Walking biomechanics of end stage knee OA and TKA patients.

Osteoarthritis (OA) of the knee is associated with decline in functional capacity and ultimately leads to Total Knee Arthroplasty (TKA) in many of these patients. Exercise regimens prior to surgery may potentially enhance pre and post TKA functional performance. However, assessment of such performance should involve biomechanical factors that characterize the mechanisms with which tasks are performed, and not just the quantity of task performed. The present overall study investigated walking biomechanics of end stage knee OA and TKA patients. Throughout the three sub-studies that comprised the overall investigation, particular emphasis was placed on heelstrike and the loading response phase of gait, in addition to functional ability parameters. The first sub-study investigated gait biomechanics and fatigue during a 6 minute walk for patients with end stage knee OA. Results demonstrated that even if patients were able to maintain their gait velocity throughout the walk, subtle but statistically significant differences at the ankle were present after the 6 minute walk. Knee OA patients may be experiencing higher loading conditions at the knee after 6 min. In order to adapt to fatigue, knee OA patients appear to adopt ankle strategies alleviating the load from a painful knee, rather than knee strategies, causing greater instability and reduced performances. A single walking trial for gait analysis may be insufficient to assess gait compensations due to fatigue in daily activities. In light of the initial results on end stage knee OA walking biomechanics, the second sub-study included investigation of the effects of a 4 to 6 weeks exercise program on TKA outcomes. Results demonstrated that exercise therapy was effective at improving function and reducing pain to a certain extent pre-surgery. However, assessment of the walking biomechanics raised the question of whether improving physical ability improved knee OA condition or caused further knee joint degeneration and possibly the onset of OA in the opposite leg. Control patients exhibited a more careful gait pattern with lower speed and gait parameters reflecting potentially lower impact at heelstrike which may be more beneficial for knee OA conditions. The exercisers\u27 walking characteristics showed evidence of an overstriding gait pattern with potentially reduced shock absorption mechanisms that can lead to lower leg injuries. The third sub-study investigated walking biomechanics of prehab and non prehab subjects one month after surgery and results suggested that the effects of the pre-surgery exercise program did not remain post-surgery. Even if patients in the exercise group had increased physical ability performances and experienced less pain just prior to surgery compared to the control group, one month after surgery there was no difference between the groups. The lack of a significant effect of the exercise program on gait changes post surgery may indicate that the exercise regimen prior to surgery requires an additional component such as gait retraining. Adding a gait retraining component to the prehab protocol may improve the rate of recovery and help patients to maintain the prehab benefits even post TKA surgery

Influence of Patient Satisfaction of Total Knee Replacement Patients on Stair Negotiation and Walking Biomechanics, Strength, and Balance

Total knee replacement (TKR) patients have shown alterations in lower extremity biomechanics during level ground walking and stair negotiation, strength levels, and balance abilities, however, it is unknown how dissatisfied TKR patients compare to satisfied TKR patients in these activities. Study One examined the lower extremity biomechanics of dissatisfied and satisfied TKR patients during level ground walking. Study Two investigated knee biomechanics during stair ascent and descent activities. Study Three compared isokinetic strength, balance abilities, deep knee flexion abilities, and functional abilities of the dissatisfied patients to the satisfied patients. Study Four performed a logistic regression as a means of examining significant variables in models designed to predict patient satisfaction. Study One found reduced 1st and 2nd peak VGRF, knee flexion ROM, and peak loadingresponse knee extension and abduction moments in the dissatisfied patients compared to healthy controls. First and 2nd peak VGRFs and flexion ROM were reduced in the replaced limb of the dissatisfied patients compared to their non-replaced limb. Study Two showed reduced 2nd peak VGRF and loading-response knee extension moments in the replaced limb of the dissatisfied group compared to their non-replaced limb and to satisfied and healthy groups during stair ascent. 1st peak VGRF and both loading-response and push-off abduction moments showed reduced values in replaced limbs compared to non-replaced limbs for all groups. During stair descent, the dissatisfied group showed reduced loading-response and push-off knee extension moments in their replaced limb compared to their non-replaced limb and the healthy group. The loading-response knee extension and abduction moments were also reduced in the dissatisfied group compared to the satisfied group. Study Three showed reduced peak extension (180°/s) and flexion (60°/s) torque in dissatisfied patients compared to satisfied patients. No balance differences were evident, although an increased percentage of dissatisfied patients were unable to complete the unilateral balance tests. Study Four produced models via the logistic regression analysis which often included peak VGRFs and knee extension moments. Future research should examine the effects of attempting to alter the physical differences between patient satisfaction groups and whether it improves patient satisfaction rates

2023 IJSPT Orthopedic Summit Research Abstracts

The International Journal of Sports Physical Therapy is pleased to publish abstracts from the thirteenth Orthopaedic Summit (OSET) taking place in Boston, September 19-23, 2023. The IJSPT hosted the third annual research forum and reception at OSET, sponsored by ATI Physical Therapy and Hyperice. The abstracts presented in the following pages were selected by the OSET Research Committee and editorial staff of the International Journal of Sports Physical Therapy. After careful review, a total of 20 research abstracts were accepted and presented at OSET 2023. Awards for outstanding abstracts were presented on September 22. The 2023 abstracts include contemporary orthopaedic and rehabilitation topics across various research designs. Each abstract presents only a brief summary of a research project / presentation and does not permit full assessment of the scientific rigor with which the work was conducted. While the abstracts offer only preliminary results that may require further refinement and future validation, they do serve an important role in sharing new research ideas and rehabilitation advancements. This sharing of ideas helps to encourage dialogue among researchers, clinicians, and educators that will ultimately contribute to the orthopaedic and rehabilitation body of knowledge. We strongly encourage authors to continue pursuing the publication of their research as a full manuscript. Thank you to all submitting abstracts for consideration. We look forward to another outstanding season of submissions for OSET in 2024. _Phil Page PhD, PT, ATC Chuck Thigpen PhD, PT, ATC_ OSET Research Committee Co-Chair

Personalized Hip and Knee Joint Replacement

This open access book describes and illustrates the surgical techniques, implants, and technologies used for the purpose of personalized implantation of hip and knee components. This new and flourishing treatment philosophy offers important benefits over conventional systematic techniques, including component positioning appropriate to individual anatomy, improved surgical reproducibility and prosthetic performance, and a reduction in complications. The techniques described in the book aim to reproduce patients’ native anatomy and physiological joint laxity, thereby improving the prosthetic hip/knee kinematics and functional outcomes in the quest of the forgotten joint. They include kinematically aligned total knee/total hip arthroplasty, partial knee replacement, and hip resurfacing. The relevance of available and emerging technological tools for these personalized approaches is also explained, with coverage of, for example, robotics, computer-assisted surgery, and augmented reality. Contributions from surgeons who are considered world leaders in diverse fields of this novel surgical philosophy make this open access book will invaluable to a wide readership, from trainees at all levels to consultants practicing lower limb surger

The biomechanical effect of different types of footwear on medial compartment knee loading during stair ascent and descent

Introduction: Biomechanical treatments for knee OA, especially the specially designed footwear and LWIs, are commonly investigated and used during level walking. The specially designed footwear and LWIs have been suggested to potentially prevent, delay or even halt knee OA progression by reducing knee loading during level walking. However, stair walking is more challenging for individuals with knee OA because the medial knee loading is greater than that in level walking, which is usually reflected as the first complaint for early to moderate knee OA patients during stair walking. The investigation of biomechanical load-reduction footwear on medial knee loading during stair walking is limited and there is no consensus on what kind of design parameters would definitely achieve the expected biomechanical effect. The purpose of this work was to investigate the biomechanical effect of the chosen footwear during stair walking. Method: 3D motion analysis was collected on healthy individuals who were randomised to five different footwear conditions (standard shoe, LWI inserted into standard shoe, mobility shoe, Melbourne OA shoe and variable stiffness shoe) during stair ascent and descent. Each participant performed five valid trials of stair ascent and descent for both limbs under each condition. Repeated measures ANOVA and Friedman’s ANOVA were used for statistical analysis. Result: Sixteen participants (eight male and eight female) took part in the study. The knee loading variables of the first and second peaks of the EKAM, and KAAI were significantly reduced when using LWI, Melbourne OA shoe and mobility shoe in comparison with the standard shoe during both stair ascent and descent. However, such reductions were not identified in the variable stiffness shoe. Conclusion: The specially designed footwear (LWI, Melbourne OA shoe and mobility shoe) demonstrated to reduce both peak medial knee loading and cumulative knee loading during stair ascent and descent compared with wearing standard shoe. However, the similarly designed variable stiffness shoe did not demonstrate the same biomechanical effects. These results support that the use of specially designed shoes might be useful as a biomechanical treatment in individuals with medial knee OA during stair ascent and descent

Body sensor networks: smart monitoring solutions after reconstructive surgery

Advances in reconstructive surgery are providing treatment options in the face of major trauma and cancer. Body Sensor Networks (BSN) have the potential to offer smart solutions to a range of clinical challenges. The aim of this thesis was to review the current state of the art devices, then develop and apply bespoke technologies developed by the Hamlyn Centre BSN engineering team supported by the EPSRC ESPRIT programme to deliver post-operative monitoring options for patients undergoing reconstructive surgery. A wireless optical sensor was developed to provide a continuous monitoring solution for free tissue transplants (free flaps). By recording backscattered light from 2 different source wavelengths, we were able to estimate the oxygenation of the superficial microvasculature. In a custom-made upper limb pressure cuff model, forearm deoxygenation measured by our sensor and gold standard equipment showed strong correlations, with incremental reductions in response to increased cuff inflation durations. Such a device might allow early detection of flap failure, optimising the likelihood of flap salvage. An ear-worn activity recognition sensor was utilised to provide a platform capable of facilitating objective assessment of functional mobility. This work evolved from an initial feasibility study in a knee replacement cohort, to a larger clinical trial designed to establish a novel mobility score in patients recovering from open tibial fractures (OTF). The Hamlyn Mobility Score (HMS) assesses mobility over 3 activities of daily living: walking, stair climbing, and standing from a chair. Sensor-derived parameters including variation in both temporal and force aspects of gait were validated to measure differences in performance in line with fracture severity, which also matched questionnaire-based assessments. Monitoring the OTF cohort over 12 months with the HMS allowed functional recovery to be profiled in great detail. Further, a novel finding of continued improvements in walking quality after a plateau in walking quantity was demonstrated objectively. The methods described in this thesis provide an opportunity to revamp the recovery paradigm through continuous, objective patient monitoring along with self-directed, personalised rehabilitation strategies, which has the potential to improve both the quality and cost-effectiveness of reconstructive surgery services.Open Acces

Do East Asians Achieve Greater Knee Flexion than Caucasian North Americans, and are East Asian Kneeling and Squatting Styles Kinetically Different from North American Norms?

High flexion postures (specifically, kneeling and squatting) are used with greater regularity in East Asian (Chinese, Japanese, Korean, and Vietnamese) cultures for many activities of daily living (ADL). Furthermore, the favored style of kneeling and squatting is different between ethnicities: Caucasians typically flex their forefoot while kneeling and squatting, whereas East Asians tend to keep the top or bottom of the foot flat to the ground. Most, but not all, research suggests that East Asians are able to achieve a greater knee flexion angle during high flexion postures, but it is unknown if any differences between ethnicity extends to kinetic outcomes. A direct comparison between ethnicities with respect to kinetics has not been made. Where a difference in maximal attainable flexion angle exists, it is unclear whether the cause is cultural or innate. Therefore, this thesis project aimed to answer three related questions: 1) Do East Asian populations achieve a greater flexion angle than North American Caucasians; 2) If there is in fact a difference, is it a result of cultural upbringing or innate ability?; and, 3) Do different styles of kneeling and squatting alter the moments of force at the knee? To accomplish these aims, 43 participants were recruited from the University of Waterloo and fit into one of three groups: Caucasian, born and raised in North America (20 participants); East Asian, born and raised in North America (18 participants); or, East Asian, born in East Asia, living in North America for less than two years (five participants) (however, the East Asian born in East Asia group was excluded from statistical processing since the group size was considerably smaller). Kinetic, kinematic, neuromuscular, and passive range of motion data were collected and compared between different ethnicity groups. East Asians did not achieve a greater mean knee flexion angle during kneeling compared to Caucasians (Canadian born East Asians=152.01° (±4.85°); Caucasians=153.07° (±7.46°), p=0.2859), but a greater mean flexion angle was found during squatting (Canadian born East Asians =147.96° (±6.62°); Caucasians = 141.69° (±17.48°), p=0.0014). Between Caucasians and Canadian born East Asians, there was also no difference in peak knee flexion angle during passive range of motion testing (Canadian born East Asians = 152.05° (±8.16°); Caucasians = 149.54° (±7.75°)), which indicates that there is no difference in ability to achieve greater high flexion between groups. Finally, it was found that different styles of squatting altered the kinetics at the knee, but different styles of kneeling were not significantly different. Flat foot squatting, a posture more commonly seen in East Asian cultures, had significantly (p<0.05) lower flexion and adduction moments at the knee than heels raised squatting (which is more commonly used by Caucasian North Americans) during descent, ascent, and static squatting. The mean static flexion moment (which is similar in magnitude to the peak flexion moment during descent and ascent) for flat foot squatting was 4.37 (±1.47) %BW*Ht, and for heels raised squatting was 5.99 (±1.84) %BW*Ht. The mean static frontal plane moment for flat foot squatting was -0.45 (±1.33) and for heels raised squatting was 0.59 (±1.02). (Negative values indicate an external abduction moment and positive values indicate an external adduction moment.) When performing high flexion postures, reduced knee moments are desirable since higher moments are associated with greater joint loading and injury risk