Clinical Efficacy Study of Magnesium-Containing Degradable Polymer Bone Repair Material for Bone-Defect Repair After Extremity Bone Tumor Resection

Inclusion Criteria:

* Subjects with bone tumors (benign or borderline) or tumor-like bone lesions of extremities confirmed by imaging and/or pathology, scheduled for surgical resection.
* Bone defects formed after resection of extremity bone tumor, requiring artificial bone repair material for defect filling and reconstruction.
* Age from 18 to 75 years old, regardless of gender.
* Good general preoperative condition and able to tolerate surgical treatment.
* Voluntarily participate in this study, provide written informed consent, and be judged by investigators to comply with study protocol and complete follow-up visits.
* No postoperative local rejection or allergic reaction at the operative site.
* Diameter of bone defect ≤ 6 cm, and product usage volume ≤ 77 cm³.
* Bone defect located in upper extremity (humerus, ulna-radius, carpal bones) or lower extremity (femur, tibia, fibula, ankle, foot bones).

Exclusion Criteria:

* Active local infection at operative site or severe systemic infection.
* Severe bone metabolic diseases that may interfere with bone healing, such as severe osteoporosis or uncontrolled hyperparathyroidism.
* Severe cardiac, hepatic, renal insufficiency or other serious systemic diseases which cannot tolerate surgery or interfere with study evaluation.
* Severe hematological or immune system disorders.
* Pregnant or lactating women.
* Expected survival less than 12 months, or unable to complete at least 12-month follow-up.
* Known or suspected allergy to collagen, hydroxyapatite or other components of bone repair materials.
* Occurrence of local rejection or allergic reaction at operative site after surgery.
* Diameter of bone defect \> 6 cm, or product usage volume \> 77 cm³.
* Any other conditions judged by investigators making the subject unsuitable for enrollment.