Remodeling of C2 facet deformity prevents recurrent subluxation in patients with chronic atlantoaxial rotatory fixation: a novel strategy for treatment of chronic atlantoaxial rotatory fixation

Retrospective analysis of atlantoaxial rotatory fixation describing age distribution and gender ratio in children and adolescents: A preliminary report

INTRODUCTION

Atlantoaxial rotatory fixation (AARF) in children presents with an acute onset of neck pain. Almost all cases heal within a few days of onset and are treated conservatively. Because few cases of AARF have been reported, the age distribution or gender ratio of AARF in the child population have not been described enough. In Japan, the social insurance system covers all citizens. Thus, we used insurance claims data to investigate the features of AARF. The aim of this study is to examine the age distribution, compare gender ratio and determine the recurrence proportion of AARF.

METHODS

We used the JMDC database to search for claims data submitted between January 2005 and June 2017 for cases of AARF in patients aged <20 years.

RESULTS

We identified 1949 patients with AARF, of which 1102 (56.5%) were male. The mean age was 98.3 ± 42.2 months and 91.6 ± 38.4 months in males and females, respectively, and males with AARF were significantly older at onset than females with AARF (p < 0.001). In both sexes, the highest frequency of AARF occurred when the patient was 6 years old. There were 121 (6.2%) cases of recurrent AARF (male: 61, 5.5%; female: 60, 7.1%), but the age differences between the sexes in these cases were not statistically significant.

CONCLUSIONS

This is the first report to describe the characteristics of the study population of AARF. Males were more likely to suffer from AARF than females. Furthermore, age (in months) at AARF onset was significantly higher in males than in females. Recurrence rate was not significant in both sexes.

New Subtype of Atlantoaxial Rotatory Fixation (Type IIIa)

OBJECTIVE

Some atlantoaxial rotatory fixations (AARFs) cannot be classified according to the Fielding and Hawkins classification. This study aimed to introduce a new subtype of AARF (type IIIa AARF) with a C1 anterior displacement >5 mm, but with one lateral mass being displaced anteriorly and another posteriorly.

METHODS

Data from 10 cases of AARF with anterior C1 displacement of >5 mm were retrospectively reviewed. The exclusion criteria were as follows: 1) type I, II, or IV AARF according to the Fielding and Hawkins classification; 2) cases caused by trauma, tumor, or infection; 3) AARF with os odontoideum or odontoid fracture; and 4）age ≥18 years. Imaging features were analyzed. The atlanto-dental interval was measured to evaluate C1 anterior displacement.

RESULTS

Three cases that did not match type III AARF were classified under type IIIa AARF. They had the following common imaging features: 1) atlanto-dental interval of >5 mm, being similar to type III AARF; 2) one lateral mass of C1 displaced anteriorly and the other posteriorly (the most important feature distinguishing the type from type III AARF in which both C1 lateral masses displaced anteriorly); and 3) C1-C2 separation angle (mean 44.2 ± 2.9°) being larger than that in type III AARF.

CONCLUSIONS

AARF with anterior C1 displacement of >5 mm, but with one lateral mass displaced anteriorly and the other posteriorly, was defined as type IIIa AARF. It should not be confused with type III AARF because these 2 types differ in biomechanics and imaging parameters.

Atlantoaxial rotatory dislocation: Surgical treatment in a pediatric patient cohort

•Surgical correction of AARD is an appropriate method of treatment after failed non-operative therapy.•The technique of surgical reduction and C1-C2 fixation using Harms/Goel technique provides excellent clinical outcomes.•In case of traumatic AARD we recommend to consider temporary fixation.

A pediatric case of axial rotary fixation associated with severe head trauma requiring emergency craniotomy for hematoma removal

Background

Atlantoaxial rotatory fixation (AARF) causes the atlantoaxial joint to be fixed in a rotated position, resulting in painful torticollis. We report a case of pediatric AARF associated with severe head trauma requiring emergency craniotomy and was treated with conservative treatment.

Case presentation

A 10-year-old boy was struck by a van while walking across the street. Upon admission to our trauma care center, his Glasgow Coma Scale score was 11 points (E3V3M5), pupils were 4 mm bilateral regular circles, and other vital signs were stable. Plain computed tomography (CT) revealed left acute epidural hematoma, traumatic subarachnoid hemorrhage, cerebral contusion, pneumoencephalopathy, and rightward deviation of the axial vertebra. We performed an emergency craniotomy due to an enlarged hematoma on a repeat head CT scan and decreased level of consciousness. Based on imaging studies, rightward deviation of the axial vertebra was diagnosed as AARF; however, since the patient was already on ventilatory management and no physical findings were obtained, conservative treatment with cervical collar fixation was started. His condition improved, and he was extubated on day 3, released from the cervical collar on day 10, discharged from the hospital on day 17, and followed-up until day 32.

Conclusions

AARF is often caused by minor trauma or inflammation in children; however, we experienced a case complicated by severe head trauma, which was treated conservatively and showed a good clinical progress. Since AARF treatment depends on the length of time from onset, early diagnosis, in trauma care, carefully assessing factors other than major trauma, will lead to improved prognosis.

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.

Clinical Features of Kawasaki Disease With Atlantoaxial Rotatory Fixation

PURPOSE

Atlantoaxial rotatory fixation (AARF) is a rare complication of acute Kawasaki disease (KD). Early diagnosis and intervention are important for AARF because delayed diagnoses may incur neurological sequelae. However, previous studies on AARF associated with KD are limited, and its clinical characteristics and course are unknown. This study aimed to examine the clinical features and treatment course of KD with AARF using a Japanese national inpatient database.

METHODS

Using the Diagnosis Procedure Combination database, we identified KD patients who received intravenous immunoglobulin (IVIG) treatment between July 2010 and March 2020. The clinical characteristics of KD patients with AARF and their risk factors were evaluated using multivariable logistic regression analysis. We also examined the relationship between AARF, the proportion of coronary artery abnormalities (CAAs), IVIG resistance, length of stay and medical costs.

RESULTS

We identified 71,913 patients with KD, 166 of whom had AARF. The AARF group had older age, heavier bodyweight and atypical KD. In multivariable analysis, AARF was associated with older age [odds ratio (OR): 1.24; 95% confidence interval (CI): 1.19-1.29], lower body mass index (OR: 0.89; 95% CI: 0.82-0.96) and atypical KD (OR: 1.95; 95% CI: 1.12-3.40). AARF was not associated with CAAs (OR: 0.73; 95% CI, 0.23-2.32) and IVIG resistance (OR: 1.05; 95% CI, 0.74-1.49). However, AARF was associated with higher medical costs (difference, US$1064; 95% CI: 346-1781) and longer hospital stay (difference, 3.1 days; 95% CI: 1.7-4.4).

CONCLUSION

AARF in patients with acute KD should be considered if cervical symptoms present in older patients with atypical KD.

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.

Spontaneous Osseous Fusion after Remodeling Therapy for Chronic Atlantoaxial Rotatory Fixation and Recovery Mechanism of Rotatory Range of Motion of the Cervical Spine

We aimed to investigate the risk factors of spontaneous osseous fusion (SOF) of the atlantoaxial joint after closed reduction under general anesthesia followed by halo fixation (remodeling therapy) for chronic atlantoaxial rotatory fixation, and to elucidate the recovery mechanism of the rotatory range of motion (ROM) after halo removal. Twelve patients who underwent remodeling therapy were retrospectively reviewed. Five patients with SOF were categorized as the fusion group and seven patients without SOF as the non-fusion group. Three dimensional CT was used to detect direct osseous contact (DOC) of facet joints before and during halo fixation, while dynamic CT at neutral and maximally rotated head positions was performed to measure rotatory ROM after halo removal. The duration from onset to initial visit was significantly longer (3.2 vs. 5.7 months, p = 0.04), incidence of DOC during halo fixation was higher (0/7 [0%] vs. 4/5 [80%], p = 0.004), and segmental rotatory ROM of Occiput/C1 (Oc/C1) at final follow-up was larger (9.8 vs. 20.1 degrees, p = 0.003) in the fusion group. Long duration from the onset to the initial visit might induce irreversible damage to the articular surface of the affected facet, which was confirmed as DOC during halo fixation and resulted in SOF. Long duration from the onset to the initial visit and DOC during halo fixation could be used to suggest the risk for SOF. Nonetheless, rotatory ROM of Oc/C1 increased to compensate for SOF.

Concomitant atlantoaxial and atlanto-occipital rotatory dislocation in children: Radiological features, diagnostic pitfalls, and long-term outcome

While the pathological manifestation of atlantoaxial rotatory dislocation has been well described in the medical literature, the combined dislocation of the atlantoaxial and atlanto-occipital joints, or OAARD - short for occipital-atlantoaxial rotatory dislocation - is a condition which has been poorly elucidated and probably underdiagnosed. We believe that the pathogenesis of combined atlantoaxial and atlanto-occipital dislocation is most likely a result of untreated atlantoaxial rotatory dislocation leading to chronic secondary compensation measures occurring at the occiput-C1 joints. Unique clinical and radiological features lead to difficulty in diagnosis, and conventional treatment algorithms may not apply. This paper describes a combination of clinical and radiological features which can help clinicians correctly diagnose and treat OAARD.

Primary treatment of atlantoaxial rotatory fixation in children: a multicenter, retrospective series of 125 cases

OBJECTIVE

The primary treatment for atlantoaxial rotatory fixation (AARF) remains controversial. The aim of this study was to investigate the primary treatment for AARF and create an algorithm for primary treatment.

METHODS

The authors analyzed the data of 125 pediatric patients at four medical institutions from April 1989 to December 2018. The patients were reported to have neck pain, torticollis, and restricted neck range of motion and were diagnosed according to the Fielding classification as type I or II. As a primary treatment, 88 patients received neck collar fixation, and 28 of these patients did not show symptom relief and required Glisson traction. Thirty-seven patients were primarily treated with Glisson traction. In total, 65 patients, including neck collar treatment failure patients, underwent Glisson traction in hospitals.

RESULTS

The success rate of treatment was significantly higher in the Glisson traction group (97.3%) than in the neck collar fixation group (68.2%) (p = 0.0001, Wilcoxon test). In the neck collar effective group, Fielding type I was more predominant (p = 0.0002, Wilcoxon test) and the duration from onset to the first visit was shorter (p = 0.02, Wilcoxon test) than that in the neck collar ineffective group. Using multivariate logistic regression analysis with the above items, the authors generalized from the estimated formula: logit [p(success group by neck collar fixation group)|duration from onset to the first visit (x1), Fielding type (x2)] = 0.4(intercept) - 0.15x1 + 1.06x2, where x1 is the number of days and x2 = 1 (for Fielding type I) or -1 (for Fielding type II). In cases for which the score is a positive value, the neck collar should be chosen. Conversely, in cases for which the score is a negative value, Glisson traction should be the first choice.

CONCLUSIONS

According to this formula, in patients with Fielding type I AARF, neck collar fixation should be allowed only if the duration from onset is ≤ 10 days. In patients with Fielding type II, because the score would be a negative value, Glisson traction should be performed as the primary treatment.

A Rare Case of Nontraumatic Atlantoaxial Rotatory Fixation in an Adult Patient Treated by a Closed Reduction: A Case Report

CASE

A 42-year-old woman presented with a severe neck pain and torticollis due to uncertain etiology. Because her radiographs and computed tomography revealed atlantoaxial rotatory fixation (AARF) that is an extremely rare condition in the adult population, a nonsurgical treatment was initially applied. Because 3 weeks of indirect traction failed, closed reduction was performed under general anesthesia at 2 months after onset, and her symptoms markedly improved without any complications and recurrence.

CONCLUSION

Closed reduction under general anesthesia for nontraumatic AARF in adult patients might be an effective treatment option, even for chronic cases or intractable cases by traction treatment.

New Simple 3-Dimensional Computed Tomogram Classification Leading to Successful Conservative Treatment in 51 Atlanto-Axial Rotatory Fixation Children

OBJECTIVE

to present a new and easy classification of atlanto-axial rotatory fixation (AARF) and to investigate the efficiency of conservative treatment of AARF.

BACKGROUND

Although there is a precise definition and diagnostic classification of AARF, there is still significant difficulty in measuring the atlas and axis angles because all of the atlas or axis cannot be seen in a certain 2-dimensional computed tomogram image. In addition, some recent case reports showed that long-term conservative treatment can reduce pediatric AARFs, even that are severe or chronic.

METHODS

Fifty-one children with AARF were analyzed retrospectively with new 3-dimensional computed tomogram (3DCT)-based AARF classification; the mean age was 72.7 ± 35.2 months (19-139 months). In the new AARF classification, type 1 was defined as that when the C1C2 angle is not 0° on midline and type 2 as that when the C1C2 angle is 0° on the midline.

RESULTS

All 7 children with AARF type 1 were treated successfully only with Halter tractions. Twenty among 44 children with type 2 did not show any difference in improvement compared with not-treated 24 children with type 2.

CONCLUSION

The first new AARF classification based on 3DCT appears to be easy to use and even the most severe children with AARF may be managed only with conservative treatment such as long-term Halter traction.

Systematic review of the nonsurgical management of atlantoaxial rotatory fixation in childhood

OBJECTIVE

Atlantoaxial rotatory fixation (AARF) is an acquired fixed abnormality of C1-2 joint rotation associated with torticollis in childhood. If the condition is left uncorrected, patients are at risk for developing C1-2 fusion with permanent limitation in the cervical range of movement, cosmetic deformity, and impact on quality of life. The management of AARF and the modality of nonsurgical treatment are poorly defined in both primary care and specialized care settings, and the optimal strategy is not clear. This systematic review aims to examine the available evidence to answer key questions relating to the nonsurgical management of AARF.

METHODS

A systematic review was performed using the following databases: PubMed, MEDLINE, Healthcare Management Information Consortium (HMIC), EMCare, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), British Nursing Index (BNI), and Allied and Complementary Medicine Database (AMED). Search criteria were created and checked independently among the authors. All articles with a radiological diagnosis of AARF and primary outcome data that met the study inclusion criteria were included and analyzed by the authors.

RESULTS

Search results did not yield any level I evidence such as a meta-analysis or randomized controlled trial. The initial search yielded 724 articles, 228 of which were screened following application of the core exclusion criteria. A total of 37 studies met the full criteria for inclusion in this review, consisting of 4 prospective studies and 33 retrospective case reviews. No articles directly compared outcomes between modalities of nonsurgical management. Six studies compared the outcome of AARF based on duration of symptoms before initiation of treatment. Comparative analysis of studies was hindered by the wide variety of treatment modalities described and the heterogeneity of outcome data.

CONCLUSIONS

The authors did not identify any level I evidence comparing different nonsurgical management approaches for AARF. There were few prospective studies, and most studies were uncontrolled, nonrandomized case series. Favorable outcomes were often reported regardless of treatment methods, with early treatment of AARF tending to yield better outcomes independent of the treatment modality. There is a lack of high-quality data, and further research is required to determine the optimal nonsurgical treatment strategy.

Atlantoaxial rotatory fixation in childhood: a staged management strategy incorporating manipulation under anaesthesia

AIMS

The aims were to evaluate the safety of manipulation under anaesthesia (MUA) for atlantoaxial rotatory fixation (AARF) and the relative efficacy of rigid collar vs halo-body orthosis (HBO) in avoiding relapse and the need for open surgery.

METHODS

Cases of CT-verified AARF treated by MUA were identified from a neurosurgical operative database. Demographic details, time to presentation and aetiology of AARF were ascertained through case note review. Cases were divided according to method of immobilisation after successful reduction, either rigid collar (group 1) or HBO (group 2). The primary outcome measure was relapse requiring open surgical arthrodesis.

RESULTS

Thirty-three patients (2.2-12.7 years) satisfied inclusion criteria. Time to presentation varied from 1 day to 18 months. There were 19 patients in group 1 and 14 in group 2. There were no adverse events associated with MUA. 9/19 (47%) patients in group 1 resolved without need for further treatment compared with 10/14 (71%) in group 2 (p = 0.15). Of the 10 patients who failed group 1 treatment, four resolved after HBO. A total of ten patients (30%) failed treatment and required open surgery.

CONCLUSIONS

MUA is a safe procedure for AARF where initial conservative measures have failed. MUA followed by immobilisation avoids the need for open surgery in over two thirds of cases. Immobilisation by cervical collar appears equally effective to HBO as an initial management, and so a step-wise approach may be reasonable. Delayed presentation may be a risk factor for relapse and need for open surgery.

Spontaneous morphological remodelling of the O-C1 joint after posterior fusion for occipitocervical dislocation

BACKGROUND

Traumatic occipitocervical dislocation (OCD) occurs due to fatal high-energy injury. Modern screw-based constructs enable successful reduction and stabilisation. In view of this, there are no previous reports on the spontaneous remodelling of the O-C1 joint after posterior fusion. We report the first case of postoperative spontaneous remodelling and stabilisation of the O-C1 joint after traumatic OCD.Case description: A 9-year-old girl suffered from traumatic OCD, accompanied by complete rupture of the O-C1-C2 ligamentous complex. Halo-vest fixation, and subsequently posterior fusion surgery from the occipital bone to C2, with autologous iliac crest bone graft and an allograft were performed. However, we could not achieve complete reduction of the O-C1 joint during surgery owing to extremely severe instability.Postoperative X-ray and computed tomography scan showed incomplete reduction of the O-C1 joint. Insufficient congruity of the O-C1 joint persisted. Afterwards, gradual spontaneous remodelling of the O-C1 joint occurred, both anteriorly and posteriorly 3 months postoperatively. Solid union was achieved 6 months postoperatively. Two years later, bilateral O-C1 joints in the patient were completely reformed and restabilised by incredible vigorous remodelling. Insufficient reduction and persisting poor joint congruence after surgery for OCD was probably restabilised by further spontaneous remodelling of articular morphology in such a young patient.

CONCLUSIONS

Postoperative spontaneous remodelling of the O-C1 joint after posterior reconstruction for OCD may occur in young patients. Incomplete reduction of the O-C1 joint during surgery may be acceptable due to the possibility of postoperative bone remodelling and restabilisation.

Long-Term Clinical and Radiologic Postoperative Outcomes After C1-C2 Pedicle Screw Techniques for Pediatric Atlantoaxial Rotatory Dislocation

BACKGROUND

Although C1-C2 pedicle screw techniques have been extensively reported in pediatric series, reports on their use have examined only small series with short follow-up periods. The aim of this study was to report pediatric patients with atlantoaxial rotatory dislocation treated with these techniques with a minimum 5-year follow-up.

METHODS

Retrospective review was performed of 27 pediatric patients with atlantoaxial rotatory dislocation who underwent C1-C2 pedicle screw fixation between 2004 and 2012. Clinical and radiographic outcomes were collected and compared with a control group.

RESULTS

Follow-up period was 60-142 months (mean 84 months). Torticollis was completely corrected postoperatively in all but 1 patient. All patients experienced significant pain relief and improvement in range of motion, and 6 patients with neurologic deficits experienced significant improvement postoperatively. Both atlantodental interval and space available for the cord were significantly improved compared with preoperative values. At final follow-up, curvature was lordotic in 20 cases and straight in 7 cases. Compared with the control group, range of motion of the patient group was not significantly different in any direction except in flexion and rotation. Mean anteroposterior diameters of the spinal canal at C1 and C2 levels were not significantly different from the control group.

CONCLUSIONS

C1-C2 pedicle screw techniques are safe and effective for treatment of atlantoaxial rotatory dislocation and result in no obvious limitation on growth in older children.

Chronic C1-C2 Rotatory Subluxation Reduced by C1 Lateral Mass Screws and C2 Translaminar Screws: A Case Report

BACKGROUND

C1-C2 rotatory subluxation can result from a variety or etiologies. Pediatric patients are particularly susceptible to C1-C2 rotatory subluxation. If left untreated the condition is termed an atlantoaxial rotatory fixation (AARF) and chronic neck pain and deformity can result. Patients failing conservative treatment or those with recurrent or chronic rotatory subluxation may require halo treatment or surgical intervention. This illustrative case report is about a patient with chronic C1-C2 AARF who was treated with C1 lateral mass screws and C2 translaminar screws, a treatment that has not been addressed by this technique in a pediatric population.

METHODS

This is a retrospective case review.

RESULTS

After an unsuccessful attempt at reduction, an 11-year-old girl underwent surgery to treat her C1-C2 AARF. Through an all posterior approach, screws were placed bilaterally into the C1 lateral masses followed by the placement of C2 translaminar screws bilaterally. A small amount of distraction was applied through the screw construct to open up the C1-C2 articulation and the AARF was open reduced and fused. A detailed postoperative computed tomographic scan focused on the occiput C1-C2 joint confirmed the anatomical reduction of the joint complex.

CONCLUSIONS

The patient had cosmetically pleasing relief of her torticollis and was doing well at 60 months after surgery.

LEVEL OF EVIDENCE

Level IV.

Temporary Internal Fixation Using C1 Lateral Mass Screw and C2 Pedicle Screw (Goel-Harms Technique) without Bone Grafting for Chronic Atlantoaxial Rotatory Fixation

BACKGROUND

The primary treatment strategy for chronic atlantoaxial rotatory fixation (chro-AARF) is traction followed by bracing or application of a halo device. However, to complete these conservative therapies, patient cooperation is mandatory. If conservative therapy fails, surgery is required for reduction and prevention of recurrence. It has been considered that surgery for atlantoaxial rotatory fixation necessitates solid bony fusion. However, once bony fusion is achieved, loss of range of motion is problematic. Here, we report a patient with chro-AARF who was successfully treated with temporary internal fixation using a C1 lateral mass screw and C2 pedicle screw (Goel-Harms technique) without any grafting of bone or use of bone substitute materials.

CASE DESCRIPTION

A 9-year-old boy with chro-AARF was referred to our institution. He had a history of pervasive developmental disorders. He did not cooperate for the completion of conservative therapy and could not tolerate this therapy. Therefore, the orthopedic staff and his parents considered surgery. Under general anesthesia, reduction was easily performed. The Goel-Harms screw-rod construct was completed as a temporary internal fixator without any grafting of bone or use of bone substitute materials. After 6 months, the screw-rod construct was removed. Removal of the screw-rod construct was performed easily without complication. There was no ankylosis of the C1-2 joint, and cervical range of motion was maintained 2.8 years after removal of the construct.

CONCLUSIONS

When conservative therapy cannot be continued, Goel-Harms surgery as a temporary internal fixator without bone grafting might be a suitable alternative for selected patients with chro-AARF.

Remodeling of the Cervical Facet Joint After Minimally Invasive Microendoscopic Resection for Cervical Osteoid Osteoma

STUDY DESIGN

Case report and systematic review of the literature.

OBJECTIVE

To describe a rare case of remodeling of the cervical facet joint after the microendoscopic resection of an osteoid osteoma.

SUMMARY OF BACKGROUND DATA

Osteoid osteoma, the third most common benign bone tumor, is often treated by image-guided percutaneous removal of the nidus. However, percutaneous resection poses technical difficulties when the tumor is located near the spinal cord or nerve roots. To our knowledge, there are no reports describing postoperative remodeling of the cervical facet joint after surgical resection of an osteoid osteoma.

METHODS

A 13-year-old boy was presented with neck pain that became worse at night. Computed tomography showed an osteoid osteoma in the right 7th cervical superior articular process. We successfully resected the nidus of the osteoid osteoma using minimally invasive microendoscopy.

RESULTS

The patient was symptom-free at the 1-year follow up, and computed tomography images showed new bone formation at the C6/7 facet joint.

CONCLUSION

This case indicates that microendoscopic resection is safe and effective for treating a cervical osteoid osteoma. This technique allowed total resection of the nidus with only minimal damage to the adjacent soft tissue and bone, and induced remodeling of the resection site.Level of Evidence: 4.

The delayed presentation of atlantoaxial rotatory fixation in children: a review of the management

AIMS

Although atlantoaxial rotatory fixation (AARF) is a common cause of torticollis in children, the diagnosis may be delayed. The condition is characterised by a lack of rotation at the atlantoaxial joint which becomes fixed in a rotated and subluxed position. The management of children with a delayed presentation of this condition is controversial. This is a retrospective study of a group of such children.

PATIENTS AND METHODS

Children who were admitted to two institutions between 1988 and 2014 with a diagnosis of AARF were included. We identified 12 children (four boys, eight girls), with a mean age of 7.3 years (1.5 to 13.4), in whom the duration of symptoms on presentation was at least four weeks (four to 39). All were treated with halo traction followed by a period of cervical immobilisation in a halo vest or a Minerva jacket. We describe a simple modification to the halo traction that allows the child to move their head whilst maintaining traction. The mean follow-up was 59.6 weeks (24 to 156).

RESULTS

Despite the delay in referral, the subluxation was successfully reduced in all children. Only two children required atlantoaxial fusion.

CONCLUSION

The results of our study suggest that normal anatomy with restoration of movement may be achieved even in cases of AARF presenting late, obviating the need for fusion. We also show a simple modification to the halo traction that allows the child to move their head about while still maintaining traction.

TAKE HOME MESSAGE

Prompt diagnosis and management with halo traction (with a simple modification as described) is associated with good results in patients with AARF who present late. Cite this article: Bone Joint J 2016;98-B:715-20.

Anterior Retropharyngeal Reduction and Sequential Posterior Fusion for Atlantoaxial Rotatory Fixation With Locked C1-C2 Lateral Facet

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To introduce a new type of atlantoaxial rotatory fixation (AARF) with a locked C1-C2 lateral facet and evaluate its therapeutic strategy.

SUMMARY OF BACKGROUND DATA

AARF presenting with torticollis and limited neck motion is commonly seen in teenagers. Fielding and Hawkins' classification is generally applied to AARF. Although conservative treatment is effective for acute AARF, it is often unsuccessful for chronic AARF, which ultimately requires surgery. We introduce a new type of chronic AARF with a locked C1-C2 lateral facet that does not fit into Fielding and Hawkins' classification and describe the appropriate treatment.

METHODS

Eight patients who had chronic AARF with a unilaterally locked C1-C2 lateral facet were referred to our clinic. Reduction had failed after traction for 3 to 4 weeks. After open release and reduction using the anterior retropharyngeal approach, we applied posterior C1-C2 transpedicular screw fixation with an autologous iliac bone graft for stage I or II.

RESULTS

The anterior retropharyngeal approach provided direct access to the C1-C2 locked lateral facet. The patient in an overall poor condition (stage II) underwent delayed posterior C1-C2 arthrodesis. The others (stage I) underwent immediate posterior C1-C2 arthrodesis. All patients were followed up for an average of 14.8 months (5-37 mo). Three-dimensional computed tomography revealed C1-C-2 arthrodesis bone graft fusion after an average of 3.1 months (2-4 mo). There was no recurrence of symptoms and no dislocations or internal fixation device loosening or breakage.

CONCLUSION

AARF with a locked C1-C2 lateral facet is a new type of AARF that cannot be classified using Fielding and Hawkins' classification. The anterior retropharyngeal approach for the release and reduction of AARF, followed by posterior C1-C2 arthrodesis is an effective therapeutic strategy for AARF with a locked C1-C2 lateral facet.

LEVEL OF EVIDENCE

4.

Spontaneous Ankylosis of Occiput to C2 following Closed Traction and Halo Treatment of Atlantoaxial Rotary Fixation

Study Design Case report. Objective We report a case of spontaneous atlantoaxial rotatory fixation (AARF) presenting 9 months after onset in an 11-year-old boy. Methods This is a retrospective case report of spontaneous ankylosis of occiput to C2 following traction, manipulative reduction, and halo immobilization for refractory atlantoaxial rotatory fixation. Results The patient underwent traction followed by close manual reduction and placement of halo immobilization after 6 months of severe spontaneous-onset AARF that had been refractory to chiropractic manipulation and physical therapy. Imaging demonstrated dislocation of the left C1-C2 facet joint and remodeling changes of the C2 superior facet prior to reduction, followed by near complete reduction of the dislocation after manipulation and halo placement. Symptoms and clinical appearance were satisfactorily improved and the halo vest was removed after 3 months. At late follow-up, computed tomography demonstrated complete bony ankylosis of the occiput to C2. The patient was found to be HLA B27-positive, but he had no family history of ankylosing spondyloarthropathy or other joint symptoms. The underlying reasons for spontaneous fusion of the occiput to C2 could include the traction, HLA-B27-related spondyloarthropathy, or arthropathic changes caused by traction, reduction, the inciting insult, or immobilization. Conclusion When discussing treatment of childhood refractory AARF by traction, closed manipulation, and halo immobilization, the possibility of developing "spontaneous" ankylosis needs to be considered.

Atlantoaxial rotatory dislocation (AARD) in pediatric age: MRI study on conservative treatment with Philadelphia collar--experience of nine consecutive cases

PURPOSE

Atlantoaxial rotatory fixation and atlantoaxial rotatory subluxation are the most frequent manifestations of atlantoaxial rotatory dislocation (AARD) in pediatric population and are often treated conservatively. The objective of this study is to correlate the changes highlighted on MRI T2-weighted and STIR sequences with the duration of conservative treatment.

METHODS

We analyzed nine consecutive patients treated surgically between 1 Jan 2006 and 1 Jan 2010 at the Policlinico Umberto I of Rome. All patients underwent cervical X-ray, computed tomography and magnetic resonance imaging (MRI) (T1 and T2-weighted, STIR, angio MRI). All patients were treated with bed rest, muscle relaxants and cervical collar, and radiological follow-up with MRI and cervical X-ray was performed.

RESULTS

According to Fielding's classification, we observed seven patients with a type 1 subluxation and two patients with a type II subluxation. In type 1, STIR and T2 sequences showed a hyperintensity in the alar and capsular ligaments and in the posterior ligamentous system, with integrity of the transverse ligament (LTA). In type 2, the hyperintensity also involved the LTA. During the follow-up, MRI showed a progressive reduction until the disappearance of the hyperintensity described, which was followed by a break with orthotic immobilization.

CONCLUSIONS

MRI with STIR sequences appears to be useful in addressing the duration of conservative treatment in AARD.

Management of chronic atlantoaxial rotatory fixation

STUDY DESIGN

Retrospective case series of chronic atlantoaxial rotatory fixation (AARF) treated by a novel closed reduction method (remodeling therapy) and review of the literature.

OBJECTIVE

To describe clinical features of chronic AARF and the rationale of the remodeling therapy.

SUMMARY OF BACKGROUND DATA

Treatment strategy for chronic recurrent AARF remains controversial. Posterior C1-C2 arthrodesis has been widely used for recurrent unstable AARFs after the closed reduction, and a variety of posterior fusion techniques have been advocated. In contrast, several investigators reported a chronic AARF case treated by a simple traction or closed reduction followed by cervical immobilization. Previously, we have found that a deformity of the superior C2 facet joint (C2 facet deformity) on three dimensional computed tomography (3D CT) reconstructions is a risk factor for recurrent subluxation. In addition, the remodeling of this C2 facet deformity by careful closed manipulation followed by halo fixation (remodeling therapy) could prevent the recurrence of subluxation.

METHODS

Twelve children with chronic AARF who sustained torticollis for an average of 4.4 months after the onset were referred to our clinic. The mean age at the initial visit was 7.8 years. All patients underwent the remodeling therapy as reported previously. Radiographic findings and clinical courses were retrospectively reviewed. Treatment methodology, pearls, and pitfalls of the remodeling therapy were discussed with review of the literature.

RESULTS

3D CT images before reduction revealed persistent atlantoaxial subluxation and the C2 facet deformity in the dislocated side in all cases. Follow-up 3D CT scans demonstrated the remodeling of the C2 facet deformity at an average of 2.4 months after successful reduction of subluxation. Neither recurrence of symptoms nor subluxation was observed at a mean follow-up of 42 months in any case. The cervical range of motion was 73.9° at the dislocated and 83.5° at the contra-dislocated side from the midline.

CONCLUSION

Chronic irreducible and recurrent unstable AARF should be initially managed by remodeling therapy using the facet deformity sign as a clinical index, if the C1 and C2 have not been osseously fused.