Browsing by Author "Mohtadi, Nicholas"
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- ItemOpen AccessMesenchymal progenitor cells from non-inflamed versus inflamed synovium post-ACL injury present with distinct phenotypes and cartilage regeneration capacity(2023-06-25) Krawetz, Roman J.; Larijani, Leila; Corpuz, Jessica M.; Ninkovic, Nicoletta; Das, Nabangshu; Olsen, Alexandra; Mohtadi, Nicholas; Rezansoff, Alexander; Dufour, AntoineAbstract Background Osteoarthritis (OA) is a chronic debilitating disease impacting a significant percentage of the global population. While there are numerous surgical and non-invasive interventions that can postpone joint replacement, there are no current treatments which can reverse the joint damage occurring during the pathogenesis of the disease. While many groups are investigating the use of stem cell therapies in the treatment of OA, we still don’t have a clear understanding of the role of these cells in the body, including heterogeneity of tissue resident adult mesenchymal progenitor cells (MPCs). Methods In the current study, we examined MPCs from the synovium and individuals with or without a traumatic knee joint injury and explored the chondrogenic differentiation capacity of these MPCs in vitro and in vivo. Results We found that there is heterogeneity of MPCs with the adult synovium and distinct sub-populations of MPCs and the abundancy of these sub-populations change with joint injury. Furthermore, only some of these sub-populations have the ability to effect cartilage repair in vivo. Using an unbiased proteomics approach, we were able to identify cell surface markers that identify this pro-chondrogenic MPC population in normal and injured joints, specifically CD82LowCD59+ synovial MPCs have robust cartilage regenerative properties in vivo. Conclusions The results of this study clearly show that cells within the adult human joint can impact cartilage repair and that these sub-populations exist within joints that have undergone a traumatic joint injury. Therefore, these populations can be exploited for the treatment of cartilage injuries and OA in future clinical trials.
- ItemOpen AccessPrevalence and Factors Associated with Femoroacetabular Impingement Syndrome Among Youth Ice Hockey and Ringette Players(2024-04-29) Martin, Maitland; Emery, Carolyn; Schneider, Geoff; Bullock, Garrett S.; Mohtadi, Nicholas; Dijkstra, PaulHigh impact sports lead to intense stress and wear on weight bearing joints such as the knee, hip, or ankle, potentially resulting in trauma to the joints. Ice hockey is one such sport and has been shown to be a risk factor for hip and groin problems in athletes, in particular, femoroacetabular impingement (FAI) syndrome. In this thesis, a systematic review of the literature is used to examine prevalence of FAI syndrome and methods of clinical and radiological assessment in adolescent athletes (aged 10-19) compared to young adult athletes (aged 20-35) in all sports. A screening protocol for suspected FAI syndrome was developed to examine the prevalence of signs and symptoms associated with FAI syndrome and was examined for intra -and inter-rater reliability. A cross-sectional study design was utilized to examine the presence of signs and symptoms associated with FAI syndrome in ice hockey and ringette athletes aged 14-24. In addition to completion of the hip screening protocol, participants completed a focused hip history questionnaire, the International Hip Outcome (iHOT-33) Tool, and preseason baseline questionnaires (PBQs). Data were collected for 270 participants (166 males, 104 females), and findings indicated a high prevalence of suspected FAI syndrome (signs and symptoms) in this sample. Finally, 28 males and 30 females from the larger sample underwent bilateral hip radiographs (x-rays) for examination of morphologies associated with FAI syndrome and subsequent diagnosis. Findings across all studies demonstrated a high prevalence of signs and symptoms of FAI syndrome and subsequent FAI syndrome diagnosis. Future research should investigate incidence of FAI syndrome in this population and measures for early detection, such as implementation of a screening protocol (secondary prevention), and subsequent development of primary prevention strategies.
- ItemOpen AccessThe Effect of Stochastic Resonance Stimulation on Proprioception and Postural Control in Anterior Cruciate Ligament Reconstructed Patients(2017) Zandiyeh, Payam; Ronsky, Janet; Goldsmith, Peter; Von Tscharner, Vinzenz; Nettel-Aguirre, Alberto; Mohtadi, Nicholas; Ferguson-Pell, MartinThe anterior cruciate ligament (ACL) is one of the most commonly injured ligaments in the knee that frequently results in reconstruction surgery. Some degree of chronic proprioception and postural balance deficiency has been reported following ACL reconstruction (ACLR) surgery, which may be associated with a higher risk of ACL re-injury in these patients. Stochastic resonance (SR) has been shown to improve proprioception in various clinical populations with comparable postural and proprioceptive deficiencies as the ACLR population. In this dissertation, the existence of such deficiencies has been investigated in female ACLR participants and healthy controls. The effect of SR on improving the postural balance and knee proprioception in ACLR and healthy populations has also been studied. The ACLR participants were tested at three months (n = 19) and six months post-surgery (n = 15), while healthy participants were tested once (n = 28). The SR vibration was applied locally to the knee region. Proprioception was evaluated using movement threshold and movement repeatability tests. The effects of the following factors on proprioception were studied: SR (ON vs. OFF), movement direction (flexion vs. extension), and limb condition (ACLR vs. contralateral; ACLR vs. healthy dominant control). Postural balance during single leg standing (duration of 30 sec) was assessed with new measures including entropic half-life (EnHL) and surrogate entropy (ΔE_surr). These measures were developed in conjunction with this dissertation. The effects of the following factors on postural balance were studied: SR (ON vs. OFF), limb side (ACLR vs. contralateral; ACLR vs. healthy dominant control), and vision (eyes open vs. eyes closed). SR vibration successfully improved proprioception in the ACLR and healthy controls. These study results suggest that SR could potentially aid in pre/post-surgery proprioception rehabilitation. This study showed that a postural balance deficiency was present when the ACLR limb was compared to healthy dominant control limbs. When the ACLR limb was compared to the contralateral, the deficiency was only present when the eyes were closed. These findings may suggest that the postural balance deficiency is subtle. Therefore, more stringent or demanding experimental protocols may be necessary to test postural balance in functional groups with deficiencies such as the ACLR group.b