PAGE 26 the knee the medial and lateral femoro-tibial joints are only

A

B

2cm apart , in the forearm the proximal and distal radio-ulnar joints are 30cm apart , but function as a single unit . The massive separation between the condyles means that angulation in the shaft of the bones is poorly tolerated . A 10 ° radial malunion causes a loss of 20 ° of forearm rotation .

There are many activities done in full supination , such as carrying a dinner plate , getting changed or bottom wiping . And there are activities requiring full pronation , such as typing , eating with a knife and fork , or spin bowling . This means that , if a five-year-old patient has a 20 ° dorsally angulated malunion of the distal radius , an important part of the informed consent to that treatment is to warn the parents that their child will have an ugly-looking wrist and have difficulty with their school work and activities of daily living for at least 2-3 years , with the possibility that they will never fully recover . Their options for activities like sport and music will be limited in the medium to long term .

As with many medical treatments , early active intervention may be beneficial to prevent long-term disability , and given the choice , many parents will opt for internal fixation of a difficult-to-reduce fracture rather than dealing with years of disability and potential reconstructive surgery , which is less effective .

C

Figure 9 . This 15- year-old boy ( A-C ) has almost fused growth plates , so the classic skier ’ s thumb is a Salter III fracture . No longitudinal growth remains , so typical screw fixation is ideal . In a younger patient ( D ), the screw must avoid penetrating the growth plate .

D

Figure 11 . This 13-year-old boy was snowboarding . His right is a torus ( buckle ) fracture amenable to manipulation and short arm ( below-elbow ) cast . The left , although expertly reduced by the snowfields doctor , is oblique and will redisplace . Internal fixation gives stable anatomic reduction , with no need for a cast . Although the worse injury , the left is quicker to rehabilitate for activities of daily living — in particular , the ability to wipe his own bottom . Both patient and parents were delighted with this .

Nail-bed injuries

This common injury results from fingers getting caught in a slammed door ( see figure 12 ). The hinge side is always worse because the fulcrum and the load are close together .

The fingertips are the most richly innervated parts of the hand , and the nail bed is positioned between the hard nail plate and the bone deep to it . Anyone who has ever had a subungual haematoma knows that it is impossible to sleep until it has been drained . Minor subungual haematomas respond to drainage . The traditional method of a hot paperclip works if you have a spirit lamp — for example , to warm the mirror in ENT examination — or a gas stove . In the author ’ s experience , a cigarette lighter will burn your fingers before it heats the paperclip to keratin-melting temperature . In a camping situation , or a small general practice treatment room , a fine needle , like a 25 or 27 gauge , can be slowly pushed under the nail from the distal hyponychium to drain the haematoma . This is less painful than it looks . In an operating theatre , where naked flames are prohibited , a small highspeed drill does the job superbly .

A more major subungual haematoma , and a higher-energy injury , is

often associated with a nail-bed laceration and an underlying fracture ( see figure 13 ). These require formal removal of the nail plate and suturing of the nail bed under magnification with a conjunctival spatula needle suture , typically 8-0 Vicryl in a small child , 7-0 Vicryl in a teenager .

A particularly dangerous fracture in the nearly skeletally mature is the Seymour fracture . The growth plate is almost closed , and typically in a 14-16-year-old boy , the enthusiasm for contact sports is increasing . A direct blow , such as being tackled with the football in the hand , and landing on the ground fingertip first , causes what is often a Salter I fracture through the growth plate . But the

Figure 10 . Netball is the biggest breaker of women ’ s and girls ’ fingers . This 13-year-old has impressive acute bruising at 24 hours despite only a tiny chip fracture of the volar lip of the middle phalangeal epiphysis . This is a volarplate avulsion fracture , technically a Salter III but with minimal articular damage and at the end of growth . Buddy taping , or a dorsal block splint if very ligamentously lax , will prevent dislocation .

entire nail pops out above the dorsal skin , so a view from the proximal end would be looking at the torn edge of the nail bed and then the distal phalanx . This open fracture will become infected unless it is carefully debrided and then surgically reduced . Because of the circumstances of the injury , it is not uncommon to find blades of grass between the two ends of the bone .

Foreign bodies

These include wood splinters from

play equipment or climbing fences and trees , and glass from either the child ’ s own glass breaking or from the discarded beer bottle in the park . Steel and aluminium cans and plastic bottles have limited the injuries from broken glass .

Wood splinters that come off a dilapidated fence are often quite friable when removed with forceps , and fragments commonly remain behind . Seeing the base of the wound is crucial , and preoperative ultrasound

Figure 13 . Major subungual haematoma with underlying fracture .

may identify more than one foreign body .

Glass will always show on X-ray , provided it is not obscured by the bone . Multiple projections may be needed , and if the fragments are small , asking for a mammogram film of the finger can show tiny fragments . CT scan will show deep fragments that are close to the bone , for example , in the volar recess of a joint . Ultrasound is ideal for radiolucent wood or plastic fragments .

Figure 12 . Injury in a five-year-old girl who caught her finger in a bedroom folding door , avulsing the pulp down to the bone . Nail-bed repair prevents functional and cosmetic deformity . Although the injury is one fingertip , the whole hand was unnecessarily imaged . A referral specifying a focus on the relevant anatomy will give better diagnostic yield .

PREVENTION

All public pools have a ‘ no glass ’ rule . Advise your patients to extend this to any paved / tiled area of their home and to use polycarbonate glasses and melamine plates . These are ideal for outdoor dining , bounce when dropped and will not shatter in the hand if a child falls on them .

Domestic violence

Unfortunately , a high index of suspicion is needed as not all injuries