1. The results of the by-pass grafting operation in eleven cases of pseudarthrosis of the tibia in childhood are presented. 2. The operation was successful in securing sound bone union in nine cases, and unsuccessful in two. 3. The causes of failure in the two unsuccessful cases are analysed. 4. The possible causes of occurrence and persistence of tibial pseudarthrosis in childhood are discussed. 5. It is suggested that the pseudarthrosis results from a fatigue fracture of a congenitally abnormal tibia, but that its persistence depends entirely on mechanical factors. 6. There is evidence to suggest that the underlying congenital abnormality may arise from dysplasia of the mesenchyme.
Patellectomy is at present the best operation for recurrent dislocation, not only because the immediate result is excellent, but because it avoids the later arthritis which must inevitably arise if a patella so damaged is retained.