Distal nerve transfer for thenar palsy: A cadaveric study

Area of Science:

• Hand surgery
• Neuroanatomy
• Microsurgery

Background:

• Severe proximal median nerve palsies lead to thenar atrophy and loss of thumb function.
• Tendon transfers have limitations; distal nerve transfers offer a promising alternative treatment.
• Thenar muscle reanimation is crucial for restoring hand function.

Purpose of the Study:

• To evaluate the anatomical suitability of distal ulnar nerve branches for thenar muscle reanimation.
• To assess the potential of using ulnar nerve branches for median nerve palsy treatment.
• To validate distal nerve transfer as a viable surgical option.

Main Methods:

• Cadaveric dissection of 16 embalmed hands.
• Assessment of ulnar motor branches to flexor digiti minimi brevis (FDMBn) and third lumbrical (3rdLn) for transfer.
• Measurement of nerve overlap, length, width, and diameter for coaptation success with the recurrent branch of the median nerve (RMN).

Main Results:

• The RMN had a mean transferable length of 20.7 mm and width of 1.0 mm.
• The FDMBn and 3rdLn offered transferable lengths of 13.8 mm and 24.1 mm, respectively.
• Significant overlap was observed between ulnar nerve branches and the RMN, indicating coaptation feasibility.

Conclusions:

• Distal ulnar nerve transfers to the RMN are anatomically feasible for thenar muscle reanimation.
• The FDMBn and 3rdLn are suitable donor nerves with minimal morbidity.
• This technique offers a promising surgical approach for median nerve palsy with potential for good functional recovery.