NAVLE Equine Lameness and Diagnostics 4 — Questions and Answers
Question 1: A 6-year-old Standardbred pacer presents with hindlimb lameness localized to the hock. Radiographs reveal periarticular osteophytes at the distal intertarsal and tarsometatarsal joints. The MOST appropriate treatment is:
- Arthroscopic joint lavage of the tarsocrural joint
- Intra-articular corticosteroids into the affected low-motion joints (Correct answer)
- Cunean tenectomy alone
- Neurectomy of the tibial nerve
Correct answer: Intra-articular corticosteroids into the affected low-motion joints
Bone spavin (osteoarthritis of the low-motion hock joints) is treated with intra-articular corticosteroid injections into the distal intertarsal and tarsometatarsal joints to reduce inflammation and pain.
Question 2: Which diagnostic nerve block would be used to specifically desensitize the coffin joint without affecting the navicular bursa?
- Palmar digital nerve block
- Intra-articular distal interphalangeal joint block (Correct answer)
- Low palmar (low 4-point) nerve block
- Abaxial sesamoid nerve block
Correct answer: Intra-articular distal interphalangeal joint block
Direct intra-articular injection into the coffin joint (DIP joint) selectively anesthetizes the joint space while sparing the navicular bursa, unlike perineural blocks that affect both structures.
Question 3: A horse is diagnosed with suspensory ligament desmitis in the proximal metacarpal region. Which diagnostic imaging modality provides the BEST detail of proximal suspensory pathology in this region?
- Radiography
- Ultrasonography (Correct answer)
- Thermography
- Nuclear scintigraphy
Correct answer: Ultrasonography
Ultrasonography is the modality of choice for soft tissue structures like the proximal suspensory ligament, providing real-time imaging of fiber pattern disruption, core lesions, and enthesopathy.
Question 4: A 3-year-old Thoroughbred filly in training develops acute hindlimb lameness after a workout. A 'popping' sound was heard at the moment of injury, and there is marked stifle effusion. The MOST likely diagnosis is:
- Upward fixation of the patella
- Patellar fracture or cranial cruciate ligament injury (Correct answer)
- Femoral nerve paralysis
- Hip luxation
Correct answer: Patellar fracture or cranial cruciate ligament injury
Acute onset of severe stifle lameness with an audible pop and joint effusion in a performance horse is most consistent with patellar fracture or stifle ligament injury.
Question 5: Cunean bursitis in horses with bone spavin is associated with inflammation of which structure?
- Navicular bursa of the hind foot
- Bursa beneath the cunean (medial) branch of the cranial tibial tendon (Correct answer)
- Calcaneal bursa
- Bicipital bursa of the shoulder
Correct answer: Bursa beneath the cunean (medial) branch of the cranial tibial tendon
Cunean bursitis involves the bursa located beneath the cunean branch of the cranial tibial tendon as it crosses the medial aspect of the hock, often concurrent with bone spavin.
Question 6: When evaluating a horse for subtle hindlimb lameness, which surface is MOST useful for accentuating the gait abnormality?
- Soft, deep sand arena (Correct answer)
- Firm, level asphalt surface
- Grass pasture
- Rubber-matted stall aisle
Correct answer: Soft, deep sand arena
A soft, deep surface increases concussion and proprioceptive demands on the hindlimb, accentuating subtle lameness signs that may not be visible on a firmer surface.
Question 7: A 12-year-old Quarter Horse mare has progressive forelimb lameness with a history of repeated intra-articular coffin joint injections. Radiographs now show marked remodeling of the coffin joint. The MOST appropriate next diagnostic step is:
- Repeat palmar digital nerve block
- MRI of the foot to evaluate soft tissue and bone detail (Correct answer)
- Radiographs of the opposite forelimb for comparison only
- Ultrasound of the superficial digital flexor tendon
Correct answer: MRI of the foot to evaluate soft tissue and bone detail
MRI provides superior detail of both bony and soft tissue structures within the hoof capsule, allowing comprehensive evaluation of all coffin joint components when standard diagnostics have been inconclusive.
NAVLE Equine Lameness and Diagnostics 4
A 6-year-old Standardbred pacer presents with hindlimb lameness localized to the hock.
Radiographs reveal periarticular osteophytes at the distal intertarsal and tarsometatarsal joints.
The MOST appropriate treatment is: