Cranio-cervical decompression associated with non-instrumented occipito-C2 fusion in children with mucopolysaccharidoses: Report of twenty-one cases

BACKGROUND

Mucopolysaccharidosis (MPS) is a multisystemic storage disorder of glycosaminoglycan deposits. Infiltration of the dura mater and supporting ligaments caused spinal cord compression and consecutive myelopathy, especially at the cranio-cervical junction (CCJ). Craniocervical instability and posterior decompression often raise the problem of fixation in children. The main purpose of this paper was to report the result of an original technique of occipito-cervical arthrodesis using a cranial halo-cast system in pediatric population.

METHODS

We recorded 21 patients with cervical myelopathy. All of them had spinal cord decompression by enlargement of the foramen magnum, C1 laminectomy, and occipito-C2 fusion using corticocancellous bone graft. Only one child has an extended laminectomy from C1 to C3. The occiput-C2 arthrodesis was stabilized by the cranial halo-cast system. This immobilization was performed preoperatively and kept for three months then switched to rigid cervical collar. Clinical assessment, including the Goel grade and mJOA, radiographs and magnetic resonance imaging were performed before surgery. The occipito-cervical arthrodesis was controlled by standard X-rays and CT scan.

RESULTS

According to the type of mucopolysaccharidosis, the patients were divided into MPS type I: n= 3, II: n=7, IV: n=11. The mean age of patients at surgery was 6.76 years. All mucopolysaccharidoses cases required a foramen magnum decompression by craniectomy, C1 laminectomy and occipito-C2 arthrodesis. As major complications, a child had immediate post-operative paraplegia due to spinal cord ischemia. The postoperative follow-up ranged from 1.5 to 4 years, with an average of 3.3 years. The average preoperative mJOA score was 8.9, and it improved to 14 points at the last follow-up.

CONCLUSIONS

Satisfactory fusion and good clinical results were obtained with the 2-stage approach to CCJ anomalies.

Atlantoaxial Dislocation with Bony Fusion of C1/2 Facet Joints Treated with Posterior Joint Release, Distraction and Reduction

Introduction

Technical Note

Conclusions

Two-Stage Approach for Unstable Pediatric Craniocervical Junction Anomalies with a Halo Vest and Delayed Occipitocervical Fusion: Technical Note, Case Series, and Literature Review

OBJECTIVE

Malformations in the craniocervical junction (CCJ) are rare in the pediatric population but often need surgical treatment. We present a pediatric case series of patients treated with a 2-stage surgical approach with a halo vest and occipitocervical fusion and review complications and outcomes.

METHODS

A retrospective analysis of a single-center case series was performed. Pediatric patients affected by congenital craniocervical junction anomalies and treated with a 2-stage approach were included. A halo vest was implanted in the first surgery, and ambulatory progressive reduction was performed. When a favorable anatomic situation was observed, arthrodesis was performed. Safety analysis was undertaken by analyzing the incidence of complications in both procedures. Effectivity analysis was carried out analyzing radiologic and clinical outcome (Goel grade and modified Japanese Orthopaedic Association score). Student t test was used for statistical analysis.

RESULTS

Sixteen cases were included. Mean age of patients was 9.38 years. Safety analysis showed 2 halo loosenings, 1 pin infection, 2 wound infections, 1 cerebrospinal fluid leak, and 2 delayed broken rods. No major complications were observed. Radiologic analysis showed an improvement in the tip of the odontoid process to the McRae line distance (from -3.26 mm to -6.16 mm), atlantodental interval (from 3.05 mm to 1.88 mm), clival-canal angle (from 134.61° to 144.38°), and cervical kyphosis (from 6.39° to 1.54°). Clinical analysis also showed improvement in mean Goel grade (from 1.75 to 1.44) and modified Japanese Orthopaedic Association score (from 15.12 to 16.41).

CONCLUSIONS

The 2-stage approach was a suitable and effective treatment for craniocervical junction anomalies in pediatric patients.

Open Reduction and Decompression of Atlantoaxial Subluxation with Basilar Impression Due to Grisel Syndrome Using the Cervical Management Base Unit

BACKGROUND

Intraoperative manipulation of the craniocervical junction with the Cervical Management Base Unit (CMBU) has been used as an adjunct for achieving optimal anatomic alignment during instrumented fusion procedures in a variety of disease settings. Here, we present our experience using the CMBU as a supplement to achieving a successful reduction and fixation of a reducible craniocervical subluxation with associated basilar impression/medullary compression in the setting of Grisel syndrome.

CASE DESCRIPTION

Under fluoroscopy and neuromonitoring guidance, the elevator and axial translation mechanisms of the CMBU safely allowed for presurgical assessment of reducibility and facilitated complete reduction of the deformity with restitution of a normal atlantodental interval, spinolaminar line, and clivoaxial angle. Magnetic resonance imaging acquired 1 month after surgery and antibiotic therapy showed resolution of a large epidural abscess in the region of the dens and no evidence of residual neural impingement. Upright plain films at 9 months showed maintenance of the desired craniocervical alignment.

CONCLUSIONS

Intraoperative manipulation of the craniocervical junction using the CMBU, when implemented under fluoroscopy and neuromonitoring, can safely facilitate an enduring anatomic correction of craniocervical deformity in the setting of Grisel syndrome. The dynamic utility of the CMBU for translation of the head and neck obviated the need to apply forces directly to hardware-bone interfaces, and its utility may extend to craniocervical disorders of other etiologies, especially those of a reducible nature and in the setting of poor bone quality and joint laxity.

Influence of Postoperative O-C2 Angle on the Development of Dysphagia After Occipitocervical Fusion Surgery: Results from a Retrospective Analysis and Prospective Validation

BACKGROUND

Postoperative dysphagia is a known complication of anterior cervical surgery, but its incidence and possible mechanisms are seldom reported after occipitocervical fusion (OCF). Our objective was to study the relationship between craniocervical alignment and the development of dysphagia after OCF for the treatment of basilar invagination with atlantoaxial instability.

METHODS

The study consisted of a retrospective series and a prospective series. Seventy-eight patients who underwent OCF (30 male, 48 female) were reviewed in the retrospective series. The presence and duration of postoperative dysphagia were recorded with an in-person questionnaire or telephone interview. Sagittal reconstructed computed tomography images before and after the procedure were collected. The O-C2 angle and C2-C7 angle were measured. The relationship of these parameters and their influence to the incidence of dysphagia were analyzed. The patients were grouped according to whether they developed postoperative dysphagia (group A) or not (group B). A prospective case series of 27 patients (group C) were reported to verify the influence of O-C2 angle on postoperative dysphagia.

RESULTS

In the retrospective case series, 19 patients (24.4%) complained of postoperative dysphagia after OCF. The change in the O-C2 angle was significantly lower in group A than in group B (P < 0.001). In the prospective case series, only 1 patient (3.7%) complained of postoperative dysphagia.

CONCLUSIONS

O-C2 angle plays an important role in the development of postoperative dysphagia after OCF procedure. Careful intraoperative alignment of the O-C2 angle may help to reduce the incidence and severity of postoperative dysphagia after OCF.