Authors of section

Author

Cassio Ferrigno

Executive Editor

Amy Kapatkin

General Editor

Noel Moens

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Plate and rod

1. Principles

Plate-rod is a biological fixation technique. The intramedullary pin is used as a reduction device to align the fracture and to take the bone to its proper length. The two implants work together; The pin protects the repaired fracture against bending forces while the plate resists axial collapse, rotation, shear and bending. Without the pin, the bone plate would be subjected to high bending forces because the bone is not sharing any load.

plate and rod

2. Patient preparation

This procedure is performed with the patient placed in lateral oblique recumbency.

plate and rod

3. Approach

In order to gain access for anatomical reconstruction an open or open-but-do-not-touch (OBDNT) medial approach to the tibial shaft is performed.

For more information please see the open craniomedial approach to the tibial shaft.

Alternatively, a minimally invasive approach may be considered.

plate and rod

Approach for normograde insertion

This is an extra articular approach. Incision of the stifle joint capsule should be avoided.

Skin incision, dissection of subcutaneous tissue, and incision of the medial stifle fascia are performed over the craniomedial aspect of the tibia plateau.

For more details see the approach for normograde pin/nail insertion.

plate and rod

4. Surgical technique

Pin selection

The dimensions of the pin should be 35-40% of the isthmus of the medullary canal. This provides sufficient protection against bending forces while allowing placement of cortical screws in the proximal and distal parts of the tibia. Bicortical screws are preferred and usually possible with this pin size. If a bicortical screw cannot be placed, monocortical screws are acceptable in a plate-rod construct as long as overall, sufficient cortices are engaged.

plate and rod

Normograde pin insertion in the tibia

The appropriate size pin is inserted in a normograde fashion without entering the stifle joint.

The pin is started at a point on the tibia plateau just inside the medial cortex and halfway between the straight patellar tendon and the medial collateral ligament.

The pin is directed very slightly caudally in the direction of the tibial shaft and parallel to the medial cortex. The caudal angle must be shallow to allow the pin to bend slightly as it contacts the caudal cortex and aligns with the medullary cavity.

plate and rod

The pin is advanced through the proximal fragment. When using an open but do not touch approach, the tip of the pin can be cut and then directed into the distal fragment once the fracture is aligned. Cutting the tip of the pin minimizes the risk of penetration through the distal fragment cortex when the fracture is distracted.

The pin is advanced passing the fracture zone and reaching the distal segment.

Note: The pin tip is not always cut before advancing it. Care is needed when advancing the pin to avoid it penetrating the cortex or into the joint. Placing the pin with a hand chuck instead of a power drill is advised.

plate and rod

Reduction

The fracture is aligned and stabilized with bone-holding forceps, while the pin is advanced into the distal metaphyseal area.

plate and rod

Entering the talocrural joint with the tip of the pin must be avoided.

plate and rod

A second pin of the same length or fluoroscopy can be used to judge insertion length.

plate and rod

Validation of alignment and rotation

Once the bone length has been restored, it is necessary to check for correct alignment and rotation. Rotational alignment can be judged by palpation or by direct visualization of the relation between the tarsus and the stifle. Flexing and extending the tarsus and stifle will help to check the alignment of the repair.

Note: Position of the dog in dorsal recumbency permits a better three-dimensional view of the tibia, thus it helps in the verification of alignment.

plate and rod

Cutting the pin

The pin is cut close to the surface of the tibia plateau to prevent irritation of the straight patellar ligament or the medial joint capsule.

plate and rod

Plate selection

A bone plate is contoured to the shape of the bone. The length of the plate should allow placement at least three to four screws in each major fragment.

Note: Ideally a plate placed in bridging fashion should span at least 75% of the length of the bone.

Read more about plate preparation.

plate and rod

Temporary stabilization

The plate is secured to the bone with bone clamps and/or bone-holding forceps. Rotational alignment is verified again and corrected if necessary.

plate and rod

If a locking plate is used, temporarily stabilization is achieved using a push-pull device in each of the fragments.

plate and rod

Plate application

If possible, the plate is secured by inserting at least three bicortical screws in each major segment. This is easier to achieve proximally and distally because the bone tends to be larger in those locations.

The screws should be oriented in such way that they do not interfere with the intramedullary pin.

plate and rod

If the drill contacts the intramedullary pin, a monocortical screw can be used instead of a bicortical screw. Forcing a drill bit against the pin will likely result in breakage of the drill bit and potentially the screw hole will be unusable.

plate and rod

Locking plate

A locking plate can be used instead of a traditional bone plate. However, interference between the pin and the locking screws is likely. Using monocortical locking screws or a combination of non-locking and locking screws can provide adequate fixation. If a combination of screws is used, the plate must be anatomically contoured and the non-locking screws should be placed and tightened first because they will compress the plate to the bone.

plate and rod

5. Aftercare

Phase 1: 1-3 day after surgery

The aim is to reduce the edema, inflammation and pain. A Robert Jones or modified Robert Jones bandage can be used to decrease the edema and protect the surgical wound. Integrative medical therapies, anti-inflammatory medications and analgesics are recommended. In most cases, 10-20 minutes of ice therapy is recommended every 8 hours.

Phase 2: 4-10 days after surgery

The aim is to resolve the hematoma, edema and control pain, and prevent muscle contracture. Anti-inflammatory and analgesic medications may still be needed. Rehabilitation and integrative medical therapies can be used.

If the dog is not starting to use the limb within a few days after surgery, a careful evaluation is recommended.

10-14 days after surgery the sutures are removed.

Phase 3: 10 day-bone healing

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

Implant removal

More information about implant removal can be found here.