Browsing by Author "Ochocki, Danielle N."

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    Endurance running during late murine adolescence results in a stronger anterior cruciate ligament and flatter posterior tibial slopes compared to controls
    (Springer, 2022-01-03) Ochocki, Danielle N.; Loflin, Benjamin E.; Ahn, Taeyong; Colglazier, Kaitlyn A.; Young, Andrew R.; Snider, Anna A.; Bueckers, Elizabeth P.; Wojtys, Edward M.; Schlecht, Stephen H.; Orthopaedic Surgery, School of Medicine
    Background: Anterior cruciate ligament (ACL) injury rates continue to rise among youth involved in recreational and competitive athletics, requiring a better understanding of how the knee structurally and mechanically responds to activity during musculoskeletal growth. Little is understood about how anatomical risk factors for ACL injury (e.g., small ACL size, narrow intercondylar notch, and steep posterior tibial slope) develop and respond to increased physical activity throughout growth. We hypothesized that the ACL-complex of mice engaged in moderate to strenuous physical activity (i.e., endurance running) throughout late adolescence and young adulthood would positively functionally adapt to repetitive load perturbations. Methods: Female C57BL6/J mice (8 weeks of age) were either provided free access to a standard cage wheel with added resistance (n = 18) or normal cage activity (n = 18), for a duration of 4 weeks. Daily distance ran, weekly body and food weights, and pre- and post-study body composition measures were recorded. At study completion, muscle weights, three-dimensional knee morphology, ACL cross-sectional area, and ACL mechanical properties of runners and nonrunners were quantified. Statistical comparisons between runners and nonrunners were assessed using a two-way analysis of variance and a Tukey multiple comparisons test, with body weight included as a covariate. Results: Runners had larger quadriceps (p = 0.02) and gastrocnemius (p = 0.05) muscles, but smaller hamstring (p = 0.05) muscles, compared to nonrunners. Though there was no significant difference in ACL size (p = 0.24), it was 13% stronger in runners (p = 0.03). Additionally, both the posterior medial and lateral tibial slopes were 1.2 to 2.2 degrees flatter than those of nonrunners (p < 0.01). Conclusions: Positive functional adaptations of the knee joint to moderate to strenuous exercise in inbred mice offers hope that that some anatomical risk factors for ACL injury may be reduced through habitual physical activity. However, confirmation that a similar response to loading occurs in humans is needed.
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    State of the mineralized tissue comprising the femoral ACL enthesis in young women with an ACL failure
    (Wiley, 2021) Patton, Daniella M.; Ochocki, Danielle N.; Martin, Colin T.; Casden, Michael; Jepsen, Karl J.; Ashton-Miller, James A.; Wojtys, Edward M.; Schlecht, Stephen H.; Orthopaedic Surgery, School of Medicine
    Despite poor graft integration among some patients that undergo an ACL reconstruction, there has been little consideration of the bone quality into which the ACL femoral tunnel is drilled and the graft is placed. Bone mineral density of the knee decreases following ACL injury. However, trabecular and cortical architecture differences between injured and non-injured femoral ACL entheses have not been reported. We hypothesize that injured femoral ACL entheses will show significantly less cortical and trabecular mass compared to non-injured controls.Femoral ACL enthesis explants from 54 female patients (13 – 25 years) were collected during ACL reconstructive surgery. Control explants (n = 12) were collected from 7 donors (18 - 36 years). Injured (I) femoral explants differed from those of non-injured (NI) controls with significantly less (p ≤ 0.001) cortical volumetric bone mineral density (vBMD) (NI: 736.1 – 867.6 mg/cc; I: 451.2 – 891.9 mg/cc), relative bone volume (BV/TV) (NI: 0.674 – 0.867; I: 0.401 – 0.792) and porosity (Ct.Po) (NI: 0.133 – 0.326; I: 0.209 – 0.600). Injured explants showed significantly lesstrabecular vBMD (p = 0.013) but not trabecular BV/TV (p = 0.314), thickness (p = 0.412), or separation (p = 0.828). We found significantly less cortical bone within injured femoral entheses compared to non-injured controls.Lower cortical and trabecular bone mass within patient femoral ACL entheses may help explain poor ACL graft osseointegration outcomes in the young and may be a contributor to the osteolytic phenomenon that often occurs within the graft tunnel following ACL reconstruction.