<p>Intercalary Reconstruction of the “Ultra-Critical Sized Bone Defect” by 3D-Printed Porous Prosthesis After Resection of Tibial Malignant Tumor</p>

Abstract

This study aimed to evaluate the early stability, limb function, and mechanical complications of 3D-printed porous prosthetic reconstruction for "ultra-critical sized bone defects" following intercalary tibial tumor resections. Methods: This study defined an "ultra-critical sized bone defect" in the tibia when the length of segmental defect in the tibia was >15.0 cm or >60% of the full tibia and the length of the residual fragment in proximal or distal tibia was between 0.5 cm and 4.0 cm. Thus, five patients with "ultra-critical sized bone defects" following an intercalary tibial malignant tumor resection treated with 3D-printed porous prosthesis between June 2014 and June 2018 were retrospectively reviewed. Patient information, implants design and fabrication, surgical procedures, and early clinical outcome data were collected and evaluated. Results: Among the five patients, three were male and two were female, with an average age of 30.2 years. Pathological diagnoses were two osteosarcomas, one Ewing sarcoma, one pseudo-myogenic hemangioendothelioma, and one undifferentiated pleomorphic sarcoma . The average length of the bone defects following tumor resection was 22.8cm, and the average length of ultra-short residual bone was 2.65cm (range=0.6cm-3.8cm). The mean follow-up time was 27.6 months (range=14.0-62.0 months). Early biological fixation was achieved in all five patients. The average time of clinical osseointegration at the bone-porous interface was 3.2 months. All patients were reported to be pain free and have no limitations in their walking distance. No prosthetic mechanical complications were observed. Conclusion: Reconstruction of the "ultra-critical sized bone defect" after an intercalary tibial tumor resection using 3D-printed porous prosthesis achieved satisfactory overall early biological fixation and limb function. Excellent primary stability and the following rigid biological fixation were key factors for success. The outcomes of this study were supposed to support further clinical application and evaluation of 3D-printed porous prosthetic reconstruction for "ultra-critical sized bone defects" in the tibia.

Recent Developments of Biomaterials for Additive Manufacturing of Bone Scaffolds

“…reported that five patients with critical‐sized bone defects (average length was 22.8 cm) after intercalary tibial tumor resection were implanted using 3D‐printed porous titanium prosthetic. [ 260 ] After a mean of 27.6 months follow‐up, neither tumor recurrence nor prosthetic mechanical complications was observed. Moreover, the 3D‐printed bone tumor resection guide could be beneficial to shape the bone allograft and 3D print the implant to fit the bone defect and personalize for a specific patient, leading to the reduced surgical time.…”

Hip-Preserved Reconstruction Using a Customized Cementless Intercalary Endoprosthesis With an Intra-Neck Curved Stem in Patients With an Ultrashort Proximal Femur: Midterm Follow-Up Outcomes

“…Compared with a straight stem, the offset distance of an INCS is smaller; therefore, the bending moment is also smaller, which may be an important factor in decreasing the rate of aseptic loosening of the endoprosthesis ( Wyatt et al, 2019 ). (3) The INCS is coated with hydroxyapatite or 3D-printed porous titanium, which can facilitate biological bone ingrowth at the bone–prosthesis interface ( Van der Stok et al, 2013 ; Lu et al, 2018 ; Zhao et al, 2020 ). (4) The curved stem we used has two fins, symmetrically arranged in the medial and lateral planes at the base of the stem, providing guidance for implantation and an additional derotational force ( Figure 4C ).…”

Is three-dimensional–printed custom-made ultra-short stem with a porous structure an acceptable reconstructive alternative in peri-knee metaphysis for the tumorous bone defect?

“…At last, the muscles and soft tissue were sutured tightly layer by layer. Meanwhile, in the proximal tibia, rotation of gastrocnemius myocutaneous flap and free skin grafting were performed when necessary to ensure soft tissue coverage [ 40 ].…”

“…Our previous study has reported the application of 3D-printed intercalary endoprosthesis in tibial ultra-critical bone defect with a bone stump under 4-cm length [ 40 ]. In this study, we designed a series of 3D-printed custom-made ultra-short stems with a porous structure for peri-knee metaphysis with a bone stump ranging from 4- to 10-cm length.…”