Thoracodorsal Nerve (Full)

nervus thoracodorsalis

The thoracodorsal nerve innervates the latissimus dorsi, entering it at the neurovascular hilum approximately 10-12 cm from the posterior axillary fold. Preservation of the thoracodorsal nerve is a key objective during axillary node dissection for breast cancer — its injury produces latissimus dorsi weakness and loss of the shoulder extension force critical for crutch walking, overhead work, and swimming. The thoracodorsal nerve is the motor supply for the latissimus dorsi free flap.

Region: Chest

Anatomical Data

Origin, Insertion & Supply

Origin	Posterior cord of the brachial plexus (C6, C7, C8)

Clinical Relevance

Clinical Notes

During axillary node dissection, the thoracodorsal nerve is identified running parallel to and just medial to the thoracodorsal artery along the subscapularis muscle surface. Sentinel lymph node biopsy has reduced the incidence of thoracodorsal nerve injury in early breast cancer. In pectoralis major palsy, latissimus dorsi transfer (neurotised by the thoracodorsal nerve) can partially restore shoulder adduction-extension function.

Pathology

Common Injuries & Conditions

Thoracodorsal Nerve Injury in Axillary Dissection

Latissimus dorsi denervation from thoracodorsal nerve damage during axillary lymph node dissection producing shoulder extension and adduction weakness.