Objective To evaluate the feasibility and short-term effectiveness of three-dimensional (3D) printed titanium-alloy prosthesis reconstruction after the distal tibia tumor segment resection. Methods The clinical data of 6 patients with bone defect after distal tibia tumor segment resection treated with 3D printed titanium-alloy prosthesis reconstruction and tibiotalar joint fusion between January 2020 and December 2021 were retrospectively analyzed. There were 2 males and 4 females; the age ranged from 12 to 35 years, with an average of 18.5 years. Among them, 4 cases were osteosarcoma, 1 case was Ewing sarcoma, and 1 case was giant cell tumor of bone. The Enneking staging was stage ⅡA in 3 cases, stage ⅡB in 2 cases, and stage Ⅲ in 1 case. The disease duration was 2-5 months (mean, 3.2 months). All patients received preoperative neoadjuvant therapy, and patients with osteosarcoma and Ewing sarcoma started chemotherapy at3 weeks after operation. The systemic and local tumor conditions and prosthesis conditions were evaluated regularly after operation. The Musculoskeletal Tumor Society (MSTS) score and the American Orthopaedic Foot and Ankle Society (AOFAS) score were used to evaluate the lower extremity and ankle function. Results All patients were followed up 8-26 months, with an average of 15.6 months. There was no local recurrence and distant metastasis during the follow-up. The ankle joints of 5 cases were all in 90° functional position at last follow-up, and there was no complication such as prosthesis loosening and fracture; the ankle joint fusion was stable, the local bone ingrowth was good, and the daily activities could be completed, but the ankle range of motion was limited and the ankle joint was stiff. The MSTS score ranged from 22 to 26, with an average of 24, and 3 cases were evaluated as excellent and 2 cases were good; the AOFAS score ranged from 71 to 86, with an average of 80.6, and 4 cases were evaluated as good and 1 case was fair. One patient had severe periprosthetic infection at 2 months after operation, resulting in failure of prosthesis implantation, pain in limb movement, and poor ankle function; MSTS score was 12, AOFAS score was 50, and both were evaluated as poor; distraction osteogenesis was performed after removal of prosthesis and infection control, at present, it was still in the process of distraction osteogenesis, and local osteogenesis was acceptable. Conclusion Using 3D printed titanium-alloy prosthesis and tibiotalar joint fusion to reconstruct the bone defect after distal tibia tumor segment resection has satisfactory mechanical stability and function, and is one of the effective distal tibial limb salvage methods.
Objective To investigate the effectiveness of three-dimensional (3D)-printed hemi-pelvic prosthesis for revision of aseptic loosening or screw fracture of modular hemi-pelvic prosthesis. MethodsBetween February 2017 and January 2020, 11 patients with aseptic loosening or screw fracture of modular hemi-pelvic prosthesis were revised using 3D-printed hemi-pelvic prostheses. There were 7 males and 4 females with an average age of 44 years (range, 25-60 years). In the first operation, all patients underwent total tumor resection, modular hemi-pelvic prosthesis reconstruction, and autologous femoral head transplantation. According to the Enneking pelvic partition system, 8 cases were resected in zones Ⅰ+Ⅱ and 3 cases in zones Ⅰ+Ⅱ+Ⅲ. The interval from the initial operation to this revision ranged from 14.3-66.2 months, with an average of 35.8 months. The operation time, the amount of intraoperative bleeding, and the occurrence of complications were recorded. At 6 months after the first operation, before revision, and at last follow-up, the American Musculoskeletal Tumor Society (MSTS) score and Harris score were used to evaluate the recovery of lower limb function. The pain-free walking distance of patients without brace assistance was recorded at last follow-up. X-ray films were taken at 1 month after the first operation, before revision, and at 1 month after revision, the acetabulum position was assessed by the differences in weight arm and cup height between bilateral hip joints. At last follow-up, the digital X-ray tomography was taken to evaluate the prosthesis-bone integration and the occurrence of aseptic loosening. Results The operation time was 182.6-238.0 minutes (mean, 197.4 minutes). The amount of intraoperative bleeding was 400-860 mL (mean, 550.0 mL). All incisions healed by first intention with no infection, hip dislocation, nerve damage, or vascular-related adverse events. The MSTS score and Harris score at last follow-up were significantly higher than those at 6 months after the first operation and before revision (P<0.05), while the score before revision was significantly lower than that at 6 months after the first operation (P<0.05). At last follow-up, the patients were able to walk more than 1 000 meters painlessly without brace assistance. Imaging review showed that the difference of cup height at 1 month after revision was significantly lower than that at 1 month after the first operation and before revision, and at 1 month after the first operation than before revision operation, and the differences were significant (P<0.05). There was no significant difference in the difference of weight arm among three time points (P>0.05). All prostheses were well integrated, and no aseptic loosening of the prosthesis or screw fracture occurred. Conclusion Revision with 3D-printed hemi-pelvic prostheses benefited in reconstructing stable pelvic ring and natural bodyweight transmission for patients encountering the aseptic loosening or screw fracture of modular hemi-pelvic prosthesis. Early postoperative rehabilitation training can maximize the recovery of patient limb function, reduce pain during walking, and reduce the incidence of complications.
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.
Objective To review the application of three-dimensional (3D) printing patient-specific cutting guides (PSCG) in open-wedge high tibial osteotomy (OWHTO). Methods The domestic and foreign literature about the use of 3D printing PSCG to assist the OWHTO in recent years was reviewed, and the effectiveness of different types of 3D printing PSCG to assist OWHTO was summarized. Results Many scholars design and use different 3D printing PSCGs to confirm the precise positioning of the osteotomy site (the bone surface around the cutting line, the “H” point of the proximal tibia, the internal and external malleolus fixators, etc.) and the correction angle (the pre-drilled holes, the wedge-shaped filling blocks, the angle-guided connecting rod, etc.) during operation, and all of them achieve good effectiveness. ConclusionCompared with conventional OWHTO, 3D printing PSCG assisted OWHTO has many obvious advantages, such as shortening the operation time, and the frequency of fluoroscopy, and being closer to the expected preoperative correction, etc. However, the effectiveness between different 3D printing PSCGs still need to be discussed in the follow-up studies.
Objective To investigate the effectiveness of using 3 hollow compression screws combined with 1 screw off-axis fixation under the guidance of three-dimensional (3D) printed guide plate with mortise-tenon joint structure (mortise-tenon joint plate) for the treatment of Pauwels type Ⅲ femoral neck fractures. Methods A clinical data of 78 patients with Pauwels type Ⅲ femoral neck fractures, who were admitted between August 2022 and August 2023 and met the selection criteria, was retrospectively analyzed. The operations were assisted with mortise-tenon joint plates in 26 cases (mortise-tenon joint plate group) and traditional guide plates in 28 cases (traditional plate group), and without guide plates in 24 cases (control group). There was no significant difference in the baseline data of gender, age, body mass index, cause of injury, and fracture side between groups (P>0.05). The operation time, intraoperative blood loss, frequency of intraoperative fluoroscopy, incision length, incidence of postoperative deep vein thrombosis of lower extremity, pain visual analogue scale (VAS) score at 1 week after operation, and Harris score of hip joint at 3 months after operation were recorded and compared. X-ray re-examination was taken to check the quality of fracture reduction, fracture healing, and the shortening length of the femoral neck at 3 months after operation, and the incidences of internal fixation failure and osteonecrosis of the femoral head during operation. Results Compared with the control group, the operation time, intraoperative blood loss, and frequency of intraoperative fluoroscopy reduced in the two plate groups, and the quality of fracture reduction was better, but the incision was longer, and the differences were significant (P<0.05). The operation time and intraoperative blood loss were significantly higher in the traditional plate group than in the mortise-tenon joint plate group (P<0.05), the incision was significantly longer (P<0.05); and the difference in fracture reduction quality and the frequency of intraoperative fluoroscopy was not significant between two plate groups (P>0.05). There was 1 case of deep vein thrombosis of lower extremity in the traditional plate group and 1 case in the control group, while there was no thrombosis in the mortise-tenon joint plate group. There was no significant difference in the incidence between groups (P>0.05). All patients were followed up 12-15 months (mean, 13 months). There was no significant difference in VAS score at 1 week and Harris score at 3 months between groups (P>0.05). Compared with the control group, the fracture healing time and the length of femoral neck shortening at 3 months after operation were significantly shorter in the two plate groups (P<0.05). There was no significant difference between the two plate groups (P>0.05). There was no significant difference in the incidences of non-union fractures, osteonecrosis of the femoral head, or internal fixation failure between groups (P>0.05). Conclusion For Pauwels type Ⅲ femoral neck fractures, the use of 3D printed guide plate assisted reduction and fixation can shorten the fracture healing time, reduce the incidence of postoperative complications, and be more conducive to the early functional exercise of the affected limb. Compared with the traditional guide plate, the mortise-tenon joint plate can reduce the intraoperative bleeding and shorten the operation time.
Objective To evaluate the safety and effectiveness of applying self-stabilizing zero-profile three-dimensional (3D) printed artificial vertebral bodies in anterior cervical corpectomy and fusion (ACCF) for cervical spondylotic myelopathy. Methods A retrospective analysis was conducted on 37 patients diagnosed with cervical spondylotic myelopathy who underwent single-level ACCF using either self-stabilizing zero-profile 3D-printed artificial vertebral bodies (n=15, treatment group) or conventional 3D-printed artificial vertebral bodies with titanium plates (n=22, control group) between January 2022 and February 2023. There was no significant difference in age, gender, lesion segment, disease duration, and preoperative Japanese Orthopedic Association (JOA) score between the two groups (P>0.05). Operation time, intraoperative bleeding volume, hospitalization costs, JOA score and improvement rate, incidence of postoperative prosthesis subsidence, and interbody fusion were recorded and compared between the two groups. Results Compared with the control group, the treatment group had significantly shorter operation time and lower hospitalization costs (P<0.05); there was no significant difference in intraoperative bleeding volume between the two groups (P>0.05). All patients were followed up, with a follow-up period of 6-21 months in the treatment group (mean, 13.7 months) and 6-19 months in the control group (mean, 12.7 months). No dysphagia occurred in the treatment group, while 5 cases occurred in the control group, with a significant difference in the incidence of dysphagia between the two groups (P<0.05). At 12 months after operation, both groups showed improvement in JOA scores compared to preoperative scores, with significant differences (P<0.05); however, there was no significant difference in the JOA scores and improvement rate between the two groups (P>0.05). Radiographic examinations showed the interbody fusion in both groups, and the difference in the time of interbody fusion was not significant (P>0.05). At last follow-up, 2 cases in the treatment group and 3 cases in the control group experienced prosthesis subsidence, with no significant difference in the incidence of prosthesis subsidence (P>0.05). There was no implant displacement or plate-screw fracture during follow-up.Conclusion The use of self-stabilizing zero-profile 3D-printed artificial vertebral bodies in the treatment of cervical spondylotic myelopathy not only achieves similar effectiveness to 3D-printed artificial vertebral bodies, but also reduces operation time and the incidence of postoperative dysphagia.
ObjectiveTo determine the feasibility of fabricating molds using a three-dimensional (3D) printer for producing customized bone cement for repairing bone defect. MethodsBetween February 2015 and March 2016, 13 patients with bone defects were treated. There were 9 males and 4 females with an average age of 38.4 years (range, 20-58 years), including 7 cases of chronic osteomyelitis, 3 cases of bone tuberculosis, 2 cases of bone tumor, and 1 case of ischemic necrosis. The defect located at the humerus in 3 cases, at the femur in 4 cases, and at the tibia in 6 cases. The defect ranged from 4.5 to 8.9 cm in length (mean, 6.7 cm). Before operation, Mimics10.01 software was used to design cement prosthesis, 3-matic software to design shaping module which was printed by 3D technology. After removal of the lesion bone during operation, bone cement was filled into the shaping module to prepare bone cement prosthesis for repairing defect. ResultsThe measurement result from Image J software showed that the match index of interface between the mirror restored digital and bone interface was 95.1%-97.4% (mean, 96.3%); the match index of interface between bone cement prosthesis and bone interface was 91.2%-94.7% (mean, 93.2%). It was one time success during separation between formed bone cement and shaping module without any shatter or fall off. All incisions healed by first intention. The cases were followed up 5-17 months (mean, 9.4 months). X-ray films and CT scans showed good position of bone cement prosthesis without any fracture; no peripheral fracture occurred. Conclusion3D printing customized bone cement shaping module can shorten the operation time, and customized bone cement prothesis has good match with bone interface, so it can avoid further adjustment and accord with the biomechanical rules of surgical site.
ObjectiveTo construct large block of engineered liver tissue by co-culture of fibroblasts and hepatocytes on collagen hydrogels in vitro and do in vivo implantation research. MethodsSilastic mould was prepared using three-dimensional printing technology. The collagen hydrogel scaffold was prepared by collagen hydrogel gel in the silicone mould and was removed. Sprague Dawley rat lung fibroblasts were co-cultured with primary hepatocytes at a ratio of 0.4:1 on the collagen hydrogel scaffold to construct large block of engineered liver tissue in vitro (group B), and primary hepatocytes cultured on the collagen hydrogel scaffold served as control group (group A). The cell morphology was observed, and the liver function was tested at 1, 3, 7, 14, and 21 days after culture. The rat model (n=24) of hepatic cirrhosis was made by subcutaneous injection of carbon tetrachloride. And in vivo implantation study was carried in cirrhosis rat model. The phenotypic characteristics and functional expression of hepatocytes were evaluated at 3, 7, 14, 21, and 28 days after implantation. ResultsIn vitro results indicated that hepatocytes in group B exhibited compact polyhedral cells with round nuclei and high expression of liver function. Moreover, cells aggregated to the most at 7 days. Album production and urea synthesis incresed significantly when compared with group A (P<0.05). In vivo results showed hepatocytes in group B survived for 28 days, and albumin production and urea synthesis were significantly increased. In addition, hepatocytes showed an aggregated distribution and cord-like structures, which was similar to normal liver tissue. ConclusionThe large block of engineered liver tissue constructed by co-cultured cells can form tissue similar to normal liver tissue in vivo, and survive for a long time, laying foundations for building more complete engineered liver tissue in the future.
ObjectiveTo explore the effectiveness of excision and reconstruction of bone tumor by using operation guide plate made by variety of three-dimensional (3-D) printing techniques, and to compare the advantages and disadvantages of different 3-D printing techniques in the manufacture and application of operation guide plate. MethodsBetween September 2012 and January 2014, 31 patients with bone tumor underwent excision and reconstruction of bone tumor by using operation guide plate. There were 19 males and 12 females, aged 6-67 years (median, 23 years). The disease duration ranged from 15 days to 12 months (median, 2 months). There were 13 cases of malignant tumor and 18 cases of benign tumor. The tumor located in the femur (9 cases), the spine (7 cases), the tibia (6 cases), the pelvis (5 cases), the humerus (3 cases), and the fibula (1 case). Four kinds of 3-D printing technique were used in processing operation guide plate:fused deposition modeling (FDM) in 9 cases, stereo lithography appearance (SLA) in 14 cases, 3-D printing technique in 5 cases, and selective laser sintering (SLS) in 3 cases; the materials included ABS resin, photosensitive resin, plaster, and aluminum alloy, respectively. Before operation, all patients underwent thin layer CT scanning (0.625 mm) in addition to conventional imaging. The data were collected for tumor resection design, and operation guide plate was designed on the basis of excision plan. Preoperatively, the operation guide plates were made by 3-D printing equipment. After sterilization, the guide plates were used for excision and reconstruction of bone tumor. The time of plates processing cycle was recorded to analyse the efficiency of 4 kinds of 3-D printing techniques. The time for design and operation and intraoperative fluoroscopy frequency were recorded. Twenty-eight patients underwent similar operations during the same period as the control group. ResultsThe processing time of operation guide plate was (19.3±6.5) hours in FDM, (5.2±1.3) hours in SLA, (8.6±1.9) hours in 3-D printing technique, and (51.7±12.9) hours in SLS. The preoperative design and operation guide plate were successfully made, which was used for excision and reconstruction of bone tumor in 31 cases. Except 3 failures (operation guide plate fracture), the resection and reconstruction operations followed the preoperative design in the other 28 cases. The patients had longer design time, shorter operation time, and less fluoroscopy frequency than the patients of the control group, showing significant differences (P<0.05). The follow-up time was 1-12 months (mean, 3.7 months). Postoperative X-ray and CT showed complete tumor resection and stable reconstruction. Conclusion3-D printing operation guide plates are well adapted to the requirements of individual operation for bone tumor resection and reconstruction. The 4 kinds of 3-D printing techniques have their own advantages and should be chosen according to the need of operation.