Browsing by Author "Utturkar, Gangadhar M"

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    In vivo cartilage strain increases following medial meniscal tear and correlates with synovial fluid matrix metalloproteinase activity
    (JOURNAL OF BIOMECHANICS, 2015-06-01) Carter, Teralyn E; Taylor, Kevin A; Spritzer, Charles E; Utturkar, Gangadhar M; Taylor, Dean C; Moorman, Claude T; Garrett, William E; Guilak, Farshid; McNulty, Amy L; DeFrate, Louis E
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    Initial displacement of the intra-articular surface after articular fracture correlates with PTA in C57BL/6 mice but not "superhealer" MRL/MpJ mice.
    (Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2021-09) Vovos, Tyler J; Furman, Bridgette D; Huebner, Janet L; Kimmerling, Kelly A; Utturkar, Gangadhar M; Green, Cynthia L; Kraus, Virginia B; Guilak, Farshid; Olson, Steven A
    Posttraumatic arthritis (PTA) occurs commonly after articular fracture and may arise, in part, from joint surface incongruity after injury. MRL/MpJ (MRL) "super-healer" mice are protected from PTA compared to C57BL/6 (B6) mice following articular fracture. However, the relationship between the initial displacement of the articular surface, biologic response, and susceptibility to PTA after fracture remains unclear. The objective of this study was to assess whether joint incongruity after articular fracture, as measured by in vivo micro-computed tomography (microCT), could predict pathomechanisms of PTA in mice. B6 and MRL mice (n = 12/strain) received a closed articular fracture (fx) of the left tibial plateau. Articular incongruity was quantified as bone surface deviations (BSD) for each in vivo microCT scan obtained from pre-fx to 8 weeks post-fx, followed by histologic assessment of arthritis. Serum concentrations of bone formation (PINP) and bone resorption (CTX-I) biomarkers were quantified longitudinally. Both strains showed increases in surface incongruity over time, as measured by increases in BSD. In B6 mice, acute surface incongruity was significantly correlated to the severity of PTA (R 2  = 0.988; p = .0006), but not in MRL mice (R 2  = 0.224; p = .220). PINP concentrations significantly decreased immediately post-fx in B6 mice (p = .023) but not in MRL mice, indicating higher bone synthesis in MRL mice. MRL/MpJ mice demonstrate a unique biologic response to articular fracture such that the observed articular bone surface displacement does not correlate with the severity of subsequent PTA. Clinical Relevance: Identifying therapies to enhance acute biologic repair following articular fracture may mitigate the risk of articular surface displacement for PTA.
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    Quantifying the biochemical state of knee cartilage in response to running using T1rho magnetic resonance imaging.
    (Scientific reports, 2020-02-05) Heckelman, Lauren N; Smith, Wyatt AR; Riofrio, Alexie D; Vinson, Emily N; Collins, Amber T; Gwynn, Olivia R; Utturkar, Gangadhar M; Goode, Adam P; Spritzer, Charles E; DeFrate, Louis E
    Roughly 20% of Americans run annually, yet how this exercise influences knee cartilage health is poorly understood. To address this question, quantitative magnetic resonance imaging (MRI) can be used to infer the biochemical state of cartilage. Specifically, T1rho relaxation times are inversely related to the proteoglycan concentration in cartilage. In this study, T1rho MRI was performed on the dominant knee of eight asymptomatic, male runners before, immediately after, and 24 hours after running 3 and 10 miles. Overall, (mean ± SEM) patellar, tibial, and femoral cartilage T1rho relaxation times significantly decreased immediately after running 3 (65 ± 3 ms to 62 ± 3 ms; p = 0.04) and 10 (69 ± 4 ms to 62 ± 3 ms; p < 0.001) miles. No significant differences between pre-exercise and recovery T1rho values were observed for either distance (3 mile: p = 0.8; 10 mile: p = 0.08). Percent decreases in T1rho relaxation times were significantly larger following 10 mile runs as compared to 3 mile runs (11 ± 1% vs. 4 ± 1%; p = 0.02). This data suggests that alterations to the relative proteoglycan concentration of knee cartilage due to water flow are mitigated within 24 hours of running up to 10 miles. This information may inform safe exercise and recovery protocols in asymptomatic male runners by characterizing running-induced changes in knee cartilage composition.