The examination of hand for neuropathies is commonly encountered at OSCE stations. Ulnar Claw-hand is a very characteristic finding in Ulnar nerve palsy.
Firstly, introduce yourself and get consent before you proceed to examine the patient.
Given below is a targeted examination for Ulnar nerve palsy. But remember to examine other nerves (Median & Radial) to exclude multiple nerve involvement.
There is marked clawing of the ring and little fingers of the right hand and there is wasting of hypothenar eminence with dorsal guttering, but the thenar eminence is not affected. The actions of palmar and dorsal interossei are impaired and Froment’s sign is positive.
The opposition of the thumb and finger extension is intact. There is an area of sensory loss over the palmar aspect of the medial side of the hand and medial one and half fingers. There is no hypopigmented patches or ulnar nerve thickening and there are no visible scars on the forearm.
So my tentative diagnosis is right-sided Ulnar nerve palsy, probably a lower lesion.
It is the hyperextension of the metacarpophalangeal joints and flexion of proximal and distal interphalangeal joints.
It is due to paralyzed Interossei and Lumbricals with unopposed action of long flexors and extensors.
The clawing is only obvious in medial two fingers (Because lateral two Lumbricals which are supplied by the median nerve are spared).
Surprisingly, high division of the ulnar nerve (anywhere hand’s breadth above the wrist) causes less clawing than the lower lesions.
In higher lesions the innervation to the medial half of Flexor Digitorum Profundus is also lost, causing less intense flexion of the fingers.
From the degree of clawing and the area of sensory involvement (see examination).
1. Flexor Carpi Ulnaris.
2. Medial half of Flexor Digitorum Profundus.
3. All Palmar Interossei.
4. All dorsal Interossei.
5. 3rd & 4th Lumbricals.
6. Adductor Pollicis
The patient tries to compensate for the ‘lost’ adduction of the thumb by flexion of it (with Flexor Pollicis Longus which is supplied by the Median nerve).
1. Leprosy (often bilateral).
2. Laceration over the wrist or anywhere along its course.
3. Fracture medial epicondyle.
4. Dislocation of elbow.
5. Cubital tunnel syndrome.
6. Degenerative arthritis.
7. Malunion of fractures of the lower end of the humerus (Tardae Ulna nerve palsy).
1. Ulnar nerve decompression.
2. Ulnar nerve anterior transposition.
3. Medial epicondylectomy.