Abstract
A study of limb shortening after poliomyelitis in 225 children in whom paralysis was confined to one leg shows:
1. The paralysed leg became shorter than its fellow in 219 patients (97 per cent).
2. The discrepancy in leg length only once exceeded three and a half inches.
3. Both the tibia and the femur were shorter than their fellows in 171 out of 184 studied (93 per cent). In only one patient was the femur alone shortened.
4. Three patterns of progress of shortening are described. No evidence was found that reduction of shortening ever occurs.
5. It is impossible accurately to predict shortening. In general, the more severe the paralysis the greater the shortening, but there are notable exceptions.
6. No relationship could be found between the amount of shortening and the incidence of paralysis of any individual muscle-group.
7. There was no significant difference in leg shortening in adult life between those who had developed the disease in the first two years of life and those who had developed it later.
8. A cold blue limb is not more likely to undergo severe shortening.
9. When the paralysis was confined below the knee the greatest shortening seen was one and three-quarter inches. When muscles both above and below the knee were involved severe paralysis may produce shortening up to three and a half inches.
10. Lengthening of a paralysed leg can occur during the first two years after the onset of the disease, but this is always a temporary phase.
11. The cause of leg shortening is unknown. In only two patients in this series was there evidence of premature epiphysial fusion.
