Printed three-dimensional anatomic templates for virtual preoperative planning before reconstruction of old pelvic injuries: initial results / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy, difficult-to-access surgical sites, and the relatively low incidence of such cases. Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture. The goal of this study was to assess the use of three-dimensional (3D) printing techniques for surgical management of old pelvic fractures.</p><p><b>METHODS</b>First, 16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data. Next, nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models. The pelvic injuries were all type C, and the average time from injury to reconstruction was 11 weeks (range: 8-17 weeks). The workflow consisted of: (1) Printing patient-specific bone models based on preoperative computed tomography (CT) scans, (2) virtual fracture reduction using the printed 3D anatomic template, (3) virtual fracture fixation using Kirschner wires, and (4) preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation. These models aided communication between surgical team members during the procedure. This technique was validated by comparing the preoperative planning to the intraoperative procedure.</p><p><b>RESULTS</b>The accuracy of the 3D printed models was within specification. Production of a model from standard CT DICOM data took 7 hours (range: 6-9 hours). Preoperative planning using the 3D printed models was feasible in all cases. Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases. The patients were followed for 3-29 months (median: 5 months). The fracture healing time was 9-17 weeks (mean: 10 weeks). No delayed incision healing, wound infection, or nonunions occurred. The results were excellent in two cases, good in five, and poor in two based on the Majeed score.</p><p><b>CONCLUSIONS</b>The 3D printing planning technique for pelvic surgery was successfully integrated into a clinical workflow to improve patient-specific preoperative planning by providing a visual and haptic model of the injury and allowing patient-specific adaptation of each osteosynthesis implant to the virtually reduced pelvis.</p>

Long-term outcome of operative management of delayed acetabular fractures / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Surgical treatment of acetabular fracture has long been a challenging area in the field of orthopedic trauma. The aim of this research was to investigate the operative methods for delayed acetabular fractures and to assess the operation results.</p><p><b>METHODS</b>The operative approaches, procedures, results, and complications of the delayed acetabular fractures between 1995 and 2005 were retrospectively evaluated at Beijing Jishuitan Hospital. Quality of life was assessed for each patient with the Merle d'Aubingne and Postel fracture function rating scale and the radiological result was assessed using the Matta radiological score.</p><p><b>RESULTS</b>Sixty-eight cases (70 hips) were followed up with a minimal duration of five years (average of 5.8 years). Excellent functional results were observed in 10 hip joints, good results in 40, fair results in 11, and poor results in nine. The risks of poor prognosis include impact fracture or osteochondral fracture of femoral head, a time beyond 42 days from injury to operative management, and dislocation of femoral head during the injury. Some of the problems, which were observed included postoperative infection in two hips, iatrogenic sciatic nerve injury in eight hips, traumatic arthritis in 15 hips, heterotopic ossification in 17 hips, and necrosis of the femoral head in six hips.</p><p><b>CONCLUSION</b>A careful selection of operative indications for delayed acetabular fractures in combination with a proper operative approach and appropriate reduction and fixation could guarantee relatively good results.</p>

Percutaneous pelvic fracture stabilization using CT-based 3D navigation software combined with targeting mechanical arm: a cadaver model trial / 中华外科杂志

<p><b>OBJECTIVES</b>To investigate a new targeting mechanical arm for CT-based navigated percutaneous fixation of pelvic fractures, and to evaluate the safety and efficiency of the procedures.</p><p><b>METHODS</b>Using CT-based 3D navigation software combined with targeting mechanical arm, percutaneous insertion of pelvic models (3 dry human cadaver pelvic skeletons and 5 plastic Sybone pelvic models) were performed, 8 pelvic models allowed percutaneous cannulated screw insertion of both S-I joint (2 S-I screws placement for each side, total 32 screws in this experiment) and both superior ramus (1 ramus medullary screw placement for each side, total 16 screws in this experiment). Percutaneous insertion of pelvic models (4 dry human cadaver pelvic skeletons and 4 plastic Sybone pelvic models, 1 S-I screws and 1 ramus medullary scre placement for each side, 32 screws in this experiment) were performed using fluoro-navigation system (Stryker, USA). Time necessary for every screw insertion were recorded. Accuracy of screw placement was assessed using C-arm imaging and direct eyes inspecting. The time and accuracy of the two methods were compared.</p><p><b>RESULTS</b>The time required for the CT-based 3D navigation procedure (3.6 ± 1.2) min was significantly less than using the targeting mechanical arm compared to drilling freehand with navigation (9.1 ± 0.8) min (t = 2.50, P < 0.01). There was no significant difference in accuracy between the two methods.</p><p><b>CONCLUSION</b>CT-based 3D navigation software combined with targeting mechanical arm should be potential to apply percutaneous sacroiliac screwing for pelvic fractures with more accurate and more reliable.</p>

Computer-assisted navigation systems for insertion of cannulated screws in femoral neck fractures: a comparison of bi-planar robot navigation with optoelectronic navigation in a Synbone hip model trial / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Computer-assisted procedures have recently been introduced for navigated femoral neck screw placement. Currently there is little information available regarding accuracy and efficiency of the different navigated procedures. The aim of this study was to compare two fluoroscopic navigation tracking technologies, a novel bi-planar robot navigation and standardized optoelectronic navigation, versus standard freehand fluoroscopic insertion in a Synbone hip model.</p><p><b>METHODS</b>Eighteen fixed Synbone hip models were divided into 3 groups. C-arm navigated cannulated screws (AO-ASIF, diameter 7.3 mm) were inserted using freehand targeting (control group). A novel bi-planar robot system (TINAV, GD2000) and an optoelectronic system (Stryker OTS Navigation System) were used for the navigated procedures (robot group and optoelectronic group). Accuracy was measured using radiographic evaluation including the measurement of screw parallelism and decentralization, and joint penetration. To evaluate the efficiency, the number of guidewire passes, operative time and fluoroscopic images taken were noted.</p><p><b>RESULTS</b>The two computer-assisted systems provided significantly improved accuracy compared to the freehand technique. Each of the parameters, including guidewire passes and number of fluoroscopy images, was significantly lower when using the computer-assisted systems than for freehand-unguided insertion (P <0.05), but operative time was significantly shorter when using freehand-unguided insertion than for the computer-assisted systems (P <0.05). Accuracy, operative time and number of fluoroscopy images taken were similar among the two navigated groups (P >0.05), but guidewire passes in the robot group were significantly less than in the optoelectronic group (P <0.05).</p><p><b>CONCLUSIONS</b>Both bi-planar robot navigation and optoelectronic navigation were similarly accurate and have the potential to improve accuracy and reduce radiation for freehand fluoroscopic targeting for insertion of cannulated screws in femoral neck fractures. Guidewire passes in the robot group were significantly less than in the optoelectronic group. However, both navigated procedures were associated with time-consuming registration and high rates of failed matching procedures.</p>

Primary clinical application of traction reductor for lower limb fracture / 中华外科杂志

<p><b>OBJECTIVE</b>To develop a traction reductor for the reduction of lower limb fractures during the minimally invasive surgery and explore its safety and efficacy.</p><p><b>METHODS</b>From February 2007 to March 2009, closed or limited open reduction plus percutaneous plate and screw internal-fixation were conducted in 34 patients with fracture of distal femur and tibia metaphysic, among which there were 3 distal femoral fractures (2 33-B, 1 33-C), 14 proximal tibial fractures (9 41-A, 3 41-B, 2 41-C) and 17 distal tibial fractures (9 43-A, 5 43-B, 3 43-C, 2 Gustilo I a), according to the Association for Osteosynthesis-Orthopaedic Trauma Association (AO-OTA) classification. Besides, closed reduction plus interlocking intramedullary nailing on tibial shaft fracture were applied in 36 patients (7 42-A, 21 42-B, 8 42-C, 2 Gustilo I a). All the 70 patients, with an average age of 37.6 years (range: 17 to 63 years) and average time before surgery of 4.7 d (range: 0.7 to 12.0 d), underwent reduction by self-designed traction reductor for lower limb fracture in the surgery. The reduction duration and C-arm fluoroscopy time were recorded. Recovery of the force line of affected limbs after surgery was determined by whether the line from anterior superior iliac spine to the interdigit between the first and second toe-web passed the patella center. And the distance from bilateral anterior superior iliac spine to medial malleolus tip as well as the difference between lower limbs were recorded to determine the recovery of length after surgery. Meanwhile, the varus-valgus and anteroposterior angulations after reduction were measured by AP and lateral X-ray.</p><p><b>RESULTS</b>The reduction duration was 12.7 min (range: 7 to 31 min); X-ray fluoroscopy time, 1.3 min (range: 0.4 to 3.0 min); length difference between both lower limbs (6.5 ± 1.1) mm; and axial alignment difference (7.0 ± 1.8) mm. The X-ray result showed that varus-valgus angle was (2.75 ± 0.16)°; and anteroposterior angulation (5.13 ± 0.51)°.</p><p><b>CONCLUSION</b>The traction reductor for lower limb fracture could achieve satisfying fracture reduction in the minimally invasive surgery of distal femur, tibia metaphysic and tibial shaft fracture.</p>

Computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails: a preliminary report on clinical application / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the clinical feasibility and effect of the computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails.</p><p><b>METHODS</b>The hardware components of the system included a PC computer with a monitor, auto mechanical stereotactical localization cubic frame, foot holder and localization operative apparatus. Special navigation software can be used for registration of X-ray fluoroscopic images and real-time controlling navigation of tools. Twenty-one cases of close tibial and fibular fractures were treated with closed intramedullary nailing, 6 of which involved in middle third, 12 in middle and lower third, 3 in lower third. C-arm alignment and registration time, fluoroscopic time and drilling time involved in the locking procedure were recorded. The size of unreamed or reamed tibial nails ranged from 8/300-11/330.</p><p><b>RESULTS</b>All distal holes except 1 were locked successfully. In 9 of 41 locked holes (21.95%), the drill bit touched the canal of locking hole without damage of the nail and clinical consequences. The fluoroscopy time per pair of screws was 2.23+/-0.31 s.</p><p><b>CONCLUSIONS</b>The computer-assisted auto-frame navigation system for distal locking is well designed, easy to operate and do not need additional instruments during the procedure. The developed system enables the physician to precisely navigate surgical instruments throughout the anatomy using just a few computer-calibrated radiographic images. The total time of X-ray exposure per procedure can be significantly reduced.</p>

Protective Effect of Progesterone on Brain Edema in Newborn Rats with Hypoxic-Is chemic Encephalopathy / 实用儿科临床杂志

Objective To observe the protective effect of progesterone on brain edema in newborn rats with hypoxic-ischemic encephalopathy(HIE).Methods Fifty-two 7-day-old neonatal rats were randomly divided into 5 groups:normol control group(group A),hypoxic-ischemic group (group B) and pretreatment groups(group C,D and E).Rats were subjected to left common carotid artery ligation,then were exposed to 8% oxygen and 92% nitrogen for 2.5 hours to establish HIE model.Progesterone was injected intraperitoneally into the groups C,D and E rats respectively at 30 minutes before hypoxia.All rats were killed at the 24 hours after operations,then the contents of water,sodium,potassium were mensurated. Results The contentation of water in group B was higher than that in group A,the contentation of water,sodium in groups C,D and E were significantly lower compared with group B, but the contents potassium were no difference between group C,E and B. Conclusion Progesterone exerts a prominent preventive and protetive effects on the hypoxic ischemic brain edema in newborn rats.