Anterior fusion alone compared with combined anterior and posterior fusion for the treatment of degenerative cervical kyphosis

Acute Progressive Pediatric Post-Traumatic Kyphotic Deformity

Cervical kyphosis is a rare entity with challenging management due to the limitations of pediatric age, along with a growing spine. The pathogenesis is made up of a large group of congenital, syndromic and acquired deformities after posterior element deterioration or as a result of previous trauma or surgery. In rare progressive cases, kyphotic deformities may result in severe "chin-on-chest" deformities with severe limitations. The pathogenesis of progression to severe kyphotic deformity after minor hyperflexion trauma is not clear without an obvious MR pathology; it is most likely multifactorial. The authors present the case of a six-month progression of a pediatric cervical kyphotic deformity caused by a cervical spine hyperflexion injury, and an MR evaluation without the pathology of disc or major ligaments. Surgical therapy with a posterior fixation and fusion, together with the preservation of the anterior growing zones of the cervical spine, are potentially beneficial strategies to achieve an excellent curve correction and an optimal long-term clinical outcome in this age group.

Assessment of Biomechanical Advantages in Combined Anterior-Posterior Cervical Spine Surgery by Radiological Outcomes: Pedicle Screws over Lateral Mass Screws

BACKGROUND

The combined anterior-posterior approach has shown good clinical outcomes for multilevel cervical diseases. This work describes the biomechanical advantage of cervical-pedicle-screw fixation over lateral-mass-screw fixation in combined anterior-posterior cases.

METHOD

Seventy-six patients who received combined cervical surgery from June 2013 to December 2020 were included. The patients were divided into two groups: the lateral-mass-screw group (LMS) and the pedicle-screw group (PPS). Radiological outcomes were assessed with lateral cervical spine X-rays for evaluating sagittal alignment, subsidence, and bone remodeling.

RESULTS

At 1 year postoperatively, the numbers of patients whose C2-C7 cervical lordosis was less than 20 degrees decreased by more in the PPS group (p-value = 0.001). The amount of vertical-length change from immediately to 1 year postsurgery was less in the PPS group than in the LMS group (p-value = 0.030). The mean vertebral-body-width change was larger in the PPS group than in the LMS group during 3 months to 1 year postsurgery (p-value = 0.000).

CONCLUSIONS

In combined anterior-posterior cervical surgery cases, maintenance of cervical lordosis and protection of the vertebral body from subsidence were better with the pedicle-screw fixation. More bone remodeling occurred when using the pedicle-screw fixation method.

Patient-Reported Outcomes Following Anterior and Posterior Surgical Approaches for Multilevel Cervical Myelopathy

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To compare health-related quality of life (HRQoL) outcomes between approach techniques for the treatment of multilevel degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Both anterior and posterior approaches for the surgical treatment of cervical myelopathy are successful techniques in the treatment of myelopathy. However, the optimal treatment has yet to be determined, especially for multilevel disease, as the different approaches have separate complication profiles and potentially different impacts on HRQoL metrics.

MATERIALS AND METHODS

Retrospective review of a prospectively managed single institution database of patient-reported outcome measures after 3 and 4-level anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF) for DCM. The electronic medical record was reviewed for patient baseline characteristics and surgical outcomes whereas preoperative radiographs were analyzed for baseline cervical lordosis and sagittal balance. Bivariate and multivariate statistical analyses were performed to compare the two groups.

RESULTS

We identified 153 patients treated by ACDF and 43 patients treated by PCDF. Patients in the ACDF cohort were younger (60.1 ± 9.8 vs . 65.8 ± 6.9 yr; P < 0.001), had a lower overall comorbidity burden (Charlson Comorbidity Index: 2.25 ± 1.61 vs . 3.07 ± 1.64; P = 0.002), and were more likely to have a 3-level fusion (79.7% vs . 30.2%; P < 0.001), myeloradiculopathy (42.5% vs . 23.3%; P = 0.034), and cervical kyphosis (25.7% vs . 7.69%; P = 0.027). Patients undergoing an ACDF had significantly more improvement in their neck disability index after surgery (-14.28 vs . -3.02; P = 0.001), and this relationship was maintained on multivariate analysis with PCDF being independently associated with a worse neck disability index (+8.83; P = 0.025). Patients undergoing an ACDF also experienced more improvement in visual analog score neck pain after surgery (-2.94 vs . -1.47; P = 0.025) by bivariate analysis.

CONCLUSIONS

Our data suggest that patients undergoing an ACDF or PCDF for multilevel DCM have similar outcomes after surgery.

Outcomes Following Anterior Cervical Discectomy and Fusion in Patients With Ehlers-Danlos Syndrome

STUDY DESIGN

Retrospective database analysis.

OBJECTIVES

To study postoperative complication rates following anterior cervical discectomy and fusion (ACDF) in patients with Ehlers-Danlos syndrome (EDS) compared with patients without EDS.

METHODS

The Mariner database was utilized to identify patients with EDS undergoing one or two level anterior cervical discectomy and fusion (ACDF). Postoperative short-term outcomes assessed included medical complications, readmissions, and ED-visits within 90 days of surgery. Additionally, surgical complications including wound complications, surgical site infection, one- and two-year anterior revision along with posterior revision, pseudarthrosis, and hardware failure within 2 years were assessed. Multivariate logistic regression was used to adjust for demographic variables, comorbidities and number of levels operated on.

RESULTS

The present study identified 533 patients in the EDS group and 2634 patients in the matched control group. EDS patients undergoing ACDF are at an increased risk for 90-day major medical complications (OR 3.31; P < .001). EDS patients were also found to be associated with surgical complications including wound complications (OR 2.94; P < .001), surgical site infection (OR 8.60; P < .001) within 90 days, pseudarthrosis (OR 2.33; P < .001), instrument failure (OR 4.03; P < .001), anterior revision (OR 22.87; P < .001), and posterior revision (OR 3.17; P < .001) within 2 years.

CONCLUSIONS

EDS is associated with higher rates of both medical and surgical complications following ACDF. Spine surgeons should be cognizant of the increased risks in this population to provide appropriate preoperative counseling and enhanced perioperative medical management.

Comparing Combined Anterior and Posterior to Posterior-Only Decompression and Fusion Crossing the Cervico-Thoracic Junction in Octogenarians

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of the study was to compare early complication, morbidity and mortality risks associated with fusion surgery crossing the cervico-thoracic junction in patients aged over 80 years undergoing combined anterior and posterior approach versus a posterior-only approach.

METHODS

We retrospectively identified octogenarian patients with myelopathy who underwent fusion crossing the cervico-thoracic junction. Patient demographics, Nurick score, surgical characteristics, complications, hospital course, early outcome and 90-day mortality were collected. Comorbidities were classified using the age-adjusted Charlson Comorbidity Index (AACCI). Radiographic measurements for deformity correction included the C2-C7 sagittal Cobb angle, C2-7 sagittal vertical axis and T1 slope pre- and postoperatively.

RESULTS

Out of 8,521 surgically treated patients, 12 octogenarian patients had a combined anterior and posterior approach (AP group) and 14 were treated from posterior-only (P group). Mean age was 81.4 ± 1.2 and 82.5 ± 2.7 years, respectively. There was no significant difference in Nurick scores between the groups (P > 0.05). The major complication risk in the AP group was significantly higher, requiring PEG tube placement due to severe dysphagia in 4 patients (33%) compared to none in the P group. A greater improvement in cervical lordosis could be achieved through a combined approach. The 90-day mortality risk was 8% for the AP group and 0% for the P group.

CONCLUSIONS

A combined anterior and posterior approach is associated with a significantly higher major complication rate and can result in severe dysphagia requiring PEG tube placement in one-third of patients over 80 years of age.

Classification(s) of Cervical Deformity

Cervical spine deformities (CSD) are complex surgical issues with currently heterogenous management strategies. The classification of CSD is still an evolving field. Rudimentary classification schemas were initially proposed in the late 20th century but were largely informal and based on the underlying etiology (i.e. , postsurgical, traumatic, or inflammatory). The first formal classification schema was proposed by Ames et al. in 2015 who established a standard nomenclature for describing these deformities. This classification system established 5 deformity descriptors based on curve apex location (cervical, cervicothoracic, thoracic, craniovertebral junctional, and coronal deformities) and 5 deformity modifiers which helped surgeons utilize a standard language when discussing CSD patients. Koller et al. in 2019 subsequently established a classification system for patients with rigid cervical kyphosis based on regional and global sagittal alignment. Most recently, Kim et al. in 2020 proposed an updated classification system utilizing dynamic cervical spine imaging to guide surgical treatment of CSD patients. It identified 4 major groups of deformities - (1) those with "flat-neck" deformities caused by cervical lordosis T1 slope mismatch; (2) those with focal kyphotic deformities between 2 cervical vertebrae; (3) those with cervicothoracic deformities caused by large T1 slope; and (4) those with coronal deformities. Group 2 deformities most often required combined anterior-posterior approaches with short constructs, and group 3 deformities most often required posterior-only approaches with 3-column osteotomies.

The effect of cervical intervertebral disc degeneration on the motion path of instantaneous center of rotation at degenerated and adjacent segments: A finite element analysis

BACKGROUND

The motion path of instantaneous center of rotation (ICR) is a crucial kinematic parameter to dynamically characterize cervical spine intervertebral patterns of motion; however, few studies have evaluated the effect of cervical disc degeneration (CDD) on ICR motion path. The purpose of this study was to investigate the effect of CDD on the ICR motion path of degenerated and adjacent segments.

METHOD

A validated nonlinear three-dimensional finite element (FE) model of a healthy adult cervical spine was used. Progressive degeneration was simulated with six FE models by modifying intervertebral disc height and material properties, anterior osteophyte size, and degree of endplate sclerosis at the C5-C6 level. All models were subjected to a pure moment of 1 Nm and a compressive follower load of 73.6 N to simulate physical motion. ICR motion paths were compared among different models.

RESULTS

The normal FE model results were consistent with those of previous studies. In degenerative models, average ICR motion paths shifted significantly anterior at the degenerated segment (β = 0.27 mm; 95% CI: 0.22, 0.32) and posterior at the proximal adjacent segment (β = -0.09 mm; 95% CI: -0.15, -0.02) than those of the normal model.

CONCLUSION

CDD significantly affected ICR motion paths at the degenerated and proximal adjacent segments. The changes at adjacent segments may be a result of compensatory mechanisms to maintain the balance of the cervical spine. Surgical treatment planning should take into account the restoration of ICR motion path to normal. These findings could provide a basis for prosthesis design and clinical practice.

Circumferential Operations of the Cervical Spine

Generally, a combined anterior and posterior cervical approach is associated with significant morbidity since it requires an extended operative time, greater intraoperative blood loss, and both anterior- and posterior-related surgical complications. However, there are some instances where a circumferential cervical fusion can be advantageous. Our objective is to discuss the indications for circumferential cervical spine procedures. A narrative review of the literature was performed. We include the indications for circumferential cervical approaches of the senior author (KDR). Indications for circumferential approaches include: (1) high-risk patients for pseudoarthrosis, (2) cervical deformity (e.g., degenerative, posttraumatic, cervicothoracic kyphosis), (3) cervical spine metastases (especially those with multilevel involvement), (4) cervical spine infection, (5) unstable cervical trauma, (6) movement disorders and cerebral palsy, (7) Multiply operated patient (especially postlaminectomy kyphosis and patients with massive ossification of the posterior longitudinal ligament), and when (8) early fusion is desirable. Circumferential procedures may be useful in many different cervical spine conditions requiring surgery. Despite its advantages, particularly with reducing the risk for pseudarthrosis, the benefits of a combined approach must be weighed against the risks associated with a dual approach. With appropriate preoperative planning, intraoperative decision-making, and surgical techniques, excellent clinical outcomes can be achieved.

Posterior Surgical Techniques for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations

Objective

This study was conducted to determine and recommend the most up-to-date information on the indications, complications, and outcomes of posterior surgical treatments for cervical spondylotic myelopathy (CSM) on the basis of a literature review.

Methods

A comprehensive literature search was performed, using the MEDLINE (PubMed), the Cochrane Register of Controlled Trials, and Web of Science databases, for peer-reviewed articles published in English during the last 10 years.

Results

Posterior techniques, which include laminectomy alone, laminectomy with fusion, and laminoplasty, are often used in patients with involvement of 3 or more levels. Posterior decompression for CSM is effective for improving patients’ neurological function. Complications resulting from posterior cervical spine surgery include injury to the spinal cord and nerve roots, complications related to posterior screw fixation or instrumentation, C5 palsy, spring-back closure of lamina, and postlaminectomy kyphosis.

Conclusion

It is necessary to consider multiple factors when deciding on the appropriate operation for a particular patient. Surgeons need to tailor preoperative discussions to ensure that patients are aware of these facts. Further research is needed on the cost-to-benefit analysis of various surgical approaches, the comparative efficacy of surgical approaches using various techniques, and long-term outcomes, as current knowledge is deficient in this regard.

Acute progressive adolescent idiopathic cervical kyphosis: case report

Acute progressive adolescent idiopathic cervical kyphosis (AICK) is rare, and its treatment strategy is controversial. The authors present a case of AICK successfully treated with preoperative halo-gravity traction, followed by combined anterior-posterior surgery. A 15-year-old girl with no relevant past or family history presented with axial neck pain without any cause. A few months after the development of cervical myelopathy, cervical kyphosis progressed to 71° despite conservative treatment. CT scanning demonstrated osteophyte formation at the anterior aspect of the vertebral body. MRI showed a forward migration of the spinal cord with a ratio (C/M ratio) between the anteroposterior diameter of the medulla-pons junction and the spinal cord at the apex of the kyphosis of 0.27. After 2 weeks of preoperative halo-gravity traction, anterior release and posterior fusion was performed. After surgery, cervical kyphosis was corrected to 0°, and cervical myelopathy improved. One year after surgery, the patient was neurologically intact, and bony union and improved cervical alignment were observed. Preoperative halo-gravity traction followed by combined anterior-posterior surgery led to safe and effective correction. Osteophyte formation at the anterior aspect of the vertebral body and the C/M ratio were useful in predicting the progression of AICK.

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.

One-Stage Wedge Osteotomy Through Posterolateral Approach for Cervical Postlaminectomy Kyphosis with Anterior Fusion

OBJECTIVE

Osteotomy through anterior exposure is challenging with severe complications for upper cervical kyphosis (CK), especially for cases with previous anterior fusion. A novel technique comprising 1-stage osteotomy via a posterolateral-only approach is introduced for treatment of CK secondary to C2-4 laminectomy for neurofibroma removal and subsequent anterior fusion.

METHODS

A 42-year-old man presented with progressive numbness and weakness of upper and lower limbs. As an adolescent, he underwent posterior laminectomy and neurofibroma excision without effective fixation and anterior C2-4 vertebra fusion 6 years later. Sagittal computed tomography indicated that Cobb angle between C2 and C6 was 68° with complete fusion between C2 and C4 vertebral bodies. Secondary CK was diagnosed based on medical history and radiographic findings, and modified Japanese Orthopaedic Association scale score was 10. Piezosurgery was used for osteotomy by shortening the vertebral height through posterolateral approach after cervical pedicle screw placement. Occipitocervical fusion was performed with compression between C2 and C4.

RESULTS

Cobb angle was adjusted to 8° postoperatively. Modified Japanese Orthopaedic Association score increased to 14 with obvious muscle strength improvement. The 6-month postoperative x-ray indicated good position of C2-4 vertebrae and occipitocervical fixation system. No neurologic complications or local recurrence was found at final follow-up at 8 months. The patient returned to work in his full capacity.

CONCLUSIONS

Preliminary outcomes reveal wedge osteotomy via piezosurgery through a posterolateral-only approach is feasible and effective in revision surgery for upper CK with previous anterior fusion.

An algorithmic strategy of surgical intervention for cervical degenerative kyphosis

PURPOSE

Correction surgery for cervical degenerative kyphosis (CDK) may carry a greater risk of causing neural complications such as spinal cord injury and C5 nerve palsy because spinal canal stenosis, osteoarthritis of the facet, and consequent foraminal stenosis may coexist with CDK. We have produced an algorithmic strategy of surgical intervention for CDK, and report the outcome.

METHODS

Thirty-one patients who underwent correction surgery for CDK, with a kyphotic angle of 20° or more (from 20 to 74) were involved. An algorithmic surgical strategy is shown. Clinical and radiological outcomes were examined amongst the groups.

RESULTS

Recovery rate of the JOA score was a mean of 44%. Preoperative kyphotic angle and correction angle were; 24.4°and 26.5°in P, 38.4°and 41.1°in AP, and 42.0°and 46.9°in PAP respectively. No spinal cord injury was found. Five cases of C5 nerve palsy occurred in P, and one in AP. Four cases of C5 palsy occurred in seven patients in PAP, although prophylactic foraminotomy was performed. All C5 palsy patients recovered fully at follow-up.

CONCLUSIONS

This study showed that our algorithmic surgical strategy for CDK is acceptable because we obtained good outcomes, and no catastrophic complications occurred. Although we did not intend to obtain excessive postoperative lordosis, we still had several incidence of C5 nerve palsy. We have to be aware of this incidence in PAP, which required a massive range of realignment. The incidence occurred even after we performed prophylactic foraminotomy, however, this procedure may lessen the severity of C5 palsy because those were all transient.

Pseudarthrosis of the Cervical Spine: Risk Factors, Diagnosis and Management

Cervical myelopathy and radiculopathy are common pathologies that often improve with spinal decompression and fusion. Postoperative complications include pseudarthrosis, which can be challenging to diagnose and manage. We reviewed the literature with regard to risk factors, diagnosis, controversies, and management of cervical pseudarthrosis.

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

OBJECT

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.

METHODS

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.

RESULTS

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 < 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%.

CONCLUSIONS

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.

Single-stage Anterior and Posterior Fusion Surgery for Correction of Cervical Kyphotic Deformity Using Intervertebral Cages and Cervical Lateral Mass Screws: Postoperative Changes in Total Spine Sagittal Alignment in Three Cases with a Minimum Follow-up of Five Years

The surgical treatment of cervical kyphotic deformity remains challenging. As a surgical method that is safer and avoids major complications, the authors present a procedure of single-stage anterior and posterior fusion to correct cervical kyphosis using anterior interbody fusion cages without plating, as illustrated by three consecutive cases. Case 1 was a 78-year-old woman who presented with a dropped head caused by degeneration of her cervical spine. Case 2 was a 54-year-old woman with athetoid cerebral palsy. She presented with cervical myelopathy and cervical kyphosis. Case 3 was a 71-year-old woman with cervical kyphotic deformity following a laminectomy. All three patients underwent anterior release and interbody fusion with cages and posterior fusion with cervical lateral mass screw (LMS) fixation. Postoperative radiographs showed that correction of kyphosis was 39° in case 1, 43° in case 2, and 39° in case 3. In all three cases, improvement of symptoms was established without major perioperative complications, solid fusion was achieved, and no loss of correction was observed at a minimum follow-up of 61 months. We also report that preoperative total spine sagittal malalignment was improved after corrective surgery for cervical kyphosis and was maintained at the latest follow-up in all three cases. The combination of anterior fusion cages and LMS is considered a safe and effective procedure in cases of severe cervical kyphotic deformity. Preoperative total spine sagittal malalignment improved, accompanied by correction of cervical kyphosis, and was maintained at last follow-up in all three cases.

Is it possible to eliminate the plate-related problems and still achieve satisfactory outcome after multilevel anterior cervical discectomy?

BACKGROUND

Stand-alone cage-assisted anterior cervical discectomy and fusion (ACDF) has proved to be safe and effective procedure for treatment of mono-segmental cervical degenerative stenosis (CDS). However, the success rate has reported to decline as the number of levels increases. The aim of this prospective study was to evaluate the short-term results of multilevel ACDF using stand-alone polyetheretherketone (PEEK) cages.

PATIENTS AND METHODS

Twenty-eight patients (16 males and 12 females; mean age 40.5 years) of symptomatic multilevel CDS were enroled in this study and completed a 2-year post-operative follow-up. All patients underwent contiguous multilevel ACDF, using indirect decompression and stand-alone PEEK cages, between 2009 and 2012. Ten patients underwent two-level fusions (group I), ten underwent three-level fusions (group II), and eight underwent four-level fusions (group III). The visual analogue scales of neck and arm pain and Odom's criteria were used to evaluate clinical outcomes. Radiological evaluation was done to evaluate: fusion, cervical sagittal angle (CSA) and cage subsidence.

RESULTS

There was a statistical significant improvement in clinical parameters and radiological CSA values in all groups post-operatively. This improvement was well maintained till final follow-up. Subsidence and non-union were encountered in seven and two fusion levels, respectively, with no significant differences between groups. All patients were satisfied and none of them had major complications or required revision surgery.

CONCLUSION

With proper patient selection, meticulous surgical technique and strict post-operative cervical bracing, the less-invasive indirect anterior cervical decompression technique augmented with stand-alone PEEK cage-assisted ACDF is an efficient and safe method for the treatment of multilevel CDS.

Dysphagia following combined anterior-posterior cervical spine surgeries

OBJECT

This study was undertaken to evaluate the incidence of and risk factors associated with the development of dysphagia following same-day combined anterior-posterior cervical spine surgeries.

METHODS

The records of 30 consecutive patients who underwent same-day combined anterior-posterior cervical spine surgery were reviewed. The presence of dysphagia was assessed by a formalized screening protocol using history/clinical presentation and a bedside swallowing test, followed by formal evaluation by speech and language pathologists and/or fiberoptic endoscopic evaluation of swallowing/modified barium swallow when necessary. Age, sex, previous cervical surgeries, diagnoses, duration of procedure, specific vertebral levels and number of levels operated on, degree of sagittal curve correction, use of anterior plate, estimated blood loss, use of recombinant human bone morphogenetic protein-2 (rhBMP-2), and length of hospital stay following procedures were analyzed.

RESULTS

In the immediate postoperative period, 13 patients (43.3%) developed dysphagia. Outpatient follow-up data were available for 11 patients with dysphagia, and within this subset, all cases of dysphagia resolved subjectively within 12 months following surgery. The mean numbers of anterior levels surgically treated in patients with and without dysphagia were 5.1 and 4.0, respectively (p = 0.004). All patients (100%) with dysphagia had an anterior procedure that extended above C-4, compared with 58.8% of patients without dysphagia (p = 0.010). Patients with dysphagia had significantly greater mean correction of C2-7 lordosis than patients without dysphagia (p = 0.020). The postoperative sagittal occiput-C2 angle and the change in this angle were not significantly associated with the occurrence of dysphagia (p = 0.530 and p = 0.711, respectively). Patients with postoperative dysphagia had significantly longer hospital stays than those who did not develop dysphagia (p = 0.004). No other significant difference between the dysphagia and no-dysphagia groups was identified; differences with respect to history of previous anterior cervical surgery (p = 0.141), use of an anterior plate (p = 0.613), and mean length of anterior cervical operative time (p = 0.541) were not significant.

CONCLUSIONS

The incidence of dysphagia following combined anterior-posterior cervical surgery in this study was comparable to that of previous reports. The risk factors for dysphagia that were identified in this study were increased number of anterior levels exposed, anterior surgery that extended above C-4, and increased surgical correction of C2-7 lordosis.

Analysis of cervical sagittal alignment after screw-rod fixation

BACKGROUND

The use of posterior instrumentation constructs is well established for subaxial cervical stabilizations/fusions. The importance of global and regional sagittal alignment has become increasingly recognized.

OBJECTIVE

To perform an analysis using computed tomography scans to determine the effect of posterior instrumentation on postoperative cervical sagittal alignment at long-term follow-up.

METHODS

Over a period of 6 years, 56 consecutive patients (38 male and 18 female patients; mean age, 47 years) underwent cervical screw-rod fixation. Plain radiographs, computed tomography scans, and magnetic resonance images were analyzed preoperatively to assess sagittal alignment (C2-C7). Postoperatively, computed tomography scans and serial radiographs were obtained in all patients. With the use of independent observers, changes in sagittal alignment were determined by comparing the preoperative and postoperative imaging studies.

RESULTS

In total, 390 screws were placed in the cervical spines of 56 patients. Definitive radiographic fusion was detected in all 56 patients (100%). There were no incidences of instrumentation failures or lucencies surrounding any screws. Patients with preoperative kyphosis (n = 19; mean, +9.9°) improved their sagittal alignment by 6.5° (final mean, +3.4°), whereas patients with preoperative lordosis (n = 37; mean -15.44°) maintained their lordosis (final mean, -15.3°). Mean duration of follow-up was 32.5 months.

CONCLUSION

Radiographic analysis showed lateral mass fixation to be safe and effective. Certain operative techniques allowed substantial deformity correction and maintenance of long-term correction of deformity. Screw-rod fixation may be an effective method for maintaining lordotic cervical alignment in previously lordotic patients and for significantly correcting kyphotic deformity in patients with a preoperative kyphosis.

Ossification of the posterior longitudinal ligament: a review of literature

Ossification of the posterior longitudinal ligament (OPLL) is most commonly found in men, in the elderly, and in Asian patients. The disease can start with mild or no symptoms, but some patients progress slowly to develop symptoms of myelopathy. An accurate diagnosis through the use plain radiograph, computed tomography, and magnetic resonance imaging findings is very important to monitor the development of symptoms and to make decisions regarding a treatment plan. When symptoms are mild and non-progressive, conservative treatments and periodic observations are good enough, but once symptoms of myelopathy are present and neurologic symptoms are progressive, the treatment of choice is surgery to relieve spinal cord compression. Surgical management of OPLL continues to be controversial. Each surgical technique has some advantages and disadvantages, and the choice of operation should be decided carefully with various considerations. The patient's neurological condition, location and extent of pathology, cervical kyphosis, presence or absence of accompanied instability, and the individual surgeon's experience must be an important factors that should be considered before surgery.