Authors of section

Author

Denis Marcellin-Little

Executive Editor

Amy Kapatkin

General Editor

Noel Moens

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Fragment excision or reconstruction

1. General considerations

In some instances, comminution may be present on the medial or lateral aspect of the patella, but the patellar mechanism remains intact. For these patients, the removal of these small comminuted fragments will suffice.
Patellar fragment excision

2. Preparation and approach

The patient is positioned in dorsal recumbency. The pelvic limb is extended.

Dog in dorsal recumbency
A sagittal or parasagittal skin incision is made over the patella.
Sagittal or parasagittal skin incision
A lateral parapatellar or medial parapatellar dissection is performed along the patellar ligament and patella proximally to the quadriceps muscle.

The direction of the approach is based on the location of the comminution.
Lateral parapatellar dissection

3. Surgical technique

Non-reconstructible small fragments are removed.
Non-reconstructible fragments are removed
The joint is lavaged to flush out any remaining small bone fragments.

4. Closure

The stifle joint is sutured using monofilament absorbable suture material. The wound is closed in layers.
The stifle joint is sutured

5. Aftercare

General considerations

Limb disuse after the repair of a patellar fracture is unusual. Most dogs start weight bearing within 3 days of surgery.

The focus of physical rehabilitation is to:

  • Avoid loss of stifle joint motion, particularly loss of extension
  • Avoid excessive stress on the surgical repair during the healing period
  • Promote low-impact weight bearing pelvic limb exercise

The stifle joint is protected and partially immobilized if deemed necessary for approximately 14 days.

Cryotherapy and passive range of motion are indicated but not possible if immobilization is used.

Activity is limited to leash walks until bone healing is radiographically evident.

Phase 1: 1-3 days after surgery

The aim is to reduce the edema, inflammation and pain using cryotherapy anti-inflammatory and analgesic medications.

Gentle passive range of motion of the hip and stifle joint can be initiated to promote mobility and joint health.

Phase 2: 4-14 days after surgery

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

Anti-inflammatory and analgesic medications may still be needed.

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

Phase 3: 14 days-8 weeks after surgery

Rehabilitation therapy is continued.

10-14 days after surgery the sutures are removed.

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

6. Case example

Ventrodorsal radiograph of a 6 months-old female whippet. An ill-defined bone opacity is visible on the lateral aspect of the left patella.
That bone opacity is not visible on the mediolateral radiographic view.
Ventrodorsal radiograph of a 6 months-old female whippet
On this distoproximal oblique radiographic projection of the dog the comminution is visible on the lateral aspect of the patella.
Distoproximal oblique radiographic projection of patellar comminution
A lateral parapatellar approach has been performed. Intraoperative picture showing the comminution on the lateral aspect of the patella.
Lateral parapatellar approach
Picture showing the patella after comminuted fragments removal.
Patella after comminuted fragments removal