70. Plaster

From Primary Surgery

70.1 Plaster, and the equipment for it

Fig. 70-1 PLASTER EQUIPMENT. Use this equipment to make standard casts, such as the long leg and short leg walking casts- The indications for each of them and the details as to how you should apply them are critical.

Plaster of Paris is ideal for treating some fractures. But you must apply it skilfully, and only on the proper indications. If you apply a plaster cast carelessly, it can cripple a patient forever, and you may even have to amputate his limb. Use a plaster cast: (1) to immobilize bony fragments in the right position, (2) to protect his limb while his bones unite, (3) to make him comfortable. But casts have serious disadvantages. They can obstruct his circulation, they can cause pressure sores (70.3), they are heavy and inconvenient, they stiffen joints, and if you leave them on too long, the cones inside them become weak and osteoporotic.

Use standard casts, such as the long leg and short leg walking casts (81.3). The indications for each of them and the details as to how you should apply them are critical. These critical details include the position of the patient's limb, how far up and down it the cast should go, where you should put the padding, and the rule that a patient must exercise his muscles inside his cast. So follow the details we give exactly, and see that your assistants do so too. There are other ways of doing things, but you will not know which they are, and we do not have the space to describe them. Vary the methods we describe only if you have good reasons for doing so. For example, never apply any cast at the extreme range of movement of a joint. Pressure on the joint surface will make its cartilage necrose and cause osteoarthritis later.

EXERCISE THE MUSCLES INSIDE A CAST

• PLASTER BANDAGES, normal, slow setting, best quality, 10 cm, 15 cm, and 20 em wide. Good quality plaster bandages make the strongest casts and poor ones are a mistake. If you use them, you will need twice as many, and the cast will be twice as heavy. If necessary,

you can make plaster bandages locally from powdered plaster of Paris and rolls of gauze bandage. Plaster bandages are cheaper if you buy them as a long roll which you can cut off in the lengths you require.

• CREPE BANDAGES Many hospitals do not have these, so we have indicated alternatives when possible. You can use a plaster bandage instead

of a crepe one to hold plaster slabs, but this is far from satisfactory.

• STOCKINETTE, woven tubular, orthopaedic, various widths, three rolls of each width. Use this in suitable widths for the finger,

the arm, the leg, and in small quantities for the trunk. If you thread it on to the limb before applying plaster, it will stop the plaster sticking to the hairs on the patient's skin, and will make casts and slabs more comfortable. It is not a substitute for adequate padding. If you don't have it, use ordinary cotton bandages, or a single layer of expanded cotton wool. Cotton bandages will also make a stronger cast.

• PADDING, cotton wool, orthopaedic, ten rolls only. If you do not have this, cut a roll of ordinary cotton wool into smaller rolls 10

or 15 cm wide. Unroll them, leave in the sun, and let them expand. Then split them into four or five layers of the thicknesses you want, and roll them up again, ready for use. Each of your new rolls of expanded cotton wool will be the same size as the original one, but it will contain more air and collapse down more easily when you roll it on to a limb and cover it with plaster.

• STIRRUPS, locally made. These support a patient's leg when he wears a walking cast. The cross pieces at the top are thin so that they bend easily to fit the shape of his leg and spread its weight through

the cast.

• PLASTER SHEARS, Lorenz, 380 mm, nickel plated, one only. These large shears will open the strongest casts, but are unnecessary

if you have an electric cast cutter.

• PLASTER SHEARS, Guy, with shaped bows and flattened probe end, 250 mm, nickel plated, one only. These shears are smaller and easier to use for removing small casts than the Lorenz shears. If you don't have them, use ordinary pliers.

• PLASTER KNIFE, Esmarch, solid forged, two only. Use this for splitting circular casts after they have hardened; sharpen it on a stone. If necessary, you can use almost any knife.

• PLASTER SAW, Bergman's , hand, one only. If you don't have electricity, you will need this.

• PLASTER CAST SAW, electric, oscillating, with four extra blades, 44 mm and 64 mm, state voltage, one outfit only. These

will be useful if you have electricity; unfortunately most plaster saws have a short life.

• PLASTER CAST SPREADER, one only. When a cast has been split, this will spread it, so that you can remove it from the limb.

• PLASTER CAST BENDING FORCEPS, Boehler, one only. These are large pliers for bending the edges of a cast and opening it.

• PENCILS, INDELIBLE, for writing on a cast, six only. When you apply a cast write on it the date you applied it and the date you expect to remove it, together with a sketch of the fracture inside, as in Fig. 70-6. If the plaster is still wet, you can use a ball pen, but an ordinary pencil is unsatisfactory. An indelible pencil containing a water

soluble blue dye is ideal.

70.2 Slabs or a circular cast?

You can apply plaster, either as a slab covering part of the circumference of a limb, or as a circular cast all round it.

You can put ,a slab on one side of a limb, or on both sides, and hold it in place with a crepe bandage. The advantage of slabs is that they allow a limb to swell without obstructing its circulation (70.4). As the swelling subsides, the elasticity of the crepe bandage will hold the slabs against the limb without letting them become loose. If you don't have a crepe bandage, you can use a few turns of plaster bandage, but remember: (1) to split it as you would a circular cast (70.3), and (2) to renew it as it becomes loose. Slabs are useful for the initial treatment of a severe fracture and are safer than circular casts.

But slabs don't immobilize some fractures securely enough. Slabs are weak, and easily break at the elbow or the knee. So for many fractures you have to use a circular cast which will hold the fragments in place more securely, and be stronger. But if you apply a circular cast unwisely, it will obstruct the circulation in a limb, and as the swelling subsides, it will become loose. So with a circular cast you have two choices, either: (1) wait for most of the swelling to go, before you apply it, or (2) renew it as the tissues shrink.

70.3 Splitting and spreading a cast

Fig. 70-2. ALWAYS PAD THESE PARTS OF A LIMB, or a cast will be uncomfortable and pressure sores may form- Protection of the com mon peroneal nerve as it winds round the neck of the fibula is especially important

Always pad the prominent bony parts of a patient's limb, shown in Fig. 70-2, or the cast will cause pressure sores. You can choose whether or not you will put a layer of cotton wool or orthopaedic felt over the rest of his injured limb. Padding a cast completely: (1) makes it less likely to obstruct his circulation, (2) compensates to some extent for shrinkage of his limb because the padding expands a little as his limb shrinks, (3) makes the cast less likely to cause pressure sores, (4) makes it easier to remove, and (5) makes it easier to wedge. The only disadvantage of a padded cast is that it does not hold the bony fragments quite as still as an unpadded one. Be safe and pad all casts. The only exception is a cast for the scaphoid (Fig. 74-10).

If you have decided to apply a circular cast, the next question is whether or not you should split it, so that it can open as the tissues under it swell. If you put a circular cast on a freshly reduced fracture without splitting it immediately, the cast may restrict the swelling of the tissues, increase the pressure in the limb, obstruct its circulation, and cause either ischaemic gangren e needing amputation, or the compartment syndrome followed by Volkmann's ischaemic contracture (70.4). This can happen even if ischaemia lasts less than an hour, and is a particular danger with fractures of the forearm and lower leg. It is not a danger in casts for the scaphoid or Bennett's fracture, so there is no need to split these casts. An unsplit circular cast is especially dangerous if a patient already has signs of circulatory impairment (70.4). A hundred unsplit long leg casts may give no trouble, but the hundred-and-first may obstruct a patient's venous return, cause gangrene, and require that his leg be amputated. When you make rounds the following morning, it may be too late! Gangrene or Volkmann's contracture may have started at midnight!

Splitting a cast with a scalpel will not destroy its capacity to hold the bony fragments, and is easy if you do it while a cast is still soft. Spreading a split cast with a blunt object such as a screwdriver, so that its edges open, is a separate procedure. It is only necessary on the rare occasions when the circulation to a limb is impaired.

ALWAYS SPLIT THE FIRST CAST ON FRACTURES OF THE FOREARM AND LOWER LEG

70.4 Catastrophes with casts

Fig- 70-3 SOME PREVENTABLE DISASTERS- A, a pressure sore. B, Volkann's ischaemic contracture of the hand. C, Volkmann's ischaemic contracture of the leg.

Two disasters can befall the circulation of an injured limb. An unwisely applied cast can cause both of them: (1) If its circula - tion is completely obstructed, the limb becomes gangrenous, so that all its tissues die, including the skin. (2) If pressure builds up in a tight space, such as a fascial space, the compartment syndrome may develop, followed by Volkmann's ischaemic constructure.

The compartment syndrome is caused by the partially ischaemic muscle swelling, squeezing out its own blood supply becoming hard and partly necrotic, and then slowly fibrosing over several months. As it does so, it strangles the vessels and nerves of the limb. The patient's skin remains intact, and although its nutrition may be impaired later, it does not become gangrenous. Volkmann's ischaemic contracture is the final result. This is usually an anaesthetic, crippled, clawed, forearm. But it can also be an ankle in extreme equinus, with flexion of its midtarsal joint and dorsiflexion of its MP joints and toes. Volkmann's contracture is one of the ultimate orthopaedic disasters, because it cripples for life, it cannot be adequately treated, and it is almost always preventable!

In its less extreme forms Volkmann's ischaemic contracture is more common than most people think. It may only show itself later as a stiff foot, or a very stiff hand that gradually begins to develop severe contractures during the months that follow the injury.

A patient's forearm muscles are most commonly involved by Volkmann's ischaemic contracture, and occasionally the muscles of his lower leg, but never by the muscles of his upper arm, or his thigh, which are less firmly enclosed in fascia. Usually, the tight fascia of his forearm or leg is enough to restrain the swollen tissues and start the syndrome, but a tight bandage (including an Esmarch bandage), or a tourniquet, or gallows (78.2) or extension traction (78.3), or an unsplit cast can all precipitate it. Although a layer of cotton wool between a patient's skin and the cast reduces the risk, any cast all round a limb is a potential source of disaster. Most cases occur in the forearm of children following forearm fractures or supracondylar fractures (72.8). Some follow fractures of the tibia (81.14), and a few follow injuries to the thenar muscles, or dislocations of the elbow (72.4) or knee (79 .8). Occasionally in adults, and very rarely in children, there is sot tissue injury only with no fracture.

Correct management will usually prevent ischaemia, but always be watchful for the early signs (55.3); these are pain, paraesthesiae, pallor, and paralysis. The presence of a peripheral pulse does not exclude the compartment syndrome- The critical symptoms symptoms are the patient's inability to use the muscles of his limb, and pain. The ordinary pain of an immobilized fracture is moderate and improves. Ischaemic pain is more severe and gets worse during the first few hours after an injury. Pain after 48 hours is more likely to be caused by infection.

A well applied circular cast should reduce the pain of a fracture. If a patient, especially a child, complains of pain, take his complaints seriously, it is probably due to: (1) pressure on a bony point which may only subside as his skin erodes away, or (2) ischaemic pain which you must relieve. Pain is not an indication for aspirin or pethidine, it is an indication to find out why there is pain, and to split, window or renew the cast. So, never apply a circular cast to a patient who is unconscious from other injuries, and so unable to complain of pain. He may develop the compartment syndrome only too easily.

VOLKMANN'S CONTRACTURE-A PREVENTABLE CATASTROPHE Use procedures, particularly slabs and a crepe bandage or a split cast, which will make the syndrome less likely.

Identify the patients at particular risk and examine them frequently. Record your findings carefully, and note at what time you made them-

Watch for pain, paraesthesiae, pallor, and finally paralysis, and teach your staff to do the same.

Check the sensation of the nerves in the involved area using two point discrimination, or a pin . I n injuries of the forearm, test for pain on passive extension of the fingers. Test the strength of all involved muscles. Feel the compartment for tenderness and tenseness-

CAUTION ! Remember that a normal pulse does not exclude the compartment syndrome.

TAKE THE COMPLAINT OF PAIN UNDER A CAST SERIOUSLY

70.5 Make your own plaster bandages

This is almost a lost art, but if you can make plaster bandages yourself they will be a tenth the price of those you buy. The difficulty is that the powdered plaster tends to fall through the bandage. The trick is to make the bandage just damp before you cover it with plaster. This will help the plaster to stick to the gauze, without destroying its capacity to set later when it is thoroughly wetted in the normal way. 'Home made' bandages are not so convenient, and take longer to set, but the economy may be worth it.

MAKING PLASTER BANDAGES

MATERIALS Medicinal plaster of Paris (dried calcium sulphate BPC) is best, but you can use builder's plaster of Paris. Buy it by the kilo and keep it dry. Ordinary wide gauze bandages.

METHOD Take a gauze bandage, wet it, and squeeze it as dry as you can- it will now be only just damp and will hold the dry plaster in the next stage.

Rolls. Open the roll of damp bandage, lay a length of it flat, and sprinkle it lightly with powdered plaster- Sprinkle it from your hand, or with a sprinkler. Roll it up as you cover it.

Slabs. Double the bandage backwards and forwards as you cover it.

Dip the prepared rolls or slabs in water and use them just as you would commercially made ones.

Use them that day or store them in an airtight tin- Don't try to make slabs with preloaded bandages.

70.6 Plastercraft

Fig. 70-4 WETTING A PLASTER BANDAGE. Hold the bandage in your right hand- Unwind it half a turn, hold it with your left hand, and put both hands in water. leave the bandage under the water for about 5 seconds until the bubbles have stopped. Hold it gently, so that water enters all its layers. Then, holding one end of the bandage in each hand, take it out of the water, and twist it gently. This will remove excess water, and yet keep the powdered plaster in the bandage. Don't wring it out, or squeeze it, because this will leave it too dry to make a good cast.

Using plaster skilfully is a craft worth learning. A poorly applied malleolar cast, for example, can make it impossible to reduce an ankle fracture. A really critical cast can mean so much to a patient that you should try to apply it yourself. Less critical casts can be applied by an assistant, but only provided you train him carefully and continually supervise him. Ways of making each particular cast are described later, so here are some of the points of technique which apply to all of them.

BASIC PLASTERCRAFT

For all slabs and casts, get everything ready before you wet the plaster bandages. So put stockinette on the limb, or cut and roll a layer of cotton wool directly on to the skin- Fold and trim the slab, and have your assistant ready.

Use 15 or 20 cm bandages wherever possible. Cold water is usually best, but hot water makes them set faster, so adjust the temperature to your needs.

SLABS

Take a dry bandage of suitable width, and use its loose end to measure the required length of the slab. Lay this length of bandage on a table and then double more bandage backwards and forwards over it until you have enough layers to make a slab of the right thickness. Usually, 5 to 10 layers are enough- if necessary, fold the bandage double.

Hold the dry slab in both hands, and dip it in water. Wait for the bubbles to stop, remove it, gently squeeze it, and quickly smooth it out on a flat surface. This will remove the bubbles from between the layers of bandage, and prevent them separating later to weaken the cast.

Apply the wet plaster slab to a single layer of cotton wool, or to a tube of stockinette. Hold the patient's limb in the correct position and smooth out the slab.

CAUTION ! Don't let a plaster slab cover more than two thirds of the circumference of a limb, or it will become so nearly a circular cast that it may obstruct his circulation.

CIRCULAR CASTS

Pad the patient's bony points with particular care in all casts, as in Fig. 70-2, especially if he is thin. Be sure to pad well around his knee and his heel. Then pad the rest of his limb- If you are fortunate enough to have tubular stockinette, thread this over his limb, leaving it long enough to extend several centimetres above and below the cast. if necessary, cut a hole for his thumb. if you have no stockinette, wind ordinary cotton bandages on to his limb.

Use special orthopaedic padding, or ordinary cotton wool expanded as in Section 70.1. Roll this smoothly over his whole limb, evenly with no folds or lumps, and without obscuring the shape of the limb. Don't pull it tight or it will tear. You may need 2 or 3 layers to build up a thickness of about 1 cm. Put extra padding over bony prominences. Apply it from well above to well below where the cast will end.

CAUTION ! (1) Don't apply so much padding that the patient's limb is able to move about freely inside the cast, as if it were inside a boot. (2) if there is a wound on his limb, put the padding on loosely, it may become wet with blood, contract, and impede the circulation.

Roll on the wet plaster bandage without lifting it off his limb, pressing each fold firmly with the base of your thumb, so that most of the tension is transmitted to the middle of the bandage, and not to its edges, where it might cause a sharp ridge. The tension you need will vary with the thickness and elasticity of the padding.

CAUTION ! (1) The correct tension is important or the cast will be loose. (2) The inside of the finished cast must be smooth, because ridges may cause sores. (3) Never pull a plaster bandage tight.

Apply each turn slowly, settle it carefully in position, and join it to the turn below by smoothing it with your hands to remove bubbles. Let it follow the way it wants to go. Leave about 3 cm between turns. Apply it as a spiral without reverses, and when you have to change its direction, make a quick tuck, and smooth it out. Don't twist the whole bandage, or attempt 'figures-of-eight, or apply two turns in exactly the same place- except at the ends-

While you are applying one roll of plaster, ask your assistant to wet the next one- Bandage from one end to the other, and back again, making the cast slightly thicker at its ends, where it will be most likely to fray- Don't build up its thickness over the fracture site, where extra thickness will be useless. Trim its edges while they are still wet, not after they have dried. Bind the ends of the stockinette over into the cast with the last few turns of bandage. This will make it smooth and strong.

CAUTION ! (1) Don't press on a cast with your fingers or thumb while it is hardening, or they will leave a swelling inside it which will cause a pressure sore. (2) For the same reason don't let a cast, especially a cast over the heel, rest on a hard surface while it sets.

A large cast may not be completely dry for 72 hours, and will not be fully strong until then.

Alternatively, start by placing a slab of 4 thicknesses of bandage each side of the limb to strengthen it. Or, incorporate such a slab between layers of bandage.

If you want to strengthen a cast, l et the cast dry thoroughly over the next day or two, then add morte plaster. Wet plaster bandages stick to dry plaster better than they do to damp plaster.

SPLITTING A CAST

The cast must be padded, or you will cut the patient as you try to split it!

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70.7 Windowing casts and wedging them

Windows If a patient has an open fracture, a soft tissue injury, or osteomyelitis, you may occasionally need to make a window in his cast, so that his lesions can be dressed. Fortunately, most wounds and sinuses don't need a dressing, because plaster readily absorbs pus and blood. Avoid a window when you can because: (1) if a patient walks about, his tissues may swell and herniate through it, so that his wound will not heal, and (2) windows which are not closed and strengthened can weaken a cast so much that it bends with each step he takes.

Wedges - If a patient's fractured forearm or lower leg is angulated inside a cast, you can straighten it in two ways, provided the fragments have not yet united: (1) You can open or close a wedge in the cast. This is not as easy as it looks because you may make a wrinkle inside the cast which will cause a pressure sore. So wedging needs care and skill! (2) You can wait until his fracture is healed enough not to displace, but is still soft enough to be bent. This is 3 to 6 weeks after the injury in an adult, and sooner in a child. You can then remove the old cast, straighten the patient's limb under anaesthesia, and apply a new cast. If you don't have X-rays, always use this method. Changing a cast is safer than wedging it, but if you are very short of plaster you may have to wedge it. Opening a wedge is easier; it lengthens a cast slightly, and if the fragments are overlapped, it helps to distract them. Closing a wedge by cutting a piece out of a cast and then closing up the gap is more difficult, and is less often necessary. It closes up the fragments a little, so it is useful if they are distracted.

AVOID WINDOWS IF YOU CAN DON'T LET WEDGES CAUSE PRESSURE SORES

WINDOWING A CAST

Fig- 70-7 ALTERATIONS TO A CAST. A, if a cast is pressing on a patient's heel, you can open it with a saw, and then repair the cut with plaster bandages. B, to E, the easiest way to make a window is to put some dressings over the lesion, make the cast, saw off the bulge, and then repair the cast. Kindly contributed by John Stewart.

Make the windows as small as is conveniently possible, as in Fig. 70-7- Put a firm ball of cotton wool over the lesion where you want a window, and make the cast over it. While the cast i s still soft, hold a knife parallel to the patient's skin, and cut off the swelling over the wool, so as to make the window. Or, cut a square hole in a dry cast with a plaster saw. Prevent the tissues of the lesion herniating through the window by raising the limb and by applying a firm pressure dressi ng through the window. This acts like a piston in a cylinder and helps to prevent herniation. Dress the wound and plaster over the window to strengthen the cast.

WEDGING A CAST

Fig. 70-8 OPENING A WEDGE- Obtain some small blocks of wood to hold the wedge open. Cut through the whole circumference of the cast except for 2 or 3 cm on its convex side, so as to leave a hinge on which it can bend (A, and B). Make the cut about 2 cm proximal to the fracture (C), so that if there is a wrinkle inside the cast, it will not be directly over the fracture, where it may erode the skin. Use a saw or plaster knife. Cut down to the padding, and not into the limb! Carefully bend the cast the way you want it- If necessary hold it open with a block of wood (D), but make sure that the block is clear of the skin. Then repair the cast with a few turns of plaster bandage (E). Xray the limb to check alignment Kindly contributed by Peter Bewes.

Study the X-rays and plan the geometry of what you intend to do carefully. Draw a line round the cast where you want to cut.

OPENING A WEDGE is better than trying to close one, because you are less likely to make a wrinkle inside a cast that will cause a pressure sore. Do this as in Fig. 70-8.

Fig. 70-9 THE GEOMETRY OF WEDGING. A, the angulation that requires correction. B, if the wedge is far from the fracture a small movement will correct the displacement. B, if the wedge is near or over the fracture, a larger movement is necessary. Kindly contributed by Peter Bewes.

CLOSING A WEDGE On the side of the cast which is to be made concave, mark out a wedge about 1 to 3 cm across at i ts widest part. Cut out the wedge, and gently bend the cast so as to close the wedge. Repair the cast with some turns of plaster bandage. X-ray the limb to check alignment. I f more than one wedge is needed in different planes, replace the cast-

CAUTION! Wedge a limb, especially an arm, with care-it can precipitate Volkmann's ischaemic contracture. Watch the circulation in the limb carefully afterwards.

70.8 Chinese wooden splints

CHINESE WOODEN SPLINTS

INDICATIONS Some fractures of the upper limb. You can use splints made of strips of wood padded with paper and cloth for fractures of the humerus, radius, and ulna, and for extension fractures of the wrist. There is no evidence that they are better that plaster casts, but if you don't have plaster, you may find them useful. Wooden splints are light, tenaceous, elastic, radiotranslucent, permeable to the natural moisture of the skin, and can be moulded to the shape of the limb.

CONTRAINDICATIONS (1) Open fractures. (2) Severe bruising. (3) Severe soft tissue swelling. (4) Signs of peripheral circulatory insufficiency. (5) Nerve injuries.

MATERIALS (1) Make thick cloth bandages 1-5 to 2 cm wide from two layers of calico or four layers of bandage sewn together. (2) Make paper or cotton wool pads. These must be absorbent and soft and elastic enough to mould easily to the shape of the limb. (3) Thin pliable strips of wood or bamboo.

METHOD Bandage the patient's limb- Place four or five layers of pads outside the bandages and fix them there with strips of adhesive tape. Outside these place the wooden splints. Bind them in place with about four strips of cloth. Take a check X-ray- Raise the limb and monitor its circulation carefully- if the fracture displaces or the paper pads shift, adjust them immediately-

DON'T FORGET THE PATIENT AFTER YOU HAVE APPLIED THE CAST

Fig- 70-10 CHINESE WOODEN SPLINTS. You can use splints made of strips of wood padded with paper and cloth for fractures of the humerus, radius, and ulna, and for extension fractures of the wrist. Kindly contributed by Cai Ru Bin.

70.9 Traction

To exert traction is to pull. You can use traction: (1) to pull fractured bones into place to begin with, or (2) to keep them moderately immobile until they have united, or, (3) to do both these things, one followed by the other. To apply traction successfully you will have to find some way to grasp a patient's limb safely, for several weeks if necessary. There are two ways you can do this: (1) You can stick adhesive strapping to his skin (skin traction). (2) You can pass a Steinmann pin, a Denham pin, or Kirchner wire through his bone (bone traction). Cord has then to be attached to the strapping, pin, or wire, passed over a pulley, and fixed to a weight. The weight may pull the patient out of his bed, so you usually need to exert countertraction by raising the foot of his bed. One of the main purposes of traction is to allow a patient to exercise his muscles and move his joints, so make sure he does this. Traction takes time to apply and manage, but it can easily be managed by assistants-if you teach them!

Traction is mostly useful in the leg. In the arm it is uncomfortable, inconvenient, difficult to maintain, and frustrating for the patient. For all these reasons arm traction is only useful in rather exceptional circumstances. Elaborate kinds of traction, such as that of Hamilton and Russell for the leg, require equipment you are unlikely to have, so we have only described the simpler kinds here.

PATIENTS IN TRACTION MUST EXERCISE

TRACTION METHODS SUMMARIZED

Fig. 70-11- A SCALE OF TRACTION WEIGHTS showing the range of weights needed for various fractures. Adjust them: (1) to the patients's build, and (2) during the course of treatment.

ARM TRACTION METHODS

FOREARM TRACTION Adhesive strapping is applied to a child's forearm when his elbow is so swollen from a supracondylar fracture that it cannot be reduced immediately (72.6, Fig. 72-11)- Uncommon.

CAUTION! Don't let the strapping interfere with the circulation in his hand.

SKIN TRACTION FOR A FRACTURED HUMERUS is only necessary when a patient is confined to bed (Fig. 71-16). Rare.

OLECRANON TRACTION A Kirschner wire or a small Stein. mann pin is passed through the olecranon for some lower humerus fractures (Fig. 72-14). This is the preferred method of treating comminuted supracondylar fractures in adults- Uncommon.

METACARPAL TRACTION A Kirschner wire through the first two metacarpals is used for for some forearm fractures, especially if the circulation of the forearm is impaired so that you cannot apply skin traction (Fig. 70-13). Rare.

LEG TRACTION METHODS

'90 - 90 TRACTION' i s useful when the proximal fragment of a fractured femur is sharply flexed. A Steinmann pin is put through the supracondylar region of a patient's femur, or his upper tibia, and his hip and knee are flexed to 90° (77.12). Uncommon.

GALLOWS TRACTION The legs of a small child with a fractured femur are suspended from a bar with adhesive strapping (78.2). Very common.

EXTENSION TRACTION Adhesive strapping is used to treat fractures of the femur in an older child or teenager with his knee extended. Also useful for some fractures of the neck of the femur (78.3)- Very common.

PERKINS TRACTION An upper tibial pin is used to ireat most fractures of the femur in an adult. The patient's knee is flexed and he exercises it (78.4). Very common.

BOHLER-BRAUN TRACTION using a special Boehler-Braun frame is useful for some supracondylar fractures of the femur (79.13). it can also be used for other fractures, especially those of the tibia (79.3), but we describe better methods. Uncommon-

DISTAL TIBIAL TRACTION A pin through the distal tibia is used to treat some fractures of the proximal tibia (80.5). Fairly common.

CALCANEAL TRACTION A pin through the calcaneus is used to treat some tibial fractures (81.12, Fig. 81-10). Fairly common.

The purpose of traction is to reduce overlap and bring the displaced bone ends together-not to pull them so far apart (distract them) that they cannot unite! So: (1) Check the length of a patient's injured limb by measuring it, or with X-rays, and adjust the traction accordingly. (2) Vary the traction you apply to the needs of the patient-small patients need less weight than large ones. Don't apply too much traction, and be prepared to adjust it. To begin with you need to apply more traction than is necessary later, when the soft tissues have stretched. For example, for femoral fractures you may need to apply 15 kg to start with, and then reduce it kilo by kilo on the following days.

Ideally, traction should be checked with X-rays, but unfortunately the BRS X-ray machine (1.13) is not portable, and you will probably not have a machine which you can take to the wards. The solution is to have a few beds with large castors which you can wheel to the X-ray department without taking down the traction.

Applying traction to a cast is dangerous because the skin through which pressure is applied is likely to necrose. The only safe way to apply traction to a cast is to pass a pin through the patient's bone and to incorporate this in the cast. Never apply traction to a plaster boot without a proximal tibial pin in place, because it too easily causes pressure sores on the dorsum of the foot.

ADJUST THE TRACTION CAREFULLY

Fig. 70-12 EQUIPMENT FOR BONE TRACTION- Both the handle and the hand drill are cannulated so that a Kirschner wire can pass right through them and be held close to the skin- If you don't have any other kind of drill, use an ordinary carpenter's drill.

• STRAPPING, traction, adhesive, 50 mm x10 mm, six rolls only. This is elastic across its width, but not along its length. If you

don't have it, use ordinary zinc oxide strapping. 'Elastoplast', which is elastic in both directions is useless.

• PIN, Denham, (Denham threaded Steinmann pin), stainless steel, 4 mm, tapered, self tapping, with long coarse screw thread, triangular shank, packet of 5, two packs only. This is

the ordinary Denham pin, but made with a triangular shank. If possible, buy the kind with a long length of thread which will grip both cortices of the tibia.

• PIN, Steinmann, triangular shank, stainless steel, trocar pointed at one end, (a) 2x180 mm, (b) 3x180 mm, (c) 4x180 mm, six only of each size. The small size is for the olecranon and the larger ones are for the tibia.

• HANDLE, with Jacobs chuck, 4 mm capacity, and key attached by chain, fully cannulated, stainless steel, one only. This is an ordinary drill chuck in a handle. This chuck has three jaws, and although it is intended for Kirschner wire and for pins and nails

with triangular shanks, you can use it with square shanks. It will not grip the round section of a pin.

• STIRRUPS, Boehler, for Steinmann pins, with rotating swivel fixation pieces, (a) 102x89 mm, three only. (b) 165x144 mm,

three only. (e) 241x152 mm, five only. These stirrups can be used for Steinmann or Denham pins. The small ones are for the calcaneus and the olecranon and the large ones are for the tibia. If you don't have these stirrups, take a wire coat hanger and bend it to shape, or tie the cords over corks as in E, Fig. 70-14.

• PIN MOUNTS, Thomas, stainless steel with rotating collar for Perkins traction, four pairs only. These are much the best mounts for Perkins traction. If you don't have them, you can make them by cutting a Boehler stirrup and bending the wire. The hooks must rotate freely round the collars.

• STIRRUPS, for wire traction, adjustable, tensioning, Gissane, 216 mm, with two cord hooks, two only. These are for exerting tension on Kirschner wire. They are more expensive than the standard Kirschner wire stirrups, but there are no loose parts to get lost. Use these stirrups for exerting traction on the olecranon in fractures of the

humerus, on the metacarpals in fractures of the radius, and on the metatarsals in some fractures of the foot.

• WIRE, Kirschner, plain unthreaded, stainless steel, drill pointed at one end, packet of 5, (a) 0.75x254 mm, four packets only. (b) 1 mm x254 mm, four packets only. (c) 1.5 mm x254

mm, four packets only. These are the standard Kirschner wires. Unfortunately, Kirschner wire is seldom available in district hospitals at the present time. It is one of the purposes of this system of surgery to promote its use.

• INTRODUCER, for Kirschner wire, Pulvertaft's , one only. This will make introducing Kirschner wire much easier.

• CUTTERS, Kirschner wire, one only. If you don't have these,

sterilize a pair of ordinary pliers, but take care to oil them carefully afterwards.

• HAND DRILL, for Kirschner wires and drills, 4 mm capacity cannulated throughout, one only. The chuck of this drill has a

hole through it so that long Kirschner wires can be passed down it and supported close to the skin. If you don't have one of these drills, use a small ordinary carpenter's hand drill and the bits for it and keep them oiled after use. Unfortunately , a carpenter's drill is not cannulated, so you can use it only with drill bits, not with Kirschner wire. The main use of a drill is to exclude osteomyelitis (7.3). If you don't have any kind of drill, you may be able to hammer in a Steinmann pin through cancellous, but not through cortical, bone.

• DRILL BITS, twist, bone, 4 mm, six only. Use these to: (1) Drill a hole for a Steinmann pin. (2) Explore for pus in patients with

osteomyelitis. Don't drill so vigourously that the bit becomes too hot, because the heated bone around the bit may die and form a ring sequestrum.

• FORCEPS, wire cutting, compound lever action with pliers jaws, 170 mm. These can cut and bend Kirschner wire up to 1.6 mm

diameter.

• CORD, braided, for traction, local purchase- If you don't have this use a length of bandage.

• PULLEYS, orthopaedic, assorted, ten only. If you don't have pulleys for Perkins traction, wrap a strip of old X-ray film loosely round

the bar of the bed so it can rotate. Hold it there with adhesive strapping and let the traction cord run over it.

• BARS, for overhead traction. These are needed for ' 90-90' traction (Fig. 77-11), for some pelvic fractures (Fig. 76-2), and for humerus

fractures in unconscious or supine patients (Fig. 71-16). Make them from welded tubing.

• WEIGHTS, for traction, local manufacture. Use bags of sand, or bricks suspended in stockinette, as in Fig. 70-11; each brick weighs

about 3 kg. Or, use lengths of pipe filled with concrete into which a hook has been placed before the concrete sets. For example, 45 cm of 7.5 cm pipe filled with concrete weighs about 7 kg.

70.10 Skin traction

The great advantage of skin traction is that there is no need to pass any instrument through the tissues. But: (1) You cannot apply more than 5 kg, and even then not for long, so it is not suitable for Perkins traction- (2) joints which are crossed by the strapping cannot flex and exercise. (3) The patient's skin may become sensitive to the strapping. (4) Skin traction is poorly tolerated in old patients and easily causes blisters. (5) If it is not carefully managed, the strapping slips off completely. (6) It is very uncomfortable in hot climates. (7) It can occasionally cause ischaemia followed by Volkmann's contracture (78.2)-

Nevertheless, skin traction is particularly useful for treating: (1) elbow fractures in adults and children, (2) fractured femurs in children, (3) fractured femurs in adults where pin traction cannot be used or has caused complications.

SKIN TRACTION

If possible, use special traction strapping. if you use ordinary zinc oxide strapping, help it to stick by applying compound tincture of benzoin (compound tincture of benzoin BPC) to a patient's skin. This is an alcoholic varnish which becomes sticky as it dries. Let it get sticky and then apply the strapping to it.

If necessary, shave the patient's skin. Apply strapping to both sides of his limb, up to but not above the fracture line, or it will fail to exert any traction. Finally, wind a crêpe bandage spirally over it. Never wind circular turns of ahesive strapping round a limb, because the strapping can become too tight.

Either fix a piece of wood in a loop of strapping, as in Fig. 78-3, making it slightly wider than the patient's ankle so that the strapping does not compress his malleoli. Or, fold each end of the strapping, and tie a cord to it.

CAUTION 1 (1) When you apply skin traction to an adult's leg, especially a thin, bony, old one, take great care that the strapping does not press on his common peroneal nerve, as i t winds round the neck of his fibula. This could paralyse it and cause foot drop. (2) Don't let the strapping extend above the fracture line onto the proximal fragment, or it will be useless. (3) Don't let it interfere with his circulation.

If you don't have any crêpe bandage, take some 2 cm zinc oxide tape and wind it in two long right and left spirals round the limb. The spirals should cross each other twice as in Fig. 78-1. This will be safer than applying circular strapping.

DON'T APPLY STRAPPING PROXIMAL TO THE FRACTURE LINE

70.11 Skeletal traction

Fig. 70-13 SITES FOR SKELETAL TRACTION. Pins can spread or introduce infection, so put them through healthy tissue some distance from a fracture, and not through the fracture site itself where injured tissue is easily infected. After de Palma with kind permission.

Steinmann pins are stainless steel rods 2 to 4 mm in diameter. A Denham pin is similar, except that it has a few large threads on it, which you can screw into the cortex of the bone to stop it slipping from side to side. Denham pins are better than Steinmann pins for Perkins traction (78.4) and for calcaneul traction (81.12). But Steinmann pins have other uses, so you will need both- Insert them with the chuck shown in Fig. 70-12. If you don't have a chuck, you can, if necessary, hammer in a Steinmann pin, if you follow the instructions below, but you cannot hammer in a Denham pin, because of its threads. If you wish, you can drill a hole for a pin before you insert it. One difficulty is finding the hole after you have drilled it.

These pins are stiff, so you can apply traction to them without tensioning them. You can use: (1) A Boehler's stirrup (Fig. 70- 12) and a single traction cord and weight. (2) Two Thomas pin mounts (swivels) with two traction cords and two weights. (3) If you don't have either of these, you can put corks on the ends of the pin and tie the cords to them. If you tie the traction cords directly to the ends of a pin, they usually slip off and cause agony as they do so. join the cords together and run them through a pulley attached to a single weight, so as to equalize the pull on either end of the pin as in B, Fig. 70-14.

Pins can spread or introduce infection, so: (1) Put them through healthy tissues some distance from a fracture, and not through a fracture site where the injured tissue is easily infected. You can use them to treat open infected fractures, but the further they are from the site of the infection the better. (2) Keep them still. The pin must stay motionless in the bone, and rotate freely in the stirrup or pin mount. This is why a Denham pin which is firmly screwed into the bone is better than a Steinmann pin. If your pin mounts have set screws, don't tighten them. (3) Never put a pin through a joint capsule. The most serious complication of skeletal traction is infection of the knee joint, or osteomyelitis, particularly in the calcaneus (7.13). If sequestrectomy does not cure this, it may be necessary to remove the whole calcaneus.

A LOOSE PIN PROMOTES INFECTION

STEINMANN'S AND DENHAM'S PINS

EQUIPMENT A sterile sharp pin. A blunt one promotes infection, so sharpen a pin each time, if necessary on a grindstone. A scalpel and local anaesthetic. Some surgeons sterilize the chuck, others use an unsterile chuck and a no-touch technique.

INSERTING THE PIN in most district hospitals this is best done in the theatre. if nursing and ward equipment are very good, you can do it in the ward under local anaesthesia.

If you are going to hammer a pin in, do it through the cancellous bone near the end of a long bone, and not through the thick cortical bone of the shaft, because this may split. Take the patient to the theatre, find two assistants, and give him a general anaesthetic-

If you are using local anaesthesia, sedate him, and apply iodine to the skin where the pin will go in and come out- inject local anaesthetic into the skin, subcutaneous tissue, and periosteum of both sides, making sure it goes under the periosteum-

Make a small nick in the skin with the point of a sharp scalpel. Put the pin in the chuck, and push it through the skin into the bone, twisting it slightly from side to side as you do so. Ask one assistant to hold the patient's leg. Take great care to get the direction of the pin right- Ask your other assistant to check its direction by observing its alignment from the foot of the table. Putting it in is hard work!

Fig. 70-14 TIBIAL TRACTION RIGHT AND WRONG. A, and B, at all sites the pin must be at 90° to the axis of the limb and in a horizonal plane. There must be the same length of pin each side of the limb. If the pin is very skew, one of the cords will slide along it and press into the skin (C, and D). E, if you don't have a Thomas swivel, tie the cord to a cork, not to the pin directly (G). Don't put the pin in too far anteriorly or put it in skew (H)- Kindly contributed by John Stewart.

As the pin comes out of the bone on the other side of the limb, its point will raise the skin, so nick this with a scalpel, and push the pin through it.

When the threads of a Denham pin reach the bone, screw them in about six turns, so that some of them enter its cortex. The threads should lie in the cortex, not in the medulla.

Finally, secure the pin in a Boehler's stirrup or, preferably, with Thomas pin mounts- if the sharp point might injure the patient's other leg, put a cork or a cap on it-

PARTICULAR SITES FOR PIN FIXATION

THE UPPER FEMUR is occasionally used for the central dislocation of the head of a patient's femur (77.4). insert the pin vertically through his greater trochanter.

THE LOWER FEMUR is one of the less satisfactory sites. insert the pin at the level of the flare of the condyles, opposite the upper pole of the patella, slightly anterior to the midline of the leg.

THE UPPER TIBIA is much the most important site, and is used for most fractures of the femur, and many fractures around the knee. if you insert the pin from the lateral side, you are less likely to injure the patient's common peroneal nerve. There are two alternative sites.

If you are using a chuck, put a 4 mm pin through firm cortical bone 3 cm distal to the patient's tibial tuberosity. Go from the lateral to the medial side. Feel the neck of his fibula where his common peroneal nerve will be winding round it, and insert the pin anterior to that point.

If you have no chuck and you have to hammer a pin in, do so from the lateral to the medial side 1 cm distal to the tibial tuberosity through the junction of cortical and cancellous bone, that is, through the flare of the condyles. The pin will be less firmly held here but the bone is less likely to shatter.

CAUTION ! in either site, don't insert the pin too far anteriorly, because there will not be enough bone to hold it.

If his tibia is osteoporotic, apply a short leg cast around it and incorporate the pin in this-

LOWER TIBIA For some fractures of the upper tibia (80.5). insert the pin from the lateral side 4 to 6 cm above the patient's medial malleolus immediately in front of his fibula. This makes sure it is well clear of his ankle joint, and avoids injuring his superficial peroneal nerve. Align it carefully so that it is at right angles to the long axis of his limb and is in the coronal plane-

Fig. 70-16 INSERTING A STEINMANN PIN THROUGH THE CALCANEUS. If you put the pin in too far posteriorly, you will dorsiflex his foot- If you leave it in for more than 15 days you will increase the risk of osteomyelitis. Kindly contributed by Peter Bewes.

CALCANEUS For some fractures of the tibia (Fig. 81-10). insert a 4 mm pin from the lateral side medially through the posterior part of the patient's calcaneus, as in Figs- 70-13 and 70-16. Put the pin in, or just behind, a vertical line joining the tip of his lateral malleolus to the lower border of his heel. if you drive it in at right angles to the axis of his limb, it will emerge well clear of his posterior tibial vessels-

CAUTION ! (1) if you put the pin in too far posteriorly, you will dorsiflex the patient's foot. (2) if you leave it in more than 15 days you will increase the risk of osteomyelitis.

OLECRANON For some fractures of the radius and ulna. Use a thin 2 mm Steinmann pin, and insert it from the medial side laterally, avoiding the patient's ulnar nerve- A Kirschner wire is better, if you have the equipment to apply it.

DRESSINGS Keep the pin track clean. Apply dressings to the entry and exit wounds of the pin and inspect them regularly.

CAUTION ! if there are any signs of infection round a pin at any site, remove it immediately. if you cannot put it back through uninfected skin elsewhere in the bone, change to skin traction.

REMOVING A PIN Use an antiseptic such as iodine to clean the projecting point of the pin that will be drawn through the tissues. Pull it out with the chuck. Don't remove it by hitting the point of the pin with a hammer. Unscrew a Denham pin, and don't merely pull it.

IF A PIN TRACK BECOMES INFECTED, REMOVE THE

70.12 Skeletal traction with Kirschner wires

These are thin flexible stainless steel wires 0-75 to 1 mm in diameter. Use them for. applying traction: (1) Through the heads of the metacarpals in open forearm fractures- (2) Through the olecranon in comminuted fractures of the lower humerus, or when'the patient must lie supine. Kirschner wires are thin and flexible, so you must drill them in, and you can only apply traction to them with an expensive tensioner, such as the Gissane stirrup which will hold them taut. Unlike a Steinmann or Denham pin, where movement takes place between the pin and the pin mount, movement with Kirschner wire traction takes place between the wire and the tissues. This limits the amount of exercise that is practical. Kirschner wires can only be used if they are straight, and because they always bend in use, you cannot use the bent parts again, although you may be able to cut off the straight parts which remain and reuse them.

KIRSCHNER WIRE TRACTION

Sharpen the wire on a stone to a chisel or a triangular point as in Fig. 70-12. Cut it to length with a pair of pliers.

Drill it in with a hand drill (Fig. 70-12)- Use the chuck to hold the wire near the end. In the softer bones of children, you may be able to put it in with pliers.

OLECRANON For some comminuted supracondylar fractures when the patient must lie supine. insert the wire from the medial to the lateral side, taking care to avoid his ulnar nerve.

METACARPALS For open or comminuted fractures of the radius and ulna. insert the wire through the second and third metacarpal from the medial to the lateral side, avoiding the fourth and fifth metacarpals which are more mobile and lie anteriorly. Metacarpal bone is hard, and drilling may be difficult. Don't go too far anteriorly, or you may injure the patient's digital vessels and nerves. Some surgeons claim that metacarpal traction is seldom necessary and prefer skin traction on all the four fingers, while watching the circulation of the fingers with care!

CALCANEUS Kirschner wire traction is an alternative to a Steinmann pin for fractures of the tibia.

DRESSINGS These are the same as for Steinmann pins.

DISTRACTION IS ONE OF THE GREAT ENEMIES OF UNION

70.13 Kirschner wire for bone fixation

Kirschner wire fixation is useful for some severe hand injuries and in some fractures of the olecranon. If you put a short piece of Kirschner wire through two pieces of bone it will keep them aligned, but it is less successful in preventing them coming apart. The easiest way to prevent this happening is to bind the fragments in place with soft stainless steel wire. This is most effectively done by drilling a hole, through the bone, passing the wire through the hole and then looping it in a figure of eight around the bent ends of the pieces of Kirschner wire as in Fig. 72-26. This is Kirschner wire hemicirclage, and is an AO method; it is the most practical way of fixing those fractures of the olecranon (72.18) which must be fixed internally.

INTERNAL FIXATION WITH KIRSCHNER WIRE

INSERTION If you are going to fix a fragment with Kirschner wire alone, use two wires in slightly different planes, avoiding the plane at right angles to the fracture plane.

Use wire cutting forceps to bend over the outer 3 mm of the wires. These bent ends will be easier to find and remove later if necessary; they will not pierce the skin, and they can be used to anchor soft wire for hemicirclage.

Drill the bone and thread soft stainless steel wire thorugh it, as in Figs. 72-26, 79-8, and 75-9a.

CAUTION ! Don't leave Kirschner wire sticking out of the skin, because this increases the chances of infection.

REMOVAL If the wire is causing no trouble, leave it. if the ends of the wire are painful under the skin, or if there is infection, or a sinus, remove it. Feel for the end of the wire under the skin and take it out under local anaesthesia. Make a nick in the skin and remove it with bull nosed pliers filed to a sharp point, or with any convenient instrument- if you cannot find the end of the wire, you may have to give the patient a general anaesthetic and remove it after first applying a tourniquet.