Morphological characteristics of cervical spine in patients with athetoid cerebral palsy and the accuracy of pedicle screw placement.
METHODS
A retrospective study.


OBJECTIVE
To investigate the morphology of the cervical spine in patients with athetoid cerebral palsy (CP), and to evaluate its relationship with the breach of cervical pedicle screws.


BACKGROUND
Cervical pedicle screws have been increasingly used in surgery for patients with CP, but screw misplacement is not uncommon. Although the altered morphology of the cervical spine in patients with CP may result in this high breach rate, few studies have examined the cervical pedicle profile.


METHODS
We retrospectively analyzed 31 patients with cervical myelopathy with CP, as well as 30 patients with cervical spondylotic myelopathy (CSM), who underwent posterior decompression surgery. The pedicle outer diameter, inner diameter, transverse angle and lateral mass deformity were investigated by obtaining preoperative computed tomographic scans. The accuracy of the placement of 56 pedicle screws used in fusion surgery for 12 patients with CP was also analyzed using postoperative computed tomographic scans.


RESULTS
The outer diameter of the pedicle in CP was in the range from 3.3 to 9.6 mm, and was larger than that in CSM at all cervical levels except for C7. Pedicle sclerosis was more frequently observed in CP than in CSM (23% vs. 7.3%, P < 0.001). The transverse angle at C3 and C4 was larger, and lateral mass deformity was more frequently observed in CP than in CSM. The critical breach of pedicle screws in CP was found in 29%. A multivariate analysis revealed that pedicle sclerosis was associated with an increased risk of breach (odds ratio: 6.3; 95% confidence interval: 1.03-39.0; P = 0.047).


CONCLUSIONS
The pedicle diameter in patients with CP was relatively large, but pedicle sclerosis, a wide transverse angle and lateral mass deformity were frequently observed. Sclerotic pedicles were associated with a higher risk of critical breach.


METHODS
N/A.
*Department of Orthopaedic Surgery, Sensory and Motor System Medicine, Surgical Sciences, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan; and †Department of Orthopaedics, Jichi Medical University, Shimotsuke, Japan.
So
S
Kato
Naoki
N
Shoda
Hirotaka
H
Chikuda
Atsushi
A
Seichi
Katsushi
K
Takeshita
D000328:Adult; D000368:Aged; D001863:Bone Screws; D002547:Cerebral Palsy / Q000150:complications*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D016009:Chi-Square Distribution; D019299:Decompression, Surgical / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011183:Postoperative Complications / Q000209:etiology; D011474:Prosthesis Design; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012598:Sclerosis; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome