- See:
- Claw Hand:
- Tendon Excursion:
- Nerve Repair:
- Combined Injuries of the Median and Ulnar Nerves:
- Discussion:
- lesion of ulnar nerve at or near wrist or base of palm will result in paralysis of hypothenar muscles, all interosseous muscles, 1/2 of FPB,
the palmaris brevis, & adductor pollicis;
- in pts w/ low ulnar nerve injury, some intrinsic may continue to function due to martin gruber communication between AIN and the unlnar nerve;
- Clinical Presentation:
- w/ low ulnar nerve palsy, interossei & third & fourth lumbricals are paralyzed;
- there will be loss of hypothenar muscles, interossei, adductor pollicis, and the deep half of the FPB;
- in patients w/ low ulnar nerve injury, some intrinsic f(x) may be maintained due to martin gruber communication between AIN nerve & unlnar nerve;
- there will be loss of 50-80 % of pinch strength, 50% loss of grip strength, loss of lateral deviation of fingers, and loss
of integration of the PIP and MPJ flexion;
- Froment's sign:
- when the patient is asked to adduct the thumb (such as holding a pencil in the web space), patient will instead hyperflex the
IP joint to compensate for loss of the adductor;
- MP Joint Instability:
- weakness of the adductor pollicis leads to instability of the MP joint;
- unopposed action of the thumb extensors leads to MCP hyperextension deformity where as unopposed activity of the thumb flexors
lead to IP joint hyperflexion deformity;
- Clawing is present w/ low ulnar nerve injury:
- also known as Duchenne's sign;
- clawing of ulnar 2 digits occurs, to lesser degree, long finger cannot be completely extended;
- there is hyperextension of MP joint, because of unopposed action of long extensors;
- unopposed long extensors cannot bring about any extension of IP jonts because their energy is dissipated in hyperextending MP joints;
- IP joints are flexed due to unopposed action of long flexors, since extensor expansion is lax due to of paralysis of interossei & lumbricals;
- thus clawing occurs, w/ hyperextension of MP joints & flexion of IP joints;
- wartenberg's sign (little finger abduction)
- due to unopposed ulnar insertion of extensor digiti quinti;
- little finger more often has more severe claw deformity, as opposed to ring finger,
because of inherent increased laxity in little finger MP joint volar plate;
- in addition, approx 50% of pts have median nerve cross innervation to lumbricals to ring finger,
thus preventing claw deformity of the ring finger;
- diff dx:
- rupture of the deep transverse metacarpal ligament;
- note that extreme ulnar deviation of the little finger with extension may indicate a rupture of the deep transverse metacarpal ligament;
- references:
- Closed rupture of the deep transverse metacarpal ligament: diagnosis and management.
- Abducted, hyperextended small finger deformity of noneurologic etiology.
- treatment:
- transfer EDQ to radial side of digit, volar to intermetacarpal ligament if claw deformity exists;
- as a requirement for this procedure, one must be sure that pt has good EDC function to the little finger;
- reference:
The abducted little finger in low ulnar nerve palsy.
- Operative Procedures:
- adductor pollicis deficit:
- adductor pollicis substitution by FDS of long finger passed thru interosseous membrane, over & under ECU as distal pulley;
- crossing beneath EDC, and into adductor insertion, anchoring tendon into bone;
- boyles procedure:
- transfer of BR (reroute around 3rd MC to adductor pollicis);
- mp arthrodesis
- if tendon transfer is not possible due to of lack of motors, MP arthrodesis of hypermobile thumb MP joint will provide
stability and some improvement in strength;
- intrinsic muscles deficit:
- burkhalter transfer
- APL transfer to first dorsal interosseous;
- reference:
Abductor pollicis longus transfer for replacement of first dorsal interosseous.
Studies on the hand in ulnar nerve paralysis. A clinical experimental investigation in normal and anomalous innervation.
Tendon transfer for median and ulnar nerve paralysis.
Reconstruction of pinch in ulnar intrinsic palsy.
Brown PW. Orthop Clin North Am. 1974:5:323.
Tendon transfers for ulnar nerve palsy. Evaluation of results and practical treatment considerations