K-wire and tension band fixation

The goal of 23-B1 fracture treatment is anatomical reduction, which can be achieved by placing a pointed reduction forceps across the fracture line or inserting a K-wire in the distal fragment.

The K-wire and tension band wire fixation is mainly indicated for small to medium breed dogs and cats.

The patient can be in dorsal or lateral recumbency.

In lateral recumbency, the affected leg should be in contact with the table.

A craniomedial approach to the distal radius is performed.

The goal is to achieve anatomical reduction.

Anatomical reduction is obtained with the help of one pointed reduction forceps placed across the fracture line.

Alternatively, the K-wire can be inserted in the distal fragment first and then used as a joystick to achieve reduction.

Appropriately sized K-wires and tension band wire are selected.

In some cases, the fragment is too small and it is not possible to place two K-wires, and a single K-wire plus tension band can provide enough stability.

A single K-wire is inserted normograde from the radial styloid process across the fracture line into the proximal fragment engaging the lateral cortex.

A second K-wire is inserted in parallel direction.

A small hole is drilled from cranial to caudal in the proximal fragment. The diameter of the drill hole should be optimized to the size of the tension band wire. The tension band wire diameter is selected to approximate the size of the K-wires.

The tension band wire is inserted through the hole, and the ends are crossed on the medial surface of the radius.

The wire is passed around the ends of the K-wires and back to the other end of the wire on the starting side of the bone. This creates a figure-of-eight pattern.

Twist knots are commonly used for tension band wires, although loop-style knots can also be used.

To effectively tighten a tension band wire with one knot, the tightening process must also draw in the slack in the arm opposite the one with the knot. Because the wire makes several tight bends, both through the hole in the bone and around the K-wires, this may not happen with a larger diameter wire.

A double knot technique is preferred to address this deficiency of the single knot technique.

A twist knot is tied in both arms of the figure-of-eight. When placing the wire, a loop is formed in the wire so that it is positioned between the hole and the K-wires in the first arm of the figure-of-eight.

The tension band wire is tightened by twisting the two knots.

Once the slack has been removed, the K-wires are bent over so that they lie flat to the bone. The bent K-wires are directed away from the pull of the wire by bending them away from the bone, cutting them with 2–3 mm of the bent arm, and rotating them to direct the arm away from the wire. The end will usually embed in the soft tissues around the fragment.

Once the final position of the K-wires is set, tightening of the figure-of-eight is completed.

In some cases, in smaller patients, two K-wires without a tension band wire may be an option when combined with a splinted bandage.

A Robert Jones or modified Robert Jones bandage can be applied for 1–3 days to decrease the edema and protect the surgical incision.

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

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

10–20 minutes of ice therapy is recommended every 8 hours in most cases.

The patient can immediately bear weight, but with strict control of activities.

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 patient is not starting to use the limb within a few days after surgery.

The sutures are removed 10–14 days after surgery.

Immature patients should be radiographed every 4 weeks.

A radiographic assessment is performed every 4–6 weeks until bone healing is confirmed, more frequent assessment may be necessary for skeletally immature patients.