RT Book, Section
A1 Breed, Meghan
A1 Fitch, Robert Warne
A2 Knoop, Kevin J.
A2 Stack, Lawrence B.
A2 Storrow, Alan B.
A2 Thurman, R. Jason
SR Print(0)
ID 1181041967
T1 Peripheral Nerve Injury
T2 The Atlas of Emergency Medicine, 5e
YR 2021
FD 2021
PB McGraw-Hill
PP New York, NY
SN 9781260134940
LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1181041967
RD 2024/04/16
AB Chronic  ulnar  nerve  injury  results  in  the  classic  claw-hand  (intrinsic  minus)  deformity  due  to  atrophy  and  contracture  of  the  lumbrical  and  interosseus  hand  muscles.  The  deformity  is  formed  by  MCP  joint  hyperextension  and  flexion  at  the  PIP  and  DIP  joints  of  the  4th  and  5th  digits.  There  is  wasting  of  the  interosseous  and  hypothenar  muscles,  as  well  as  the  hypothenar  eminence.  The  acutely  injured  patient  is  unable  to  abduct  or  adduct  the  digits.  Chronic  median  nerve  damage  also  results  in  the  claw-hand  deformity,  but  to  the  2nd  and  3rd  digits  with  associated  atrophy  of  the  thenar.  Acute  and  chronic  damage  to  the  proximal  portion  of  the  median  nerve  results  in  weakness  of  wrist  flexion,  forearm  pronation,  thumb  apposition,  and  flexion  of  the  1st  three  digits.