ObjectiveTo manufacture a polycaprolactone (PCL)/type Ⅰ collagen (COL Ⅰ) tissue engineered meniscus scaffold (hereinafter referred to as PCL/COL Ⅰ meniscus scaffold) by three-dimensional (3D) printing with low temperature deposition technique and to study its physicochemical properties.MethodsFirst, the 15% PCL/4% COLⅠ composite solution and 15% PCL simple solution were prepared. Then, 15% PCL/4% COL Ⅰmeniscus scaffold and 15% PCL meniscal scaffold were prepared by using 3D printing with low temperature deposition techniques. The morphology and microstructure of the scaffolds were observed by gross observation and scanning electron microscope. The compression modulus and tensile modulus of the scaffolds were measured by biomechanical test. The components of the scaffolds were analyzed by Fourier transform infrared spectroscopy (FTIR). The contact angle of the scaffold surface was measured. The meniscus cells of rabbits were cultured with the two scaffold extracts and scaffolds, respectively. After cultured, the cell proliferations were detected by cell counting kit 8 (CCK-8), and the normal cultured cells were used as controls. Cell adhesion and growth of scaffold-cell complex were observed by scanning electron microscope.ResultsAccording to the gross and scanning electron microscope observations, two scaffolds had orientated 3D microstructures and pores, but the surface of the PCL/COLⅠ meniscus scaffold was rougher than the PCL meniscus scaffold. Biomechanical analysis showed that the tensile modulus and compression modulus of the PCL/COL Ⅰ meniscus scaffold were not significantly different from those of the PCL meniscus scaffold (P>0.05). FTIR analysis results showed that COL Ⅰ and PCL were successful mixed in PCL/ COL Ⅰ meniscus scaffolds. The contact angle of PCL/COLⅠ meniscus scaffold [(83.19±7.49)°] was significantly lower than that of PCL meniscus scaffold [(111.13±5.70)°] (t=6.638, P=0.000). The results of the CCK-8 assay indicated that with time, the number of cells cultured in two scaffold extracts showed an increasing trend, and there was no significant difference when compared with the control group (P>0.05). Scanning electron microscope observation showed that the cells attached on the PCL/ COL Ⅰ meniscus scaffold more than that on the PCL scaffold.ConclusionPCL/COLⅠmeniscus scaffolds are prepared by 3D printing with low temperature deposition technique, which has excellent physicochemical properties without cytotoxicity. PCL/COLⅠmeniscus scaffold is expected to be used as the material for meniscus tissue engineering.
With the development of three-dimensional (3D) printing technology, more and more researches have focused on its application in the region of intervertebral fusion materials; the prospects are worth looking forward to. This article reviews the researches about 3D printing technology in spinal implants, and summarizes the materials and printing technology applied in the field of spinal interbody fusion, and the shortcomings in the current research and application. With the rapid development of 3D printing technology and new materials, more and more 3D printing spinal interbodies will be developed and used clinically.
ObjectiveTo explore a method of three-dimensional (3D) printing technology for preparation of personalized rat brain tissue cavity scaffolds so as to lay the foundation for the repair of traumatic brain injury (TBI) with tissue engineered customized cavity scaffolds. MethodsFive male Sprague Dawley rats[weighing (300±10) g] were induced to TBI models by electric controlled cortical impactor. Mimics software was used to reconstruct the surface profile of the damaged cavity based on the MRI data, computer aided design to construct the internal structure. Then collagen-chitosan composite was prepared for 3D bioprinter of bionic brain cavity scaffold. ResultsMRI scans showed the changes of brain tissue injury in the injured side, and the position of the cavity was limited to the right side of the rat brain cortex. The 3D model of personalized cavity containing the internal structure was successfully constructed, and cavity scaffolds were prepared by 3D printing technology. The external contour of cavity scaffolds was similar to that of the injured zone in the rat TBI; the inner positive crossing structure arranged in order, and the pore connectivity was good. ConclusionCombined with 3D reconstruction based on MRI data, the appearance of cavity scaffolds by 3D printing technology is similar to that of injured cavity of rat brain tissue, and internal positive cross structure can simulate the topological structure of the extracellular matrix, and printing materials are collagen-chitosan complexes having good biocompatibility, so it will provide a new method for customized cavity scaffolds to repair brain tissue cavity after TBI.
Objective To summarize the application progress of three-dimensional (3D) printed metal prosthesis in joint surgery. Methods The related literature was extensively reviewed. The effectiveness of 3D printed metal prosthesis in treatment of joint surgery diseases were discussed and summarized, including the all key issues in prosthesis transplantation such as prosthesis stability, postoperative complications, bone ingrowth, etc. Results 3D printed metal prosthesis has good matching degree, can accurately reconstruct and restore joint function, reduce operation time, and achieve high patient satisfaction in short- and medium-term follow-up. Its application in joint surgery has made good progress. Conclusion The personalized microporous structure prostheses of different shapes produced by 3D printing can solve the problem of poor personalized matching of joints for special patients existing in traditional prostheses. Therefore, 3D printing technology is full of hope and will bring great potential to the reform of orthopedic practice in the future.
Objective To discuss the effect of three-dimensional (3D) printing individualized model and guide plate in bone tumor surgery. Methods Between October 2015 and December 2016, 3D printing individualized model and guide plate for making preoperative surgical planning and intraoperative treatment were used in 5 patients of bone tumor. All the patients were male, with a median age of 32 years (range, 9-58 years). There were 1 case of cystic echinococcosis at left pelvis and pathological fracture of the proximal femur; 1 case of left iliac bone osteoblastoma associated with aneurysmal bone cyst; 1 case of fibrous dysplasia of the left femur (sheep horn deformity) with pathological fracture; 1 case of metastatic carcinoma of right calcaneus (tumor staging was T2N0M0); and 1 case of Ewing sarcoma of left femur (tumor staging was T2N0M0). The disease duration ranged from 1 month to 10 years (mean, 2.25 years). Results The operation was completed successfully. The operation time was 2.6-7.5 hours (mean, 4.9 hours). The intraoperative blood loss was 200-2 500 mL (mean, 1 380 mL). The intraoperative fluoroscopy times was 1-6 times (mean, 3.8 times). There was no infection after operation, and the blood supply and nerve function were good. All the patients were followed up 3-16 months (mean, 5.4 months). No loosening or breaking of the internal fixator occurred. According to Enneking scoring system, the limb function score was 15-26 (mean, 21); and the results were excellent in 2 cases, good in 2 cases, and fair in 1 case. Conclusion 3D printing technology can make the implementation of the better preoperative planning and evaluation in bone tumor surgery, and it provides a new reference for individualized treatment in patients with bone tumor.
ObjectiveTo investigate whether subchondral bone microstructural parameters are related to cartilage repair during large osteochondral defect repairing based on three-dimensional (3-D) printing technique. MethodsBiomimetic biphasic osteochondral composite scaffolds were fabricated by using 3-D printing technique. The right trochlea critical sized defects (4.8 mm in diameter, 7.5 mm in depth) were created in 40 New Zealand white rabbits (aged 6 months, weighing 2.5-3.5 kg). Biomimetic biphasic osteochondral composite scaffolds were implanted into the defects in the experimental group (n=35), and no composite scaffolds implantation served as control group (n=5); the left side had no defect as sham-operation group. Animals of experimental and sham-operation groups were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after operation, while animals of control group were sampled at 24 weeks. Subchondral bone microstructural parameters and cartilage repair were quantitatively analyzed using Micro-CT and Wayne scoring system. Correlation analysis and regression analysis were applied to reveal the relationship between subchondral bone parameters and cartilage repair. The subchondral bone parameters included bone volume fraction (BV/TV), bone surface area fraction (BSA/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular spacing (Tb.Sp). ResultsIn the experimental group, articular cartilage repair was significantly improved at 52 weeks postoperatively, which was dominated by hyaline cartilage tissue, and tidal line formed. Wayne scores at 24 and 52 weeks were significantly higher than that at 16 weeks in the experimental group (P<0.05), but no significant difference was found between at 24 and 52 weeks (P>0.05); the scores of experimental group were significantly lower than those of sham-operation group at all time points (P<0.05). In the experimental group, new subchondral bone migrated from the surrounding defect to the centre, and subchondral bony plate formed at 24 and 52 weeks. The microstructural parameters of repaired subchondral bone followed a "twin peaks" like discipline to which BV/TV, BSA/BV, and Tb.N increased at 2 and 16 weeks, and then they returned to normal level. The Tb.Sp showed reversed discipline compared to the former 3 parameters, no significant change was found for Tb.Th during the repair process. Correlation analysis showed that BV/TV, BSA/BV, Tb.Th, Tb.N, and Tb.Sp were all related with gross appearance score and histology score of repaired cartilage. ConclusionSubchondral bone parameters are related with cartilage repair in critical size osteochondral repair in vivo. Microstructural parameters of repaired subchondral bone follow a "twin peaks" like discipline (osteoplasia-remodeling-osteoplasia-remodeling) to achieve reconstruction, 2nd week and 16th week are critical time points for subchondral bone functional restoration.
Objective To review the application progress of digital technology in auricle reconstruction. Methods The recently published literature concerning the application of digital technology in auricle reconstruction was extensively consulted, the main technology and its specific application areas were reviewed. Results Application of digital technology represented by three-dimensional (3D) data acquisition, 3D reconstruction, and 3D printing is an important developing trend of auricle reconstruction. It can precisely guide auricle reconstruction through fabricating digital ear model, auricular guide plate, and costal cartilage imaging. Conclusion Digital technology can improve effectiveness and decrease surgical trauma in auricle reconstruction. 3D bioprinting of ear cartilage future has bright prospect and needs to be further researched.
ObjectiveTo investigate the clinical application of three-dimensional (3D) printing technique combined with a new type of thoracic pedicle screw track detector in thoracic pedicle screw placement.MethodsAccording to the characteristics of thoracic pedicle and common clinical screw placement methods, a new type of thoracic pedicle screw track detector was independently developed and designed. The clinical data of 30 patients with thoracic vertebrae related diseases who underwent posterior thoracic pedicle screw fixation between March 2017 and January 2020 were retrospectively analysed. Among them, there were 18 males and 12 females with an average age of 56.3 years (range, 32-76 years). There was 1 case of thoracic disc herniation, 4 cases of thoracic canal stenosis, 2 cases of ossification of posterior longitudinal ligament of thoracic vertebra, 16 cases of thoracic trauma, 2 cases of thoracic infection, and 5 cases of thoracic canal occupation. Three-dimensional CT of the thoracic vertebra was routinely performed preoperatively, and the model of the patient’s thoracic vertebra was reconstructed and printed out. With the assistance of the model, preoperative simulation was performed with the combination of the new type thoracic pedicle screw track detector, and detected no nails after critical cortical damage. During operation, one side was randomly selected to use traditional hand screws placement (control group), and the other side was selected to use 3D printing technique combined with new type thoracic pedicle screw track detector to assist thoracic pedicle screws placement (observation group). The single screw placement time, adjustment times of single screw, and blood loss during screw placement were compared between the two groups. The accuracy of screw placement in the two groups was evaluated according to postoperative CT imaging data.ResultsThe single screw placement time, adjustment times of single screw, and blood loss during screw placement in the observation group were significantly less than those in the control group (P<0.05). Postoperative CT examination showed that the observation group had 87 screws of grade 1, 3 screws of grade 2, and the acceptable screw placement rate was 100% (90/90); the control group had 76 screws of grade 1, 2 screws of grade 2, 11 screws of grade 3, and 1 screw of grade 4, and the acceptable screw placement rate was 86.7% (78/90); showing significant difference in screw placement between the two groups (χ2=12.875, P=0.001). All patients were followed up 6-18 months, with an average of 11.3 months. There was no complication of vascular, nerve, spinal cord, or visceral injury, and screws or rods broken, and no patient was revised.ConclusionThe 3D printing technique combined with the new type of thoracic pedicle screw track detector assisted thoracic pedicle screw placement is convenient, and significantly improves the accuracy and safety of intraoperative screw placement, and overall success rate of the surgery.
With the developing of three-dimensional (3D) printing technology, it is widely used in the treatment of bone tumors in the clinical orthopedics. Because of the great individual differences in the location of bone tumor, resection and reconstruction are difficult. Based on 3D printing technology, the 3D models can be prepared to show the anatomical part of the disease, so that the surgeons can create a patient-specific operational plans based on better understand the local conditions. At the same time, preoperative simulation can also be carried out for complex operations and patient-specific prostheses can be further designed and prepared according to the location and size of tumor, which may have more advantages in adaptability. In this paper, the domestic and international research progress of 3D printing technology in the treatment of limb bone tumors in recent years were reviewed and summarized.
Objective To evaluate the effectiveness of three-dimensional (3-D) printing assisting minimally invasive for intraarticular calcaneal fractures with percutaneous poking reduction and cannulate screw fixation. Methods A retrospective analysis was performed of the 19 patients (19 feet) with intraarticular calcaneal fracture who had been treated between March 2015 and May 2016. There were 13 males and 6 females with an average age of 38.2 years (range, 24-73 years). There were 3 open fractures and 16 closed fractures. By Sanders classification, 12 cases were type Ⅱ, 7 cases were type Ⅲ. By Essex-Lopresti classification, 13 cases were tongue type, 6 cases were joint-depression type. The time from injury to surgery was 1-10 days (mean, 4.7 days). A thin slice CT scan was taken of bilateral calcaneus in patients. By using the mirror imaging technique, the contralateral mirror image and the affected side calcaneus model were printed according to 1∶1 ratio. The displacement of fracture block was observed and contrasted, and the poking reduction was simulated. Calcaneal fracture was treated by percutaneous minimally invasive poking reduction and cannulate screw fixation. The Böhler angle and Gissane angle at immediate after operation and last follow-up was measured on X-ray films, and compared with preoperative measurement. The functional recovery was evaluated by American Orthopaedic Foot and Ankle Society (AOFAS) scores. Results The operation time was 25-70 minutes (mean, 45 minutes). The intraoperative blood loss was 10-40 mL (mean, 14.5 mL). All the incisions healed by first intention and had no relevant postoperative complications such as skin necrosis, nail tract infection, and osteomyelitis. All the patients were followed up 12-25 months (mean, 14.6 months). All patients obtained fracture healing, and the fracture healing time was 8-14 weeks (mean, 10.3 weeks). No screw withdrawal or breakage occurred during follow-up; only 1 patient with Sanders type Ⅱ fracture, whose calcaneus height was partially lost at 6 weeks after operation, the other patients had no reduction loss and fracture displacement, and no traumatic arthritis occurred. The Böhler angle and Gissane angle at immediate after operation and last follow-up were significantly improved when compared with preoperative ones (P<0.05), but there was no significant difference between at immediate after operation and last follow-up (P>0.05). The AOFAS score was 76-100 (mean, 88.2), and the results were excellent in 10 feet, good in 7, and fair in 2, the excellent and good rate was 89.5%. Conclusion 3-D printing assisting minimally invasive for intraarticular calcaneal fractures with percutaneous poking reduction and cannulate screw fixation can reduce the surgical trauma, improve the quality of reduction and fixation, and make the operation more safe, accurate, and individualized.