Effects of Pre-Operative Exercise Instruction in Improving Post-Operative Functional Outcomes and Reducing
Outpatient Physical Therapy Visits on Patients Receiving Total Knee Arthroplasty
Megan Pline, PT, DPT, Edwin James, BS, PT, Claire Kalpakjian, PhD
University of Michigan, Ann Arbor, MI
BACKGROUND & OBJECTIVE HOME EXERCISE PROGRAM RESULTS
As the prevalence of total knee arthroplasties increases, ways to improve outcomes and The treatment group was instructed in a detailed home exercise program that they were to Figure 3. Mean WOMAC scores across
return patients to their previous functional status quicker are constantly being developed. perform at least two times per day until day of surgery. assessment periods. Both groups
The purpose of this research was to test the effectiveness of a new structured pre- experienced similar drops in WOMAC scores
operative home exercise program with respect to pain rating and functional outcomes as For each exercise subjects were instructed in the frequency, intensity, and duration. across the study period with the treatment
measured by Knee Society Clinical Rating scores and WOMAC scores in patients group generally scoring lower than the control
receiving total knee arthroplasty. The home exercise program was provided to the subjects in a paper format and through an
instructional DVD that they could re-watch as needed at home.
Weekly phone calls were made to the treatment group to see how the home exercise
Eighteen adults (7 males, 11 females) aged 52-87 years old, scheduled for total knee program was going and to make sure the subjects were preforming the exercises.
arthroplasties (TKA) with the Department of Orthopedic Surgery Adult Lower Extremity
Reconstruction Clinic at the University of Michigan, were involved in this study. Exclusion Subjects were also given a tracking log for performance of exercises and instructed to
criteria included: diabetes, cardiovascular disease, morbid obesity (BMI>40), current check off on a chart each time they completed the exercises.
tobacco use, TKA secondary to avascular necrosis or traumatic injury, post-operative Figure 4. Mean pain rating across
assessment periods. Both groups
complications including a prolonged hospital stay (>5 days) , and complications due to The home exercise program (HEP) included the following exercises: heel slides, straight experienced similar drops in pain rating
surgery (deep vein thrombosis/es, cardiac arrhythmia, infection). leg raises, short arc quads, hook-lying resisted hip abduction, clams, long arc quads, across the study period with the treatment
seated hamstring stretch, standing resisted hip abduction, and standing heel raises. group generally rating their pain lower than
the control group.
Enrollment Assessed for eligibility (n=252)
Intervention Group Control Group
(N = 9) (N = 6)
Scheduled with the wrong physician
Scheduled less than 1 month in Age (mean, SD) 71, 7.5 71, 6.4
Not living close enough to the clinic
Gender (N, %)
Male 3, 33% 3, 50%
Female 6, 67% 3, 50%
Allocation BMI (N, %)
Allocated to intervention (n=10) Allocated to control (n=8) 15 through 20 1, 11% 0, 0%
Received allocated intervention (n=10) Received standard of care (n=8) 21 through 25 0, 0% 1, 17%
26 through 30 1, 11% 3, 50%
31 through 35 1, 11% 2, 33%
Follow-Up 36 through 40 6, 67% 0, 0%
Figure 5. Mean Knee Society Rating across
assessment periods. Across the study
Lost to follow-up (had outpatient physical Lost to follow-up (had outpatient physical
therapy at a different location) (n=1) therapy at a different location) (n=2) Surgical Knee (N, %) period, Knee Society Ratings were highly
4, 44% 2, 33%
5, 56% 4, 67% variable though the parallel lines by group
Analysed (n=9) Analysed (n=6)
indicate that the variability was similar
between groups. It is interesting to note that
Figure 1. CONSORT Table Figure 2. Sample Characteristics for both groups the lowest Knee Society
Rating was found immediately after surgery.
METHODS & MATERIALS
This study was a randomized controlled clinical trial using parallel group randomization to
allocate participants to receive the new pre-operative home program or standard of care.
The standard of care for rehabilitation of a TKA is to have only post-operative physical
therapy and to not have any pre-operative therapy. Participants underwent a baseline
assessment one month prior to surgery completing the following: DISCUSSION & CONCLUSIONS
There was no statistical difference in the outcomes of total knee arthroplasty subjects that
Knee range of motion (flexion and extension) receive a pre-operative exercise program compared to subjects that do not. This may in
Single leg stance time part be due to the small sample size and it may also be due to the length of the
Gait velocity intervention. One month of a HEP may not have been long enough to produce differences
Berg balance scores in strength and range of motion between the groups. It would be worthwhile to look at a
Western Ontario and McMaster (WOMAC) Universities Arthritis Index longer pre-operative program.
Knee Society Clinical Rating scores
Pain rating using a visual analog scale (0-10) There was a statistically significant change within the treatment group for the WOMAC
score between the second pre-surgery measurement and the one month follow-up post-
Follow up assessments of both groups were performed one week prior to surgery, at the therapy. This was not true for the control group. The WOMAC score is a subjective
start of outpatient physical therapy, and weekly until discharge criteria was met (from measurement given by the patient. It may be that the treatment group had greater
outpatient physical therapy). confidence in their ability to perform activities of daily living after spending time pre-
operatively on the home exercise program.
Discharge criteria from outpatient physical therapy included achieving knee flexion of at
least 110 degrees, knee extension of at least 0 degrees, There were multiple limitations with this study including a small sample size due to
AND difficulties of recruiting. There was a large percentage of TKA subjects scheduled less than
one month prior to surgery which made them ineligible for the study as well as a large
meeting at least two of the following criteria: percentage of patients scheduled with the surgeon not included in the study. One other
Single leg stance time of 30 seconds or greater limitation was the fact that the researchers were not blinded to the groups.
Berg Balance Test score of 45 or greater
Gait velocity of at least 0.8 meters/second The outcomes of this study also indicate the need for additional research into providing a
longer lead time for conducting pre-op exercises and the incorporation of additional direct
The final assessment was one month post-discharge from outpatient physical therapy. Physical Therapy interventions pre-operatively.
All physical therapy was performed at the University of Michigan MedRehab physical ACKNOWLEDGMENTS
therapy clinic in Canton, MI. This study was funded by a grant from the University of Michigan Practice-Oriented
Research Training (PORT) Program and the Department of Physical Medicine and
During physical therapy sessions all participants received the same type of treatment for Rehabilitation. The PORT Program is part of the Michigan Institute for Clinical and Health
rehabilitation of a total knee arthroplasty. A combination of manual therapy as well as Research at the University of Michigan and supported by a grant from the National
therapeutic exercise and activity was done. Institutes of Health Clinical and Translations Sciences Award (#UL1RR024986).