Objective Mechanic strength, pore morphology and size are key factors for the three-dimensional (3D) printing of porous titanium scaffolds, therefore, developing optimal structure for the 3D printed titanium scaffold to fill bone defects in knee joints is instructive and important. Methods Structural models of titanium scaffolds with fifteen different pore unit were designed with 3D printing computer software; five different scaffold shapes were designed: imitation diamond-60°, imitation diamond-90°, imitation diamond-120°, regular tetrahedron and regular hexahedron. Each structural shape was evaluated with three pore sizes (400, 600 and 800 μm), and fifteen types of cylindrical models (size: 20 mm; height: 20 mm). Autodesk Inventor software was used to determine the strength and safety of the models by simulating simple strength acting on the knee joints. We analyzed the data and found suitable models for the design of 3D printing of porous titanium scaffolds. Results Fifteen different types of pore unit structural models were evaluated under positive pressure and lateral pressure; the compressive strength reduced when the pore size increased. Under torsional pressure, the strengths of the imitation diamond structure were similar when the pore size increased, and the strengths of the regular tetrahedron and regular hexahedron structures reduced when the pore size increased. In each case, the compressive strength of the regular hexahedron structure was highest, that of the regular tetrahedron was second highest, and that of the imitation diamond structure was relatively low. Fifteen types of cylindrical models under a set force were evaluated, and the sequence of comprehensive compressive strength, from strong to weak was: regular hexahedron > regular tetrahedron > imitation diamond-120° > imitation diamond-90° > imitation diamond-60°. The compressive strength of cylinder models was higher when the pore size was smaller. Conclusion The pore size and pore morphology were important factors influencing the compressive strength. The strength of each structure reduced when the pore size (400, 600 and 800 μm) increased. The models of regular hexahedron, regular tetrahedron and imitation diamond-120°appeared to meet the conditions of large pore sizes and high compressive strength.
Objective To explore the comparison of clinical efficacy between femoral neck system(FNS)and hollow screw inverted triangle fixation for femoral neck fracture patients with comminuted posterior medial wall.Methods From December 2019 to August 2021,fresh femoral neck fracture patients with comminuted posterior medial wall were treated by FNS(FNS group,21 cases)and cannulated screw inverted triangle fixation(cannulated compression screw group,22 cases)in Fuyang People's Hospital.There were 19 males and 24 females,aged from 18-59 years.The observation indexes included intraoperative fluoroscopy,operation time,Garden index,Haidukewych standard score,cortical support,the fracture healing time,the time of full weight-bearing,femoral neck shortening length,failure of internal fixation and the occurrence of femoral head necrosis.Results The postoperative follow-up of the two groups was 12-24 months,with an average of(18.60±4.10)months.There was a significant difference in the frequency of intraoperative fluoroscopy between the two groups(P<0.05).There was no significant difference in operation time,Garden index,Haidukewych score and cortical support between the two groups(P>0.05).There was no significant difference in fracture healing time and Harris hip score between the two groups(P>0.05).The incisions of both groups healed first after surgery.In the cannulated screw group,there was 1 case of internal fixation failure,cannulated screw cutting,nail withdrawal,fracture displacement and coxa vara deformity.The FNS group was superior to the cannulated compression screw group in the time of full weight-bearing,femoral neck shortening,and femoral head necrosis rate(P<0.05).Conclusion For femoral neck fractures with posterior medial wall comminuted,FNS fixation can reduce intraoperative fluoroscopy and femoral neck shortening,facilitate early weight-bearing activities,and lower the rate of femoral head necrosis in early follow-up.
Objective To compare the effects and economic differences of shoulder joint range of motion,pain stress and inflammatory factors in patients with Goss-Ideberg type Ⅰa scapular glenoid fracture and open reduction and cannulated screw internal fixation assisted by shoulder arthroscopy.Methods From August 2014 to August 2022,30 patients with glenoid fracture were selected from Huangshi Love&Health Hospital Affiliated of Hubei Polytechnic University for orthopedic surgery through retrospective study.They were divided into two groups according to the treatment methods of open reduction and internal fixation and reduction and internal fixation under arthroscopy,namely,the minimally invasive group(surgery assisted by arthroscopy,n=15)and the incision group(conventional incision surgery,n=15).The operation index,shoulder joint activity 1 month and 3 months after operation,pain stress indicators before and 7 d after operation,and treatment costs were recorded.Results The incision length of the incision group was significantly longer than that of the minimally invasive group,and the intraoperative blood volume was more than that of the minimally invasive group.The operation time of the minimally invasive group was significantly longer than that of the incision group,and the treatment cost was significantly higher than that of the incision group.The levels of prostaglandin E2 and inflammatory factors including C-reactive protein in the two groups at 7 d after operation were significantly higher than those before surgery,but the level in the minimally invasive group was lower than that in the incision group.The degree of lateral and circumferential rotation of the shoulder joint in the early postoperative period(1 month)and the Constant score in the minimally invasive group were higher than that in the incision group,with a statistically significant difference(P<0.05).Conclusion Fixation of glenoid fracture with wire anchor nail under shoulder arthroscopy can significantly improve the early rotation of the shoulder joint,and help to improve its pain stress.The constant score is higher,which can improve the treatment effect of patients,improve limb function,shorten the surgical incision,and reduce intraoperative bleeding.However,the operation time is long and the treatment cost is high in the minimally invasive group.
Objective To investigate the feasibility of bone cement augmented proximal femoral anti-rotation nail in the treatment of Seinsheimer type Ⅴ subtrochanteric fractures in the elderly.Methods The CT data of one volunteer was imported into Mimics 19.0 and Geomagic studio 2017 to extract and optimize the 3D model of the right femur.Draw internal fixation model and assembled with femur model according to the standard operation technology,then imported into Hypermesh 14.0 software to simulating Seinsheimer type Ⅴ subtrochanteric fractures.The cancellous bone around the proximal helical blade was redefined as bone cement,obtaining bone cement augmented proximal femoral anti-rotation nail model.The material property parameters,boundary conditions,and applied loads were set and imported into LS-DYNA software for solution.Results ①Compared with the common proximal femoral anti-rotation nail model,the helical blade of the bone cement augmented proximal femoral anti-rotation nail model had no cutting,and the varus and rotation angle of the head and neck bone block was smaller.Although the local stress was slightly larger,the whole was more stable.②The strong anchoring force of bone cement can stabilize the helical blade,improve the inner action point of the three-point support,and transmit and disperse the pressure.Conclusion Compared with the common proximal femoral anti-rotation nail,the bone cement augmented proximal femoral anti-rotation nail could effectively reduce the varus rotation of the head and neck bone block in the treatment of Seinsheimer type Ⅴ subtrochanteric fractures in elderly patients,avoid the cutting of the spiral blade,and offer enhanced stability.
Objective To compare the efficacy of closed prying reduction and percutaneous screw internal fixation with oblique plastic plate internal fixation in the treatment of tongue shaped calcaneal fractures.Methods A total of 68 patients with tongue shaped calcaneal fracture admitted to Sichuan Orthopedic Hospital from January 2016 to May 2018 were retrospectively selected,and the patients were divided into two groups according to the different surgical methods.Among them,35 patients were treated with closed prying reduction and percutaneous screw internal fixation(closed reduction group),and the remaining 33 patients were treated with inclined contoured internal fixation(oblique plate group).The operation time,hospitalization time,fracture healing time and postoperative calcaneal height,Böhler angle,complications and long-term prognosis were observed in both groups.Results A total of 68 cases were followed up for three years after operation.The operation time,hospitalization time and fracture healing time of the closed reduction group were significantly shorter than those of the oblique plate group(P<0.05).There was no significant difference in calcaneus height and Böhler angle between the two groups(P>0.05).There was no significant difference in the total incidence of complications and long-term prognosis between the two groups(P>0.05).Conclusion Closed prying reduction and percutaneous screw internal fixation can shorten the operation time,hospitalization time and fracture healing time of tongue shaped calcaneal fracture.Compared with oblique contoured internal fixation,there is no significant difference in correcting calcaneal height,Böhler angle,short-term and long-term complications.
