Surgical repair of bilateral lateral patellar luxation in a foal using block-recession trochleoplasty and polypropylene mesh reinforcement: Case report and review of literature.

Overview

• This study reports on the surgical treatment of a 2-month-old foal with bilateral lateral patellar luxation using block-recession trochleoplasty and polypropylene mesh reinforcement, demonstrating successful correction and improved limb function.

Introduction and Background

• Patellar luxation in horses is an uncommon orthopedic disorder where the kneecap (patella) dislocates from its normal position.
• The lateral form, where the patella dislocates toward the outside of the leg, often has a congenital (present at birth) basis, but is rarely reported compared to other species.
• Existing literature contains only sporadic descriptions of surgical approaches for this condition in equines, with no standardized treatment strategy.

Case Description

• The patient was a young Italian Trotter foal, aged 2 months, affected bilaterally, meaning both stifles (equine knees) exhibited lateral patellar luxation.
• Preoperative examination diagnosed the bilateral nature and severity of the luxations, confirming the need for surgical intervention.

Surgical Procedure

• The surgical correction was staged, meaning each stifle was operated on separately at different times to provide focused treatment and recovery.
• A block recession trochleoplasty was performed: this involves creating a deeper groove in the trochlea (a groove in the femur bone where the patella sits) by removing a block of bone and then replacing it deeper, allowing the patella to fit more securely.
• To reinforce the surgical repair, polypropylene mesh was applied to strengthen medial imbrication sutures. Medial imbrication refers to tightening the medial (inner) structures of the joint to prevent lateral displacement of the patella.
• Polypropylene mesh is a synthetic material commonly used in hernia repairs to provide additional strength; its novel use here aimed to improve stability of the patella and repair site.

Postoperative Findings and Outcomes

• Intraoperative inspections confirmed correct alignment and positioning of the patella following surgery on each limb.
• Postoperative evaluation showed improved tracking of the patella within the trochlear groove during movement, indicating restoration of normal biomechanics.
• Quadriceps muscle mechanism alignment was restored, ensuring proper muscle-limb function and reducing risks of re-luxation.
• The foal achieved favorable functional outcomes, exhibiting better limb usage and joint stability after recovery.

Significance and Implications

• This case demonstrates that block recession trochleoplasty can effectively deepen the trochlear groove to stabilize the patella in equine patients with lateral luxation, addressing the underlying bony deformity contributing to dislocation.
• Using polypropylene mesh to reinforce soft tissue repairs represents an innovative adjunct technique enhancing the strength and durability of medial soft tissue imbrication sutures in horses.
• The combined approach may offer a valuable surgical option in treating equine patellar luxation cases, especially those complicated by conformational challenges or bone abnormalities.
• The report enriches limited veterinary literature on equine stifle luxation surgery and encourages further investigation into these techniques for broader clinical use.