The Halifax Interlaminar Clamp for posterior cervical fusion: initial experience in the United Kingdom

Advances in surgical treatment for atlantoaxial instability focusing on rheumatoid arthritis: Analysis of a series of 67 patients

AIM

An estimated 88% of rheumatoid arthritis (RA) patients experience various degrees of cervical spine involvement. The excessive movement of the atlantoaxial joint, which connects the occiput to the upper cervical spine, results in atlantoaxial instability (AAI). AAI stabilization is usually achieved by C1 lateral mass-to-C2 pedicle screw-rod fixation (LC1-PC2 fixation), which is technically challenging in RA patients who often show destructive changes in anatomical structures. This study aimed to analyze the clinical results and operative experiences of C1-C2 surgery, with emphasis on the advancement of image-guided surgery and augmented reality (AR) assisted navigation.

METHODS

We presented our two decades of experience in the surgical management of AAI from April 2004 to November 2022.

RESULTS

We have performed surgery on 67 patients with AAI, including 21 traumatic odontoid fractures, 20 degenerative osteoarthritis, 11 inflammatory diseases of RA, 5 congenital anomalies of the os odontoideum, 2 unknown etiologies, 2 movement disorders, 2 previous implant failures, 2 osteomyelitis, 1 ankylosing spondylitis, and 1 tumor. Beginning in 2007, we performed LC1-PC2 fixation under C-arm fluoroscopy. As part of the progress in spinal surgery, since 2011 we used surgical navigation from presurgical planning to intraoperative navigation, using the preoperative computed tomography (CT) -based image-guided BrainLab navigation system. In 2021, we began using intraoperative CT scan and microscope-based AR navigation.

CONCLUSION

The technical complexities of C1-C2 surgery can be mitigated by CT-based image-guided surgery and microscope-based AR navigation, to improve accuracy in screw placement and overall clinical outcomes, particularly in RA patients with AAI.

Type II Odontoid Fracture: a case series highlighting the treatment strategies

BACKGROUND

A type II odontoid fracture, if unstable, can cause spinal cord damage. In this case, it is essential to choose the correct treatment-but the issues of what the correct treatment is and which of the different surgical options is best are quite controversial. In this paper we present strategies for treatment of type II odontoid fracture.

MATERIALS AND METHODS

Thirty consecutive cases of type II odontoid fracture were treated at the Division of Neurosurgery at Villa Sofia Hospital in Palermo (23 cases) and at the Neurosurgical Clinic, University Hospital of Palermo (seven cases), from January 2011 to August 2016. Four patients were treated with external immobilization. Twenty-six patients underwent a surgical procedure.

RESULTS

There was no mortality related to the surgical procedure. One patient had a pre- and postoperative neurological deficit, and remained tetraparetic. Follow-up radiological studies in the surgically treated group showed bone union in 21 patients and stable fibrous union in one.

CONCLUSION

In our and other authors' experience, when the direction of the fracture line is down and forward, external immobilization can be sufficient for healing. Anterior odontoid screw fixation can be considered the treatment of choice for unstable odontoid fractures (with a horizontal, down and back, or comminuted fracture line) without dislocation or with dislocation less than 7 mm.When the odontoid fracture is associated with a Jefferson fracture or dislocation greater than 7 mm, stabilization of C1-C2 may be necessary. In this case, placement of screws in the dens and in the joints through a single approach represents the most valid technique.In the case of an inveterate fracture of the dens with severe C1-C2 dislocation, the surgical operation that offers the best prospects is posterior stabilization, utilizing the Guo technique.

Single-stage Anterior Release and Sequential Posterior Fusion for Irreducible Atlantoaxial Dislocation

STUDY DESIGN

A retrospective study.

OBJECTIVE

To introduce the method of single-stage anterior release and reduction with posterior fusion in irreducible atlantoaxial dislocation (IAAD) and to evaluate the clinical effects of this surgery.

SUMMARY OF BACKGROUND DATA

In previous clinical studies, several techniques have been introduced to manage IAAD. But all these treatments have intrinsic disadvantages. A single-stage anterior release and reduction with posterior fusion can offer a new alternative which can avoid these disadvantages.

METHODS

From January 2003 to January 2009, 22 cases of IAAD were diagnosed consecutively. Anterior atlantoaxial release was performed through anterior retropharyngeal approach, after traction reduction conducted on the monitoring of C-arm fluoroscopy. C1-C2 were then fixed posteriorly and fused by single stage. Neurological status was evaluated using the Japanese Orthopaedic Association scoring system.

RESULTS

All patients were observed for an average of 32 months, ranging from 15 to 40 months. All cases achieved anatomic reduction and solid fusion. The Japanese Orthopaedic Association score of 12 patients with myelopathy improved from 8.3 to 13.9, 6 months postoperatively, and the mean improving rate was 87.5%. No graft or implant-related complications were observed in any patient during the entire follow-up period.

CONCLUSIONS

The method of single-stage anterior release and reduction with posterior fusion is an effective method for management of IAAD, proving its value as a technique for achieving complete reduction with solid bony fusion.

Posterior atlantoaxial fixation: a review of all techniques

BACKGROUND CONTEXT

Posterior atlantoaxial fixation is an effective treatment for atlantoaxial instability. Great advancements on posterior atlantoaxial fixation techniques have been made in the past decades. However, there is no article reviewing all the posterior atlantoaxial fixation techniques yet.

PURPOSE

The aim was to review the evolution and advancements of posterior atlantoaxial fixation.

STUDY DESIGN

This was a literature review.

METHODS

The application of all posterior fixation techniques in atlantoaxial stabilization, including wiring techniques, interlaminar clamp fixation, transarticular fixation, screw-plate systems, screw-rod systems, and hook-screw systems, are reviewed and discussed. Recent advancements on the novel technique of atlantoaxial fixation are described. The combination of the C1 and C2 screws in screw-rod systems are described in detail.

RESULTS

All fixation techniques are useful. The screw-rod system appears to be the most popular approach. However, many novel or modified fixation methods have been introduced in recent years.

CONCLUSIONS

Great advancements on posterior atlantoaxial fixation techniques have been made in the past decades. The wiring technique and interlaminar clamps technique have fallen out of favor because of the development of newer and superior fixation techniques. The C1-C2 transarticular screw technique may remain the gold standard for atlantoaxial fusion, whereas screw-rod systems, especially the C1 pedicle screw combined with C2 pedicle/pars screw fixation, have become the most popular fixation techniques. Hook-screw systems are alternatives for atlantoaxial fixation.

Rigid variety occiput/C1-C2-C3 internal fixation in pediatric population

PURPOSE

The purpose of this study was to review our experience of rigid internal fixation of craniovertebral junction in pediatric population. A new technique of reduction of basilar invagination with atlantoaxial dislocation is described. To the best of our knowledge and available scientific literature, this technique has not yet been described in younger patients.

METHODS

We have managed 27 children by rigid variety of occiput/C1-C2-C3 internal fixation of various craniovertebral junction pathologies. All patients were subjected to thin cuts of computed tomography with 3D reconstruction for selecting appropriate rigid construct. Eight children had occiput-C2, 3 had occiput-C2-C3, and 16 had C1-C2 hardware constuct. One patient of C1-C2-plate fixation had section of C2 nerve root ganglia. Basilar invagination with atlantoaxial dislocation was reduced by new distraction/compression techniques.

RESULTS

Improvement in clinical features and correction of deformity with solid hardware construct were seen in all patients. Follow-up period ranged from 5-72 months. One patient was lost to follow-up, and one case died of compression of vertebral artery at C1 lateral mass. Patients of myelopathy had recovery rate of 90.9%. Hardware failure was seen in one patient, and wound infection was observed in two cases.

CONCLUSIONS

Rigid variety of occiput/C1-C2 internal fixation is a safe and effective method in the management of variety of craniovertebral pathologies in pediatric population. This new technique of reduction of basilar invagination with atlantoaxilal dislocation from posterior approach may alleviate the need of high morbity associated with surgical procedure like transoral odontoidectomy in younger patients.

Axis fractures

BACKGROUND

Traumatic fractures of the second cervical vertebra are common, representing nearly 20% of all acute cervical spinal fracture-dislocation injuries. They are divided into 3 distinct injury patterns: odontoid fractures, hangman's fracture injuries, and fractures of the axis body, involving all other fracture injuries to the C2 vertebra.

OBJECTIVE

An evidence-based overview of the medical and surgical treatment strategies for each axis fracture injury sub-type.

RESULTS

Current medical and surgical management of traumatic fractures of the axis.

Open reduction of irreducible atlantoaxial dislocation by transoral anterior atlantoaxial release and posterior internal fixation

STUDY DESIGN

A retrospective study of surgical outcome of 33 patients with irreducible atlantoaxial dislocation (IAAD).

OBJECTIVE

To evaluate the safety efficacy of one stage anterior release and posterior fixation and fusion to reduce and stabilize IAAD.

SUMMARY OF BACKGROUND DATA

The traditional treatment of symptomatic IAAD is ventral decompression by transoral approach. This procedure is accompanied with high morbidity and mortality. It does not correct the swan neck deformity, which could precipitate the degenerative changes in the lower cervical spine. Our hypotheses were that it is the contraction of the muscles, ligaments, and capsules of atlantoaxial joint that prevent reduction, and that most of IAADs might be reduced by anterior atlantoaxial joint release without the odontoid resection, and that further reduction and stabilization might be achieved by special posterior fixation.

METHODS

A consecutive series of 33 patients with IAAD were surgically treated. Dislocation or reduction was assessed before surgery, immediately after surgery, and at the final fol5786-up. Etiology, instrumentation, levels fused, and complications were documented. All patients were assessed clinically for neurologic recovery by Odom's method.

RESULTS

The mean age was 32 years (range, 7-63 years). The pathology included os odontoideum in 8 patients, occipitalization of C1 in 19 patients, malunion of odontoid fracture in 5, and relaxation of transverse ligament of atlas in 1. Twenty five patients presented neurologic signs and symptoms. Anterior release was performed without odontoid resection in all cases. Four patients underwent transarticular C1-C2 screw fixation, 3 had C1-C2 pedicle screw and plate fixation, and 26 required occipitocervical fixation. Twenty-five cases resulted in an anatomic reduction, 8 had partial reduction. Complication included one dysphagia and two nasal phonations. The mean follow-up period was 33.7 months (range, 24-55 months). There was no pseudarthrosis, and all but 1 of the patients with neurologic deficit showed improvement.

CONCLUSION

This series has demonstrated the safety and efficacy of the transoral anterior atlantoaxial release in the reduction of IAAD. Most of the so-called irreducible/fixed AAD could become reducible after anterior release without odontoid resection. The posterior short-segment atlantoaxial or occipitocervical fixation, especially the plate screw instrumentation, could achieve further reduction and provide immediate stabilization. One-stage anterior release and posterior instrumentation and fusion are a safe and reliable operation in experienced hands.

Atlantoaxial fusion using anterior transarticular screw fixation of C1-C2: technical innovation and biomechanical study

This study is an attempt to describe a new technique for anterior transarticular screw fixation of the atlantoaxial joints, and to compare the stability of this construct to posterior transarticular screw fixation with and without laminar cerclage wiring. Nine human cadaveric specimens were included in this study. The C1-C2 motion segment was instrumented using either anterior transarticular screws (group 1), posterior transarticular screws alone (group 2), or posterior screws with interlaminar cerclage wires (group 3). Using an unconstrained mechanical testing machine, the specimens were tested in rotation, lateral bending, and flexion-extension using nondestructive loads of +/-2 N m. The specimens were also tested in translation using nondestructive loads of +/-100 N. All values for the three groups with regards to anterior-posterior displacement, rotation, and lateral bending were similar as determined using a Kruskal-Wallis rank sum test with a significance level of p<0.05. The only significant difference was registered in flexion-extension where the cerclage wire added some strength to the construct. Anterior transarticular screw fixation of the atlantoaxial spine has several advantages over posterior fixation techniques, and is as stable as posterior transarticular fixation in all clinically significant planes of motion. The addition of posterior interlaminar cerclage wiring further improves resistance to flexion-extension forces. Anterior transarticular screw fixation of the atlantoaxial joint is a useful technique for achieving C1-C2 stabilization.

Acute atlanto-axial post-operative subluxation following posterior C1/2 fusion

Two cases referred with acute post-operative C1/2 subluxation following posterior fusion are reported. Both cases had initial treatment for atlanto-axial instability with posterior cable (Brooks and interspinous) and graft techniques, and placed immediately in a Philadelphia collar. One case was found to have subluxed immediately post-operatively when failing to breathe following reversal of anaesthetic agents, and despite immediate realignment and reoperation was left with a significant quadriparesis. The other patient was noted to have subluxed on routine X-ray on day 4, and had no neurological deficit before or after reoperation. Risk factors for this dangerous complication are discussed and the techniques of C1/2 posterior fusion and stabilization are reviewed in detail. Surgeons performing atlanto-axial stabilization procedures should be familiar with and have expertize in the complete range of techniques described and choose the one most appropriate for the patient's individual requirements.

One-stage posterior decompression and fusion using a Luque rod for occipito-cervical instability and neural compression

STUDY DESIGN

Original article.

OBJECTIVE

The authors present seven cases who underwent one-stage suboccipital, C1 and/or C2 posterior decompression and fusion by Luque rod, wiring and autogenic bone graft for occipito-cervical instability and neural compression.

SETTING

Chang Gung University and Medical Center at Kaohsiung, Taiwan.

METHOD

Since January 1996, 20 cases of craniovertebral and upper cervical spinal instability were encountered. Seven of these cases had no neurological improvment under Cone-Barton Skeletal traction. Imaging studies revealed poor reduction with persistent neural compression. One patient underwent unsuccessful anterior trans-oral vertebrectomy for decompression. All patients underwent posterior suboccipital craniectomy, C1 and/or C2 laminectomy for decompression. Contoured Luque rod with wiring and autogeneic bone graft was used for craniocervical fusion. After surgical treatment, halo-vest or sterno-occipito-mandibular immobilizer (SOMI) was used for 3-6 months.

RESULTS

Suboccipital craniectomy and C1 laminectomy could afford a 30-50% increment of anteroposterior diameter in the neural canal and effective decompression of the low medulla and cord. All patients made neurological improvement. The ASIA-MIS scores improved from pre-operative 49 (mean) to 78. Four patients can walk without any support. There were no major complications except for one case requiring readjustment of the halo-vest brace.

CONCLUSION

The authors recommend this procedure as one choice for relieving craniocervical instability with neurological compromise. A programmed rehabilitation will afford better neurological improvement.

Differential treatment in acute upper cervical spine injuries: a critical review of a single-institution series

BACKGROUND

A single-institution series of injuries of the upper cervical spine are analyzed retrospectively and the literature relevant to the topic is reviewed.

METHODS

Seventy patients (34 female, 36 male, mean age 47 years) were admitted during a 5-year period for injuries of the upper cervical spine. Sixty-five were followed for a mean time of 18 months. Three isolated ligamentous instabilities, 6 isolated C1 fractures, 3 complex C2 fractures, 10 combined C1/C2, and 48 C2 fractures (17 hangman's, 31 odontoid) were diagnosed. Twenty-nine patients were treated conservatively and for 41 patients surgery was the primary treatment. Twenty-three ventral odontoid screw fixations, 8 ventral platings and 10 dorsal stabilizations were performed. Stability was evaluated using flexion-extension radiography. Pain levels and neurological outcome were assessed.

RESULTS

Operative mortality and neurological morbidity were 0%. Two wound infections and 3 instabilities (17%) in odontoid Type II fractures primarily treated with ventral odontoid screw fixation needed dorsal restabilization. During follow-up examinations the neurological status of three patients was improved. In 62 patients preoperative status was attained. Six patients evaluated their pain as severe, two as disabling.

CONCLUSIONS

Candidates for surgery as the primary treatment include those with isolated ligamentous instabilities, Type III hangman's fractures and Type II odontoid fractures with dislocation more than 5 mm. In combined C1/C2 fractures the axis fracture dictates the treatment strategy. Patients who undergo dorsal procedures and have involvement of C1 have a greater chance of developing persistent pain.

C1-C2 transarticular screw fixation for treatment of C1-C2 instability

C1-C2 instability has traditionally been treated by C1-C2 posterior wiring and bone grafting. However, this technique has an incidence of non-union which may exceed 10%. Transarticular screw fixation has developed as a technique of providing increased strength of fixation of C1-C2 arthrodesis, while at the same time avoiding the need for postoperative halo bracing and avoiding the risk of neurological injury associated with the passage of sublaminar wires. We present a retrospective review of 12 patients with C1-C2 instability treated by C1-C2 transarticular screw fixation. Eight patients underwent this procedure as primary treatment, and 4 after a failed Gallie fusion. Five patients had a cruciate ligament rupture, 5 had an odontoid process fracture, 1 had os odontoideum, and 1 had rheumatoid instability. There was no surgical morbidity or mortality and, at a mean follow up of 12.1 +/- 3 months (range 8-14 months), all patients had achieved solid fusion, and all neurological symptoms referable to the instability had resolved. C1-C2 transarticular screw fixation has been shown to be safe and effective and has a number of advantages when compared to traditional posterior wiring techniques. We recommend that this technique be considered as a primary treatment of C1-C2 instability.

Atlantoaxial arthrodesis using Halifax interlaminar clamps reinforced by halo vest immobilization: a long-term follow-up experience

Thirty-two patients who underwent atlantoaxial arthrodesis using Halifax interlaminar clamps and halo vests between January 1989 and December 1992 were reviewed. The atlantoaxial instabilities were related to trauma in 16 patients, including 14 patients with unstable odontoid fractures, 1 patient with a complex C2 fracture, and 1 patient with a disrupted transverse ligament. Of the other 16 patients, whose atlantoaxial instabilities were nontraumatic in origin, 9 had instabilities that were secondary to rheumatoid arthritis, 1 had instability that was secondary to tuberculous infection, and 6 had instabilities that were caused by os odontoideum. The patients were followed postoperatively with lateral cervical radiographs for an average of 37 months (range, 16-59 mo). Solid atlantoaxial arthrodeses were achieved in all (100%) of these 32 patients after 32 to 111 days (average, 84.5 d) of halo immobilization, indicating atlantoaxial arthrodeses can be reasonably anticipated when Halifax interlaminar clamps with autogenous iliac bone grafting are reinforced by halo vest immobilization for 3 months.

C1-C2 posterior cervical fusion: long-term evaluation of results and efficacy

Posterior wiring techniques are the most commonly used methods of achieving C1-C2 arthrodesis. Recently, transarticular screw fixation and interlaminar clamping have been advocated to achieve more secure fixation. A retrospective review of patients undergoing C1-C2 fusion for nonneoplastic disease was undertaken at the University of Toronto Hospital, with the aim of determining the long-term outcome of the selected procedures. Thirty-two patients underwent 36 procedures from 1986 to 1992, with a mean follow-up of 4.7 +/- 2.2 years (range, 2.0-8.0 yr). The most common disease processes were odontoid fracture (18 patients), transverse atlantal ligament injury (5 patients), os odontoideum (5 patients), and rheumatoid C1-C2 instability (3 patients). Thirty-one Gallie fusions, one Brooks-Jenkins fusion, two transarticular screw fusions, and two Halifax clamp applications were performed. Six (19%) of Gallie/Brooks-Jenkins fusions failed. These occurred with os odontoideum (three patients), Type II odontoid fracture (two patients), and transverse atlantal ligament injury (one patient). All transarticular screw and Halifax clamp procedures resulted in successful fusions. Two procedures (6%) resulted in new neurological deficit; both of these patients underwent posterior wiring for os odontoideum. This study suggests that Type II odontoid fractures may be successfully managed by a posterior wiring technique alone. Rheumatoid C1-C2 instability may be managed by posterior wiring supplemented with halo immobilization. Transarticular screw fixation has several potential advantages as a technique for C1-C2 arthrodesis and, in particular, may be appropriate for os odontoideum that had a high failure rate (75%) with conventional posterior wiring, even when this was supplemented with halo bracing.

C1-C2 posterior cervical fusion: long-term evaluation of results and efficacy

Posterior wiring techniques are the most commonly used methods of achieving C1-C2 arthrodesis. Recently, transarticular screw fixation and interlaminar clamping have been advocated to achieve more secure fixation. A retrospective review of patients undergoing C1-C2 fusion for nonneoplastic disease was undertaken at the University of Toronto Hospital, with the aim of determining the long-term outcome of the selected procedures. Thirty-two patients underwent 36 procedures from 1986 to 1992, with a mean follow-up of 4.7 +/- 2.2 years (range, 2.0-8.0 yr). The most common disease processes were odontoid fracture (18 patients), transverse atlantal ligament injury (5 patients), os odontoideum (5 patients), and rheumatoid C1-C2 instability (3 patients). Thirty-one Gallie fusions, one Brooks-Jenkins fusion, two transarticular screw fusions, and two Halifax clamp applications were performed. Six (19%) of Gallie/Brooks-Jenkins fusions failed. These occurred with os odontoideum (three patients), Type II odontoid fracture (two patients), and transverse atlantal ligament injury (one patient). All transarticular screw and Halifax clamp procedures resulted in successful fusions. Two procedures (6%) resulted in new neurological deficit; both of these patients underwent posterior wiring for os odontoideum. This study suggests that Type II odontoid fractures may be successfully managed by a posterior wiring technique alone. Rheumatoid C1-C2 instability may be managed by posterior wiring supplemented with halo immobilization. Transarticular screw fixation has several potential advantages as a technique for C1-C2 arthrodesis and, in particular, may be appropriate for os odontoideum that had a high failure rate (75%) with conventional posterior wiring, even when this was supplemented with halo bracing.