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

This investigator‐initiated single‐center prospective randomized open‐labelnon‐inferiority trial plans to recruit 72 adult subjects with bone defects followingextremity bone tumor or tumor‐like lesion resection. Randomization will be stratified byupper‐limb versus lower‐limb defect location to balance mechanical load confoundingbetween groups, with 36 subjects allocated to each arm.After standard tumor resection, the experimental group receives implantation ofmagnesium‐containing degradable polymer bone repair material. The control group usescommercially available conventional bone repair material without magnesium.Post‐operative standardized care protocols including antibiotic prophylaxis, stepwiseanalgesia regimen, wound dressing and weight‐bearing rehabilitation are identical forboth groups. Opioid consumption will be converted to morphine‐equivalent dose for primaryendpoint analysis, with a pre‐specified non‐inferiority margin of 9.726 mg morphineequivalent. At 1‐, 3‐ and 6‐month follow‐ups, thin‐slice CT scans are performed forquantitative 3D reconstruction to assess new bone formation volume. Two independentradiology reviewers blinded to group assignment conduct volumetric measurement to reduceassessment bias. Surgical‐site infection is defined by combined clinical manifestation,laboratory tests and bacterial culture results. Local tumor recurrence is confirmed byimaging or pathological biopsy. Safety assessments cover material‐related adversereactions, implant‐associated complications and surgery‐related adverseevents.Statistical analyses will test non‐inferiority for the primary endpoint.Continuous secondary outcomes will be analyzed using t‐test or rank‐sum test; categoricalvariables will adopt Chi‐square test or Fisher's exact test. Subgroup analyses forupper‐limb and lower‐limb subgroups will be performed. Both full‐analysis set andper‐protocol set will be used for efficacy assessment. This trial follows the Declarationof Helsinki and has obtained institutional ethics committee approval. Written informedconsent will be obtained from each participant before enrolment.