DESIGN AND EVALUATION OF A PATIENT-SPECIFIC BIODEGRADABLE SCAFFOLD FOR 5TH METACARPAL ENCHONDROMA RECONSTRUCTION: 3D-PRINTED SCAFFOLD FOR METACARPAL ENCHONDROMA

Background: Enchondroma of the metacarpal can compromise bone integrity and hand function, requiring surgical excision and reconstruction. This study presents a patient-specific computational-to-clinical workflow for the design, fabrication, and clinical evaluation of a biodegradable poly-L-lactic acid (PLLA) scaffold for reconstruction of a fifth metacarpal defect following enchondroma excision.

Methods: Bilateral computed tomography (CT) scans were acquired, and the healthy contralateral metacarpal was mirrored to generate a patient-specific anatomical model. A hollow modular PLLA scaffold was designed using computer-aided design, mechanically optimized through ASTM D695 compression testing and finite element analysis (FEA), and fabricated using fused deposition modeling. Following tumor excision, the scaffold was implanted with autologous bone marrow aspirate and osteoconductive graft material and stabilized using a K-wire. Clinical follow-up included serial radiographic assessment and scanning electron microscopy (SEM) analysis of a retrieved scaffold specimen after 18 months.

Results: Mechanical testing and FEA identified a 2[Formula: see text]mm wall thickness as the optimum scaffold configuration, with numerical predictions agreeing with experimental results within [Formula: see text]. Radiographic follow-up at 31 and 46 weeks demonstrated progressive mineralization and osteointegration within the scaffold cavity. SEM analysis of the scaffold retrieved after 18 months revealed surface erosion and a residual wall thickness of approximately 733[Formula: see text][Formula: see text]m, corresponding to an approximately 63% reduction from the original 2[Formula: see text]mm wall thickness, confirming controlled in vivo biodegradation while maintaining structural integrity.

Conclusions: The proposed patient-specific PLLA scaffold and computational-to-clinical workflow demonstrated preliminary feasibility for reconstruction of metacarpal bone defects following benign tumor excision. The scaffold provided temporary mechanical support while facilitating guided bone regeneration and progressive material resorption. This integrated design and evaluation strategy may provide a promising framework for the development of personalized biodegradable orthopedic implants and warrants further validation through larger clinical studies.