ABSTRACT
Objective:To analyze the morphology and distribution characteristics of subchondral bone cysts of the talus by CT three-dimensional reconstruction.Methods:A total of 176 patients diagnosed with subchondral bone cyst of the talus after CT scan of the ankle or foot from 2015 to 2020 were retrieved from the imaging report database of Tianjin Hospital, including 77 males and 99 females, aged 14-84 years［(56.1±14.0)years］. After three-dimensional reconstruction of the talus and cyst area by Mimics 20.0 software, an equal 2×2 grid configuration was constructed to divide the domed articular surface into four regions: anteromedial, anterolateral, posteromedial and posterolateral. For subchondral cyst of the talus, area involved under grid localization, gender, age and side of the onset were recorded. The anteroposterior diameter, transverse diameter, depth, surface area and volume of the subchondral bone cyst of the talus were measured.Results:Subchondral cyst of the talus was anteromedial in 131 patients (74.4%), anterolateral in 5(2.8%), posteromedial in 34(19.3%), and posterolateral in 6(3.4%). Subchondral cyst of the talus occurred in the older aged (≥60 years) for 78 patients (44.3%), in the middle aged (45-59 years) for 62(35.2%), in young adults for 32(18.2%), and in preadolescents for 4(2.3%). The age composition of the subchondral cyst of the talus involving the anteromedial, anterolateral, posteromedial and posterolateral regions was 59(49, 64)years, 44(39, 45)years, 61(54, 68)years and 40(22, 58) years, respectively (all P<0.01). There were no statistically significant differences in gender and side of the onset (all P>0.05). The anteroposterior diameter of the subchondral bone cysts located anteromedially, anterolaterally, posteromedially and posterolaterally was (9.7±4.4)mm, (3.5±1.1)mm, (10.3±4.4)mm and (2.1±0.8)mm, respectively; the transverse diameter was (5.4±1.7)mm, (3.9±1.8)mm, (5.9±2.2)mm and (3.4±1.1)mm, respectively; the depth was (7.1±2.4)mm, (3.2±2.2)mm, (8.2±3.0)mm and (3.9±1.9)mm, respectively; the surface area was 156.1(82.6, 198.2)mm 2, 23.0(21.4, 28.9)mm 2, 180.0(75.1, 230.4)mm 2 and 28.0(20.3, 36.7)mm 2, respectively; the volume was 77.1(37.1, 129.1)mm 3, 23.9(14.2, 37.8)mm 3, 104.6(37.7, 157.4)mm 3 and 13.0(10.4, 16.0)mm 3, respectively. When comparing the anteroposterior diameter, transverse diameter, depth, surface area and volume of the subchondral bone cysts in the anteromedial and posteromedial regions with the anterolateral and posterolateral regions, the differences were statistically significant (all P<0.01) except for the transverse diameter of the subchondral bone cysts in the anteromedial region and the anterolateral region ( P>0.05). In addition, the depth of subchondral bone cysts in the anteromedial region was significantly greater than that in the posteromedial region ( P<0.05). Conclusions:Subchondral bone cysts of the talar are commonly found in the middle- and old-aged population. Anteromedial lesions of the talar dome are the most commonly seen, with large and deeply involved cysts, followed by posteromedial lesions of the dome, while anterolateral and posterolateral lesions of the dome are less common and have smaller cyst sizes. An equal 2×2 grid configuration for talar cysts is useful in positioning and characterizing bone cysts, and can assist clinicians in accurately diagnosing and treating bone cysts.
ABSTRACT
A 3D printed patient-specific surgical guide plate is an auxiliary device made with the help of computer-aided design and 3D printing technology according to a surgical plan. It is used in reduction and internal fixation of fracture and specific corrective osteotomy as well. It is very adaptive as it has been widely used in trauma surgery, joint surgery and spine surgery, as well as in surgical treatment of bone tumors. Digital orthopedic technology is an important means to realize orthopedic precision medicine. This paper reviews the technical advantages, applications, main problems and future prospects of 3D printed patient-specific surgical guide plates in the field of orthopedics based on the recent literature.
ABSTRACT
Objective To find out the display rules of the key part of the proximal femur and fracture line and obtain the best viewing position and angle by placing the femoral neck at different positions and different angles through X-ray.Methods Six dry specimens of cadaveric femur were from Department of Anatomy,Tianjin Medical University.Three models of complete femoral neck model,tin line fracture model and steel saw fracture model were made respectively.The tin line fracture model was based on the Pauwells angle,using the tin wire(1mm) wrapped around the femoral necks to make three kinds of fracture models (Pauwells angle 30°,50° and 70°);steel saw fracture model was made by hacksaw,then reposition in situ,to make three kinds of fracture models same as the tin line fracture model.The projection manner included different positions and different angles,different projection positions include:parallel with the femoral shaft,perpendicular to the femoral shaft,parallel to the femoral neck and perpendicular to the femoral neck;different projection angles included:from 40°,30°,20°,15°,10° and 5° in the head side to 5°,10°,15 °,20 °,30 °and 40° in the foot side and vertical angle 0°.For the complete femoral neck model,we observed the imaging characteristics of the key parts of the femoral head and neck (tension trabecular bone and pressure trabecular bone;lesser trochanter;intertrochanteric line;length of neck of femur and femoral head shape),looking for the display rules,and obtained the best viewing position.For tin line fracture model and steel saw fracture model,we tried to find the best display angle and position by the different projection position and angle.Results The results of complete femoral neck model:Lesser trochanter:in perpendicular to the femoral shaft position showed the best,gradually increased with the foot side deflection;tension trabecular bone and pressure trabecular bone:in parallel with the femoral shaft position 10°on the head side;intertrochanteric line:no difference between parallel with the femoral shaft with perpendicular to the femoral shaft;Femoral neck shape:deflect to both sides,head of femur was out of shape.The results of tin line fracture model:the Pauwells angle 30° model showed the best position in parallel with the femoral shaft position 20° on the head side;the Pauwells angle 50° model showed the best position in parallel with the femoral shaft position 5° on the head side;the Pauwells angle 70° model showed the best position in parallel with the femoral shaft position 10° on the head side.The results of steel saw fracture model were the same with the tin line fracture model.Conclusion There was the best viewing angles and positions for the key anatomy of the proximal femur and different Pauwells angle classification of femoral neck fracture.The image doctor could make more accurate projection,according to the different types of femoral neck fracture.