The Step Holter is a software and mobile application that can be used to easily study gait analysis. The application can be downloaded for free on the App Store and Google Play Store for iOS and Android devices. The software can detect with an easy calibration the three planes to detect the movement of the gait. Before proceeding with the calibration, the smartphone can be placed and fixed with a band or stowed into a long sock with its top edge at the height of the joint line, in the medial side of the tibia. The calibration consists in bending the knee about 20 to 30 degrees and then making a rotation movement, leaving the heel fixed to the ground as a rotation fulcrum. After calibration, the program records data related to lateral flexion, rotation, and bending of the leg. This data can be viewed directly from the smartphone screen or transmitted via a web link to the Step Holter web page The web page allows the users to monitor the test during its execution or view data for tests done previously. By pressing the play button, it is possible to see a simulation of the patient's leg and its movement. With the analyze button, the program is capable of calculating the swing and stance phase of every single step, providing a plot with time and percentages. Finally, with the Get Excel button, test data can be conveniently exported for more in-depth research. The advantage of this application is not only to reduce the costs of a machine for the study of gait analysis but also being able to perform tests quickly, without expensive hardware or software and be used in specific spaces, without specialized personnel. Furthermore, the application can collect important data concerning rotation that cannot be highlighted with the classic gait analysis. The versatility of a smartphone allows tests to be carried out not only during walking but also by climbing or descending stairs or sitting down or getting up from a chair. This software offers the possibility to easily study any kind of patients; Older patients, reluctant to leave their homes for a gait analysis can be tested at home or during an office control visit. Step Holter could be one small step for patients, one giant leap for gait study simplicity. For any figures or tables, please contact authors directly.
Alpha Lipoic Acid (L.A.) is an effective natural antioxidant discovered in the human body in 1951 from L.J. Reed and I.C. Gunslaus from liver. It is inside broccoli, spinach and red meats, especially liver and spleen. Actually it is largely used as antioxidant in antiaging products according to the low toxicity level of the product. The present study take into consideration the possibility to reduce oxidation of medical irradiated UHMWPE GUR 1050, mixing together polyethylene powder and Alpha Lipoic Acid powder. The study is composed of two parts. Part 1 Thermostability of alpha lipoic acid during polyethylene fusion Part 2 detection of oxygen level in artificially aged irradiated polyethylene Solid pieces were made with Gur 1050 powder (Ticona Inc., Bayport, Tex, USA) and mixed with Alpha Lipoic Acid (Talamonti, Italy, Stock 1050919074) 0,1%-‐0,3%-‐0,5%-‐1%-‐2% and gamma ray irradiated with 30 kGy (Isomedix, Northborough, MA). An owen (80° Celsius) was used to produce an aging effect for 35 days in the doped and control samples (Conventional not doped polyethylene). This process simulate an aging effect of 10 years into the human body. Part 1 : THERMAL STABILITY : a Fourier Transfer Infra Red (FTIR) test was made in pieces molded in a cell at 150° and 200°Celsius and pressure of 200 MPa comparing to the UHMWPE powder mixed with alpha lipoic acid. The presence of Alpha Lipoic Acid in the polyethylene was found at any depth in the manufacts. Part 2 : OXIDATION OF THE SURFACE : After 5 weeks at 80° Celsius in a owen (ASTM standard F-‐2003-‐02)A FOURIER TRANSFER INFRA RED TEST (FTIR) was made in the superficial layer and deeper on the undersurface of doped 0,1% and conventional UHMWPE. The antioxidation limit is defined as the ratio of the area under 1740cm/−‐1 carbonyl and 1370 cm/−‐1 Methylene absorbance peaks. In conventional UHMWPE oxidation is detected on the surface and decreases in the deeper layers down to zero under 1500 Micron. In the doped UHMWPE, FTIR demonstrate a very low oxidation limit on the surface and at any depth, comparing to conventional UHMWPE. The examples show that Lipoic Acid is effective as antioxidant in irradiated UHMWPE and it is stable with respect to thermal treatment. For any figures or tables, please contact authors directly.
The aim of this study is to investigate the accuracy and reliability of a Magnetic Resonance Imaging (MRI) based Patient Match Technology (PMT) system (VISIONAIRE, Smith & Nephew, Inc, Memphis, Tenn) by intraoperative use of VectorVision knee navigation software from BrainLAB (Redwood City, California, USA). Between February 2011 and May 2011, 15 patients with primary gonarthrosis were selected for unilateral Total Knee Arthroplasty (TKA). The first three patients were excluded from this study, as they were considered as a warm up to set up the procedure. Therefore 12 patients entered the study. Preoperatively all patient underwent a full-length weight-bearing radiograph in antero-posterior (AP) and a MRI according to the protocol suggested and approved by the manufacturer. All patients were operated with cemented posterior stabilised prosthesis cruciate ligament sacrificing (Journey BCS, Smith & Nephew, Inc, Memphis, Tennessee, USA) by the same surgeon using the VISIONAIRE patient matched cutting jigs. During surgery, once the guides were placed and fixed, the orientation was checked by the navigator. The following parameters were evaluated: size of the implant, alignment in coronal and sagittal plane. An unsatisfactory result was considered an error ≥ 2° in both plane for each component as a possible error of 4° could result in aggregate.Introduction
Methods
The Segond's fracture is described as a cortical avulsion of the lateral tibial plateau at the site of insertion of the middle third of the lateral capsular ligament. The Segond's fracture is usually associated with a tear of the Anterior Cruciate Ligament (ACL) and it is considered as an indirect radiological sign of complete rupture of the ACL. However there are no studies investigating the effect of a Segond's fracture on the kinematic of the knee especially on the rotatory instability and Pivot Shift (PS) phenomenon. The purpose of this study is to investigate the effect of a Segond's fracture on the kinematic of the knee with the use of navigation and the PS test. Ten whole fresh-frozen cadavers were used. A navigator (2.0 Orthopilot Navigation System, BBraun Aesculap, Tuttlingen, Germany) was used to measure maximum manual Anterior Tibial Translation (ATT) at 30°, 60° and 90° of flexion, maximum manual Internal Rotation (IR) and maximum manual External Rotation (ER) at 0°, 15°, 30°, 45° and 90° of flexion. All procedures were performed three times and the mean value taken as the final result in each case. Moreover a PS test was performed by the senior, most experienced, surgeon, and graded as mild (gliding), moderate (jerk) and severe (subluxation). Navigation measurements and PS tests were performed in each knee with ACL intact, after arthroscopic cutting of the entire ACL and after a Segond's fracure was produced by exposing the antero lateral compartment of the knee underneath the ileo-tibial tract. Statistical analysis was performed using ANOVA 1-way and MANOVA tests and value for statistical analysis was set at p<0.05Introduction
Methods
In total knee arthroplasty extramedullary tibial guides could not to be as accurate as requested in obtaining proper alignment perpendicular to the mechanical axis. The aim of this study was to determine the accuracy of an accelerometer-based system (KneeAlign 2; OrthAlign Inc, Aliso Viejo, California) as evaluated by post-op X-rays analysis. Between March 2012 and May 2012 thirty consecutive patients with primary gonarthrosis were selected for unilateral total knee arthroplasty (TKA) using a handheld surgical navigation system to perform the tibial resection.
Postoperatively, standing anteroposterior hip-to-ankle radiographs and lateral knee-to-ankle radiographs were performed to determine the varus/valgus alignment and the posterior slope of the tibial components relative to the mechanical axis in both the coronal and sagittal planes. The difference between the intraoperative reading of the tibial varus/valgus alignment and posterior slope provided by the system was compared to the radiographic measurements obtained postoperatively for each respective case. Differences were analysed via standard t test. The critical level of significance was set at P <0.05.Introduction
Methods
Alpha Lipoic Acid (L.A.) is an effective natural antioxidant discovered in the human body in 1951 from L.J. Reed and I.C. Gunslaus from liver. It is inside broccoli, spinach and red meats, especially liver and spleen. Actually it is largely used as antioxidant in antiaging products according to the low toxicity level of the product. The present study take into consideration the possibility to reduce oxidation of medical irradiated UHMWPE GUR 1050, mixing together polyethylene powder and Alpha Lipoic Acid powder. The study is composed of two parts. Part 1 Thermostability of alpha lipoic acid during polyethylene fusion Part 2 detection of oxygen level in artificially aged irradiated polyethylene Solid pieces were made with Gur 1050 powder (Ticona Inc., Bayport, Tex, USA) and mixed with Alpha Lipoic Acid (Talamonti, Italy, Stock 1050919074) 0, 1% and gamma ray irradiated with 30 kGy (Isomedix, Northborough, MA). An oven (80° Celsius) was used to produce an aging effect for 35 days in the doped and control samples (Conventional not doped polyethylene). This process simulate an aging effect of 10 years into the human body. THERMAL STABILITY: a Fourier Transfer Infra Red (FTIR) test was made in pieces molded in a cell at 150° and 200°Celsius and pressure of 200 MPa comparing to the UHMWPE powder mixed with alpha lipoic acid. The presence of Alpha Lipoic Acid in the polyethylene was found at any depth in the manufacts. figure 1: A Pure Lipoic Acid. B Lipoic Acid + UHMWPE melted 150° C. Lipoic Acid + UHMWPE melted 200° C° (A And B spectra subtracted UHMWPE) OXIDATION: After 5 weeks at 80° Celsius in a oven (ASTM standard F-2003-02)A FOURIER TRANSFER INFRA RED TEST (FTIR) was made in the superficial layer and deeper on the undersurface of doped 0.1% and conventional UHMWPE. The antioxidation limit is defined as the ratio of the area under 1740 cm/−1 carbonyl and 1370 cm/−1 Methylene absorbance peaks. In conventional UHMWPE oxidation is detected on the surface and decreases in the deeper layers down to zero under 1500 Micron Fig 2. figure 2 Pure polyethylene: A Surface, B 1500 Micron, C 3000 Micron In the doped UHMWPE, FTIR demonstrate a very low oxidation limit on the surface and at any depth, comparing to conventional UHMWPE Fig 3. figure 3 Doped UHMWPE A surface, B 700 micron deept, C 1700 micron deept The examples show that Lipoic Acid is effective as antioxidant in irradiated UHMWPE and it is stable with respect to thermal treatment.
