A spos-person presents with laceration of wrist but with no vascular injury. On examination, a structure lateral to flexor digitorum superficialis is found to be injured. What action he most likely cannot perform (JIPMER May 2019)
Abduction of 2nd digit
Adduction of 2nd digit
Opposition of thumb
Flexion of thumb
- Whenever we find laceration of wrist, most commonly damaged nerve is median nerve. (sometimes - ulnar nerve)- As the question is stating that lateral to flexor digitorum superficialis is injured, it is clearly a case of median nerve injury.- Flexor digitorum superficialis tendons (for folding is fingers) - pass deep to flexor retinaculum/ Transverse carpal ligament.- Deep to that median nerve is also passing just lateral to flexor digitorum superficialis tendon.- Median nerve supplies thenar muscles (like abductor pollicis brevis, opponens pollicis) & also give cutaneous supply to 31/2 fingers skin.- In median nerve injury, there would be paralysis of opponens pollicis resulting in problem of thumb opposition - Sometimes, wrist laceration lead to ulnar nerve injury.* Ulnar nerve & ulnar aery runs superficial to flexor retinaculum in Guyon's canal * Inside Guyon's canal, it divides into superficial & deep branches.* Superficial branch - gives 11/2 fingers skin supply* Deep branch - Supplies Hypothenar muscles like Digiti minimi muscles, all interossei & 2 lumbricals.- These are lost in ulnar nerve injury- Ulnar aery forms superficial palmar arch- Radial aery running with radius bone, become content of anatomical snuff box & gives deep palmar arch.- Abduction to 2nd digit - Need dorsal interossei - supplied by ulnar. N- Adduction of 2nd digit - Need palmar interossei - supplied by ulnar. N (PADD)- Flexion of thumb - done by flexor pollicis longus - supplied by anterior interosseous nerve which is branch of median nerve
JIPMER 2019