Magnesium Alloy Scaffold With Controlled Degradation for Periarticular Bone Defects

This prospective, multi-center, randomized controlled clinical trial is designed to evaluate the effectiveness and safety of a biodegradable magnesium alloy scaffold with controlled degradation for the treatment of periarticular bone defects of the extremities. Adults with proximal humeral fractures, distal radius fractures, or tibial plateau fractures associated with bone defects and requiring surgical treatment will be enrolled. A total of 120 participants will be randomly assigned in a 1:1 ratio to the experimental group or the control group. Participants in the experimental group will undergo open reduction and internal fixation with implantation of a customized magnesium alloy scaffold into the bone defect. Participants in the control group will undergo conventional open reduction and internal fixation with calcium sulfate bone graft substitute used to fill the bone defect. Participants will be followed for up to 48 weeks after surgery. The study will primarily evaluate bone healing, and will also assess joint function, wound healing, degradation of the magnesium alloy scaffold, device performance, laboratory parameters, and adverse events.

Inclusion Criteria: 1. Age 18 years or older, regardless of sex. 2. Radiographically confirmed proximal humerus fracture, tibial plateau fracture, or distal radius fracture associated with a bone defect and requiring surgical treatment. 3. Willing to participate in the clinical trial and able to provide written informed consent. Exclusion Criteria: 1. Active systemic infection or active infection at the planned surgical site that may interfere with surgery. 2. Pathological fracture, compartment syndrome, osteomyelitis, or severe soft-tissue, vascular, or nerve injury. 3. History of allergy or hypersensitivity to magnesium alloy or titanium alloy implant materials. 4. Psychiatric illness, inability to comply with study procedures for any reason, or unwillingness or inability to comply with required activity restrictions. 5. Drug abuse or alcohol abuse, or inability to refrain from smoking during fracture healing. 6. Women who are pregnant or breastfeeding, or women planning to become pregnant during the study period. 7. Any other condition that, in the investigator's judgment, makes the participant unsuitable for this clinical trial.