BMJ 2010: 341: 409 – 64 (28th August)

The review article this week is on evaluating children with acute limps.  As far as history-taking goes, I already know to ask about fever/systemic illness, duration, pain, and history of injury (though it’s important not to put too much weight on the last – apparently children can associate a symptom with an unrelated injury and, for example, often children with Perthe’s disease will describe an initial injury).  For limps in young children, bear in mind that the birth/developmental history can also be important in providing clues to possible DDH or cerebral palsy. Ask about pain/stiffness in other joints.  And do be on the lookout for any reason to suspect NAI.

Here’s what I need to know about examination:

Look

  • Check temperature (also look for tachycardia and general signs of unwellness)
  • Check the spine (tufts of hair or sacral pit that may indicate dysraphism; any curvature; curve of flexed spine from behind & from side when child touches toes).  Although it’s technically under ‘feel’, this is a good opportunity to check for focal tenderness as well.
  • Pelvis level?  Legs of equal length?
  • Any obvious joint deformity or swelling?
  • Wasting/hypertrophy of muscles?
  • Gait (I know this is supposed to be under ‘move’, but it’s easier to check it here).  Normal walking, on tiptoes, and on heels.  I have no idea what the latter two are for, but it’ll give me something to report in a referral letter, I suppose.
  • Trendelenburg test (getting child to stand on one leg & looking for downward tilt of pelvis)
  • And, because the child isn’t going to be put on the examination table until the end of this bit, I’m going to repeat the reminder here to check that the legs are of equal length.

Feel

  • Check spine, pelvis, and lower limbs for tenderness (note the need to check the tibia in young children for tenderness possibly indicating toddler’s fracture – see below)
  • Check joints for warmth
  • Check knees for effusion

Move

  • ROM of each joint.  Check for crepitus in the knees during movement, and ask about pain on movement.
  • Internal rotation of hip in 90 degrees of flexion – same ROM on both side? (This is particularly important – restriction of internal rotation is the most sensitive sign of hip pathology in children.  In case you’re curious, loss of abduction is the second most sensitive sign, but can be difficult for even experts to assess as children can tilt their pelvis to make it look as though their hip is abducting.

Abdomen and testicles: Pathology in either of these can present as a limp, so, after the orthopaedic examination, check both.

What are the red flags? I knew about fever/systemic illness and about inability to WB, but it turns out age is a red flag as well – transient synovitis is rare in the under-3s and a child in this age group with a limp should be referred urgently for expert assessment.  Likewise, a limping child over 9 with pain or restricted hip movement should be referred urgently.

Now, useful points to remember about various diagnoses:

Toddler’s fracture: I’d never heard of this, but it’s an undisplaced spiral fracture of the tibia in preschool children, which may occur when the leg is twisted in an unwitnessed fall and is difficult to diagnose; history is often vague, there isn’t much in the way of signs, and some of them don’t even have the grace to show up on initial X-rays, the sneaky bastards.  Treatment is with immobilisation and expectant management.  Bone scans may be needed if X-rays are negative.

Transient synovitis: Purely out of interest, the evidence for the usual “it’s a virus” explanation is in fact pretty weak, so we should probably stop using it.  More importantly, how should patients with a working diagnosis of transient synovitis be followed up?  Well, first off, bear in mind that this is going to be the 3 – 9-year-old group (younger get urgent referral anyway; older and you’re suspecting SUFE), if afebrile and mobile and if symptoms present for less than 48 hours.  48 hours is the magic number for review.  After 48 hours you are expecting some improvement.  So, if the duration is less than 48 hours you tell parents to try getting the child to rest (lots of luck if they’re anything like my children, but we’re talking about the advice we hand out here) and to seek advice if symptoms worsen, if the child becomes feverish or systemically unwell, or if there is no improvement in – yup, you got it – 48 hours.  The next checkpoint is one week, by which time you would expect complete resolution of symptoms.  So (as long as things aren’t actually worsening, which is an indication for immediately starting the ball rolling on investigations), if you don’t get some improvement by 48 hours and complete improvement by one week, that’s when you get the investigations in motion.

DDH: I just put this in so that I could remind myself of what the acronym stood for, having gone to medical school in the days when it was still CDH (congenital dislocation of the hip).  DDH stands for ‘developmental dysplasia of the hip’.

SUFE: Remember that this can present with knee pain, so referred pain from SUFE is an important differential diagnosis of knee pain in this age group.  DON’T forget to ask for lateral views on the X-ray.  And a slightly younger child (say, around 8) may sneak into the risk group through other risk factors – obesity, history of endocrinopathy, or radiotherapy.

Right.  That’s it for that article.  Other tidbits for the week:

Women who’ve miscarried may wonder how soon they can, or should, try again.  One group of researchers, published in this issue, think the answer should be ‘soon’, as they found that conception within six months of a miscarriage was associated with a better outcome than conception between six and twelve months later.  However, seems to me there’s a pretty obvious flaw in that which, as far as I can see, they haven’t allowed for – the possibility that there’s an overlap in factors causing problems with carrying a pregnancy and factors causing problems with conceiving one, which would mean that the association wasn’t due to this being the best time to conceive given the choice but due to the fact that the women who could conceive again that quickly were more likely to carry a pregnancy to term.

(Edited to add: I checked the full paper on line, and the authors do mention this possibility.  They aren’t specifically advising women to try earlier, just pointing out that they don’t have to make a point of waiting six months as the WHO recommended.)

Likewise, patients on medication for psychotic illnesses may want to know when they can stop.  A randomised placebo-controlled trial reported in this issue found that patients with a first episode of psychosis, well controlled on quetiapine a year later and doing generally fine, were still substantially more likely to relapse if they stopped quetiapine than if they continued (associated risk a whopping 32.6% – almost one in three).  Although it is worth pointing out that this study was funded by AstraZeneca, so the possibility that they’ve sneaked a bias in there somewhere does need to be considered.

And a couple of useful tidbits from Short Cuts.  When I did my stint at a hospice, it was common to have to explain to patients that referral there did not necessarily mean death was imminent – on the contrary, patients would often be referred to us early in the course of an eventually terminal illness to discuss symptom control and possible respite care.  It seems we should be doing this even more.  Starting palliative care as soon as patients were diagnosed with metastatic lung cancer seemed to give patients a much better quality of life and fewer symptoms of anxiety and depression.

And fibromyalgia is always difficult for patients and doctors to deal with, but it seems Tai Chi may help.  More so than education plus stretching, anyway.

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About Dr Sarah

I'm a GP with a husband and two young children.
This entry was posted in BMJ, Orthopaedics, Paediatrics, Pregnancy and Childbirth, Psychiatry. Bookmark the permalink.

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