Department of Orthopaedic Surgery
Stellenbosch University

Page 2 Specific Casts   Home   Next Page >>

Plaster Casts and Splints

Upper extremity casts

Casts on the upper extremity may extend above the elbow or be limited to the forearm and hand. In either case, the cast should be trimmed along the line of the knuckles on the dorsum and obliquely across the proximal flexion crease of the palm on the volar side to allow unrestricted motion of the fingers.

Three points of contact should be mould ed into the cast. These points reverse the direction of displacement and hold the fracture fragments reduced. A contact point should not cross a joint. Take care to ensure these contact points are smooth, make them wide, and gradual, with the base of your thumb or plam.Th ese points should not cause discomfort to your patient.
3 points of contact must be moulded into a plaster
Three points of contact should be mould ed into a plaster
Make the cross-section of your forearm cast oval. Otherwise falling in may result in possible cross union

A hole should be cut out around the thumb just large enough to allow unrestricted motion. – This means that the distal end of the cast should extend to the level of the MP joints The edges of this thumb hole must be carefully everted, so that the sharp edge does not cut the skin. Occasionally, the thumb may be included in the cast, as in treating scaphoid fractures.

Pillow slip method of elevating an upper limb
Pillow slip method of elevating upper limb. Turn the slip half inside out,along its length as shown. Use this sling to suspend the upper limb vertically from a drip stand, so that the fracture is just above the level of the heart.
Post manipulation immobilisation: If the patient has to lie in bed the pillow slip method of elevation can be used.

Lower-Extremity Casts

Bucket method of reducing a tibia fracture The first plaster is best applied with the knee bent 90 degrees over the end of the table. Traction is then applied by an assistant, (or a bucket of water as depicted here) Make sure the rotation, as well as the alignment is corrected. Velband is then applied, and the pop applied to the lower leg. The knee is then straightened to 15 degrees, and the above knee POP completed.

Long-leg casts may be applied with the knee flexed or extended, but if weight-bearing is to be allowed, the knee should be neutral or in 5° of flexion.
Application of padding
Application of padding
Application of a BK POP
BK Pop
Take up slack
by making tucks in the plaster bandage
The cast should be trimmed in line with the metatarsal heads on the plantar aspect and at the base of the toes dorsally. The fifth toe must be entirely free; this is a common site for a plaster sore. Perkins stated that it is most important not to immobilize the forefoot in varus, and he left the metatarsal heads free to bear weight. If a toe plate is used, the metatarsophalangeal joints must not be held in hyperextension. In fractures of the lower third of the tibia, dorsiflexion of the foot frequently causes angulation of the fracture. It is quite permissible under these circumstances to immobilize the foot in plantar flexion, although in fractures of the ankle this would be proscribed. When the foot is immobilized in plantar flexion and a walking heel is applied, the contra lateral shoe should be raised to equalize leg lengths.

Many orthopaedic surgeons reinforce their casts by applying splints to the posterior aspect of the cast. This adds weight without adding much strength. The same amount of plaster applied anteriorly as a fin strengthens the cast immeasurably, making fracture of the cast at the ankle virtually impossible

Points in applying above knee cast

  1. Proximal end – as high in the groin as possible

  2. Distal end – To MP joints of foot

  3. Knee in 5 to 15 degrees flexion

  4. Foot in at 90 degrees to tibia

Hip and Shoulder Spicas

Avoid the use of hip and shoulder spicas in adults. They are more readily tolerated in children. Make sure there is someone at home during the day to care for the patient you discharge in a spica. In the past, patients were frequently sent home in hip spicas to make space in hospitals. In their home environment, if no one cares for them, they may lie unturned, soaking in their own urine and feces and manufacturing immense decubitus ulcers. We have seen a paraplegic woman with a fractured spine transported in a double hip spica, who on arrival had bone showing over both iliac spines, both greater trochanters, and her sacrum
Spica Cast
Spica Cast
A one and a half spica cast. The leg portions are reinforced with a piece of wood. Beware also of "registrar's" corner - the portion behind the buttocks often neglected and this can cause breakage
It is hazardous to place patients in spicas when they lack sensation, and it is only under the most unusual circumstances that we would now advocate the use of the hip spica in adult fractures; however, they may still play a role in children's' fractures.

To reduce the weight of these casts and make the patient more comfortable, a substantial window should be cut out over the belly. This portion of the cast contributes nothing to its strength, but the window should always be circular or oval and never rectangular, because corners act as stress risers. This means that it is best cut with a knife. If one waits too long, cutting the hard plaster can be tedious. The task is made easier by outlining the window with the knife and then making a cross with the plaster saw within the circle. The free corners may then be pried up and the cutting of the circumference completed with

Older orthopaedic surgeons at some time or other in their career have been embarrassed by the disconcerting habit that spicas have of breaking at the hip. This is sometimes caused when a triangular area, commonly known as the "amateur's corner," at the junction of the limb and trunk does not receive its fair share of the plaster. It also results, as Strange pointed out, from the juncture of the body and leg being an open section and thus very much weaker than the circular portions of the cast. To strengthen this weak point, fin-like reinforcements are applied anteriorly, posteriorly, and laterally, much in the same way that a walking cast might be reinforced apply a new cast.