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.

Gastrulation : Current Concepts and Implications for Spinal Malformations.

It has been recognised for over a century that the events of gastrulation are fundamental in determining, not only the development of the neuraxis but the organisation of the entire primitive embryo. Until recently our understanding of gastrulation was based on detailed histological analysis in animal models and relatively rare human tissue preparations from aborted fetuses. Such studies resulted in a model of gastrulation that neurosurgeons have subsequently used as a means of trying to explain some of the congenital anomalies of caudal spinal cord and vertebral development that present in paediatric neurosurgical practice. Recent advances in developmental biology, in particular cellular biology and molecular genetics have offered new insights into very early development. Understanding the processes that underlie cellular interactions, gene expression and activation/inhibition of signalling pathways has changed the way embryologists view gastrulation and this has led to a shift in emphasis from the 'descriptive and morphological' to the 'mechanistic and functional'. Unfortunately, thus far it has proved difficult to translate this improved knowledge of normal development, typically derived from non-human models, into an understanding of the mechanisms underlying human malformations such as the spinal dysraphisms and anomalies of caudal development. A paediatric neurosurgeons perspective of current concepts in gastrulation is presented along with a critical review of the current hypotheses of human malformations that have been attributed to disorders of this stage of embryogenesis.