for C1 screw insertion. To avoid exposing the operating team to radiation, we present here a novel C-arm-free C1 lateral mass screw insertion technique for AAS. Materials and Methods: A 67-year-old man was referred to our hospital with neck pain, quadriparesis, and clumsiness and numbness of both upper and lower limbs. He had undergone C3-6 posterior fusion previously in another hospital. In physical examination, he had severe muscle weakness of bilateral upper limbs and hypoesthesia of all four limbs. He had hyper-reflexia of bilateral lower limbs and pollakiuria. His Japanese orthopedic score was 8 points out of 17. Preoperative radiograms showed AAS with an atlantodental interval (ADI) of 7 mm. MRI indicated retro-odontoid pseudotumor and severe spinal cord compression at the C1-2 level. The patient underwent posterior atlantoaxial fixation under navigation guidance. To prevent epidural bleeding during the insertion and placement of a C1 lateral mass screw, we have here defined a novel screw insertion technique. Results: The surgical time was clocked as 127 min and blood loss was 100 mL. There were no complications per-operatively or in the postoperative period. The patient showed almost full recovery (JOA 16/17) at two months follow-up and a solid bony fusion was noticed in the radiograms at one year follow-up. Conclusions: This novel surgical procedure and C1 lateral mas screw placement technique is a practical and safe method in recent advances of AAS treatment. Procedurally, the technique helps prevent epidural bleeding from the screw entry point and also allows for proper C1 screw insertion under navigation guidance without exposing surgeons and staff to the risk of fluoroscopic radiation.

C1-C2 intraarticular distraction with anterior cervical cages for basilar invagination realignment: Operative technique nuances and review of literature.

Neurosurgical management of basilar invagination (BI) has traditionally been aimed at direct cervicomedullary decompression through transoral dens resection or suboccipital decompression with supplemental instrumented fixation. Dr. Goel introduced chronic atlantoaxial dislocation (AAD) as the etiology in most cases of BI and described a technique for distracting the C1-C2 joint with interfacet spacers to achieve reduction and anatomic realignment. We present our modification to Goel's surgical technique, in which we utilize anterior cervical discectomy (ACD) cages as C1-C2 interfacet implants. A young adult male presented to our institution with BI, cervicomedullary compression, occipitalization of C1, and Chiari 1 malformation. There was AAD of C1 over the C2 lateral masses. This reduced some with preoperative traction. He underwent successful C1-C2 interfacet joint reduction and arthrodesis with anterior cervical discectomy (ACD) cages and concomittant occiput to C2 instrumented fusion. BI can be effectively treated through reduction of AAD and by utilizing ACD cages as interfacet spacers.

Unilateral facet fixation as a salvage procedure: Report of two cases with cervical primary bone tumors with extensive bone destruction.

We describe cases of two patients with primary cervical bone tumors that resulted in extensive destruction of bones of the region. In the first patient, the tumor and its growth resulted in the destruction of C3-C5 vertebral bodies and the unilateral destruction of facets and pedicles. In the second case, there was focal destruction of the body and odontoid process and unilateral pedicle and facet of C2. Tumor resection and spinal stabilization were the aims of the surgery. In both cases, unilateral fixation of facets was done. In the first patient, multi-segmental transarticular fixation by Camille's technique was done, and in the second patient, unilateral lateral mass plate and screw fixation was done by the Goel technique. Solid bone fusion of spinal segments was observed at more than a 2-year follow-up in both cases. Based on this experience, it appears that unilateral facetal fixation can provide firm stability and can be used when other more frequently and popularly used techniques are either not available or possible.

Vision Loss Following Vertebral Artery Injury during Surgery for Atlantoaxial Instability.

Background: A number of complications following surgery aimed at atlantoaxial fixation have been reported. However, there is no report in the literature describing visual loss following vertebral artery injury. Objective: Vision loss as a complication of vertebral artery injury during surgery for atlantoaxial fixation is reported. Material and Methods: This is a report of two patients who were operated for atlantoaxial instability by the Goel technique of atlantoaxial fixation. During surgery, there was an injury to the vertebral artery and the artery had to be sacrificed. Results: Both patients suffered severe visual loss following surgery. One patient had a partial visual recovery that started within few days of surgery while the other patient remained completely blind. Conclusions: Although rare, visual loss can be a complication of vertebral artery sacrifice during surgery for atlantoaxial stabilization.

C1 lateral mass reduction screws for treating atlantoaxial dislocations: Bringing ease by modification.

Objective: The C1-C2 fixation technique revolutionized the management of complex craniovertebral junction (CVJ) anomalies. Presently used polyaxial screw and rod systems have inadvertent technical difficulties in rod fitting and reduction of atlantoaxial dislocations (AAD) requiring forceful joint handling. The purpose of this study is to analyze the use of a specially designed "reduction screw" in C1 lateral mass in C1-C2 fixation for treating AAD with or without basilar invagination (BI). Study Design: This is a retrospective cohort study in which long lateral mass reduction screws were used for C1-C2 fixation. Materials and Methods: Eighteen patients diagnosed with congenital AAD with or without BI treated with C1-C2 fixations using C1 reduction lateral mass were included in the study. The outcome was measured clinically by the modified Japanese Orthopedic Association score and radiologically by conventional craniometric indices. Results: Among all cases included in the study, 72% (13/18) are males and 18% (5/18) are females with average age at presentation of 33.5 years. Among 18 cases of AAD, 84% (15/18) of patients have BI, 22% (4/18) have Chiari Type 1 malformation, and one patient has Klipple-Feil syndrome. Symptomatic improvement is noted in all patients following surgery. Adequate reduction of AAD with normalization of radiological indices was also achieved in all 18 (100%) patients. Conclusion: C1 lateral mass reduction screw in C1-C2 fixation helps in reduction of AAD and BI (Type A) even in difficult cases of CVJ anomalies with intraoperative technical ease, reduced operative time, no need for special instruments or complex maneuvers, and avoiding potential neurological injury.

Vertebral artery mobilization for C1-2 reduction and fixation.

Craniocervical instability due to chronic atlantoaxial dissociation presents the challenge of providing adequate decompression, reduction, and fixation to promote long-term stability while avoiding iatrogenic vertebral artery dissection or entrapment. The authors present one patient with chronic atlantoaxial dissociation and basilar invagination treated via Goel's technique and with bilateral vertebral artery mobilization. There was substantial decompression and reduction postoperatively and the patient was discharged with a stable examination. Vertebral artery mobilization at the C1-2 junction can be safely performed via a standard midline suboccipital incision and dissection without vertebral artery injury. The video can be found here: https://youtu.be/VS1Mt1dBLO4.

Clinicoradiological outcomes of Goel and Harms fixation for atlantoaxial instability: An institutional experience.

BACKGROUND: Few studies have reported on the long-term outcomes of Goel and Harms C1-C2 fusions in the Asian population. METHODS: This was a retrospective analysis of 53 patients undergoing Goel and Harms fixation (2010 -2018). Clinical outcomes were assessed utilizing the neck disability index (NDI), Japanese Orthopedic Association (JOA) score, and visual analog scale (VAS). Outcomes were then correlated with fusion rates (using dynamic X-rays), atlanto-dens interval (ADI), and space available for cord (SAC) data. RESULTS: The study's 53 patients averaged 49.98 years of age and included 42 males and 11 females. The mean preoperative versus postoperative scores on multiple outcome measures showed NDI 31.62 ± 11.05 versus decreased to 8.68 ± 3.76 post, mean JOA score (e.g., in 41 patients with myelopathy) improved from 13.20 ± 3.96 to 15.2 ± 2.17, and the mean VAS decreased from 4.85 ± 1.03 to 1.02 ± 0.87 and showed restoration of the ADI (1.96 ± 0.35 mm) and SAC (20.42 ± 0.35 mm). A 98.13% rate of C1-C2 fusion was achieved at 12 postoperative months. CONCLUSION: Goel and Harms technique for C1-C2 fusion resulted in both good clinical and radiological outcomes.

Lessons learned from surgical management of craniovertebral instability in Morquio syndrome: A series of four unusual cases.

Morquio syndrome (MS) is an autosomal recessive defect caused by the deficiency of N-acetylgalactosamine-6-sulfatase. Odontoid hypoplasia, periodontoid soft tissue deposition, and cervical stenosis lead to myelopathy and quadriparesis in these patients. Craniovertebral junction instability in MS possesses a surgical challenge as bones are yet to completely ossify. The atlantoaxial dislocation (AAD) is reducible, and the need of transoral decompression for the soft tissue deposition ventral to odontoid is debatable. We present a series of four cases (mean age 4.3 ± 0.4 years) operated through posterior-only approach (n = 2, C1-lateral mass to C2 pars-interarticularis [Goel's technique]; n = 1 sublaminar wiring followed by C1-lateral mass to C2 pars-interarticularis; and n = 1 suboccipital plate with pars-interarticularis of C2 screw and pedicle of C3 and rod fixation). All patients had acceptable outcome and doing well at the last follow-up (12-96-follow-up). None of our patient needed transoral decompression. Patients with MS frequently manifest with spastic quadriparesis at an early age due to reducible AAD. Early surgical fixation with posterior C1-C2 screw and rod technique is recommended for the favorable surgical outcome and long-term stability of the cervical spine.

Posterior atlantoaxial fusion: a comprehensive review of surgical techniques and relevant vascular anomalies.

Posterior atlantoaxial fusion is an important surgical technique frequently used to treat various pathologies involving the cervical 1-2 joint. Since the beginning of the 20th century, various fusion techniques have been developed with improved safety profile, higher fusion rates, and superior clinical outcome. Despite the advancement of technology and surgical techniques, posterior C1-2 fusion is still a technically challenging procedure given the complex bony and neurovascular anatomy in the craniovertebral junction (CVJ). In addition, vascular anomalies in this region are not uncommon and can lead to devastating neurovascular complications if unrecognized. Thus, it is important for spine surgeons to be familiar with various posterior atlantoaxial fusion techniques along with a thorough knowledge of various vascular anomalies in the CVJ. Intimate knowledge of the various surgical techniques in combination with an appreciation for anatomical variances, allows the surgeon develop a customized surgical plan tailored to each patient's particular pathology and individual anatomy. In this article, we aim to provide a comprehensive review of existing posterior C1-2 fusion techniques along with a review of common vascular anomalies in the CVJ.

Hybrid and double insurance atlantoaxial facetal fixation.

The authors report a case of a 19-year-old female patient having basilar invagination with complex musculoskeletal abnormalities wherein atlantoaxial fixation was done with a combination of Goel and Magerl techniques on a single articulation on one side and two transarticular screws (Magerl technique) were deployed on the contralateral side articulation. The combination of Goel and Magerl techniques used in a novel fashion resulted in strong fixation and provided an environment for bone fusion. The special joint architecture and location of facet of atlas anterior and rostral to the facet of axis in the form of facetal-spondyloptosis were used to advantage as it provided a direct screw trajectory for transarticular screw insertion. The patient recovered after surgery in her neurological function. Craniovertebral junction realignment could be observed. Solid bone fusion was observed after 8 months of the surgical procedure.