Authors of section

Author

Denis Marcellin-Little

Executive Editor

Amy Kapatkin

General Editor

Noel Moens

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Salvage procedure

1. General considerations

The patella fracture is under tension and distracted apart by the pull of the quadriceps muscle group.
Acute patella fractures can be reduced. Chronic patella fractures may not be reducible.
The fixation method must resist the large tension forces constantly acting on the patella.
Every effort should be made to reconstruct the patella. If reconstruction is not possible, a partial or complete patellectomy is performed as a salvage procedure.
Partial patellectomy is more likely to be clinical successful than complete patellectomy, as it preserves the extensor lever arm. However, both have an unpredictable clinical outcome.
Comminuted non-reconstructible patella

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. Partial patellectomy

Small non-reconstructible fragments are excised and removed.
Non-reconstructible fragments are excised and removed
Reconstruction of the patellar tendon is required if the excised portion of the patella involves the tendon of insertion of the quadriceps or the origin of the patella ligament. Common tendon repair techniques include modified locking loop or three-loop pulley suture patterns. A detailed description of tendon repair techniques and postoperative protection are beyond the scope of this module.
Suturing technique

4. Total patellectomy

In rare instances where the entire patella is beyond reconstruction, a complete patellectomy can be performed. To perform this procedure, remove the entire patella by sharp dissection, ensuring maximal preservation of the extensor tendinous tissue. Tendon repair techniques are needed to connect the quadriceps femoris muscle to the tibial tubercle.
A detailed description of tendon repair techniques and postoperative protection are beyond the scope of this module.
Total patellectomy

5. Closure

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

6. 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.

Physical rehabilitation

Limb disuse is more likely to occur after a patellectomy than patellar fracture repair. 

The leg is immobilized for up to 6 weeks. Therapeutic exercises are initiated 6 weeks after surgery.