Evaluation of the Safety and Efficacy of Artificial Bone Repair Materials for Repair of Long Bone Defects in the Extremities: A Prospective, Randomized Controlled, Single-Blind, Non-Inferiority Clinical Trial

Inclusion Criteria:

1. Age ≥ 18 years old and ≤ 60 years old, regardless of sex;
2. Cavitary bone defects in the limbs requiring bone grafting treatment;
3. Bone defect volume ≥ 1 cm³ and ≤ 8 cm³, with only one bone defect requiring intervention;
4. Subjects or their legal guardians can understand the study objectives, demonstrate sufficient compliance with the study protocol, and sign the informed consent form.

Exclusion Criteria:

1. Open fractures with wound contamination;
2. Repair of infectious bone defects;
3. Structural bone grafting required at the defect site;
4. Osteofascial compartment syndrome in the affected limb scheduled for surgery;
5. Presence of systemic infection, uncontrolled local infection at the surgical site, malignant tumor (including metastatic tumors) at the defect site, osteonecrosis at the defect site, severe nerve/soft tissue/vascular injury at the defect site, confirmed severe malnutrition, or dysfunction/failure of other vital organs;
6. Calcium and phosphorus metabolic abnormalities (calcium/phosphorus levels > 1.5 times the upper limit of normal values);
7. History of diabetes with fasting blood glucose ≥ 6.1 mmol/L;
8. Coagulation dysfunction (prothrombin time [PT] or activated partial thromboplastin time [APTT] > 2 times the upper limit of normal values);
9. Use of chemotherapeutic agents or receipt of radiotherapy within 3 months prior to enrollment;
10. Cumulative use of corticosteroids or growth factors for ≥ 14 days within 1 month prior to enrollment;
11. Long-term use of sedative-hypnotic drugs (continuous use for > 3 months) or non-steroidal anti-inflammatory drugs (NSAIDs, continuous use for > 3 months);
12. Known allergy to bovine-derived materials or collagen products;
13. Pregnant or lactating females;
14. Participation in other interventional clinical trials for drugs or medical devices within 1 month prior to enrollment;
15. Any other conditions where investigators, in their professional judgment, deem the subject ineligible to participate in the trial for the subject's safety or benefit.