The heads of Veterinary Instrumentation locking screws match perfectly with standard locking plates.

The fine threads of the head are tapered with a twin start which means that the screw head moves through the tapered locking hole at the same rate as the bone screw moves through bone.

This is important if the locking plate is not going to be pushed or pulled away from the bone.

The head of the screw is a standard hex drive. 2.5hex for the 3.5mm screws (5.0mm head) and 1.5hex for the 2.7mm screws (3.5mm head)

A dedicated drill guide LSDG35 which screws into the locking hole is required to ensure that the pilot drill of 2.7mm is exactly centred and at 90 degrees to the plate.

This screw has the same size head as the 3.5 screw but has a 2.7mm bone screw section. This scew only fits 3.5mm plates. They do not fit 2.7mm TPLO plates. (see below). These screws are useful where plate positioning places a plate hole close to the edge of the bone. Remember with locking plates it is not possible to angle screws away from bone margins. Use of the LS2735 series make just be enough to avoid the screw breaking out of the fragment. Also useful in trans-articular locking plates such as the pancarpal plate where typically smaller screws are required in the distal section. Use a 2.0mm pilot and drill guide LSDG35.

This screw has the smaller head diameter of the 2.4 locking screw. This is the 2.7 locking screw to fit the 2.7mm locking TPLO plate. Use a 2.0mm pilot plus Drill Guide LSDG2724. Use 1.5 hexagonal screwdriver, the same as for 1.5 and 2.0mm cortical screws.

Veterinary Instrumentation locking plates have round stacked locking holes to maximise the number of screws in any fragment. The round hole allows some angulation of standard cortical screws (7 degrees) but does not allow compression of the fracture site. Use of dual or combi holes does allow compression but a hole including both DCP and locking features is very long limiting the number of screws available for any bone fragment.