Clinical and Radiographic Outcomes of Modified Posterior Atlantoaxial Temporary Fixation with Preservation of Semispinalis Cervicis: A Comparative Study

STUDY DESIGN

Retrospective study.

OBJECTIVE

Current studies suggested that the posterior cervical deep muscles should be preserved during the atlantoaxial posterior approach. This study aimed to modify the conventional temporary posterior fixation by preserving the semispinalis cervicis and to evaluate the radiographic and clinical outcomes compared with the conventional technique.

METHODS

Applied anatomical and imaging study were assessed prior to the clinical studies. Thirty patients with odontoid fracture were enrolled. 12 patients underwent modified operation with preservation of semispinalis cervicis (Group P-SSC), and 18 patients underwent conventional approach with detachment of the semispinalis cervicis (Group D-SSC) as controls. Clinical and radiological assessments were evaluated postoperatively, including activities of daily living (ADL), axial symptom scoring system (Ass), cervical range of motion (ROM), and the average atrophy rate of muscles.

RESULTS

All patients experienced fracture healed within 10 months after temporary fixation. At early follow-up, ADL accompanying extension and flexion were significantly different between the two groups. The Ass scores in the Group P-SSC were constantly higher than that in Group D-SSC. Flexion-Extension ROM in Group P-SSC was significantly larger than that of Group D-SSC. The average atrophy rate at the C3 and C5 level in Group P-SSC was 7.62±3.38% and 7.55±3.89%, repectivcly, while 15.67±5.97% and 8.56±4.76% in Group D-SSC, respectively. Significant differences in the atrophy rate were found between groups at C3 level.

CONCLUSIONS

Compared with the conventional technique, the modified surgical technique with preservation of semispinalis cervicis was effective in improving axial symptoms, decreasing the atrophy rate of muscles, and increasing the cervical ROM.

＜Editors' Choice＞ Neck pain after cervical laminoplasty is associated with postoperative atrophy of the trapezius muscle

Cervical laminoplasty is a safe and effective treatment for cervical myelopathy. However, it has a higher frequency of postoperative axial pain than other methods. A variety of causes of postoperative axial pain have been reported, but these have not been fully elucidated. This study aimed to investigate the association between postoperative axial pain and changes in the posterior neck muscles before and after surgery. The study included 93 patients with cervical myelopathy who underwent surgery at our institute between June 2010 and March 2013. The patients with greater preoperative and 1-year postoperative neck pain visual analog scale scores comprised the neck pain group. The cross-sectional area of the cervical posterior extensor muscles and the trapezius muscle were measured by magnetic resonance imaging before and 1 year after surgery at the C3/4, C4/5, and C5/6 levels to compare with neck pain. The total cross-sectional area atrophy rate (C3/C4, C4/C5, and C5/C6) of the trapezius muscle was significantly larger in patients with neck pain (12.8 ± 13.2) than in those without (6.2 ± 14.4; p<0.05). The cross-sectional area atrophy rate of the trapezius muscle at only the C5/6 level was significantly higher in patients with neck pain (16.7 ± 11.7) compared to those without (3.3 ± 14.4; p<0.001). No significant differences were found in the cross-sectional areas of the cervical posterior extensor muscles. Trapezius atrophy, especially at the lower cervical vertebrae, was associated with neck pain after cervical laminoplasty.

Hidden Charcot-Marie-Tooth 1A as Revealed by Peripheral Nerve Imaging

Peripheral nerve imaging techniques have recently increasingly revealed their usefulness. We herein describe a man who had a subacute progression of symptom, diffuse and prominent proximal demyelination and conduction block, suggesting a diagnosis of inflammatory demyelinating polyneuropathy. Additional nerve imaging techniques revealed homogeneous and prominent nerve hypertrophy without proximal accentuation and the findings implied inherited polyneuropathies. Intravenous immunoglobulin was administered, and both the symptoms of weakness and findings of nerve conduction studies (NCS) improved. Subsequent genetic testing unveiled Charcot-Marie-Tooth 1A. To diagnose peripheral nerve disorders, a careful history, physical examination and NCS are essential diagnostic tools, but the findings of this case suggest the importance of nerve imaging techniques in clinical situations.