Screws with other types of heads are also known as cap screws in the larger sizes and as machine screws in the smaller sizes.

The improvement of the design facilitate the insertion of the nail, decrease the stress to the lateral wall, low profile nail end and end cap reduce soft tissue irritation.

Conclution TEINs and end caps are effective methods for the length-unstable femoral shaft fracture in children. These results indicated that the risk of TEINs push-out can be reduced.