Surgical reconstruction of elbow extension can help restore function in patients with tetraplegia and triceps paralysis because of spinal cord injury. Both posterior deltoid-to-triceps tendon transfer and transfer of the branch of the axillary nerve to the triceps motor branch of the radial nerve have been described for triceps reanimation. This systematic review aimed at reviewing current evidence in the two schools of surgery in terms of their outcome and complication profile. A systematic review was conducted using MEDLINE (1974-2023) and EMBASE (1946-2023) databases. The keyword terms "elbow extension," "triceps," "deltoid," "nerve transfer," "spinal cord injury," "tetraplegia," "quadriplegia," and "tetraplegic" were used in the initial search, which was supplemented with manual searches of the bibliographies of retrieved articles. Twenty studies met our inclusion criteria, with 14 studies (229 limbs) on posterior deltoid-to-triceps tendon transfer, 5 studies (23 limbs) on axillary to radial nerve transfer, and 1 study (1 limb) on combined transfer. For the tendon transfer group, the majority of studies reported a median triceps power of grade 3, with a wide range of failure percentage to reach antigravity (0% to 87.5%). Common complications included gradual stretching of the musculotendinous unit, rupture of the tendon transferred, elbow contracture, and infection. For the nerve transfer group, the majority of studies also reported a median triceps power reaching grade 3. There were no reported complications or loss of power in donor action of shoulder abduction or external rotation. Transfer of the axillary nerve branch to the triceps motor branch of the radial nerve in tetraplegia shows promising results, with comparable triceps muscle power compared to traditional tendon transfer and a low incidence of complication. Systematic Review III.