Objective
To review the current research progress of three-dimensional (3-D) printing technique in foot and ankle surgery.
Methods
Recent literature associated with the clinical application of 3-D printing technique in the field of medicine, especially in foot and ankle surgery was reviewed, summarized, and analyzed.
Results
At present, 3-D printing technique has been applied in foot and ankle fracture, segmental bone defect, orthosis, corrective surgery, reparative and reconstructive surgery which showed satisfactory effectiveness. Currently, there are no randomized controlled trials and the medium to long term follow-up is necessary.
Conclusion
The printing materials, time, cost, medical ethics, and multi-disciplinary team restricted the application of 3-D printing technique, but it is still a promising technique in foot and ankle surgery.
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.
ObjectiveTo review the current research status of in situ three-dimensional (3-D) printing technique and future trends.
MethodsRecent related literature about in situ 3-D printing technique was summarized, reviewed, and analyzed.
ResultsBased on the cl inical need for surgical repair, in situ 3-D printing technique is in the preliminary study, mainly focuses on in situ dermal repair and bone and cartilage repair, and succeeds in experiments, but there are still a lot of problems for cl inical application.
ConclusionWith the development of in situ 3-D printing technique, it will provide patients with real-time and in situ digital design and 3-D printing treatment with a timely and minimally invasive surgical repair process. It will be widely used in the future.
ObjectiveTo solve the fixation problem between ligament grafts and host bones in ligament reconstruction surgery by using ligament-bone composite scaffolds to repair the ligaments, to explore the fabrication method for ligament-bone composite scaffolds based on three-dimensional (3-D) printing technique, and to investigate their mechanical and biological properties in animal experiments.
MethodsThe model of bone scaffolds was designed using CAD software, and the corresponding negative mould was created by boolean operation. 3-D printing techinique was employed to fabricate resin mold. Ceramic bone scaffolds were obtained by casting the ceramic slurry in the resin mould and sintering the dried ceramics-resin composites. Ligament scaffolds were obtained by weaving degummed silk fibers, and then assembled with bone scaffolds and bone anchors. The resultant ligament-bone composite scaffolds were implanted into 10 porcine left anterior cruciate ligament rupture models at the age of 4 months. Mechanical testing and histological examination were performed at 3 months postoperatively, and natural anterior cruciate ligaments of the right sides served as control.
ResultsBiomechanical testing showed that the natural anterior cruciate ligament of control group can withstand maximum tensile force of (1 384±181) N and dynamic creep of (0.74±0.21) mm, while the regenerated ligament-bone scaffolds of experimental group can withstand maximum tensile force of (370±103) N and dynamic creep of (1.48±0.49) mm, showing significant differences (t=11.617,P=0.000; t=-2.991,P=0.020). In experimental group, histological examination showed that new bone formed in bone scaffolds. A hierarchical transition structure regenerated between ligament-bone scaffolds and the host bones, which was similar to the structural organizations of natural ligament-bone interface.
ConclusionLigament-bone composite scaffolds based on 3-D printing technique facilitates the regeneration of biomimetic ligament-bone interface. It is expected to achieve physical fixation between ligament grafts and host bone.
Objective A prospective study was conducted to investigate the feasibility and effectiveness of three-dimensional printed in vitro guide plates assisted hip arthroscopy in the treatment of Cam-type femoroacetabular impingement (FAI). Methods The clinical data of 25 patients with Cam-type FAI who met the selection criteria between December 2016 and September 2022 were collected. There were 13 males and 12 females with an average age of 42 years (range, 19-66 years). The disease duration ranged from 3 to 120 months, with an average of 22.2 months. The preoperative range of internal rotation-external rotation was (28.70±4.50)°, α angle was (69.04±0.99)°, visual analogue scale (VAS) score was 6.5±0.2, and modified Harris hip score (HHS) was 50.5±0.7. All patients were treated with hip arthroscopy assisted by three-dimensional printed in vitro guide plate. The occurrence of complications was observed postoperatively, α angle of the affected hip joint was measured on Dunn X-ray film, and the glenoid labrum injury was observed by MRI. The percentage of overlap between the Cam plasty area and the preoperative simulated grinding area was calculated by three-dimensional CT+reconstruction. The effectiveness was evaluated by VAS score and modified HHS score. ResultsPostoperative dorsalis pedis numbness occurred in 1 case, and the symptoms disappeared after 1 month of conventional drug treatment such as neurotrophy. Two cases of perineal skin injury occurred, and healed after symptomatic treatment. There was no male erectile dysfunction, deep incision infection, pulmonary embolism, or other serious complications occurred. The percentage of overlap between the Cam plasty area and the preoperative simulated grinding area was 81.6%-95.3%, with an average of 89.8%. All 25 patients were followed up 6-12 months, with an average of 8 months. At last follow-up, the range of internal rotation-external rotation was (40.10±2.98)°, α angle was (43.72±0.84)°, VAS score was 1.8±0.2, and the modified HHS score was 72.1±1.3, which significantly improved when compared with preoperative ones (P<0.05). ConclusionThe treatment of Cam-type FAI with three-dimensional printed in vitro guide plates assisted hip arthroscopy is safe and feasible, and can achieve good effectiveness.
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 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.
ObjectiveTo review the current progress of three-dimensional (3-D) printing technique in the clinical practice, its limitations and prospects.
MethodsThe recent publications associated with the clinical application of 3-D printing technique in the field of surgery, especially in orthopaedics were extensively reviewed.
ResultsCurrently, 3-D printing technique has been applied in orthopaedic surgery to aid diagnosis, make operative plans, and produce personalized prosthesis or implants.
Conclusion3-D printing technique is a promising technique in clinical application.
ObjectiveTo improve the poor mechanical strength of porous ceramic scaffold, an integrated method based on three-dimensional (3-D) printing technique is developed to incorporate the controlled double-channel porous structure into the polylactic acid/β-tricalcium phosphate (PLA/β-TCP) reinforced composite scaffolds (double-channel composite scaffold) to improve their tissue regeneration capability and the mechanical properties.
MethodsThe designed double-channel structure inside the ceramic scaffold consisted of both primary and secondary micropipes, which parallel but un-connected. The set of primary channels was used for cell ingrowth, while the set of secondary channels was used for the PLA perfusion. Integration technology of 3-D printing technique and gel-casting was firstly used to fabricate the double-channel ceramic scaffolds. PLA/β-TCP composite scaffolds were obtained by the polymer gravity perfusion process to pour PLA solution into the double-channel ceramic scaffolds through the secondary channel set. Microscope, porosity, and mechanical experiments for the standard samples were used to evaluate the composite properties. The ceramic scaffold with only the primary channel (single-channel scaffold) was also prepared as a control.
ResultsMorphology observation results showed that there was no PLA inside the primary channels of the double-channel composite scaffolds but a dense interface layer between PLA and β-TCP obviously formed on the inner wall of the secondary channels by the PLA penetration during the perfusion process. Finite element simulation found that the compressive strength of the double-channel composite scaffold was less than that of the single-channel scaffold; however, mechanical tests found that the maximum compressive strength of the double-channel composite scaffold[(21.25±1.15) MPa] was higher than that of the single-channel scaffold[(9.76±0.64) MPa].
ConclusionThe double-channel composite scaffolds fabricated by 3-D printing technique have controlled complex micropipes and can significantly enhance mechanical properties, which is a promising strategy to solve the contradiction of strength and high-porosity of the ceramic scaffolds for the bone tissue engineering application.
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.
