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 evaluate the effectiveness of total knee arthroplasty (TKA) using three-dimensional (3D) printing technology for knee osteoarthritis (KOA) accompanied with extra-articular deformity. Methods Between March 2013 and December 2015, 15 patients (18 knees) with extra-articular deformity and KOA underwent TKA. There were 6 males (6 knees) and 9 females (12 knees), aged 55-70 years (mean, 60.2 years). The mean disease duration was 10.8 years (range, 7-15 years). The unilateral knee was involved in 12 cases and bilateral knees in 3 cases. The clinical score was 57.44±1.06 and the functional score was 60.88±1.26 of Knee Society Score (KSS). The range of motion of the knee joint was (72.22±0.18)°. The deviation of mechanical axis of lower limb was (18.89±0.92)° preoperatively. There were 8 cases (10 knees) with extra-articular femoral deformity, 5 cases (5 knees) with extra-articular tibial deformity, and 2 cases (3 knees) with extra-articular femoral and tibial deformities. Bone models and the navigation templates were printed and the operation plans were designed using 3D printing technology. The right knee joint prostheses were chosen. Results The operation time was 65-100 minutes (mean, 75.6 minutes). The bleeding volume was 50-150 mL (mean, 90.2 mL). There was no poor incision healing, infection, or deep venous thrombosis after operation. All patients were followed up 12- 30 months (mean, 22 months). Prostheses were located in the right place, and no sign of loosening or subsidence was observed by X-ray examination. At last follow-up, the deviation of mechanical axis of lower limb was (2.00±0.29)°, showing significant difference when compared with preoperative one (t=13.120, P=0.007). The KSS clinical score was 87.50±0.88 and function score was 81.94±1.41, showing significant differences when compared with preoperative ones (t=27.553, P=0.000; t=35.551, P=0.000). The range of motion of knee was (101.94±1.42)°, showing significant difference when compared with preoperative one (t=31.633, P=0.000). Conclusion For KOA accompanied with extra-articular deformity, TKA using 3D printing technology has advantages such as individualized treatment, reducing the difficulty of operation, and achieving the satisfactory function.
ObjectiveTo explore the feasibility of the repair and reconstruction of large talar lesions with three-dimensional (3D) printed talar components by biomechanical test.MethodsSix cadaveric ankle specimens were used in this study and taken CT scan and reconstruction. Then, 3D printed talar component and osteotomy guide plate were designed and made. After the specimen was fixed on an Instron mechanical testing machine, a vertical pressure of 1 500 N was applied to the ankle when it was in different positions (neutral, 10° of dorsiflexion, and 14° of plantar flexion). The pressure-bearing area and pressure were measured and calculated. Then osteotomy on specimen was performed and 3D printed talar components were implanted. And the biomechanical test was performed again to compare the changes in pressure-bearing area and pressure.ResultsBefore the talar component implantation, the pressure-bearing area of the talus varied with the ankle position in the following order: 10° of dorsiflexion > neutral position > 14° of plantar flexion, showing significant differences between positions ( P<0.05). The pressure exerted on the talus varied in the following order: 10° of dorsiflexion < neutral position < 14° of plantar flexion, showing significant differences between positions (P<0.05). The pressure-bearing area and pressure were not significantly different between before and after talar component implantations in the same position (P>0.05). The pressure on the 3D printed talar component was not significantly different from the overall pressure on the talus (P>0.05).ConclusionApplication of the 3D printed talar component can achieve precise repair and reconstruction of the large talar lesion. The pressure on the repaired site don’t change after operation, indicating the clinical feasibility of this approach.
ObjectiveTo study the effect of three-dimensional (3D) printed β-tricalcium phosphate (β-TCP) scaffold loaded poly (lactide-co-glycolide) (PLGA) anti-tuberculosis drug sustained release microspheres on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and its cytotoxicity.MethodsIsoniazid and rifampicin/PLGA sustained release microspheres were prepared by W/O/W multiple emulsion method. The β-TCP scaffolds were prepared by 3D printing technique. The microspheres were loaded on the scaffolds by centrifugal oscillation method to prepare composite materials. The BMSCs of Sprague Dawley rat were isolated and cultured by whole bone marrow adherent method, and the third generation cells were used for the following experiments. BMSCs were co-cultured with osteogenic induction medium (group A), PLGA anti-tuberculosis drug sustained release microsphere extract (group B), 3D printed β-TCP scaffold extract (group C), and 3D printed β-TCP scaffold loaded PLGA anti-tuberculosis drug sustained release microsphere composite extract (group D), respectively. Cytotoxicity was detected by cell counting kit 8 (CCK-8) method; the calcium deposition was observed by alizarin red staining; and the mRNA expressions of alkaline phosphatase (ALP), osteocalcin (OCN), and bone sialoprotein (BSP) were detected by real-time fluorescence quantitative PCR (RT-qPCR).ResultsCCK-8 assay showed that the absorbance (A) value of groups A, B, C, and D increased gradually with the culture time prolonging. After cultured for 24, 48, and 72 hours, the A value decreased in the order of groups A, C, B, and D. There was no significant difference between groups B and D (P>0.05), but there were significant differences between other groups (P<0.05). The cytotoxicity was evaluated as grade 0-2, and the toxicity test was qualified. Alizarin red staining showed that red mineralized nodules were formed in all groups at 21 days after osteogenic induction, but the number of mineralized nodules decreased sequentially in groups C, D, A, and B. RT-qPCR test results showed that the relative expressions of OCN and BSP genes in groups A, B, C, and D increased gradually with the culture time prolonging. The relative expression of ALP gene increased at 7 and 14 days, and decreased at 21 days. After cultured for 7, 14, and 21 days, the relative expressions of ALP, OCN, and BSP genes decreased sequentially in groups C, D, A, and B; the differences were significant between groups at different time points (P<0.05).Conclusion3D printed β-TCP loaded PLGA anti-tuberculosis drug sustained release microsphere composites have no obvious cytotoxicity to BMSCs, and can promote BMSCs to differentiate into osteoblasts to a certain extent.
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.
ObjectiveTo evaluate the effectiveness of high tibial osteotomy (HTO) assisted by three-dimensional (3-D) printing technology for correction of varus knee with osteoarthritis. MethodBetween January 2014 and June 2015, 16 patients (20 knees) with varus knee and osteoarthritis underwent HTO assisted by 3-D printing technology; a locking compression plate was used for internal fixation after HTO. There were 6 males and 10 females, aged 30-60 years (mean, 45.5 years). The disease duration was 1-10 years (mean, 6.2 years). The unilateral knee was involved in 12 cases and bilateral knees in 4 cases. According to Koshino's staging system, 3 knees were classified as stage I, 7 knees as stage Ⅱ, 8 knees as stage Ⅲ, and 2 knees as stage IV. Preoperative Hospital for Special Surgery (HSS) knee score was 63.8±2.2; the femorotibial angle was (184.8±2.9) °; and Insall-Salvati index was 1.03±0.13. ResultsAll the wounds healed primarily, and no complication of infection, osteofacial compartment syndrom, or deep vein thrombosis was observed. All patients were followed up 6-18 months (mean, 12.6 months). Personal paralysis was observed in 1 case (1 knee), and was cured after expectant treatment. Bone union time was 2.7-3.4 months (mean, 2.9 months). At 6 months after operation, the femorotibial angle was (173.8±2.0) °, showing significant difference when compared with preoperative one (t=11.70, P=0.00) ; Insall-Salvati index was 1.04±0.12, showing no significant difference when compared with preoperative one (t=-0.20, P=0.85) ; and HSS knee score was significantly increased to 88.9±3.1 (t=-25.44, P=0.00) . At last follow-up, the results were excellent in 13 knees, good in 6 knees, fair in 1 knee, and the excellent and good rate was 95%. Conclusions3-D printing cutting block can greatly improve the accuracy of HTO, avoid repeated X-ray and multiple osteotomy, shorten the operation time, and ensure better effectiveness for correction of varus knee with osteoarthritis.
ObjectiveTo investigate the effect of three-dimensional (3D) printing guide plate on improving femoral rotational alignment and patellar tracking in total knee arthroplasty (TKA).MethodsBetween January 2018 and October 2018, 60 patients (60 knees) with advanced knee osteoarthritis who received TKA and met the selection criteria were selected as the study subjects. Patients were randomly divided into two groups according to the random number table method, with 30 patients in each group. The TKA was done with the help of 3D printing guide plate in the guide group and following traditional procedure in the control group. There was no significant difference in gender, age, disease duration, side, and preoperative hip-knee-ankle angle (HKA), posterior condylar angle (PCA), patella transverse axis-femoral transepicondylar axis angle (PFA), Hospital for Special Surgery (HSS) score, and American Knee Society (AKS) score (P>0.05).ResultsAll incisions healed by first intention and no complications related to the operation occurred. All patients were followed up 10-12 months, with an average of 11 months. HSS score and AKS score of the two groups at 6 months after operation were significantly higher than those before operation (P<0.05), but there was no significant difference between the two groups (P>0.05). Postoperative X-ray films showed that the prosthesis was in good position, and no prosthesis loosening or sinking occurred during follow-up. HKA, PCA, and PFA significantly improved in the two groups at 10 months after operation compared with those before operation (P<0.05). There was no significant difference in HKA at 10 months between the two groups (t=1.031, P=0.307). PCA and PFA in the guide group were smaller than those in the control group (P<0.05).ConclusionApplication of 3D printing guide plate in TKA can not only correct the deformity of the knee joint and alleviate the pain symptoms, but also achieve the goal of the accurate femoral rotation alignment and good patellar tracking.
ObjectiveTo explore the application of three-dimensional (3-D) printing technique in repair and reconstruction of maxillofacial bone defect. MethodsThe related literature on the recent advance in the application of 3-D printing technique for repair and reconstructing maxillofacial bone defect was reviewed and summarized in the following aspects:3-D models for teaching, preoperative planning, and practicing; surgical templates for accurate positioning during operation; individual implantable prosthetics for repair and reconstructing the maxillofacial bone defect. Results3-D printing technique is profoundly affecting the treatment level in repair and reconstruction of maxillofacial bone defect. Conclusion3-D printing technique will promote the development of the repair and reconstructing maxillofacial bone defect toward more accurate, personalized, and safer surgery.
ObjectiveTo investigate the effectiveness of digital three-dimensional (3D) printing osteotomy guide plate assisted total knee arthroplasty (TKA) in treatment of knee osteoarthritis (KOA) patients with femoral internal implants. Methods The clinical data of 55 KOA patients who met the selection criteria between July 2021 and October 2023 were retrospectively analyzed. Among them, 26 cases combined with femoral implants were treated with digital 3D printing osteotomy guide plate assisted TKA (guide plate group), and 29 cases were treated with conventional TKA (control group). There was no significant difference in gender, age, body mass index, side, Kellgren-Lawrence classification, preoperative visual analogue scale (VAS) score, Hospital for Special Surgery (HSS) knee score, knee range of motion, and other baseline data between the two groups (P>0.05). The operation time, intraoperative blood loss, incision length, postoperative first ambulation time, surgical complications; VAS score, knee HSS score, knee range of motion before operation, at 1 week and 3 months after operation, and at last follow-up; distal femoral lateral angle, proximal tibial medial angle, hip-knee-ankle angle and other imaging indicators at last follow-up were recorded and compared between the two groups. ResultsThe operation time, incision length, intraoperative blood loss, and postoperative first ambulation time in the guide plate group were significantly lower than those in the control group (P<0.05). In the control group, there were 1 case of incision rupture and bleeding and 1 case of lower limb intermuscular venous thrombosis, which was cured after symptomatic treatment. There was no complication such as neurovascular injury, incision infection, or knee prosthesis loosening in both groups. Patients in both groups were followed up 12-26 months, with an average of 16.25 months. The VAS score, HSS score, and knee range of motion improved at each time point after operation in both groups, and further improved with time after operation, the differences were significant (P<0.05). The above indicators in the guide plate group were significantly better than those in the control group at 1 week and 3 months after operation (P<0.05), and there was no significant difference between the two groups at last follow-up (P>0.05). At last follow-up, the distal femoral lateral angle, the proximal tibial medial angle, and the hip-knee-ankle angle in the guide plate group were significantly better than those in the control group (P<0.05). Conclusion The application of digital 3D printing osteotomy guide plate assisted TKA in the treatment of KOA patients with femoral implants can simplify the surgical procedures, overcome limitations of conventional osteotomy guides, reduce surgical trauma, achieve individualized and precise osteotomy, and effectively restore lower limb alignment and knee joint function.
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.