BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.

BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.

Objective To compare the biomechanical characteristics of novel retrograde intramedullary nail,common femoral retrograde intramedullary nail,and medial femoral condyle locking plate for treating distal femur type A fractures by finite element analysis,and study the advantages of retrograde intramedullary nail on medial femoral condyle.Methods A novel retrograde intramedullary nail on medial femur condyle was designed.CT scan was performed on lower limb bones of a male volunteer,and a three-dimensional(3D)model of the femur was established.The model was then segmented to create models of distal femur type A2 and A3 fractures.The 3D models of internal fixator were established.The small and standard retrograde intramedullary nail on medial femoral condyle,common femoral retrograde intramedullary nail,locking plate on medial femoral condyle were used for internal fixation on A2 type fracture.A3 type fracture was fixed with one of the above internal fixators combined with lateral condylar plate respectively.The 600 N axial load and 4 N·m torsional load were applied to the models.The displacement and stress of femurs,the displacement and stress of internal fixators,the micro-momentum between the internal fixator and the bone,the relative displacement of the two fracture broken ends were observed in each group.Results Among the A2 and A3 type fractures under axial loads,the correponding standard group and corresponding standard combined group had the smallest peak displacement and peak stress of internal fixation.Among the A2 and A3 type fractures under torsional loads,the correponding standard group and corresponding standard combined group had the smallest peak displacement of the femur and internal fixation.The relative displacement of the two broken ends in the standard combined group was the smallest.Conclusions Compared with femoral medial condylar locking plate and common retrograde intramedullary nail,this novel retrograde intramedullary nail on medial femur condyle has a mechanical advantage of reducing stress concentration and reducing the risk of internal fixation failure,and it can be used alone for distal femur type A2 fracture,or in combination with the lateral condylar plate to fix distal femur type A3 fracture.

Objective To compare the biomechanical characteristics of novel retrograde intramedullary nail,common femoral retrograde intramedullary nail,and medial femoral condyle locking plate for treating distal femur type A fractures by finite element analysis,and study the advantages of retrograde intramedullary nail on medial femoral condyle.Methods A novel retrograde intramedullary nail on medial femur condyle was designed.CT scan was performed on lower limb bones of a male volunteer,and a three-dimensional(3D)model of the femur was established.The model was then segmented to create models of distal femur type A2 and A3 fractures.The 3D models of internal fixator were established.The small and standard retrograde intramedullary nail on medial femoral condyle,common femoral retrograde intramedullary nail,locking plate on medial femoral condyle were used for internal fixation on A2 type fracture.A3 type fracture was fixed with one of the above internal fixators combined with lateral condylar plate respectively.The 600 N axial load and 4 N·m torsional load were applied to the models.The displacement and stress of femurs,the displacement and stress of internal fixators,the micro-momentum between the internal fixator and the bone,the relative displacement of the two fracture broken ends were observed in each group.Results Among the A2 and A3 type fractures under axial loads,the correponding standard group and corresponding standard combined group had the smallest peak displacement and peak stress of internal fixation.Among the A2 and A3 type fractures under torsional loads,the correponding standard group and corresponding standard combined group had the smallest peak displacement of the femur and internal fixation.The relative displacement of the two broken ends in the standard combined group was the smallest.Conclusions Compared with femoral medial condylar locking plate and common retrograde intramedullary nail,this novel retrograde intramedullary nail on medial femur condyle has a mechanical advantage of reducing stress concentration and reducing the risk of internal fixation failure,and it can be used alone for distal femur type A2 fracture,or in combination with the lateral condylar plate to fix distal femur type A3 fracture.

A 55-year-old male patient was admitted to the hospital due to "recurrent chest pain for 8 months, with worsening symptoms for 2 weeks". After admission, comprehensive relevant examinations led to the consideration of a giant chronic left ventricular pseudoaneurysm caused by myocardial infarction with non-obstructive coronary arteries. Surgical treatment was performed at our hospital. We discuss the diagnosis and treatment of this patient.

Cryoablation therapy with explicit anti-tumor mechanisms and histopathological manifestations has a long history.A large number of clinical practice has shown that cryoablation therapy is safe and effective,making it an ideal tumor treatment method in theory.Previously,its efficacy and clinical application were constrained by the limitations of refrigerants and refrigeration equipment.With the development of the new generation of cryoablation equipment represented by argon helium knives,significant progress has been made in refrigeration efficien-cy,ablation range,and precise temperature measurement,greatly promoting the progression of tumor cryoablation technology.This consensus systematically summarizes the mechanism of cryoablation technology,indications for oral mucosal melanoma(OMM)cryotherapy,clinical treatment process,adverse reactions and management,cryotherapy combination therapy,etc.,aiming to provide reference for carrying out the standardized cryoablation therapy of OMM.

Objective To investigate preliminary clinical effects of three-dimensional(3D)printing combined with minimally invasive percutaneous plate osteosynthesis(MIPPO)in the treatment of anterior pelvic ring injuries.Methods Between December 2017 and July 2023,we treated 15 patients with anterior pelvic ring injuries by using 3D printing combined with MIPPO.Before surgery,a 3D model was printed to establish the actual structure,and a steel plate was pre-bent outside the body to simulate the surgery,as well as the design of number,direction,and length of screws.Then,the pre-bent internal fixation device was inserted through the bone membrane tunnel in the anterior pelvic ring,and the screws were fixed through both sides of the incision according to the preoperative planning.Results All the 15 patients underwent surgery successfully without complications such as nerve and vascular injury.The operation time was(162.9±63.1)min,the total length of incision was(13.5±2.2)cm,the number of fluoroscopic examinations during the surgery was(5.5±1.0)times,and the amount of blood loss was(456.7±272.5)ml.The fracture healing time was(17.5±1.8)weeks.The 15 patients were followed up for(15.2±3.9)months.The Majeed functional score increased significantly from(18.3±2.3)points before surgery to(86.3±6.0)points at 6 months postoperatively(t=-47.313,P=0.000).The fracture reduction according to the Matta standards showed excellent in 14 patients,fair in one patient,the excellent and good rate being 93.3％(14/15).Conclusion Combination of 3D printing and MIPPO treatment for anterior pelvic ring injuries can achieve good clinical effects.

Objective To investigate preliminary clinical effects of three-dimensional(3D)printing combined with minimally invasive percutaneous plate osteosynthesis(MIPPO)in the treatment of anterior pelvic ring injuries.Methods Between December 2017 and July 2023,we treated 15 patients with anterior pelvic ring injuries by using 3D printing combined with MIPPO.Before surgery,a 3D model was printed to establish the actual structure,and a steel plate was pre-bent outside the body to simulate the surgery,as well as the design of number,direction,and length of screws.Then,the pre-bent internal fixation device was inserted through the bone membrane tunnel in the anterior pelvic ring,and the screws were fixed through both sides of the incision according to the preoperative planning.Results All the 15 patients underwent surgery successfully without complications such as nerve and vascular injury.The operation time was(162.9±63.1)min,the total length of incision was(13.5±2.2)cm,the number of fluoroscopic examinations during the surgery was(5.5±1.0)times,and the amount of blood loss was(456.7±272.5)ml.The fracture healing time was(17.5±1.8)weeks.The 15 patients were followed up for(15.2±3.9)months.The Majeed functional score increased significantly from(18.3±2.3)points before surgery to(86.3±6.0)points at 6 months postoperatively(t=-47.313,P=0.000).The fracture reduction according to the Matta standards showed excellent in 14 patients,fair in one patient,the excellent and good rate being 93.3％(14/15).Conclusion Combination of 3D printing and MIPPO treatment for anterior pelvic ring injuries can achieve good clinical effects.

Objective:To explore the clinical efficacy of internal fixation with a reduction plate assisted by our self-designed lower extremity fracture traction reduction device for tibial plateau fractures of Schatzker type Ⅵ.Methods:A retrospective study was conducted of the 32 patients with tibial plateau fracture of Schatzker type Ⅵ who had been treated at Orthopaedic Department, Mindong Hospital Affiliated to Fujian Medical University from April 2018 to July 2021. Depending on their treatments, they were divided into 2 groups. In the control group of 16 cases subjected to open reduction and internal fixation with manual traction, there were 9 males and 7 females with an age of 50.0±11.7 years; in the observation group of 16 cases subjected to internal fixation with a reduction plate assisted by our self-designed lower extremity fracture traction reduction device, there were 8 males and 8 females with an age of 54.6±11.1 years. The operation time, fracture reduction time, total incision length, intraoperative blood loss, Rasmussen knee function score and maximum active range of knee motion were compared between the 2 groups.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability between the groups ( P>0.05). The operation time [(158.6±26.0) min], fracture reduction time [(61.6±9.6) min], and total incision length [16.0 (13.3, 17.0) cm] in the observation group were significantly shorter than those in the control group [(199.9±60.9) min, (73.8±17.2) min, and 20.0 (17.0, 21.8) cm]; the intraoperative blood loss [175.0 (100.0, 200.0) mL] in the observation group was significantly less than that in the control group [200.0 (162.5, 387.5) mL]; the maximum active ranges of knee motion at one week and one month in the observation group were 94.9°±12.0° and 113.8°±14.1°, significantly larger than those in the control group (78.3°±14.6° and 96.8°±11.4°) (all P<0.05). Fractures achieved bony union at one year after operation in both groups. At 12 months after operation, there was no significant difference in the maximum active range of knee motion or the Rasmussen knee function score between the 2 groups ( P>0.05). Conclusion:In the treatment of Schatzker type Ⅵ tibial plateau fractures, compared with manual traction and open reduction, internal fixation with a reduction plate assisted by our self-designed lower extremity fracture traction reduction device can shorten operation time and total incision length, reduce intraoperative blood loss, and facilitate postoperative functional recovery of the knee for the patients.

Objective:To explore the feasibility of direct renin inhibitor aliskiren for the treatment of severe or critical coronavirus disease 2019 (COVID-19) patients with hypertension.Methods:The antihypertensive effects and safety of aliskiren was retrospectively analyzed in three severe and one critical COVID-19 patients with hypertension.Results:Four patients, two males and two females, with an average age of 78 years (66-87 years), were referred to hospital mainly because of respiratory symptoms. Three were diagnosed by positive novel coronavirus 2019 (2019-nCoV) nucleic acid or antibody, and the critical patient with cardiac insufficiency was clinically determined. Two patients were treated with calcium channel antagonist (CCB), one with angiotensin converting enzyme inhibitor (ACEI), and one with angiotensin Ⅱ receptor antagonist (ARB). After admission, ACEI and ARB were discontinued, one patient with heart failure was treated by aliskiren combined with diuretic.Three patients were treated with aliskiren combined with CCB among whom two withdrew CCB due to low blood pressure after 1 to 2 weeks. Based on comprehensive treatment including antiviral and oxygenation treatment, blood pressure was satisfactorily controlled by aliskiren after three to four weeks without serious adverse events. All patients were finally discharged.Conclusion:Our preliminary clinical data shows that antihypertensive effect of aliskiren is satisfactory and safe for severe COVID-19 patients complicated with hypertension.