Equine Antebrachial Compartment Syndrome Secondary to Flexor Muscle Myopathy With Subsequent Muscle Atrophy And Tendonitis: A Case Report.

The study details a case of a 16-year old jumping stallion that, after an injury, developed a condition known as extremity compartment syndrome leading to muscle atrophy and tendonitis.

Clinical Presentation

• The horse experienced a significant swelling in the left antebrachial area (foreleg between the elbow and knee) and displayed noticeable lameness after suffering a fall.
• Although the horse was able to bear weight, it exhibited a severe degree of lameness at the walk, ranking 4 out of 5 on the American Association of Equine Practitioners (AAEP) lameness scale.
• A significant enlargement on the back side of the antebrachial area was observed during the clinical examination.

Diagnosis and Initial Treatment

• Exact diagnoses were established after a static musculoskeletal examination, along with radiography and ultrasonography investigations.
• The horse was diagnosed with a flexor muscle myopathy, a condition involving the muscle damage, and a suspected extremity compartment syndrome, a condition where increased pressure within one of the body’s compartments results in inadequate blood supply to tissues within that space.
• The horse received medical treatment and showed clinical improvement over several days.

Six-month Follow-Up and Recurring Symptoms

• After six months, the horse displayed atrophy, or wasting, of the flexor muscle, but had no problems walking or trotting.
• The horse was presented again after three more months, exhibiting an enlargement of the palmar left metacarpus (the equivalent of the human hand in terms of anatomical location), and was diagnosed with superficial digital flexor tendonitis, inflammation of the tendon.

Anatomical Considerations and Biomechanics

• The study provides discussion on the anatomical features of the affected region, along with the physiopathology, or the functional changes that accompany the compartment syndrome and myopathy – how the syndrome develops and the potential effects on the horse’s body.
• The possible biomechanics behind the muscle atrophy and tendonitis – the mechanical processes and movements within the body – post-injury are also explored.