To define the orthopaedic problems associated with pseudoachondroplasia (PSACH) and their functional impact. We reviewed the medical records of 12 consecutive patients presenting to our unit. Radiographic analysis of deformity included assessment of mechanical axis and dysplasia at hip, knee and ankle measured by acetabular index (AI), Reimer's migration percentage (MP), neck-shaft angle, distal lateral femoral (aDFLA) and proximal (mMPTA) and distal tibial angles. The paediatric/adolescent PODCI questionnaires and the SF36 were used to assess quality of life issues.Purpose
Methods
Although Bohler’s &
Gissane’s angles are measured in adult calcaneal fractures, it is not known if such measurements are reliable in children nor how such measurements vary with the age of the child. The Picture Archiving and Communications System (PACS) databases of 2 London Teaching Hospitals were searched and all children who had a lateral ankle xray taken as part of their attendance to the A&
E department were identified. Films were excluded if there was a fracture of the calcaneus or if the film was oblique or of poor quality. Bohler’s and Gissane’s angles were measured using the image viewer software. All patients’ films were measured on two separate occasions and by two separate authors to allow calculation of inter- and intra-observer variation. Interclass Correlation Coefficients (ICC) were used to assess the reliability of the measurements. 347 children were identified and after exclusions, 218 films were used for the study. The overall ICC for Bohler’s angle inter-obsever error was 0.91 and for intra-observer error was 0.92, giving excellent correlation. This reliability was maintained across the age groups. Gissane’s angle inter-observer error was very poor and the intra-observer error poor across the age groups, although accuracy did improve as the patients approached maturity. Further analysis of the Bohler’s angle showed a significant variation in the mean angle with age. Contrary to published opinion, the angle is not uniformly lower than that of adults but varies with age, peaking towards the end of the first decade before attaining adult values. We feel that measurement of Gissane’s angle is unreliable in children but measurement of Bohler’s angle is accurate and reproducible. Bohler’s angle varies with age and knowledge of Bohler’s angle variation is important in the evaluation of os calcis fractures in children.
Surgical treatment of complex deformities necessitates a detailed appreciation of the complex three dimensional abnormal anatomies involved. Preoperative planning for these complex cases traditionally involves x-ray and computerised tomography (CT). These modalities offer only two-dimensional images to represent three-dimensional anatomy. Advances in digital imaging have allowed three-dimensional reconstructions to be derived from CT images. These greatly improve understanding of complex deformities, but will never be able to replace the intuitive understanding that is gained by handling a physical model. The Rapid Prototyping technique Selective Laser Sintering (SLS) is used in the industrial setting to manufacture prototype models from Computer Aided Designs (CAD). This technology can be utilised to convert CT images into accurate three-dimensional physical models of the human bony anatomy. We present the use of SLS modelling to aid in the preoperative planning of complex reconstructive surgery in children. Cases include bladder exstrophy, developmental dysplasia of the hip and reconstruction of a complex elbow malunion. The models provide invaluable visual and tactile information to the operating surgeon, accurately demonstrating the abnormal anatomy in an easily comprehensible manner. They allow estimation of the magnitude and degree of corrections necessary and evaluation of bony deficiencies.
