Browsing by Author "Khandha, Ashutosh"
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Item Knee gait mechanics and cartilage stress in those with/without medial compartment knee osteoarthritis five years after anterior cruciate ligament reconstruction(University of Delaware, 2016) Khandha, AshutoshPremature knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) surgery is a growing concern. Aberrant knee gait mechanics and joint loads are thought to affect cartilage stress distribution and the incidence of knee OA after ACLR. Knee OA occurs more frequently in the medial compartment, compared to the lateral compartment. All subjects with medial compartment knee OA demonstrate a radiographic osteophyte near the medial joint margin. However, not all subjects get knee OA five years after ACLR. Comparing knee gait mechanics and joint loads in subjects with and without knee OA may be key in establishing rehabilitation and treatment strategies to delay the progression of the disease. The first question this proposal evaluates is “what are the differences in knee gait mechanics and joint loads in those with/without medial compartment knee OA after ACLR, and when are these differences present?” To that end, knee OA was evaluated five years after ACLR, while knee gait mechanics and joint loads were evaluated at multiple time points, i.e. before ACLR, six months, one year and five years after ACLR. All parameters were evaluated at the first peak of vertical ground reaction force during the stance phase of gait. Gait analysis and electromyography (EMG)-informed neuromusculoskeletal (NMS) modeling methods were used for this aim. Six months after ACLR, subjects with knee OA demonstrated inter-limb differences in flexion angle/moment, adduction moment and joint loads, with lower values for the involved knee, compared to the uninvolved knee. These inter-limb differences ceased to exist at later time points. These results indicate that an initial period of under-loading of the involved knee is followed by an extended period of symmetrical loading, in subjects who get medial compartment knee OA five years after ACLR. For the involved knee, five years after ACLR, subjects with knee OA demonstrated lower values for flexion angle/moment, higher value for adduction moment (not statistically significant, but with large effect size) and similar joint loads, compared to subjects without knee OA. These results indicate that while both groups show inter-limb symmetry five years after ACLR, knee gait mechanics are different between these groups. Hence, the uninvolved knee (of subjects with knee OA in the involved knee) may also be at risk of developing knee OA at future time points. The second question this proposal evaluates is “how is cartilage stress distribution near the medial joint margin (region of radiographic osteophyte, under the medial meniscus) affected due to knee gait mechanics and joint loading, in those with/without medial compartment knee OA after ACLR?” Utilizing a combination of knee gait mechanics, joint load and load distribution between deformable knee joint structures is necessary to estimate cartilage stress distribution. Hence, finite element (FE) modeling was used for this aim. Medial tibial cartilage stresses were evaluated at multiple time points, i.e. six months, one year and five years after ACLR, using knee gait mechanics and joint loads from the first aim as inputs. For the involved knee, five years after surgery, subjects with knee OA demonstrated higher values for peak effective stress in the region near the medial joint margin. These results show that stresses are indeed higher in the region where radiographic osteophytes are observed five years after ACLR in subjects with knee OA, compared to subjects without knee OA. These results help to reinforce the link between altered gait and knee OA. The third question this proposal explores is “how soon can changes in cartilage tissue be detected, and is there a relation between joint loading and cartilage tissue level changes?” For inter-limb differences in subjects who get medial compartment knee OA five years after ACLR, evidence of under-loading was present at early time points (six months) after ACLR. Also, cartilage tissue level changes, which may be present at early time points after ACLR, would precede the appearance of radiographic osteophytes. To explore the changes in cartilage at early time points, T2 maps (using quantitative magnetic resonance imaging, or qMRI) were established for two additional subjects, one with evidence of under-loading in the involved knee, and one with symmetric loading. Both subjects had completed gait analysis one year after ACLR. The subject with under-loading of the involved knee did demonstrate higher T2 values (indicative of potential collagen matrix degradation) in the involved knee, compared to the uninvolved knee, and also greater inter-limb differences, compared to the subject with symmetric loading. These results, while from a very small number of subjects, warrant further investigation to establish or reject a potential correlation between early inter-limb loading differences and early cartilage tissue level changes. The sooner that the presence of OA related changes is detected, either directly or indirectly, the greater the potential for intervention to delay the progression of OA. Future studies that implement a combination of the above methodologies (NMS + FE + qMRI) can aid in early detection, prediction and treatment of knee OA.Item Knee joint biomechanics during gait improve from 3 to 6 months after anterior cruciate ligament reconstruction(Journal of Orthopaedic Research, 2022-01-06) Neal, Kelsey; Williams, Jack R.; Alfayyadh, Abdulmajeed; Capin, Jacob J.; Khandha, Ashutosh; Manal, Kurt; Snyder‐Mackler, Lynn; Buchanan, Thomas S.Gait alterations after anterior cruciate ligament reconstruction (ACLR) are commonly reported and have been linked to posttraumatic osteoarthritis development. While knee gait alterations have been studied at several time points after ACLR, little is known about how these biomechanical variables change earlier than 6 months after surgery, nor is much known about how they differ over the entire stance phase of gait. The purpose of this study was to examine knee gait biomechanical variables over their entire movement pattern through stance at both 3 and 6 months after ACLR and to study the progression of interlimb asymmetry between the two postoperative time points. Thirty-five individuals underwent motion analysis during overground walking 3 (3.2 ± 0.5) and 6 (6.4 ± 0.7) months after ACLR. Knee biomechanical variables were compared between limbs and across time points through 100% of stance using statistical parametric mapping; this included a 2 × 2 (Limb × Time) repeated measures analysis of variance and two-tailed t-tests. Smaller knee joint angles, moments, extensor forces, and medial compartment forces were present in the involved versus uninvolved limb. Interlimb asymmetries were present at both time points but were less prevalent at 6 months. The uninvolved limb's biomechanical variables stayed relatively consistent over time, while the involved limb's trended toward that of the uninvolved limb. Statement of Clinical Significance: Interventions to correct asymmetrical gait patterns after ACLR may need to occur early after surgery and may need to focus on multiple parts of stance phase.Item Orthopaedics and Biomedical Engineering Design: An Innovative Duet toward a Better Tomorrow(Journal of the Pediatric Orthopaedic Society of North America, 2023-05-01) Su, Alvin W.; Khandha, Ashutosh; Bansal, Sonia; Ty, Jennifer M.; Baldys, Andrew; French, Zachary P.; Puccinelli, John P.The main purpose of this article is to explore the benefits and dynamics of collaborations between orthopaedic surgeons and biomedical engineering (BME) undergraduates and faculties in the context of engineering design programs as well as clinical immersion programs. An outline of strategies to navigate the seemingly complex landscape of hospitals and universities is presented through models of orthopedic-BME collaborations at two distinct academic practice settings in the United States. In addition to (four) examples of BME design projects sponsored by the clinicians, funding and intellectual property (IP), priority of time management, as well as the positive impact on student education are also discussed. Design collaborations can provide unique educational and research opportunities for the development of undergraduate engineering students to become future leaders; at the same time, this simultaneously facilitates innovative solutions fulfilling unmet clinical needs for orthopedic clinicians. Overall, we hope to provide references and resources for those who are interested in developing similar orthopedic-BME design framework for future innovation and student education in real-life orthopedic research translation.