This is a multicenter, 1:1 randomized, prospective, comparative study in participants requiring reconstruction of a mixed or motor nerve in the upper extremity. This study will consist of a screening visit, an operative visit, and 9 post-operative follow-up visits at Week 4, and Months 3, 6, 9, 12, 15, 18, 21, and 24.

This is a multicenter, 1:1 randomized, prospective, evaluator blinded, comparative study in participants requiring reconstruction of a mixed or motor nerve in the upper extremity. The study will assess recovery of motor and sensory function via MRCC score for nerve repairs with Avance Nerve Graft (Study Treatment) and sural nerve autograft (Comparator) through non-inferiority analyses. Participants will be considered enrolled to the study once all screening and eligibility criteria have been met and the participant has been centrally randomized to either Avance Nerve Graft or sural nerve autograft; Inclusion and exclusion criteria are defined at decision points for pre-operative screening eligibility and operative eligibility. This study will consist of a screening visit, an operative visit, and 9 post-operative follow-up visits at Week 4, and Months 3, 6, 9, 12, 15, 18, 21, and 24.

Inclusion Criteria:

Study Participant Criteria

1. Be ≥ 18 years of age at the time of consent;

2. Willing and able to comply with all aspects of the treatment and evaluation schedule over a 24-month duration;

3. Provide documented Institutional Review Board (IRB)/Independent Ethics Committee (IEC)-approved informed consent prior to initiation of any study procedures;

   Injury/Repair Criteria for Each Nerve

4. Primary or secondary nerve injury repair with sural nerve autograft or Avance Nerve Graft for fully transected reconstruction of the following upper extremity mixed and/or motor nerve(s):

   • Median nerve: proximal nerve stump within 20 cm from the center point of the thenar eminence and distal to the crease of the elbow;
   • Anterior interosseous nerve;
   • Median nerve recurrent motor branch;
   • Radial nerve: proximal nerve stump within 20 cm of the center of the forearm (midpoint between the tip of the olecranon and the styloid process) and distal to the mid-humerus;
   • Posterior interosseous nerve.

5. Zone of injury of eligible nerve(s) resectable to healthy nerve both distally and proximally and within the anatomical regions of Inclusion Criterion #4;

6. In study participants with multiple eligible nerve repairs, repair of all eligible nerves completed with the same study treatment, either Avance Nerve Graft or sural nerve autograft;

7. Measured nerve gap(s) following resection > 25 mm;

8. Nerve(s) repaired ≤ 120 days post injury;

9. Undergo coaptation on both the proximal and distal portion of the nerve gap(s) per the USPI for Avance Nerve Graft and per standard of care for sural nerve autograft; and

10. Either treatment method, Avance Nerve Graft or sural nerve autograft, is a viable option for all eligible nerve repair(s) (i.e., volume of injured nerve[s] does not exceed availability of sural nerve autograft for reconstruction, study participants are not treated with a combination of treatment types).

Exclusion Criteria:

Study Participant Criteria

1. Currently enrolled in another clinical study that may interfere with treatment, assessment of recovery, or participation in this study;

2. Deformities or injuries of the limb, hand, or digits that affect both the primary and secondary assessments for eligible nerve repair(s);

3. History of neuropathy of any etiology, diabetic neuropathy or any other known neuropathy including compressive/traumatic neuropathies affecting the target limb;

4. History of progressive neurodegenerative or autoimmune disorder affecting peripheral nerve or motor function (e.g., amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease);

5. History of chronic ischemic condition of the upper extremity;

6. Expected use of medication during the study that is known to impact nerve regeneration or to cause peripheral neuropathy;

7. Undergoing or expected to undergo treatment with chemotherapy, radiation therapy, or other known treatment which affects the growth of neural and/or vascular systems;

8. Participant is unlikely to comply with all study requirements and standard medical care procedures for the duration of the study schedule;

   Injury/Repair Criteria for Each Nerve

9. Median nerve repairs where the ulnar nerve has been transected due to injury or repair;

10. Repair(s) of a sensory-only proximal nerve stump;

11. Incomplete nerve transections;

12. Multilevel nerve injury pattern requiring two or more isolated reconstructions along the nerve pathway (for example, reconstruction of median nerve in forearm and recurrent motor branch resulting in repair pattern of graft to native nerve to graft to distal target);

13. Inadequate soft tissue coverage or extensive soft tissue injury which will impair recovery assessment;

14. Nerve avulsion injuries and nerve traction injuries resulting in rupture of the nerve;

15. Replantation/amputation of the limb, hand, or digits involved in both the primary and secondary assessments for eligible nerve repair(s);

16. Nerve repairs utilizing either end-to-side or side-to-side coaptation techniques;

17. Nerve transfer, tendon transfer, or other concomitant treatment at the time of nerve repair that affects assessment of function of the innervated muscle organ;

18. Use of coaptation devices that include metallic components or activated polymers and coaptations completed with fibrin glue only; and

19. Injuries with vascular damage resulting in inadequate perfusion despite repair (i.e., both radial and ulnar arteries injured [one injured artery is allowed]).

Blinding of the surgeon, study participant and clinical research coordinator to the treatment group is not possible, and attempts will be made to maintain the blind for the upper extremity sensory and motor function outcomes assessor. Repair of a nerve discontinuity necessarily requires the surgeon to perform one of two procedures with distinct procedural characteristics that differ in operative steps, surgical locations, and graft appearance, making surgeon blinding infeasible. The study participant will also be unblinded due to the presence or absence of a donor-site harvest wound and a newly created functional deficit at the autograft donor site. The assessments for sensory and motor function will be conducted by a qualified assessor who has been blinded to the participant's treatment group. The lower extremity assessments for participants in the sural nerve autograft group will be conducted by a separate, qualified assessor who is not blinded to the participant's treatment group.