Cervicothoracic junction kyphosis: surgical reconstruction with pedicle subtraction osteotomy and Smith-Petersen osteotomy

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.

Three-Column Osteotomy for the Treatment of Rigid Cervical Deformity

Adult cervical deformity (ACD) has been shown to have a substantial impact on quality of life and overall health, with moderate to severe deformities resulting in significant disability and dysfunction. Fortunately, surgical management and correction of cervical sagittal imbalance can offer significant benefits and improvement in pain and disability. ACD is a heterogenous disease and specific surgical correction strategies should reflect deformity type (driver of deformity) and patient-related factors. Spinal rigidity is one of the most important considerations as soft tissue releases and osteotomies play a crucial role in cervical deformity correction. For ankylosed, fixed, and severe deformity, 3-column osteotomy (3CO) is often warranted. A 3CO can be done through combined anteriorposterior (vertebral body resection) and posterior-only approaches (open or closed wedge pedicle subtraction osteotomies [PSOs]). This article reviews the literature for currently published studies that report results on the use of 3CO for ACD, with a special concentration on posterior based 3CO (open and closed wedge PSO). More specifically, this review discusses the indications, radiographic corrective ability, and associated complications.

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.

Modified C7 pedicle subtraction osteotomy for the correction of cervicothoracic kyphosis

BACKGROUND

Osteotomies in the cervical spine are technically challenging. The purpose of this study was to evaluate the feasibility of the modified pedicle subtraction osteotomy (PSO) technique at C7 to be used for the treatment of cervicothoracic kyphosis secondary to ankylosing spondylitis.

METHODS

A total of 120 cervical spine computed tomography (CT) scans (of 82 male and 38 female patients) were evaluated. The scans were taken parallel to the middle sagittal plane and the sagittal plane intersecting the pedicles. Simulated osteotomy was performed by setting the apex of the wedge osteotomy at different points, and morphologic measurements were obtained. Seven patients with cervicothoracic kyphosis who underwent a modified PSO at C7 between May 2009 and June 2015 were retrospectively evaluated. The mean follow up was 32.9 months (range 21-54 months). Preoperative and postoperative chin-brow vertical angle (CBVA), sagittal vertical axis (SVA) and sagittal Cobb angle of the cervical region were reviewed. The outcomes were analyzed through various measures, which included the 36-Item Short Form Health Survey (SF-36) and a visual analog scale for neck pain.

RESULTS

In this morphometric study, a modified PSO was performed on 87 patients (59 male and 28 female) with a reasonable ratio of 72.5%. In the case series, radiographic parameters and health-related quality-of-life measures were found to show significant postoperative improvement in all patients. No major complications occurred, and no implant failures were noted until the latest follow up.

CONCLUSIONS

The modified PSO is a safe and valid alternative to the classic PSO, allowing for excellent correction of cervical kyphosis and improvement in health-related quality-of-life measures.

Prospective Multicenter Assessment of All-Cause Mortality Following Surgery for Adult Cervical Deformity

BACKGROUND

Surgical treatments for adult cervical spinal deformity (ACSD) are often complex and have high complication rates.

OBJECTIVE

To assess all-cause mortality following ACSD surgery.

METHODS

ACSD patients presenting for surgical treatment were identified from a prospectively collected multicenter database. Clinical and surgical parameters and all-cause mortality were assessed.

RESULTS

Of 123 ACSD patients, 120 (98%) had complete baseline data (mean age, 60.6 yr). The mean number of comorbidities per patient was 1.80, and 80% had at least 1 comorbidity. Surgical approaches included anterior only (15.8%), posterior only (50.0%), and combined anterior/posterior (34.2%). The mean number of vertebral levels fused was 8.0 (standard deviation [SD] = 4.5), and 23.3% had a 3-column osteotomy. Death was reported for 11 (9.2%) patients at a mean of 1.1 yr (SD = 0.76 yr; range = 7 d to 2 yr). Mean follow-up for living patients was 1.2 yr (SD = 0.64 yr). Causes of death included myocardial infarction (n = 2), pneumonia/cardiopulmonary failure (n = 2), sepsis (n = 1), obstructive sleep apnea/narcotics (n = 1), subsequently diagnosed amyotrophic lateral sclerosis (n = 1), burn injury related to home supplemental oxygen (n = 1), and unknown (n = 3). Deceased patients did not significantly differ from alive patients based on demographic, clinical, or surgical parameters assessed, except for a higher major complication rate (excluding mortality; 63.6% vs 22.0%, P = .006).

CONCLUSION

All-cause mortality at a mean of 1.2 yr following surgery for ACSD was 9.2% in this prospective multicenter series. Causes of death were reflective of the overall high level of comorbidities. These findings may prove useful for treatment decision making and patient counseling in the context of the substantial impact of ACSD.

Outcomes of 360° Osteotomy in the Cervicothoracic Spine (C7-T1) for Congenital Cervicothoracic Kyphoscoliosis in Children

BACKGROUND

There have been many reports on the treatment of congenital kyphoscoliosis. However, congenital deformities in the cervicothoracic spine (C7-T1) have not been well described because of the rarity of these conditions.

METHODS

The medical records and imaging studies of 25 children who were treated with 360° osteotomy for congenital deformities in the cervicothoracic spine (C7-T1) at a mean age of 11.4 years were reviewed.

RESULTS

All 25 children presented with torticollis; 4 presented with neck pain; 10, with facial asymmetry; and 3, with preoperative neurological deficits. Twenty-three patients had congenital deformities in other regions of the spine. Six patients had a total of 8 intraspinal deformities. On average, the cervicothoracic curve was corrected from 53° preoperatively to 14° at the latest follow-up, the segmental kyphosis was corrected from 25° to 12°, and the head tilt improved from 25° to 5°. Nineteen patients had a total of 28 complications, including 1 transient cord injury together with a permanent C8 nerve root injury, 11 transient nerve root injuries, 1 transient Horner syndrome, 9 cases of decompensation of a compensatory curve, 2 implant failures, 2 cases of hemothorax, 1 dural tear, and 1 case of delayed wound-healing.

CONCLUSIONS

Most congenital cervicothoracic deformities are fixed, and early surgical intervention may be needed. A 360° osteotomy is indicated for this type of rigid deformity and may provide satisfactory correction. However, 360° osteotomy in the cervicothoracic spine (C7-T1) is technically demanding with a higher risk of nerve root injuries, although most injuries tend to be transient. If the compensatory thoracic curve is severe and rigid, 1-stage or staged surgery in this region may be required.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Adult cervical deformity: radiographic and osteotomy classifications

Cervical spine deformity represents a broad spectrum of pathologies that are both complex in etiology and debilitating towards quality of life for patients. Despite advances in the understanding of drivers and outcomes of cervical spine deformity, only one classification system and one system of nomenclature for osteotomy techniques currently exist. Moreover, there is a lack of standardization regarding the indications for each technique. This article reviews the adult cervical deformity (ACD) and current classification and nomenclature for osteotomy techniques, highlighting the need for further work to develop a unified approach for each case and improve communication amongst the spine community with respect to ACD.

Characteristics of deformity surgery in patients with severe and rigid cervical kyphosis (CK): results of the CSRS-Europe multi-centre study project

INTRODUCTION AND PURPOSE

Little information exists on surgical characteristics, complications and outcomes with corrective surgery for rigid cervical kyphosis (CK). To collate the experience of international experts, the CSRS-Europe initiated an international multi-centre retrospective study.

METHODS

Included were patients at all ages with rigid CK. Surgical and patient specific characteristics, complications and outcomes were studied. Radiographic assessment included global and regional sagittal parameters. Cervical sagittal balance was stratified according to the CSRS-Europe classification of sagittal cervical balance (types A-D).

RESULTS

Eighty-eight patients with average age of 58 years were included. CK etiology was ankylosing spondlitis (n = 34), iatrogenic (n = 25), degenerative (n = 9), syndromatic (n = 6), neuromuscular (n = 4), traumatic (n = 5), and RA (n = 5). Blood loss averaged 957 ml and the osteotomy grade 4.CK-correction and blood loss increased with osteotomy grade (r = 0.4/0.6, p < .01). Patients with different preop sagittal balance types had different approaches, preop deformity parameters and postop alignment changes (e.g. C7-slope, C2-7 SVA, translation). Correction of the regional kyphosis angle (RKA) was average 34° (p < .01). CK-correction was increased in patients with osteoporosis and osteoporotic vertebrae (POV, p = .006). 22% of patients experienced a major long-term complication and 14% needed revision surgery. Patients with complications had larger preop RKA (p = .01), RKA-change (p = .005), and postop increase in distal junctional kyphosis angle (p = .02). The POV-Group more often experienced postop complications (p < .0001) and revision surgery (p = .02). Patients with revision surgery had a larger RKA-change (p = .003) and postop translation (p = .04). 21% of patients had a postop segmental motor deficit and the risk was elevated in the POV-Group (p = .001).

CONCLUSIONS

Preop patient specific, radiographic and surgical variables had a significant bearing on alignment changes, outcomes and complication occurrence in the treatment of rigid CK.

Computer-Assisted Navigation for Real Time Planning of Pedicle Subtraction Osteotomy in Cervico-Thoracic Deformity Correction

BACKGROUND

Pedicle subtraction osteotomy (PSO) at the cervicothoracic junction (CTJ) is a powerful technique to correct severe kyphosis and sagittal malalignment. Reported techniques have demonstrated the safety and efficacy of the PSO, however limited visualization of surrounding tissues increases the potential for complications with this advanced technique.

OBJECTIVE

To describe the application of computed tomographic (CT)-based image guidance to the planning and execution of PSO at the CTJ.

METHODS

Intraoperative registration and verification of anatomic landmarks are performed with the intraoperative O-arm CT across the CTJ. With the navigation probe, the targeted pedicle is identified and the intended trajectories are rehearsed and saved on the navigational computer. As the PSO is performed, the navigation probe is used to check the depth, accuracy, and trajectory through each side. The extent of soft tissue dissection around the lateral aspect of the vertebral body through which the PSO is performed is also verified in real time. This technique was performed in 12 consecutive patients from 2013-2016. An IRB approved, retrospective analysis was performed from a prospective spinal deformity outcomes database. Patient consent is not required for publication as this report does not describe a specific case but rather a surgical technique used in practice.

RESULTS

There were no vascular, esophageal, or soft tissue injuries in 12 consecutive patients. There were no cases of paralysis. Two patients developed hand weakness days after surgery. Intraoperative O-arm CT performed after closure of the osteotomy confirmed the accuracy of the osteotomy planning with no breach of the anterior cortical wall of the osteotomized vertebral body.

CONCLUSION

CT-guided navigation allows for 3-dimensional visualization of the CTJ and minimizes complications associated with inadequate surgical visualization of vascular and deep organ structures.

Analysis of Successful Versus Failed Radiographic Outcomes After Cervical Deformity Surgery

STUDY DESIGN

Prospective multicenter cohort study with consecutive enrollment.

OBJECTIVE

To evaluate preoperative alignment and surgical factors associated with suboptimal early postoperative radiographic outcomes after surgery for cervical deformity.

SUMMARY OF BACKGROUND DATA

Recent studies have demonstrated correlation between cervical sagittal alignment and patient-reported outcomes. Few studies have explored cervical deformity correction prospectively, and the factors that result in successful versus failed cervical alignment corrections remain unclear.

METHODS

Patients with adult cervical deformity (ACD) included with either cervical kyphosis more than 10°, C2-C7 sagittal vertical axis (cSVA) of more than 4 cm, or chin-brow vertical angle of more than 25°. Patients were categorized into failed outcomes group if cSVA of more than 4 cm or T1 slope and cervical lordosis (TS-CL) of more than 20° at 6 months postoperatively.

RESULTS

A total of 71 patients with ACD (mean age 62 yr, 56% women, 41% revisions) were included. Fourty-five had primary cervical deformities and 26 at the cervico-thoracic junction. Thirty-three (46.4%) had failed radiographic outcomes by cSVA and 46 (64.7%) by TS-CL. Failure to restore cSVA was associated with worse preoperative C2 pelvic tilt angle (CPT: 64.4° vs. 47.8°, P = 0.01), worse postoperative C2 slope (35.0° vs. 23.8°, P = 0.004), TS-CL (35.2° vs. 24.9°, P = 0.01), CPT (47.9° vs. 28.2°, P < 0.001), "+" Schwab modifiers (P = 0.007), revision surgery (P = 0.05), and failure to address the secondary, thoracolumbar driver of the deformity (P = 0.02). Failure to correct TS-CL was associated with worse preoperative cervical kyphosis (10.4° vs. -2.1°, P = 0.03), CPT (52.6° vs. 39.1°, P = 0.04), worse postoperative C2 slope (30.2° vs. 13.3°, P < 0.001), cervical lordosis (-3.6° vs. -15.1°, P = 0.01), and CPT (37.7° vs. 24.0°, P < 0.001). Multivariate analysis revealed postoperative distal junctional kyphosis associated with suboptimal outcomes by cSVA (odds ratio 0.06, confidence interval 0.01-0.4, P = 0.004) and TS-CL (odds ratio 0.15, confidence interval 0.02-0.97, P = 0.05).

CONCLUSION

Factors associated with failure to correct the cSVA included revision surgery, worse preoperative CPT, and concurrent thoracolumbar deformity. Failure to correct the TS-CL mismatch was associated with worse preoperative cervical kyphosis and CPT. Occurrence of early postoperative distal junctional kyphosis significantly affects postoperative radiographic outcomes.

LEVEL OF EVIDENCE

3.

Cervicothoracic Lordosis Can Influence Outcome After Posterior Cervical Spine Surgery

Background:

Previous studies on the correlation between cervical sagittal balance with improvement in quality of life showed significant results only for parameters of the anterior translation of the cervical spine (such as C2-C7 SVA).

Objective:

We test whether a new parameter, cervicothoracic lordosis, can predict clinical success in this type of surgery.

Methods:

The focused group involved patients who underwent surgical treatment of cervical degenerative disk disease by the posterior approach, due to myelopathy, radiculopathy or a combination of both. Neurologic deficit was measured before and after surgery with the Nurick Scale, postoperative quality of life, physical and mental components of SF-36 and NDI. Cervicothoracic lordosis and various sagittal balance parameters were also measured. Cervicothoracic lordosis was defined as the angle between: a) the line between the centroid of C2 and the centroid of C7; b) the line between the centroid of C7 and the centroid of T6. Correlations between postoperative quality of life and sagittal parameters were calculated.

Results:

Twenty-nine patients between 27 and 78 years old were evaluated. Surgery types were simple decompression (laminectomy or laminoforaminotomy) (3 patients), laminoplasty (4 patients) and laminectomy with fusion in 22 patients. Significant correlations were found for C2-C7 SVA and cervicothoracic lordosis. C2-C7 SVA correlated negatively with MCS (r=-0.445, p=0.026) and PCS (r=-0.405, p=0.045). Cervicothoracic lordosis correlated positively with MCS (r=0.554, p= 0.004) and PCS (r=0.462, p=0.020) and negatively with NDI (r=-0.416, p=0.031).

Conclusion:

The parameter cervicothoracic lordosis correlates with improvement of quality life after surgery for cervical degenerative disk disease by the posterior approach.

Osteotomies in ankylosing spondylitis: where, how many, and how much?

INTRODUCTION

This article presents the current concepts of correction of spinal deformity in ankylosing spondylitis (AS) patients. Untreated AS can be a debilitating disease. In a few patients, disease progression results in severe spinal deformity affecting not only the thoracolumbar, but also the cervical spine. Surgery for correction in AS patients has a long history. With the advent of modern instrumentation, standardization of surgical and anesthesiologic techniques, surgical safety and corrective results could be improved and experiences from lumbar osteotomies could be transferred to the cervical spine.

METHODS

This article presents the current concepts of correction of spinal deformity in AS patients. In particular, questions regarding the localization and number of osteotomies, the optimal surgical target angle as well as planning and prediction of postoperative alignment are discussed.

RESULTS

Insight into recent technical developments, current challenges with correction and geometric analysis of center of rotation (COR) in cervical 3-column osteotomies (3CO) will be presented.

CONCLUSION

The article should encourage readers to improve surgical correction efficacy and provide a better understanding of correction geometry in 3CO for thoracolumbar and cervical spinal deformities.

Posterior Vertebral Column Resection With Intraoperative Manual Retraction for the Treatment of Posttubercular Kyphosis in Upper Thoracic Spine or Cervicothoracic Junction

STUDY DESIGN

This is a case-series.

OBJECTIVE

To evaluate the clinical and radiologic outcomes of posterior vertebral column resection (PVCR) for treatment of posttubercular kyphosis in upper thoracic spine and cervicothoracic junction (CTJ).

SUMMARY OF BACKGROUND DATA

Surgical management of severe posttubercular kyphosis in upper thoracic spine or CTJ is challenging. A new technique that combines PVCR and intraoperative manual traction in a single procedure, was developed to maximize the correction rate and minimize the risk of dural buckling and spinal cord injury. However, the safety and effectiveness of the procedure is yet to be established.

MATERIALS AND METHODS

Ten patients with upper thoracic or CTJ posttubercular kyphosis, who underwent PVCR with intraoperative manual traction between December 2008 and 2013, were studied retrospectively. Data pertaining to operation time, blood loss, and perioperative complications were collected. Outcomes were evaluated using the visual analog scale; the 12-Item Short Form Health Survey (SF-12), Mental Component Summary, and SF-12 Physical Component Summary. Neurological status was assessed using American Spinal Injury Association (ASIA) impairment scale. Radiologic outcomes including fusion and deformity correction were assessed using plain radiography and computed tomography.

RESULTS

The average duration of follow-up was 53.6±7.2 months. Average operating time and blood loss were 263±35.3 minutes and 2490±569 mL, respectively. Visual analog scale score for back pain, SF-12 Mental Component Summary, and Physical Component Summary showed significant improvement postoperatively. Kyphosis improved from a preoperative average of 73.6±13.1 degrees to an average of 37.9±8.7 degrees at final follow-up (correction rate: 48.5%). No postoperative neurological deterioration was observed based on the ASIA score. As of the last follow-up, solid fusion was not achieved only in 1 patient.

CONCLUSIONS

PVCR with intraoperative manual traction is a safe and effective procedure for treatment of upper thoracic or CTJ posttubercular kyphosis.

LEVEL OF EVIDENCE

Level 4.

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

Cervical kyphotic deformity represents a difficult to treat pathology often arising from multiple factors including, but not limited to, traumatic injuries, degenerative changes, and ankylosing spondylitis. Furthermore, treatment of these deformities becomes increasingly difficult with any preexisting instrumentation. Currently, several options exist to treat these severe deformities, with the Smith-Petersen osteotomy and C-7 pedicle subtraction osteotomy being the most frequently used approaches. However, these techniques come with significant risk to the patient including nerve root injury as well as compression of the vertebral arteries. The authors here report on a series of 4 patients with rigid cervical deformity who underwent T-1 pedicle subtraction osteotomy. The authors review the relevant literature and provide a novel, less risky, and potentially more corrective approach for treating cervical deformities.

Asymmetric C7 pedicle subtraction osteotomy for correction of rigid cervical coronal imbalance secondary to post-traumatic heterotopic ossification: a case report, description of a novel surgical technique, and literature review

PURPOSE

Deformities of the cervical spine are uncommon in the coronal plane. In this report, a unique case of a 31-year-old male with a fixed, 30° left coronal deformity due to heterotopic ossification 3 years status post poly-trauma was treated with an asymmetric C7 pedicle subtraction osteotomy (PSO).

METHODS

Case report.

RESULTS

Pre-operatively, the patient had a fixed 45-degree left tilt of his neck and radiographs demonstrated a rigid 30° scoliosis, 7 cm coronal imbalance, and 4 cm negative sagittal balance, diffuse bridging bone between the spinous processes and the facet joints of C5 to T1 bilaterally. An asymmetric C7 PSO with C2-T3 posterior spinal fusion was completed without complication. There was residual 9° coronal deformity, 2.9 cm left coronal imbalance, and 2.3 cm sagittal imbalance. He had a marked improvement in his function, as assessed by the SF-36 physical component score (pre-op 31.1; post-op 44.7) and mental component score (pre-op 46.0; post-op 66.8). Post-operatively, neck disability index scores also improved (pre-op 38; post-op 16). Although the patient passed away from a drug overdose 14 months post-operatively, he did not report neck pain, he had not sought evaluation from another physician for his neck, and he had not undergone a subsequent neck operation before his passing.

CONCLUSION

In this one patient, an asymmetric C7 PSO was performed safely. While it was effective in addressing a fixed cervical coronal imbalance, its efficacy and safety profile should be confirmed in larger cohorts.

Do Ponte Osteotomies Enhance Correction in Adolescent Idiopathic Scoliosis? An Analysis of 191 Lenke 1A and 1B Curves

STUDY DESIGN

Retrospective review of a prospectively collected multicenter database of patients with adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To determine if Ponte osteotomies improve correction in Lenke 1A and 1B AIS curves treated with pedicle screws.

SUMMARY OF BACKGROUND DATA

There is little data studying the risks and benefits of Ponte osteotomies in AIS.

METHODS

We identified patients with Lenke 1A and 1B curve types treated with pedicle screw constructs and a 2-year follow-up. They were grouped based on whether they did (PO) or did not (NoPO) have Ponte osteotomies. Demographic, surgical, and radiographic data collected preoperatively and at 2 years were statistically analyzed using unpaired Student t test and Fisher exact test.

RESULTS

One hundred ninety-one patients met the inclusion criteria (mean age of 14.7 ± 2.2 years), and among those, 125 patients (65.4%) had Ponte osteotomies (average of 4.3 ± 1.5 Pontes per patient). The patients treated with Ponte osteotomies had similar clinical and radiographic parameters (major Cobb: PO = 51.5°, NoPO = 50.8°, p = .6) to the patients who did not have Ponte osteotomies except that they had stiffer and more lordotic curves (Flexibility Index: PO = 47.3%, NoPO = 54.5%, p = .04; T5-T12 kyphosis: PO = 18.7°, NoPO = 23.2°, p = .02). At 2 years, the patients treated with Ponte osteotomies had significantly better thoracic Cobb angle correction (Correction Index: PO = 67.1%, NoPO = 61.8%, p = .01) and an increase in T5-T12 kyphosis (PO = +3.0°, NoPO = -0.4°, p = .045). The Ponte group demonstrated greater rib prominence correction (PO = 53.2%, NoPO = 38.4%, p = .02). There were no neurologic events in this cohort.

CONCLUSIONS

Although the use of Ponte osteotomies was not randomized, these data suggest that greater deformity correction in all 3 planes may be possible when Ponte osteotomies are performed for the stiffer and more lordotic Lenke 1A and 1B curves. The clinical significance of these overall small statistical differences remains to be determined.

LEVEL OF EVIDENCE

III.

Comparison of Smith-Petersen osteotomy versus pedicle subtraction osteotomy versus anterior-posterior osteotomy types for the correction of cervical spine deformities

STUDY DESIGN

Retrospective case controlled study.

OBJECTIVE

To describe the amount of correction obtained with different types of osteotomies in the cervical spine when treating cervical deformity.

SUMMARY OF BACKGROUND DATA

Although the corrective power of various osteotomies in the thoracic and lumbar spine are well described, there are no reports in the literature on the corrective capabilities of osteotomies in the cervical spine to guide preoperative planning for cervical and cervicothoracic deformities.

METHODS

Patients who underwent cervical osteotomies for cervical deformity were identified in a 10-year period from 2000 to 2010. Demographics, surgery type, osteotomy type (Smith-Petersen Osteotomy [SPO], pedicle subtraction osteotomy [PSO], anterior-osteotomy [ATO]), operative details, and radiographs were collected for preoperative and ultimate postoperative time points. Cervical lordosis and basion plumb line were collected to assess angular and translational corrections.

RESULTS

A total of 61 patients had surgery for cervical deformity in the study period. The mean angular correction generated through 1 SPO was 10.1° per level (range, 1.0°-24.9°/level) and the mean translational correction was 1.8 cm (range, 0.5-4.0 cm/SPO). A PSO generated a mean angular correction of 34.5° (range, 28.2°- 80.0°/level, maximum 1/case) per PSO and translational correction of 2.5 cm per PSO (range, 0.2-5.6 cm). An ATO generated a mean angular correction of 17.1° per osteotomy (range, 3.5°-32.1°/level) and translational correction of 1.0 cm per osteotomy (range, 0.1-3.0 cm/level; total, 0.5-3 cm). Combined ATO and SPO with posterior cervical fusion generated a mean angular correction of 27.8° per osteotomy (range, 3.7°-66.7°/level) and translational correction of 2.6 cm per osteotomy (range, 0.2-7.0 cm/level).

CONCLUSION

Posteriorly based osteotomies provided better translational correction than ATOs. The angular correction achieved by 1 PSO was similar to ATO+SPOs. ATO+SPOs provided equal or better corrections than isolated PSOs, with equal length of stay and less estimated blood loss.

LEVEL OF EVIDENCE

4.

Anterior cervical osteotomy for fixed cervical deformities

STUDY DESIGN

Description of surgical technique with case series.

OBJECTIVE

To describe the surgical management of fixed cervical deformities using an anterior osteotomy of the cervical spine.

SUMMARY OF BACKGROUND DATA

Although posteriorly based osteotomies of the cervical spine have been described in the past, there are no reports of the surgical technique for performing an anterior osteotomy of the cervical spine for fixed cervical deformities.

METHODS

Description of a single surgeon's technique for performing an anterior cervical osteotomy and his experience in performing this technique from 2000 to 2010 in a consecutive series of patients. Demographics, operative details, and clinical/radiographical outcomes were collected. The cohort was separated into 2 groups. Group 1 had anterior osteotomy only with or without posterior instrumentation whereas group 2 had anterior osteotomy and Smith-Petersen osteotomies with posterior instrumentation.

RESULTS

A total of 38 patients (group 1 = 17, group 2 = 21) underwent an anterior osteotomy in the study period with an average follow-up of 3.4 years (range, 1.0-6.3 yr). All but 7 cases were revision cases. Group 1 had shorter length of surgery and less estimated blood loss than group 2 (length of surgery 220 vs. 313 min, P < 0.01; estimated blood loss 189 vs. 294 mL, P = 0.02).The mean angular correction achieved in group 1 was less than that of group 2, although not statistically significant (23° vs. 33°, P = 0.15). There was less mean translational correction achieved in group 1 compared with group 2 (1.3 vs. 3.7 cm, P = 0.03). Both groups had improvements in the neck disability index with surgery and were similar between groups (20 vs. 19.7, P = 0.78). There were no neurological complications or intraoperative neuromonitoring changes in either group.

CONCLUSION

The use of an anterior osteotomy in the cervical spine is safe and effective for the correction of fixed deformities of the cervical spine. When necessary, Smith-Petersen osteotomies can add to the angular and translational correction to achieve a satisfying outcome for patients.

LEVEL OF EVIDENCE

4.

A standardized nomenclature for cervical spine soft-tissue release and osteotomy for deformity correction

Object

Cervical spine osteotomies are powerful techniques to correct rigid cervical spine deformity. Many variations exist, however, and there is no current standardized system with which to describe and classify cervical osteotomies. This complicates the ability to compare outcomes across procedures and studies. The authors' objective was to establish a universal nomenclature for cervical spine osteotomies to provide a common language among spine surgeons.

Methods

A proposed nomenclature with 7 anatomical grades of increasing extent of bone/soft tissue resection and destabilization was designed. The highest grade of resection is termed the major osteotomy, and an approach modifier is used to denote the surgical approach(es), including anterior (A), posterior (P), anterior-posterior (AP), posterior-anterior (PA), anterior-posterior-anterior (APA), and posterior-anterior-posterior (PAP). For cases in which multiple grades of osteotomies were performed, the highest grade is termed the major osteotomy, and lower-grade osteotomies are termed minor osteotomies. The nomenclature was evaluated by 11 reviewers through 25 different radiographic clinical cases. The review was performed twice, separated by a minimum 1-week interval. Reliability was assessed using Fleiss kappa coefficients.

Results

The average intrarater reliability was classified as “almost perfect agreement” for the major osteotomy (0.89 [range 0.60–1.00]) and approach modifier (0.99 [0.95–1.00]); it was classified as “moderate agreement” for the minor osteotomy (0.73 [range 0.41–1.00]). The average interrater reliability for the 2 readings was the following: major osteotomy, 0.87 (“almost perfect agreement”); approach modifier, 0.99 (“almost perfect agreement”); and minor osteotomy, 0.55 (“moderate agreement”). Analysis of only major osteotomy plus approach modifier yielded a classification that was “almost perfect” with an average intrarater reliability of 0.90 (0.63–1.00) and an interrater reliability of 0.88 and 0.86 for the two reviews.

Conclusions

The proposed cervical spine osteotomy nomenclature provides the surgeon with a simple, standard description of the various cervical osteotomies. The reliability analysis demonstrated that this system is consistent and directly applicable. Future work will evaluate the relationship between this system and health-related quality of life metrics.

Non-instrumented correction of cervicothoracic kyphosis in ankylosing spondylitis: a critical analysis on the results of open-wedge osteotomy C7-T1 with gradual Halo-Thoracic-Cast based correction

INTRODUCTION

With progression of cervicothoracic kyphosis (CTK), ankylosing spondylitis (AS) patients suffer functional disability. Surgical correction still poses neurologic risks, while evidence of an ideal technique preventing its complications is weak.

MATERIALS AND METHODS

We report our results with non-instrumented correction in perspective of a review of literature, serving as an important historical control. Database review identified 18 AS patients with CTK correction. After application of a Halo-Thoracic-Cast (HTC) patients underwent posterior non-instrumented open-wedge osteotomy at C7/T1 and osteotomy closure by threaded HTC-rod adjustments. Postoperative gradual HTC correction was continued for 2-4 weeks. Patients were invited for follow-up and medical charts were reviewed for demographics, surgical details, complications and outcomes. The patients' preoperative, postoperative, before HTC removal and follow-up photographs were analyzed for the Chin-Brow-Vertical-Angle (CBVA), radiographs for the CTK angle.

RESULTS

Patients' age was 50 ± 11 years, follow-up was 37 ± 47 months and CBVA correction was 25° ± 9° (p < 0.000001). The final radiographic correction at follow-up was 20° ± 11° (p = 0.00002). At the latest follow-up, three patients judged their outcome as excellent, nine good, three moderate and one poor. Upon invitation, seven patients appeared with follow-up averaging 87 months. Neck-pain disability index was 8 ± 14 %. Two patients died, three were lost, one had revision elsewhere and five just had a routine follow-up. Six patients sustained a minor and ten a major complication. Revisions were indicated in five patients including infection, C8-radiculopathy and neurologic events by translation at the osteotomy. A total of 44 % of patients showed translation at the osteotomy indicating acute surgery with instrumentation twice after osteotomy closure, three patients had a revision posterior decompression and instrumented fusion for sequels related to translation.

CONCLUSION

With the non-instrumented HTC-based technique, average CBVA correction of 25° was achieved and all patients were ambulatory at follow-up. However, regarding translation at the osteotomy, loss of correction, morbidity of the HTC and lack of control at the osteotomy instrumentation-based correction and instrumented fusion seem to be preferable.

A sterile-freehand reduction technique for corrective osteotomy of fixed cervical kyphosis

STUDY DESIGN

A technical note and a retrospective review of cervical osteotomy using an innovative reduction technique.

OBJECTIVE

To present the clinical and radiological outcomes and effectiveness of the sterile-freehand reduction technique for cervical osteotomy. SUMMARY OF BACKGROUD DATA: For a successful osteotomy, controlled reduction of deformity after complete release of bony deformity is the most critical step. Conventional "unscrubbed-scrubbed" manual reduction techniques necessitate multiple releases and retightening of the clamp and are inconvenient for the surgeon to control the force and monitor the surgical field closely.

METHODS

A total of 7 consecutive patients (5 male and 2 female; mean age, 52.6 yr) who underwent corrective osteotomy of the fixed cervical kyphosis by a single surgeon were enrolled. Radiographically, C2-C7 sagittal and coronal angle, and the chin-brow vertical angle were measured. In the prone position, the entire head and the Gardner-Wells tong were included in the surgical field, and a sterile rope was connected to a weight through a hole made in the surgical drape. After complete release of bony element and fixation of the caudal part of osteotomy with a prebent lordotic rod, the operator held the tong with right hand and gradually reduced the deformity to place the rod within the screw heads on the cranial part of osteotomy under close visual observation, with the support of the caudal part with left hand. RESULTS.: The type of osteotomy performed was pedicle-subtraction osteotomy in 5 cases and anterior-release-posterior osteotomy in 2 cases. The mean correction angle was 39.7° (28°-63°) on the sagittal plane and 9.3° (0°-16°) on the coronal plane. The mean correction of the chin-brow vertical angle was 37.1° (18°-61°). There was no neurovascular complication.

CONCLUSION

Using the sterile-freehand reduction technique, the operator can obtain a safe, controlled reduction with close monitoring of the surgical field. The technique is potentially a simple and effective method to provide stable, 3-dimensional reduction for corrective osteotomies of the cervical spine.

Technique of cervicothoracic junction pedicle subtraction osteotomy for cervical sagittal imbalance: report of 11 cases

Object

Sagittal imbalance of the cervicothoracic spine often causes severe pain and loss of horizontal gaze. Historically, the Smith-Peterson osteotomy has been used to restore sagittal balance. Cervicothoracic junction pedicle subtraction osteotomy (PSO) offers more controlled closure and greater biomechanical stability but has been infrequently reported in the literature. This study details the cervicothoracic PSO technique in 11 cases and correlates clinical kyphosis (chin-brow to vertical angle [CBVA]) with radiographic measurements.

Methods

Between February 2008 and September 2010, 11 patients (mean age 70 years) underwent a modified PSO (10 at C-7, 1 at T-1) for treatment of sagittal imbalance. Preoperative and postoperative sagittal plane radiographic measurements were made. The CBVA was measured on clinical photographs. Operative technique and perioperative correction were reported for all 11 patients and long-term follow-up data was reported for 9 patients, in whom the mean duration of follow-up was 23 months. Outcome measures used for these 9 patients were the Neck Disability Index, the 36-Item Short Form Health Survey (SF-36), and a visual analog scale for neck pain.

Results

The mean values for estimated blood loss, surgical time, and hospital stay in the 11 patients were 1100 ml, 4.3 hours, and 9.9 days, respectively. The mean preoperative and immediate postoperative values (± SD) for cervical sagittal imbalance were 7.9 ± 1.4 cm and 3.4 ± 1.7 cm. The mean overall correction was 4.5 ± 1.5 cm (42.8%), the mean PSO correction 19.0°, and the mean CBVA correction 36.7°. There was essentially no correlation between preoperative C2–T1 radiographic kyphosis and preoperative CBVA (R2 = 0.0165). There was a moderate correlation with PSO correction angle and postoperative CBVA (R2 = 0.38). There was a significant decrease in both the Neck Disability Index (51.1 to 38.6, p = 0.03) and visual analog scale scores for neck pain (8.1 to 3.9, p = 0.0021). The SF-36 physical component summary scores increased by 18.4% (30.2 to 35.8) with no neurological complications.

Conclusions

The cervicothoracic junction PSO is a safe and effective procedure for the management of cervicothoracic kyphotic deformity. It results in excellent correction of cervical kyphosis and CBVA with a controlled closure and improvement in health-related quality-of-life measures even at early time points.