bims-biprem Biomed News
on Bioprinting for regenerative medicine
Issue of 2024–04–21
sixteen papers selected by
Seerat Maqsood, University of Teramo



  1. Int J Biol Macromol. 2024 Apr 03. pii: S0141-8130(24)02086-5. [Epub ahead of print] 131281
      As an emerging new manufacturing technology, Three-dimensional (3D) bioprinting provides the potential for the biomimetic construction of multifaceted and intricate architectures of functional integument, particularly functional biomimetic dermal structures inclusive of cutaneous appendages. Although the tissue-engineered skin with complete biological activity and physiological functions is still cannot be manufactured, it is believed that with the advances in matrix materials, molding process, and biotechnology, a new generation of physiologically active skin will be born in the future. In pursuit of furnishing readers and researchers involved in relevant research to have a systematic and comprehensive understanding of 3D printed tissue-engineered skin, this paper furnishes an exegesis on the prevailing research landscape, formidable obstacles, and forthcoming trajectories within the sphere of tissue-engineered skin, including: (1) the prevalent biomaterials (collagen, chitosan, agarose, alginate, etc.) routinely employed in tissue-engineered skin, and a discerning analysis and comparison of their respective merits, demerits, and inherent characteristics; (2) the underlying principles and distinguishing attributes of various current printing methodologies utilized in tissue-engineered skin fabrication; (3) the present research status and progression in the realm of tissue-engineered biomimetic skin; (4) meticulous scrutiny and summation of the extant research underpinning tissue-engineered skin inform the identification of prevailing challenges and issues.
    Keywords:  3D bioprinting; Bioink; Tissue engineered skin
    DOI:  https://doi.org/10.1016/j.ijbiomac.2024.131281
  2. Prog Addit Manuf. 2022 Dec 27. 1-35
      The exponential rise of healthcare problems like human aging and road traffic accidents have developed an intrinsic challenge to biomedical sectors concerning the arrangement of patient-specific biomedical products. The additively manufactured implants and scaffolds have captured global attention over the last two decades concerning their printing quality and ease of manufacturing. However, the inherent challenges associated with additive manufacturing (AM) technologies, namely process selection, level of complexity, printing speed, resolution, biomaterial choice, and consumed energy, still pose several limitations on their use. Recently, the whole world has faced severe supply chain disruptions of personal protective equipment and basic medical facilities due to a respiratory disease known as the coronavirus (COVID-19). In this regard, local and global AM manufacturers have printed biomedical products to level the supply-demand equation. The potential of AM technologies for biomedical applications before, during, and post-COVID-19 pandemic alongwith its relation to the industry 4.0 (I4.0) concept is discussed herein. Moreover, additive manufacturing technologies are studied in this work concerning their working principle, classification, materials, processing variables, output responses, merits, challenges, and biomedical applications. Different factors affecting the sustainable performance in AM for biomedical applications are discussed with more focus on the comparative examination of consumed energy to determine which process is more sustainable. The recent advancements in the field like 4D printing and 5D printing are useful for the successful implementation of I4.0 to combat any future pandemic scenario. The potential of hybrid printing, multi-materials printing, and printing with smart materials, has been identified as hot research areas to produce scaffolds and implants in regenerative medicine, tissue engineering, and orthopedic implants.
    Keywords:  3D bioprinting; Additive manufacturing; Biomedical applications; COVID-19; Energy consumption; Implants; Industry 4.0; Tissue engineering
    DOI:  https://doi.org/10.1007/s40964-022-00373-9
  3. Diabetes Metab Syndr. 2024 Apr 10. pii: S1871-4021(24)00063-8. [Epub ahead of print]18(4): 103002
       AIMS: Despite numerous studies covering the various features of three-dimensional printing (3D printing) technology, and its applications in food science and disease treatment, no study has yet been conducted to investigate applying 3D printing in diabetes. Therefore, the present study centers on the utilization and impact of 3D printing technology in relation to the nutritional, pharmaceutical, and medicinal facets of diabetes management. It highlights the latest advancements, and challenges in this field.
    METHODS: In this review, the articles focusing on the application and effect of 3D printing technology on medical, pharmaceutical, and nutritional aspects of diabetes management were collected from different databases.
    RESULT: High precision of 3D printing in the placement of cells led to accurate anatomic control, and the possibility of bio-printing pancreas and β-cells. Transdermal drug delivery via 3D-printed microneedle (MN) patches was beneficial for the management of diabetes disease. 3D printing supported personalized medicine for Diabetes Mellitus (DM). For instance, it made it possible for pharmaceutical companies to manufacture unique doses of medications for every diabetic patient. Moreover, 3D printing allowed the food industry to produce high-fiber and sugar-free products for the individuals with DM.
    CONCLUSIONS: In summary, applying 3D printing technology for diabetes management is in its early stages, and needs to be matured and developed to be safely used for humans. However, its rapid progress in recent years showed a bright future for the treatment of diabetes.
    Keywords:  3D printer; Additive manufacturing; Nutrition; Personalized medicine; Pharmaceutics; diabetes
    DOI:  https://doi.org/10.1016/j.dsx.2024.103002
  4. Sci Technol Adv Mater. 2024 ;25(1): 2330339
      To successfully engineer large-sized tissues, establishing vascular structures is essential for providing oxygen, nutrients, growth factors and cells to prevent necrosis at the core of the tissue. The diameter scale of the biofabricated vasculatures should range from 100 to 1,000 µm to support the mm-size tissue while being controllably aligned and spaced within the diffusion limit of oxygen. In this review, insights regarding biofabrication considerations and techniques for engineered blood vessels will be presented. Initially, polymers of natural and synthetic origins can be selected, modified, and combined with each other to support maturation of vascular tissue while also being biocompatible. After they are shaped into scaffold structures by different fabrication techniques, surface properties such as physical topography, stiffness, and surface chemistry play a major role in the endothelialization process after transplantation. Furthermore, biological cues such as growth factors (GFs) and endothelial cells (ECs) can be incorporated into the fabricated structures. As variously reported, fabrication techniques, especially 3D printing by extrusion and 3D printing by photopolymerization, allow the construction of vessels at a high resolution with diameters in the desired range. Strategies to fabricate of stable tubular structures with defined channels will also be discussed. This paper provides an overview of the many advances in blood vessel engineering and combinations of different fabrication techniques up to the present time.
    Keywords:  3D printing; Blood vessel engineering; biofabrication; endothelialization; large-sized tissues
    DOI:  https://doi.org/10.1080/14686996.2024.2330339
  5. Biophys Rev (Melville). 2024 Jun;5(2): 021301
      Rapid advances in tissue engineering have resulted in more complex and physiologically relevant 3D in vitro tissue models with applications in fundamental biology and therapeutic development. However, the complexity provided by these models is often not leveraged fully due to the reductionist methods used to analyze them. Computational and mathematical models developed in the field of systems biology can address this issue. Yet, traditional systems biology has been mostly applied to simpler in vitro models with little physiological relevance and limited cellular complexity. Therefore, integrating these two inherently interdisciplinary fields can result in new insights and move both disciplines forward. In this review, we provide a systematic overview of how systems biology has been integrated with 3D in vitro tissue models and discuss key application areas where the synergies between both fields have led to important advances with potential translational impact. We then outline key directions for future research and discuss a framework for further integration between fields.
    DOI:  https://doi.org/10.1063/5.0179125
  6. ACS Biomater Sci Eng. 2024 Apr 15.
      Tissue engineering involves implanting grafts into damaged tissue sites to guide and stimulate the formation of new tissue, which is an important strategy in the field of tissue defect treatment. Scaffolds prepared in vitro meet this requirement and are able to provide a biochemical microenvironment for cell growth, adhesion, and tissue formation. Scaffolds made of piezoelectric materials can apply electrical stimulation to the tissue without an external power source, speeding up the tissue repair process. Among piezoelectric polymers, poly(vinylidene fluoride) (PVDF) and its copolymers have the largest piezoelectric coefficients and are widely used in biomedical fields, including implanted sensors, drug delivery, and tissue repair. This paper provides a comprehensive overview of PVDF and its copolymers and fillers for manufacturing scaffolds as well as the roles in improving piezoelectric output, bioactivity, and mechanical properties. Then, common fabrication methods are outlined such as 3D printing, electrospinning, solvent casting, and phase separation. In addition, the applications and mechanisms of scaffold-based PVDF in tissue engineering are introduced, such as bone, nerve, muscle, skin, and blood vessel. Finally, challenges, perspectives, and strategies of scaffold-based PVDF and its copolymers in the future are discussed.
    Keywords:  Electrical stimulation; Piezoelectricity; Polyvinylidene fluoride; Scaffold; Tissue engineering
    DOI:  https://doi.org/10.1021/acsbiomaterials.3c01989
  7. J Dent Sci. 2024 Apr;19(2): 1116-1125
       Background/purpose: 3D-printed bone tissue engineering is becoming recognized as a key approach in dentistry for creating customized bone regeneration treatments fitting patients bone defects requirements. 3D bioprinting offers an innovative method to fabricate detailed 3D structures, closely emulating the native bone micro-environment and better bone regeneration. This study aimed to develop an 3D-bioprintable scaffold using a combination of alginate and β-tricalcium phosphate (β-TCP) with the Cellink® BioX printer, aiming to advance the field of tissue engineering.
    Materials and methods: The physical and biological properties of the resulting 3D-printed scaffolds were evaluated at 10 %, 12 %, and 15 % alginate combined with 10 % β-TCP. The scaffolds were characterized through printability, swelling behavior, degradability, and element analysis. The biological assessment included cell viability, alkaline phosphatase (ALP) activity.
    Results: 10 % alginate/β-TCP 3D printed at 25 °C scaffold demonstrated the optimal condition for printability, swelling capability, and degradability of cell growth and nutrient diffusion. Addition of β-TCP particles significantly improved the 3D printed material viscosity over only alginate (P < 0.05). 10 % alginate/β-TCP enhanced MG-63 cell's proliferation (P < 0.05) and alkaline phosphatase activity (P < 0.001).
    Conclusion: This study demonstrated in vitro that 10 % alginate/β-TCP bioink characteristic for fabricating 3D acellular bioprinted scaffolds was the best approach. 10 % alginate/β-TCP bioink 3D-printed scaffold exhibited superior physical properties and promoted enhanced cell viability and alkaline phosphatase activity, showing great potential for personalized bone regeneration treatments.
    Keywords:  Alginate; Beta-tricalcium phosphate (β-TCP); Bioprinting; Bone regeneration
    DOI:  https://doi.org/10.1016/j.jds.2023.12.023
  8. Histol Histopathol. 2024 Apr 05. 18743
       BACKGROUND: Knee osteoarthritis (KOA) is a common chronic degenerative joint disease. 3D printing technology has become one of the important directions of medical development along with individualized precision treatment in orthopedics.
    OBJECTIVE: To investigate the effect of 3D printing technology-assisted total knee arthroplasty (TKA) on cartilage in rabbits with KOA.
    METHODS: A rabbit model of KOA was established and treated by TKA or 3D printing-assisted TKA. Four weeks after treatment, radiological evaluation of rabbit knees was performed by X-ray examination, in order to observe the severity of osteoarthritic lesions. Then the knee joints of rabbits were collected for Hematoxylin-eosin, Toluidine blue, and Safranin O-Fast green staining. The expressions of cartilage matrix metabolism-related and apoptosis-related genes were scrutinized by real-time quantitative reverse transcription-polymerase chain reaction, Western blot, and immunohistochemistry. The levels of inflammatory-related factors in the cartilage tissues of rabbits were tested by enzyme-linked immunosorbent assay.
    RESULTS: In rabbits with KOA, 3D printing technology-assisted TKA alleviated the inflammation and bone remodeling of the knee joint, relieved synovial hyperplasia and inflammatory cell infiltration in the articular cartilage, reduced articular cartilage degradation, suppressed cartilage matrix metabolism, and mitigated the inflammatory response and apoptosis of cartilage cells.
    CONCLUSION: 3D printing technology-assisted TKA exhibits a good treatment effect in rabbit KOA. This study provides an important basis for the clinical application of 3D printing technology-assisted TKA in KOA treatment.
    DOI:  https://doi.org/10.14670/HH-18-740
  9. Biomed Mater. 2024 Apr 16.
      Accurate segmentation of coronary artery tree and personalised 3D printing from medical images is essential for CAD diagnosis and treatment. The current literature on 3D printing relies solely on generic models created with different software or 3D coronary artery models manually segmented from medical images. Moreover, there are not many studies examining the bioprintability of a 3D model generated by artificial intelligence (AI) segmentation for complex and branched structures. In this study, deep learning algorithms with transfer learning have been employed for accurate segmentation of the coronary artery tree from medical images to generate printable segmentations. We propose a combination of deep learning and 3D printing, which accurately segments and prints complex vascular patterns in coronary arteries. Then, we performed the 3D printing of the AI-generated coronary artery segmentation for the fabrication of bifurcated hollow vascular structure. Our results indicate improved performance of segmentation with the aid of transfer learning with a Dice overlap score of 0.86 on a test set of 10 CTA images. Then, bifurcated regions from 3D models were printed into the Pluronic F-127 support bath using alginate+glucomannan hydrogel. We successfully fabricated the bifurcated coronary artery structures with high length and wall thickness accuracy, however, the outer diameters of the vessels and length of the bifurcation point differ from the 3D models. The extrusion of unnecessary material, primarily observed when the nozzle moves from left to the right vessel during 3D printing, can be mitigated by adjusting the nozzle speed. Moreover, the shape accuracy can also be improved by designing a multi-axis printhead that can change the printing angle in three dimensions. Thus, this study demonstrates the potential of the use of AI-segmented 3D models in the 3D printing of coronary artery structures and, when further improved, can be used for the fabrication of patient-specific vascular implants.
    Keywords:  3D printing; Coronary artery segmentation; Deep learning; Medical image processing; Support bath; hydrogel
    DOI:  https://doi.org/10.1088/1748-605X/ad3f60
  10. ACS Nano. 2024 Apr 17.
      Despite recent advances in the development of scaffold-based three-dimensional (3D) cell models, challenges persist in imaging and monitoring cell behavior within these complex structures due to their heterogeneous cell distribution and geometries. Incorporating sensors into 3D scaffolds provides a potential solution for real-time, in situ sensing and imaging of biological processes such as cell growth and disease development. We introduce a 3D printed hydrogel-based scaffold capable of supporting both surface-enhanced Raman scattering (SERS) biosensing and imaging of 3D breast cancer cell models. The scaffold incorporates plasmonic nanoparticles and SERS tags, for sensing and imaging, respectively. We demonstrate the scaffold's adaptability and modularity in supporting breast cancer spheroids, thereby enabling spatial and temporal monitoring of tumor evolution.
    Keywords:  3D cell models; 3D printing; SERS; bioimaging; biosensing; tumor microenvironment
    DOI:  https://doi.org/10.1021/acsnano.4c00543
  11. Int J Pharm. 2024 Apr 12. pii: S0378-5173(24)00348-X. [Epub ahead of print] 124114
      Personalized medicine aims to effectively and efficiently provide customized drugs that cater to diverse populations, which is a significant yet challenging task. Recently, the integration of artificial intelligence (AI) and three-dimensional (3D) printing technology has transformed the medical field, and was expected to facilitate the efficient design and development of customized drugs through the synergy of their respective advantages. In this study, we present an innovative method that combines AI and 3D printing technology to design and fabricate customized capsules. Initially, we discretized and encoded the geometry of the capsule, simulated the dissolution process of the capsule with classical drug dissolution model, and verified it by experiments. Subsequently, we employed a genetic algorithm to explore the capsule geometric structure space and generate a complex multi-layer structure that satisfies the target drug release profiles, including stepwise release and zero-order release. Finally, Two model drugs, isoniazid and acetaminophen, were selected and fused deposition modeling (FDM) 3D printing technology was utilized to precisely print the AI-designed capsule. The reliability of the method was verified by comparing the in vitro release curve of the printed capsules with the target curve, and the f2 value was more than 50. Notably, accurate and autonomous design of the drug release curve was achieved mainly by changing the geometry of the capsule. This approach is expected to be applied to different drug needs and facilitate the development of customized oral dosage forms.
    Keywords:  3D printing; Artificial intelligence; Customized capsules; Genetic algorithm
    DOI:  https://doi.org/10.1016/j.ijpharm.2024.124114
  12. ACS Biomater Sci Eng. 2024 Apr 15.
      In this study, we propose a spatially patterned 3D-printed nanohydroxyapatite (nHA)/beta-tricalcium phosphate (β-TCP)/collagen composite scaffold incorporating human dental pulp-derived mesenchymal stem cells (hDP-MSCs) for bone regeneration in critical-sized defects. We investigated angiogenesis and osteogenesis in a rabbit critical-sized mandibular defect model treated with this engineered construct. The critical and synergistic role of collagen coating and incorporation of stem cells in the regeneration process was confirmed by including a cell-free uncoated 3D-printed nHA/β-TCP scaffold, a stem cell-loaded 3D-printed nHA/β-TCP scaffold, and a cell-free collagen-coated 3D-printed nHA/β-TCP scaffold in the experimental design, in addition to an empty defect. Posteuthanasia evaluations through X-ray analysis, histological assessments, immunohistochemistry staining, histomorphometry, and reverse transcription-polymerase chain reaction (RT-PCR) suggest the formation of substantial woven and lamellar bone in the cell-loaded collagen-coated 3D-printed nHA/β-TCP scaffolds. Histomorphometric analysis demonstrated a significant increase in osteoblasts, osteocytes, osteoclasts, bone area, and vascularization compared to that observed in the control group. Conversely, a significant decrease in fibroblasts/fibrocytes and connective tissue was observed in this group compared to that in the control group. RT-PCR indicated a significant upregulation in the expression of osteogenesis-related genes, including BMP2, ALPL, SOX9, Runx2, and SPP1. The findings suggest that the hDP-MSC-loaded 3D-printed nHA/β-TCP/collagen composite scaffold is promising for bone regeneration in critical-sized defects.
    Keywords:  mandibular defects; mesenchymal stem cells; osteogenesis; scaffold design; tissue engineering
    DOI:  https://doi.org/10.1021/acsbiomaterials.4c00580
  13. Arch Dis Child. 2024 Apr 16. pii: archdischild-2023-326201. [Epub ahead of print]
       BACKGROUND: 3D printing has been used in different medical contexts, although it is underutilised in paediatrics. We present the first use of 3D printing in the management of three paediatric patients with complex renovascular disease.
    METHODS: Patient-specific 3D models were produced from conventional 2D imaging and manufactured using 3D polyjet printing technology. All three patients had different underlying pathologies, but all underwent multiple endovascular interventions (renal artery balloon angioplasty) prior to 3D printing and subsequent vascular surgery. The models were verified by an expert radiologist and then presented to the multidisciplinary team to aid with surgical planning.
    RESULTS: Following evaluation of the 3D-printed models, all patients underwent successful uni/bilateral renal auto-transplants and aortic bypass surgery. The 3D models allowed more detailed preoperative discussions and more focused planning of surgical approach, therefore enhancing safer surgical planning. It influenced clinical decision-making and shortened general anaesthetic time. The families and the patients reported that they had a significantly improved understanding of the patient's condition and had more confidence in understanding proposed surgical intervention, thereby contributing to obtaining good-quality informed consent.
    CONCLUSION: 3D printing has a great potential to improve both surgical safety and decision-making as well as patient understanding in the field of paediatrics and may be considered in wider surgical areas.
    Keywords:  Nephrology; Paediatrics; Technology
    DOI:  https://doi.org/10.1136/archdischild-2023-326201
  14. Environ Sci Pollut Res Int. 2024 Apr 16.
      This study investigates nanoparticle emission during 3D printing processes, assessing various filament materials' impact on air quality. Commonly used 3D printers, including both filament and resin-based types, were examined. The study's scope encompasses diverse filament materials like ABS (acrylonitrile butadiene styrene), PLA (polylactic acid), PETG (polyethylene terephthalate glycol), ASA (acrylonitrile styrene acrylate), TPU (thermoplastic polyurethane), PP (polypropylene), nylon, and wood-based variants, alongside three types of resins. The research delves into the relationship between the type of material and nanoparticle emissions, emphasizing temperature's pivotal role. Measurement instruments were employed for nanoparticle quantification, including an engine exhaust particle sizer spectrometer, condensation particle counter, and nanozen dust counters. Notably, results reveal substantial variations in nanoparticle emissions among different filament materials, with ASA, TPU, PP, and ABS showing considerably elevated emission levels and characteristic particle size distribution patterns. The findings prompt practical recommendations for reducing nanoparticle exposure, emphasizing printer confinement, material selection, and adequate ventilation. This study offers insights into potential health risks associated with 3D printing emissions and provides a basis for adopting preventive measures.
    Keywords:  3D printing; Air quality; Emission; Filament materials; Health risks; Nanoparticles; Particle counters; Ventilation
    DOI:  https://doi.org/10.1007/s11356-024-33257-2
  15. Trials. 2024 Apr 16. 25(1): 267
       BACKGROUND: Complete tooth loss is a significant global oral health issue, particularly impacting older individuals with lower socioeconomic status. Computer-assisted technologies enhance oral healthcare access by the elderly. Despite promising in vitro reports on digital denture materials, evidence from randomized clinical trials (RCTs) is lacking to verify their performance. This cross-over RCT will investigate whether 3D-printed implant-retained mandibular overdentures (IMO) are more satisfactory for edentulous seniors than those made through traditional methods.
    METHODS/DESIGN: We will recruit 26 completely edentulous participants (any sex/gender) based on the following eligibility criteria: age ≥ 60 years, no tooth extraction in the past 12 months, two implants in the lower jaw, and need for new dentures in both jaws. Each participant will receive two denture pairs, either manufactured by 3D printing or traditionally, to be worn in a random order. A timeline of 3 months with each denture pair will be considered for outcome assessment (total: 6 months). Patient satisfaction with dentures will be measured by the McGill Denture Satisfaction Questionnaire. We will evaluate other patient-reported outcomes (including oral health-related quality of life) as well as clinician-assessed quality and cost. At the end of the trial, participants will choose which denture pair they wish to keep and interviewed about their experiences with the 3D-printed IMO. The quantitative and qualitative data will be incorporated through an explanatory mixed-methods strategy. A final quantitative assessment will happen after 12 months with the preferred IMO to assess the long-term performance and maintenance needs.
    DISCUSSION: This mixed-methods RCT will explore patient experiences with 3D-printed IMOs, aiming to assess the potential for altering clinical practice and dental public health policies. Our results will inform policies by showing whether 3D printing offers comparable outcomes at lower costs, facilitating greater access to oral care for the elderly.
    TRIAL REGISTRATION: ClinicalTrials.gov, NCT06155630, Registered on 04 December 2023. https://classic.
    CLINICALTRIALS: gov/ct2/show/NCT06155630.
    Keywords:  3D printing; CAD/CAM; Costs and cost analysis; Cross-over studies; Dental care for aged; Edentulous mouth; Implant-supported dental prosthesis; Mandibular overdenture; Patient satisfaction; Removable prosthodontics
    DOI:  https://doi.org/10.1186/s13063-024-08097-7
  16. Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2024 Jan 28. pii: 1672-7347(2024)01-0095-18. [Epub ahead of print]49(1): 95-112
       OBJECTIVES: Anterior cruciate ligament injury is the most common type of knee joint ligament injury. Anterior cruciate ligament reconstruction has a high failure rate, with bone tunnel abnormalities as the most significant factor in these failures. Digital orthopedic technology can effectively develop implementation plans for the revision, thus increasing the success rate. This study aims to develop a surgical plan for anterior cruciate ligament revision by employing multiplanar reconstruction (MPR) for measuring bone tunnel position and diameter, and simulating bone tunnel creation via 3D printing preoperatively.
    METHODS: A total of 12 patients who underwent anterior cruciate ligament revision at the Third Xiangya Hospital of Central South University between 2014 and 2021 were retrospectively studied. The data included patient demographics, preoperative formulated knee joint 3D printing models, and preoperative knee CT scans. The study measured the bone tunnel's diameter and position to guide the establishment of revision bone tunnels during surgery, reassessed the postoperative bone tunnels, and evaluated knee joint functional scores [including International Knee Documentation Committee Knee Evaluation Form (IKDC) score, Lysholm score, and Tegner exercise level score].
    RESULTS: Preoperative measurements revealed suboptimal femoral tunnels positions in 4 patients and tibial tunnels positions in 2 patients. MPR and 3D printing technology were used to guide the establishment of a new bone canal during surgery, and postoperative measurements were satisfactory for all patients. Preoperative measurements demonstrated the interclass correlation coefficient for femoral tunnels and tibial tunnels diameters were 0.843 (P<0.05) and 0.889 (P<0.001), respectively. Meanwhile, the intraclass correlation coefficient were 0.811 (P<0.05) and 0.784 (P<0.05), respectively. The intraoperative diameter of femoral and tibial tunnels showed excellent correlation with postoperative CT measurements, with intraclass correlation coefficient values of 0.995 (P<0.001) and 0.987 (P<0.001), respectively. All bone tunnel positions were within the normal range. At the final follow-up, knee joint function scores in all 12 patients improved significantly compared to pre-surgery (P<0.001), and the reoperation rate was zero.
    CONCLUSIONS: MPR and 3D printing technology can accurately measure the parameters of reconstructed anterior cruciate ligament bone tunnels. Personalized revision plans for patients with reconstruction failure enhances the success rate of revision surgery and improves patient prognosis.
    Keywords:  3D printing; anterior cruciate ligament revision; bone tunnel measure; digital orthopedic technologies; multiplanar reconstruction
    DOI:  https://doi.org/10.11817/j.issn.1672-7347.2024.230081