Atlantoaxial rotatory fixation in the setting of associated congenital malformations: a modified classification system

Klippel-Feil Syndrome Associated with Renal and Cardiac Anomalies in an Infant: A Case Report

Klippel-Feil syndrome is a rare congenital bone disorder characterised by a triad of short neck, low posterior hairline and limited lateral bending of the neck with an annual incidence of 1 in 40,000 live births. It has remained an obscure term in the medical literature because of its variability in presentation and wide spectrum of anomalies involving multiple organ systems. It is unusual to find a case that has all three classical triad features. Here, we present a case of a 9-month-old infant who manifests not only all three classical triad features associated with Klippel-Feil syndrome but also demonstrates the presence of congenital heart disease, scoliosis, and renal ectopia. An early comprehensive evaluation of a suspected case is essential for diagnosis and counselling which impacts its prognosis, helps minimize social stigma and affords parents the opportunity to consider cosmetic surgery as an option, should they choose to pursue it.

Keywords

case reports; congenital; heart diseases; Klippel-Feil syndrome; scoliosis.

Successful Closed Reduction of Atlantoaxial Rotatory Fixation in Children-A Retrospective Study of 30 Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To review our treatment experience and to investigate the process of this disease.

METHODS

Clinical data of AARF patients, who received closed reduction, was retrospectively reviewed. Patients were divided into 2 groups according to the length of delay (Group I: 1 month ≤ delayed time < 3 months), Group II (delayed time < 1 months). The correlation between the length of delayed time and clinical recovery (CR), radiological recovery (RR), and total recovery time were measured. The atlantodental interval (ADI), lateral mass-dens interval (LDI) and lateral joint space (LJS) were compared at admission and final follow-up.

RESULTS

30 children (12 girls and 18 boys) with AARF had received conservative treatment. The mean age at initial treatment was 8.13-year-old, ranging from 5 to 14. The mean follow-up time was 26.93 months (range, 6-87 months). The average length of delayed time was 28.53 days (range, 2-80 days). When the LDI, LJS, and ADI differences are compared at admission and the final visit, the differences are reduced significantly on LDI and LJS. A positive correlation is observed between the length of the delay and CR time and total recovery time (r = 0.63, p = 0.00 and r = 0.47, p = 0.01) respectively.

CONCLUSIONS

Pediatric AARF patients who have a delay time < 3 months can be treated with closed reduction successfully. The longer the delayed time, the longer the traction time, but the cervical collar time is almost the same. The LDI and LJS on the anteroposterior of X-rays are convenient to estimate the progress of this condition during the treatment.

C1-C2 Rotatory Subluxation in Adults “A Narrative Review”

The atlantoaxial joint C2 (axis) with the anterior arch of C1 (atlas) allows 50% of cervical lateral rotation. It is responsible for precise and important movements that allow us to perform precise actions, both in normal and working life. Due to low incidence in adults, this condition often goes undiagnosed, or the diagnosis is delayed and the outcome is worse. An early diagnosis and treatment are essential to ensure satisfactory neurological and functional outcomes. The aim of this review is to analyze C1-C2 rotatory subluxation in adults, given its rarity. The time between injury and reduction is key, as it is directly related to prognosis and the severity of the treatment options. Due to low incidence in adults, this condition often goes undiagnosed, or the diagnosis is delayed as a lot of cases are not related to a clear trauma, with a poor prognosis just because of the late diagnosis and the outcome is worse. The correct approach and treatment of atlantoaxial dislocation requires a careful study of the radiological findings to decide the direction and plane of the dislocation, and the search for associated skeletal anomalies.

Prevalence and Risk Factors of Surgical Treatment for Klippel–Feil Syndrome

Background

Recently, there have been some reports on surgical treatment for Klippel–Feil syndrome, but the prevalence and risk factors of surgery have not been well evaluated. This study sought to find the prevalence and potential risk factors of surgical treatment.

Methods

A retrospective radiographic review of 718 Klippel–Feil syndrome patients seen at Peking University Third Hospital from January 2010 to October 2017 was performed. Parameters included age, gender, deformity, cervical instability, Samartzis classification, and surgical treatment. Based on the surgical treatment they received, patients were divided into a surgery group and a non-surgery group. Prevalence and possible risk factors of surgical treatment were assessed.

Results

A total of 718 Klippel–Feil syndrome patients, including 327 men and 391 women, with an average age of 46.8 years were enrolled. According to the Samartzis classification scheme, 621 cases (86.5%) were classified as type I, 48 cases (6.7%) were classified as type II, and 49 cases (6.8%) were classified as type III, respectively. The most commonly fused segments were C2–3 (54.9%) and C5–6 (9.3%). Of all 718 patients, 133 (18.5%) patients underwent surgical treatment, mainly via the posterior approach (69.9%). The clinical factors included age, gender, deformity, instability, and Samartzis classification. Men were more likely to require surgical treatment (p < 0.001). Patients with instability (p < 0.001) or patients with deformity (p = 0.004) were also more likely to undergo surgery. All three of these variables were included in the binary regression analysis. Finally, gender (p < 0.001) and unstable joints (p < 0.001) were identified to be independently associated with surgical treatment. Gender was the most important risk factor with men being 2.39 times more likely to have surgical treatment, while patients with instability were 2.31 times more likely to receive surgery.

Conclusion

The prevalence of patients with Klippel–Feil syndrome requiring surgery was 18.5%, with the majority undergoing posterior cervical surgery. Gender and instability were indemnified as independent risk factors leading to surgical treatment.

Role of Atlas Assimilation in the Context of Craniocervical Junction Anomalies

Atlas assimilation (AA) may be associated with atlantoaxial dislocation, Chiari malformation (CM), and basilar invagination. The importance of AA in the context of craniocervical junction (CVJ) anomalies is unclear. Considering this context, this study's objective is to discuss the role of AA in the management of CVJ anomalies, especially in CM. A comprehensive literature review was performed. In addition, some illustrative cases were discussed on the basis of our review. Finally, we propose a theoretic algorithm to evaluate patients with AA and CM. AA is a proatlas segmentation anomaly that may be complete or incomplete. It may be totally asymptomatic or symptomatic as the result of transferred shifted forces onto the C1-2 joints, leading to clear instability (atlantoaxial dislocation) or mild C1-2 instability. Cautious surgical planning may be required due to associated vertebral artery anomalies. AA with concomitant C2-C3 segmentation failure is highly associated with late C1-C2 instability. CVJ decompression failure was reported in patients with CM and a low clivus canal angle (<130-135 degrees). Patients with assimilated anterior C1 arches usually have evident AAD. CM patients with AA generally have type 1 BI or type 2 BI and are reported with higher rates of CVJ instabilities when compared with those "pure" CM. Dynamic examinations may provide additional evidence of atlantoaxial instability. Although AA per se is not considered an unstable configuration, further and detailed evaluations of patients with CM associated with AA are necessary. Some associated unstable configurations required concomitant CVJ fixation.

Cervical vertebral malformations in 9 dogs: radiological findings, treatment options and outcomes

BACKGROUND

Disregarding atlantoaxial instability in toy breed dogs associated with dens malformation and cervical spondylomyelopathy; cervical vertebral malformations are rare and poorly characterised in veterinary medicine and consequently treatment strategies and clinical outcome are sparsely documented.

RESULTS

Electronic clinical records at our veterinary referral hospital between April 2009 and November 2018 were searched for patients presented with cervical myelopathy secondary to an underlying suspected vertebral malformation/instability. Nine dogs met the inclusion criteria. Two dogs were diagnosed with atlantoaxial pseudoarthrosis, two dogs with a syndrome similar to Klippel-Feil in humans, two dogs with congenital cervical fusion, two dogs with congenital C2-C3 canal stenosis and deficiencies of the dorsal arch of the atlas and laminae of the axis and one with axial rotatory displacement. Tetraparesis, proprioceptive deficits, cervical hyperesthesia and cervical scoliosis were the most common clinical signs. The axis was the most commonly affected vertebrae (8/9 patients). Patients diagnosed with Klippel-Feil-like Syndrome were the younger (average of 262.5 days) and patients diagnosed with fused vertebrae the oldest (average of 2896 days) in our studied population (average of 1580.8 days).

CONCLUSION

Cervical vertebral malformations are rare, or alternatively, being underdiagnosed in veterinary medicine. Patients diagnosed with Klippel-Feil-like Syndrome had a successful medium and long-term outcome with conservative management. Surgical treatment was often indicated for the other conditions presented in this study due to spinal instability and/or myelopathy. Stabilisations via ventral approaches were revealed to be safe. Multicentre and prospective studies are necessary in veterinary medicine to better characterise clinical outcomes in cervical vertebral malformations.

Fractures of the Bilateral C2 Neurocentral and Lateral Dental Synchondroses with Kyphotic C1-C2 Subluxation in a 3-Year-Old Girl: A Description of a Rare Fracture Pattern and Its Treatment: A Case Report

CASE

Spinal fractures are rare in young children. Because spinal anatomy and biomechanics differ in children and adults, knowledge of the deviations of the juvenile spine is necessary for adequate treatment. We present the case of a young girl with an unusual C2 fracture that included rupture of both of the neurocentral and lateral dental synchondroses, with an opening of the synchondroses and a caudal dislocation of both vertebral arches following a head-on motor vehicle collision. The whole body and apex of the dens was displaced anteriorly and cranially with a kyphotic angulation of 34°. We describe the treatment and clinical and radiographic outcome after 1 year.

CONCLUSION

Using passive hyperextension and distraction of the head, a closed open-mouth digital reduction was performed under continuous fluoroscopy. At the 1-year follow-up, the patient had full range of motion of the head without pain or neurologic dysfunction.

"Clinical triad" findings in pediatric Klippel-Feil patients

BACKGROUND

It has been propagated that patients with Klippel-Feil syndrome (KFS) exhibit "clinical triad" findings (CTFs), known as a short neck, low posterior hairline, and limited cervical range of motion (ROM). However, the literature has noted that up to 50 % of KFS cases may not present with such findings and the reasoning behind such assertions remains speculative. As such, the following study addressed the association between CTFs to that of congenitally-fused cervical segments and other risk factors in KFS patients.

METHODS

We conducted a retrospective clinical study based on prospectively collected radiographic data. Thirty-one KFS patients at a single institution were assessed. Radiographs were used to evaluate the location and extent of congenitally-fused segments (spanning the occiput (O) to the first thoracic vertebra (T1)), as well as examining coronal and sagittal cervical alignments based on the Samartzis et al. KFS classification. Clinical records were evaluated to account for the initial clinical assessment of CTFs. Patients were further stratified into two groups: Group 1 included patients noted to have any CTFs, while Group 2 included patients who had no such findings.

RESULTS

There were 12 males and 19 females (mean age at initial consultation: 9.7 years). No evidence of any of the CTFs was shown in 35.5 % of patients, whereas 38.7, 16.2 and 9.7 % were determined to have one, two or all three criteria, respectively. Limited cervical ROM was the most common finding (64.5 % of patients). In Group 1, 25 % had a short neck, 30 % a low posterior hairline, and 100 % exhibited limited cervical ROM. Group 1 had a mean of 3.9 fused cervical segments, whereas Group 2 had a mean of 2.5 fused cervical segments (p = 0.028). Age, sex-type, occipitalization and alignment parameters did not significantly differ to Group-type (p > 0.05). In Group 1, based on the Samartzis et al. Types I, II, and III, 16.7, 73.3, and 80.0 % of the patients, respectively, had at least one CTF.

CONCLUSIONS

Complete CTFs were not highly associated during the clinical assessment of young KFS patients. However, KFS patients with extensive, congenitally-fused segments (i.e. Samartzis et al. Type III) were significantly more likely to exhibit one of the components of the CTF, which was predominantly a limited cervical ROM. Clinicians managing young pediatric patients should not rely on the full spectrum of CTFs and should maintain a high-index of suspicion for KFS, in particular in individuals that exhibit associated spinal findings, such as congenital scoliosis.

Atlantoaxial rotatory subluxation in children

Atlantoaxial rotatory subluxation is a rare condition in which patients present with the acute onset of torticollis. Atlantoaxial rotatory subluxation represents a spectrum of disease from muscle spasm to a fixed mechanical block to reduction of the atlantoaxial complex. If left untreated, some cases may resolve spontaneously; however, other cases may result in the development of secondary changes in the bony anatomy of the atlantoaxial joint, leading to persistent deformity. Diagnosis of the condition is largely clinical but can be aided by various imaging modalities, including radiographs, dynamic CT scanning, three-dimensional CT reconstructions, or MRI. Consideration should always be given to infection or other inflammatory disease as an underlying, precipitating cause. Treatments include observation, the use a cervical collar and analgesics, halter or skeletal traction, and posterior fusion of C1-C2. The most important factor for success of conservative treatment is the time from the onset of symptoms to recognition and the initiation of treatment.

The surgical management of atlanto-axial subluxation in juvenile rheumatoid arthritis

Juvenile idiopathic arthritis (JIA) is a chronic condition affecting patients <16 years of age and can be associated with substantial morbidity. Atlanto-axial subluxation (AAS) is a known complication of JIA and can result in pain, reduced neck motion and neurological compromise. In this paper, we present the case of a 10-year old suffering with JIA and significant AAS; we discuss the management options and present the approach and outcome of treatment for this case.

Odontoid synchondrosis fracture treated by c1-2 polyaxial screw-rod fixation

The synchondrosis between the dens and the body of axis normally fuses between 5 and 7 years of age. Until this age, synchondrosis fractures can occur in children. Most synchondrosis fractures are conventionally treated by external immobilization alone. We report a 10-year-old child with odontoid synchondrosis fracture who was treated by C1 lateral mass and C2 pars screw rod fixation with a successful outcome and discuss the possible reasons for occurrence of odontoid synchondrosis fracture in this older child as well as the indications for surgery in this condition.

Stratified whole genome linkage analysis of Chiari type I malformation implicates known Klippel-Feil syndrome genes as putative disease candidates

Chiari Type I Malformation (CMI) is characterized by displacement of the cerebellar tonsils below the base of the skull, resulting in significant neurologic morbidity. Although multiple lines of evidence support a genetic contribution to disease, no genes have been identified. We therefore conducted the largest whole genome linkage screen to date using 367 individuals from 66 families with at least two individuals presenting with nonsyndromic CMI with or without syringomyelia. Initial findings across all 66 families showed minimal evidence for linkage due to suspected genetic heterogeneity. In order to improve power to localize susceptibility genes, stratified linkage analyses were performed using clinical criteria to differentiate families based on etiologic factors. Families were stratified on the presence or absence of clinical features associated with connective tissue disorders (CTDs) since CMI and CTDs frequently co-occur and it has been proposed that CMI patients with CTDs represent a distinct class of patients with a different underlying disease mechanism. Stratified linkage analyses resulted in a marked increase in evidence of linkage to multiple genomic regions consistent with reduced genetic heterogeneity. Of particular interest were two regions (Chr8, Max LOD = 3.04; Chr12, Max LOD = 2.09) identified within the subset of "CTD-negative" families, both of which harbor growth differentiation factors (GDF6, GDF3) implicated in the development of Klippel-Feil syndrome (KFS). Interestingly, roughly 3-5% of CMI patients are diagnosed with KFS. In order to investigate the possibility that CMI and KFS are allelic, GDF3 and GDF6 were sequenced leading to the identification of a previously known KFS missense mutation and potential regulatory variants in GDF6. This study has demonstrated the value of reducing genetic heterogeneity by clinical stratification implicating several convincing biological candidates and further supporting the hypothesis that multiple, distinct mechanisms are responsible for CMI.

Cervical myelopathy caused by atlantoaxial instability in a patient with an os odontoideum and total aplasia of the posterior arch of the atlas: a case report

Introduction

Congenital hypoplasia of the atlas has rarely been reported. Myelopathy caused by the complete absence of the posterior arch of the atlas has not been reported. This case report describes the diagnosis and successful treatment of a myelopathy due to the complete absence of the posterior arch of the atlas.

Case presentation

A 59-year-old Japanese man experienced pain in his nuchal region with progressive spasticity, numbness and hypesthesia in his upper and lower limbs. Deep tendon reflexes in his upper and lower limbs were increased. The complete absence of the posterior arch of the atlas and atlantoaxial instability were found in a roentgenogram. Magnetic resonance imaging detected high signal intensity on T2-weighted images in his spinal cord at the level of cervical vertebrae 1 to 2. Our patient underwent posterior occipito-C4 fixation with pedicle screws. After the operation, the pain in his nuchal region disappeared and his symptoms of myelopathy improved. Only slight numbness of his upper limbs remained.

Conclusions

This is the first report of myelopathy due to the complete absence of the posterior arch of the atlas.

Rotatory subluxation: experience from the Hospital for Sick Children

OBJECT

Diagnosis and management of atlantoaxial rotatory subluxation (AARS) is challenging because of its variability in clinical presentation. Although several treatment modalities have been employed, there remains no consensus on the most appropriate therapy. The authors explore this issue in their 9-year series on AARS.

METHODS

Records of patients diagnosed radiologically and clinically with AARS between May 2001 and March 2010 were retrospectively reviewed. Of 40 patients identified, 24 were male and were on average 8.5 years of age (range 15 months-16 years). Causes of AARS included trauma, congenital abnormalities, juvenile rheumatoid arthritis, infection, postsurgical event, and cryptogenic disease. Four patients had dual etiologies. Symptom duration varied: 29 patients had symptoms for less than 4 weeks, 5 patients had symptoms between 1 and 3 months, and 6 patients had symptoms for 3 months or more.

RESULTS

Treatment with a cervical collar was sufficient in 21 patients. In 1 patient collar management failed and halter traction was used to reduce the subluxation. Seven patients underwent initial halter traction, but in 4 the subluxation progressed and the patients required halo traction. A halo vest was placed in 2 patients on presentation because the rotatory subluxation was severe; both patients required subsequent operative fusion. One patient required decompression and fusion due to severe canal compromise and myelopathy. All patients requiring fusion presented with subacute symptoms.

CONCLUSIONS

Management of AARS varies due to the spectrum of clinical presentations. Patients presenting acutely without neurological deficits can likely undergo collar therapy; those in whom the subluxation cannot be reduced or who present with a neurological deficit may require traction and/or surgical fixation. Patients presenting subacutely may be more prone to requiring operative intervention.