Optimizing functional and biomechanical outcomes following total joint arthroplasty
Date
2015
Authors
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Publisher
University of Delaware
Abstract
Total joint arthroplasties are common and effective orthopeadic surgery. Patients often experience significant reduction of pain and improvement of perception of function after the surgery. However, patients continue to exhibit biomechanical abnormalities, functional limitations, decreased performance, and reduced activity level compared to older adults without joint pathology.
The overall purpose of this dissertation was to identify optimal rehabilitation strategies to improve outcomes of patients following total joint arthroplasty surgery. A systematic review of randomized controlled trials was performed to understand optimal rehabilitation treatments for patients after total knee arthroplasty (TKA). Four categories of postoperative treatment strategies were discussed: 1) strengthening exercises; 2) aquatic therapy; 3) balance training; and 4) clinical environment.
A secondary analysis of data from a randomized controlled trial was performed to understand the effectiveness of a progressive strengthening rehabilitation protocol to restore normal physical function after TKA. Data from a control group of older adults without knee pathology were used to build normality intervals for several outcome measures. The proportion of patients after TKA that met a normality cut-off was then compared between a group of patients who underwent progressive strengthening and standard of care rehabilitation. A longitudinal study was conducted to understand the recovery of patients in the first 12 months after total hip arthroplasty (THA). Recovery was evaluated using a comprehensive set of outcomes, including self-reported measures of function, impairment based, performance based, and biomechanical measures. Predictors of performance at 12 months were also evaluated to understand impairments associated with optimal recovery.
The feasibility and preliminary effectiveness of a behavioral and exercise intervention for patients 3 to 9 months following THA was then evaluated. The intervention included meetings with a health coach to discuss healthy lifestyle habit, barriers to exercise, and strategies to stay engaged in physical activity. Additionally, patients took part in 18 supervised exercise sessions over the course of six weeks that included two aerobic and one strengthening component. Feasibility was evaluated in terms of session attendance and occurrence of adverse effects (i.e., joint pain, swelling, and tenderness) occurrence. Preliminary effectiveness was evaluated using a comprehensive set of outcomes, including self-reported measures of function and physical activities, impairment based, performance based, and biomechanical measures.
The information obtained in this dissertation further support the importance of progressive strengthening and functional training following TKA. These exercises should be progressed as subjects meet clinical milestones to maintain appropriate intensity. A greater proportion of patients enrolled in a progressive strengthening rehabilitation protocol reached a level of physical function similar to healthy older adults. Therefore, this type of protocol may be more effective compared to standard rehabilitation protocols.
The recovery of patients after THA is not optimal in terms of functional and biomechanical outcomes. Important weakness of hip abductor strength persisted 12 month after surgery. While biomechanical abnormality in the sagittal plane appear to resolve after surgery, excessive trunk lean and pelvis drop angle persist up to 12 months following the surgery. An aerobic and strengthening intervention is feasible and well tolerated in patients at least 3 months following THA. The intervention is effective in improving physical activity and may promote return to higher level of recreational and sport activities. Although hip abductor strength increased at the end of the intervention, weakness in the surgical side persisted compared to the non-surgical side. Biomechanical changes were more variable between subjects. Trend toward greater hip flexion angle and internal flexion moment were seen, and may suggest better dynamic hip joint function.