Sliding hip screws: modes of failure.

The modes of failure of the sliding hip screw devices were investigated by reviewing 223 cases. There were 35 mechanical failures. Two of these occurred when the components separated in highly comminuted fractures. The use of the locking screw is recommended to prevent this. The other 33 occurred when the device had lost its sliding action. The reasons for this included jamming, insufficient slide being available and additional fixation. To reduce the complication rate it is recommended that any additional fixation (such as cerclage wires) should be used with care to ensure that they do not block the barrel. For patients with short femoral necks, a shorter barrelled version of the device should be used as it would have a greater sliding capacity. Guidelines for its use are given.