MOCART Score is Not a Feasible Tool for the Assessment of Osteochondral Lesions of the Talus

Category: Ankle, Sports, Radiographic assessment Introduction/Purpose: To evaluate the applicability and reproducibility of the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score for morphological evaluation of osteochondral lesions of the talus (OLT) repaired using the autologous matrix-induced chondrogenesis (AMIC) technique. Methods: Two radiologists (R1-R2) and two orthopaedic surgeons (O1-O2) independently reviewed 26 MRI scans of the ankle performed on 13 patients (6 females, 7 males; age: 38.9±15.9, range 14-63) with OLT repaired using the AMIC technique between November 2011 and July 2015 at our institution. Out of 13, 7 were treated with biomimetic osteochondral scaffold implantation, while 6 were treated with bone-marrow derived cell transplantation. The MRI scans were performed at 6 and 12 months after treatment. For inter- and intra-observer agreement evaluation for each variable of the MOCART score we used Cohen’s kappa coefficient. Progression of MOCART score between 6 and 12 months evaluation was assessed using the Wilcoxon test. Results: The inter-observer agreement between R1-R2 ranged from poor (adhesions, k=0.124) to almost perfect (subchondral bone, k=0.866), while between O1-O2 ranged from absent (effusion, k=-0.190) to poor (surface, k=0.172). The intra-observer agreement of R1 ranged from poor (signal intensity, k=0.031) to substantial (subchondral lamina, k=0.677), while that of O1 ranged from absent (subchondral bone, k=-0.061) to substantial (surface, k=0.663). There was a statistically significant increase of MOCART score between 6-month and 12-month evaluation of R1 (Z=-2.672; P=0.008), R2 (Z=-2.721; P=0.007) and O1 (Z=- 3.034; P=0.002). Conversely, the increase of MOCART score between the 6-months and 12-months evaluation of O2 was not statistically significant (Z=-1.665; P=0.096). Conclusion: MRI certainly has a crucial role in the follow-up of surgical repaired OLT but the MOCART score does not seem to be sufficiently reliable and reproducible to be applied for this purpose

Prevalence and Associated Factors of Severe Disease in an Athletic Population

Category: Hindfoot, Sports, Children Introduction/Purpose: Sever disease is a common cause of pain in growing kids, but there is no consensus among researchers regarding its etiology. Recently several papers studied the role of sport on the physical and the psychological development of the child, including the possibility that these activities can cause overuse injuries in childhood. The purpose of the present study is to identify any association between heel pain due to calcaneal apophysitis and level of sport activity, type of sport, type of terrain, body mass index (BMI) and foot posture. Methods: We studied 430 athletic children in a population-based sample of soccer (29.53%), basketball (48.37%) and volleyball (22.79%) players, aged between 6 and 14 years. Physical examination, Foot Posture Index (FPI), Oxford ankle and foot questionnaire Italian version for children and parents and a custom made questionnaire on sport were collected from each athlete. Diagnosis of Sever disease was made with a positive heel squeeze test. Results: Our data showed that body mass index, sex, type of terrain, type of sport, FPI should not be considered risk factors for calcaneal apophysitis, while exists a statistical significant higher risk for younger age (p < 0.01), lower number of training session/week (p = 0.02) and shorter session (p < 0.01). Conclusion: The prevalence of Severe disease in athletic children in the study sample was higher in younger and low active patients. BMI was not associated with an increased risk neither sport specialization. Investigating association between the type of terrain and Sever disease it does not appear to have a significant role. Analysis of the FPI produced no significant risk factors. The strengths of this study consists in a large population size, all participants underwent clinical assessment, and the use of a detailed, previously validated test, scales and questionnaire

Contact Stresses in a Fixed-Bearing Total Ankle Replacement

Category: Ankle, Ankle Arthritis, Basic Sciences/Biologics Introduction/Purpose: Third-generation ankle implants with good clinical results continued to increase the popularity of total ankle arthroplasty (TAA) to address end-stage ankle osteoarthritis preserving joint movement. Newer TAA used fixed-bearing designs, with a theoretical increase of contact stresses leading to a higher polyethylene wear. The purpose of this study was to investigate the contact stresses in the polyethylene component of a new third-generation TAA, with a fixed-bearing design, using 3D finite element analysis. Methods: A three-dimensional finite element model was developed based on the Zimmer Trabecular Metal Total Ankle (ZTMTA) and a finite element analysis was employed to evaluate the contact pressure, contact area and Von Mises stress in the polyethylene articular surface in the stance phase of the gait cycle. Results: The peak values were found at the anterior regions of the articulating surface, where reached 19.8 MPa at 40% of gait cycle. The average contact pressure during the stance phase of gait was 6.9 MPa. The maximum von Mises stress of 14.1 MPa in the anterior section was reached at 40% of the gait cycle. For the central section the maximum von Mises stress of 10.8 MPa was reached at 37% of the gait cycle, whereas for posterior section the maximum of 5.4 MPa was reached at the end of the stance phase (60% of the gait cycle). Conclusion: Although, the average von Mises stress was less than 10 MPa, high peak pressure values were recorded. Advanced models to quantitatively estimate the wear are needed to assess polyethylene and metal component survivorship