Fractures of the lower limbs in calves are quite common and often occur due to trauma during dystocia or handling (Tulleners, 1986a). When presented with a calf with a fractured limb, it is important that you examine the limb in detail to assess if treatment is an option.
In the field, splinting and casting are often the only options for the treatment of a fracture. Splints can be successful in lightweight calves with certain uncomplicated fractures, but casts are stronger and more rigid and are, therefore, often the treatment of choice.
The decision-making process for treatment
Four main criteria need to be met for the successful treatment of a fractured limb in farm animal practice.
1) Establish if there is a fracture and the location of the fracture
Firstly, it is essential to diagnose if there is a fracture and where the fracture is located. Displacements and an unusual increase in limb movement can all be signs of a fracture.
Taking X-rays in two directions is the gold standard to confirm the presence, establish the exact location and determine the severity of a fracture. However, in many farm animal practices, X-ray machines are not available. Nevertheless, a specific diagnosis can often be done with careful inspection and palpation of the calf’s limb.
The most common place for limb fractures is the metacarpus and metatarsus III-IV (St. Jean and Anderson, 2014).
2) Other factors that influence the success of treatment
It is vital to rule out vascular and nerve damage to the limb to establish if a calf is a good candidate for treatment.
In a hospital setting, angiograms can be used to assess if arterial perfusion is functional (Mulon and Desrochers, 2014). Alternatively, in field conditions, vascular damage is indicated by swelling, coldness to the touch and sometimes discoloration of the affected area. Checking spinal reflexes and pain perception and looking for specific signs of nerve damage (such as knuckling of the digits and a dropped elbow with a radial nerve lesion) must be part of a neurological exam of the affected limb.
In field conditions, vascular damage is indicated by swelling, coldness to the touch and sometimes discoloration of the affected area
Other crucial factors for successful treatment are general health conditions like nutritional status and concurrent infectious diseases. In a young calf, good passive transfer will help to limit the occurrence of infectious diseases.
3) The severity of the fracture
For the bone to be able to heal, the bone surfaces need an overlap of at least 50 percent, and movement needs to be reduced as much as possible. Be aware that highly comminute fractures (fractures with more than two pieces) tend to collapse after casting. Long oblique and spiral fractures will override too much when the calf is weight-bearing, which can cause penetration of the skin. Therefore, these types of fractures will need more fixation than a cast alone for successful treatment (Mulon and Desrochers, 2014).
Open fractures in cattle tend to have high levels of contamination, which makes it very difficult to keep infection out. Generally, casts are only indicated for closed fractures. Successful treatments of open fractures with casts have been reported (Tulleners, 1986b), but the actual level of treatment success, the intensity of case management, costs and animal welfare need to be considered and discussed.
4) Care for the animal
Animal welfare and costs are also important criteria when considering lower limb fractures in calves. Even when treatment is straightforward, the calf will need to be confined by itself in a small area for eight weeks. It will need sufficient bedding, food and water, and the cast will need checking for rubbing and discharges daily. In addition, the veterinarian needs to assess the calf and cast regularly.
The calf needs to be able to get up, move around and be weight-bearing while the limb is in a cast to ensure the limb is functional after treatment
The calf needs to be able to get up, move around and be weight-bearing while the limb is in a cast to ensure the limb is functional after treatment; otherwise, these functions will generally not come back after cast removal.
Suitable fractures for treatment
In most cases, the joints proximal and distal to a fracture need to be immobilised for it to stay stable and immobile. This means that the metacarpus and metatarsus III-IV are the most suitable bones to put into a cast. Table 1 shows the different kinds of fractures suitable for cast application (Mulon and Desrochers, 2014).
| Fracture | Explanation of fracture terminology |
|---|---|
| Simple transverse diaphyseal fracture | Fracture is in a straight line, perpendicular to the diaphysis (tubular shaft) of the bone |
| Short oblique diaphyseal fracture | The fracture line is between 30° and 60° relative to the diaphysis of the bone |
| Metaphyseal fracture Salter–Harris Type 1 | The fracture line runs straight across the growth plate, involving the cartilage without affecting the bone. The epiphysis (rounded end of the bone) can be separate from the diaphysis |
| Metaphyseal fracture Salter–Harris Type 2 | The fracture line is at an angle, cutting through most of the growth plate and the metaphysis (area above the growth plate) |
Cast materials
Traditionally, plaster of Paris was used as the casting material. Nowadays, synthetic casting tape such as fibreglass is available and not too expensive. Synthetic casting tape is waterproof and stronger than plaster of Paris, which makes it less likely to fail after application. It is, therefore, the preferred choice.
Application technique
It is important that the padding used between the skin and the casting material protects the skin against pressure sores from the cast. However, padding needs to be kept to a minimum to reduce possible movement of the fractured pieces.
Padding needs to be kept to a minimum to reduce possible movement of the fractured pieces
There are two main methods for the application of padding. The first involves applying felt to areas where there are bony prominences and underneath the dewclaws. The felt needs to fit correctly, be of an appropriate thickness and not stick out. It is kept in place with white tape, and then a double layer of surgical stockinette is fitted around the leg. Casting tape is then applied over this (Mulon and Desrochers, 2014).
The second method is to place cotton or felt underneath the dewclaws and, subsequently, two layers of cast padding on a roll over the whole limb. A lightweight conforming bandage is then applied to keep this in place. Long pieces of tape applied to the skin and conforming bandage at the same time prevent the padding from slipping down.
Final points
- When the limb of a calf is put in a cast, the whole foot must always be incorporated into the cast. This means the bottom of the cast needs to be suitable for walking
- As casts are applied in lateral recumbency, always ensure that the limb is positioned in its natural position while applying the casting material
- Good fracture reduction is necessary to align the fractured bones. This is most easily done by applying a rope above the claws or fetlock (depending on where the fracture is) and the application of traction. Some traction should be retained while the cast is applied to keep the fracture reduced
- Remove the cast and assess the limb every two to three weeks. This helps ensure that the cast is applied correctly, which can prevent deformities. This also allows for the prognosis to be updated for the owner and for animal welfare to be assured
