T-1 pedicle subtraction osteotomy for the treatment of rigid cervical kyphotic deformity: report of 4 cases

Clinical and radiologic outcomes of posterior column extension, pedicle subtraction, and vertebral column resection osteotomies in adult chin on chest deformity: A systematic review

Background

Chin-on-chest deformity is a rare and severely disabling condition characterized by kyphotic deformity in the cervicothoracic spine. To treat this deformity, various osteotomy techniques were described.

Methods

A comprehensive literature search of biomedical databases including MEDLINE (via PubMed), Scopus (via Elsevier), Embase (via Elsevier), and Cochrane Library in English from 1/1/1990 to 3/31/2022 was conducted using a combination of text and Medical Subject Headings (MeSH).

Results

The final analysis included 16 studies. All the studies were assigned a level of evidence of four. Except for two articles, all of the articles were non-comparative studies. A total of 288 patients were included in this review. Of the 288 patients, 107 underwent posterior column extension osteotomy (PCEO), 108 underwent pedicle subtraction osteotomy (PSO), and 33 underwent vertebral column resection osteotomy (VCRO). The most common osteotomy level in fifteen of the studies was C7/T1. The studies included in this review described several techniques for cervical sagittal balance correction. The range of preoperative and postoperative visual analogue scale (VAS) scores was 5.5-8.6 to 1.7-4.91, respectively. The range of preoperative and postoperative neck disability index (NDI) was 34.2-65.4 to 22.1-51.3, respectively. The most common complications were upper extremity paresthesia and hand numbness through the C8 dermatome distribution.

Conclusions

Corrective osteotomies provide satisfactory results in patients with chin-on-chest deformity; however, the quality of the included studies limits the evidence.

Utility of intraoperative neuromonitoring and outcomes of neurological complication in lower cervical and upper thoracic posterior-based three-column osteotomies for cervical deformity

OBJECTIVE

For severe and rigid adult cervical deformity, posterior-based three-column osteotomies (3COs) are warranted, but neurological complications are relatively high with such procedures. The performance measures of intraoperative neuromonitoring (IONM) during cervicothoracic 3CO have yet to be studied, and there remains a paucity of literature regarding the topic. Therefore, the authors of this study examined the performance of IONM in predicting new neurological weakness following lower cervical and upper thoracic 3CO. In addition, they report the 6-month, 1-year, and 2-year outcomes of patients who experienced new postoperative weakness.

METHODS

The authors performed a retrospective review of a single surgeon's experience from 2011 to 2018 with all patients who had undergone posterior-based 3CO in the lower cervical (C7) or upper thoracic (T1-4) spine. Medical and neuromonitoring records were independently reviewed.

RESULTS

A total of 56 patients were included in the analysis, 38 of whom had undergone pedicle subtraction osteotomy and 18 of whom had undergone vertebral column resection. The mean age was 61.6 years, and 41.1% of the patients were male. Among the study cohort, 66.1% were myelopathic and 33.9% had preoperative weakness. Mean blood loss was 1565.0 ml, and length of surgery was 315.9 minutes. Preoperative and postoperative measures assessed were cervical sagittal vertical axis (6.5 and 3.8 cm, respectively; p < 0.001), cervical lordosis (2.3° and -6.7°, p = 0.042), and T1 slope (48.6° and 35.8°, p < 0.001). The complication rate was 49.0%, and the new neurological deficit rate was 17.9%. When stratifying by osteotomy level, there were significantly higher rates of neurological deficits at C7 and T1: C7 (37.5%), T1 (44.4%), T2 (16.7%), T3 (14.3%), and T4 (0.0%; p = 0.042). Most new neurological weakness was the nerve root pattern rather than the spinal cord pattern. Overall, there were 16 IONM changes at any threshold: 14 at 50%, 8 at 75%, and 13 if only counting patients who did not return to baseline (RTB). Performance measures for the various thresholds were accuracy (73.2% to 77.8%), positive predictive value (25.0% to 46.2%), negative predictive value (81.3% to 88.1%), sensitivity (18.2% to 54.5%), and specificity (77.8% to 86.7%). Sensitivity to detect a spinal cord pattern of weakness was 100% and 28.6% for a nerve root pattern of weakness. In patients with a new postoperative deficit, 22.2% were unchanged, 44.4% improved, and 33.3% had a RTB at the 2-year follow-up.

CONCLUSIONS

Complication rates are high following posterior 3CO for cervical deformity. 3CO at C7 and T1 has the highest rates of neurological deficit. Current IONM modalities have modest performance in predicting postoperative deficits, especially for nerve root neuropraxia. A large prospective multicenter study is warranted.

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

Extension crosswise osteotomy at C7 (C7 ECO) was developed for the correction of forward gaze in patients with chin-on-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.

Severe, rigid cervical kyphotic deformity associated with SAPHO syndrome successfully treated with three-stage correction surgery combined with C7 vertebral column resection: a technical case report

STUDY DESIGN

Case report.

OBJECTIVES

To describe the first reported use of corrective surgery combined with C7 vertebral column resection (VCR) to treat an extremely rare case of severe, rigid cervical kyphotic deformity associated with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.

BACKGROUND DATA

Spinal lesions reportedly occur in 32-45% in SAPHO syndrome. However, bone and joint lesions are usually repaired such that severe joint destruction is rare. Therefore, there have been few reported cases of surgical treatment for spinal lesions.

METHODS

A 22-year-old woman had been diagnosed with cervical kyphotic deformity associated with SAPHO syndrome. She had difficulty looking upward. On radiography, the C4-C7 vertebral bodies were fused and exhibited severe rigid kyphotic deformity. Right convex scoliosis with a Cobb angle of 22° was apparent at C5-T2, and the C2-C7 angle of kyphosis was 75°. Corrective three-stage surgery was carried out from the anterior, posterior, and anterior, with C7 VCR.

RESULTS

The C2-T1 angle improved to 21° and the patient was capable of looking up. At present, 2 years postoperatively, complete bony fusion has been achieved. Her cervical spine function and quality of life were markedly improved.

CONCLUSION

Only a very limited number of patients have a deformity sufficiently severe that VCR of cervical vertebra is required, but as this is the technique that provides the greatest multiplanar alignment correction, its choice in the present case was appropriate.

LEVEL OF EVIDENCE

IV.

The Effect of T1-Slope in Spinal Parameters After Cervical Disc Arthroplasty

BACKGROUND

Although patients with cervical kyphosis are not ideal candidates for cervical disc arthroplasty (CDA), there is a paucity of data on patients with a straight or slightly lordotic neck.

OBJECTIVE

To correlate cervical lordosis, T1-slope, and clinical outcomes of CDA.

METHODS

The study retrospectively analyzed 95 patients who underwent 1-level CDA and had 2-yr follow-up. They were divided into a high T1-slope (≥28°) group (HTSG, n = 45) and a low T1-slope (<28°) group (LTSG, n = 50). Cervical spinal alignment parameters, including T1-slope, cervical lordosis (C2-7 Cobb angle), and segmental mobility (range of motion [ROM]) at the indexed level, were compared. The clinical outcomes were also assessed.

RESULTS

The mean T1-slope was 28.1 ± 7.0°. After CDA, the pre- and postoperative segmental motility remained similar and cervical lordosis was preserved. All the clinical outcomes improved after CDA. The HTSG were similar to the LTSG in age, sex, segmental mobility, and clinical outcomes. However, the HTSG had higher cervical lordosis than the LTSG. Furthermore, the LTSG had increased cervical lordosis (ΔC2-7 Cobb angle), whereas the HTSG had decreased lordosis after CDA. Patients of the LTSG, who had more improvement in cervical lordosis, had a trend toward increasing segmental mobility at the index level (ΔROM) than the HTSG.

CONCLUSION

In this series, T1-slope correlated well with global cervical lordosis but did not affect the segmental mobility. After CDA, the changes in cervical lordosis correlated with changes in segmental mobility. Therefore, segmental lordosis should be cautiously preserved during CDA as it could determine the mobility of the disc.

Cervical Deformity Arising From Upper Thoracic Malalignment

This study aims to describe the surgical management of cervical deformity arising from outside the cervical spine because of upper thoracic malalignment, using pedicle subtraction osteotomy (PSO). Cervical spine deformity is a complex topic and it can be generally divided into 2 categories, the first category is when the primary deformity is inside the cervical spine and the treatment will focus on the cervical spine itself, whereas the second category is when the primary deformity is outside the cervical spine usually in the adjacent upper thoracic area, the cervical deformity is a compensation for the adjacent malalignment, and thus in this situation, the management will occur in the upper thoracic area. Description of a single surgeon’s technique for performing PSO to treat rigid upper thoracic deformity. PSO in the upper thoracic spine is a safe and effective procedure and can result in satisfying clinical and radiological outcome with indirect correction of the compensatory cervical deformity. Cervical deformity arising from upper thoracic malalignment should be dealt with by treating the problem at its origin outside the cervical spine by performing a PSO in the upper thoracic spine.

Comparison of perioperative complications following posterior column osteotomy versus posterior-based 3-column osteotomy for correction of rigid cervicothoracic deformity: a single-surgeon series of 95 consecutive cases

OBJECTIVE

The correction of severe cervicothoracic sagittal deformities can be very challenging and can be associated with significant morbidity. Often, soft-tissue releases and osteotomies are warranted to achieve the desired correction. There is a paucity of studies that examine the difference in morbidity and complication profiles for Smith-Petersen osteotomy (SPO) versus 3-column osteotomy (3CO) for cervical deformity correction.

METHODS

A retrospective comparison of complication profiles between posterior-based SPO (Ames grade 2 SPO) and 3CO (Ames grade 5 opening wedge osteotomy and Ames grade 6 closing wedge osteotomy) was performed by examining a single-surgeon experience from 2011 to 2018. Patients of interest were individuals who had a cervical sagittal vertical axis (cSVA) > 4 cm and/or cervical kyphosis > 20° and who underwent corrective surgery for cervical deformity. Multivariate analysis was utilized.

RESULTS

A total of 95 patients were included: 49 who underwent 3CO and 46 who underwent SPO. Twelve of the SPO patients underwent an anterior release procedure. The patients' mean age was 63.2 years, and 60.0% of the patients were female. All preoperative radiographic parameters showed significant correction postoperatively: cSVA (6.2 cm vs 4.5 cm [preoperative vs postoperative values], p < 0.001), cervical lordosis (6.8° [kyphosis] vs -7.5°, p < 0.001), and T1 slope (40.9° and 35.2°, p = 0.026). The overall complication rate was 37.9%, and postoperative neurological deficits were seen in 16.8% of patients. The surgical and medical complication rates were 17.9% and 23.2%, respectively. Overall, complication rates were higher in patients who underwent 3CO compared to those who underwent SPO, but this was not statistically significant (total complication rate 42.9% vs 32.6%, p = 0.304; surgical complication rate 18.4% vs 10.9%, p = 0.303; and new neurological deficit rate 20.4% vs 13.0%, p = 0.338). Medical complication rates were similar between the two groups (22.4% [3CO] vs 23.9% [SPO], p = 0.866). Independent risk factors for surgical complications included male sex (OR 10.88, p = 0.014), cSVA > 8 cm (OR 10.36, p = 0.037), and kyphosis > 20° (OR 9.48, p = 0.005). Combined anterior-posterior surgery was independently associated with higher odds of medical complications (OR 10.30, p = 0.011), and preoperative kyphosis > 20° was an independent risk factor for neurological deficits (OR 2.08, p = 0.011).

CONCLUSIONS

There was no significant difference in complication rates between 3CO and SPO for cervicothoracic deformity correction, but absolute surgical and neurological complication rates for 3CO were higher. A preoperative cSVA > 8 cm was a risk factor for surgical complications, and kyphosis > 20° was a risk factor for both surgical and neurological complications. Additional studies are warranted on this topic.

Transdiscal C7 Pedicle Subtraction Osteotomy With a Strut Graft and the Correction of Sagittal and Coronal Imbalance of the Cervical Spine

BACKGROUND

Cervical spine deformity negatively affects patients' quality of life. Pedicle subtraction osteotomy (PSO) has reported to correct cervical deformity but it is challenging and carries a significant risk of morbidity.

OBJECTIVE

To report transdiscal C7 PSO with a strut graft for the correction of sagittal and coronal imbalance in patients with fixed cervical deformity.

METHODS

After standard exposure, the spine was instrumented from C2 to T3. T1 subtotal laminectomy, and C6 to C7 total laminectomies were necessary for C7 PSO. Osteotomy was initiated with removal of C6-7 and C7-T1 facet joints to isolate C7 pedicles and identify bilateral C7/C8 roots. Bilateral C7 pediculectomies and transdiscal PSO were performed. A rectangular strut allograft was then inserted into the PSO site. The location of the strut graft was used as a fulcrum of sagittal and coronal correction. The head fixator was released and the head was extended under intraoperative neuromonitoring, and then detailed sagittal and coronal balances were controlled by compressing or distracting between the pedicle screws above and below the osteotomy.

RESULTS

This technique was applied in 2 patients with fixed subaxial cervical deformities. Transdiscal PSO could add more amount of correction and provide the additional fusion surface. The strut graft prevented sagittal translation, foraminal narrowing, and excessive focal cord kinking during PSO. Both patients showed radiologic and clinical improvements after surgery, and no neurovascular complication occurred after the surgery.

CONCLUSION

Transdiscal C7 PSO with a strut graft placement provided a safe way of correcting sagittal and coronal imbalance simultaneously and reduced neurological complication by preventing sagittal translation, foraminal narrowing and spinal cord kinking.

The case for T2 pedicle subtraction osteotomy in the surgical treatment of rigid cervicothoracic deformity

OBJECTIVE

Rigid cervicothoracic kyphotic deformity (CTKD) remains a difficult pathology to treat, especially in the setting of prior cervical instrumentation and fusion. CTKD may result in chronic neck pain, difficulty maintaining horizontal gaze, and myelopathy. Prior studies have advocated for the use of C7 or T1 pedicle subtraction osteotomies (PSOs). However, these surgeries are fraught with danger and, most significantly, place the C7, C8, and/or T1 nerve roots at risk.

METHODS

The authors retrospectively reviewed their experience with performing T2 PSO for the correction of rigid CTKD. Demographics collected included age, sex, details of prior cervical surgery, and coexisting conditions. Perioperative variables included levels decompressed, levels instrumented, estimated blood loss, length of surgery, length of stay, complications from surgery, and length of follow-up. Radiographic measurements included C2-7 sagittal vertical axis (SVA) correction, and changes in the cervicothoracic Cobb angle, lumbar lordosis, and C2-S1 SVA.

RESULTS

Four male patients were identified (age range 55-72 years). Three patients had undergone prior posterior cervical laminectomy and instrumented fusion and developed postsurgical kyphosis. All patients underwent T2 PSO: 2 patients received instrumentation at C2-T4, and 2 patients received instrumentation at C2-T5. The median C2-7 SVA correction was 3.85 cm (range 2.9-5.3 cm). The sagittal Cobb angle correction ranged from 27.8° to 37.6°. Notably, there were no neurological complications.

CONCLUSIONS

T2 PSO is a powerful correction technique for the treatment of rigid CTKD. Compared with C7 or T1 PSO, there is decreased risk of injury to intrinsic hand muscle innervators, and there is virtually no risk of vertebral artery injury. Laminectomy may also be safer, as there is less (or no) scar tissue from prior surgeries. Correction at this distal level may allow for a greater sagittal correction. The authors are optimistic that these findings will be corroborated in larger cohorts examining this challenging clinical entity.

Staged cervical osteotomy:a new strategy for correcting ankylosing spondylitis thoracolumbar kyphotic deformity with fused cervical spine

Background

In patients with cervical ankylosis, the chin-brow vertical angle (CBVA) should be taken into consideration. Usually, the correction of sagittal balance is sacrificed to ensure the patient has a horizontal visual field. To our knowledge, a staged osteotomy strategy for ankylosing spondylitis kyphotic deformity with an ankylosed cervical spine has not been reported before. The aim of this study was to describe a new surgical strategy with emphasis on sagittal balance and gaze angle in correction of kyphotic deformity with a rigid cervical spine in ankylosing spondylitis thoracolumbar kyphotic deformity.

Methods

A 36-year-old man has severe thoracolumbar kyphosis accompanied with cervical hyperlordosis caused by ankylosing spondylitis. A two-stage surgery planning was managed. For the first stage, an interrupted two-level osteotomy was performed at the thoracolumbar area. After surgery, sagittal imbalance was corrected but the CBVA was − 21.7°. Cervical osteotomy was performed for the second stage. A flexion osteotomy was performed at C7, using anterior-posterior-anterior approaches.

Results

Both sagittal imbalance and gaze angle of the patient were improved markedly. The osteotomy sites were documented fused. Complications were not observed during and after operation.

Conclusions

The aim of osteotomy for ankylosing spondylitis is to reestablish sagittal balance and improve forward gaze and the visual field. A staged cervical osteotomy is an alternative to reduce cervical lordosis to obtain a normal gaze angle. An anterior-posterior-anterior approach is recommended.