Percutaneous Sacroiliac Screw Placement: A Prospective Randomized Comparison of Robot-assisted Navigation Procedures with a Conventional Technique / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Sacroiliac (SI) screw fixation is a demanding technique, with a high rate of screw malposition due to the complex pelvic anatomy. TiRobot™ is an orthopedic surgery robot which can be used for SI screw fixation. This study aimed to evaluate the accuracy of robot-assisted placement of SI screws compared with a freehand technique.</p><p><b>METHODS</b>Thirty patients requiring posterior pelvic ring stabilization were randomized to receive freehand or robot-assisted SI screw fixation, between January 2016 and June 2016 at Beijing Jishuitan Hospital. Forty-five screws were placed at levels S1 and S2. In both methods, the primary end point screw position was assessed and classified using postoperative computed tomography. Fisher's exact probability test was used to analyze the screws' positions. Secondary end points, such as duration of trajectory planning, surgical time after reduction of the pelvis, insertion time for guide wire, number of guide wire attempts, and radiation exposure without pelvic reduction, were also assessed.</p><p><b>RESULTS</b>Twenty-three screws were placed in the robot-assisted group and 22 screws in the freehand group; no postoperative complications or revisions were reported. The excellent and good rate of screw placement was 100% in the robot-assisted group and 95% in the freehand group. The P value (0.009) showed the same superiority in screw distribution. The fluoroscopy time after pelvic reduction in the robot-assisted group was significantly shorter than that in the freehand group (median [Q1, Q3]: 6.0 [6.0, 9.0] s vs. median [Q1, Q3]: 36.0 [21.5, 48.0] s; χ2 = 13.590, respectively, P < 0.001); no difference in operation time after reduction of the pelvis was noted (χ2 = 1.990, P = 0.158). Time for guide wire insertion was significantly shorter for the robot-assisted group than that for the freehand group (median [Q1, Q3]: 2.0 [2.0, 2.7] min vs. median [Q1, Q3]: 19.0 [15.5, 45.0] min; χ2 = 20.952, respectively, P < 0.001). The number of guide wire attempts in the robot-assisted group was significantly less than that in the freehand group (median [Q1, Q3]: 1.0 [1.0,1.0] time vs. median [Q1, Q3]: 7.0 [1.0, 9.0] times; χ2 = 15.771, respectively, P < 0.001). The instrumented SI levels did not differ between both groups (from S1 to S2, χ2 = 4.760, P = 0.093).</p><p><b>CONCLUSIONS</b>Accuracy of the robot-assisted technique was superior to that of the freehand technique. Robot-assisted navigation is safe for unstable posterior pelvic ring stabilization, especially in S1, but also in S2. SI screw insertion with robot-assisted navigation is clinically feasible.</p>

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>

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>

Design and experimental study of computer-assisted orthopaedic system for distal locking of intramedullary nails / 中华外科杂志

<p><b>OBJECTIVE</b>To test the safety and accuracy of the computer-assisted orthopaedic system for distal locking of intramedullary nails and apply it to internal fixation with intramedullary nails in the lower limb.</p><p><b>METHODS</b>According to the theory of mechanical arms stereotactic localization in computer-assisted orthopaedic surgery (CAOS), we design a CAOS system for distal locking of intramedullary nails. The system comprised 2 independent modules: computer-assisted imaging and registration workstation; mechanical stereotactic framework. Ten plastic tibia models, 20 plastic femur models (Synbone AG, Malans, Switzerland) and 6 human cadaver lower limbs were randomly divided into 2 groups undergoing internal fixation with intramedullary nails (Orthofix, Germany). The first group (CAOS group with 5 plastic tibia models, 10 plastic femur models, 6 human cadaver tibia, 6 human cadaver femur; each nail had 2 holes, and 2 distal locking screws were inserted in each bone, which gave a total number of 54 holes) used a computer-assisted orthopaedic system, the second group (CONTROL GROUP is the same as CAOS group) used Orthofix mechanical targeting device for distal locking. Comparison between 2 groups was made in radiation exposure time, operating time, percentage of correctly placed screws.</p><p><b>RESULTS</b>CAOS group: operating time was (4.44 +/- 2.99) min; radiation exposure time was (1.16 +/- 0.38) min; correctly placed screws rate was (100 +/- 0)%.</p><p><b>CONTROL GROUP</b>operating time was (10.42 +/- 4.18) min; radiation exposure time was (4.71 +/- 3.86) min; correctly placed screws rate was (94.44 +/- 0.36)%. Operating time and radiation exposure time in CAOS group were significantly shorter than those in control group (P < 0.05), no differences were found between 2 groups in relation to the percentage of correctly placed screws.</p><p><b>CONCLUSIONS</b>By using CAOS system for distal locking of intramedullary nails, the locking holes can be drilled accurately and safely. Radiation exposure significantly reduced.</p>

Computer-assisted full planning system for long bone fracture treatment with intramedullary nailing:an experimental study / 中华创伤骨科杂志

Objective To evaluate the efficacy and clinical feasibility of the computer-assisted full plan- ning system for tibial fracture treatment with intramedullary nailing.Methods After analyzing the functional structure and operative procedures of the system,nine plastic tibia and 12 cadaver lower limbs were used for image mosaicing based on C-arm (PHILIPS BV Libra) fluoroscopic images in the operation room to assess the correctness of the mosaicing and planning algorithms.The plastic tibial model was used for analysis of the mosaicing precision.The cadaver tibial bone was used for reduction experiment with the reduction mechanism to analyze the operation feasi- bility.Results Only 7 to 10 [fluoroscopy time:(19.75?0.61)s] valid C-ann projection images were needed to produce a long bone panorama of the lower limb.The total time for image acquisition and mosaicing was within (4.17?0.86)minutes and the mosaicing precision in the plastic tibial model was (1.26?0.76)mm.The opera- tion of the reduction mechanism was very simple and could be controlled by a surgeon automatically or free of hand. An integrated reduction strategy could be produced for rough positioning in general and elaborate operations in de- tails.Conclusion The computer-assisted full planning system can be used for anatomical analysis based on the C-arm panorama,full surgical planning,virtual simulation,selection of proper intramedullary nails and fracture reduction in treatment of long bone fractures.

Surgical treatment of shotgun injuries of the sciatic nerve / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the clinical characteristics and the effect of surgical therapy for shotgun injuries of the sciatic nerve.</p><p><b>METHODS</b>From 1996 to 2000, 19 sciatic nerve injuries resulted from shotgun were observed. Among 19 cases of shotgun sciatic nerve wounds, the gluteal wound was in 2 cases, thigh wound in 15 cases, and knee wound in 2 cases. The firing distance was between 0.5-9 m. According to Shermen classification of shotgun injury, 4 cases belonged to type I injury, 11 cases type II, 4 cases type III. The time from injury to admission was between 2 months-14 months except 1 patient who underwent emergency operation 4 hours after injury, and 1 patient was treated with debridement and epineurial neurorrhaphy, 7 cases with nerve trunk grafting, 6 cases with nerve cable grafting, 4 cases with neurolysis, 1 case with arthrodesis of ankle.</p><p><b>RESULTS</b>Nineteen cases were followed-up for 0.8-3.5 years (mean, 19 months). The excellent and good nerve functional recovery was found in 52.6% according to MCRR.</p><p><b>CONCLUSIONS</b>Shotgun injuries of the sciatic nerve are very severe and complicated, and injuries in most patients were usually complicated by open fracture, vascular injury, soft-tissue loss and infection; the character of nerve injury was classified as 4-5 degree according to Sunderland Standard, nerve transfer is effective in the treatment of shotgun injuries of the sciatic nerve, but outcome is poor; the recovery of the sciatic nerve should be observed continually after injury; selecting correct initial treatment after injury, strict minimally invasive surgical procedure, physical therapy and reasonable preoperative and postoperative medication can improve the surgical results.</p>