1. The frequency of variable degrees of ischaemia of soft tissue in closed tibial and fibular shaft fractures is emphasised.

2. Two cases with ischaemia of calf musculature are described.

3. A follow-up study of 100 cases of closed tibial shaft fractures is analysed; ten patients were found to be affected.

4. The anatomical and pathological changes are discussed.

5. A plea is made for early surgical exploration in cases manifesting signs of ischaemia.