Snapshot A 32-year-old woman presents to the emergency room with severe right arm pain after being involved in a motor vehicle collision. She has a comminuted open fracture of the right distal radius and ulna. She is taken to the operating room where lesions to the distal ulnar artery and nerve are noted. She undergoes multiple surgical procedures over the following several months until her radius and ulna appear well healed. However, she has residual hand weakness and is unable to completely open her hand after making a fist. On exam, her 4th and 5th metacarpophalangeal joints are hyperextended while her 4th and 5th interphalangeal joints are flexed. Introduction Lesions to different nerves of the upper extremity will lead to specific hand distortions ulnar claw hand hand of benediction Klumpke total claw hand Relevant anatomy muscles lumbricals login to view 6 more bullets extensor digitorum communis (EDC) login to view 4 more bullets flexor digitorum superficialis (FDS) login to view 4 more bullets flexor digitorum profundus (FDP) login to view 5 more bullets dorsal and palmar interossei login to view 5 more bullets thenar eminence musculature login to view 9 more bullets Ulnar Claw Hand Physical exam 4th and 5th MCP joints are extended 4th and 5th PIP and DIP joints are flexed weakness in finger abduction and adduction patient is able to make a fist but is not able to completely open their 4th and 5th digits Pathoanatomy nerve involved distal ulnar nerve (at the wrist) muscles involved weakened 4th and 5th lumbricals weakened dorsal and palmar interossei Hand of Benediction Physical exam 2nd and 3rd MCP, PIP, and DIP joints are extended weakness in thumb abduction and opposition patient cannot make a fist due to inability to flex 2nd and 3rd digits Pathoanatomy nerve involved median nerve at the forearm or elbow muscles involved weakened 2nd and 3rd lumbricals weakened FDP to 2nd and 3rd digits weakened thenar musculature Klumpke Total Claw Hand Physical exam MCP joints are hyperextended PIP and DIP joints are flexed wrist is hyperextended weakness in thumb abduction and opposition forearm is supinated Pathoanatomy nerve involved lower trunk of the brachial plexus (C8/T1) muscles involved all intrinsic muscles of the hand login to view 3 more bullets wrist flexors forearm pronators