Congratulations to Devi (together with collaborators Rebecca and Colin Boyle) on publication of her paper entitled “Quantifying the tolerance of chick hip joint development to temporary paralysis and the potential for recovery” in Developmental Dynamics.
In this paper, we wanted to discover when- and for how long- fetal movements are most important for development of the hip joint, in order to better understand conditions affecting the skeletons of babies who may have had restricted or reduced movements in utero, including developmental dysplasia of the hip (where the hip joint is unstable) and arthrogryposis (multiple joint contractures). We also wanted to know if joint development can be “rescued” by external manipulation even when immobilised.
We varied the initiation and duration of drug-induced paralysis in the chick embryo, and found that a three day period between 4 and 7 embryonic days was most important for hip joint shape. In terms of hip joint development, this timeline is equivalent to roughly 10 to 12 gestational weeks in humans, and means that the end of the first trimester would be a useful time for targeted screening for arthrogryposis and hip dysplasia. We found that cavitation was more dependent on duration of paralysis, rather than timing.
When we externally manipulated the immobilised chick limbs, the hip joints had more normal shapes, and more normal progression of cavitation, compared to the contralateral limbs of the same chicks. This implies that the developing limb has the potential to recover from periods of immobility, and external manipulation provides an innovative avenue for prevention and treatment of developmental joint pathologies.
The full paper is available open-access here. The research was funded by ERC Starting Grant #336306.