Is There an Alternative to Immediate Home Physical Therapy Following Total Knee Arthroplasty
Phase: NA
Conditions: Total Knee Arthroplasty
Sponsor: Wolfgang Fitz, M.D.

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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
Is there an Alternative to Immediate Home Physical Therapy 
Following Total Knee Arthroplasty? 
 
A randomized controlled trial comparing home physical therapy, 
telemedicine-guided exercises, and an e-stim garment 
 
Version Date: 5/28/2019 
 
I. BACKGROUND AND SIGNIFICANCE 
 
In July 2016, a meta-analysis was published that compared the effectiveness of home-based 
exercises with individualized outpatient physical therapy programs.  Though the 11 studies 
examined were high in statistical heterogeneity, with moderate quality and small sample sizes, 
the analysis found no clear difference between home-based exercises and standard PT programs 
after total knee replacement.  Outcome measures included knee range of motion (ROM) and 
various functional measures at 3, 6, and 12 months [1].  
 
Other studies have confirmed these findings.  In 2009 Coppola and Collins conducted a similar 
review of randomized controlled trials to compare PT with home exercise.  Though the trials 
were generally not applicable to an older population with frequent comorbidities, the review also 
found no clear difference between the modes of therapy [2].  Artz et al. demonstrated improved 
physical function in patients receiving PT exercises compared to any other physical therapy 
technique, though in his study there were patients who had supervised PT exercises at their 
homes [3].   
 
Other studies have examined outcomes such as knee ROM and questionnaire-based measures 
such as WOMAC, KSS and OKS, and have found a correlation between positive outcomes on 
both scores [4].  These various patient-reported measures were found to be no different between 
PT patients and alternative-method patients in two studies by Kramer et al. [5] and Ko et al. [6].  
Even hospital readmission rates (within 6 weeks of surgery) were comparable between methods 
[7]. 
 
With the recent rise in the use of telemedicine for diagnosis and treatment, telemedical 
approaches to physical therapy, such as home-based exercise programs, have grown in 
popularity.  Rather than sending patients home with a simple sheet of instructions, online rehab 
programs allow for regular updates to exercise programs as well as mechanisms for patients to 
provide real-time feedback on their progress.  Given the comparability of home-based exercise to 
traditional PT, telemedical approaches may be worth considering in the future.  For patients 
using an online program, the concomitant lowering of cost would certainly increase the overall 
value of this mode of treatment. 
 
A second alternative to traditional physical therapy is known as neuromuscular electrical 
stimulation (NMES).  This technique, colloquially called “e-stim,” is used to engage the 
quadriceps muscle, which undergoes a dramatic weakening, up to a 60% loss of strength, 
following total knee arthroplasty [13].  In e-stim, electrodes are thus positioned around the thigh; 
many NMES technologies integrate these electrodes into a brace that the patient wears.  The 

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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
electrodes then conduct electrical signals to the muscle, mimicking the nervous system’s own 
action potentials and causing the muscle cells to contract.  The level of stimulation increases with 
the intensity of the current, which can be controlled by the patient in today’s NMES devices.   
 
For patients who receive total knee replacements, combining e-stim therapy with physical 
therapy in the preoperative and early postoperative stages has been shown to reduce knee 
extensor lag, decrease length of stay, and improve short-term walking speed up to one year after 
surgery.  One study found that electrical stimulation improved the American Knee Score and the 
Oxford Knee Score for patients six weeks out of surgery.  Statistically significant changes in 
walking speed and functional recovery were both noted [14]. 
 
As mentioned above, we also know that one month after TKA, quadriceps muscle strength has 
typically dropped by about 50–60% of its preoperative levels [15].  This weakness tends to 
persist in the years following surgery, often causing loss of balance, falls, and greater difficulty 
with standing up or climbing stairs.  Literature on the topic suggests that NMES may effectively 
(though not perfectly) attenuate the loss of quad strength and improve functional performance 
following total knee replacement [16–19].  Although the learning curve has required 
supplementary education at times, such devices are less expensive than physical therapy and 
would thus be a welcome alternative to PT if its effects are indeed comparable. 
 
Overall, we propose a non-superiority treatment study that will compare our traditional standard 
of care (home visiting physical therapists) with telemedical home-based therapy and with e-stim 
technology. 
 
 
II. SPECIFIC AIMS 
 
The purpose of this study is to investigate the superiority of telemedicine-guided physical 
therapy and e-stim devices in the first three weeks after a total knee replacement, compared with 
the current standard of care of home physical therapy.  We propose equal outcome measures 
such as quadriceps strength, rage of motion, proprioception, functional tests, and general 
outcome measures at 2–3 months following total knee replacement.  
 
We propose that a decrease of cost for outpatient physical therapy by 50% without decreasing 
outcome by more than 10% would create value, but that any decrease in cost must not result in a 
decrease in outcomes. 
 
 
III. SUBJECT ENROLLMENT 
 
Subjects for this study include all patients who are aged 18 or older and electing to undergo 
unilateral total knee replacement (TKR) with Dr. Wolfgang Fitz at Brigham and Women’s 
Faulkner Hospital (BWFH) regardless of sex or other status.  
 
Inclusion criteria:  
- 
Age 18 or older 
- 
Owns a device with internet connection 

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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
- 
Can download the E-vive application for the contractile garment (has sufficiently up-to-
date phone or tablet, or has family member with such a device). 
- 
Has a rudimentary understanding of Internet technology, especially e-mail 
- 
Has a flexion of 90 o and flexion contracture of 5 o at the point of discharge 
- 
Approved by a physical therapist to participate safely in the study at the time of discharge 
 
Exclusion Criteria:   
- 
Rheumatoid arthritis  
- 
History of epilepsy 
- 
Implanted and body-worn electronic medical device, including cardiac pacemakers, 
neural stimulators, insulin pumps, etc. 
- 
Poor understanding of the use of the brace/electrical stimulation 
- 
Lesions on the skin over the thigh 
- 
Uncontrolled diabetes 
- 
Uncontrolled hypertension 
- 
Bilateral TKA or UKA planned 
- 
If female, pregnant 
- 
Cannot use non-operated leg postoperatively to propel active motion splint, caused by 
neurological or muscular diseases such as complete or incomplete paralysis or other 
causes of weakness with an inability to bend or extend knee 
- 
Loss of sensation in operated or non-operated leg 
- 
Has below- or above-knee amputations of non-operative leg 
- 
Below- knee amputation of operated side 
- 
Chronic pain syndrome with inability to walk 
- 
Taking chronic narcotics and/or is taking more than 10mg codeine per day, or any 
Hydrocodone, or more than 200 mg of tramadol, or any other narcotics prescribed for 
moderate to severe pain 
- 
Involved in pain clinics for chronic pain, or pain that is not related to the knee 
- 
Has been diagnosed with knee disorder other than osteoarthritis, post-traumatic 
osteoarthritis, gout, pseudo gout, or any inability to walk due to disorders unrelated to the 
knee (e.g., hip disorders, spinal stenosis, paralysis, hemi-paralysis) 
 
 
V. STUDY PRODECURES 
 
Patients who are undergoing total knee replacement (TKR) with Dr. Wolfgang Fitz at Brigham 
and Women’s Faulkner Hospital and meet all eligibility criteria will be informed about the study 
and asked if they would like to participate.  The research assistant (RA) will screen upcoming 
surgeries and mail a letter describing the study to all qualifying patients to inform them of the 
study.  If the patient has not contacted the study team within one week after this letter is mailed, 
the RA will call the patient by phone and ask whether the patient agrees to participate. Those 
who show interest will be offered the opportunity to discuss with both the RA and Principal 
Investigator (PI). Upon agreement, the patient’s consent will be obtained and they will be 
randomly assigned to a treatment group using a computer-generated randomization. 
 

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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
A standardized mean difference of 0.90 has been reported in the previous published studies for 
quadriceps muscle strength between control and NMES intervention groups.  This study will 
require 26 patients per group using this standardized mean difference, along with 80% power and 
the level of significance (p-value) set to 0.05.  Adding in a 10% expected dropout rate, planned 
enrollment will be 29 patients per group for a total enrollment of 87 patients. 
 
Approximately 2-3 months before surgery, patients will sign informed consent and will be 
randomly assigned to one of 3 treatment groups, to be described in detail below.  Patients in all 
groups will receive a standardized telemedical “Pre-Hab” program (iGetBetter, Southborough, 
MA) to be followed in anticipation of surgery.  This program includes both strengthening 
exercises and proprioception exercises.  Prior to enrolling in the Pre-Hab program, all patients 
will undergo our standardized functional testing, including proprioceptive evaluation.  The RA 
will also give each patient a live tutorial on how to use iGetBetter. 
 
During their preoperative appointments, all patients will undergo preoperative testing to assess 
joint function and leg strength.  Tests will measure sit-to-stand capabilities, quadriceps strength, 
distance walked in 2 minutes, walking speed, proprioception (balance), and range of motion. 
 
Before surgery, Patients in Group 1 (the first treatment group) will receive no treatment except 
for iGetBetter; this is the current preoperative standard of care.  After surgery, Group 1 patients 
will be given a Post-Op program from iGetBetter to use for 2–3 months.  For the first 3 weeks, 
patients will only use iGetBetter.  After those 3 weeks have elapsed, the patient will receive 
outpatient physical therapy in addition to iGetBetter, approximately twice per week for the next 
6–8 weeks as all other groups. 
 
Before surgery, Patients in Group 2 (the second treatment group) will receive iGetBetter like the 
other groups.  They will also receive CyMedica’s “E-vive” conductive garment and asked to 
download the corresponding smartphone application.  They will be instructed to wear the e-stim 
garment two times each day, for 20 minute intervals each, for the 3 weeks immediately before 
surgery, and to change the electrodes weekly. 
 
Stimulation from the garment will have the following parameters: frequency of 50 Hz; pulse 
duration of 5 ms; time on: 12.8 seconds; and time off: 10 seconds.  The total contraction time in 
a 20-minute treatment will be 11 minutes.  The waveform will be pulsed and asymmetrical.    
 
Patients will be instructed on the proper use of the brace, including not to apply the two therapies 
consecutively to provide sufficient recovery time between sessions (recommended therapy is one 
session in the morning and one session in the afternoon/evening), and not to engage the NMES 
beyond what he or she can tolerate. 
 
After surgery, Group 2 patients will immediately continue using the E-vive e-stim device, 
starting on the DOS.  They will be taught how to use the device safely over their surgically 
repaired leg.  For the first 3 weeks, they will only use the E-vive device, 2 times per day.  After 
those 3 weeks have elapsed, the patient will receive outpatient physical therapy in addition to the 
E-vive home-based e-stim therapy, approximately twice per week for the next 6–8 weeks. 
 

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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
Before surgery, Patients in Group 3 (the control group) will receive no treatment except for 
iGetBetter; this is the preoperative standard of care.  After surgery, Group 3 patients will receive 
the postoperative standard of care for total knee replacements at BWH.  For the first 3 weeks, 
patients will receive home physical therapy.  After those 3 weeks have elapsed, the patient will 
receive outpatient physical therapy approximately twice per week for the next 6–8 weeks.   
 
Patients in all groups will attend two routine follow-up visits.  The first will occur one week after 
surgery; there patients will have their dressing changed and receive narcotic prescriptions.  At 
the second follow-up, which will occur 2–3 months after surgery, patients will receive the 
functional testing described above.  We will also calculate total cost of the three different 
treatment modalities. 
 
Additional routine data — including postoperative complications for infection, readmission rates, 
and routinely collected functional outcome measures — will be recorded at this 2- to 3-month 
visit.  For all groups, the standard of care is to administer an opioid consumption diary in which 
patients submit VAS scores for pain, nausea, and satisfaction. The PI will review this diary with 
the patient during the first postoperative visit, and then again at the second. We will measure 
patients’ pain, both in terms of VAS scores and in terms of total pain medications consumed. 
Each of these measures will be used for analysis at the completion of the study.  
 
 
VI. BIOSTATISTICAL ANALYSIS 
 
We will be comparing the three separate groups in the trial to see whether there exists a 
statistically significant difference between them.  Variables in which we are interested are all 
detailed in the previous section.  When comparing the three branches, all analyses will be run at 
a type I error rate of 5%. 
 
VII. RISKS AND DISCOMFORTS 
It is possible that the iGetBetter group could have worse outcomes than the other two groups if a 
patient does not log into the program, or does too many (or too few) of the exercises prescribed. 
However, our current experience is a high compliance rate with iGetBetter exercises and good 
hip and knee strength and standing balance 2 months after total knee replacement. Risks 
associated with a web-based rehabilitation program will be minimized by closely monitoring all 
information recorded by the patient.  If patients are recording high pain scores or not recording 
exercises, the PI will be notified and the RA will contact those patients. 
 
It is also possible that the E-vive group could have worse outcomes than the other two groups if 
the patients use the device too little or too much, or if they do not supplement the stimulation of 
the quad with stretches from outpatient physical therapy designed to improve range of motion. 
The device is linked through a smartphone to monitor compliance and range of motion. On rare 
occasions, E-vive therapy can result in skin reactions such as rash, inflammation, irritation, or 
electrode burns. 
 

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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
It is possible that the three groups may demonstrate different levels of postoperative outcomes 
and patient satisfaction — though we do not have a clear hypothesis as to which groups will 
yield the highest and lowest scores. 
 
All risks and strategies for mitigation will be clearly explained during the consent process.  
 
VIII. POTENTIAL BENEFITS 
 
While no benefit to participation is ensured, it is possible that the patients in Group 1 may benefit 
from improvement of hip and knee strength and improved standing balance, and our preliminary 
unpublished results prove this. Patients are also tethered to Dr. Fitz through their pain, 
satisfaction, and sleep reports. Patients in Group 2 might demonstrate similar increased muscle 
strength and similar range of motion compared to the other groups. Due to the established nature 
of PT, our current standard of care (Group 3) will show similar or better outcomes compared to 
Group 1 and Group 2 measured by our outcomes variables. 
 
Results of this study may also help to improve treatment options for patients recovering from 
TKRs. 
 
IX. MONITORING AND QUALITY ASSURANCE 
 
Data which could indicate a potential complication, whether related to the study or not — such 
as heightened risk of adverse outcomes, insufficient range of motion on the operated joint, or 
inability to use the web-based program — will be addressed by the PI immediately and reported 
in accordance with PHRC guidelines. The PI will determine if the study should be altered in any 
way or stopped for safety reasons.   
 
Reasons for stoppage include a rate of adverse events greater than 10% in either group.  These 
checks will help to ensure validity and patient safety.  Unanticipated problems and adverse 
events will be reported to the PHRC in accordance with PHRC guidelines.   

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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
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Detailed Protocol: Postoperative Web-based Rehabilitation Program for Patients Undergoing a Unilateral Total Knee Replacement  
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