Lag screws and neutralization plate

Lag screw and neutralization plate are mainly used for large fragments or long oblique fractures.

Note: Lag screws should only be used for fragments with a long enough contact zone to the main fragment.

The positioning and approach depend on the fracture location.

A lateral approach with the patient positioned in lateral recumbency is preferred for more proximal fractures.

A medial approach with the patient positioned in dorsal recumbency is preferred for more distal fractures.

The fracture is reduced with reduction forceps and kept in reduction with pointed reduction forceps.

The fracture is stabilized with two or more lag screws. Depending on the fracture geometry, it may be necessary to place screws in the location of the plate; in these cases, it is important to countersink the screw heads to permit accurate plate application.

Pearl: A lag screw can also be introduced through a plate hole in some instances.

Read more about lag screw fixation.

A plate with a neutralization function is used. The plate can either be a locking compression plate (LCP) or a dynamic compression plate (DCP).

The longest possible plate considering soft tissue trauma and the approach should be chosen. The plate's length should allow the placement of at least 3–4 screws in each major fragment.

Note: If using an LCP, contouring does not have to be as exact as when using a DCP.

Read more about plate preparation.

Following contouring, the plate is applied to the lateral surface for more proximal fractures or the medial surface for more distal fractures.

Two screws, one in the proximal fragment and one in the distal fragment, are inserted to position the plate optimally over the bone's length.

The first four screws are inserted alternatingly (one proximal, one distal) to fix the alignment.

The remaining screws are inserted according to the surgeon's preference.

All screws must be in either locking or neutral position.

5-month-old German Shepherd dog with a 12-A2 fracture following unknown trauma. The dog was presented 1–2 weeks after the injury had occurred, and there was already callus present.

The humeral fracture was repaired with two lag screws and a 10-hole 2.7 mm locking compression plate.

4-year-old Deutsch Drahthaar dog with 12-A2 fracture.

The fracture was stabilized using lag screws and a neutralization plated.

Follow-up radiographs after six weeks.

Follow-up radiographs after three months show a healed fracture.

The aim is to reduce edema, inflammation, and pain.

Integrative medical therapies, anti-inflammatory medication, and analgesics are recommended.

Note: Animals carry 2/3 of their weight on the front limb. Therefore, strict leash confinement or cage rest and no jumping are recommended until radiographs show signs of bone healing.

The aim is to resolve hematoma and edema, control pain, and prevent muscle contracture.

Anti-inflammatory and analgesic medications may still be needed. Rehabilitation and integrative medical therapies can be used.

A careful evaluation is recommended if the dog does not start to use the limb within a few days after surgery.

Early ambulation is aimed for.

Radial nerve neurapraxia may occur in some cases. This neurapraxia usually resolves within a few days.

10–14 days after surgery, the sutures are removed.

Radiographic assessment is performed every 4–8 weeks until bone healing is confirmed.

Note: It can be challenging to assess bone union on radiographs when bone healing occurs without callus formation.