Novel application of 3D printed microporous prosthesis to repair humeral nonunion with segmental bone defects: a case report

Abstract

Background: Nonunion of the humeral shaft can turn into bone defects. There is no consensus on the optimal treatment of humeral shaft nonunion with bone defects. Herein, we presented a single case of a patient with a 9.5 cm humerus shaft bone defect treated with a 3D printed Ti6Al4V microporous prosthesis after internal fixation failure of a middle-inferior humerus fracture.Case Description: A 53-year-old female who injured her left upper limb by falling was diagnosed with a fracture of the left humeral shaft. The fracture was treated with open reduction and internal fixation. Nine months postoperatively, radiography examination indicated humeral nonunion with a 9.5 cm segmental bone defect. A 3D printing technology was then used to design and fabricate a customized microporous prosthesis with an intramedullary nail and lateral plates. A two-stage surgical strategy was performed, including radical debridement, temporary fixation for the induced membrane formation, and the implantation of the prosthesis. At 18 months of follow-up, encouraging clinical outcomes were observed. The prosthesis remained stable in the original implantation area and callus formation was found at the contact end of the prosthesis and bone stump. The upper limb functions returned to normal with a satisfactory functional score. Also, no complications were found.Conclusions: Reconstruction with a 3D printed microporous prosthesis might be used as an alternative for the repair of large segmental bone defects of limbs.

Emerging applications of 3D printed microporous prosthesis in nonunion repair: mechanisms and therapeutic potential

“…Traditional repair methods for such fractures include distraction osteogenesis (Ilizarov technique), Masquelet’s induced membrane technique (MIMT), vascularized fibular graft, and the use of titanium mesh. While these methods have been regarded as the gold standard for many years, they each present unique disadvantages ( 4 ). Additionally, many of these treatments rely on bone-bone fusion with repair through bilateral bone integration ( 5 ).…”

“…Thus, the porous nature of 3D printed implants offers a valuable and effective option for the treatment and reconstruction of humeral bone defects due to their ability to compensate for deficiencies of these conventional treatment options. Most recently, Qiu et al expanded on the animal model initially proposed by Zhang et al in their article “Novel application of 3D printed microporous prosthesis to repair humeral nonunion with segmental bone defects: a case report” ( 4 ). Qiu et al presented the use of a 3D printed Ti6Al4V microporous prosthesis in the treatment of a 9.5 cm humerus shaft bone defect following internal fixation failure in a middle-inferior humerus fracture ( 4 ).…”

“…Most recently, Qiu et al expanded on the animal model initially proposed by Zhang et al in their article “Novel application of 3D printed microporous prosthesis to repair humeral nonunion with segmental bone defects: a case report” ( 4 ). Qiu et al presented the use of a 3D printed Ti6Al4V microporous prosthesis in the treatment of a 9.5 cm humerus shaft bone defect following internal fixation failure in a middle-inferior humerus fracture ( 4 ).…”

“…Accounting for approximately 5–8% of fractures ( 10 ), humeral shaft fractures are subject to nonunion in approximately 10% of patients regardless of treatment type ( 11 ). The authors propose a technique that allows for enhanced mechanical strength to support the rehabilitation of a patient-specific defect with the advantages of early mobilization and weight-bearing capability ( 4 ). In this specific case, the large bone defect was localized in the mid and distal humerus, requiring bone reconstruction in both cylindrical and flat portions of the defect, respectively.…”

“…Two months following an open reduction and internal fixation attempting to repair the 9.5 cm humerus defect, radiographs revealed a humeral nonunion ( 4 ). Clinical examination nine months postoperatively revealed two broken screws at the distal end of the humerus, insufficient bone mass mid-humerus, and osteosclerosis at the fractured site.…”