Browsing by Author "Bugajski, Tomasz"
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- ItemOpen AccessThe Application of the Reference Finite Helical Axis for Characterizing Knee Joint Kinematics(2022-01) Bugajski, Tomasz; Ronsky, Janet; Manske, Sarah; Johnston, KellyAltered knee kinematics are an important biomechanical marker for the development of tibiofemoral osteoarthritis (OA). They are associated with altered cartilage contact areas, resulting in forces acting on unadapted cartilage that may degrade over time. The conventional approach to quantify knee kinematics is with Cardan angles, but the uncommon helical axis (HA) approach may provide supplementary information. However, the HA is susceptible to stochastic errors when angular displacements are small. To alleviate this error, a reference position may be used that permits larger angular displacements. However, more assessments are required to determine the utility of this reference finite helical axis (rFHA) method to provide biomechanical markers of tibiofemoral OA. The purpose of this thesis was to technically evaluate the rFHA and demonstrate its ability to distinguish knee kinematics of high tibiofemoral OA risk individuals. Technical evaluations consisted of 1) determining the effect of different smoothing techniques on rFHA accuracy, 2) assessing the sensitivity of the rFHA to reference position misalignments, and 3) comparing rFHA measures between an optical motion camera system (OMCS) and highspeed biplanar videoradiography system (HSBV). The utility of the rFHA was demonstrated by applying it to high tibiofemoral OA risk populations, specifically anterior cruciate ligament repaired (ACLR) knees and older knees. A spline filter with outlier removal process was the top performing smoothing technique for rFHA accuracy, providing a 72.2-80.1% improvement in rotational speed differences. Substantial differences of the rFHA measures were determined with misaligned reference positions, ranging from 1.17-19.53 mm and 0.77-5.45 deg. rFHA measure differences were also found between the OMCS and HSBV, ranging from 10.19-58.03 mm and 3.39-13.63 deg. Finally, kinematic trends were found in ACLR knees during a vertical drop jump, showing greater magnitudes of rFHA dispersion and helical internal rotation than healthy knees (dispersion: 0.46 deg; helical internal rotation: 2.18 deg). Additionally, significantly different rFHA path lengths were found between older and younger asymptomatic knees during walking (10.60 mm, p = 0.01). These findings demonstrate the utility of the rFHA in biomechanics, providing a supplementary method of characterizing knee kinematics and distinguishing the movement patterns of healthy individuals from tibiofemoral OA prone individuals.
- ItemOpen AccessBracing of Pectus Carinatum: A Quantitative Analysis(2017) Bugajski, Tomasz; Ronsky, Janet; Murari, Kartikeya; Lopushinsky, StevenPectus Carinatum (PC) presents as an overgrowth of costal cartilages resulting in a sternal protrusion. Treatment of PC is performed with a pectus carinatum orthosis (PCO) that compresses the protrusion. Injuries may arise when this PCO is over-tightened. For the first time, a force measurement system (FMS) was constructed that measured PCO forces. The purpose of this study was to determine if participants could accurately attain their clinically prescribed force (CF) over time, and if the protrusion stiffness (PS) influences the participant-applied forces (PF) and correction rate (CR). Results demonstrated that most PFs (75%) exceeded their associated CF (0.46-5.01 lbs). Further investigation is required to determine clinical significance. PS had a positive relationship with PF, but no relationship with CR. Future studies focusing on improved displacement measurements would enhance the ability to quantify PS. Developing a FMS to provide real-time feedback should also be considered to improve PCO efficacy.
- ItemOpen AccessReproducibility and repeatability of a semi-automated pipeline to quantify trapeziometacarpal joint angles using dynamic computed tomography(2022-11-08) Kuczynski, Michael T.; Wang, Kendra; Tse, Justin J.; Bugajski, Tomasz; Manske, Sarah L.Abstract Background The trapeziometacarpal (TMC) joint is a mechanically complex joint and is commonly affected by musculoskeletal diseases such as osteoarthritis. Quantifying in vivo TMC joint biomechanics, such as joint angles, with traditional reflective marker-based methods can be difficult due to the joint’s location in the hand. Dynamic computed tomography (CT) can facilitate the quantification of TMC joint motion by continuously capturing three-dimensional volumes over time. However, post-processing of dynamic CT datasets can be time intensive and automated methods are needed to reduce processing times to allow for application to larger clinical studies. The purpose of this work is to introduce a fast, semi-automated pipeline to quantify joint angles from dynamic CT scans of the TMC joint and evaluate the associated error in joint angle and translation computation by means of a reproducibility and repeatability study. Methods Ten cadaveric hands were scanned with dynamic CT using a passive motion device to move thumbs in a radial abduction–adduction motion. Static CT scans and high-resolution peripheral quantitative CT scans were also acquired to generate high-resolution bone meshes. Abduction–adduction, flexion–extension, and axial rotation angles were computed using a joint coordinate system. Reproducibility and repeatability were assessed using intraclass correlation coefficients, Bland–Altman analysis, and root mean square errors. Target registration errors were computed to evaluate errors associated with image registration. Results We found good repeatability for flexion–extension, abduction–adduction, and axial rotation angles. Reproducibility was moderate for all three angles. Joint translations exhibited greater repeatability than reproducibility. Specimens with greater joint degeneration had lower repeatability and reproducibility. We found that the difference in resulting joint angles and translations were likely due to differences in segment coordinate system definition between multiple raters, rather than due to registration errors. Conclusions The proposed semi-automatic processing pipeline was fast, repeatable, and moderately reproducible when quantifying TMC joint angles and translations. This work provides a range of errors for TMC joint angles from dynamic CT scans using manually selected anatomical landmarks.