14.7 Children’s hand trauma

Soft tissue injuries and lacerations are the most common paediatric hand injuries, most of which are the result of the fingertip being crushed. Fractures, followed by burns, bites, and infections are the next most frequent.

The incidence of the various injuries and subtypes of injuries varies with age. Babies suffer scalds, toddlers from soft tissue injuries and crush injuries, with burns also being common in this age group. Older age groups have a higher incidence of fractures, and to a lesser extent lacerations with damage to the underlying longitudinal structures.

Injuries usually occur at home, with a higher incidence in boys.

In young children, it is important to gain the confidence of the child and parents. Time should be taken to allow the child time to look and assess you, whilst you look and assess them. Speak to both the child and parents to obtain the history and establish rapport. It helps to bring a toy, penlight, or other distraction device to draw the attention of the child. If the child is sitting on a parent’s lap, examine them there. Crouch down to their level rather than standing over them.

When possible avoid causing the child any pain. A history of the accident may at times provide sufficient independent reason for surgical exploration making it unnecessary to examine the hand or view the wound prior to theatre. Although wound examination may allow better assessment of injured structures and hence communication, it will not usually change the decision to operate. If a dressing must be removed do this after as much of the examination has already been completed. Examination may require heavy reliance on observation and indirect methods such as the tenodesis effect. Consider examining the child’s unaffected hand to gain their confidence. Much of the examination can be done by observation of the child playing or trying to hold objects. Observe their hand’s posture and movement. Ask them to open or close their fingers of both their hands together. Sensation is extremely difficult to assess even in older children, as they will believe they are feeling something even if they cannot. Trying to assess sensation with them blinded is difficult and unreliable. The wrinkling test following water immersion (denervated areas fail to wrinkle) may be useful, but is time consuming in the clinic. It is much better to observe the hand immediately after any dressing has been removed, as many hands will be moist beneath their dressings and will demonstrate the wrinkling sign. Dryness and sheen of the skin as determined by palpation or by the tactile adhesion test (gently slide a pen against their skin and assess the degree of friction), are often later signs of denervation and may not be that useful in the acute setting.

Movement often provokes pain, hence leave this component of the examination until last. Children can often be encouraged to open and close their fingers. If children are uncooperative then compression of the forearm musculature produces movement of the digits. Failure of movement may indicate a tendon injury. Partial injury can be suspected when there is painful movement. If the injury is distal to the wrist then the tenodesis effect of differential digital tendon gliding on passive wrist flexion and extension can provide evidence of tendon injury or continuity. If there is any doubt then surgical exploration is indicated, as the long-term consequences may be severe.

Where dressings are indicated in younger children, it is usually easier to dress the whole hand in a boxing glove type bandage, as this is more difficult for children to remove. Usually, it is not necessary to extend the dressings above the elbow or to plaster them. The additional weight and discomfort of a plaster cast gives the child extra incentive to wriggle out of these extended dressings. A boxing glove bandage wrapped with tape preventing use of the fingers is very effective. To prevent the bandage becoming dirty, wet, or removed, the parents may apply a sock over the bandage, which can be changed as required.

When suturing children’s skin always use absorbable sutures, as this obviates the need to distress the child further by suture removal and avoids an additional anaesthetic. 5/0 or 6/0 Vicryl Rapide is usually rubbed away within several weeks, but may last longer.

Accident awareness and prevention should be an important part of general health care. Several projects increasing such education are proving successful in reducing injuries.

Non-accidental injury (NAI) to children’s hands should be suspected when the pattern of injury does not seem to follow the explanation given by the parents or differs from the explanation given by the child or changes with each telling. Burns are the commonest presentation of NAI in the hand. Recurrent presentations or admissions should alert one to the possibility of NAI.

The consequences of such an accusation are severe, so do seek further opinions, and repeat the history and examination several times over the ensuing days as well as reviewing the records and relevant x-rays before making a diagnosis of NAI.

Crush injuries to the fingertip are extremely common injuries, often occurring when the fingertips of toddlers and younger children become jammed in the hinge side of a closing door. The mechanism is an off-step crushing force that presses on the nail plate on one side and on the pulp on the other. The usual result is a fracture or avulsion of the nail plate, associated with an underlying nail bed laceration, lateral perionychial lacerations, and an underlying tuft fracture of the distal phalanx or a Salter–Harris type I fracture of the distal phalanx physis (Seymour’s lesion). Different patterns of the injury depend on the distribution of the force. Crush injuries most commonly involve the longer ring or middle fingers; however any finger may be injured. Complete amputation including bone is uncommon, but tip avulsion is common.

Deformity of the nail and fingertip is common following conservative therapy (Figure 14.7.1A,B). Operative treatment requires local or general anaesthesia depending on the age of the patient. The operation involves removal of the damaged nail and meticulous repair of the lacerated nail bed and surrounding skin. The nail bed is repaired with the finest absorbable sutures available, usually 7/0 or 8/0 Vicryl, using microsurgical instruments and loupe magnification. Where nail bed loss is present the defect can be closed by excision and direct suture or by using a graft. The graft may be nail bed graft harvested from the adjacent remaining nail bed, from a toe nail bed, or may be a dermal graft. Once repaired the previously removed nail, silicon sheeting, or piece of foil suture packet is applied as a nail splint, covering the nail bed and maintaining the nail fold. Dressings are applied and left for 2 weeks, following which no dressings are needed. Nail growth will take around 6 months before the result can be assessed (Figure 14.7.1C).

Where avulsion of the fingertip has occurred, the tip frequently contains one or more tiny fragments of distal phalanx tuft. These should be debrided, as if they remain they frequently become infected or resorb. If the avulsed segment is still tenuously attached or is brought in with the patient, it should be replaced. This should be performed within 5h of injury for the maximal chance of success. Once the delay is greater than 5h, the pulp portion should be defatted prior to replacement, returning it as a full thickness graft. It is important to debride the recipient bed thoroughly, particularly removing any damaged fat to enhance revascularization of the restored part. When the amputated portion is not retained the defect may be treated conservatively with dressings, by the application of split, full thickness, or composite toe pulp grafts, or by the use of flaps. The indications for these various treatments are similar to those in adults; however, the greater regenerative potential in children dictates a greater dependence on conservative measures. In the case of failure of revascularization of the replaced avulsed segment it should be retained as a biological dressing until healing occurs underneath and the dry eschar separates (Figure 14.7.1D,E).

Fingertip injuries with an underlying distal phalanx fracture should be thoroughly washed under anaesthesia, prior to reduction of the fracture. These fractures are sufficiently stable following the soft tissue repair not to require further stabilization. Wiring may damage the epiphysis, and serve as a portal for infection in these open fractures. A mid shaft distal phalanx fracture is uncommon in children, as the points of weakness produces tuft or proximal physeal fractures. In the under 5s the commonest distal phalanx physeal fracture is a Salter–Harris type I pattern, eponymously described by Seymour. The child presents with avulsion of the nail plate from the nail fold. The injury appears innocuous but is an open fracture. Seymour fractures should not be treated conservatively as they may become infected leading to destruction of the physis, leading to growth disturbance. Seymour fractures are frequently missed until they present as a paronychial infection. A good lateral x-ray at the time of the original assessment is mandatory, but the only radiological clue may be a widening of the physeal line (Figure 14.7.1F,G).

Amputated digits occur infrequently in children. Unlike adults every attempt should be made to replant amputated parts irrespective of the level of the injury or the involvement of a single digit, within limits of technical ability. The outcome of replants in children is more favourable than in adults. With due care to the epiphyses, even growth of the replanted digit can be normal.

Tip amputations are treated depending on the degree, direction, and salvage of the loss. Complete tip amputations at the level of the proximal nail fold should be replanted if the part is salvaged. If replantation fails or should the part be not suitable or unavailable, the tip should be reconstructed making every attempt to maintain length. All the methods used in adults may be used. The results from many procedures is better in children due to greater digit flexibility, a lower tendency to joint contractures, better sensory restoration even in non innervated flaps or grafts, and better cortical re-orientation in neurotized switch flaps. One reconstructive technique that works particularly well in children when the amputated part includes the nail apparatus and revascularization is not possible, is to retain the nail and surrounding skin but discard the phalanx and pulp, replace the nail portion on the end of the finger and revascularize it with a palmar flap such as a cross finger flap (Figure 14.7.2).

Hand fractures are one of the most common presenting problems in children, occurring at a rate of 26.4 fractures per 10 000. Hand fractures form 25% of all childhood fractures, with the proximal phalanx of the border digits the most affected. One-third of paediatric hand fractures involve the physis, with 78% being Salter–Harris type II, 13% type III, and 7% type I. Dislocations are uncommon. Although most paediatric hand fractures can be treated conservatively, it is important not to completely depend on growth to correct all displacement.

The differences between adult and child hand fractures include rapidity of healing, pattern of fracture related to the mechanism and zones of weakness along the physis, tolerance of displacement, growth, and variation in the risk of stiffness.

Fracture healing in children occurs in about half the time of adults. This means shorter periods of immobilization but also that delayed presentation generally indicates closed reduction will no longer be possible. The mechanism of injury is likely to be a lower energy fracture and the fracture pattern reflects the greater deformability of the bone and thickness of the periosteum in children. The incidence of open fractures other than trapped finger injuries is markedly lower in children. Stiffness is less commonly a problem in children due not only to the reduced period of immobility but also the remarkable tolerance of the tissues.

The physis is the cartilage plate between the metaphysis and epiphysis responsible for longitudinal growth. It is found at the distal end of the metacarpals except the thumb metacarpal, which has its physis at the proximal end like the phalanges. The physis is the weakest link in the digit and hand. Within the physis the zone of chondrocyte hypertrophy (zone III) is the weakest and most likely to fracture in children giving Salter–Harris type I and II injuries. During adolescence, the physeal zones become less distinct leading to more Salter–Harris type III and IV fractures. The pattern of fracture is also influenced by the attachments of the ligaments and tendons. The collateral ligaments of the interphalangeal (IP) joints attach to the epiphysis and the metaphysis at the base of the phalanges, and this protects the physis form lateral forces. However, in the finger metacarpophalangeal (MCP) joints the collateral ligaments inserts only onto the epiphysis of the proximal phalanx, so lateral force produces a Salter–Harris type II or III fracture. The palmar plate inserts into the epiphysis so injury causes a Salter–Harris type III avulsion fracture of the epiphysis.

Physeal growth will correct some deformity in the dorsal and palmar planes but not in rotational or radial and ulnar planes. The degree of correction depends on the proximity of the injury to the physis (the closer the better), the degree of deformity, and the amount of growth potential remaining. Injury to the physis may lead to premature arrest of growth or growth deformity should the injury and growth arrest only involve a part of the physis. The Salter–Harris classification of physeal injuries predicts fracture stability and the potential for growth disturbance (see Chapter 14.2).

Salter–Harris type I injuries (see Figure 14.7.1F) with a transverse slip of the metaphysis from the epiphysis along the plane of the physis are commonest in the distal phalanx of young children with fingertip crush injuries. Reduction after wash out and simple immobilization may be all that is required. Replacement of the nail under the nail fold provides sufficient stabilization. Growth disturbance is unlikely.

Salter–Harris type II injuries with physeal separation and a fragment of metaphysis, is the commonest form of physeal hand injury. These frequently present at the bases of the proximal phalanges with bruising, pain, and deformity. These are generally easy to reduce and are stable after reduction. Reduction can be aided by the use of a pencil placed in the web space to provide a fulcrum on which to exert the reducing force or by flexing the MCP joinys to tighten the collateral ligaments and stabilize the proximal segment. Buddy splinting may be all the immobilization required. Growth disturbance is unusual (Figure 14.7.3A).

Salter–Harris type III injuries are physeal separation with a fracture fragment of the epiphysis. These are intra-articular and hence require careful reduction and frequently fixation for a short period, as they may be unstable. Fixation is usually by fine K-wires. These are more commonly seen at the distal phalanx in adolescents and present as mallet finger injuries, or less commonly at the middle phalanx as a central slip type injury causing boutonnière deformity, or of the proximal phalanx of the thumb presenting as a ‘bony game keeper’s thumb avulsion’.

Salter–Harris type IV injuries extend through the physis and are associated with a potential for growth disturbance. These are also intra-articular and careful reduction and fixation is required. Salter–Harris type V injuries are rare and are a crush injury of the physis. They are often not diagnosed until the growth arrest is noted.

What the Salter–Harris classification does not consider is the degree of displacement of the fracture fragments. Growth allows spontaneous correction of some displacement, see Box 14.7.1.

Paediatric hand fractures become increasingly common with adolescence, in association with increasing activity and skeletal maturity. The commonest fractures are fractures of the phalangeal shaft, particularly the proximal phalanx. As mentioned previously, minor angulation (up to 30 degrees up to 10 years of age, and less than 20 degrees in those older) in a palmar or dorsal plane will remodel; however, angulation in lateral planes or rotational deformity will not remodel and thus must be reduced and stabilized, if clinically indicated. Phalangeal fractures without gross displacement are frequently stable postreduction due to the thicker periosteum in children. In these cases 2–4 weeks of buddy strapping or splintage with the hand in an intrinsic plus position is sufficient. However, very displaced fractures indicating a greater degree of periosteal disruption will commonly require fixation. Fixation by closed reduction and fine percutaneous Kirschner wires is adequate (Figure 14.7.4). Additional support by buddy strapping will allow early mobilization. Wires are removed at 3 or 4 weeks, once clinical union is achieved. Wires that are left exposed through the skin can be removed in the outpatient clinic without anaesthesia; however, care must be taken during their tenure that the tips are well protected to prevent injury.

Intra-articular fractures must be carefully reduced and fixed to prevent long-term problems. These fractures are often condylar fractures of the head of the proximal phalanx. These are easily missed and can result in reduced flexion of the proximal interphalangeal (PIP) joint as the proximal fragment blocks the subcondylar recess. Closed reduction should be attempted to minimize the risk of avascular necrosis of the small fragments. Reduction must restore correct alignment of the articular surface and ensure the subcondylar recess is restored. Occasionally, these fractures are best reduced under direct vision. Accurate relatively stable fixation with minimal trauma to the tiny bony fragments is usually best achieved with small K-wires. With open reduction care must be taken not to devascularize the fragments by preserving any soft tissue attachments (Figure 14.7.5).

Fractures of the neck of the proximal or middle phalanges are often hardest to diagnose and extension of the head or even 180 degrees of rotation may not be appreciated. These fractures need to be reduced and K-wired. The technique involves inserting a wire longitudinally down the distal phalanx, then hyperextend the distal interphalangeal (DIP) joint and pick up the displaced head of the proximal phalanx, then reduce the fracture and pin to the shaft of the middle phalanx (Figure 14.7.6).

Metacarpal fractures are common in late adolescents. The mechanisms and patterns of injury are similar to those in adults. See Box 14.7.2 for acceptable metacarpal position.

If an unacceptable degree of angulation exists clinically and radiologically, then reduce the fracture using the Jahss manoeuvre. This consists of flexing the MCP joints and IP joints then pushing dorsally on the PIP joint, whilst pushing down on the metacarpal shaft. Once the fracture is reduced, stabilize it using K-wires or plaster of Paris. Wires are much more difficult to insert into the metacarpals of children due to the lack of metacarpal head collateral ligament recesses and hence the lack of ‘shoulders’ on which to aim the wires. Consequently there is a much greater risk in children of the wires impinging on the extensor tendons or the MCP joint. This is not too great a problem provided the MCP joint is kept in a flexed position and the wires removed within 3 weeks. As children will tolerate immobilization of their IP joints in a flexed position for 2–3 weeks, maintenance of the reduced metacarpal neck fracture is possible by bandaging the ulnar two digits in a fisted position. This maintains the fracture in a more stable position than gutter splinting. Three weeks is adequate immobilization before protected mobilization is commenced. Protection is provided either by splinting or by buddy strapping.

Metacarpal shaft fractures are treated as in adults, mainly needing reduction to correct any severe angulation and rotational deformity. Intra-medullary fixation techniques such as Bouquet wiring are generally not possible due to the narrowness of the canal. Metacarpal base fractures and carpometacarpal dislocations are uncommon in children, but when they do occur they require closed reduction and K-wire fixation.

Thumb metacarpal fractures are frequent and are usually found at the proximal metaphysis or physis (Figure 14.7.7). Epiphyseal fractures are usually Salter–Harris type II, with the small Thurston–Holland metaphyseal fragment usually found on the radial aspect. Reduction of these fractures is easy but they are often difficult to stabilize without using K-wires due to the displacing forces. These forces are the radial pull of the abductor pollicis longus on the proximal fragment and the ulnar deviating force of the adductor on the distal fragment.

Good results are almost inevitable in children’s fractures unless complicated by surgical intervention or infection. Avoidance of angulation, rotation, and intra-articular deformities leads to good results in paediatric hand fractures. Malunion is the commonest complication albeit uncommon. If detected before 2 weeks the malunion may still be amenable to closed manipulation. Beyond this period, open exposure and careful unpicking of the malunion should be possible up to the 6- or 8-week stage. Subsequently they should be treated as in adults with opening or closing wedge osteotomies or rotational osteotomies either at the site or distant to the site of the malunion. Care must be taken to avoid damage to any physis. In cases of intra-articular malunion all attempts at intra-articular realignment should be made. Failing that, a pseudarthrosis usually gives adequate function. It is exceptional to consider procedures such as arthrodeses, or arthroplasty.

PIP joint dislocations are usually dorsal. Reduction is usually easily achieved and following this the PIP joint is usually stable, requiring only buddy strapping or an extension-blocking splint for 2–4 weeks. Rarely collateral ligament ruptures result in gross lateral instability and require repair. Open reduction may be required in cases of irreducible dislocations due to interposition of soft tissue such as an articular flap or the button holing of the proximal phalanx head between the palmar plate and the flexor tendon.

MCP joint dislocations are rare other than in the thumb. The index fingers are the next most commonly affected, and in this case are often irreducible due to the button holing of the metacarpal head between the flexor tendons and the lumbrical. Open reduction can be performed from either a palmar or dorsal approach, though one must be wary of the displaced digital nerves when approaching from the palmar aspect.

Thumb MCP joint dislocations are less common in children than adults due to the relative strengths of the soft tissues to the epiphysis. When they do occur however the pattern is similar to adults. Both simple and complex dislocations occur. Simple dislocations are amenable to closed reduction by hyperextension of the MCP joint and then with pressure on the base of the dorsum of the proximal phalanx a longitudinal traction and flexion force is gently applied. Complex dislocations require open reduction to free the palmar plate, or the entrapment of the head of the metacarpal between the volar plate and the flexor tendons. The x-ray signs of the proximal phalanx lying almost parallel in line with the metacarpal (as opposed to lying angulated in simple dislocations) or the presence of a widened joint space or with the sesamoid bone lying interposed can predict complex dislocations.

These injuries become more frequent with increasing age. The mechanism of these injuries differs from those in adults—most are clean, tidy sharp injuries caused by glass. As the principles of the treatment, particularly the surgical technique of these, are similar to those in adults already presented in previous chapters, this section will concentrate on the differences and special features of these injuries in children.

The major difference is the growth potential and the reduced cooperation with rehabilitation. Growth can be inhibited by lack of movement and scar, and to a larger extent by denervation. Postoperative care is affected by the age and cooperation of the child and rehabilitation is generally limited. However, tendon healing occurs faster and with fewer adhesions than in adults. Hence the results are frequently better, and the complications fewer. The operative techniques and principles are the same, keeping in mind the increased fragility of the structures such as the pulleys. Children’s flexor tendon repairs require special care in their assessment and examination, postoperative care and rehabilitation, and operative indications when complications arise.

Due to the lack of cooperation and compromised examination, all children with deep lacerations of the upper limb should have a general anaesthetic for adequate exploration and repair of the wound. Some preoperative prediction of the injuries can be made by observant examination skills including specialist examination techniques, such as the tactile adherence and immersion test for sensory assessment, and tenodesis and forearm squeezing techniques for assessment of musculotendinous continuity. This will permit discussion with the parents and theatre staff about the likely operative procedure and timing.

Children’s flexor tendon injuries should be explored as soon as possible, though a delay of a few days is unlikely to affect the outcome. The tendon should be repaired primarily. The mechanism of injury is usually a fall onto glass or whilst clutching a glass, meaning that more frequently than in adults the distal tendon end is found at the level of the laceration making the exposure and repair easier. The smaller tendon structure may prevent the use of a multiple strand core suture tendon repair technique, though this may still be possible if a smaller gauge of suture such as 4/0 is used. The tendon repair strength may be less important in children if immobilization rather than active motion techniques are used for postoperative rehabilitation. Immobilization following repair is the usual postoperative regimen due to the lack of cooperation with exercises and because although children do develop tendon adhesions, once formed the adhesions seem to be more responsive to manipulation and therapy. There is a tendency for long-term absorbable sutures such as PDS to be used rather than non-absorbable sutures, though there is no scientific evidence to support or refute this practise.

In zone 1 injuries, care must be taken not to injure the distal phalanx physis when reinserting the tendon. In zone 2 injuries every attempt should be made to repair both flexor tendons. In situations of delayed repair or untidy injuries requiring debridement of the tendon endsn significant tendon shortening can occur. This would preclude primary tendon repair in adults so as to prevent the quadriga effect, in which one tendon is out of synchronization with the others leading to reduced movement. However, shortened tendon repair is possible in children, as musculotendinous lengthening and readjustment of tension occurs more readily and is far more forgiving. Flexor sheath closure and pulley preservation or reconstruction, are as important as in adults.

Postoperative rehabilitation differs depending on the age and understanding of the child and their parents. Immobilization for 3–4 weeks is as effective in the final outcome. This is probably because complete immobilization is impossible and these children move within the confines of their protective splint or bandage, thereby performing their own protected active mobilization programme. Results deteriorate if they are immobilized for longer than 4 weeks. Children are more likely to spontaneously use their hands once their splints are removed and require less directed therapy to achieve function. Botulinum toxin can be used to weaken the affected muscles so as to reduce the risk of tendon rupture, though rupture can still occur with unintended extension.

The results of flexor tendon repairs in children are generally better than those achieved in adults. However, tendon ruptures and adhesions preventing movement do occur. Tendon rerupture is difficult to assess in children. Assessment is dependent on history, palpation of the tendon, assessment of active and tenodesis movement, and ultrasound examination. An acute rerupture detected early may be amenable to direct rerepair. Frequently the tendon rupture is not detected until a later stage (beyond 2 months) and direct repair is not possible. The situation is then similar to delayed detection of a tendon injury.

The use of immediate or staged tendon grafting techniques is controversial in children. Some believe tendon grafting procedures should only be performed once the child is old enough to participate in rehabilitation programmes. There is little evidence on this subject however, and it is reasonable to perform the tendon graft regardless of age, in order to obtain better function. Children develop hand use patterns during early years, and further digital growth and development are dependent on function, so all attempts should be made for reconstruction of normal anatomy and function in children. Alternatives to tendon repair such as tenodesis or arthrodesis of the DIP joint are contraindicated due to the potential to interfere with growth.

Tendon adhesions are uncommon in children. Indications for tenolysis are similar to adults though the timing of the operation is disputed. Tenolysis is recommended when the child is old enough to understand and participate in the rehabilitation programme.

Closed extensor tendon injuries are rare in children. When they do occur it is essential to exclude epiphyseal fractures, particularly in the closed mallet finger. These are usually Salter–Harris type I in younger children and type III in older children, the latter mimicking the bony avulsion injury seen in adults. Treatment of these is identical to adults, though the challenges involved in maintaining a splint on the child may increase the number that are pinned in extension rather than just splinted. The period of splintage can be reduced by 2 weeks in children.

Delay in the diagnosis of extensor tendon injuries is common in children. Despite the delay the treatment is the same and good results can be obtained in mallet and boutonniere injuries with splintage. Splinting periods in the treatment of delayed extensor tendon injuries in zones 1–5 are 2–4 weeks greater than when treating the acute injury.

Open extensor tendon injuries are more common, usually associated with a crush injury. When there is associated nail bed or epiphyseal injury, operative treatment is indicated. When the injury is a clean tidy laceration over the middle phalanx or the IP joints (extensor tendon zones 1–4), then tendon approximation is possible solely by splinting the finger in extension for 4–6 weeks. The extensor tendon does not retract like the flexor due to the anatomical structure of the extensor tendon at this level. This feature allows direct repair even in cases of delayed detection of extensor tendon division. Where direct repair is not possible all methods of adult reconstruction can be used in the child, with a preference for those that reconstruct the normal anatomy and interfere least with growth and development.

Rehabilitation of extensor tendon repairs depends on the level of the repair. Digital injuries should be splinted for 4 weeks, whereas hand and forearm injuries should be mobilized earlier. Where pins or K-wires have been used for internal splinting, these are carefully protected to prevent them being pulled out or causing injury, early mobilization in a removable splint can be used in cooperative children. Once the splint is removed, the children are allowed to use their hand normally.

Extensor tendon adhesions causing poor movement should be tenolysed following a lengthy trial of mobilization. The results of extensor tendon surgery in children are poorly reported but generally believed to be better than those in adults. Some extensor lag or loss of flexion may occur in 22%.

A high index of suspicion of nerve injury should exist when assessing hand lacerations. Examination of nerve injuries in children is even harder than tendon injuries. If any doubt exists, lacerations should be explored under general anaesthesia. The operative techniques are identical to those previously described for adults. The peripheral nerves are more mobile in children and so less tension is present at the repair site. Consequently, less post operative immobilization is required. Two weeks should be sufficient, if there are no other injuries. The results of nerve repair are much better in children, and this is rewarding surgery. Better results are attributed to better regenerative ability of the nervous system, better neural ingrowth from surrounding areas, and better central cortical reorientation. Children’s superior cerebral ability to develop and adapt probably accounts for a large proponent of their better outcomes. Nerve injuries complicating fractures or tendon lacerations are associated with worse outcomes of all the involved injuries. Tendon transfers of functioning muscles following identical principles used in adult transfers can treat failure of motor recovery. During neural recovery the child will need protection from injuring the insensate portion of the hand.

Hand and upper limb burns are amongst the commonest injuries presenting in children. The mechanism is usually a scald caused by the child pulling a cup of hot liquid off the table. Almost all scald hand burns heal spontaneously, requiring little more than assessment, analgesia, reassurance, dressings, and follow-up. However, not all burns are that simple. The outcome and management depend on the depth and size of the burn. Assessment of burns is based on history and examination. The size of the burn is measured and recorded as a percentage of body surface area and the depth is assessed using the same principles described in Chapter 12.24).

Remove the heat source and cool the burn with running water for 20min. Resuscitation should be given in accordance with Advanced Paediatric Life Support (APLS^®) protocols.

Blisters should be debrided as they contain eiconasoids and prostaglandins detrimental to healing and which deepen the burn. Once debrided, desiccation and infection must be avoided, as these will also deepen the burn. Dressings such as paraffin gauze and absorbent gauze are useful in the first few days when the burns are quite productive of ooze. Dressings should be made as light as possible to allow some movement. Once the ooze has diminished, the burn can be dressed with a retention dressing such as Hypafix, Mefix, or Fixomull, adhered directly onto the burn. This dressing can be washed, allows almost normal mobility, and is easily removed, as the adhesive is oil soluble.

The general rule is that if burns heal within 10–14 days then hypertrophic scarring is unlikely. However, deeper burns that remain unhealed at 14 days have a high risk of developing contractures and hypertrophic scarring. If the burn is obviously deep or fails to heal within 2 weeks then the burn should be debrided and skin grafted. Debridement should aim to remove all dead tissue but preserve as much dermis as possible. Dermis preservation or reconstruction is the key factor in outcome in terms of scarring and contracture.

Severe burns should be admitted for analgesia, splinting into a functional position, assessment, elevation to reduce oedema, and preparation for surgery.

Children should be followed as they grow, as scars that initially were non-contracting may become tight and cause functionally limiting contractures. These may require surgical revision by excision and grafting, local flaps, or Z-plasties.

Dogs and cats cause most bites in children. The principles of assessment of underlying structures, exploration if indicated coupled with good surgical excision, and primary closure is as true in children as in adults. The infecting organism is usually Pasturella multocida or mixed organisms, sensitive to penicillin or co-amoxiclav.

Children’s hand injuries are extremely common but most are easily primarily treated with excellent outcomes to be expected. The greatest error is in underestimating the degree of injury. Failure to recognize and treat the injury or failure of treatment can lead to devastating loss of function and growth, which may not be immediately apparent.