In recent years, 3D-printed porous titanium scaffold has become a focus of research in bone defect repair due to their controllable pore structure and good biocompatibility. Its main strategies include pore design to optimize mechanics and bone ingrowth, surface functionalization modification to enhance osseointegration and anti-infection ability, and loading of bioactive molecules to achieve temporal release and promote vascular osteogenic coupling. Individualized precise reconstruction is gradually being carried out in clinical applications, but long-term safety, manufacturing accuracy, and cost-effectiveness remain challenges. This article reviews the research progress of 3D-printed porous titanium scaffold in bone defect repair, summarizes their application advantages and limitations, and looks forward to directions such as intelligent coatings, immune regulation, and artificial intelligence, in order to provide a reference for their clinical translation.
Objective To analyze the effectiveness of single three-dimensional (3D)-printed microporous titanium prostheses and flap combined prostheses implantation in the treatment of large segmental infectious bone defects in limbs. MethodsA retrospective analysis was conducted on the clinical data of 76 patients with large segmental infectious bone defects in limbs who were treated between January 2019 and February 2024 and met the selection criteria. Among them, 51 were male and 25 were female, with an age of (47.7±9.4) years. Of the 76 patients, 51 had no soft tissue defects (single prostheses group), while 25 had associated soft tissue defects (flap combined group). The single prostheses group included 28 cases of tibial bone defects, 11 cases of femoral defects, 5 cases of humeral defects, 4 cases of radial bone defects, and 3 cases of metacarpal, or carpal bone defects, with bone defect length ranging from 3.5 to 28.0 cm. The flap combined group included 3 cases of extensive dorsum of foot soft tissue defects combined with large segmental metatarsal bone defects, 19 cases of lower leg soft tissue defects combined with large segmental tibial bone defects, and 3 cases of hand and forearm soft tissue defects combined with metacarpal, carpal, or radial bone defects, with bone defect length ranging from 3.8 to 32.0 cm and soft tissue defect areas ranging from 8 cm×5 cm to 33 cm×10 cm. In the first stage, vancomycin-loaded bone cement was used to control infection, and flap repair was performed in the flap combined group. In the second stage, 3D-printed microporous titanium prostheses were implanted. Postoperative assessments were performed to evaluate infection control and bone integration, and pain release was evaluated using the visual analogue scale (VAS) score. Results All patients were followed up postoperatively, with an average follow-up time of (35.2±13.4) months. In the 61 lower limb injury patients, the time of standing, walk with crutches, and fully bear weight were (2.2±0.6), (3.9±1.1), and (5.4±1.1) months, respectively. The VAS score at 1 year postoperatively was significantly lower than preoperative one (t=−10.678, P<0.001). At 1 year postoperatively, 69 patients (90.8%) showed no complication such as infection, fracture, prosthesis displacement, or breakage, and X-ray films indicated good integration at the prosthesis-bone interface. According to the Paley scoring system for the healing of infectious bone defects, the results were excellent in 37 cases, good in 29 cases, fair in 3 cases, and poor in 7 cases. In the single prostheses group, during the follow-up, there was 1 case each of femoral prostheses fracture, femoral infection, and tibial infection, with a treatment success rate of 94.1% (48/51). In lower limb injury patients, the time of fully bear weight was (5.0±1.0) months. In the flap combined group, during the follow-up, 1 case of tibial fixation prostheses screw fracture occurred, along with 2 cases of recurrent foot infection in diabetic patients and 1 case of tibial infection. The treatment success rate was 84.0% (21/25). The time of fully bear weight in lower limb injury patients was (5.8±1.2) months. The overall infection eradication rate for all patients was 93.4% (71/76). Conclusion The use of 3D-printed microporous titanium prostheses, either alone or in combination with flaps, for the treatment of large segmental infectious bone defects in the limbs results in good effectiveness with a low incidence of complications. It is a feasible strategy for the reconstruction of infectious bone defects.
Objective To compare the effectiveness of a zero-profile three-dimensiaonal (3D)-printed microporous titanium alloy Cage and a conventional titanium plate combined with a polyether-ether-ketone (PEEK)-Cage in the treatment of single-segment cervical spondylotic myelopathy (CSM) by anterior cervical discectomy and fusion (ACDF). Methods The clinical data of 83 patients with single-segment CSM treated with ACDF between January 2022 and January 2023 were retrospectively analyzed, and they were divided into 3D-ZP group (35 cases, using zero-profile 3D-printed microporous titanium alloy Cage) and CP group (48 cases, using titanium plate in combination with PEEK-Cage). There was no significant difference in gender, age, disease duration, surgical intervertebral space, and preoperative Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score, neck disability index (NDI), vertebral height at the fusion segment, Cobb angle, and other baseline data between the two groups (P>0.05). The operation time, intraoperative blood loss, hospital stay, complications, interbody fusion, and prosthesis subsidence were recorded and compared between the two groups. VAS score, NDI, and JOA score were used to evaluate the improvement of pain and function before operation, at 3 months after operation, and at last follow-up, and the vertebral height at the fusion segment and Cobb angle were measured by imaging. The degree of dysphagia was assessed by the Bazaz dysphagia scale at 1 week and at last follow-up. Results The operation was successfully completed in all the 83 patients. There was no significant difference in intraoperative blood loss and hospital stay between the two groups (P>0.05), but the operation time in the 3D-ZP group was significantly shorter than that in the CP group (P<0.05). Patients in both groups were followed up 24-35 months, with an average of 25.3 months, and there was no significant difference in the follow-up time between the two groups (P>0.05). The incidence and grade of dysphagia in CP group were significantly higher than those in 3D-ZP group at 1 week after operation and at last follow-up (P<0.05). There was no dysphagia in 3D-ZP group at last follow-up. There was no complication such as implant breakage or displacement in both groups. The intervertebral fusion rates of 3D-ZP group and CP group were 65.71% (23/35) and 60.42% (29/48) respectively at 3 months after operation, and there was no significant difference between the two groups [OR (95%CI)=1.256 (0.507, 3.109), P=0.622]. The JOA score, VAS score, and NDI significantly improved in the 3D-ZP group at 3 months and at last follow-up when compared with preoperative ones (P<0.05), but there was no significant difference between the two groups (P>0.05). There was no significant difference in the improvement rate of JOA between the two groups at last follow-up (P>0.05). At 3 months after operation and at last follow-up, the vertebral height at the fusion segment and Cobb angle significantly improved in both groups, and the two indexes in 3D-ZP group were significantly better than those in CP group (P<0.05). At last follow-up, the incidence of prosthesis subsidence in 3D-ZP group (8.57%) was significantly lower than that in CP group (29.16%) (P<0.05). ConclusionThe application of zero-profile 3D-printed Cage and titanium plate combined with PEEK-Cage in single-segment ACDF can both reconstruct the stability of cervical spine and achieve good effectiveness. Compared with the latter, the application of the former in ACDF can shorten the operation time, reduce the incidence of prosthesis subsidence, and reduce the incidence of dysphagia.
ObjectiveTo review the current research and application progress of three-dimentional (3D) printed porous titanium alloy after tumor resection, and provide direction and reference for the follow-up clinical application and basic research of 3D printed porous titanium alloy. MethodsThe related literature on research and application of 3D printed porous titanium alloy after tumor resection in recent years was reviewed from three aspects: performance of simple 3D printed porous titanium alloy, application analysis of simple 3D printed porous titanium alloy after tumor resection, and research progress of anti-tumor 3D printed porous titanium alloy. Results3D printing technology can adjust the pore parameters of porous titanium alloy, so that it has the same biomechanical properties as bone. Appropriate pore parameters are conducive to inducing bone growth, promoting the recovery of skeletal system and related functions, and improving the quality of life of patients after operation. Simple 3D printed porous titanium alloy can more accurately match the bone defect after tumor resection through preoperative personalized design, so that it can closely fit the surgical margin after tumor resection, and improve the accuracy and efficiency of the operation. The early and mid-term follow-up results show that its application reduces the postoperative complications such as implant loosening, subsidence, fracture and so on, and enhances the bone stability. The anti-tumor performance of 3D printed porous titanium alloy mainly includes coating and drug-loading treatment of pure 3D printed porous titanium alloy, and some progress has been made in the basic research stage. ConclusionSimple 3D printed porous titanium alloy is suitable for patients with large and complex bone defects after tumor resection, and the anti-tumor effect of 3D printed porous titanium alloy can be achieved through coating and drug delivery.