Atlantoaxial Joint Distraction Research Articles

Surgical treatment strategy for difficult-reducible atlantoaxial dislocation

Objective: To discuss the surgical strategy for difficult-reducible atlantoaxial dislocation. Methods: Clinical data of 82 patients with difficult-reducible atlantoaxial dislocation underwent surgical treatment in the Department of Neurosurgery, Xuanwu Hospital from January 2018 to February 2019 were retrospectively reviewed. Total of 32 men and 50 women were included, with a mean age of (41.8±12.9) years. Most cases (n=80) were treated with one-staged posterior atlantoaxial joint distraction and cage implantation, a few (n=2) underwent ventral decompression. All cases were followed up, postoperative improvement of clinical symptoms and radiology parameters were analyzed. Results: Of the patients, 80 cases (97.6%) received one-staged posterior atlantoaxial joint distraction and cage implantation; lateral facet joint bony fusion was found in 4 patients and was cut off with an osteotome. Transoral odontoidectomy was performed in 2 cases (2.4%) with fused atlanto-odontoid joint. All the patients were followed-up for (18.6±7.3) months. Postoperative CT showed complete reduction of ADI was achieved in 60 patients (75.0%). The ADI decreased significantly after the operation [(2.1±1.4) mm vs (5.0±1.5) mm, P<0.05]. The postoperative vertical distance between odontoid process and the Chamberlain line decreased significantly when compared with that before the operation [(3.9±3.8) mm vs (10.2±5.2) mm, P<0.05]. The mean JOA score at 6 months post operation improved significantly than that before the operation (13.7±1.5 vs 11.2±1.7, P<0.05). Seventy-five patients (93.8%) had atlantoaxial intra-articular bony fusion at 1 year follow-up. Conclusion: Most difficult-reducible atlantoaxial dislocations can be managed well by posterior one-staged atlantoaxial joint distraction and Cage implantation.

Atlantoaxial Joint Distraction and Fusion with DTRAX Intra-Articular Cages: A Cadaveric Feasibility Study and Review of the Pertinent Literature

Atlantoaxial joint distraction is a key procedure for the treatment of selected patients affected by basilar invagination (BI). In recent years, several authors have reported various techniques of distraction and fixation of the C1-C2 joint using different types of intra-articular spacers, with or without posterior fixation. We review the pertinent literature and propose a feasibility study on the use of a new device for the distraction of the C1-C2 joint aimed to the descent of the dens out of the foramen magnum suggesting its application on selected cases of BI. The GL-DTRAX Cervical Cage-SE is a cage approved by the Food and Drug Administration for distraction and fixation of subaxial cervical spine. Five adult cadaveric specimens were dissected surgically to evaluate the feasibility of DTRAX insertion inside the C1-C2 joint through a posterior approach. The cages were uneventfully set into the C1-C2 intra-articular space of all samples without the need to sacrifice C2 nerve roots and ganglia. Postoperative cervical computed tomography scanning confirmed the correct fitting of the devices in every sample. This cadaveric study highlights the feasibility of the DTRAX cage as a C1-C2 intra-articular device producing a substantial distraction of atlantoaxial complex and suggesting a possible therapeutic role in selected cases of BI.

Does fracture-extension into the pars interarticularis alter outcomes in odontoid failure? a technical note on pars interarticularis osteotomy and atlantoaxial distraction arthrodesis.

Odontoid process fractures can extend rostral into the C2 arch. We investigated the clinical impact of a concurrent fracture of the pars interarticularis on odontoid failure. To overcome the surgical challenges related to the morphology of these fractures, we describe a novel surgical strategy using atlantoaxial joint distraction arthrodesis. We conducted a single centre cohort study of 13 consecutive patients with odontoid fractures extending into the pars treated between June 2016 and June 2018. Criteria for a stable fibrous non-union were: Atlanto-Dens Interval (ADI) < 3mm, Posterior Atlanto-Dens Interval (PADI) > 14mm and lack of symptomatic motion at the fracture site. Atlantoaxial instability was defined as greater than 50% subluxation across the C1-C2 joint. Return to pre-injury performance status was considered a satisfactory clinical outcome. The mean age of the patient population was 77.2years (SD 11.9). The mean follow-up time was 15months (SD 5.2). 69% had an associated atlantoaxial instability (P-value 0.0005). Cervical orthosis treatment was associated with a high non-union rate (70%) (P-value 0.04) although it did not affect the overall clinical outcome. 2 cases presented with cord compression were treated surgically with pars interarticularis osteotomy and atlantoaxial distraction arthrodesis. Odontoid fracture with extension into the pars interarticularis often present with atlantoaxial instability and may result in stable fibrous non-union if treated non-operatively. The C1-C2 segment can be stabilised with atlantoaxial distraction arthrodesis achieved through an osteotomy of the pars interarticularis.

Atlantoaxial Joint Distraction for the Treatment of Basilar Invagination: Clinical Outcomes and Radiographic Evaluation.

To investigate the causes of partial remission in patients with basilar invagination (BI) and irreducible atlantoaxial dislocation (IAAD) treated with transoral atlantoaxial reduction plate (TARP) without odontoidectomy and quantify the distance of odontoid descent. Between August 2010 and July 2012, 22 consecutive patients with BI with IAAD who underwent TARP surgery were reviewed. The preoperative and postoperative radiographic parameters were evaluated. Follow-up data and the symptom treatment interval (STI), defined as the interval between the onset of symptoms and surgical treatment, were assessed. Neurological function was evaluated as neurologic improvement, defined as ([Postoperative Japanese Orthopedic Association (JOA) score]- [Preoperative JOA score])/(17- [Preoperative JOA score]). The patients were assigned to group A (<50%) or group B (≥50%) based on their level of neurologic improvement. All 22 patients improved clinically to varying degrees. The mean preoperative STI was 105.6 ± 67.6 months for group A and 45.3 ± 46.7 months for group B (P<0.05). There were no significant between-group differences in follow-up (P > 0.05) or with respect to radiographic parameters (P > 0.05). Persistent brainstem compression was observed in 1 patient, whose symptoms were not adequately relieved after revision surgery (transoral odontoidectomy and posterior decompression and fusion). No fixation failure was observed. Descent of the odontoid process is useful for treating basilar invagination. TARP surgery without odontoidectomy may pull the dens caudally and ventrally to achieve sufficient decompression of the spinal cord. Neurologic improvement may be associated with STI.

Atlantoaxial Joint Distraction with a New Expandable Device for the Treatment of Basilar Invagination with Preservation of the C2 Nerve Root: A Cadaveric Anatomical Study.

Atlantoaxial joint distraction has been advocated for the decompression of the brain stem in patients affected by basilar invagination, avoiding direct transoral decompression. This technique requires C2 ganglion resection and it is often impossible to perform due to the peculiar bony anatomy. We describe a cadaveric anatomical study supporting the feasibility of C1-C2 distraction performed with an expandable device, allowing easier insertion of the tool and preservation of the C2 nerve root. In five adult cadaveric specimens, posterior atlantoaxial surgical exposure was performed and an expandable system was inserted within the C1-C2 joint. The expansion of the device, leading to active distraction of the joint space, together with all the surgical steps of the technique was recorded with anatomical pictures and the final results were checked with a computed tomography (CT) scan. Insertion of the device was easily performed in all cases without anatomical conflict with the C2 ganglion; CT scans confirmed the distraction of the C1-C2 joint. This cadaveric anatomical study confirms the feasibility of the introduction of an expandable and flexible device within the C1-C2 joint, allowing it's distraction and preservation of the C2 ganglion.

Anterior facetal realignment and distraction for atlanto-axial subluxation with basilar invagination …. a technical note

Unilateral anterior retropharyngeal approach was used in a case of basilar invagination with atlanto-axial instability. This approach provided easy access to both atlanto-axial joints. Wedge-shaped titanium cages were used to distract the joints and reduce the basilar invagination. Titanium plates with screws were used to fix the lateral mass of atlas with the body of axis, bilaterally. The anterior atlanto-axial joint distraction procedure has not been described in literature before seems to be an easy option in selected cases of craniovertebral anomalies and needs to be investigated by more surgeons.

Single-stage anterior release and posterior instrumented fusion for irreducible atlantoaxial dislocation with basilar invagination

Background ContextThe options available for treatment of irreducible atlantoaxial dislocation (IAAD) with basilar invagination are odontoidectomy, posterior decompression, and posterior atlantoaxial joint distraction. In 2006, Wang et al. described that most IAAD can be reduced following anterior release of contracted soft tissues. Anterior release may be done by transoral (TO) or retropharyngeal (RP) approach. Posterior instrumented fusion provides stability and helps in achieving further reduction. PurposeThis study aimed to study the neurologic and radiological outcome following treatment of basilar invagination associated with IAAD by anterior release and posterior instrumented fusion. Study DesignA retrospective case series was carried out. Patient SampleThe patient sample comprised 19 patients with IAAD. Outcome MeasurePatients were assessed for neurologic recovery by Benzel modified Japanese Orthopaedic Association (mJOA) score and radiologically by assessing reduction on lateral radiographs and comparing clivus-canal angle (CCA) on preoperative and postoperative computed tomography scan. MethodsNineteen consecutive patients with IAAD were surgically treated. Anterior release was done via TO approach in 12 patients and RP approach in 7. Following anterior release, all patients underwent posterior instrumented fusion. ResultsThis study included 15 men and 4 women with mean follow-up of 18 months. Pathology included occipitalization of atlas in 16 patients, os odontoideum in 2, and missing posterior elements of axis in 1. All patients had cervical myelopathy. Occipitocervical fixation was done in 18 patients and C1–C2 transarticular screw fixation in 1. Fifteen patients had anatomical reduction whereas four had partial reduction. The CCA improved from a mean preoperative angle of 111.47° to mean postoperative angle of 142.84°. The mJOA improved from preoperative mean mJOA of 12.89 to a postoperative mean mJOA of 16.84. Fusion was achieved in all patients. Maceration of posterior wound which healed by daily cleaning and dressing was noted in three patients. Implant breakage on one side was noted in 1 patient at 3 months post operation; however, the patient remained asymptomatic. ConclusionThis series reinforces the safety and efficacy of both TO and RP anterior release for reduction of IAAD. Posterior fixation helps in achieving further reduction and provides stability. Anterior release followed by instrumented posterior fusion is a safe and effective modality of treatment for IAAD associated with basilar invagination.

Treatment of basilar invagination with atlantoaxial dislocation: atlantoaxial joint distraction and fixation with transoral atlantoaxial reduction plate (TARP) without odontoidectomy.

Although direct transoral decompression and one-stage posterior instrumentation can obtain satisfactory cord decompression for the treatment of basilar invagination with atlantoaxial dislocation, surgical injuries run high as combinative anterior-posterior approaches were necessary. Furthermore, the complications will rise notably when involvement of dens and/or clivus in the decompression necessitates relatively complicated surgical techniques. First initiated in 2005, transoral atlantoaxial reduction plate (TARP) works as an internal fixation for the treatment of basilar invagination with irreducible atlantoaxial dislocation. Therefore, this article aimed to describe several operative experiences about this approach, which has delivered successful decompression, fixation and fusion. 21 consecutive patients with basilar invagination underwent the TARP operation. The pre- and postoperative medulla-cervical angles were measured and compared. The JOA scores of spinal cord function were calculated pre- and post-operatively. 20 cases (20/21) were followed up to average 12.5 months. Symptoms of all the 20 cases were relieved in different degrees. The postoperative imaging showed the odontoid processes obtained ideal reduction and the internal fixators were all in good position. The medulla-cervical angle was correctd from an average (± standard deviation) 128.7° + 11.9° (n = 20) before surgery to 156.5° + 8.1° (n = 20) after surgery (P < 0.01). The average preoperative and postoperative Japaneses Orthopedic Association scores were 11.25 (n = 20) and 15.9 (n = 20), respectively, indicating 76 % improvement. Screw-loosening was observed in one patient due to severe osteoporosis. After a revised operation with a TARP in another size, the neurological symptoms showed no obvious improvements. Then the treatment was terminated. The TARP operation and intra-operative traction could reduce the odontoid process superiorly migrating into the foramen magnum, directly ease the ventral compression of spinal cord, and fix the reduced atlantoaxial joints through a single transoral approach without the need of a posterior operation. In this stury, 21 patients were evaluated and 20 did well with TARP operation. The preliminary clinical result was satisfactory.

Atlantoaxial joint distraction as a treatment for basilar invagination: A report of an experience with 11 cases

A novel method of treatment of basilar invagination that involves distraction of the atlantoaxial joint using specially designed spiked spacers is described. Bone graft that is additionally placed within the appropriately prepared atlantoaxial joint and posterior to the arch of atlas and lamina of C2 provides bony fusion. Between December 2002 and April 2007, 11 patients underwent the discussed method of fixation at the Department of Neurosurgery, King Edward Memorial Hospital in Mumbai, India. All 11 patients had "congenital" basilar invagination and the symptoms were progressive in nature. The mean follow-up period was 21 months (range 8-40 months). Neurological improvement and successful distraction with atlantoaxial stabilization and ultimate bone fusion was achieved in all the patients and was documented with dynamic radiography. There were no neurological, vascular, or infective complications. We conclude that the described method of atlantoaxial joint distraction and fixation provides an alternative treatment strategy for cases with basilar invagination. "Joint distraction" as a stand-alone method could provide reduction of basilar invagination and firm stabilization in such cases.

One stage reduction and fixation for atlantoaxial spondyloptosis: report of four cases

We report four patients having an extremely rare and hitherto unreported clinical condition of spondyloptosis of the atlas over axis. Between the year 1999 and 2004, four patients with spondyloptosis were retrospectively analysed. The age of the patients ranged from 12 to 31 years. In three patients, the aetiology of spondyloptosis was probably congenital in nature and in one case it was secondary to rheumatoid disease. The patients presented with varying degrees of neck pain and spastic quadriparesis. All patients were successfully treated by atlantoaxial joint distraction, reduction of the dislocation and direct lateral mass plate and screw fixation by techniques described earlier by the senior author. Manipulation of the atlantoaxial joints and restoring the anatomical craniovertebral alignments is possible and probably an ideal treatment of cases with atlantoaxial spondyloptosis.

Progressive Basilar Invagination After Transoral Odontoidectomy: Treatment by Atlantoaxial Facet Distraction and Craniovertebral Realignment

The issue of progression of congenital basilar invagination is evaluated on the basis of 3 clinical cases. The rationale of treatment of basilar invagination in general and, particularly, in the complex clinical situation encountered in the presented cases, by the authors' technique of atlantoaxial joint distraction, reduction of basilar invagination, and direct lateral mass plate and screw fixation is discussed. The subject of progression of congenital basilar invagination and recurrent craniocervical cord compression after an initial transoral decompression is analyzed, and an alternative surgical treatment involving craniovertebral bone realignment is suggested. This is a review of 3 cases of basilar invagination treated earlier by transoral decompression. No fixation procedure was performed. The patients presented with recurrent symptoms of high cervical cord compression. Investigations revealed a progression of basilar invagination and cord compression. The treatment of such a complex clinical situation by atlantoaxial joint distraction is discussed. Between September 2001 and January 2004, we treated 3 patients with congenital basilar invagination who underwent transoral odontoidectomy but did not undergo any posterior atlantoaxial or occipitoaxial fixation. The patients had postoperative improvement but worsening of their neurologic condition after an average duration of 26 months after transoral surgery. Repeat investigations revealed that basilar invagination and the craniovertebral alignments worsened during the period, and there was recurrent cervicomedullary cord compression. These patients were treated by atlantoaxial facet distraction, and attempts were made toward reduction of the basilar invagination and craniovertebral junction bony realignment, and atlantoaxial fixation by the technique recently described by us. During the average follow-up of 25 months, all 3 patients have had a neurologic recovery. The probable cause of basilar invagination and its progression is a congenital malformation ofalignment of the facets of the atlantoaxial joint. Distraction of the facets and direct interarticular atlantoaxial fixation presents a unique opportunity of reduction of the basilar invagination and fixation of the region.

Atlanto-axial Joint Distraction in the Treatment of Select Cases of Basilar Invagination, Syringomyelia and Fixed Atlanto-axial Dislocation

Not available.Nepal Journal of Neuroscience, Volume 2, Number 1, 2005, page: 1-6

Atlantoaxial joint distraction for treatment of basilar invagination secondary to rheumatoid arthritis

We present our experience of treating two cases of rheumatoid arthritis involving the craniovertebral junction and having marked basilar invagination by an alternative treatment method. In both the cases, the facets were osteoporotic and were not suitable for screw implantation. The patients were 66 and 72 years of age and both patients were females. Both the patients presented with complaints of progressively increasing spastic quadriparesis. Surgery involved attempts to reduce the basilar invagination and restore the height of the 'collapsed' lateral mass by manual distraction of the facets of the atlas and axis and forced impaction of titanium spacers in the joint in addition to bone graft harvested from the iliac crest. The procedure also provided stabilization of the region. No other fixation procedure involving wires, screws, plate and rods was carried out simultaneously. Following surgery both the patients showed symptomatic improvement and partial restoration of craniovertebral alignments. Follow-up is of 2 and 24 months. Distraction of the facets of atlas and axis and impaction of metal implant and bone graft in the facet joint can assist in reduction of basilar invagination and fixation of the region in selected cases of rheumatoid arthritis involving the craniovertebral junction.

Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation.

The author discusses the successful preliminary experience of treating selected cases of basilar invagination by performing atlantoaxial joint distraction, reduction of the basilar invagination, and direct lateral mass atlantoaxial plate/screw fixation. Twenty-two patients with basilar invagination-in which the odontoid process invaginated into the foramen magnum and the tip of the odontoid process was above the Chamberlain, McRae foramen magnum, and Wackenheim clival lines-were selected to undergo surgery. In all patients fixed atlantoaxial dislocations were documented. The 16 male and six female patients ranged in age from 8 to 50 years. A history of trauma prior to the onset of symptoms was documented in 17 patients. Following surgery, the author observed minimal-to-significant reduction of basilar invagination and alteration in other craniospinal parameters resulting in restoration of alignment of the tip of the odontoid process and the clivus and the entire craniovertebral junction in all patients. In addition to neurological and radiological improvement, preoperative symptoms of torticollis resolved significantly in all patients. The minimum follow-up period was 12 months and the mean was 28 months. Joint distraction and firm lateral mass fixation in selected cases of basilar invagination is a reasonable surgical treatment for reducing the basilar invagination, restoring craniospinal alignment, and establishing fixation of the atlantoaxial joint.