Information
Editors
Cast Treatment of Lower Extremity Fractures
Long-leg cast
Indications
- Non-displaced fractures of the lower leg
- Rarely in knee fractures (mostly treated with surgery or a hinge orthosis)
Equipment
- Tube gauze, padding, polyurethane foam bandage, 4-6 rolls of 15-20 cm wide plaster or 5 rolls of fibreglass/plastic cast (10 cm wide). Nowadays, mainly fibreglass casts or soft casts reinforced by fibreglass cast are used.
Preparing the cast
- Always have an assistant holding the leg and maintaining the ankle in a 90-degree dorsiflexion and the knee in an about 25-30-degree flexion. NB: The foot must not remain inverted.
- The leg must be in the correct position before wrapping the padding because later flexion of the ankle will make folds in the padding material. Such irregularities will press the skin inside the cast.
- To protect the skin, use tube gauze and put two layers of padding on it from the base of the toes to the upper thigh. Pad the malleolar bones, the knee and the site of the injury especially well. Foam bandage is wrapped on the padding so that the contours of the leg are visible.
- The cast is wrapped on the padding in five equally thick layers and is moulded, changing the supporting grip while proceeding. After the first layer, a splint formed of 4-5 layers of cast is placed on the sole from the base of the toes over the heel. The splint may also cover the full length of the cast; in this case 3-4 layers are enough. Make sure that all toes are free to move. In the proximal end, the cast extends up to the greater trochanter and is supported on it. Round the edges by pulling the tube gauze over the cast.
- In acute injuries or after surgery, the plaster cast is always split with a cast cutter and the leg is supported in an upright position. The cast is closed after 3-5 days with 1-2 rolls of fibreglass. A fibreglass cast is not split.
- If weight bearing is allowed, make the calf stronger and set a heel or a cast shoe.
- Isometric quadriceps exercises should be started without delay.
Short cast boot
Indications
- Stable lateral malleolar fractures (fractures of the medial malleolus and the posterior triangle usually require surgery)
- Medial malleolus fracture in an exact position (anatomic alignment)
- After operative treatment of malleolar fractures
- Foot (Lisfranc) injuries (not in fractures of the II-V toes and not in single fractures of the II-V metatarsal bones)
- Transverse tarsal joint (Chopart's joint) injuries
Equipment
- Tube gauze, padding, polyurethane foam bandage, 4-6 rolls of plaster (width 15 cm for the ankle, 20 cm above the ankle) or 2-3 rolls of fibreglass/plastic cast (10 cm wide). Primarily fibreglass cast is used (see below).
Preparing the cast
- Place a stand under the knee to support the leg.
- Use tube gauze to protect the skin, and place the ankle in a 90-degree flexion (no inversion!).
- Wrap two layers of padding from the base of the toes up to upper calf and add foam bandage on the padding.
- The cast is wrapped on foam bandage leaving the toes free. The knee has to be free to bend. The cast should extend up to the level of the upper head of the fibula (to avoid peroneal nerve injury use enough padding, not a single dent is allowed). Round the edges by pulling the tube gauze over the cast. For making the sole, see instructions given for the long-leg cast (when using fibreglass/plastic cast material, a splint should not be used).
- In acute injuries, the cast is split and the plaster cast is closed with fibreglass after 2-3 days.
- If weight bearing is allowed make the calf stronger and set a heel or a cast shoe.
- In the end, it is good to perform follow-up radiography through the cast. This makes sure that the ankle is in a 90-degree angle and shows the final position of the fractures in the cast. In ankle fractures, it is important to also confirm that the ankle fork is congruent/symmetrical in the mortise projection.
Fibreglass cast
Indications
- Follow-up treatment after a plaster of Paris cast
- In the initial phase, it is also possible to set a split fibreglass cast boot which will be replaced with a closed cast in 2 weeks' time.
Equipment
- Tube gauze, padding, 2-4 rolls of fibreglass cast (width 10 cm, one 7.5 cm wide). 5-6 rolls for a tall boot cast
Preparing the cast
- Prepared similarly to a plaster of Paris cast (i.e., no crepe paper is used); prevention of folds is even more important.
Weight bearing
- Weight bearing with a cast shoe
- The permission to bear weight depends on the fracture, not on the cast material.
Cylinder cast
Indications
- Used in exceptional cases of patellar fractures when treatment with an orthosis is not possible or when the cast is required to secure the outcome of surgical treatment.
- Rarely other knee injuries (dynamic knee supports are becoming more common) or fractures of the upper part of the lower leg or the lower part of the thigh when surgical treatment is not possible.
Equipment
- Tube gauze, padding, polyurethane foam bandage (e.g. Haftan® ) and 6-8 rolls of plaster
- Nowadays made primarily of fibreglass, 4-5 rolls.
Preparing the cast
- Place a stand under the ankle while an assistant supports the leg under the knee.
- Cover the extremity with tube gauze and pad the lower part of the ankle with a few layers of cast padding.
- Padding and foam bandage are wrapped from the malleolar level up to the upper thigh and the plaster is wrapped on these.
- An assistant supports the knee in a 25-30-degree flexion and changes the grip while supporting as the application proceeds to avoid dents. Make sure that the malleolar bones are free and that the ankle is free to move.
- The cast is moulded carefully around the knee and the thigh is supported from the sides to avoid later sliding of the cast.