1. One hundred and eight osteotomies were reviewed with regard to union, and fourteen were found to be ununited. In only one was non-union detected clinically; the others required radiographic demonstration. Tomographs were particularly helpful in confirming non-union.

2. Nine patients with non-union had pain, equal to or worse than before operation. The pain could not be distinguished from that of osteoarthritis of the hip.

3. Six of the patients with non-union needed an operation. Five had cancellous bone grafts followed by union in all except one.

4. The causes of non-union are reviewed. This complication was found to be less frequent in patients above sixty with stiff hips and bony collapse on the radiograph. Horizontal osteotomy with a displacement of not more than one-third of the diameter of the shaft reduced the incidence of non-union. The variable-angle nail-plate provided the best fixation. Traction provided no benefit and increased the incidence of non-union. Weight bearing is best avoided for eight weeks.

1. A case of pseudomalignant osseous tumour of soft tissue is reported.

2. The relationship between this condition and myositis ossificans is discussed and the importance of differentiating it from osteosarcoma is stressed.

1. Three cases of traumatic thrombosis of the iliac arteries and one case of a false aneurysm of the internal iliac artery following closed injuries are described.

2. Results of the treatment of these cases are discussed.