Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus found in China in 2019. The disease caused by SARS-CoV-2, coronavirus disease 2019 (COVID-19), has been found to be closely related to the cells that secrete angiotensin-converting enzyme 2 (ACE2). ACE2 is involved in the renin-angiotensin system and is widely secreted in several tissues, including the testis, which has raised concerns because organs with high expression of the ACE2 receptor are susceptible to infection. Analyses have shown that in testicular cells, such as spermatogonia, seminiferous duct cells, Sertoli cells, and Leydig cells, there is a high expression level of ACE2. Therefore, SARS-CoV-2 may damage male reproductive tissues and cause infertility. Since male infertility is an important problem, scientists are evaluating whether COVID-19 may influence male infertility through the ACE2 receptor.

Background: Recent developments in 3D printing have gave orthopedic surgeons among a novel technology that has the ability to revolutionize preoperative planning. The appearance of 3D printing technology (3DPT) enables the digital preoperative plan & simulation to move from the virtual phase to the reality phase. Numerous fields of medicine are lately benefiting from the operate of 3D printing, including the arising part of 3D printing in orthopedic surgery. Methods: We searched on PubMed and Google Scholar databases in January 2020 to find papers and studies about using 3D printing in orthopedy for aim of preplanning. The key words for search were (“3D printing” OR “3D-printed Model” OR “three-dimensional Printer”) AND (“Orthopedy” OR “Orthopedics” OR “Orthopedics”) AND (“Surgery” OR “Operation”) AND (“Pre-planning” OR “Plan”) AND (“Fracture” OR “Trauma”) that we used compound. We exclude the papers which their titles or abstracts were not relevant. At last, we select the most related papers to use in this article. Results: The search on PubMed found 80 Papers and on Google Scholar found 104 papers. After excluding similar and unrelated papers, 44 papers were selected for this review article. Conclusion: Almost all studies have shown us that using a 3D model can have a very positive effect on the surgical process and its outcomes, as well as patient and surgeon satisfaction. Therefore, we anticipate that this technology will be used in many orthopedic surgeries in the near future.

Background: This study aimed to assess the use of 3D-printed models for preoperative planning of high tibial osteotomy (HTO) in patients with genu varum deformity. Method: This study included Sixteen patients with genu varum divided into two groups: the model group and the control group. Before and after the operation, all patients in both groups underwent a lower limb standing alignment radiograph to measure mMPTA (mechanical Medial Proximal Tibial Angle), mLDFA (mechanical Lateral Distal Femur Angle), CA (Convergence Angle), and mFTA (mechanical FemuroTibial Angle). For the model group, a 3D-printed model was prepared before the surgery, and open wedge HTO was performed using this model. PTS (posterior tibial slope) and TTA (tibial torsion angle) were also measured in the model group, before and after operation. The control group underwent surgery without using a 3D printed model. Following the operation, the angles and the size of the bone opening in the medial axis on the model that underwent surgery were examined, and the measurements were recorded. Results: There was no significant difference between the groups regarding age, sex, body mass index (BMI), and side of injury. This study found no significant differences in mMPTA, mLDFA, mFTA, and CA between the groups in the 2D image. However, all angles changed significantly in both groups postoperatively, except for mLDFA in the model group. The mean changes in mMPTA, mFTA, and mMLDFA did not significantly differ between the groups, except for CA (P = .012). In the 3D model, PTS increased significantly while TTA decreased. Comparing angles between the 2D image and 3D model showed statistically significant differences, except for mFTA. The size of bone opening along the medial axis did not differ significantly between real surgery and the 3D model. The cost of hospitalization, cost of anesthesia, operation time, and also number of fluoroscopies were significantly lower in the model group compared to the control group. Conclusion: Using a 3D model for preoperative planning improved the correction of genu varum deformity in HTO. It also reduced the operation time, hospitalization and anesthesia costs, and fluoroscopy usage.