PATHOLOGICAL FRACTURES
Fraktur Fractures may occur even with normal stresses if the bone has been weakened by a change in its structure (e.g. in osteoporosis, osteogenesis imperfecta or Paget’s disease) or through a lytic lesion (e.g. a bone cyst or a metastasis).
TYPES OF FRACTURE
Fractures are variable in appearance but for practical reasons they are divided into a few well-defined groups.
COMPLETE FRACTURES
The bone is split into two or more fragments. The fracture pattern on x-ray can help predict behaviour after reduction: in a transverse fracture the fragments usually remain in place after reduction; if it is oblique or spiral, they tend to shorten and re-displace even if the bone is splinted. In an impacted fracture the fragments are jammed tightly together and the fracture line is indistinct. A comminuted fracture is one in which there are more than two fragments; because there is poor interlocking of the fracture surfaces, these are often unstable.
INCOMPLETE FRACTURES
Here the bone is incompletely divided and the periosteum remains in continuity. In a
greenstick fracture the bone is buckled or bent (like snapping a greentwig); this is seen in children, whose bones are more springy than those of adults. Children can also sustain injuries where the bone is plastically deformed (misshapen) without there being any crack visible on the x-ray. In contrast, compression fractures occur when cancellous bone is crumpled. This happens in adults and typically where this type of bone structure is present, e.g. in the vertebral bodies, calcaneum and tibial plateau.
CLASSIFICATION OF FRACTURES
Sorting fractures into those with similar features brings advantages: it allows any information about a fracture to be applied to others in the group (whether this concerns treatment or prognosis) and it facilitates a common dialogue between surgeons and others
involved in the care of such injuries. Traditional classifications, which often bear the originator’s name, are hampered by being applicable to that type of injury only; even then the term is often inaccurately applied, famously in the case of Pott’s fracture, which is often applied to any fracture around the ankle though that is not what Sir Percival Pott implied when he described the injury in 1765. A universal, anatomically based system facilitates communication and the sharing of data from a variety of countries and populations, thus contributing to advances in research and treatment. An alphanumeric classification developed by Muller and colleagues has now been adapted and revised (Muller et al., 1990; Marsh et al., 2007; Slongo and Audige 2007). Whilst it has yet to be fully validated for reliability and reproducibility,it fulfils the objective of being comprehensive. In this system, the first digit specifies the bone
(1 = humerus, 2 = radius/ulna, 3 = femur, 4 = tibia/fibula) and the second the segment (1 = proximal, 2 = diaphyseal, 3 = distal, 4 = malleolar). A letter specifies the fracture pattern (for the diaphysis: A = simple, B = wedge, C = complex; for the metaphysis: A = extra-articular, B = partial articular, C = complete articular). Two further numbers specify the detailed morphology of the fracture (Fig. 23.3).
HOW FRACTURES ARE DISPLACED
After a complete fracture the fragments usually become displaced, partly by the force of the injury, partly by gravity and partly by the pull of muscles attached to them. Displacement is usually described in terms of translation, alignment, rotation and altered length:
• Translation (shift) – The fragments may be shifted sideways, backward or forward in relation to each other, such that the fracture surfaces lose contact. The fracture will usually unite as long as sufficient contact between surfaces is achieved; this may occur even if reduction is imperfect, or indeed even if the fracture ends are off-ended but the bone segments come to lie side by side.
• Angulation (tilt) – The fragments may be tilted or angulated in relation to each other. Malalignment, if uncorrected, may lead to deformity of the limb.
• Rotation (twist) – One of the fragments may be twisted on its longitudinal axis; the bone looks straight but the limb ends up with a rotational deformity.
• Length – The fragments may be distracted and separated, or they may overlap, due to muscle spasm, causing shortening of the bone.
HOW FRACTURES HEAL
It is commonly supposed that, in order to unite, a fracture must be immobilized. This cannot be so since, with few exceptions, fractures unite whether they are splinted or not; indeed, without a built-in mechanism for bone union, land animals could scarcely have evolved. It is, however, naive to suppose that union would occur if a fracture were kept moving indefinitely; the bone ends must, at some stage, be brought to rest relative to one another. But it is not mandatory for the surgeon to impose this immobility artificially – nature can do it with callus, and callus forms in response to movement, not to splintage. Most fractures are splinted, not to ensure union but to: (1) alleviate pain; (2) ensure that union takes place in good position and (3) permit early movement of the limb and a return of function. The process of fracture repair varies according to the type of bone involved and the amount of movement at the fracture site.
HEALING BY CALLUS
This is the ‘natural’ form of healing in tubular bones; in the absence of rigid fixation, it proceeds in five stages:
1. Tissue destruction and haematoma formation – Vessels are torn and a haematoma forms around and within the fracture. Bone at the fracture surfaces, deprived of a blood supply, dies back for a millimetre or two.
2. Inflammation and cellular proliferation – Within 8 hours of the fracture there is an acute inflammatory reaction with migration of inflammatory cells and the initiation of proliferation and differentiation of mesenchymal stem cells from the periosteum, the breached medullary canal and the surrounding muscle. The fragment ends are surrounded by cellular tissue, which creates a scaffold across the fracture site. A vast array of inflammatory mediators (cytokines and various growth factors) is involved. The clotted haematoma is slowly absorbed and fine new capillaries grow into the area.
3. Callus formation – The differentiating stem cells provide chrondrogenic and osteogenic cell populations; given the right conditions – and this is usually the local biological and biomechanical environment – they will start forming bone and, in some cases, also cartilage. The cell population nowalso includes osteoclasts (probably derived from the new blood vessels), which begin to mop up dead bone. The thick cellular mass, with its islands
of immature bone and cartilage, forms the callus or splint on the periosteal and endosteal surfaces. As the immature fibre bone (or ‘woven’ bone) becomes more densely mineralized, movement at the fracture site decreases progressively and at about 4 weeks after injury the fracture ‘unites’.
4. Consolidation – With continuing osteoclastic and osteoblastic activity the woven bone is transformed into lamellar bone. The system is now rigid enough to allow osteoclasts to burrow through the debris at the fracture line, and close behind them. Osteoblasts fill in the remaining gaps between the fragments with new bone. This is a slow process and it may be several months before the bone is strong enough to carry normal loads.
5. Remodelling – The fracture has been bridged by a cuff of solid bone. Over a period of months, or even years, this crude ‘weld’ is reshaped by a continuous process of alternating bone resorption and formation. Thicker lamellae are laid down where the stresses are high, unwanted buttresses are carved away and the medullary cavity is reformed. Eventually, and especially in children, the bone reassumes something like its normal shape.
HEALING BY DIRECT UNION
Clinical and experimental studies have shown that callus is the response to movement at the fracture site (McKibbin, 1978). It serves to stabilize the fragments as rapidly as possible – a necessary precondition for bridging by bone. If the fracture site is absolutely immobile – for example, an impacted fracture in cancellous bone, or a fracture rigidly immobilized by a metal plate – there is no stimulus for callus (Sarmiento et al., 1980). Instead, osteoblastic new bone formation occurs directly between the fragments. Gaps between the fracture surfaces are invaded by new capillaries and osteoprogenitor cells
growing in from the edges, and new bone is laid down on the exposed surface (gap healing). Where the crevices are very narrow (less than 200 μm), osteogenesis produces lamellar bone; wider gaps are filled first by woven bone, which is then remodelled to lamellar bone. By 3–4 weeks the fracture is solid enough to allow penetration and bridging of the area by bone remodelling units, i.e. osteoclastic ‘cutting cones’ followed by osteoblasts. Where the exposed fracture surfaces are in intimate contact and held rigidly from the outset, internal bridging may occasionally occur without any intermediate stages (contact healing). Healing by callus, though less direct (the term ‘indirect’ could be used) has distinct advantages: it ensures mechanical strength while the bone ends heal,
and with increasing stress the callus grows stronger and stronger (an example of Wolff’s law). With rigid metal fixation, on the other hand, the absence of callus means that there is a long period during which the bone depends entirely upon the metal implant for its integrity. Moreover, the implant diverts stress away from the bone, which may become osteoporotic and not recover fully until the metal is removed.
UNION, CONSOLIDATION AND NON-UNION
Repair of a fracture is a continuous process: any stages into which it is divided are necessarily arbitrary. In this book the terms ‘union’ and ‘consolidation’ are used,
and they are defined as follows:
• Union – Union is incomplete repair; the ensheathing callus is calcified. Clinically the fracture site is still a little tender and, though the bone moves in one piece (and in that sense is united), attempted angulation is painful. X-Rays show the fracture line still clearly visible, with fluffy callus around it. Repair is incomplete and it is not safe to subject the unprotected bone to stress.
• Consolidation – Consolidation is complete repair; the calcified callus is ossified. Clinically the fracture site is not tender, no movement can be obtained and attempted angulation is painless. X-rays show the fracture line to be almost obliterated and crossed by bone trabeculae, with well-defined callus around it. Repair is complete and further protection is unnecessary.
• Timetable – How long does a fracture take to unite and to consolidate? No precise answer is possible because age, constitution, blood supply, type of fracture and other factors all influence the time taken. Approximate prediction is possible and Perkins’ timetable is delightfully simple. A spiral fracture in the upper limb unites in 3 weeks; for consolidation multiply by 2; for the lower limb multiply by 2 again; for transverse fractures multiply again by 2. A more sophisticated formula is as follows. A spiral fracture in the upper limb takes 6–8 weeks to consolidate; the lower limb needs twice as long. Add 25% if the fracture is not spiral or if it involves the femur. Children’s fractures, of course, join more quickly. These figures are only a rough guide; there must be clinical and radiological evidence of consolidation before full stress is permitted without splintage. • Non-union – Sometimes the normal process of fracture repair is thwarted and the bone fails to unite. Causes of non-union are: (1) distraction and separation of the fragments, sometimes the result of interposition of soft tissues between the fragments; (2) excessive movement at the fracture line; (3) a severe injury that renders the local tissues nonviable or nearly so; (4) a poor local blood supply and (5) infection. Of course surgical intervention, if ill-judged, is another cause! Non-unions are septic or aseptic. In the latter group, they can be either stiff or mobile as judged by clinical examination. The mobile ones can be as free and painless as to give the impression of a false joint (pseudoarthrosis). On x-ray, non-unions are typified by a lucent line still present between the bone fragments; sometimes there is exuberant callus trying – but failing – to bridge the gap (hypertrophic non-union) or at times none at all (atrophic non-union) with a sorry, withered appearance to the fracture ends.
CLINICAL FEATURES H
ISTORY
There is usually a history of injury, followed by inability to use the injured limb – but beware! The fracture is not always at the site of the injury: a blow to the knee may fracture the patella, femoral condyles, shaft of the femur or even acetabulum. The patient’s age and mechanism of injury are important. If a fracture occurs with trivial trauma, suspect a pathological lesion. Pain, bruising and swelling are common symptoms
but they do not distinguish a fracture from a soft-tissue injury. Deformity is much more suggestive. Always enquire about symptoms of associated injuries: pain and swelling elsewhere (it is a common mistake to get distracted by the main injury, particularly if it is severe), numbness or loss of movement, skin pallor or cyanosis, blood in the urine, abdominal pain, difficulty with breathing or transient loss of consciousness. Once the acute emergency has been dealt with, ask about previous injuries, or any other musculoskeletal abnormality that might cause confusion when the x-ray is seen. Finally, a general medical history is important, in preparation for anaesthesia or operation.
GENERAL SIGNS
Unless it is obvious from the history that the patient has sustained a localized and fairly modest injury, priority must be given to dealing with the general effects of trauma (see Chapter 22). Follow the ABCs: look for, and if necessary attend to, Airway obstruction, Breathing problems, Circulatory problems and Cervical spine injury. During the secondary survey it will also be necessary to exclude other previously unsuspected injuriesand to be alert to any possible predisposing cause (such as Paget’s disease or a metastasis).
LOCAL SIGNS
Injured tissues must be handled gently. To elicit crepitus or abnormal movement is unnecessarily painful; x-ray diagnosis is more reliable. Nevertheless the familiar headings of clinical examination should always be considered, or damage to arteries, nerves and ligaments may be overlooked. A systematic approach is always helpful:
• Examine the most obviously injured part. • Test for artery and nerve damage.
• Look for associated injuries in the region. • Look for associated injuries in distant parts.
Look
Swelling, bruising and deformity may be obvious, but the important point is whether the skin is intact; if the skin is broken and the wound communicates with the fracture, the injury is ‘open’ (‘compound’). Note also the posture of the distal extremity and the colour of the skin (for tell-tale signs of nerve or vessel damage).
Feel
The injured part is gently palpated for localized tenderness. Some fractures would be missed if not specifically looked for, e.g. the classical sign (indeed the only clinical sign!) of a fractured scaphoid is tenderness on pressure precisely in the anatomical snuff-box. The common and characteristic associated injuries should also be felt for, even if the patient does not complain of them. For example, an isolated fracture of the proximal fibula should always alert to the likelihood of an associated fracture or ligament injury of the ankle, and in high-energy injuries always examine the spine and pelvis. Vascular and peripheral nerve abnormalities should be tested for both before and after treatment.
Move
Crepitus and abnormal movement may be present, but why inflict pain when x-rays are available? It is more important to ask if the patient can move the joints distal to the injury.
X-RAY
X-ray examination is mandatory. Remember the rule of twos:
• Two views – A fracture or a dislocation may not be seen on a single x-ray film, and at least two views (anteroposterior and lateral) must be taken.
• Two joints – In the forearm or leg, one bone may be fractured and angulated. Angulation, however, is impossible unless the other bone is also broken, or a joint dislocated. The joints above and below the fracture must both be included on the x-ray films.
• Two limbs – In children, the appearance of immature epiphyses may confuse the diagnosis of a fracture; x-rays of the uninjured limb are needed for comparison.
• Two injuries – Severe force often causes injuries at more than one level. Thus, with fractures of the calcaneum or femur it is important to also x-ray the pelvis and spine. • Two occasions – Some fractures are notoriously difficult to detect soon after injury, but another x-ray examination a week or two later may show the lesion. Common examples
are undisplaced fractures of the distal end of the clavicle, scaphoid, femoral neck and lateral malleolus, and also stress fractures and physeal injuries wherever they occur.
SPECIAL IMAGING
Sometimes the fracture – or the full extent of the fracture – is not apparent on the plain x-ray. Computed tomography may be helpful in lesions of the spine or for complex joint fractures; indeed, these crosssectional images are essential for accurate visualization of fractures in ‘difficult’ sites such as the calcaneum or acetabulum. Magnetic resonance imaging may be the only way of showing whether a fractured vertebra is threatening to compress the spinal cord. Radioisotope scanning is helpful in diagnosing a suspected stress fracture or other undisplaced fractures.
D
ESCRIPTION
Diagnosing a fracture is not enough; the surgeon should picture it (and describe it) with its properties: (1) Is it open or closed? (2) Which bone is broken, and where? (3) Has it involved a joint surface? (4) What is the shape of the break? (5) Is it stable or unstable? (6) Is it a high-energy or a low-energyinjury? And last but not least (7) who is the person with the injury? In short, the examiner must learn to recognize what has been aptly described as the ‘personality’of the fracture.
Shape of the fracture
A transverse fracture is slow to join because the area of contact is small; if the broken surfaces are accurately apposed, however, the fracture is stable on compression.
A spiral fracture joins more rapidly (because the contact area is large) but is not stable on compression.
Comminuted fractures are often slow to join because: (1) they are associated with more severe softtissue damage and (2) they are likely to be unstable.
Displacement
For every fracture, three components must be assessed:
1. Shift or translation – backwards, forwards, sideways, or longitudinally with impaction or overlap.
2. Tilt or angulation – sideways, backwards or forwards.
3. Twist or rotation – in any direction. A problem often arises in the description of angulation.‘Anterior angulation’ could mean that the apex of the angle points anteriorly or that the distal fragment is tilted anteriorly: in this text it is always the latter meaning that is intended (‘anterior tilt of the distal fragment’ is probably clearer).
SECONDARY INJURIES
Certain fractures are apt to cause secondary injuries and these should always be assumed to have occurred until proved otherwise:
• Thoracic injuries – Fractured ribs or sternum may be associated with injury to the lungs or heart. It is essential to check cardiorespiratory function.
• Spinal cord injury – With any fracture of the spine, neurological examination is essential to: (1) establish whether the spinal cord or nerve roots have been damaged and (2) obtain a baseline for later comparison if neurological signs should change.
• Pelvic and abdominal injuries – Fractures of the pelvis may be associated with visceral injury. It is especially important to enquire about urinary function; if a urethral or bladder injury is suspected, diagnostic urethrograms or cystograms may be necessary.
• Pectoral girdle injuries – Fractures and dislocations around the pectoral girdle may damage the brachial plexus or the large vessels at the base of the neck. Neurological and vascular examination is essential.
TREATMENT OF CLOSED
General treatment is the first consideration: treat the patient, not only the fracture. The principles are discussed in Chapter 22. Treatment of the fracture consists of
manipulation
to improve the position of the fragments, followed by splintage to hold them together until they unite; meanwhile joint movement and function must be preserved. Fracture healing is promoted by physiological loading of the bone, so muscle activity and early
weightbearing are encouraged. These objectives are covered by three simple injunctions: • Reduce.
• Exercise.
Two existential problems have to be overcome. The first is how to hold a fracture adequately and yet permit the patient to use the limb sufficiently; this is a conflict (Hold
versus Move) that the surgeon seeks to resolve as rapidly as possible (e.g. by internal fixation). However the surgeon also wants to avoid unnecessary risks – here is a second conflict (Speed versus Safety). This dual conflict epitomizes the four factors that
dominate fracture management (the term ‘fracture quartet’ seems appropriate). The fact that the fracture is closed (and not open) is no cause for complacency. The most important
factor in determining the natural tendency to heal is the state of the surrounding soft tissues and the local blood supply. Low-energy (or low-velocity) fractures cause only moderate soft-tissue damage; high-energy (velocity) fractures cause severe soft-tissue damage, no matter whether the fracture is open or closed. Tscherne (Oestern and Tscherne, 1984) has devised a helpful classification of closed injuries:
• Grade 0 – a simple fracture with little or no softtissue injury.
• Grade 1 – a fracture with superficial abrasion or bruising of the skin and subcutaneous tissue.
• Grade 2 – a more severe fracture with deep softtissue contusion and swelling.
• Grade 3 – a severe injury with marked soft-tissue damage and a threatened compartment syndrome. The more severe grades of injury are more likely to require some form of mechanical fixation; good skeletal stability aids soft-tissue recovery.
REDUCTION
Although general treatment and resuscitation must always take precedence, there should not be undue delay in attending to the fracture; swelling of the soft parts during the first 12 hours makes reduction increasingly difficult. However, there are some situations in which reduction is unnecessary: (1) when there is little or no displacement; (2) when displacement does not matter initially (e.g. in fractures of the clavicle) and (3) when reduction is unlikely to succeed (e.g. with compression fractures of the vertebrae). Reduction should aim for adequate apposition and normal alignment of the bone fragments. The greater the contact surface area between fragments the more likely healing is to occur. A gap between the fragment ends is a common cause of delayed union or nonunion. On the other hand, so long as there is contact and the fragments are properly aligned, some overlap at the fracture surfaces is permissible. The exception is a fracture involving an articular surface; this should be reduced as near to perfection as possible because any irregularity will cause abnormal load distribution between the surfaces and predispose to degenerative
changes in the articular cartilage. There are two methods of reduction: closed and open.
CLOSED REDUCTION
Under appropriate anaesthesia and muscle relaxation, the fracture is reduced by a three-fold manoeuvre: (1) the distal part of the limb is pulled in the line of the bone; (2) as the fragments disengage, they are repositioned (by reversing the original direction of force if this can be deduced) and (3) alignment is adjusted in each plane. This is most effective when the periosteum and muscles on one side of the fracture remain intact; the soft-tissue strap prevents over-reduction and stabilizes the fracture after it has been reduced (Charnley 1961). Some fractures are difficult to reduce by manipulation because of powerful muscle pull and may need prolonged traction. Skeletal or skin traction for several days allows for soft-tissue tension to decrease and a better alignment to be obtained; this practice is helpful for femoral and tibial shaft fractures and even supracondylar humeral fractures in children. In general, closed reduction is used for all minimally displaced fractures, for most fractures in children and for fractures that are not unstable after reduction and can be held in some form of splint or cast. Unstable fractures can also be reduced using closed methods prior to stabilization with internal or external fixation. This avoids direct manipulation of the fracture site by open reduction, which damages the local blood supply and may lead to slower healing times; increasingly, surgeons resort to reduction manoeuvres that avoid fracture-site exposure, even when the aim is some form of internal or external fixation. Traction, which reduces fracture fragments through ligamentotaxis (ligament pull), can usually be applied by using a fracture table or bone distractor.
OPEN REDUCTION
Operative reduction of the fracture under direct vision is indicated: (1) when closed reduction fails, either because of difficulty in controlling the fragments or because soft tissues are interposed between them; (2) when there is a large articular fragment that needs accurate positioning or (3) for traction (avulsion) fractures in which the fragments are held apart. As a rule, however, open reduction is merely the first step to internal fixation.
HOLD REDUCTION
The word ‘immobilization’ has been deliberately avoided because the objective is seldom complete immobility; usually it is the prevention of displacement. Nevertheless, some restriction of movement is needed to promote soft-tissue healing and to allow free movement of the unaffected parts. The available methods of holding reduction are: • Continuous traction.
• Cast splintage. • Functional bracing. • Internal fixation. • External fixation.
In the modern technological age, ‘closed’ methods are often scorned – an attitude arising from ignorance rather than experience. The muscles surrounding a fracture, if they are intact, act as a fluid compartment; traction or compression creates a hydraulic effect that is capable of splinting the fracture. Therefore closed methods are most suitable for fractures with intact soft tissues, and are liable to fail if they are used as the primary method of treatment for fractures with severe soft-tissue damage. Other contraindications to nonoperative methods are inherently unstable fractures, multiple fractures and fractures in confused or uncooperative patients. If these constraints are borne in mind, closed reduction can be sensibly considered in choosing the most suitable method of fracture splintage. Remember, too, that the objective is to splint the fracture, not the entire limb!
CONTINUOUS TRACTION
Traction is applied to the limb distal to the fracture, so as to exert a continuous pull in the long axis of the bone, with a counterforce in the opposite direction (to prevent the patient being merely dragged along the bed). This is particularly useful for shaft fractures that are oblique or spiral and easily displaced by muscle contraction. Traction cannot
hold a fracture still; it can pull along bone straight and hold it out to length but to maintain accurate reduction is sometimes difficult.
Meanwhile the patient can move the joints and exercise the muscles.
Traction is safe enough, provided it is not excessive and care is taken when inserting the traction pin. The problem is speed: not because the fracture unites slowly (it does not) but because lower limb traction keeps the patient in hospital. Consequently, as soon as the fracture is ‘sticky’ (deformable but not displaceable), traction should be replaced by bracing, if this
method is feasible. Traction includes:
• Traction by gravity – This applies only to upper limb injuries. Thus, with a wrist sling the weight of the arm provides continuous traction to the
humerus. For comfort and stability, especially with a transverse fracture, a U-slab of plaster may be bandaged on or, better, a removable plastic sleeve from the axilla to just above the elbow is held on with Velcro.
• Skin traction – Skin traction will sustain a pull of no more than 4 or 5 kg. Holland strapping or oneway-stretch Elastoplast is stuck to the shaved skin
and held on with a bandage. The malleoli are protected by Gamgee tissue, and cords or tapes are
used for traction.
• Skeletal traction – A stiff wire or pin is inserted – usually behind the tibial tubercle for hip, thigh and knee injuries, or through the calcaneum for tibial fractures – and cords tied to them for applying traction. Whether by skin or skeletal traction, the fracture
is reduced and held in one of three ways: fixed traction, balanced traction or a combination of the two.
Fixed traction
The pull is exerted against a fixed point. The usual method is to tie the traction cords to the distal end of a Thomas’ splint and pull the leg down until the proximal, padded ring of the splint abuts firmly against the
pelvis.
Balanced traction
Here the traction cords are guided over pulleys at the foot of the bed and loaded with weights; counter-traction is provided by the weight of the body when the
foot of the bed is raised.
Combined traction
If a Thomas’ splint is used, the tapes are tied to the end of the splint and the entire splint is then suspended, as in balanced traction.
Complications of traction
Circulatory embarrassment In children especially,
traction tapes and circular bandages may constrict the circulation; for this reason ‘gallows traction’, in which the baby’s legs are suspended from an overhead beam, should never be used for children over 12 kg in weight.
Nerve injury In older people, leg traction may
predispose to peroneal nerve injury and cause a dropfoot; the limb should be checked repeatedly to see that
it does not roll into external rotation during traction.
Pin site infection Pin sites must be kept clean and should be checked daily.
CAST SPLINTAGE
Plaster of Paris is still widely used as a splint, especially for distal limb fractures and for most children’s fractures. It is safe enough, so long as the practitioner is
alert to the danger of a tight cast and provided pressure sores are prevented. The speed of union is neither greater nor less than with traction, but the patient can go home sooner. Holding reduction is usually no problem and patients with tibial fractures can bear weight on the cast. However, joints encased in plaster cannot move and are liable to stiffen; stiffness, which has earned the sobriquet ‘fracture disease’, is the problem with conventional casts. While the swelling and haematoma resolve, adhesions may form that bind muscle fibres to each other and to the bone; with articular fractures, plaster perpetuates surface irregularities (closed reduction is seldom perfect) and lack of
movement inhibits the healing of cartilage defects. Newer substitutes have some advantages over plaster (they are impervious to water, and also lighter) but as long as they are used as full casts the basic drawback
is the same.
Stiffness can be minimized by: (1) delayed splintage – that is, by using traction until movement has been
regained, and only then applying plaster; or (2) weeks, when the limb can be handled without too
much discomfort, replacing the cast by a functional brace which permits joint movement.
Technique
After the fracture has been reduced, stockinette is
threaded over the limb and the bony points are protected with wool. Plaster is then applied. While it is
setting the surgeon moulds it away from bony prominences; with shaft fractures three-point pressure can
be applied to keep the intact periosteal hinge under tension and thereby maintain reduction.
If the fracture is recent, further swelling is likely; the plaster and stockinette are therefore split from top to bottom, exposing the skin. Check x-rays are essential and the plaster can be wedged if further correction of angulation is necessary.
With fractures of the shafts of long bones, rotation is controlled only if the plaster includes the joints above and below the fracture. In the lower limb, the knee is usually held slightly flexed, the ankle at a right angle and the tarsus and forefoot neutral (this ‘plantigrade’ position is essential for normal walking). In the
upper limb the position of the splinted joints varies with the fracture. Splintage must not be discontinued (though a functional brace may be substituted) until the fracture is consolidated; if plaster changes are needed, check x-rays are essential.
Complications
Plaster immobilization is safe, but only if care is taken to prevent certain complications. These are tight cast, pressure sores and abrasion or laceration of the skin.
Tight cast The cast may be put on too tightly, or it may become tight if the limb swells. The patient complains of diffuse pain; only later – sometimes much later – do the signs of vascular compression appear. The limb should be elevated, but if the pain persists, the only safe course is to split the cast and ease it open: (1)
throughout its length and (2) through all the padding down to skin. Whenever swelling is anticipated the cast
should be applied over thick padding and the plastershould be split before it sets, so as to provide a firm
but not absolutely rigid splint.
Pressure sores Even a well-fitting cast may press upon the skin over a bony prominence (the patella, heel, elbow or head of the ulna). The patient complains of localized pain precisely over the pressure spot. Such localized pain demands immediate inspection through a window in the cast.
Skin abrasion or laceration This is really a complication of removing plasters, especially if an electric saw is used. Complaints of nipping or pinching during plaster removal should never be ignored; a ripped forearm is a good reason for litigation.
Loose cast Once the swelling has subsided, the cast may no longer hold the fracture securely. If it is loose,
the cast should be replaced.
F
UNCTIONAL BRACING
Functional bracing, using either plaster of Paris or one of the lighter thermoplastic materials, is one way of preventing joint stiffness while still permitting fracture splintage and loading. Segments of a cast are applied only over the shafts of the bones, leaving the joints free; the cast segments are connected by metal or plastic hinges that allow movement in one plane. The
splints are ‘functional’ in that joint movements are much less restricted than with conventional casts. Functional bracing is used most widely for fractures of the femur or tibia, but since the brace is not very rigid, it is usually applied only when the fracture is beginning to unite, i.e. after 3–6 weeks of traction or conventional plaster. Used in this way, it comes out well on all four of the basic requirements: the fracture can be held reasonably well; the joints can be moved; the fracture joins at normal speed (or perhaps slightly quicker) without keeping the patient in hospital and the method is safe.
Technique
Considerable skill is needed to apply an effective brace. First the fracture is ‘stabilized’: by a few days on traction or in a conventional plaster for tibial fractures; and by a few weeks on traction for femoral fractures (until the fracture is sticky, i.e. deformable but not displaceable). Then a hinged cast or splint is applied, which holds the fracture snugly but permits
joint movement; functional activity, including weightbearing, is encouraged. Unlike internal fixation, functional
bracing holds the fracture through compression
of the soft tissues; the small amount of movement that occurs at the fracture site through using the limb encourages vascular proliferation and callus formation. Details of the rationale, technique and applications are given by Sarmiento and Latta (Sarmiento and Latta 1999, 2006).
INTERNAL FIXATION
Bone fragments may be fixed with screws, a metal plate held by screws, a long intramedullary rod or nail (with or without locking screws), circumferential bands or a combination of these methods.
Properly applied, internal fixation holds a fracture securely so that movement can begin at once; with
early movement the ‘fracture disease’ (stiffness andthe patient can leave hospital as soon as the wound
is healed, but he must remember that, even though the bone moves in one piece, the fracture is not united – it is merely held by a metal bridge and unprotected weightbearing is, for some time, unsafe.
The greatest danger, however, is sepsis; if infection
supervenes, all the manifest advantages of internal fixation (precise reduction, immediate stability and early
movement) may be lost. The risk of infection depends upon: (1) the patient – devitalized tissues, a dirty wound and an unfit patient are all dangerous; (2) the
surgeon – thorough training, a high degree of surgical dexterity and adequate assistance are all essential and (3) the facilities – a guaranteed aseptic routine, a full range of implants and staff familiar with their use are all indispensable.
Indications
Internal fixation is often the most desirable form of treatment. The chief indications are:
1. Fractures that cannot be reduced except by operation.
2. Fractures that are inherently unstable and prone to re-displace after reduction (e.g. mid-shaft fractures of the forearm and some displaced ankle
fractures). Also included are those fractures liable to be pulled apart by muscle action (e.g. transverse fracture of the patella or olecranon).
3. Fractures that unite poorly and slowly, principally fractures of the femoral neck.
4. Pathological fractures in which bone disease may prevent healing.
5. Multiple fractures where early fixation (by either internal or external fixation) reduces the risk of general complications and late multisystem organ failure (Pape et al., 2005; Roberts et al., 2005). 6. Fractures in patients who present nursing difficulties (paraplegics, those with multiple injuries and the very elderly).
Types of internal fixation
Interfragmentary screws Screws that are only partially threaded (a similar effect is achieved by overdrilling the ‘near’ cortex of bone) exert a compression or ‘lag’
effect when inserted across two fragments. The technique is useful for reducing single fragments onto
the main shaft of a tubular bone or fitting together fragments of a metaphyseal fracture.
Wires (transfixing, cerclage and tension-band) Transfixing wires, often passed percutaneously, can hold major fracture fragments together. They are used in situations where fracture healing is predictably quick (e.g. in children or for distal radius fractures), and some form of external splintage (usually a cast) is applied as supplementary support.
Cerclage and tension-band wires are essentially loops of wire passed around two bone fragments and then tightened to compress the fragments together. When using cerclage wires, make sure that the wires hug the bone and do not embrace any of the closelying nerves or vessels.
Both techniques are used for patellar fractures: the tension-band wire is placed such that the maximum compressive force is over the tensile surface, which is usually the convex side of the bone.
Plates and screws This form of fixation is useful for treating metaphyseal fractures of long bones and diaphyseal fractures of the radius and ulna. Plates have five different functions:
1. Neutralization – when used to bridge a fracture and supplement the effect of interfragmentary lag screws; the plate is to
resist torque and shortening.
2. Compression – often used in metaphyseal fractures where healing across the cancellous fracture gap may occur directly, without periosteal callus. This technique is less
appropriate for diaphyseal fractures and there has been a move towards the use of long plates that span the fracture, thus achieving some stability without totally sacrificing the biological (and callus producing) effect of movement.
3. Buttressing – here the plate props up the ‘overhang’ of the expanded metaphyses of long bones (e.g. in treating fractures of the proximal tibial plateau).
4. Tension-band – using a plate in this manner, again on the tensile surface of the bone, allows compression to be applied to the biomechanically more advantageous side of the fracture.
5. Anti-glide – by fixing a plate over the tip of a spiral or oblique fracture line and then using
the plate as a reduction aid, the anatomy is restored with minimal stripping of soft tissues.
The position of the plate acts to prevent shortening and recurrent displacement of the fragments.
Intramedullary nails These are suitable for long bones. A nail (or long rod) is inserted into the medullary canal to splint the fracture; rotational forces are resisted by introducing transverse interlocking screws that transfix the bone cortices and the nail proximal and distal to the fracture. Nails are used with or without prior reaming of the medullary canal; reamed nails achieve an interference fit in addition to the added stability from interlocking screws, but at the expense of temporary loss of the intramedullary blood supply.
Complications of internal fixation
Most of the complications of internal fixation are due to poor technique, poor equipment or poor operating conditions:
Infection Iatrogenic infection is now the most common cause of chronic osteomyelitis; the metal does
not predispose to infection but the operation and quality of the patient’s tissues do.
Non-union If the bones have been fixed rigidly with a gap between the ends, the fracture may fail to unite. This is more likely in the leg or the forearm if one bone is fractured and the other remains intact. Other causes of non-union are stripping of the soft tissues
and damage to the blood supply in the course of operative fixation.
Implant failure Metal is subject to fatigue and can fail unless some union of the fracture has occurred. Stress must therefore be avoided and a patient with a broken tibia internally fixed should walk with crutches and stay away from partial weightbearing for 6 weeks or longer, until callus or other radiological sign of fracture healing is seen on x-ray. Pain at the fracture site is a danger signal and must be investigated.
Refracture It is important not to remove metal
implants too soon, or the bone may refracture. A year is the minimum and 18 or 24 months safer; for several
weeks after removal the bone is weak, and care or protection is needed.
EXTERNAL FIXATION
A fracture may be held by transfixing screws or tensioned wires that pass through the bone above and below the fracture and are attached to an external frame. This is especially applicable to the tibia and pelvis, but the method is also used for fractures of the femur, humerus, lower radius and even bones of the hand.
Indications
External fixation is particularly useful for:
1. Fractures associated with severe soft-tissue damage (including open fractures) or those that are
contaminated, where internal fixation is risky and repeated access is needed for wound inspection, dressing or plastic surgery.
2. Fractures around joints that are potentially suitable for internal fixation but the soft tissues are too
swollen to allow safe surgery; here, a spanning external fixator provides stability until soft-tissue conditions improve.
3. Patients with severe multiple injuries, especially if there are bilateral femoral fractures, pelvic
fractures with severe bleeding, and those with limb and associated chest or head injuries.
4. Ununited fractures, which can be excised and compressed; sometimes this is combined with bone lengthening to replace the excised segment. 5. Infected fractures, for which internal fixation might not be suitable.
Technique
The principle of external fixation is simple: the bone is transfixed above and below the fracture with screws or tensioned wires and these are then connected to each other by rigid bars. There are numerous types of external fixation devices; they vary in the technique of application and each type can be constructed to provide varying degrees of rigidity and stability. Most of
them permit adjustment of length and alignment after application on the limb.
The fractured bone can be thought of as broken into segments – a simple fracture has two segments whereas a two-level (segmental) fracture has three and so on. Each segment should be held securely, ideally with the half-pins or tensioned wires straddling the length of that segment. The wires and half-pins must be inserted with care. Knowledge of ‘safe corridors’ is essential so as to avoid injuring nerves or vessels; in addition, the entry sites should be irrigated to prevent burning of the bone (a temperature of only 50oC can cause bone death). The fracture is then reduced by connecting the various groups of pins and wires by rods.
Depending on the stability of fixation and the
underlying fracture pattern, weightbearing is started as early as possible to ‘stimulate’ fracture healing.
Some fixators incorporate a telescopic unit that allows ‘dynamization’; this will convert the forces of weightbearing into axial micromovement at the fracture site,
thus promoting callus formation and accelerating bone union (Kenwright et al., 1991).
Complications
Damage to soft-tissue structures Transfixing pins or wires may injure nerves or vessels, or may tether ligaments and inhibit joint movement. The surgeon must be thoroughly familiar with the cross-sectional anatomy before operating.
Overdistraction If there is no contact between the fragments, union is unlikely.
Pin-track infection This is less likely with good
operative technique. Nevertheless, meticulous pin-site care is essential, and antibiotics should be administered immediately if infection occurs.
EXERCISE
More correctly, restore function – not only to the injured parts but also to the patient as a whole. The
objectives are to reduce oedema, preserve joint movement, restore muscle power and guide the patient
back to normal activity: Prevention of oedema Swelling is almost inevitable after a fracture and may cause skin stretching and blisters.
Persistent oedema is an important cause of joint
stiffness, especially in the hand; it should be prevented if possible, and treated energetically if it is already present, by a combination of elevation and exercise. Not every patient needs admission to hospital, and less severe injuries of the upper limb are successfully managed by placing the arm in a sling; but it is then essential to insist on active use, with movement of all the joints that are free. As with most closed fractures, in all open fractures and all fractures treated by internal fixation it must be assumed that swelling will occur; the limb should be elevated and active exercise begun as soon as the patient will tolerate this. The essence of soft-tissue care may be summed up thus: elevate and exercise; never dangle, never force.
Elevation An injured limb usually needs to be elevated; after reduction of a leg fracture the foot of the bed is raised and exercises are begun. If the leg is in plaster the limb must, at first, be dependent for only short periods; between these periods, the leg is elevated on a chair. The patient is allowed, and encouraged, to exercise the limb actively, but not to let it dangle. When the plaster is finally removed, a similar routine of activity punctuated by elevation is practised until circulatory control is fully restored.
Injuries of the upper limb also need elevation. A
sling must not be a permanent passive arm-holder; the limb must be elevated intermittently or, if need be, continuously.
Active exercise Active movement helps to pump away
oedema fluid, stimulates the circulation, prevents softtissue adhesion and promotes fracture healing. A limb
encased in plaster is still capable of static muscle contraction and the patient should be taught how to
do this. When splintage is removed the joints are mobilized and muscle-building exercises are steadily increased. Remember that the unaffected joints need exercising too; it is all too easy to neglect a stiffening shoulder while caring for an injured wrist or hand.
Assisted movement It has long been taught that passive movement can be deleterious, especially with injuries around the elbow, where there is a high risk of
developing myositis ossificans. Certainly forced movements should never be permitted, but gentle assistance during active exercises may help to retain function or regain movement after fractures involving the articular surfaces. Nowadays this is done with machines that can be set to provide a specified range and rate of movement (‘continuous passive motion’).
Functional activity As the patient’s mobility improves, an increasing amount of directed activity is included in the programme. He may need to be taught again how to perform everyday tasks such as walking, getting in and out of bed, bathing, dressing or handling eating utensils. Experience is the best teacher and the patient is encouraged to use the injured limb as much as possible. Those with very severe or extensive injuries may benefit from spending time in a special
rehabilitation unit, but the best incentive to full recovery is the promise of re-entry into family life, recreational pursuits and meaningful work.
TREATMENT OF OPEN
FRACTURES
INITIAL MANAGEMENT
Patients with open fractures may have multiple injuries;
a rapid general assessment is the first step and any lifethreatening conditions are addressed (see Chapter 22).
The open fracture may draw attention away from other more important conditions and it is essential that the step-by-step approach in advanced trauma life support not be forgotten.
When the fracture is ready to be dealt with, the
wound is first carefully inspected; any gross contamination is removed, the wound is photographed with a
Polaroid or digital camera to record the injury and the area then covered with a saline-soaked dressing under an impervious seal to prevent desiccation. This is left undisturbed until the patient is in the operating theatre. The patient is given antibiotics, usually co-amoxiclav or cefuroxime, but clindamycin if the patient is
allergic to penicillin. Tetanus prophylaxis is administered: toxoid for those previously immunized, human
antiserum if not. The limb is then splinted until surgery is undertaken.
The limb circulation and distal neurological status will need checking repeatedly, particularly after any fracture reduction manoeuvres. Compartment syndrome is not prevented by there being an open fracture;
vigilance for this complication is wise.
CLASSIFYING THE INJURY
nature of the soft-tissue injury (including the wound
size) and the degree of contamination. Gustilo’s classification of open fractures is widely used (Gustilo et
al., 1984):
Type 1 – The wound is usually a small, clean puncture through which a bone spike has protruded. There is little soft-tissue damage with no crushing and the fracture is not comminuted (i.e. a low-energy fracture).
Type II – The wound is more than 1 cm long, but there is no skin flap. There is not much soft-tissue damage and no more than moderate crushing or comminution of the fracture (also a low- to moderate-energy fracture).
Type III – There is a large laceration, extensive
damage to skin and underlying soft tissue and, in the most severe examples, vascular compromise. The injury is caused by high-energy transfer to the bone and soft tissues. Contamination can be significant. There are three grades of severity. In type III A the fractured bone can be adequately covered by soft tissue despite the laceration. In type III B there is extensive periosteal stripping and fracture cover is not
possible without use of local or distant flaps. The fracture is classified as type III C if there is an arterial
injury that needs to be repaired, regardless of the amount of other soft-tissue damage.
The incidence of wound infection correlates
directly with the extent of soft-tissue damage, rising from less than 2 per cent in type I to more than 10 per cent in type III fractures.
PRINCIPLES OF TREATMENT
All open fractures, no matter how trivial they may seem, must be assumed to be contaminated; it is important to try to prevent them from becoming infected. The four essentials are:
• Antibiotic prophylaxis.
• Urgent wound and fracture debridement. • Stabilization of the fracture.
• Early definitive wound cover.
Sterility and antibiotic cover
The wound should be kept covered until the patient
reaches the operating theatre. In most cases co-amoxiclav or cefuroxime (or clindamycin if penicillin allergy
is an issue) is given as soon as possible, often in the Accident and Emergency department. At the time of debridement, gentamicin is added to a second dose of the first antibiotic. Both antibiotics provide prophylaxis against the majority of Gram-positive and Gramnegative bacteria that may have entered the wound at
the time of injury. Only co-amoxiclav or cefuroxime (or clindamycin) is continued thereafter; as wounds of Gustilo grade I fractures can be closed at the time of debridement, antibiotic prophylaxis need not be for more than 24 hours. With Gustilo grade II and IIIA fractures, some surgeons prefer to delay closure after a ‘second look’ procedure. Delayed cover is also usually practised in most cases of Grade IIIB and IIIC
injuries. As the wounds have now been present in a hospital environment for some time, and there are data to indicate infections after such open fractures are caused mostly by hospital-acquired bacteria and
not seeded at the time of injury, gentamicin and vancomycin (or teicoplanin) are given at the time of
definitive wound cover. These antibiotics are effective against methicillin-resistant Staphylococcus aureus and Pseudomonas, both of which are near the top of the league table of responsible bacteria. The total period of antibiotic use for these fractures should not be greater than 72 hours (Table 23.1).
Debridement
The operation aims to render the wound free of foreign material and of dead tissue, leaving a clean surgical field and tissues with a good blood supply
throughout. Under general anaesthesia the patient’s clothing is removed, while an assistant maintains traction on the injured limb and holds it still. The dressing
previously applied to the wound is replaced by a sterile pad and the surrounding skin is cleaned. The
pad is then taken off and the wound is irrigated thoroughly with copious amounts of physiological saline.
The wound is covered again and the patient’s limb then prepped and draped for surgery.
Many surgeons prefer to use a tourniquet as this provides a bloodless field. However this induces
ischaemia in an already badly injured leg and can make it difficult to recognize which structures are devitalized. A compromise is to apply the tourniquet but not
to inflate it during the debridement unless absolutely necessary.
Because open fractures are often high-energy injuries with severe tissue damage, the operation should be performed by someone skilled in dealing with both skeletal and soft tissues; ideally this will be a joint effort by orthopaedic and plastic surgeons. The following principles must be observed:
Wound excision The wound margins are excised, but only enough to leave healthy skin edges.
Wound extension Thorough cleansing necessitates adequate exposure; poking around in a small wound to remove debris can be dangerous. If extensions are needed they should not jeopardize the creation of skin flaps for wound cover if this should be needed. The safest extensions are to follow the line of fasciotomy incisions; these avoid damaging important perforator vessels that can be used to raise skin flaps for eventual fracture cover.
Delivery of the fracture Examination of the fracture surfaces cannot be adequately performed without extracting the bone from within the wound. The simplest (and gentlest) method is to bend the limb in the manner in which it was forced at the moment of injury; the fracture surfaces will be exposed through the wound without any additional damage to the soft tissues. Large bone levers and retractors should not be used.
a nutrient medium for bacteria. Dead muscle can be recognized by its purplish colour, its mushy
consistency, its failure to contract when stimulated and its failure to bleed when cut. All doubtfully viable tissue, whether soft or bony, should be removed. The fracture ends can be nibbled away until seen to bleed.
Wound cleansing All foreign material and tissue debris is removed by excision or through a wash with copious quantities of saline. A common mistake is to inject syringefuls of fluid through a small aperture – this only serves to push contaminants further in; 6–12 L of saline may be needed to irrigate and clean an open fracture of a long bone. Adding antibiotics or
antiseptics to the solution has no added benefit.
Nerves and tendons As a general rule it is best to leave cut nerves and tendons alone, though if the wound is
absolutely clean and no dissection is required – and provided the necessary expertise is available – they can be
sutured.
Wound closure
A small, uncontaminated wound in a Grade I or II fracture may (after debridement) be sutured, provided this can be done without tension. In the more severe grades of injury, immediate fracture stabilization and wound cover using split-skin grafts, local or distant flaps is ideal, provided both orthopaedic and plastic surgeons are satisfied that a clean, viable wound has been achieved after debridement. In the absence of this combined approach at the time of debridement, the fracture is stabilized and the wound left open and dressed with an impervious dressing. Adding gentamicin beads under the dressing has been shown to help, as has the use of vacuum dressings. Return to surgery for a ‘second look’ should have definitive fracture cover as an objective. It should be done by 48–
72 hours, and not later than 5 days. Open fractures do not fare well if left exposed for long and multiple debridement can be self-defeating.
Stabilizing the fracture
Stabilizing the fracture is important in reducing the likelihood of infection and assisting recovery of the soft tissues. The method of fixation depends on the degree of contamination, length of time from injury to operation and amount of soft-tissue damage. If there is no obvious contamination and definitive
wound cover can be achieved at the time of debridement, open fractures of all grades can be treated as for
a closed injury; internal or external fixation may be appropriate depending on the individual characteristics of the fracture and wound. This ideal scenario of
judicious soft-tissue and bone debridement, wound cleansing, immediate stabilization and cover is only possible if orthopaedic and plastic surgeons are present at the time of initial surgery.
If wound cover is delayed, then external fixation is safer; however, the surgeon must take care to insert the fixator pins away from potential flaps needed by the plastic surgeon!
The external fixator may be exchanged for internalfixation at the time of definitive wound cover as long
as (1) the delay to wound cover is less than 7 days; (2) wound contamination is not visible and (3) internal fixation can control the fracture as well as the external fixator. This approach is less risky than introducing internal fixation at the time of initial surgery and leaving both metalwork and bone exposed until definitive
cover several days later.
Aftercare
In the ward, the limb is elevated and its circulation carefully watched. Antibiotic cover is continued but only for a maximum of 72 hours in the more severe grades of injury. Wound cultures are seldom helpful as osteomyelitis, if it were to ensue, is often caused by hospital-derived organisms; this emphasizes the need for good debridement and early fracture cover.
SEQUELS TO OPEN FRACTURES
Skin
If split-thickness skin grafts are used inappropriately, particularly where flap cover is more suited, there can be areas of contracture or friable skin that breaks
down intermittently. Reparative or reconstructive surgery by a plastic surgeon is desirable.
Bone
Infection involves the bone and any implants that may have been used. Early infection may present as wound inflammation without discharge. Identifying the
causal organism without tissue samples is difficult but, at best guess, it is likely to be S. aureus (including
methicillin-resistant varieties) or Pseudomonas. Suppression by appropriate antibiotics, as long as the fixation
remains stable, may allow the fracture to
proceed to union, but further surgery is likely later, when the antibiotics are stopped.
Late presentation may be with a sinus and x-ray evidence of sequestra. The implants and all avascular
pieces of bone should be removed; robust soft tissue cover (ideally a flap) is needed. An external fixator can be used to bridge the fracture. If the resulting defect is too large for bone grafting at a later stage, the patient should be referred to a centre with the necessary experience and facilities for limb reconstruction.
Joints
When an infected fracture communicates with a joint, the principles of treatment are the same as with bone infection, namely debridement and drainage, drugs and splintage. On resolution of the infection, attention can be given to stabilizing the fracture so that joint
movement can recommence. Permanent stiffness is a real threat; where fracture stabilization cannot be achieved to allow movement, the joint should be splinted in the optimum position for ankylosis, lest this should occur.
COMPLICATIONS OF
FRACTURES
shock, fat embolism, cardiorespiratory failure etc.) are dealt with in Chapter 22.
Local complications can be divided into early (those that arise during the first few weeks following injury) and late.
EARLY COMPLICATIONS
Early complications may present as part of the primary injury or may appear only after a few days or weeks.
VISCERAL INJURY
Fractures around the trunk are often complicated by injuries to underlying viscera, the most important being penetration of the lung with life-threatening pneumothorax following rib fractures and rupture of the bladder or urethra in pelvic fractures. These injuries require emergency treatment.
VASCULAR INJURY
The fractures most often associated with damage to a major artery are those around the knee and elbow, and those of the humeral and femoral shafts. The artery may be cut, torn, compressed or contused, either by the initial injury or subsequently by jagged bone fragments. Even if its outward appearance is normal, the intima may be detached and the vessel blocked by thrombus, or a segment of artery may be in spasm. The effects vary from transient diminution of blood flow to profound ischaemia, tissue death and peripheral gangrene.
Clinical features
The patient may complain of paraesthesia or numbness in the toes or the fingers. The injured limb is cold
and pale, or slightly cyanosed, and the pulse is weak or absent. X-rays will probably show one of the ‘highrisk’ fractures listed above. If a vascular injury is suspected an angiogram should be performed
immediately; if it is positive, emergency treatment must be started without further delay.
Treatment
All bandages and splints should be removed. The fracture is re-x-rayed and, if the position of the bones suggests that the artery is being compressed or kinked,
prompt reduction is necessary. The circulation is then reassessed repeatedly over the next half hour. If there is no
improvement, the vessels must be explored by operation – preferably with the benefit of preoperative or peroperative angiography. A cut vessel can be sutured, or a segment may be replaced by a vein graft; if it is thrombosed,
endarterectomy may restore the blood flow. If vessel repair is undertaken, stable fixation is a must and where it
is practicable, the fracture should be fixed internally.
N
ERVE INJURY
Nerve injury is particularly common with fractures of
the humerus or injuries around the elbow or the knee(see also Chapter 11). The telltale signs should be
looked for (and documented) during the initial examination and again after reduction of the fracture.
In closed injuries the nerve is seldom severed, and spontaneous recovery should be awaited – it occurs in 90 per cent within 4 months. If recovery has not
occurred by the expected time, and if nerve conduction studies and EMG fail to show evidence of recovery, the nerve should be explored.
Open nerve injuries
With open fractures the nerve injury is more likely to be complete. In these cases the nerve should be explored at the time of debridement and repaired at the time or at wound closure.
Acute nerve compression
Nerve compression, as distinct from a direct injury, sometimes occurs with fractures or dislocations
around the wrist. Complaints of numbness or paraesthesia in the distribution of the median or ulnar
nerves should be taken seriously and the patient monitored closely; if there is no improvement within 48
hours of fracture reduction or splitting of bandages around the splint, the nerve should be explored and decompressed.
COMPARTMENT SYNDROME
Fractures of the arm or leg can give rise to severe ischaemia, even if there is no damage to a major vessel. Bleeding, oedema or inflammation (infection)
may increase the pressure within one of the osseofascial compartments; there is reduced capillary flow,
which results in muscle ischaemia, further oedema, still greater pressure and yet more profound ischaemia – a vicious circle that ends, after 12 hours or less, in necrosis of nerve and muscle within the compartment. Nerve is capable of regeneration but muscle, once infarcted, can never recover and is replaced by inelastic fibrous tissue (Volkmann’s ischaemic contracture). A similar cascade of events may be caused by swelling of a limb inside a tight plaster cast.
Clinical features
High-risk injuries are fractures of the elbow, forearm
bones, proximal third of the tibia, and also multiple fractures of the hand or foot, crush injuries and circumferential
burns. Other precipitating factors are
operation (usually for internal fixation) or infection. The classic features of ischaemia are the five Ps: • Pain
• Paraesthesia • Pallor
• Paralysis • Pulselessness.
However in compartment syndrome the ischaemia occurs at the capillary level, so pulses may still be felt and the skin may not be pale! The earliest of the ‘classic’ features are pain (or a ‘bursting’ sensation),
altered sensibility and paresis (or, more usually, weakness in active muscle contraction). Skin sensation
should be carefully and repeatedly checked. Ischaemic muscle is highly sensitive to stretch. If
the limb is unduly painful, swollen or tense, the muscles (which may be tender) should be tested by stretching
them. When the toes or fingers are passively hyperextended, there is increased pain in the calf or forearm.
Confirmation of the diagnosis can be made by measuring the intracompartmental pressures. So important
is the need for early diagnosis that some surgeons advocate the use of continuous compartment pressure
monitoring for high-risk injuries (e.g. fractures of the tibia and fibula) and especially for forearm or leg fractures in patients who are unconscious. A split catheter
is introduced into the compartment and the pressure is measured close to the level of the fracture. A differential pressure (ΔP) – the difference between diastolic
pressure and compartment pressure – of less than
30 mmHg (4.00 kilopascals) is an indication for immediate compartment decompression.
Treatment
The threatened compartment (or compartments) must be promptly decompressed. Casts, bandages and dressings must be completely removed – merely splitting the plaster is utterly useless – and the limb should
be nursed flat (elevating the limb causes a further decrease in end capillary pressure and aggravates the muscle ischaemia). The ΔP should be carefully monitored; if it falls below 30 mmHg, immediate open fasciotomy is performed. In the case of the leg,
‘fasciotomy’ means opening all four compartments through medial and lateral incisions. The wounds should be left open and inspected 2 days later: if there is muscle necrosis, debridement can be carried out; if the tissues are healthy, the wounds can be sutured (without tension) or skin-grafted.
NOTE: If facilities for measuring compartmental
pressures are not available, the decision to operate will have to be made on clinical grounds. If three or more signs are present, the diagnosis is almost certain (Ulmer, 2002). If the clinical signs are ‘soft’, the limb should be examined at 30-minute intervals and if there is no improvement within 2 hours of splitting the dressings, fasciotomy should be performed. Muscle will be dead after 4–6 hours of total ischaemia –
there is no time to lose!
HAEMARTHROSIS
Fractures involving a joint may cause acute
haemarthrosis. The joint is swollen and tense and the patient resists any attempt at moving it. The blood should be aspirated before dealing with the fracture.
INFECTION
Open fractures may become infected; closed fractures hardly ever do unless they are opened by operation. Post-traumatic wound infection is now the most common cause of chronic osteitis. The management of early and late infection is summarized under the section Sequels to open fractures (page 710).
GAS GANGRENE
This terrifying condition is produced by clostridial infection (especially Clostridium welchii). These are anaerobic organisms that can survive and multiply only in tissues with low oxygen tension; the prime site
