Veterinary Orthopedics: Horse Fractures

Approach to Fractures in the Horse

• This presentation details the approach to fractures in horses, covering diagnosis, imaging, clinical examination, and management.
• Key learning objectives include constructing a differential diagnosis, determining appropriate medical and surgical interventions, and assessing prognosis for common horse fractures.
• Common fracture types include distal phalanx fractures, limb fractures, and pelvic fractures.

Fracture Diagnosis

• History of lameness and trauma is crucial for diagnosing fractures in horses.
• Types of trauma include kicks, impacts, falls, and road traffic accidents (RTAs).
• Stress and non-physiological loading should also be considered.

Clinical Examination

• Safety is the first consideration.
• Cardiovascular status, external/internal haemorrhage, and dehydration should be assessed.
• The presentation, posture, swelling, and asymmetry of the limbs should be visually evaluated.
• Thorough palpation of the legs is essential, assessing for swellings, wounds, digital pulses, foreign bodies, hoof testers, pain, range of motion, and crepitus.

Typical Clinical Presentation

• Lameness can range from severe to mild.
• Signs of pain, swelling, wounds, crepitus, limb instability, pelvic asymmetry, and ataxia can indicate fractures.

Diagnosis - Imaging

• Radiography is the primary imaging tool.
• Be aware of lag periods in diagnosis; hairline or non-displaced fractures may not initially show up on radiographs.
• Multiple views are often necessary.
• Ultrasound is useful, but only assesses the bone surface, particularly for pelvic fractures.

Diagnosis - Advanced Imaging

• Nuclear scintigraphy can detect areas not visible on radiographs, highlighting increased bone turnover, which is helpful in detecting pelvic fractures.
• Computed tomography (CT) is valuable for detailed 3D images of various skeletal areas, especially the skull and cervical vertebrae (requiring general anesthesia).
• Magnetic resonance imaging (MRI) is helpful for distal limb fractures if the diagnosis remains unclear.

Criteria for Humane Euthanasia

• Questions arise regarding when immediate humane destruction of a horse with a fracture is indicated.

BEVA Guidelines

• BEVA guidelines provide specific prognoses for different types of orthopaedic (bone) fractures, differentiating between immediate destruction cases and those suitable for second opinion.
• They provide detailed examples that may require immediate destruction.

BEVA Guidelines Summary

• Certain fractures, such as multiple tarsal/carpal bone fractures, compound long bone fractures, adult humeral/radial/tibial/femoral displaced fractures, pelvic fractures (when the horse is recumbent), and comminuted pastern fractures without an intact strut, warrant immediate humane destruction.

Prognosis

• Prognosis depends on factors like the site of the fracture, the size of the horse, the way the fracture is configured (e.g., transverse vs. oblique), the severity of the configuration (e.g., simple vs. comminuted), if the fracture is articular or non-articular, the degree of contamination (e.g., open vs. closed), the degree of contamination, the degree of displacement, and soft tissue damage.
• Consult with surgical specialists early for comprehensive care plans.

Decision Making and Management in the Field

• Aims include pain and anxiety relief, facilitating repair and healing, controlling haemorrhage and wound infection, establishing accurate diagnosis, considerations of referral, and evaluating financial limitations.

Fracture Management in the Field

• Common methods include sedation (using xylazine or detomidine), analgesia/anti-inflammatories (e.g., butorphanol, morphine, NSAIDs), wound management (e.g., clip, clean, debride), antibiotic therapy (especially for open fractures), tetanus prophylaxis, stabilisation, and transport to suitable facilities.

Transportation of the Horse

• Appropriate support should be applied first.
• Transport techniques should be adapted based on the type of fracture (e.g., forelimb or hindlimb).
• Horse ambulances should be used for optimal care during transit.
• Careful handling is crucial, especially during loading and unloading.

Distal Phalanx Fractures

• Distal phalanx fractures in horses often lead to acute, moderate to severe lameness.
• Associated signs include a warm hoof, increased digital pulse (generally only in the acute phase), potential positive hoof testers, and possible DIP joint synovitis (if articular).
• Radiography using a dorsoproximal palmarodistal oblique ("Upright Pedal View") is essential for diagnosis.

Fracture Classification

• Detailed fracture classifications are provided for a better understanding of different types of fractures.

Prognosis of Distal Phalanx Fractures

• Detailed prognosis based on the classification is provided

Treatment of Distal Phalanx Fractures

• Conservative management (box rest, approximately 2-4 months, NSAIDs, and remedial farriery) is usually the initial approach.
• Surgical intervention (e.g., lag screws) may be considered for certain cases, especially articular fractures.

Limb Fractures

• Regional considerations are important in the immobilisation of limb fractures.
• No one technique is optimal for all types of limb fractures within each region.

Principles of Temporary Immobilisation

• Neutralising distracting forces, pain relief, application of counter pressure, and protection of soft tissues are key principles involved in immobilisation.
• Splints should incorporate articulations proximal and distal to the fracture, allowing the horse to bear some weight.

Fracture Stabilisation

• Common methods for stabilising fractures in horses include splints (e.g., Robert Jones bandages, splinted Robert Jones Bandage, dorsal splint and heel wedge, Kimsey leg-saver splint, palmar/plantar board splint), casts (bandage casts), and compression boots.

Robert Jones Bandages

• Specific guidelines are provided regarding the material requirements and procedures for implementing Robert Jones bandages.

Splints

• Information on using and fitting wooden splints and PVC pipe splints is included.

Bandage Casts & Casts

• Fibreglass casting tape application over limb bandages can be used for immobilisation.
• Casts are a good choice for complete immobilisation, involving fibreglass tape and water-activated polyurethane resin which also needs to be kept in warm water while being applied.

Compression Boots

• Compression boots provide limb support in a neutral weight bearing posture and are considered robust, durable, and long-lasting but expensive.

Immobilisation of Zone I

• Specific immobilisation techniques are detailed for Zone I (forelimb and hindlimb), outlining the types of splints and bandages to use.

Zone II - Forelimb

• Fractures in Zone II affect the third metacarpal bone and should be immobilised using a Robert Jones bandage or a combined lateral and cranial splint, along with appropriate cast.

Zone II - Hindlimb

• Fractures, especially any involving the tarsal bones, require careful immobilization with a Robert Jones bandage, caudal splint, and possibly additional lateral splint.

Exceptions: Metacarpal/Metatarsal Condylar Fractures

• These fractures differ from typical Zone I fractures.
• Lateral fractures are more common than medial, and stability, along with appropriate bracing and handling, plays a crucial role.

Zone III Forelimb

• Techniques for this area include fixing the carpus in extension and adopting a caudal splint reaching the elbow, along with dorsal and lateral splints.

Zone III Hindlimb

• Methods used include a Robert Jones bandage, caudal splint reaching the hock, and a lateral splint, along with appropriate cast.

Zone IV - Forelimb

• Fractures involve the humerus, ulna (olecranon), or the scapular neck, complicating immobilization.
• Stabilization is through methods like full limb bandages and caudal as well as dorsal splints, possibly adding a rope around the pastern.

Zone IV - Hindlimb

• Fractures affecting the femur or pelvis are difficult to immobilise as bandages or splints alone are often insufficient due to the added weight.

Pelvic Fractures

• Assessment focuses on pelvic asymmetry.
• Stress vs. traumatic causes should be distinguished.
• The severity of lameness varies.
• Specific types of pelvic fractures (tuber coxae, iliac wing, iliac shaft) have distinct characteristics and treatment approaches.

Pelvic Fracture Diagnosis

• Palpation per rectum, ultrasonography (challenging without substantial displacement), nuclear scintigraphy, and radiography are the diagnostic methods.
• Treatment involves conservative approaches such as cross-tying to minimise displacement.

Prognosis of Pelvic Fractures

• Prognosis is linked to the location affected and any displacement.
• Survival rates are typically between 50-70%.
• Fracture types (such as tuber coxae) typically have good prognoses, while those involving the iliac shaft or acetabulum have poorer ones.

Special Considerations

• Recommendations are given for managing fractures occurring in racehorses to inform any decisions about the horse's use in racing.