Approach to Slipped Capital Femoral Epiphysis
– there is a narrow window when this happens – just in the growth spurt area (11-13 in girls, 13-15 in boys)
– may be related to endocrine abnormalities: hypothyroid, hypopituitarism, hypogonadism, increased growth hormone; Also seen in FAT kids
– The key physical finding is an obligatory external rotation of the hip when flexing
Defined based on if the kid can walk on it or not (stable or unstable); chronic slips tend to be stable; acute slips tend to be unstable. Note that the stable ones can acutely become UNstable – therefore, if the kid arrives in emerg, walking, with a stable slip, he gets immediate BEDREST and an OR as soon as can be arranged. He DOES NOT GET DISCHARGED HOME ON CRUTCHES.
Southwickï¿½s Femoral head – shaft angle: measured on the frog lateral. Should be 10o; increased in slips
Kleinï¿½s line – a line drawn along the superior border of the neck should pass through part of the epiphysis in the normal hip on an AP pelvis. In slips it misses the epiphysis superiorly. (also called Trethovan sign)
Look for increased metaphyseal density on the AP (superimposition of the head behind the metaphysis)
– single pin fixation
– kids with endocrine abnormlaties get prophylactic pinning of the other side; this is the only indication for prophylaxis
– the hugely displace slips should probably have a bone scan to document avascularity of the head, then a GENTLE closed reduction maneuver (according to Morrissey) prior to fixation
Beware AVN and chondrolysis – these are the two main complications; they generally do not occur in untreated slips.
What happens when their head collapses from AVN?
– rule out sepsis (clinically, bloodwork)
– then, assess where the screw is – Is it in, or nearing the joint surface? then you need to consider taking it out.
– then decide, What about the physis – has it closed yet? Get a CT scan to see if the physis has fused yet. If it has, you are safe to take the screw out. If it has not fused, you can do one of two things:
1. revise the screw to a shorter screw and hope that the thing will heal before the progressive collapse reveals the screw tip to the joint.
2. do an open bone peg epiphyseodesis.
What about ruling out ï¿½endocrine abnormalitiesï¿½?
– the obese boys who get this when theyï¿½re 14 are probably okay.
– but any boy