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5 Paediatrics
5.5 Management of the atraumatic limping child
Monica Lalanda, Neil Featherstone.
December 2001
Objective
The attendance to A&E of limping children without a clear history of trauma is very common and it always constitutes a diagnostic challenge.
Transient synovitis (TS) is the commonest cause but this diagnosis should only be made after exclusion of more serious disorders
A systematic approach is essential and therefore, we need a protocol that will screen for TS yet identify significant pathology.
CLINICAL CONDITION
Table 1. Differential diagnosis of acute limp by age |
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Toddler (1-3 years) |
Child (4-10 years) |
Adolescent (11-16 years) |
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DDH |
Transient synovitis |
SUFE |
Toddler’s fracture |
Perthe’s disease |
Avascular necrosis femoral head |
Leg-length discrepancy |
Juvenile RA |
Gonoccocal septicaemia |
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At all ages: |
Septic arthritis, osteomyelitis, cellulitis, stress fractures, neoplasms and neurological causes |
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More unusual causes for a limp: non accidental injuries,sickle cell crisis, referred pain (testicles, appendicitis), metabolic disease, Kawasaky disease and pyogenic sacroilitis.
INVESTIGATIONS
1. On arrival all children with an unexplained limp or painful leg need a full history taken, with special interest on previous similar episodes and recent minor infections.
In most cases of TS the parents will mention that the child went to bed as normal and woke up with a limp.
2. It is essential to examine the child fully and not only the leg. Look for abdominal masses ( neoplasias in children can present with a simple limp), examine the testicles and perform an ENT exam. Look for bruises in unusual areas, remember the possibility of a non accidental injury.
Examine the whole affected leg. Keep in mind that a painful knee can just be a refered pain from the hip. Assess the three main joints for passive and whenever possible active movements. Effusion in the hip will make internal rotation and abduction particularly painful .
Look for bony tenderness of the tibia and fibula. If the child is crying at the time it will be useful to distract him/her and reassess. It is not uncommon for toddlers to suffer a tibial # with relatively minor trauma. If there is obvious tenderness and the child is otherwise well, treat is as a toddler # with a POP and bring back for re X ray in 10 days.
Feel the skin. Warm areas could mean infection and sometimes fractures
3. Ask for a temperature, it is significant if over 37.5.
4. Organise an USS of the hip to find out if there is an effusion. This is first line investigation for children younger that 8 years old. Older children will require a pelvis X-ray to exclude more common pathology at this stage: Slipped Upper Femoral Epiphysis , Perthe’s disease. If this x-ray is normal then it is appropriate to request an USS.
5. FBC/PV/CRP need to be done in all children younger than 8 and in those older than 8 with a normal x-ray.
It is essential that all the non traumatic limping children have all the above mentioned investigations done as only the combination of all these predicting factors will be sensitive enough to exclude a very serious condition such as septic arthritis.
Predicting factors of septic arthritis : Effusion
Fever
Abnormally high PV or CRP
High WCC (this may take more time to appear)
Table 2. Predictive probability of septic arthritis |
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Number of predictors |
Predictive value (%) |
0 |
0.2 |
1 |
3 |
2 |
40 |
3 |
93.1 |
4 |
99.6 |
DIAGNOSIS AND TREATMENT
For children < 8 years old
1. Effusion in USS + temp>37.5 +abnormal bloods= immediate referral for aspiration of effusion. These children are very likely to have septic arthritis
2. Effusion on USS + temp<37.5 + normal bloods = Typical transient synovitis. These children can go home with advice to rest, regular paracetamol and an appointment to return in 10 days to A&E returns clinic.
Transient synovitis is an acute, self-limiting inflammation of the synovial lining of the hip. The cause is unknown: it has been postulated to be due to viral, traumatic and allergic causes
When there is no effusion and the bloods are abnormal, x-ray may be appropriate to exclude osteomyelitis.
For children > 8 years old
SUFE needs immediate referral to the orthopaedic team. Delay in treatment can cause long term damage to this child’s hip. Perthes disease can wait to next fracture clinic.
For decisions on referals and treatment follow the algorythm.
Clinical algorithm
Unfortunately there are no national guidelines for the management of the limping child. I have devised this algorithm based on the prospective and retrospective studies on recent articles mentioned as references. I have taken into account as well what is happening in several centres of excellence like the Sheffield Children Hospital, Alder Hey and the Royal Hospital for sick children in Edinburgh.
An algorithm for out of hours management is included.