The purpose of this study is to investigate the efficacy and safety of NeuroRegen Scaffold with bone marrow mononuclear cells (BMMCs) on neurological recovery following chronic and complete spinal cord injury, compared to the treatment of surgical intradural decompression and adhesiolysis only.

Inclusion Criteria:

1. Completely spinal cord injury at the thoracic level as assessed by magnetic resonance imaging (MRI) and electrophysiology.
2. ASIA Impairment Scale (AIS) grade A.
3. Male or female, 18-60 years old.
4. No significant further improvement after injury and rehabilitation.
5. Patients with normal peripheral nerve function and without muscle atrophy.
6. Cardiovascular, respiratory, liver, kidney functions and laboratory examinations are within normal ranges.
7. No brain disease or mental disorder.
8. Ability and willingness to regular visit to hospital and follow up during the protocol procedures.
9. Patients signed informed consent.

Exclusion Criteria:

1. A current diagnosis of any primary diseases affecting limb functions (e.g., traumatic brain injury, cerebral hemorrhage, cognitive disorders or other central nervous system diseases).
2. Patients without any rehabilitation train after injury.
3. Remarkable muscle atrophy or fibrosis.
4. Degeneration of peripheral nerve function.
5. Allergic constitution.
6. Participation in any immunomodulator therapy or experimental drug treatment within 60 days prior to study.
7. Suffering diabetes, autoimmune diseases, tumor or severe hypertension.
8. Patients with severe heart, lung, liver or renal dysfunction are unable to meet the surgery standards.
9. Severe bleeding tendency or abnormal coagulation function.
10. Inflammation or skin ulcers at the surgical site.
11. Lactating and pregnant woman.
12. Poor compliance, difficult to complete the study.
13. Any other conditions that might increase the risk of subjects or interfere with the clinical trial.