Bovine Fractures Study Guide

Overview and Clinical Importance

Limb fractures are commonly encountered in bovine practice, particularly in young calves. Cattle are excellent orthopedic patients due to their remarkable bone healing potential, resistance to contralateral limb breakdown and stress laminitis, tolerance for external coaptation devices, and the significant amount of time they spend recumbent. The decision to treat fractures in cattle involves careful evaluation of economic value, treatment cost, fracture location, and prognosis. This guide covers the essential knowledge for the NAVLE examination regarding bovine fracture diagnosis, classification, treatment, and complications.

Epidemiology and Etiology

Fractures in cattle most commonly affect young stock, with etiology varying by age. In neonatal calves, dystocia and improper use of calving chains are the primary causes, particularly affecting the metacarpus and metatarsus. In older cattle, fractures typically result from slipping on hard or wet surfaces, mounting behavior, collisions, or becoming trapped in equipment.

Distribution of Fractures by Bone

Fracture Classification

Classification by Soft Tissue Status

Closed fractures: Skin integrity maintained; account for approximately 86% of bovine fractures. Better prognosis due to lower infection risk.

Open fractures: Skin penetration with bone exposure; approximately 14% of cases. Higher contamination risk, guarded prognosis, and require aggressive debridement and antibiotic therapy.

Classification by Configuration

Salter-Harris Classification in Calves

Physeal fractures are common in young calves, with Type II being the most frequent. The classic calving chain fracture is typically a Salter-Harris Type I or II fracture of the distal metacarpal or metatarsal physis.

Clinical Presentation and Diagnosis

Clinical Signs

Fractures typically present with acute onset severe lameness, non-weight bearing on the affected limb, and visible swelling. Key clinical findings include:

• Non-weight bearing lameness (most consistent finding)
• Swelling and soft tissue trauma at fracture site
• Crepitus on palpation
• Abnormal limb angulation or shortening
• Pain on manipulation
• Recumbency (more common with hindlimb fractures)

Special Considerations by Fracture Location

Phalangeal fractures (P1, P2, P3): Acute lameness; P3 fractures may lack visible swelling and be difficult to localize with hoof testers. Percussion and hyperextension/flexion of digits may reveal pain. Radiography is essential for definitive diagnosis.

Femoral fractures: Animal often recumbent or severely three-legged lame; thigh swelling may be visible in neonates. Can mimic coxofemoral luxation or femoral nerve paralysis.

Pelvic fractures: May present as "knocked-down hip" with pelvic asymmetry; asymmetry between tuber coxae, greater trochanter, and ischial tuberosity.

Diagnostic Approach

Physical Examination

Systematic evaluation should include assessment of neurovascular status (critical for prognosis), palpation for crepitus and abnormal mobility, evaluation of soft tissue integrity, and assessment of contralateral limb. Check for signs of vascular damage: swelling, coldness, discoloration. Evaluate neurological function including spinal reflexes and pain perception.

Radiography

Radiography is the gold standard for fracture diagnosis. Two orthogonal views (minimum) are essential. Key radiographic findings include fracture line visualization, fragment displacement, presence of fissures affecting pin placement, and assessment of soft tissue gas (indicating open fracture or infection). Radiography also guides prognosis by revealing fracture configuration and comminution.

Ultrasonography

Ultrasonography is useful for pedal bone (P3) fractures when radiography is unavailable. Studies demonstrate sensitivity of approximately 93% and specificity of approximately 91% using a 5 MHz linear transducer. Also useful for monitoring fracture healing progression.

Treatment Principles and Methods

Decision to Treat

The decision to treat a fracture in cattle involves weighing four key factors: cost of treatment, success rate/prognosis, economic or genetic value of the animal, and location and type of fracture. Cattle are excellent orthopedic patients due to their bone healing properties, tolerance for immobilization, and recumbent resting behavior.

General Rule for Treatment Selection

Key principle: The higher the fracture location on the limb, the more difficult it is to immobilize effectively. Fractures below the mid-radius or mid-tibia can generally be treated with external coaptation. Fractures proximal to this level require additional support (Thomas splint, transfixation pins) or internal fixation.

Treatment Options

Casting Technique Essentials

Cast Application Steps

• Padding: Apply stockinette and adequate padding over bony prominences
• Immobilization: Cast must include joints proximal and distal to fracture; always include the hoof
• Material: Fiberglass cast tape with polyurethane resin; 3-4 inch for calves, 5-6 inch for adults
• Application: Apply in smooth spiral pattern, overlapping by half each turn; snug but not tight
• Complete before hardening: All layers must be in place before material starts weeping (chemical reaction beginning)
• Seal the top: Roll stockinette down and incorporate into final layer; seal with elastic tape

Emergency Splinting Principles

For field stabilization prior to definitive treatment:

• Splints must be placed over a padded bandage (never directly on skin)
• Splints must extend to ground level to off-load the foot
• Place splints orthogonally (90 degrees apart) except for tibial fractures
• Semi-circular PVC pipes work well for newborn calves with fetlock-level fractures

Treatment by Fracture Location

Metacarpal/Metatarsal Fractures

Prognosis: Excellent for closed fractures with casting. These are the most common fractures and typically respond well to external coaptation.

Tibial Fractures

Prognosis: Fair to good with appropriate treatment. Thomas splint-cast combination or TPC typically required. Overall survival rate approximately 45% in some studies.

Femoral Fractures

Prognosis: Guarded. Closed repair seldom succeeds. Internal fixation required for breeding/high-value stock. Common in neonates from dystocia (breech presentation with stifle lock).

Treatment options: Intramedullary pins (neonates), interlocking intramedullary nails (IIN), double plating (heavier animals greater than 100 kg), ESF/IM pin tie-in (cost-effective alternative).

Phalangeal Fractures (P1, P2, P3)

Complications of Fracture Healing

Prognosis Summary by Location