Relationship between ligamentous laxity and the site of upper extremity fractures in children: Extension supracondylar fracture versus distal forearmfracture
Se. Nork et al., Relationship between ligamentous laxity and the site of upper extremity fractures in children: Extension supracondylar fracture versus distal forearmfracture, J PED ORT B, 8(2), 1999, pp. 90-92
Eighty children who had fallen on an outstretched hand and sustained either
a displaced supracondylar fracture (group 1) or a displaced distal forearm
fracture (group 2) were prospectively studied. Ligamentous laxity in these
80 patients was determined by four methods: (a) contralateral elbow hypere
xtension, (b) knee hyperextension, (c) the ability to touch the thumb to th
e ipsilateral forearm, and (d) the ability to extend the thumb past the uln
ar border of the clenched fist. Elbow hyperextension averaged 10.5 degrees
in group 1 and 4.4 degrees in group 2 (P < 0.0001). Knee hyperextension ave
raged 7.2 degrees in group 1 and 2.4 degrees in group 2 (P < 0.001). Twenty
-one of 38 patients in group 1 (55%) compared with 8 of 42 patients in grou
p 2 (19%) could touch the thumb to the ipsilateral forearm (P < 0.001). Twe
nty-seven of 38 patients in group 1 (71%) compared with 5 of 42 patients in
group 2 (12%) could extend the thumb past the ulnar border of the clenched
fist (P < 0.001). The authors conclude that a child who demonstrates ligam
entous laxity is more likely to sustain an extension supracondylar humerus
fracture than a distal forearm fracture when he or she falls on the outstre
tched hand to break the force of the fall.