Traumatic synovial herniation of the medial femorotibial joint as an aetiology of hindlimb lameness in a horse
Authors: Loppnow Zach R., Janke Jared, Klein Chelsea E., Tatarniuk Dane M.
Journal: Equine Veterinary Education
Summary
# Editorial Summary A three-year-old Quarter Horse presented with acute hindlimb lameness and moderate effusion of the medial femorotibial joint, with imaging revealing a disruption to the synovial membrane in the medial recess—a relatively uncommon presentation subsequently identified as a traumatic capsular tear at the medial collateral ligament attachment site via arthroscopy. The case highlights how seemingly straightforward joint effusions warrant thorough ultrasonographic assessment, as synovial herniation can easily be missed on clinical examination alone and may represent a distinct aetiology of stifle lameness. Following conservative management with autologous conditioned serum, rest, and firocoxib (an NSAID), the horse demonstrated significant lameness improvement, though post-treatment ultrasound confirmed persistence of the synovial hernia, suggesting the clinical improvement preceded complete structural resolution. For practitioners managing stifle lameness, this case underscores the importance of detailed soft tissue imaging of the joint capsule itself—particularly in young athletic horses with acute presentations—and suggests that traumatic synovial herniation may be compatible with functional recovery even without surgical intervention, though long-term follow-up data on recurrence and performance remain limited.
Read the full abstract on the publisher's site
Practical Takeaways
- •Traumatic synovial herniation is a potential but rare cause of acute hindlimb lameness; suspect it when grade 4/5 lameness occurs with medial femorotibial joint effusion
- •Ultrasound can identify synovial membrane disruption, but arthroscopy may be needed for definitive diagnosis and to assess capsular integrity
- •Conservative management with rest, NSAIDs, and biologic therapies can improve clinical lameness even when synovial hernias persist sonographically
Key Findings
- •Ultrasonography identified synovial membrane disruption in the medial femorotibial joint recess in a lame horse
- •Arthroscopy confirmed a tear in the joint capsule at the medial collateral ligament attachment
- •Treatment with autologous conditioned serum, rest, and firocoxib improved lameness grade from 4/5 to lower levels
- •Follow-up sonography revealed persistence of synovial hernia despite clinical improvement