14.1 Musculoskeletal injuries in children

Musculoskeletal injuries in children have some unique characteristics and differences from those in adults. Injury to the growing skeleton may cause growth disturbance. While the injured adult has to recover from the trauma itself, children also need to cope with any implications of trauma to their growth.

Bone healing is faster in children and complications affecting bone healing rarer than in adults because the bone is more biologically active with a thick vascular periosteum.

The biomechanical characteristics of the growing skeleton are also different. Bone is more elastic and incomplete fractures, that are rare in the adult, often occur. The periosteum is loosely attached to bone while tendons, ligaments, and muscles are firmly attached to the periosteum. As a result, children suffer fractures more often than sprains, ligament ruptures, and joint dislocations. The biomechanical properties change with age and there are characteristic injury patterns for different age groups. Fractures involving the physis only occur in children.

The property of growing bone to remodel by asymmetric growth at the physes is also unique and age dependent. Overgrowth may complicate long-bone fractures in children.

Management of the multiply injured child follows adult principles but there are some differences that are essential for the treating physician to recognize. This also applies to the surgical treatment of children’s fractures: while some general principles are similar to those in the adult, certain characteristics exist which may often be crucial for the optimal management of young patients.

Finally, child abuse is discussed—a clinical entity unique in children. Suspecting and diagnosing child abuse is essential for the safety and future development of infants and young children.

Long bones begin to ossify in utero when the primary bone collar appears in the middle of the cartilage anlage. This region of primary endochondral ossification then expands and progresses towards the bone ends, establishing primary ossification fronts, the physes or growth plates, in both directions.

Vascular invasion of the hypertrophic cartilage inside this primary bone collar results in either direct cartilage resorption or a transient stage of endochondral bone formation followed by osteoclasis. The medullary canal and an endosteal surface are thus established.

The entire anlage continues to grow in length by the proliferation and ossification of cartilage at the physis. Further growth and development of the diaphysis are achieved by direct bone apposition and resorption on the periosteal and endosteal surfaces, respectively. Therefore there are two different processes that contribute to the final structure of a typical long bone: appositional cortical bone formation, mainly in the diaphysis, and progressive endochondral ossification at the physes, leading to cancellous bone formation. Only after birth (with the exception of the distal femoral epiphysis) will secondary centres of ossification form at a time characteristic for each epiphysis.

These processes lead to the development of the final structure of the growing long bone: the tubular diaphysis in the middle is made of cortical bone, the conical metaphyses on either side of the diaphysis, and the epiphyses at both ends consist of cancellous bone; the cartilaginous physes separate the metaphyses from the epiphyses.

Injuries involving the physis occur as a result of the unique structure of bone during childhood. The physis is biomechanically the weakest structure of the growing bone, particularly when shear forces are applied, and is therefore the most vulnerable to injury. Physeal injuries, their treatment, and their complications are discussed in Chapter 14.2.

Bone in children is biologically more active than in adults. Apart from the activity at the growth plate, the modelling process, where bone is continuously absorbed and replaced by new bone, is more active in children. These processes of growth and modelling are genetically determined but are also influenced by complex factors including circulating hormones, nutritional intake, mechanical influences, and disease. At the age of skeletal maturity, bone growth is completed but the modelling process—frequently referred to as remodelling in adults—continues at a slower rate. Overall the biological activity of bone reduces after skeletal maturity.

The periosteum plays an important role in the biology of the growing bone. It shows greater osteogenic potential in younger children and has increased vascularity compared to adult periosteum. This contributes to the overall increased vascularity of the growing bone.

As a result of the increased biological activity of the growing bone, fractures in children heal rapidly. This healing capacity is significantly dependent on age: fractures heal very rapidly in the newborn, less so in childhood, and reaches adult rates during adolescence. This generally accepted knowledge was confirmed in a clinical study in which the time required for union of fractures of the femoral diaphysis in children followed a log-normal distribution and the increment in mean time to union was 0.7 weeks for every year of age.

Bone healing and callus formation in children may follow a slightly different pattern compared to the adult. A study of the external periosteal callus using a scanning electron microscope, a transmission electron microscope, and a radiograph microdiffractometer, demonstrated that the rapid fracture healing in children is related mostly to brushite mineral deposition among the collagen fibres, while hydroxyapatite deposition is insufficient. In the adult, fracture repair relies on hydroxyapatite deposition among the collagen fibres. Deposition of brushite minerals in external periosteal callus in children may be compensating for the insufficient hydroxyapatite mineralization, thereby making fracture repair more rapid in children than in adults.

When radiological fracture union criteria and staging are used, the pattern of healing in children is similar to that in the adult. Radiographic criteria can be used to date fractures. The length that each stage takes is age dependent but not sex dependent.

Increased biological activity of the growing bone leads to a lower incidence of complications related to fracture healing. Delayed union, infection, and non-union have all been reported as a result of high-energy trauma and open injuries. Furthermore, displaced intra-articular fractures and/or soft tissue interposition within the fracture may lead to delayed or non-union.

The incidence of these complications in adolescents is similar to that in adults. Children under 12 years of age are at lower risk of developing any of these complications. The actively osteogenic periosteum and the overall increased vascularity of the growing bone account for this.

Current knowledge and understanding of fracture-healing complications in children is based on a number of clinical studies. In the absence of segmental bone loss or extensive soft tissue loss requiring major reconstruction, healing in children can be expected within 6 months after open lower-limb fracture, with younger children healing more quickly. Union times for open tibial fractures are prolonged relative to closed injuries in similarly aged children, but bone grafting is seldom required. Delayed union is often a problem in children older than 11 years, while leg length discrepancy can complicate tibial fractures in children under the age of 11 years.

When a delayed or non-union occurs they are often associated with infection. The incidence of infection is also age related, being a rare complication in young children. Chronic osteomyelitis following acute wound infection after an open fracture in the lower limbs is also rare in children, and its incidence has been reported at 2–3%. The prevention of wound infection should follow the same principles as in adults: thorough immediate and, if necessary, repeated debridement and irrigation of the wound, stabilization of the fracture, and intravenous administration of antibiotics. Primary wound closure in the treatment of selected non-contaminated open fractures has been suggested, although the issue remains controversial.

Compartment syndrome following open injuries of the lower extremity is less frequent in children than in adults but it is important to recognize that it may occur in 2–4% of cases. Early fascial release is necessary to prevent the long-term consequences of unrecognized compartment syndrome.

Open fractures of the forearm and humerus in children are more frequently associated with healing-related complications. Delayed union, non-union, refracture, and malunion complicate about 25% of cases. Open type II and III fractures of the radius and ulna are at the highest risk. Excellent or good long-term results can be anticipated in 90% of all open fractures of the arm.

There are several structural differences between growing and mature bone that account for their differences in biomechanical behaviour. Mature bone has a higher density, and growing bone more porosity due in part to increased vascularity. The increased porosity may be one of the reasons why fracture propagation is less likely to occur in growing bone and fracture comminution is more common in adults than in children.

Woven bone predominates in the neonate and is gradually replaced by lamellar bone as haversian systems develop and osteons assume a longitudinal orientation. The stiffness, strength, and resistance to stress of bone increases with increasing age.

In the metaphyseal area, the cortex is thinner and perforated with more vessels, while the haversian systems develop close to skeletal maturity. This area can fail under either tension or compression in children, while in adults it is much more resistant to compression forces.

The epiphysis becomes increasingly stiffer as secondary ossification centres develop and its response to stress and strain alters with age. The development of subchondral bone over the physis changes the biomechanical characteristics of the area even further. This explains why different patterns of epiphyseal fractures occur in different age groups.

The periosteum is thicker and stronger in children. It is loosely attached to the diaphysis and separates from it easily in the case of a fracture. For this reason, complete circumferential rupture of the periosteum is rare in children and usually a significant part of the periosteum remains intact. This remaining periosteal ‘hinge’ prevents severe displacement of the fracture and aids reduction. The periosteum is more firmly attached to the metaphysis where it blends into the perichondrial ring that surrounds the physis.

Muscles are attached to the periosteum, while tendons and ligaments blend into the fibrous regions of the metaphysis, perichondrial ring, and epiphysis. With few exceptions, no soft tissue structures are directly attached onto bone. The periosteum, together with all its soft tissue attachments, adds significantly to the overall stability of the bone. The loose attachment of periosteum to bone, the intrinsic mechanical weakness of the physis, and the firm attachment of ligaments, tendons, and muscles to periosteum, all contribute to the fact that sprains, ligament injuries, and joint dislocations are rare in children, while physeal injuries are common.

There is experimental evidence that children’s bone have a lower modulus of elasticity, a lower bending strength, and a lower mineral content. However, children’s bone can deflect and absorb more energy before breaking by undergoing plastic rather than elastic deformation. The considerable plastic deformation occurring before the fracture starts may be due to multiple shear cracks opening up within the bone.

Furthermore, children’s bone breaks at a lower load than adult bone and so the stress in the bone is less. The energy required for the fracture to be propagated through the bone comes mainly from the strain energy. Children’s bone undergoes plastic deformation prior to fracturing, and therefore the bone in the region of the fracture will have yielded and have little strain energy.

Both of these factors—the small amount of strain energy available at the beginning of fracture and the difficulty a fracture has in propagating straight across the bone—tend to produce incomplete fractures in children.

Greenstick fractures are incomplete fractures produced by angulatory forces. The periosteum and cortex on the tension side are disrupted, while on the opposite side the cortex may be compressed or bent but remains in continuity. Greenstick fractures usually occur in the metaphyseal region of long bones but can occur in the diaphysis of long bones in neonates and young children (typically in the forearm).

Completion of the fracture with manipulation as well as simple manipulation to correct the angulation have keen supporters. This is a subject of debate since both methods have disadvantages. Completion of the fracture produces instability, makes immobilization more difficult, and increases the risk of late displacement. Simple manipulation of greenstick fractures of the diaphysis can lead to incomplete consolidation on the tension side of the injury, which may lead to refracture.

These are incomplete fractures of the metaphyseal region due to axial compression forces. The metaphyseal cortex, which is thin in childhood, gives way usually on one side. The fracture appears as a ‘kink’ in the cortex and minimal angulation may also occur. Typical sites include the distal forearm and the tibia. Buckle fractures occur in young children only. In older children similar injuries produce compression metaphyseal fractures. Treatment may be required to correct any significant angulation.

Angulatory or longitudinal forces applied to the immature bone may cause deformation beyond the limit of elasticity but below the fracture point. Plastic deformation then occurs without an apparent macroscopic fracture. Microfractures may occur on the tension side but are not apparent on radiographs. This type of injury occurs in young children and typically in paired bones. Usually one of the bones fractures and the other deforms. Plastic deformation may be missed but should be suspected when one of the paired bones is fractured and the other is apparently intact. Periosteal reaction does not usually follow plastic deformation.

Correction of the deformity with manipulation is difficult and may result in a complete fracture but is often necessary in order to reduce a fracture or dislocation of the paired bone.

Stress fractures may occur in older children and adolescents. They are usually associated with increased and repetitive physical activity and typically occur in the tibia, fibula, and femur. They heal quickly, with modification of activities and immobilization, by extensive periosteal reaction and abundant callus formation. Careful history, physical examination, and radiographs can help diagnose most common stress fractures and differentiate them from infection or neoplasm that would need aggressive treatment. Magnetic resonance imaging (MRI) scanning can also help establish the diagnosis and negate the need for histological diagnosis.

In developed countries, injury has become a leading cause of childhood morbidity and mortality. Musculoskeletal injury is one of the more important groups associated with high morbidity and mortality. The overall estimated annual incidence of limb fractures requiring hospital treatment in the age group up to 16 years is 0.5–1%. The age group of 4–11 years is at the highest risk. The sex distribution shows a male predominance in the range of 2–3:1 which increases with age and becomes 5.5:1 in adolescence.

Epidemiological studies on fracture incidence from different parts of the world show considerable variation because of cultural, socioeconomic, demographic, and other population characteristics. Despite this variation, there is overall agreement that the pattern, site, and frequency of childhood fractures all depend on age.

During birth, fractures of the clavicle, skull, and proximal humerus can occur. Fractures within the first 2 years of life are rare and should raise suspicion of metabolic disease or non-accidental injury. Greenstick and torus fractures occur in early childhood while fractures in adolescence follow a more adult pattern.

The secondary ossification centres appear at an age characteristic for each epiphysis, the increasing size changes the biomechanical characteristics of the epiphysis, making it stiffer. As a result, different epiphyseal fractures occur at different ages.

Upper-limb injuries in children are more common than lower-limb ones and the non-dominant side is at higher risk. Fractures of the forearm are the most common in all age groups with a peak between the years of 8–16. Clavicle fractures as well as hand and phalangeal fractures are frequent in all age groups. Supracondylar fractures of the humerus usually occur between the ages of 4–7 years. Tibial fractures occur in all age groups but the pattern of fracture is different: toddlers’ fracture between the ages of 2–5 years, and spiral or physeal fractures in the older age groups.

Multiple, high-energy, and open fractures are relatively rare in children compared to adults, and they usually result from road traffic collisions. Seasonal variations are also noted with summer usually being the peak period for childhood trauma. The relatively high prevalence of fractures resulting from bicycle or pedestrian injuries in adolescents has been highlighted recently.

Ligament injuries and joint dislocations are rare in young children but reach adult frequency close to skeletal maturity.

In the growing skeleton, ligaments, tendons, and muscles are firmly attached to the periosteum. In the epiphyseal region and particularly around the physis periosteum is firmly attached on bone. Tensile forces to ligaments and tendons in this region lead to the failure of the weakest biomechanical structure, namely the physis. With this mechanism of injury, therefore, whereas an adult would suffer a ligament rupture or joint dislocation, a child sustains a physeal fracture.

Dislocations can occur in children. The elbow or the radiocapitellar joint is the most frequently affected joint; other joints include the hip, knee and the proximal tibiofibular joint.

Ligament injuries around the ankle are rare, while physeal fractures are more common. The ligaments of the knee are also infrequently injured and tibial spine avulsion rather than anterior cruciate ligament rupture is a typical example. Also characteristic of the different behaviour of the growing skeleton is the low incidence of 4% of knee ligamentous instability associated with femoral fracture; in the adult this incidence is in the range of 40–70%.

Children tend to regain full range of movement quickly after removal of casts and splints and physiotherapy is rarely needed. However, some particular types of intra-articular or physeal fractures in children may lead to permanent loss of full range joint motion despite treatment.

Articular cartilage in children does not differ from the adult. The superficial layers of the growing epiphyseal cartilage develop into adult-type hyaline cartilage and lose the ability to transform into bone or heal after injury. The recovery expected following damage to the articular cartilage should therefore be similar to that in adults.

There is no documented evidence that healing of soft tissues following penetrating or blunt trauma is faster in children than in adults or that complications after such injuries are rarer. Musculoskeletal injuries should always raise suspicion of neurovascular damage and this usually responds better to early intervention. Compartment syndrome is also associated with some paediatric fractures and decompression may be needed to avoid Volkmann’s ischaemic contracture.

Fractures may heal in a non-anatomical position. It is well recognized that the growing skeleton has, to a certain extent, the capacity to correct residual deformities after a fracture has healed and this process is usually referred to as remodelling. The remodelling potential differs according to the location of the fracture, the severity of its residual deformity after healing, and the skeletal age of the patient. Decisions upon the acceptability of a residual deformity have to be based on knowledge of the remodelling potential of the individual fracture so that unnecessary treatment or acceptance of a malunion should be avoided.

During fracture healing and remodelling in children, bone growth acceleration may occur. This overgrowth phenomenon has to be taken into account when treating fractures, particularly those in the lower limb.

Remodelling of adult fractures occurs at the site of the fracture and follows Wolf’s law: alteration in the mechanical environment, as a result of bone deformity, leads to new bone formation on the concave side (compression) and bone resorption in the convex side (tension). In adults this is a slow process and little correction of deformity can be expected.

The Heuter–Volkmann law suggests that, in children, the physis tends to align itself perpendicular to the resultant force acting across it by a mechanism of asymmetric growth. In the presence of an angulatory deformity, therefore, the physis would grow faster on the concave side of the fracture and would reorientate the joint and, eventually, the fracture.

The hypothesis of asymmetric physeal growth has been confirmed in animal experiments including radiological and histological studies. The overall alignment of the malunited bone corrects rapidly as a result of asymmetric growth at the epiphyseal plates. The joints at both bone ends regain their normal alignment with this mechanism. The angulation at the fracture site corrects slowly as a result of both asymmetric physeal growth and local remodelling at the fracture, following Wolf’s law. Local remodelling accounts for only 25% of the correction at the fracture site, the remaining 75% of correction being achieved by asymmetric physeal growth (Figure 14.1.1).

The exact mechanism of deformity correction by asymmetric physeal growth is not known. The role of the periosteum has been investigated but results were discouraging: experimental periosteal division to release tension has little effect on deformity correction. Mechanical factors may play a role but do not solely control the mechanism of correction: experimental studies demonstrated femoral overgrowth in animals with tibial fractures, suggesting a systemic factor contributing to the correction mechanism.

Rotational moments applied on the physis may induce helical growth, which in turn may be responsible for the correction of torsional deformities following fractures. The same mechanism may be responsible for the development of late secondary torsional deformities following fractures healed with angulation.

Experimental findings on asymmetric physeal growth in malunited fractures are supported by clinical evidence. Measurements on radiographs of malunited forearm fractures showed most of the angular correction to occur at the growth plate. Furthermore, children over the age of 11 years do not show the same potential for correction of deformities and are closer to adult patterns of remodelling. The physis still shows some potential in correcting the orientation of the joint but this does not contribute substantially to the correction of the fracture angulation.

In clinical practice, knowledge of the remodelling potential of the specific fracture concerned is important. Precise guidelines are not available and, in clinical practice, a lot relies on the personal experience and training of the treating surgeon. This may lead to overtreatment of some fractures with good remodelling potential, or acceptance of deformities that are not going to remodel and may cause functional problems. Some attempts have been made to determine the factors that influence the remodelling potential in general and also to define guidelines for some specific fractures.

The age of the patient influences the potential for remodelling. In young children under the age of 2 years, angulations of up to 90 degrees in femoral fractures remodel well. This potential decreases with age to the degree that little remodelling should be expected after the age of 11 years. Since correction of deformity relies mainly on asymmetric physeal growth it is only logical that the younger and more active the physis, the greater the potential for remodelling.

The distance of the fracture from the physis also influences remodelling potential. Metaphyseal fractures remodel better than diaphyseal ones. Radiographic studies of malunited forearm fractures have confirmed that midshaft radial fractures have less potential for correction than distal radial ones. Epiphyseal fractures, and particularly intra-articular ones, have little potential for deformity correction.

The severity of the residual deformity once fracture healing has been accomplished also plays an important role. The more severe the deformity, the less potential it has for complete remodelling. With the exception of some fractures that present late with deformity, the healed position is similar to the one accepted at the end of treatment. A 20-degree angulation of a femoral fracture is acceptable up to the age of 13 years, but this would not be the case for a tibial fracture.

The plane of movement of the adjacent joint in relation to fracture angulation also influences remodelling. Deformities in the plane of movement of the adjacent joint remodel better than ones at an angle to this plane.

Proximity of the fracture to the end of the bone with the most active physis appears to favour remodelling. For example, the radius relies a lot more on its distal than its proximal epiphysis for longitudinal growth, and therefore fractures of the distal radius remodel better than those of the proximal radius. Correction of rotational deformities varies in different parts of the skeleton. It is generally less optimal than angular remodelling, despite experimental evidence of helical growth of the epiphyseal plate under rotational moments. The proximity of the fracture to a joint with multiplanar movement may be playing a role. Proximal humeral fractures appear to remodel their rotational deformities well. The question, however, is whether the humerus shows true rotational improvement or the rotational malalignment is compensated for at the glenohumeral joint.

Acceleration of growth following long-bone fractures in children is a well-recognized phenomenon. There is experimental evidence that this overgrowth occurs at the epiphyseal plates but the exact mechanism of physeal stimulation is unknown. Femoral fracture in the rabbit also stimulates ipsilateral tibial overgrowth. At the end of this process the femur is overgrown by 2% of its length and the tibia by 1%.

Radiographic measurements show that, in femoral fractures, growth acceleration reaches its maximum at about 3 months after the fracture. It is significantly higher than normal for about 2 years and then slows down but is still higher than normal until about 4–5 years after the fracture. The uninjured ipsilateral tibia follows the same time-pattern but overall its overgrowth is slower. A fractured tibia shows growth acceleration but does not influence the ipsilateral femur. Bone scintigraphy studies have demonstrated increased growth plate activity in the distal femoral and proximal tibial growth plates following femoral fracture. Recent evidence suggests that this may be due to increased mitotic activity at the growth plate, rather than increased vascularity as it was initially thought.

Growth acceleration is higher when there is overlap of the fracture ends. When there is little or no overlap between fragments the increase of the growth rate is minimal and results can be predictably good with leg-length discrepancy of 0.5cm or less at the end of growth. The average overgrowth following femoral fractures—with or without overlap of the fracture ends—is less than 1cm but can reach 2.5cm in some cases.

Overgrowth is also age dependent, with the 4- to 7-year-old age group being most likely to show significant growth acceleration. An increased effect on boys has been reported but a much larger proportion of boys than girls in the 4- to 7-year-old age group were included in this study.

Injury is the leading cause of children’s morbidity and mortality in developed countries. Road traffic collisions and falls account for 80% of childhood trauma. Multiple injuries and multisystem involvement is frequent because of the small size of the young patients. The order and priorities in the assessment and management of the multiply injured child are the same as in the adult. However, there are unique characteristics in children that require particular attention and these are analysed in the following section.

Priority should be given to the treatment of life-threatening injuries and limb-threatening injuries should follow. Errors in the management of ventilation and circulation, or failure to detect hidden injuries, are the most common causes of preventable death.

Because of the small body mass in children, there is a greater force per unit of body area during injury. Furthermore, because of the proximity of multiple organs, multiple system injury is frequent. This is often the case with the abdominal viscera which are not well protected by the poorly developed abdominal musculature. The head is large relative to the trunk; therefore it is injured in 80% of multiply injured children and is often the leading contact point.

Age- and size-appropriate equipment is also needed for the treatment of injured children. Drug doses and some equipment size determination are based on body weight.

The skeleton in children contains less mineral than in the adult and is therefore more elastic. In multiply injured children, soft tissue and visceral injuries may occur without concomitant bony injuries. For example, the thoracic cage is very elastic and rib fractures are rare. Lung injury with little external evidence may occur and mediastinal injury is not uncommon.

Children have a higher ratio of body surface area to body volume. As a result, they are more prone to thermal energy loss, particularly in the presence of hypovolaemia.

The emotional instability of the injured child, together with difficulty in interacting with unfamiliar individuals makes communication difficult. Obtaining a history of the injury may be a challenge and cooperation of the young patient is not always available. Psychological and emotional support in the acute phase as well as during recovery are important in order to prevent long-term effects of psychological injury.

Some of the beneficial features in children with multiple injuries include the low incidence of pre-existing disease, the high capacity for recovery from central nervous system injury, and the larger cardiac and pulmonary reserves. Their vascular system can maintain normal systolic pressure despite significant hypovolaemia by reflex tachycardia and vasoconstriction. However, with ongoing blood loss the body can no longer maintain normal blood pressure and haemodynamic deterioration in children is usually rapid.

Injury may have long-term effects on growth and development. Unlike in the adult, the child’s temporary disability as a result of trauma may lead to long-term disability as a result of growth disturbance or abnormal development. Treatment should aim at helping the child not only to recover from the injury but also to continue the normal process of growth.

Transport and triage in multiply injured children follows the same principles as in adults. Paediatric trauma scores have been developed to facilitate triage and offer a prediction of outcome (Table 14.1.1). The Revised Trauma Score, often used in adults, is not applicable in children, particularly young ones whose verbal communication is poor. The Paediatric Trauma Score is often used in trauma centres and is presented here.

Each variable is given one of three scores and the total score can vary between –6 and +12. Children with a score higher than 8 have better prognosis with usually preventable mortality, morbidity, and disability. Ideally, children with a score below 8 should be triaged to specialized centres with experience and facilities for paediatric trauma. The Paediatric Trauma Score has been evaluated and has been found to be predictive of outcome in multiply injured children.

The same principles of resuscitation as in the adult apply in children and Advanced Trauma Life Support methodology is used in most major trauma centres.

Cervical spine control during this is important. The incidence of cervical injury in children is lower than that in the adult. However, children have a larger occiput, and lying on a spinal board may produce significant flexion of their cervical spine and/or obstruct their airway. Modified spinal boards with a recess for the occiput or a pad to raise the chest have been suggested. Orotracheal intubation in children is usually performed using an uncuffed tube. A guide for the size of the appropriate tube is the size of the little finger.

Managing circulation also follows the adult principles. It is useful to remember that the circulating blood volume of a child is 80mL/kg body weight. An estimate of the child’s weight is given by the following equation:

In children, hypotension occurs when blood volume loss is in excess of 45% and the patient can rapidly deteriorate and become comatose. It is important to remember that vital signs are age dependent: an infant can normally have a pulse rate of 160 beats per minute, a blood pressure of 80mmHg, and 40 respirations per minute, while for an older child these values would correspond to hypovolaemia and shock.

An alternative method for fluid resuscitation in children under the age of 6 years is intraosseous infusion. The proximal tibial or distal femoral metaphysis can be accessed but infusion in the proximity of fractures should be avoided. Infusion rate is similar to intravenous rate.

Urine output is age dependent and this should be remembered when assessing circulation in the injured child. Output is 1–2mL/kg/h in infants, 0.5–1mL/kg/h in children, and 0.5mL/kg/h in adolescents.

Part of the resuscitation protocol includes assessing the neurological status of the patient. A paediatric modification of the Glasgow Coma Scale is used for this purpose (Table 14.1.2). The ‘best verbal response’ part of the scoring is the only variable which has been modified.

Musculoskeletal injuries are common in the multiply injured child, with fractures of the long bones of the lower limb and the humerus being the most frequent. About 10% of the fractures in polytrauma are open. Central musculoskeletal injuries, involving the clavicle, scapula, spine, or pelvis, are more often associated with low trauma scores, long hospital admission, complications, and mortality. Early diagnosis helps in reducing the morbidity and mortality of these injuries.

Musculoskeletal injuries can be missed in the early stages of resuscitation and management. The priority of treating potentially life-threatening conditions is often the reason for overlooking skeletal trauma. Furthermore, imaging of the immature skeleton may often be more challenging.

Treatment options in children are largely similar to those in the adult. External immobilization or internal fixation are the two main forms of treatment and each has a variety of alternative methods available.

Traction, skin or skeletal, using different frames and devices has been the treatment of choice for many fractures. However, this requires prolonged hospital admission and close supervision, both clinical and radiographic. The impact of the prolonged hospital admission on the young patient’s psychology, the family implications, and other socioeconomic factors have now made traction a less favoured form of treatment.

Plaster cast immobilization, with or without previous manipulation and reduction of the fracture, is the treatment of choice for a large number of paediatric fractures. Immobilization of adjacent non-injured joints has very low morbidity in children who, almost without exception, recover full movement soon after removal of casts. Loss of fracture position ischaemia due to soft tissue swelling, and poor cast application are potential complications.

Functional bracing is an alternative external immobilization method for some fracture types. This allows joint movement while providing some stability to the fracture. Functional braces for the long bones of the upper as well as the lower extremity have been suggested.

A number of fractures in children are optimally treated with K-wire fixation following closed or open reduction. While this method is often insufficient for fixation of adult fractures, it works well in children where deforming forces are weaker and fractures heal faster. K-wire fixation is often supplemented by plaster casts. Wires are left prominent through the skin and do not usually require a second anaesthetic for removal. Potential complications include pin tract infection, ectopic ossification, and migration. Biodegradable pin fixation has been suggested as an alternative to avoid these complications. Polyglycolic acid pins are buried into bone and the risk of infection, ectopic ossification, or the need for further anaesthesia are much lower. They offer similar quality of fixation with ordinary K-wires but their insertion is technically more demanding.

Flexible intramedullary nails have become the treatment of choice for most long-bone fractures in children. The fracture site is not exposed, periosteal stripping is avoided, and stability is adequate for the low level of loading that is present in children. Overgrowth or malunion have not been observed and the only reported complication is skin ulceration at the ends of prominent nails, requiring early removal. Flexible nails offer optimal treatment for multiply injured children where fast and adequate early stabilization is essential. The use of external fixation devices is indicated mostly in open fractures with extensive soft tissue damage and/or bone loss. Open reduction and internal fixation with plate and screws is indicated in intra-articular and metaphyseal/epiphyseal injuries where anatomical reduction is essential.

Absolute and relative indications for surgical treatment of children’s fractures vary between centres. Specific experience with paediatric fractures is necessary for correct decision-making upon surgical treatment. Absolute and relative indications for surgical treatment are shown in Table 14.1.3 and discussed in the following sections.

Open fractures require surgical exploration and debridement to prevent infection. All grades require attention and intervention. Grade I fractures with minimal skin laceration may be complicated by anaerobic infection or compartment syndrome and need prompt exploration. Stabilization of the fracture and soft tissue coverage where appropriate are also essential.

Multiply injured children with multiple long-bone fractures require surgical stabilization. This makes nursing and rehabilitation easier and facilitates treatment of other systemic injuries.

Neurovascular damage to the fractured limb, requiring repair, is an indication for surgical treatment to provide stability and facilitate repair. Vascular supply to the limb may be obstructed by the displaced fracture and limb oedema, without vascular injury. Fracture reduction facilitates blood flow through the vessel. At times, however, a vessel or nerve may be trapped into the fracture and attempts at closed reduction may cause further neurovascular injury.

Displaced intra-articular fractures do not remodel and require anatomical reduction and stabilization. Furthermore, the majority of these fractures in children are at the same time complex physeal fractures (type III or IV) which carry the potential of growth disturbance. This adds to the indication for anatomical reduction and stable fixation.

Older children who are close to skeletal maturity and have little remodelling potential should be treated as adults. When all the indications for surgery listed here are considered, the age of the child should be taken into account first as it represents the single most important factor influencing the final decision.

Children with conditions such as neuromuscular disorders which result in muscle spasticity, fracture immobilization, and maintenance of reduction may often be a challenge. Fixation of the fracture may offer an uneventful recovery and rehabilitation. Children with metabolic bone disease or skeletal dysplasias may also require particular attention and conservative treatment may be inadequate.

Late intervention may be required when early conservative treatment has failed. Failure of the fracture to produce early callus may be due to soft tissue interposition and may require surgical intervention.

There are fractures in specific locations in the skeleton that are prone to non-union. Furthermore, fractures at sites of muscle or tendon attachment may be inherently unstable and often require fixation.

Pathological fractures may need excision of the bone lesion and grafting, depending on the underlying pathology. Fixation may also be required in cases of instability or in high stress areas. Histological diagnosis is essential before proceeding with fracture fixation.

Physicians involved in the care of children at any level should be aware of the possible diagnosis of non accidental injury and have a high index of suspicion when infants and young children are involved. In cases where the diagnosis of child abuse is missed and patients are discharged from hospital care, the risk of further non accidental injury is 20% with a 5% risk of lethal injury. The majority of deaths from injury under the age of 1 year are the result of child abuse.

In order to avoid missing the diagnosis or overdiagnosing child abuse, standard hospital, regional, and national protocols and guidelines for suspected child abuse that involve senior medical personnel with experience in children from the early stages of the procedure are necessary. All health care professionals who interact with children should be aware of these protocols and report any suspected cases of non-accidental injury through the appropriate channels.

An unsettled family environment with immaturity or emotional instability of the parent(s), failure to cope with the crying baby, failure to establish bonding, drug and alcohol abuse, and social deprivation may increase the likelihood of non-accidental injury. However, it is not necessary for any of these factors to be present and incidents of child abuse may present in apparently settled and happy families. In an analysis of non-accidental injuries leading to death, no risk factors within the families could be identified. There was no recognizable pattern in the age and sex of the abusers, nor their ethnic origin and social and marital status.

Indications in the presentation and history of the injury may raise a suspicion of child abuse. The mechanism of injury as described by the parents/guardians may not fit with the degree and nature of the resulting injury. The history may differ between parents/guardians or discrepancies may exist when the history is repeated. A significant delay in seeking medical advice should raise suspicions. This is not necessarily true with subtle injuries, such as undisplaced greenstick fractures, but it is unusual for complete long-bone fractures not to be noticed.

Repeated injuries in the same child, particularly when treated at different places, poor compliance with treatment, and non-attendance at follow-up appointments may be indicative of abuse.

The typical ‘battered child syndrome’, as described by Caffey, includes a combination of multiple fractures at various stages of healing, subdural haematoma, failure to thrive, soft tissue swellings, and skin bruising. Some of the musculoskeletal injuries, although not unique, may be characteristic of the abused child and raise suspicions. Since the original recognition and description of child abuse, the patterns have changed with subdural haematomas and fractures being present in a smaller percentage of patients. In a recent epidemiological study, however, the most common non-orthopaedic injury was found to be the injury to the head, with or without skull fracture. The most common fractures were those of the femur and humerus.

Fractures occur in a relatively small percentage of abused children, probably in the range of 10–15%.

Characteristic metaphyseal injuries include the chip fracture with periosteal avulsion and irregular/diffuse metaphyseal changes, while complete physeal separation is rare. Impaction and buckle fractures may occur, but these are also common in accidental injuries.

Metaphyseal injuries in children occur from indirect shear forces applied when the extremity is pulled, pushed or twisted, or when the infant is shaken. The fracture occurs proximally to the physis and a disk of bone is avulsed from the metaphysis. This disk has a peripheral margin that is thicker and denser than its central part, as a result of its protection by the subperiosteal bone collar at the chondro-osseous junction. The peripheral margin is therefore the most conspicuous component of the fracture which, when viewed tangentially, results in a corner-fracture (chip fracture) appearance and when viewed obliquely results in a bucket-handle appearance.

Diaphyseal fractures and spiral humeral fractures under 2 years are highly suspicious; the most common and transverse ones may be more common than spiral. Abundant callus formation, with or without gross deformity, is often seen due to the lack of fracture immobilization. Furthermore, several fractures at different stages of healing are characteristic.

Periosteal elevation is often seen in the metaphysis or diaphysis of long bones. However, normal infants may have symmetric long-bone periosteal elevation with double-cortex appearance persisting up to the age of 2 years.

Rib fractures, otherwise uncommon in children, may be seen in cases of abuse. Skull fractures and widened sutures are characteristic and spinal injuries may be observed.

The vast majority of abused children have soft tissue injuries. The age of the child is an important parameter when studying soft tissue injuries. Infants rarely present with soft tissue injuries after accidents. Abused infants have at least one major soft tissue injury at presentation, the head and face being the most common location. Abused children over the age of 3 years usually present with three or more soft tissue injuries. Head and face injuries, and particularly perioral trauma, are also common in this age group.

Burns should also raise suspicions, particularly the round, sharply demarcated burns from cigarettes or third-degree burns in areas that are not usually exposed. Rope marks or linear ecchymoses are also characteristic. Visceral rupture without a history of major blunt trauma and trauma to the perineum and genitalia should also alarm the physician.

History and clinical examination is the cornerstone of diagnosis of child abuse. If suspicion is raised, a senior physician with experience in children, usually a paediatrician, should be involved as part of a standard hospital procedure. All injuries should be recorded carefully and clinical photographs should be obtained for any external injuries. An impression of the family background and the rapport between child and parents/guardians should be established.

Further investigations may include radiographs and blood tests. Radiographic examination of clinically suspicious areas for new or old fractures is often sufficient. A complete skeletal survey is needed in cases of uncertainty and often in young infants. Isotope bone scans can create confusion because of the presence of the physes.

Determining the age of fractures and soft-tissue injuries is often important in order to establish the diagnosis of non-accidental injury. The radiographic appearance of a healing fracture depends on the age of the fracture and the age of the patient. Knowledge of the expected speed of healing and the corresponding radiographic appearance is important. Furthermore, the degree of soft tissue swelling at first presentation indicates how recent the injury is and may indicate delay in seeking medical advice.

A full blood count is necessary to exclude iron-deficient anaemia, leukaemia, and other haematological conditions that may cause bruising and petechiae. Coagulation tests to exclude haemophilia may also be needed. Copper level in serum can be ordered when multiple epiphyseal spurs are observed on radiographs. The differential diagnosis of child abuse is summarized in Table 14.1.4. Child abuse should be differentiated from conditions that cause multiple fractures or multiple soft tissue bruising.

Type IV osteogenesis imperfecta remains the most difficult type to differentiate because of its mild clinical presentation and the absence of blue sclerae. Collagen testing is available in specialized centres and can sometimes be helpful.

The diagnosis of one of the discussed conditions does not necessarily exclude child abuse, as these may coexist.