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.
The direction of the approach is based on the location of the comminution.
3. Partial patellectomy
Small 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.
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.
The stifle joint is sutured using monofilament absorbable suture material. The wound is closed in layers.
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