Anterior endoscopically assisted transcervical reconstruction of the upper cervical spine

Navigated Anterior Full-Endoscopic Transcervical Approach Odontoidectomy for Traumatic Posterior Atlantoaxial Dislocation Without Odontoid Fracture

BACKGROUND AND IMPORTANCE

Complete posterior atlantoaxial dislocation (PAAD) with an unfractured odontoid process is a rare condition where a dislocated but intact odontoid process is positioned ventrally to the anterior arch of C1. This lesion is related to transverse and alar ligament rupture secondary to hyperextension and rotatory traumatic injury and is often associated with neurological deficit. The treatment strategy remains controversial, and in many cases, odontoidectomy is required. Traditional approaches for odontoidectomy (transnasal and transoral) are technically demanding and are related to several complications. This article describes a 360° reduction and stabilization technique through a navigated anterior full-endoscopic transcervical approach (nAFETA) as a novel technique for odontoidectomy and C1-C2 anterior transarticular fixation supplemented with posterior fusion.

CLINICAL PRESENTATION

A 21-year-old man presented to the emergency room by ambulance after a motorcycle accident. On evaluation, incomplete ASIA B spinal cord injury was documented. Imaging revealed a complete PAAD. We performed a two-staged procedure, a nAFETA odontoidectomy plus C1-C2 anterior transarticular fixation followed by posterior C1-C2 wired fusion. At a 2-year follow-up, the patient had a 10-point Oswestry Disability Index score and neurological improvement to ASIA E.

CONCLUSION

PAAD can be successfully treated through minimally invasive nAFETA. Noteworthy, the risks of the transoral and endonasal routes were avoided through this approach. In addition, nAFETA allows anterior transarticular fixation during the same procedure providing spinal stability. Further studies are required to expand the use of nAFETA in this field.

Release, reduction, and fixation of one-stage posterior approach for basilar invagination with irreducible atlantoaxial dislocation

PURPOSE

We evaluate the efficacy, safety and indications of single stage posterior release, reduction, and fixation of basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD).

MATERIALS AND METHODS

Seventeen patients with BI and IAAD consecutively underwent one-stage release, reduction, and fixation by a posterior approach from July 2000 to June 2015 were followed up for at least 12 months. There were 8 males. Mean age was 56 35.2 ± 13.8 years (range 12-56). The clinical symptoms and signs of the patients were recorded. Pre- and postoperative imaging examinations were performed. Neurological function was assessed using the Japanese Orthopedic Association (JOA) and Ranawat scores.

RESULTS

Average follow-up time was 47.4 months (12-97 months). The JOA score increased from preoperative 4-10 (8.06 ± 2.52) to postoperative 13-16 (15.20 ± 0.62). The preoperative Chamberlain line, McRae line, Wackenheim line, atlantodens interval, and cervico medullary angle were 12.52 ± 5.17 mm, 6.59 ± 3.04 mm, 6.96 ± 4.32 mm, 9.88 ± 1.93 mm, and 115.35 ± 12.40°, respectively. The postoperative values were 2.0 ± 3.67 mm, -3.06 ± 1.85 mm, -1.76 ± 2.88 mm, 1.17 ± 1.18 mm, and 136.76 ± 11.44°, respectively.

CONCLUSION

One-stage release, reduction, and fixation for patients with BI and IAAD through a posterior approach is safe and efficient.

Endoscopy-assisted anterior cervical debridement combined with posterior fixation and fusion for the treatment of upper cervical spine tuberculosis: a retrospective feasibility study

Background

This retrospective study aimed to determine the feasibility and efficacy of endoscopy-assisted anterior cervical debridement combined with posterior fixation and fusion in patients with upper cervical spine tuberculosis.

Methods

Between June 2008 and January 2016, 17 patients (10 men and 7 women) with upper cervical spine tuberculosis underwent endoscopy-assisted anterior cervical debridement combined with posterior fixation and fusion. Anti-tuberculosis treatment was administered for 2–4 weeks preoperatively and 12–18 months postoperatively. The clinical and radiographic data of the patients were analyzed.

Results

The operation was successfully completed in all patients. Neck pain and stiffness were relieved after the surgery in all patients. The mean operation time was 210.0 ± 21.2 min, and the mean intraoperative blood loss was 364.7 ± 49.6 mL. The mean follow-up duration was 68.1 ± 6.7 months. The erythrocyte sedimentation rate returned to normal by 3 months postoperatively. Visual analog scale scores for neck pain were significantly lower postoperatively than preoperatively. All patients had significant postoperative neurological improvement. Patient-reported outcomes, as measured using the Kirkaldy-Willis criteria, were as follows: excellent, 12 patients; good, 4 patients; fair, 1 patient; and poor, 0 patients. Bone fusion was achieved at 10.9 ± 1.9 months after the surgery; no cases of instrument loosening or fracture occurred.

Conclusion

Endoscopy-assisted anterior cervical debridement combined with posterior fixation and fusion is a feasible and effective surgical method for the treatment of upper cervical spine tuberculosis. It can be used to restore upper cervical spine stability and facilitate spinal healing.

Multiprofessional Management of Giant Cell Tumors in the Cervical Spine: A Systematic Review

BACKGROUND

Giant cell tumors of the bone (GCTB) are rare bone tumors, especially in the cervical spine. Generally considered benign, local aggressiveness and metastatic growth have been described. Surgical concepts for GCTB are challenged by complex neurovascular anatomy. Specific clinical management guidelines are nonexistent. This systematic review aims to compile existing evidence on the treatment of GCTB of the cervical spine.

METHODS

Four electronic databases were searched: Medline, Embase, Web of Science, and Cochrane Library. All clinical studies reporting the treatment of GCTB in the human cervical spine in English language were found eligible for review.

RESULTS

Seven studies were included in the synthesis including a total number of 54 patients. Of those patients, 46 (85%) were treated for naive nonrecurrent GCTB. Only 1 study is considered a cohort study; all other studies were case reports. Generally, intralesional procedures were performed in 13 (24%) cases. Subtotal resections were reported for 11 (20%) patients. Twenty-eight (52%) patients were surgically treated with piecemeal resection, en-bloc resection, or spondylectomy. Thirty-six (67%) patients underwent adjuvant radiotherapy. A combination of radiotherapy and chemotherapy was reported in 2 (4%) cases. Bisphosphonates were prescribed for 9 (17%) patients. Inconsistent reporting of outcome data did not allow for comparative analyses.

CONCLUSIONS

Best available evidence suggests that the most aggressive surgical approach should be the main goal of any GCTB surgery. No specific adjuvant or neoadjuvant treatment can be recommended as superior due to a lack of comparative data. Therapeutic approaches need to be planned thoroughly on an individual basis.

Endoscopic Transnasal Odontoidectomy for Ventral Decompression of the Craniovertebral Junction: Surgical Technique and Clinical Outcome in a Case Series of 19 Patients

BACKGROUND

Abnormalities and pathologies of the craniovertebral junction as well as space-occupying lesions of the odontoid process can result in myelopathy symptoms. A staged procedure with posterior stabilization and anterior transnasal endoscopic decompression is recently considered a less invasive alternative to the transoral approach. We present a considerably large case series focused on the operative technique and the long-term neurological clinical outcome.

OBJECTIVE

To determine the safety and efficacy of odontoidectomy performed via an endoscopic transnasal approach.

METHODS

We retrospectively reviewed all patients treated in our neurosurgical department from January 2009 to January 2020. Demographics, pre- and postoperative clinical status, and operative technique and complications were extracted and analyzed.

RESULTS

In total, 22 transnasal operations were performed in 19 patients from January 2009 to January 2020. All but one patient underwent posterior C1-C2 instrumentation prior to the anterior transnasal computed tomography (CT)-navigated full-endoscopic decompression. The median duration of symptoms before surgery was 3 mo. Complications occurred in 1 patient who died from septic organ failure because of his initial diagnosis of osteomyelitis. Postoperative CT imaging showed sufficient decompression in 16 patients, and 3 patients underwent a transnasal endoscopic re-decompression (16%).

CONCLUSION

Transnasal endoscopic odontoidectomy presents a safe procedure with a satisfying clinical and radiological postoperative outcome.

Anterior endoscopically assisted bone grafting for iatrogenic distraction of odontoid fracture after percutaneous anterior screw fixation: A case report

RATIONALE

The complication of iatrogenic distraction of odontoid fracture after anterior screw fixation has not been reported in the literature. We treated the patient with endoscopically assisted bone grafting with good results. The new technique was not reported in the management of odontoid fracture or nonunion before.

PATIENT CONCERNS

A 22-year-old man presented with neck pain after a motorcycle crash. The cervical spine radiograph and computed tomographic scan demonstrated the base of dens displaced 2 mm anteriorly.

DIAGNOSES

Radiographic images showed a type II odontoid fracture.

INTERVENTIONS

The patient was treated by percutaneous anterior screw fixation. The postoperative radiograph and CT demonstrated an iatrogenic distraction of the odontoid with a gap of 6 mm.The follow-up radiograph did not show any sign of bone union 1 month and a half later. A revision surgery was given by anterior endoscopically assisted bone grafting. The patient was encouraged to sit out of bed immediately after the surgery with the protection of a soft cervical collar for 3 months.

OUTCOMES

No complications such as neural structures or vascular injuries were found. Bone union was achieved at the 1-year follow-up CT scans. Physical examination showed a full range of motion in the neck.

LESSONS

We reported a case of iatrogenic odontoid distraction that was managed by anterior endoscopically assisted bone grafting. It is a technically feasible and minimally invasive procedure.

Selection of surgical procedures for basilar invagination with atlantoaxial dislocation

BACKGROUND CONTEXT

Basilar invagination (BI) is a malformation of craniovertebral junction. However, surgical procedures on BI with atlantoaxial dislocation (AAD) remain controversial.

PURPOSE

This research aimed to investigate the selection of surgical procedures and its significance in the surgical treatment of patients with BI and AAD.

STUDY DESIGN

This was a retrospective study.

PATIENT SAMPLE

This study enrolled 33 patients who were diagnosed with BI and AAD and were followed up for at least 6 months.

OUTCOME MEASURE

All of the patients were assessed for neurologic recovery observation in terms of Japanese Orthopaedic Association scores and Odom criteria. X-ray, magnetic resonance imaging, or computed tomography scanning was used to determine reduction, compression, bone graft, and internal fixation before and after operation.

METHODS

Thirty-three patients who suffered from BI with AAD were treated in our department from July 2000 to October 2014. Preoperatively, the patients were divided into two types on the basis of whether dislocation was reduced after anesthesia and traction were performed: reducible dislocation (Type A) and irreducible dislocation (Type B). Reducible dislocation was further divided into two subtypes: full reducible dislocation (Type A1) and partial reducible dislocation (Type A2). Type A1 patients were treated with direct posterior fixation and fusion after traction and reduction. Type A2 patients received posterior atlantoaxial release, fixation, and fusion under traction. Type B patients underwent transoral atlantoaxial release, posterior fixation, and fusion.

RESULTS

There were 5 Type A1 patients, 10 Type A2 patients, and 18 Type B patients treated in accordance with the proposed scheme. Postoperatively, sufficient reduction and decompression were achieved for all cases. Two Type B patients died. Other patients were followed up from 6 months to 42 months (average=16.6 months); follow-up results showed sufficient decompression, effective fixation and fusion, and no reduction loss. The Japanese Orthopaedic Association Score increased from preoperative 4-12 (average, 7.8) to postoperative 10-17 (average, 14.3), and neurologic recovery was satisfactory.

CONCLUSIONS

Under traction, simple posterior fixation and fusion were effective for Type A patients suffering from BI with AAD; anterior atlantoaxial release and posterior fixation and fusion were effective for Type B patients with BI and AAD.

A microsurgical anterior cervical approach and the immediate impact of mechanical retractors: A case control study

Introduction:

A microsurgical anterior cervical approach with discectomy and fusion (MACDF) is one of the most widely used procedures for treating radicular disorders. This approach is highly successful; however, it is not free from complications. These can be associated with soft tissue injuries.

Aim of the Study:

The recognition of the risks for these complications should be identified for timely prevention and safe treatment.

Materials and Methods:

Study Design: Retrospective case control study. This study includes a retrospective case series of 37 patients, paying special attention to immediate complications related to the use of mechanical retraction of soft tissue (dysphagia, dysphonia, esophageal lesions and local hematoma); and a comparative analysis of the outcomes after changes in the retraction method.

Results:

All selected cases had a positive neurological symptom response in relation to neuropathic pain. Dysphagia and dysphonia were found during the first 72 h in 94.1% of the cases in which automatic mechanical retraction was used for more than one hour during the surgical procedure. A radical change was noted in the reduction of the symptoms after the use of only manual protective blades without automatic mechanical retraction: 5.1% dysphagia and 0% dysphonia in the immediate post-operative period, P = 0.001.

Conclusions:

Soft tissue damage due to the use of automatic retractors in MACDF is not minor and leads to general discomfort in the patient in spite of good neurological results. These problems most often occur when automatic retractors are used continuously for more than 1 hour, as well as when they are used in multiple levels. Dysphagia, dysphonia and local pain decreased with the use of transient manual blades for retraction, and with intermittent release following minimally invasive principles.

Endoscopic transcervical anterior release and posterior fixation in the treatment of irreducible vertical atlantoaxial dislocation

Vertical atlantoaxial dislocation is a type of atlantoaxial instability with upper cervical spinal cord compression. The transoral ondontoid resection with posterior fixation is the gold standard for ventral decompression. Results are satisfying though surgery can be challenging due to its invasiveness. The endoscopic transcervical anterior release could provide sufficient ventral decompression with less collateral damage. In the illustrative case, anatomic reduction was achieved with significant improvement in neurological function and radiographic parameters. Endoscopic transcervical anterior release and posterior fixation appears to be a viable and interesting alternative for the treatment of vertical atlantoaxial dislocation in properly selected individuals, and its implementation could significantly reduce the post-surgical complications.

The influence of cervical spine position on the three anterior endoscopic approaches to the craniovertebral junction: an imaging study

BACKGROUND CONTEXT

Three endoscopic anterior approaches, the transnasal, transoral, and transcervical approaches, are used for ventral lesions of the craniovertebral junction and have been compared regarding surgical working distances and approach angles. However, how the position of the cervical spine influences the depths of surgical corridors and approach angles for the three approaches has not been evaluated.

PURPOSE

To evaluate the depths of surgical corridors and the approach angles for the three endoscopic approaches, taking the influence of cervical spine position into account.

STUDY DESIGN

A radiographic study comparing three anterior endoscopic approaches to the craniovertebral junction.

PATIENT SAMPLE

Cervical extension and flexion radiographs for 34 patients and cross-sectional computed tomography scans for 30 additional patients were assessed.

OUTCOME MEASURES

The depths of the surgical corridors and the approach angles for the three endoscopic approaches in the midsagittal planes.

METHODS

We determined the mean angles of the surgical trajectories for the endoscopic transoral and transcervical approaches on cervical extension and flexion radiographs. In addition, we measured the depths of the surgical corridors and the approach angles for the three approaches in the midsagittal plane.

RESULTS

The average depths of surgical corridors were as follows: endonasal, 93.65 mm; transoral, 85.27 mm; transcervical, 62.97 mm (in extension). The average approach angles were as follows: endonasal, 31.22°; transoral, 30.87°; transcervical, 36.58° (in extension).

CONCLUSIONS

The position of the cervical spine does not influence the surgical convenience of the endoscopic transnasal approach, but it can influence the endoscopic transoral and transcervical approaches, especially the latter. The endoscopic transcervical approach offers several advantages over the endoscopic transoral and endonasal approaches.

Novel surgical classification and treatment strategy for atlantoaxial dislocations

STUDY DESIGN

Retrospective study of 904 patients with a diagnosis of atlantoaxial dislocation (AAD), using a novel surgical classification and treatment strategy.

OBJECTIVE

To describe a novel surgical classification and treatment strategy for AADs.

SUMMARY OF BACKGROUND DATA

AADs can result from a variety of etiologies, yet no comprehensive classification has been accepted that guides treatment. Because of the rarity of the cases, however, the treatment strategy has also been debated.

METHODS

During a period of 12 years, a total of 904 patients with a diagnosis of AAD were recruited from a single academic institution. According to the treatment algorithm that included preoperative evaluation using dynamic radiograph, reconstructive computed tomography, and skeletal traction test, the cases were classified into 4 types: I to IV. Types I and II were fused in the reduced position from a posterior approach. Type III, which were irreducible dislocations, were converted to reducible dislocations using a transoral atlantoaxial release, followed by a posterior fusion. Type IV presented with bony dislocations and required transoral osseous decompressions prior to posterior fusion.

RESULTS

Four hundred seventy-two cases were classified as type I, 160 as type II, 268 as type III, and 4 cases as type IV. Follow-up was in the range of 2 to 12 years (average: 60.5 mo). Eight hundred and ninety-nine cases (99.4%) achieved a solid atlantoaxial fusion. Anatomic atlantoaxial reduction was achieved in 892 cases (98.7%), whereas 12 cases had a partial reduction. Neurological improvement was seen in 84.1% (512/609) of the patients with myelopathy. The overall complication rate was 9.1% (82/949).

CONCLUSION

Our surgical classification and treatment strategy for AADs was applied in those 904 cases and associated with excellent clinical results with a minimal risk of complications.

LEVEL OF EVIDENCE

4.

The naso-axial line: a new method of accurately predicting the inferior limit of the endoscopic endonasal approach to the craniovertebral junction

BACKGROUND

The endoscopic endonasal approach (EEA) has developed as an emerging surgical corridor to the craniovertebral junction (CVJ). In addition to understanding its indications and surgical anatomy, the ability to predict its inferior limit is vital for optimal surgical planning.

OBJECTIVE

To develop a method that accurately predicts the inferior limit of the EEA on the CVJ radiologically and to compare this with other currently used methods.

METHODS

Predissection computerized tomographic scans of 9 cadaver heads were used to delineate a novel line, the naso-axial line (NAxL), to predict the inferior EEA limit on the upper cervical spine. A previously described method with the use of the nasopalatine line (NPL or Kassam line) was also used. On computerized tomographic scans obtained following dissection of the EEA, the predicted inferior limits were compared with the actual extent of dissection.

RESULTS

The postdissection inferior EEA limit ranged from the dens tip to the upper half of the C2 body, which matched the limit predicted by NAxL, with no statistically significant difference between them. In contrast to the NAxL, the NPL predicted a significantly lower EEA limit (P < .001), ranging from the lower half of the C2 body to the superior end plate of C3.

CONCLUSION

The novel NAxL more accurately predicts the inferior limit of the EEA than the NPL. This method, which can be easily used on preoperative sagittal scans, accounts for variations in patients' anatomy and can aid surgeons in the assessment of the EEA to address caudal CVJ pathology.