Strength, Mobility, Function, and Balance after Total Knee Arthroplasty Michelle Grace, SPT; Mackenzie Janner, SPT; Kristin McReynolds, SPT; Lindsay Oliver, SPT Faculty Mentor: Mohammed Kohia PT, Ph.D., MS
Purpose/Hypothesis: Controversy exist in the literature regarding the successful outcomes following Total Knee Arthroplasty (TKA). The purpose of this study was to determine functional outcomes at 1-3 months post TKA. It was hypothesized that patients operated knee will have decreased range of motion (ROM) and strength compared to the non operated knee, and patient’s will display a moderate level of functional ability with Sit to Stand (STS) and Timed Up and Go (TUG) tasks.
Subjects: A total of 10 subjects who underwent a primary, unilateral TKA (age 62.5±9.40 years, weight 172±22.53 lbs, height 66.4±5.37 inches) participated in this study.
Methods and Materials: Quadriceps and Hamstrings strength were measured using manual muscle testing (MMT). Knee flexion and extension ROM were measured using universal goniometer. Strength and ROM measurements were compared between involved and un-involved sides. Subjects’ balance and reported functional performance were tested using TUG, STS tests, and the WOMAC questionnaire. A Paired t-test was used to compare ROM and strength between operated and non-operated knees. The WOMAC, TUG, and STS tests were reported as frequency distributions.
Results: A significant difference (p=0.03) was observed between involved and uninvolved quadriceps and hamstrings strength, with the involved knee being weaker. ROM measurements showed a significant difference (p=0.004) for flexion and no significant difference for extension (p=0.07). On average, flexion was 16.4 degrees less on the involved side. Self-reported WOMAC questionnaire showed 40% having no to minimal pain, 30% having minimal to moderate pain, and 30% having moderate to severe pain. Half of participants reported minimal to moderate stiffness, 40% reported moderate to severe stiffness, and 10% reported severe to extreme stiffness. Functionally, 40% reported no to minimal difficulty, 40% having minimal to moderate difficulty, and 20% having moderate to severe difficulty. The TUG results showed that 54.5% had no noticeable change with or without dual task, while 36.4% experienced a change in counting or walking time. The STS showed that 81.8% came to stand normally without use of hands and 9.1% came to stand with use of hands on the first attempt.
Conclusions: Overall the results of this study showed that patients 1-3 months post-TKA have decreased strength and flexion range of motion in their operated knee compared to uninvolved knee. However in terms of functional ability and balance, they are reporting limited restriction of ability to perform daily tasks. Considering the fact that patients will likely continue to gain strength and ROM beyond two months postoperatively, it can be concluded that functional outcomes after TKA are positive, but future research in this area is warranted.