I was honored to recently present my doctoral research on total knee replacement (TKR) rehabilitation at the American Physical Therapy Association Combined Sections Meeting in Chicago. The outpatient orthopedic service at HHH provides services for adults with a variety of orthopedic problems, with diagnosis ranging from arthritis to sport medicine and from disc herniation to joint replacement.
Knee damage or advanced arthritis can lead to debilitating knee pain. A knee joint replacement removes the arthritis and replaces the bone with a prosthesis. Six hundred thousand total knee replacements are performed annually according to the American Association of Orthopedic Surgeons. When the arthritis is removed, the pain is alleviated. However, functional outcomes vary after TKR. Physical therapy programs also vary with no single best rehabilitation protocol identified. This research conducted at Helen Hayes Hospital tested two exercise protocols in a search for best physical therapy practice following TKR.
I studied the effects of two types of exercise routines on outcomes following TKR. Intensity of exercise was similar but velocity was different. Patients began the study two weeks after TKR when they were randomly assigned to do standard low velocity exercise or to exercise at a power training speed of less than one second for a muscle contraction. The training program lasted six weeks.
Both groups of patients improved significantly in walking speed, distance walked, and perceived health. Only the high velocity exercise group reported a decrease in pain during the six weeks of the study. The outcomes of this study indicate that when intensity is progressed as regular intervals, then speed of muscle contraction can vary during exercise with achievement of comparable outcomes. Results of this study contributed to the research evidence available to physical therapists that they can then use to design exercise programs for patients who have had TKR.
Marie A. Kardys Kelly PT DHS OCS FAAOMPT
Coordinator Outpatient Orthopedic Physical Therapy