A controlled anterior sequential interbody dilation technique for correction of cervical kyphosis

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>Cervical kyphosis can lead to spinal instability, spinal cord injury, and disability. The correction of cervical kyphosis is technically challenging, especially in severe cases. The authors describe the anterior sequential interbody dilation technique for the treatment of cervical kyphosis and evaluate perioperative outcomes, degree of correction, and long-term follow-up outcomes associated with the technique.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>In the period from 2006 to 2011, a consecutive cohort of adults with cervical kyphosis (Cobb angles ≥ 0°) underwent sequential interbody dilation, a technique entailing incrementally increased interbody distraction with the sequential placement of larger spacers (at least 1 mm) in the discectomy and/or corpectomy spaces. The authors retrospectively reviewed these patients, and primary outcomes of interest included kyphosis correction, blood loss, hospital stay, complications, Nurick grade, pain, reoperation, and pseudarthrosis. A subgroup analysis among patients with preoperative kyphosis of 0°–9° (mild), 10°–19° (moderate), and ≥ 20° (severe) was performed.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>One hundred patients were included in the study: 74 with mild preoperative cervical kyphosis, 19 with moderate, and 7 with severe. The mean patient age was 53.1 years, and 54.0% of the patients were male. Mean estimated blood loss was 305.6 ml, and the mean length of hospital stay was 5.2 days. The overall complication rate was 9.0%, and there were no deaths. Sixteen percent of patients underwent supplemental posterior fusion. There was significant correction in cervical alignment (p &lt; 0.001), and the mean overall kyphosis correction was 12.4°. Patients with severe preoperative kyphosis gained a correction of 24.7°, those with moderate kyphosis gained 17.8°, and those with mild kyphosis gained 10.1°. A mean correction of 32.0° was obtained if 5 levels were addressed. The mean follow-up was 26.8 months. The reoperation rate was 4.7%. At follow-up, there was significant improvement in visual analog scale neck pain (p = 0.020) and Nurick grade (p = 0.037). The pseudarthrosis rate was 6.3%.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>Sequential interbody dilation is a feasible and effective method of correcting cervical kyphosis. Complications and reoperation rates are low. Similar benefits are seen among all severities of kyphosis, and greater correction can be achieved in more severe cases.</jats:p></jats:sec>

Altered pharyngeal structure and dynamics among patients with cervical kyphosis

“…Therefore, the difference between people with excessive kyphosis compared to those with normal curvature in the community is likely greater than we were able to appreciate in this investigation. Similarly, we defined abnormal cervical kyphosis as 2 SDs outside of age‐adjusted normal values, whereas other references consider all cervical kyphosis angles greater than 0° to be abnormal but accounts for gradation of severity . According to this alternative definition, our patient cohort has moderately severe kyphosis on average.…”

“…The primary indications for surgical intervention in cervical kyphosis are related to pain from radiculopathy or myelopathy, instability, and impaired horizontal gaze. 17 Excessive spinal curvature leads to spinal cord injury and peripheral neuropathy because of extrinsic spinal cord compression or nerve traction, whereas instability is a result of altered muscle and ligament forces. An essential function of the larynx is to navigate food and liquid through the oropharynx, which is a region of the head and neck with shared airway and digestive tract functions.…”

“…Similarly, we defined abnormal cervical kyphosis as 2 SDs outside of age-adjusted normal values, 4 whereas other references consider all cervical kyphosis angles greater than 08 to be abnormal but accounts for gradation of severity. 17 According to this alternative definition, our patient cohort has moderately severe kyphosis on average. Finally, the role of surgery in our kyphosis and control populations deserves mention.…”

Anterior Reconstruction Techniques for Cervical Spine Deformity

“…23 However, when applied over multiple levels there is a cumulative effect on realignment, with a mean global correction of 32.0° if 5 levels are addressed -or again approximately 6.4° per level. 24 Segmental lordosis may be obtained through several techniques. If the bone quality is sufficient, then use of Caspar pins placed convergently will create lordosis when distraction is applied.…”

“…This may be avoided with the use of intervertebral body spreaders along with sequentially taller spacers for controlled dilation of the disc space. 24,25 Thus, multilevel anterior cervical discectomy and fusion can be an effective tool in restoring cervical lordosis.…”