C7 extension crosswise osteotomy: a novel osteotomy for correction of chin-on-chest deformity in a patient with ankylosing spondylitis

J Neurosurg Spine 34:424–429, 2021

Extension crosswise osteotomy at C7 (C7 ECO) was developed for the correction of forward gaze in patients with chinon- chest deformity due to ankylosing spondylitis.

A modification of cervicothoracic extension osteoclasis (C/T EO), C7 ECO replaces osteoclasis of the anterior column with a crosswise cut of the C7 vertebral body to eliminate the risks of unintended dislocation of the cervical spine. C7 ECO also eliminates the risks of C7 and T1 pedicle subtraction osteotomies (C/T PSOs), in which a posteriorly based wedge excision may lead to stretching injuries of the lower cervical roots and/or failure to achieve the exact angle of excision required for an optimal correction.

Furthermore, opening the osteotomy anteriorly, as in the authors’ method, instead of closing it posteriorly, as in PSO, eliminates the risks related to shortening of the posterior column, such as buckling of the dura, kinking of the spinal cord, and stretching of the lower cervical nerve roots.

Here, the authors report the use of C7 ECO for the surgical treatment of a 69-year-old man with severe compromise of his forward gaze due to chin-on-chest deformity in the course of ankylosing spondylitis. After uneventful correction surgery, the patient regained the ability to see objects, namely faces of people, at the level of his head while standing and to perform work tasks at a desk.

Cervical Spine Deformity—Part 3: Posterior Techniques, Clinical Outcome, and Complications

Neurosurgery 81:893–898, 2017

The goals of cervical deformity surgery include deformity correction, restoration of horizontal gaze, decompression of neural elements, spinal stabilization with a biomechanically sound construct, and meticulous arthrodesis technique to prevent pseudoarthrosis and minimizing surgical complications.

Many different surgical options exist, but selecting the correct approach that ensures the optimal clinical outcome can be challenging and often controversial. In this last part of the cervical deformity review series, various posterior deformity correction techniques are discussed in detail, along with an overview of surgical outcome and postoperative complications.

Cervical Spine Deformity—Part 2: Management Algorithm and Anterior Techniques

Neurosurgery 81:561–567, 2017

A sound operative plan based on solid understanding of the pathology and biomechanics is the most important part of cervical deformity correction.

Many different surgical options exist for operative management of cervical spine deformities. However, selecting the correct approach that ensures the optimal clinical outcome can be challenging and often controversial.

In Part 2 of this three-part review series, we discuss the pre-operative planning, management algorithm, and anterior surgical techniques for cervical deformity correction.

 

Cervical radiographic parameters in 1- and 2-level anterior cervical discectomy and fusion

cervical-radiographic-parameters-in-1-and-2-level-anterior-cervical-discectomy-and-fusion

J Neurosurg Spine 25:421–429, 2016

Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed spine procedures. It can be used to correct cervical kyphotic deformity, which is the most common cervical deformity, and is often performed using lordotic interbody devices. Worsening of the cervical sagittal parameters is associated with decreased health-related quality of life. The study hypothesis is that through the use of machined lordotic allografts in ACDF, segmental and overall cervical lordosis can be maintained or increased, which will have a positive impact on overall cervical sagittal alignment.

Methods: Seventy-four cases of 1-level ACDF (ACDF1) and 2-level ACDF (ACDF2) (40 ACDF1 and 34 ACDF2 procedures) were retrospectively reviewed. Upright neutral lateral radiographs were assessed preoperatively and at 6 weeks and 1 year postoperatively. The measured radiographic parameters included focal lordosis, disc height, C2–7 lordosis, C1–7 lordosis, T-1 slope, and C2–7 sagittal vertical axis. Correlation coefficients were calculated to determine the relationships between these radiographic measurements.

Results: The mean values were as follows: preoperative focal lordosis was 0.574°, disc height was 4.48 mm, C2–7 lordosis was 9.66°, C1–7 lordosis was 42.5°, cervical sagittal vertebral axis (SVA) was 26.9 mm, and the T-1 slope was 33.2°. Cervical segmental lordosis significantly increased by 6.31° at 6 weeks and 6.45° at 1 year. C2–7 lordosis significantly improved by 1 year with a mean improvement of 3.46°. There was a significant positive correlation between the improvement in segmental lordosis and overall cervical lordosis. Overall cervical lordosis was significantly negatively correlated with cervical SVA. Improved segmental lordosis was not correlated with cervical SVA in ACDF1 patients but was significantly negatively correlated in ACDF2 patients. There was also a significant positive correlation between the T-1 slope and cervical SVA.

Conclusions In the study population, the improvement of focal lordosis was significantly correlated with an improvement in overall lordosis (C1–7 and C2–7), and overall lordosis as measured by the C2–7 Cobb angle was significantly negatively correlated with cervical SVA. Using lordotic cervical allografts, we successfully created and maintained significant improvement in cervical segmental lordosis at the 6-week and 1-year time points with values of 6.31° and 6.45°, respectively. ACDF is able to achieve statistically significant improvement in C2–7 cervical lordosis by the 1-year followup, with a mean improvement of 3.46°. Increasing the number of levels operated on resulted in improved cervical sagittal parameters. This establishes a baseline for further examination into the ability of multilevel ACDF to achieve cervical deformity correction through the intervertebral correction of lordosis.

Algorithmic selection of cervical deformity surgery

An algorithmic strategy for selecting a surgical approach in cervical deformity correction

Neurosurg Focus 36 (5):E5, 2014

Adult degenerative cervical kyphosis is a debilitating disease that often requires complex surgical management. Young spine surgeons, residents, and fellows are often confused as to which surgical approach to choose due to lack of experience, absence of a systematic method of surgical management, and today’s plethora of information regarding surgical techniques. Although surgeons may be able to perform anterior, posterior, or combined (360°) approaches to the cervical spine, many struggle to rationally choose an appropriate approach for deformity correction.

The authors introduce an algorithm based on morphology and pathology of adult cervical kyphosis to help the surgeon select the appropriate approach when performing cervical deformity surgery.

Cervical deformities are categorized into 5 different prevalent morphological types encountered in clinical settings. A surgical approach tailored to each category/ type of deformity is then discussed, with a concrete case illustration provided for each.

Preoperative assessment of kyphosis, determination of the goal for surgery, and the complications associated with cervical deformity correction are also summarized. This article’s goal is to assist with understanding the big picture for surgical management in cervical spinal deformity.

Surgical treatment of cervical kyphosis

Eur Spine J. DOI 10.1007/s00586-010-1602-8.

Cervical kyphosis is an uncommon but potentially debilitating and challenging condition. We reviewed the etiology, presentation, clinical and radiological evaluation, and treatment of cervical kyphosis. Based on the current controversy as to the ideal mode of surgical management, we paid particular attention to the available surgical strategies. There are three approaches for cervical kyphosis: the anterior, posterior or combined procedures. The principal indication for the posterior strategy is a flexible kyphosis or kyphosis caused by ankylosing spondylitis. The main point of debate is between the choice of the anterior or the combined strategy. The two strategies were compared with regard to clinical outcome, correction of deformity, rate of fusion, complications, revision surgery, and mortality. The combined strategy appears to result in a greater degree of correction than the anterior-alone strategy, and it is more likely to improve the cervical alignment to achieve a lordosis. However, the procedure carries a higher rate of postoperative neurological deterioration, complications, revision surgery, and mortality. Although the anterioralone strategy achieves a smaller reduction of cervical kyphosis, it has a lower rate of postoperative neurological deterioration, complications, revision surgery, and mortality. We recommend that the surgical treatment of cervical kyphosis should be planned on an individual basis. A multicenter, prospective, randomized controlled study would be necessary to determine the ideal mode of treatment for complex cervical kyphosis

Surgical treatment of cervical kyphosis

Eur Spine J. DOI 10.1007/s00586-010-1602-8

Cervical kyphosis is an uncommon but potentially debilitating and challenging condition.

We reviewed the etiology, presentation, clinical and radiological evaluation, and treatment of cervical kyphosis. Based on the current controversy as to the ideal mode of surgical management, we paid particular attention to the available surgical strategies.

There are three approaches for cervical kyphosis: the anterior, posterior or combined procedures. The principal indication for the posterior strategy is a flexible kyphosis or kyphosis caused by ankylosing spondylitis.

The main point of debate is between the choice of the anterior or the combined strategy. The two strategies were compared with regard to clinical outcome, correction of deformity, rate of fusion, complications, revision surgery, and mortality. The combined strategy appears to result in a greater degree of correction than the anterior-alone strategy, and it is more likely to improve the cervical alignment to achieve a lordosis. However, the procedure carries a higher rate of postoperative neurological deterioration, complications, revision surgery, and mortality. Although the anterior alone strategy achieves a smaller reduction of cervical kyphosis, it has a lower rate of postoperative neurological deterioration, complications, revision surgery, and mortality.

We recommend that the surgical treatment of cervical kyphosis should be planned on an individual basis.

A multicenter, prospective, randomized controlled study would be necessary to determine the ideal mode of treatment for complex cervical kyphosis.