Which nerve palsy results in Bishop's Hand deformity?

Bishop's Hand deformity, also known as the "claw hand" deformity, arises primarily from ulnar nerve palsy. This condition occurs when there is damage to the ulnar nerve, which is responsible for innervating the intrinsic muscles of the hand, particularly those that control finger movements, such as the interossei and the ulnar half of the flexor digitorum profundus.

When the ulnar nerve is affected, the person may lose the ability to flex the fourth and fifth fingers at the proximal interphalangeal joints, while the metacarpophalangeal joints remain in extension, often resulting in a characteristic appearance of the hand. The thumb may also adopt a position that makes it difficult to perform pinching actions. This is what leads to the appearance of "Bishop's Hand," where the fingers curl into the palm in a claw-like position.

The other nerves listed have different functions, and their palsies lead to different types of hand deformities. For instance, median nerve palsy results in ape hand deformity, and radial nerve palsy can lead to wrist drop. Musculocutaneous nerve injury does not typically lead to a prominent hand deformity in