injury is lack of sweating because the sudomotor function of nerves travels

with the sensory branches . One side of the finger feels normal to your ungloved finger ; the other feels warm , dry and smooth .

Observing the child with their toys or utensils may also provide a good idea of global sensory function . It is very difficult to pick up a small object , such as a spoon with numb fingers .

Vascularity

Some vasospastic conditions , such as Raynaud ’ s disease , may present in children . And while arterial lacerations are rare , the parents can often describe the spray / splatter pattern of the cut artery . Children generally have superb collateral circulation , so it is unlikely that a single arterial injury would cause ischaemia of the finger . However , the artery lies posterior to the nerve , so the description of an arterial spurter almost certainly indicates a nerve laceration and should be referred appropriately .

Amputation

These are fortunately rare in children , but the author has seen cases where an older sibling has injured a younger with scissors , secateurs or an axe “ just to see what would happen ”.

In the event of traumatic amputation , dress the hand with a moist dressing . Rinse the amputated part / s ( normal saline is ideal , but tap water is readily available ), wrap in moist gauze and place in a plastic ziplock or tied bag . ^1-3 This can be put in the fridge , which is at an ideal temperature of 4 ° C , until the patient is ready for transport to the hospital . Pinning a note on the bed sheets that says “ take fingers ” is sensible , as the author has experienced cases where the fingers were forgotten .

For transport , the plastic bag can be placed in another plastic bag ( or a plastic container or bucket ) containing a mixture of water and ice . It is important not to use plain ice , as the domestic freezer at -18 ° C , or the hospital freezer at -40 ° C or -80 ° C , will rapidly cause frostbite .

Notifying the receiving hospital is of vital importance , preferably speaking directly to the hand surgery registrar or consultant on call so the case does not appear as a surprise . This also provides the opportunity to assess whether the institution you are sending them to is suitable . This avoids delays and may prevent loss of a digit .

While the lay press is very positive about replantation surgery , it is never as good as the original . It is perhaps the operation with the largest disparity

between the opinion of the surgeon and the patient — because from the surgeon ’ s viewpoint , they started with an amputation and ended up with something better , while from the patient ’ s viewpoint , they started with a normal hand and now have something worse .

Previous generations of surgeons saw many finger amputations in toddlers injured from exercise bicycles that had an unguarded chain and sprocket , but these are now less common as guards are compulsory on all exercise bicycles . Regular bicycles still cause injury .

Farm implements are particularly dangerous , as are power tools ( see figure 6 ) and kitchen implements ,

Figure 5 . The pen tip points to the wound , which was ‘ explored ’ and sutured . Persistent pain and a high index of suspicion for retained foreign bodies revealed a pile of glass fragments .

like stick blenders . Do not leave the latter two plugged in and unattended .

Tendons

In the author ’ s experience , cut tendon are missed more commonly in children than in adults on initial GP or ED examination . This is not so much a lack of competence but a lack of adequate equipment and anaesthesia .

TENDON EXAMINATION

The only way to be certain that tendons are intact is to look at them and pull on them , examining them over the full length , which may be at risk from the wound sustained .

In the case of the knife cut at the level of the proximal interphalangeal ( PIP ) joint flexion crease , if this was cut in flexion — for example , gripping a knife or sheet metal — the level of the tendon cut can actually be at the DIP joint .

This is particularly relevant in Adelaide , where a shortage of wood and a surfeit of termites led to the popularity of sheet metal fences . Children would often kick a football into the neighbour ’ s yard and then climb over the fence to retrieve the

ball . All going well , this worked , but a sudden slip would result in increased pressure on all eight fingers , giving Adelaide the world ’ s highest incidence of eight-finger tendon lacerations . ⁴ Ridge capping of steel fences is now compulsory .

The same injury can occur from carrying a piece of sheet metal or moving steel bookcases , filing cabinets or panes of glass .

The clinical examination of the suspected tendon injury is to check that each tendon is working , the

mass action profundus by flexing the distal joint and the independent superficialis by individually flexing the PIP joints . Around 15 % of the population do not have a superficial tendon to the little finger — usually bilaterally but not always . ⁵ Another good test of the superficialis function is to flex the PIP joint while hyperextending the DIP joint in the ligamentously lax because most children can hyperextend their DIP joints . The easiest way to examine is to demonstrate the movement and ask the child to copy you .

Bones

Long bones start forming early in embryonic life , with the clavicle at

four weeks ’ gestation . Metacarpals and phalanges are present at birth , as are the radius and ulna , but the carpal bones are cartilage , gradually ossifying about one bone per year . Children ’ s bones are far more fibrous than adults , with flexible cartilage components and very thick periosteum that has the texture of tyre rubber . It is extremely difficult to break the bones of babies and young children , which bend rather than break . As the bones become proportionally longer and ossify to

a greater degree , they become more susceptible to fracturing . In the first decade of life , the bones are almost always weaker than the ligaments , which are dense collagen , so a severe enough impact will cause a fracture rather than a dislocation .

Many bones — including the radius , ulna , metacarpals and phalanges — have growth plates ( physes ). The cartilaginous epiphysis ossifies separately from the diaphysis of the bone , and the part responsible for the lion ’ s share of longitudinal growth is a single cell layer on the side of the epiphysis , which points towards the diaphysis .

Evolution usually protects this area . As the cartilage cells bud off ,

Figure 6 . Power tools are always risky without skill , experience and PPE . This six-yearold girl has a whipper snipper laceration , with a compound fracture . Surprisingly , the growth plate did not fuse prematurely .

they die and undergo gradual ossification . Thus , the zone of cartilage calcification is the weak link in the system , through which fractures commonly occur . Epiphyseal fractures are categorised using the system described by Robert Salter , a Canadian paediatric orthopaedic surgeon ( see table 1 ).

Salter III and IV fractures require anatomical reduction , which generally means pinning or screwing . Be suspicious of a Salter V fracture after a high-energy injury , such as a

motorbike , horse or snowboard fall . Serial X-rays can detect cross union early , allowing the possibility of surgery to prevent progressive deformity . Generally , for the distal radius or ulna , an X-ray three months after the initial injury should provide information about normal growth or any abnormality .

SPECIFIC INJURIES

Forearm / distal radial fractures

IN the adult population , these are bimodal , occurring with a peak at age 19 in males and 73 in females in the author ’ s practice . In children , there is no specific age / sex incidence difference until the teenage years when