bluuebunny/crossref_metadata_2025_split huggingface dataset:
Knee Periprosthetic Infections: CAOS Use in One Stage Procedures
Authors: Gérard Giordano 
Published: February 2018

INTRODUCTIONThe results of TKA revisions are less good than a primary TKA (1). The TKA revision frequency increases and we must prepare the next standard of these surgeries (4).The aim of this study was to evaluate the CAOS / one stage strategy to treat the knee PJIs (2, 3).MATERIALSIn this prospective study, between September 2011 and december 2014, 41 patients treated for chronic knee PJI in a one stage revision. An imageless CAOS system (ExactechGPS, Blue-Ortho, Gieres) was used with a personnalized profile. All surgeries were performed with the same protocole and by using the same Optetrak CC knee components (Exactech, Gainesville, FL). All operations were performed by a single senior surgeon.Indications for the revision TKA were (1) revision of a primary TKA or unicondylar knee arthroplasty (n=27) or (2) revision of revisionTKA (n=15).The measurement of the HKA angle, the Oxford score and the ROM were evaluated pre and post-operatively.RESULTS27 males and 14 females with an average age of 71 years old (55-87) were treated for a PIJ (1 unicompartimental prosthesis, 26 TKA and 15 RTKA). The mean follow-up was 41 months (30 months - 6 years). The average time of surgery was 135 mn (120-195) for an average hospitalisation duration of 10 days (7-16). No postoperative outliers were reported (mean preop.: -1,6°+/_-5,1° - Post-op. -0,3°+/_ -1,4°). The average ROM were 115° (90-130°) (Fig. 1). The rate of success for the infection was 92,7%. We report no specific CAS complications and all the navigations were finalized. In this series of complex cases, the rate of infection healing is 92,7%.DISCUSSIONUsing CAOS is a safe option with no specific complication. Combined with one stage procedures, it should be a optimal medicoeconomical strategy for Knee revisions.This first series initiated the « GPS RTKA » project to create a dedicated software evaluated since January 2016 with immediate very good functional results and no complications.2002;(404): 7-13
Computer navigated reduction of scaphoid non-unions and displaced scaphoid fractures- a cadaveric study
Authors: Mak Michael Chu-Kay , Chui Elvis Chun-Sing , Tse Wing-Lim , Ho Pak-Cheong 
Published: February 2018

IntroductionScaphoid non-union results the typical humpback deformity, pronation of the distal fragment, and a bone defect in the non-union site with shortening. Bone grafting, whether open or arthroscopic, relies on fluoroscopic and direct visual assessment of reduction. However, because of the bone defect and irregular geometry, it is difficult to determine the precise width of the bone gap and restore the original bone length, and to correct interfragmentary rotation. Correction of alignment can be performed by computer-assisted planning and intraoperative guidance. The use of computer navigation in guiding reduction in scaphoid non-unions and displaced fractures have not been reported.ObjectiveWe propose a method of anatomical reconstruction in scaphoid non-union by computer-assisted preoperative planning combined with intraoperative computer navigation. This could be done in conjunction with a minimally invasive, arthroscopic bone grafting technique.MethodsA model consisting of a scaphoid bone with a simulated fracture, a forearm model, and an attached patient tracker was used. 2 titanium K-wires were inserted into the distal scaphoid fragment. 3D images were acquired and matched to those from a computed tomography (CT) scan. In an image processing software, the non-union was reduced and pin tracts were planned into the proximal fragment. The K-wires were driven into the proximal fragment under computer navigation. Reduction was assessed by direct measurement.These steps were repeated in a cadaveric upper limb. A scaphoid fracture was created and a patient tracker was inserted into the radial shaft. A post-fixation CT was obtained to assess reduction.Results and DiscussionIn both models, satisfactory alignment was obtained. There were minimal displacement and articular stepping, and scaphoid length was restored with less than 1mm discrepancy. This study demonstrated that an accurate reduction of the scaphoid in non-unions and displaced fractures can be accurately performed using computed navigation and computer-assisted planning. It is the first report on the use of computer navigation in correction of alignment in the wrist.
Accuracy investigation of dual mode markers for navigated dental implant surgery with a new 3D realtime navigation system DENACAM
Authors: Hemm Simone , Böhringer Stephan , Garnier Quentin , Breitenstein Michael , Minonzio Claudio , Berlinghoff Frank , Jürgens Philipp , Schkommodau Erik 
Published: February 2018

Dental implants are in 96% positioned free hand including a risk of suboptimal placement. A miniaturized navigation system has been developed to overcome these limitations by fixing two stereo cameras to the drill to guide the surgeon during implant insertion. The aim of the present study was to develop and analyse a dual-mode marker with a highly precise, high contrast optical pattern, visible by the camera system, on a precise substrate clearly identifiable on Cone Beam CT (CBCT) images and sterilisable. The marker was developed with a laser engraved optical pattern brought to a ceramic substrate containing two holes to ensure clear identification of the position of the marker within CBCT images.The substrate dimensions were verified with a micrometer gauge and compared to the expected tolerances. The position and angular error of the optical pattern on the substrate was analysed on optical microscope images. Six markers were exposed to 20 cleaning and steam sterilization cycles and changes were analysed on optical and scanning electron microscope (SEM) images. Energy dispersive X-ray spectroscopy (EDX) analysis was performed to study the percentage composition of the different elements.Substrate dimensions and angular errors remained always within the defined tolerances. Positioning errors were higher than the tolerances for some of the measurements. The error distribution indicates a systematic error. Results were reproducible over the samples. No changes could be observed visually on the optical microscope images between the initial marker and the 20th sterilization cycle. EDX results show slight percentage variations of the different elements between the different cycles. Fluctuations were most important for the carbon-content.A dual mode marker could be developed with a very accurate optical pattern very precisely positioned on a ceramic substrate making any marker calibration procedure un- necessary. Precision analysis confirmed a reproducible position of the pattern on the substrate, indicating a stable and robust process. Systematic errors can be corrected directly at the used Laser system. Cleaning and sterilization tests confirmed the stability of the dual-mode marker after cleaning and sterilization. The present study has shown that highly accurate, high contrast and robust markers can be manufactured using laser- engraving technology on ceramic substrates.
Design of Flexible Implants for Preservation of Physiological Mobility Exploiting Additive Manufacturing
Authors: Kimm Martin , Jauer Lucas , Hinke Christian , Schleifenbaum Johannes Henrich , Poprawe Reinhart 
Published: February 2018

Due to tumors or bone fractures caused by high mechanical impact, the affected tissue has to be removed. The implantation of a stabilizing replacement is a common solution for defect bridging and support of bone ossification. Preserving the physiological mobility after the treatment could prevent stress shielding or overload of the surrounding muscles and ligaments. [1]In case of a critical vertebral body defect, the body and its attached disks have to be removed. Thereafter the adjacent vertebral bodies are braced together resulting in limited physiological spine movability. A flexible implant adapted to and preserving the patient-specific physiological spine mobility would be a desirable solution. [2] [3]To realize such an implant additive manufacturing (AM) can be used as a key technology. AM offers the following advantages: The build-up of almost any desired complex geometry shape, without additional costs. A monolithic geometry with enhanced functionalities combined in only one part and one material. A cost-efficient implant individualization based on patient specific requirements. [4]Relating to flexibility, the integration of solid state hinges tailored to the patient specific physiological mobility is possible. Hereby, assembly work is neglectable and abrasion will be prevented due to the absence of friction partners. A challenge to overcome will be the durability of the design. It is limited by the fatigue of the material caused by implant motion.
Change in pelvic sagittal tilt after corrective long fusion of spine
Authors: Tamura Kazunori , Hamada Hidetoshi , Takao Masaki , Sakai Takashi , Kaito Takashi , Sugano Nobuhiko 
Published: February 2018

The individual pelvic sagittal inclination (PSI) is an issue for cup alignment in total hip arthroplasty (THA). The pelvic position in supine or functional pelvic plane in supine have been recommended by many reports while some consider a standing pelvic position as the reference to aim an optimal cup alignment. PSI changes in various postures and even in the same posture, aging change it due to spinal degeneration and muscle weakness. The chronological PSI change is larger in standing than that in supine. It is expected that PSI in standing position may improve when spinal long fusion was performed.Therefore, the purpose of this study was to evaluate the change of PSI between pre- and post- corrective long fusion for adult spinal deformity (ASD). Total eight patients underwent corrective surgery for ASD between May 2014 and October 2016 were the subjects of this study. All are females with the average age of 70 years. There were two cases that underwent bilateral THA before spine surgery. The anterior pelvic plane (APP) through the most anterior aspect of the pubic tubercle and bilateral anterior superior iliac spines (ASISs) was used to measure PSI, which was defined as the angle between the APP and the vertical axis on the sagittal plane DRR. In addition, we measured the cup anteversion in two THA cases by using viewer software. The mean change in the preoperative PSI from supine to standing was 17° posteriorly. The mean change in the supine PSI from pre- to post-operation was 6.9° anteriorly, and that in the standing PSI was 17° anteriorly. The mean change in the postoperative PSI from supine to standing was 6.7° posteriorly. When we measured PSI on standard AP radiographs of the pelvis in two patients who underwent THA, the mean change in postoperative PSI from supine to standing was less than 3°.The mean change in cup anteversion on supine AP radiographs were 2.7°. As we expected, the change in PSI from supine to standing position was reduced by performing corrective surgery. In this study, the mean change of radiographic cup anteversion in supine after corrective long fusion was 2.7°and PSI in standing changed into the direction which reduce posterior impingement and anterior dislocation. Although the change in PSI after corrective spine surgery heavily depends on the spine surgeon’s philosophy of correction, corrective spine surgery should have a positive effect on cup alignment in standing and little influence on cup alignment in supine.
Patient-Specific Templates for Pedicle Screw Insertion in Spinal Fixation Surgery
Authors: Hafez Mahmoud , Fouda Mohamed 
Published: February 2018

The increased use of pedicle screws in scoliosis creates a challenge for accurate and safe placement ofscrew within the pedicle during the scoliosis surgery. Patient-specific templates (PST) is a novelmethod to guide the surgeons for allocating and detecting the positions and trajectories of pediclescrews in scoliosis surgery. Based on CT-scans and according to certain protocol, this technique willallow the surgeon to construct a 3D model of spine and present the stage and vertebrae which containthe most deformed bone. With preplanned surgery on specific software, we can develop an accurateand safe position of pedicle screws and its trajectories. This method has the ability to customize theplacement and the size of each pedicle screw based on the unique morphology and landmarks of thevertebrae.
A novel method for defining ligament characteristics in subject specific dynamic surgical planning
Authors: Theodore Willy , Little Joseph , Liu David , Bare Jonathan , Dickison David , Taylor Mark , Miles Brad 
Published: February 2018

Despite of the high success of TKA, 20% of recipients remain dissatisfied with their surgery. There is an increasing discordance in the literature on what is an optimal goal for component alignment. Furthermore, the unique patient specific anatomical characteristics will also play a role. The dynamic characteristics of a TKR is a product of the complex interaction between a patient’s individual anatomical characteristics and the specific alignment of the components in that patient knee joint. These interactions can be better understood with computational models. Our objective was to characterise ligament characteristics by measuring knee joint laxity with functional radiograph and with the aid of a computational model and an optimisation study to estimate the subject specific free length of the ligaments.Pre-operative CT and functional radiographs, varus and valgus stressed X-rays assessing the collateral ligaments, were captured for 10 patients. CT scan was segmented and 3D-2D pose estimation was performed against the radiographs. Patient specific tibio-femoral joint computational model was created. The model was virtually positioned to the functional radiograph positions to simulate the boundary conditions when the knee is stressed. The model was simulated to achieve static equilibrium. Optimisation was done on ligament free length and a scaling coefficient, flexion factor, to consider the ligaments wrapping behaviour.Our findings show the generic values for reference strain differ significantly from reference strains calculated from the optimised ligament parameters, up to 35% as percentage strain. There was also a wide variation in the reference strain values between subjects and ligaments, with a range of 37% strain between subjects. Additionally, the knee laxity recorded clinically shows a large variation between patients and it appears to be divorced from coronal alignment measured in CT. This suggest the ligaments characteristics vary widely between subjects and non-functional imaging is insufficient to determine its characteristics. These large variations necessitates a subject-specific approach when creating knee computational models and functional radiographs may be a viable method to characterise patient specific ligaments.
Pedicle screw insertion in spine: a randomized controlled study for robot-assisted spinal surgery
Authors: Tian Wei , Fan Mingxing , Liu Yajun 
Published: February 2018

To introduce a new robot-assisted surgical system for spinal posterior fixation which called TiRobot, based on intraoperative three-dimensional images. TiRobot has three components: the planning and navigation system, optical tracking system and robotic arm system. By combining navigation and robot techniques, TiRobot can guide the screw trajectories for orthopedic surgeries.In this randomized controlled study approved by the Ethics Committee, 40 patients were involved and all has been fully informed and sign the informed consent. 17 patients were treated by free-hand fluoroscopy-guided surgery, and 23 patients were treated by robot-assisted spinal surgery.A total of 190 pedicle screws was implanted. The overall operation time were not different for both groups. None of the screws necessitated re-surgery for revised placement. In the robot-assisted group, assessment of pedicle screw accuracy showed that 102 of 102 screws (100%) were safely placed (&lt;2 mm, category A+B). And mean deviation in entry point was 1.70 +/- 0.83mm, mean deviation in end point was 1.84 +/- 1.04mm. In the conventional freehand group, assessment of pedicle screw accuracy showed that 87 of 88 (98.9%) were safely placed (&lt;2 mm, category A+B), 1 screw fall in category C, mean deviation in entry point was 3.73 +/- 2.28mm, mean deviation in end point was 4.11 +/- 2.31mm.This randomized controlled study verified that robot-assisted pedicle screw placement with real-time navigation is a more accuracy and safer method, also revealed great clinical potential of robot-assisted surgery in the future.
Margin quality and local recurrence with Patient specific instruments for bone tumor resection
Authors: Paul Laurent , Schubert Thomas , Evrard Robin , Docquier Pierre-Louis 
Published: February 2018

Bone tumor resection and subsequent reconstruction remains challenging for the surgeon. Obtaining adequate margins is mandatory to decrease the risk of local recurrence. Improving surgical margins quality without excessive resection, reducing surgical time and increasing the quality of the reconstruction are the main goals of today’s research in bone tumor surgical management. With the outstanding improvements in imaging and computerized planning, it is now a standard. However, surgical accuracy is essential in orthopaedic oncologic surgery (Grimmer 2005).Patient specific instruments (PSI) may greatly improve the surgeon's ability to achieve the targeted resection. Thanks to its physical support, PSI can physically guide the blade yielding to a better control over the cutting process (Wong, 2014). Surgical time might significantly be reduced as well when compared to conventional method or navigated procedure. Finally, reconstruction may gain in rapidity and quality especially when allograft is the preferred solution as PSI can be designed as well for allograft cutting (Bellanova, 2013).Since 2011, PSI have systematically been used in our institution for bone tumor resection and when applicable allograft reconstruction. This paper reports the mid- to long-term medical outcomes on a large series.
Individual Cooling and Compression System for Accelerated Swelling Reduction on Fractures
Authors: Paessler Annekathrin , Fielitz Markus , Rathmann Heiko , Andrusch Konstantin , Nagel Thomas , Lienig Jens 
Published: February 2018

After a fracture injury a swelling of the skin soft tissue results which prevents an early operation. In order to shorten the waiting time until the decrease of the swelling, the metabolism-reducing effect of mild local hypothermia and the swelling-reducing effect of compression therapy should be used in a device anatomically adjusted to the patient. For the best possible treatment, a regulation of the cooling and compression parameters should be carried out by means of sensor technology in order to allow an adaptation to the individual patient.After a fracture injury a swelling of the skin soft tissue results which prevents an early operation. In order to shorten the waiting time until the decrease of the swelling, the metabolism-reducing effect of mild local hypothermia and the swelling-reducing effect of compression therapy should be used in a device anatomically adjusted to the patient. For the best possible treatment, a regulation of the cooling and compression parameters should be carried out by means of sensor technology in order to allow an adaptation to the individual patient.Based on medical studies, parameter areas relevant to patients could be determined. These were implemented in first functional models for a cooling system and a compression system. Anatomically adapted cooling and pressure chambers allow a good physical coupling of the system to humans. The first test results, considering the heat emission and the skin elasticity properties of the human body, show that both rapid cooling can be achieved in a range of between 17 and 20°C of skin temperature within 4 min, and that under a pressure effect of between 10 and 20 kPa in the pressure chambers a pressure on the human tissue can be produced up to 15 kPa. The cooling system based on Peltier elements is capable of transporting a heat flow up to 10 W. The quiet, maintenance-free Peltier elements also increase the patient's acceptance. In the pressure chambers, a temporally overlapping generation of pressure pulses can imitate the process of natural walking by the effect of muscle pumps and contribute to a technical lymphatic drainage. By detecting the inflammation area with the aid of netlike-arranged temperature sensors and measuring the internal pressure of the pressure chambers in the case of a swelling tissue, cooling can be carried out at a determined point and the occurrence of, for example, a compartment syndrome can be prevented by regulating the pressure.At present still ongoing, promising developments of models for the consideration of the temperature distribution and pressure differences in the cardiovascular system should enable a determination of optimized cooling and pressure curves adapted to the individual human. In this way, the best possible control circuits should be identified using medical expert knowledge.
Robotic-Arm Assisted Total Knee Arthroplasty Demonstrated Greater Accuracy to Plan Compared to Manual Technique
Authors: Hampp Emily , Scholl Laura , Prieto Michael , Chang Ta-Cheng , Abbasi Abdullah , Bhowmik-Stoker Manoshi , Jacofsky David , Mont Michael , Otto Jason 
Published: February 2018

While total knee arthroplasty has demonstrated clinical success, final bone cut and final component alignment can be critical for achieving a desired overall limb alignment. This cadaver study investigated whether robotic-arm assisted total knee arthroplasty (RATKA) allows for accurate bone cuts and component position to plan, compared to manual technique. Six cadaveric specimens (12 knees) were prepared by an experienced user of manual total knee arthroplasty (MTKA), who was inexperienced in RATKA. For each cadaveric pair, a RATKA was prepared on the right leg and a MTKA was prepared on the left leg. Final bone cuts and final component position to plan were measured relative to fiducials, and mean and standard deviations were compared.Measurements of final bone cut error for each cut show that RATKA had greater accuracy and precision to plan for femoral anterior internal/external (0.8±0.5° vs. 2.7±1.9°) and flexion/extension* (0.5±0.4° vs. 4.3±2.3°), anterior chamfer varus/valgus* (0.5±0.1° vs. 4.1±2.2°) and flexion/extension (0.3±0.2° vs. 1.9±1.0°), distal varus/valgus (0.5±0.3° vs. 2.5±1.6°) and flexion/extension (0.8±0.5° vs. 1.1±1.1°), posterior chamfer varus/valgus* (1.3±0.4° vs. 2.8±2.0°) and flexion/extension (0.8±0.5° vs. 1.4±1.6°), posterior internal/external* (1.1±0.6° vs. 2.8±1.6°) and flexion/extension (0.7±0.6° vs. 3.7±4.0°), and tibial varus/valgus* (0.6±0.3° vs. 1.3±0.7°) rotations, compared to MTKA, respectively (where * indicates a significant difference between the two operative methods based on 2-Variances testing, with α at 0.05). Measurements of final component position error show that RATKA had greater accuracy and precision to plan for femoral varus/valgus* (0.6±0.3° vs. 3.0±1.4°), flexion/extension* (0.6±0.5° vs. 3.0±2.1°), internal/external (0.8±0.5° vs. 2.6±1.6°), and tibial varus/valgus (0.7±0.4° vs. 1.1±0.8°) than the MTKA control, respectively.In general, RATKA demonstrated greater accuracy and precision of bone cuts and component placement to plan, compared to MTKA in this cadaveric study. For further confirmation, RATKA accuracy of component placement should be investigated in a clinical setting.