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.

Atlantoaxial Rotatory Dislocation: Delayed Diagnose Will Result in More Invasive Treatment Options

Purpose The atlantoaxial joint represents the most mobile joint complex within the spine, secured by ligaments and capsules. Integrity of the atlantoaxial joint is crucial with respect to the mobility of the head and the upper spine. Atlantoaxial rotatory dislocation is the most common type of injury within this joint in children and is characterized by a typical position of the head (cock robin position). Nevertheless, this type of injury is frequently overlooked. The purpose of the current study was threefold. First, the characteristics of the patients with atlantoaxial dislocation were identified. Next, we checked if the time to treatment did influence the type of treatment. Finally, we checked if the age of the child at the time of treatment influenced the type of treatment. Methods Forty-four children, who were treated consecutively due to atlantoaxial dislocation at a single spine center between September 1993 and October 2018, are analyzed retrospectively regarding age, sex, symptoms, etiology, time to diagnosis, time to treatment, and outcome. Results Forty-four children (30 girls, mean age 8.9 years) were included in the study. The cock robin head position was found in all of them, but neurological deficits were not found in any of them. In 21 patients, dislocation was caused by previous infection (Grisel's syndrome), whereas in 19 patients, dislocation was due to minor trauma. In 4 cases, etiology remained unknown. Mean time to sufficient treatment was 178 days. Eighteen patients received closed reduction and immobilization after 57 days at mean. Open reduction followed by temporary fixation was done in 12 patients after a mean time gap of 188 days. Bony atlantoaxial fusion was necessary in 14 children, who were diagnosed after 319 days on average. Invasiveness of treatment was dependent on the time delay between development of dislocation and treatment; a significant difference was found between invasiveness of treatment and time to treatment (Kruskal–Wallis test, p < 0,05). Moreover, older children were treated significantly more often with fusion than younger ones (χ 2, p = 0,002). Conclusion Young girls are predisposed to incur an atlantoaxial rotatory dislocation, which usually occurs due to minor trauma or infection. The cock robin position is characteristic, but neurological deficits are not common. There is a need for early and sufficient treatment because delayed treatment necessitates more invasive treatment, thus leading to a complete loss of function of the most mobile joint within the spine. Finally, older children are predisposed to more invasive treatment strategies.