1. Five cases of postero-lateral dislocation of the knee with capsular interposition are described.

2. The mechanism of the injury is considered in the light of the case histories and the findings at operation.

3. The constant clinical findings associated with this injury are described.

4. Open reduction is recommended: with early operation the prognosis for function and stability is good.

1. A case of post-tetanic kyphosis is reported.

2. The clinical and radiographic features are described.

3. The theories of the mechanism of production of the deformity are discussed.