Preoperative Evaluation and Surgical Simulation for Osteochondritis Dissecans of the Elbow Using Three-Dimensional MRI-CT Image Fusion Images

We used our novel three-dimensional magnetic resonance imaging-computed tomography fusion images (3D MRI-CT fusion images; MCFIs) for detailed preoperative lesion evaluation and surgical simulation in osteochondritis dissecans (OCD) of the elbow. Herein, we introduce our procedure and report the findings of the assessment of its utility. We enrolled 16 men (mean age: 14.0 years) and performed preoperative MRI using 7 kg axial traction with a 3-Tesla imager and CT. Three-dimensional-MRI models of the humerus and articular cartilage and a 3D-CT model of the humerus were constructed. We created MCFIs using both models. We validated the findings obtained from the MCFIs and intraoperative findings using the following items: articular cartilage fissures and defects, articular surface deformities, vertical and horizontal lesion diameters, the International Cartilage Repair Society (ICRS) classification, and surgical procedures. The MCFIs accurately reproduced the lesions and correctly matched the ICRS classification in 93.5% of cases. Surgery was performed as simulated in all cases. Preoperatively measured lesion diameters exhibited no significant differences compared to the intraoperative measurements. MCFIs were useful in the evaluation of OCD lesions and detailed preoperative surgical simulation through accurate reproduction of 3D structural details of the lesions.

BIOMECHANICAL SIMULATION OF RADIAL HEAD SUBLUXATION IN CADAVERIC PEDIATRIC ELBOWS

Background: Radial head subluxation, known as pulled elbow or Nursemaid’s elbow, is a common pediatric condition that occurs when a longitudinal traction force is applied to an elbow that is pronated and extended. Although the stability of the proximal radioulnar joint has been previously examined in cadaveric models, there are no current studies quantifying the biomechanics of nursemaid’s elbow. The purpose of our study was to demonstrate and quantify the axial traction force required to produce a nursemaid’s elbow in a pediatric cadaver specimen. Methods: Two fresh-frozen cadaveric elbows from a single 3 year-old male donor were dissected by a fellowship-trained orthopedic surgeon. An Instron 5944 testing machine with a 2 kN load cell was used to perform uniaxial testing. The radius and humerus were mounted to the Instron machine, and loaded in the axial direction with the elbow in full extension. Loading occurred at a rate of 10 mm/sec for 4 seconds, during which the force and actuator displacement were continuously recorded. The local instantaneous load and extension displacement at the time of subluxation were recorded, and data was synced with high-frame-rate video footage used to confirm the annular ligament subluxation. Results: The load to failure required to produce the nursemaid’s elbow injury in the first elbow was 31N, with a failure displacement of 4.6mm. The second elbow demonstrated a load to failure of 26N, with a failure displacement of 4.6mm. After subluxation, we reduced the annular ligament from the first specimen. The elbow was then re-tested and demonstrated a load to failure of 20N, with a failure displacement of 2.6mm. Conclusion: Axial traction applied to a pediatric cadaver specimen results in subluxation of the annular ligament into the radiocapitellar joint. The mean load to failure is 28.5N, and a lower load to failure was required to produce a recurrent subluxation in a previously injured specimen. Lower load for a recurrent subluxation may be attributed to damage on the annular ligament due to the first subluxation. [Figure: see text]

A boundary value problem of orthotropic electroelastic circular cylinder

A boundary value problem of orthotropic piezoelectric solid circular cylinder which is in the state of antiplane shear deformation is studied. The whole boundary surface is loaded by an equilibrium axial traction. This paper gives an analytical solution of the considered antiplane shear deformation.

DOZ047.36: Thoracoscopic esophageal internal axial traction for long- gap esophageal atresia

Aim of the Study Long-gap esophageal atresia (LGEA) remains a surgical challenge. This study aimed to report the results of thoracoscopic esophageal axial internal traction in LGEA. Methods This multicenter observational study included retrospectively neonates who underwent primary thoracoscopic esophageal axial internal traction for LGEA between June 2017 and July 2018. LGEA was defined as the technical impossibility to perform a primary esophageal anastomosis. The Ethical Review Board of our institution approved the study. Main Results Eight neonates were included with a median gestational age at birth of 35 weeks [25; 37] and a median birth weight of 2266 g [890; 3800], 6 types I and 2 types II according to Ladd's classification. Initial median gap between 2 esophageal ends was 5 vertebral bodies [4.5; 7]. Internal traction was performed at a median age of 5 weeks of life [1; 17] with a median operative time of 87 minutes. Four patients required at least 2 internal traction procedures. After a mean traction time of 1.5 weeks [1; 13.5], esophageal anastomosis was successfully performed in 7 patients (5 thoracoscopies, 2 thoracotomies) with a median operative time of 165 minutes. One patient needed a colonic interposition. Five of these 7 patients required an esophageal endoscopic dilatation (median number: 4 [2; 6]). Median follow-up was 9.75 months [3; 16]. Conclusions Thoracoscopic esophageal axial internal traction for LGEA was a safe and feasible procedure that allowed an esophageal anastomosis in 7 of the 8 patients. Improvement of the procedure requires setting a common protocol concerning the timing of the first internal axial traction and the duration of traction before considering esophageal anastomosis.

Evaluation of articular cartilage injury using computed tomography with axial traction in ankle joint

Category: Ankle Introduction/Purpose: Although chondral or osteochondral injuries are usually assessed by MRI, its accuracy is reportedly low because of the relatively thin cartilage layer and its close apposition to the cartilage talus and tibial plafond. The subchondral bone plays a role in cartilage metabolism, therefore the evaluation of subchondral bone is crucial for cartilage treatment. A method which enables the simultaneous evaluation of cartilage and subchondral bone is useful for the treatment of cartilage injury. The purpose of this study was to assess the feasibility of CT imaging with axial traction for the diagnosis of articular cartilage injuries. Methods: Chondral lesion in 18 ankles of 17 patients were evaluated. These 18 ankles consisted of 11 ankles of osteochondral lesion of the talar dome (OLT), 5 ankles of osteoarthritis of ankle joints and 2 ankles of anterior impingement syndrome. Twelve males and 5 women were included, with a mean age of 33.7 years (range, 15 -70 years). An ankle distractor foot strap was placed on the ankle with 30 degrees flexion of the knee joint, and a traction force of 80 N was applied during CT scanning. Gray scale CT images were allocated colors to make it easier to evaluate the cartilage layer. The international Cartilage Repair Society (ICRS) grades on CT were compared with those in arthroscopic findings. Results: The respective sensitivity and specificity of CT imaging with traction compared to ICRS grading were 74.4%, and 96.3%. The level of agreement of the ICRS grading between CT images and arthroscopic findings showed moderate (kappa coefficient; 0.547). The diagnosis of grade 3 or 4 lesions had 80.0% sensitivity. Axial traction to CT enabled the delineation of the cartilage surface including chondral thinning, defect and cartilage separation more visible (Figure 1). Conclusion: CT with axial traction could obtain acceptable levels of sensitivity and specificity for the evaluation of articular cartilage injuries in addition to the assessment of subchondral bone.