ABSTRACT Background: Pressure Modulated Knee Rehabilitation Machine (PMKR), the X10 Purpose: Methods:

Transcription

1

2 ABSTRACT Background: Kevin, our 58 year- old patient, had total knee arthroplasty on both knees. The first was a left knee partial knee replacement, August 11, Kevin had a right total knee arthroplasty on May 30, 2014 following an industrial accident at his job site, the Port Authority of New Jersey. His employer allowed him one year to recovery and return to work. Subsequent to his surgery, in July of 2014 his physical therapist ripped his right quadriceps tendon while manipulating his leg causing Kevin to temporarily cease therapy - which resumed in October In February of 2015, Kevin had achieved 97 degrees range of motion, was not making significant gains and again had to cease therapy because of emergency stomach surgery. By mid- March 2015 he was once again ready to restart his physical therapy. However, with only 12 weeks remaining before he had to return to work his physician was ready to sign permanent disability papers, because of Kevin s lack of progress. Kevin s right leg had significant atrophy and he was unable to walk without a cane or walker. At this point, Kevin became aware of the newly patented Pressure Modulated Knee Rehabilitation Machine (PMKR), the X10 and contacted its manufacturer, Halley Orthopedics. Kevin began using the X10 on March 15, 2015, having only until May 30 th to fully recover and return to work or lose his job. Ten weeks later Kevin reported to work with a full range of motion and able to walk (all day in construction shoes) the necessary 10,000 steps a day to do his job. Purpose: Here we describe how the PMKR X10 machine can be used to rapidly facilitate patient recovery of strength and motion following a total knee replacement, even nine to ten months post- surgery with no manual physical therapy. We also illustrate the use of a FitBit to assess daily patient progress. Methods: Kevin was given an initial assessment consisting of: 1) measuring his range of motion, using the X10, 2) the Tinetti Performance Mobility Oriented Assessment (Tinetti et al., 1986), 3) the TUG test (Mathias et al. 1986, Podsiadlo and Richardson 1991), and 4 the WOMAC test (Quintana, et al., 2006 and Riddle et al., 2012) to assess his functional status). Kevin used the X10 three times a day for thirty minutes each time. The X10 s onboard computer continually assessed and recorded his performance stroke by stroke, enabling Kevin to see his progress and to transmit data to his coach who monitored his progress.

3 Results: In seven weeks of X10 use Kevin s right leg ROM increased from 112 to 129 (he ultimately reached 130 ). His left leg ROM increased by 14. The Tinetti, TUG and WOMAC were given on March 15 th and May 15 th. The Tinetti went from 8/16 to 16/16, The TUG went from 25 seconds to 8 seconds and the WOMAC went from 80/96 to 46/96. Kevin s right quadriceps strength at 40 (for example) increased four- fold, and his right hamstring strength increased seven fold. The FitBit data showed that on March 15 th Kevin was doing less than 100 steps a day and by May 15 he was doing over 11,000 steps a day. His sedentary time decreased by more than minutes a day and his activity increased by a similar amount. By May 15, Kevin was burning more than 1000 additional calories a day, a 50% increase. Kevin s pain had entirely ceased in both legs by April 29 th and remained at 0 thereafter. Conclusion: The use of the X10 enabled Kevin to recover his full range of motion in less than 10 weeks and become fully functional. He achieved this by using X10 two to three times a day for 30 minutes for range of motion, and every other day on the strengthening modules on the X10. Kevin used the X10 in his own home without direct supervision from a physical therapist. Moreover, the X10 s onboard computer continually assessed his performance stroke by stroke, enabling Kevin to see his progress and to record it and transmit it to his coach so that Kevin could be discharged from treatment based upon his performance and not the time spent in therapy. These data support the conclusion that X10 can radically reduce the time needed for recovery from a TKA and allow patient discharged, not based upon the number of visits, but rather objective outcome measures. Accordingly, the X10 can usher in a new era both in cost savings and research.

4 INTRODUCTION A few hours post- TKA surgery, inflammatory mediators are released by platelets and dead or injured cells, causing nearby blood vessels to dilate and leak plasma causing subsequent periarticular tissue swelling (O Driscoll et al. 2000). This swelling physically diminishes the ability of the knee to flex and it reduces the neuromuscular compliance of the major leg muscles, making bending the knee more difficult and more painful to move (O Driscoll et al. 2000). The fluid composition also promotes the formation of scar tissue which impedes recovery even further (O Driscoll et al. 1983). These conditions can persist for months or years resulting in diminished quality of life and leading to depression (Mizner et al. 2005). The X10 removes fluid from the swollen knee by: creating a patient- set pain- free safe range of motion in which the machine can repeatedly flex the knee using only the patient- set pressure, the maximum pressure that did not cause pain. Critical to the successful fluid removal, the machine slows the bending of the leg near the ends of the patient- set range of motion and actually dwells there, without moving allowing fluid to leave the knee. The X10 is so efficient at removing fluid from the knee that the pressure required to flex the knee for the initial patient- set range of motion decreases within a 30- minute session allowing the patient to increase their range of motion within a session. Patients typically gain three to 10 degrees range of motion per day for the first week of recovery (Roubal and Freeman in review). In addition to being a therapeutic device, the X10 device also measures the angle of extension and flexion with every stroke, and the device can be used to strengthen both the quadriceps and hamstring muscles and measure their strength as well. The X10 can strength muscles both isometrically and eccentrically at different angles. The pressure sensor on the machine then records the pressure the patient generates.

5 MATERIALS AND METHODS Patients are trained by a coach to use the X10 and then use it on their own with telemedicine supervision and coaching on a regular basis. Patients are first trained to first establish a pressure that the machine uses to bend their leg, below their pain threshold, they then establish a pain- free range of motion within which the machine can work to remove fluid and thereby safely and painlessly increase their range of motion. Patients can also use the machine to strength their quadriceps and hamstring muscles on both legs. Treatment regimens are customized for each patient based on their abilities and progress. In Kevin s case, he used three different strengthening modalities: isotonic strengthening, eccentric strengthening, and eccentric stair exercises, supplemented with off- machine walking drills and stretches. In each of the programs, the exercises can be customized (resistance weight, time and angle of exercise) to achieve maximum comfort, protect the patient from pain, and ensure maximum progress. The details of Kevin s settings, along with his exercise schedule, are described below (Table 1). isotonic strengthening Started on 3/11, every other day, both legs three sets at 3 lbs. pressure. (Right leg with one set for 2nd and third sessions, left leg - three sets for first four days). Isotonic Exercises began at 10º and 110º but that range was too much. Starting on 3/26, we changed that to 45º to 110º and both legs switched to two sets while remaining at 3 lbs. pressure. On 4/9 he switched to one set every third day at 10 lbs. pressure. On 4/14 he went to 8 lbs. pressure. On 5/10 he went to 9 lbs. pressure. eccentric strengthening Started 3/26 - both legs one set every other day at 6 lbs. pressure. He did this on the same day at his Isotonic. Eccentric Exercises began at 10º- 110º but that was too difficult. Kevin switched to at two weeks and this never changed. On 4/9 he switched to one set for both legs every third day at 9 lbs. pressure eccentric stair Started 3/31 Kevin started on his off day from other exercises and did two sets at 6 lbs. pressure during days he was not doing Isotonic or Eccentric. On 4/9 he switched to a single set every third day at 9 lbs. pressure. The same day as the other exercises.

6 outside walking At first the patient could only walk in his house with two canes or a walker in his slippers. Then he did the same with sneakers on; he eventually walked in his work boots. After a week Kevin then took these exercises outside in the neighborhood and walked every day for six weeks. walking drills Heel Walking Tippy Toe Walk High March Small Lunge Backward Walking Runway Walk Weight Shift stair exercises Starting on 3/31, the patient did the one stair in the house every day - went up and down - started sets of 5, 10 and then to sets of 20 eventually. The exercises consisted of taking a step up, and then step back down to get feel of knee with all the weight. He repeated this going up curb and down curb on both legs around the block - two canes, then one cane then no canes for six weeks.

7 RESULTS Kevin began using the X10 machine on March 10 th, 2015, below are his initial and final assessment on ROM, the Tinetti (Tinetti et al. 1986), TUG (Mathias et al. 1987, Podsiadlo and Richardson (1991) and WOMAC (Quintana et al. 2006, Riddle et al. 2012) tests (Table 2). During Kevin s recovery we also kept track of his range of motion that we summarized weekly (Figure 1). Kevin s extension fluctuated dramatically until week 7, and by week 11 he had reached a consistent 0. Clearly, Kevin had a dramatic gain in ROM during week 7 (Figure 2) and thereafter. After week 7, the within week variation declined as he solidified his ROM at 130. Regaining range of motion is prerequisite to gaining strength (Moffet et al., 2004, Meier et al., 2008, Holms et al. 2010, Ebert et al., 2014, Roubal and Freeman in review). Range of motion is an indicator of residual fluid in the knee capsule, which dramatically reduces muscle activation (A. Young, 1993). In addition, Kevin was provided with a FitBit, which measured his activity, steps, joules expended, and the amount of time he was sedentary or active (Figures 2,3, 4) We conducted strength tests on March 15 th, April 17 th, April 29 th, May 15 th and June 14th on Kevin s right leg, (Figures 5 and 6) and on April 29 th and June 14 th on his left leg (Figures 7 and 8). April 29 th. The data for the right leg show Kevin doubled his March 15 th strength by April 29 (week 7). The right leg increased in strength still more by June 14. The left leg doubled in strength from the end of April, to mid- June. We also measured Kevin s pain, on a ten- point scale on the above dates, and we measured his pain at various angles and averaged those values for each of those dates. On March 15 th Kevin averaged 3.4 and 3.2 for the right leg quadriceps and hamstring pain. From April 29 th (week 7) onward Kevin recorded no pain for either leg or either muscle. The graphs that show activity all have common features. Kevin reached a peak during the fifth week, and it appears he over did it that week. A trough and then the resumption of continued improvement follow the peak at week 5 from week 7 onward - with minor oscillations. Interestingly, Kevin indicated that he was pain- free from week 7 forward, allowing him to focus on strength and returning to his normal life.

8 On May 18 th Kevin was able to return to work 12 days before his deadline, and after only 10 weeks of using the X10. Kevin did so well his first day back that he actually worked overtime. Despite achieving his goal of getting back to work, Kevin continued to use the X10 further strengthen and stabilize his knee until June 14 (14 weeks total therapy). DISCUSSION Kevin was not a typical patient because of his repeated setbacks. One would have to consider Kevin as one of the patients least likely to have a successful recovery. Each time Kevin had to stop therapy his progress was not simply placed on hold, but rather his range of motion and strength would decline. Moreover, Kevin ultimately rehabilitated himself at home, without physical therapists. The typical TKA patient undergoes surgery, followed by time in a rehabilitation facility, skilled nursing center, or as an outpatient in a physical therapy facility. Ultimately, the process can take three or more months, and doctors typically follow up with the patient at three and six months and a year (González et al, 2007). Kevin is also atypical for X10 patients. The typical X10 patient begins using the X10 within the first five days following surgery, and gains 3 to 10 degrees or ROM a day during their first week of using the X10. By three weeks of use, 80% of X10 users have achieved more than 110 degrees of ROM (Roubal and Freeman in review). Kevin began using the X10 roughly 9-10 months following surgery and thus was an extremely suboptimal patient. Nevertheless, Kevin began using the X10 to its fullest and made dramatic gains in strength and within seven weeks, dramatic gains in ROM, which led to even greater gains in strength. The FitBit chronicles consistent progress in parameter important to Kevin returning to work. Kevin basically barely walked in his first two weeks, and yet from three weeks on Kevin was taking thousands of steps a day he became progressively more active, less sedentary and burning more calories. Kevin was clearly a highly motivated patient. Nevertheless, if he had been forced to rely upon conventional physical therapy, rather than the X10, it is doubtful that he would have retained his employment and been restored to his normal life.

9 CONCLUSION The X10 provides a complete knee rehabilitation modular unit that can be used in a patient s home with only telemedicine supervision and as- needed coaching visits to configure the machine, introduce new exercised and provide motivation REFERENCES Ebert JR, Munsie C, Joss B. Guidelines for the early restoration if active knee flexion after total knee arthroplasty: implications for rehabilitation and early intervention. Arch Phys Med Rehabil Jun; 95 (6): González Della Valle, A., Leali, A., & Haas, S. (2007). Etiology and Surgical Interventions for Stiff Total Knee Replacements. HSS Journal, 3(2), Holm B, Kristensen MT, Bencke J, Husted H, Kehlet H, Bandholm T. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty. Arch Phys Med Rehabil Nov; 91 (11): Mathias S., Nayak USL, Isaacs B. Balance in the elderly patient: The "Get-up and Go" test. Arch Phys Med Rehabil 1986; 67: Meier W, Minzer RL, Marcus RL, Dibble LE, Peters C, Lastayo PC. Total knee arthroplasty: muscle impairments, functional limitations, and recommended rehabilitation approaches. J Orthop Sports Phys Ther May; 38 (5): Mizner R, Petterson S, Snyder- Mackler L. (2005). Quadriceps strength and the time course of functional recovery after total knee arthroplasty. Journal of Orthopedic Sports Physical Therapy. Vol 35, Number 7. L Moffet H, Collet JP, Shapiro SH, Paradis G, Marquis F, Roy L. Effectiveness of intensive rehabilitation on functional ability and quality of life after first total knee arthroplasty: A single-blind randomized controlled trial. Arch Phys Med Rehabil Apr; 85 (4): O Driscoll, S.W.; Giori NJ. (March/April 2000). Continuous passive motion (CPM): theory and principles of clinical application. Journal of Rehabilitation Reseach and Development. 37:

10 O Driscoll SW, Kumar A, Salter RB. (1983). The effect of continuous passive motion on the clearance of a hemarthrosis from a synovial joint; and experimental investigation in the rabbit. Clinical Orthopaedics. 176L Podsiadlo D, Richardson S. The Timed Up & Go: A test of basic functional mobility for frail elderly persons. J Am Geriatr Soc 1991; 39: Quintana, Jose; Escobar, Arostegui, Bilbao (January 2006). "Health- Related Quality of Life and Appropriateness of Knee or Hip Joint Replacement". Archives of Internal Medicine 166: Riddle, Daniel L.; Stratford, Paul W. (13 April 2012). "Body weight changes and corresponding changes in pain and function in persons with symptomatic knee osteoarthritis. A cohort study". Arthritis Care & Research 65 (1): Roubal, P. J. and D. C. Freeman (in review). Are Computer-Controlled, Pressure Modulated Knee Rehabilitation Machines Valuable Following Knee Arthroplasty? Archives of Physical Medicine & Rehabilitation Tinetti, M.E.; Williams, T. Frankin; Mayewski, R. (1986). "Fall risk index for elderly patients based on number of chronic disabilities". American Journal of Medicine 80 (3): Young A. (1993). Annals of the Rheumatic Diseases. Current Issues in Arthrogenous inhibition. 52:

11 FIGURES & TABLES 20.0 Figure 1. Extension for Right and Left Leg vs Weeks On X Degrees Extension Weeks On X10 EXT Right EXT Left

12 Figure 2 Average Steps/Day Steps/Day 14,000 12,000 10,000 8,000 6,000 4,000 2, ,661 10,885 9,622 8,979 7,248 7,837 6,040 5,828 7,492 8,599 2,793 3, Weeks

13 Figure 3 Sedentary and Active Minutes vs Week on x10 Average Dairly Minutes Weeks on X10 Sedentarty Light Activity

14 Figure 4 Mean Kilojoules Burned/Day Kilojoules Weeks on X10

15 Figure 5 Right Quadriceps Strength (Newtons) vs Angle Force (N) Mar Apr Apr May Jun Angle

16 Figure 6 Right Hamstring Strength (Newtons) vs Angle Force (N) Mar Apr Apr May Jun Angle

17 Figure 7 Left Quadricep Strength (Newtons) vs. Angle Force (N) April 29th 14- Jun

18 Figure 8 Left Hamstring Strength (Newtons) vs. Angle Force (N) Angle 29- Apr 14- Jun

19 LEGENDS Figure 1. Kevin used the range of motion component of the X10 three times a day for 10 weeks. Here we report the weekly means and standard deviation of extension for each week Kevin was on the X10 for both legs. The right leg was the leg damaged during earlier physical therapy. Clearly, Kevin made rapid progress after week 7 Figure 2. Kevin s FitBit recorded his number of steps automatically allowing us to download and chart the data. Clearly, from his first week of using the X10 Kevin began walking more steps, which is apparently a more sensitive measure of his progress than ROM. Kevin, needed to walk an average of 10,000 steps a day to complete his normal work tasks and surpassed this level by his 11 th week on the X10. Figure 3. Kevin s minutes of light activity and sedentary time were recorded by the FitBit. Kevin consistently became more active and less sedentary as the weeks on X10 increased. Figure 4. Kevin increased the number of kjoules burned per day beginning with his first day using the X10. Ultimately increasing his energy output by 50% over the course of 14 weeks. Figure 5. We measured Kevin s right leg quadriceps strength (Newtons) at angles ranging from 0 to 120 degrees at 10 degree intervals on five different dates. It is clear that Kevin began increasing strength and the range over which his quadriceps could exert measurable force with each successive measurement. Figure 6. We measured Kevin s right leg hamstring strength (Newtons) at angles ranging from 0 to 120 degrees at 10 degree intervals on five different dates. It is clear that Kevin began increasing strength and the range over which his quadriceps could exert measurable force with each successive measurement. Figure 7. Kevin made remarkable gains in strength of his left quadriceps from April to June. Figure 8. Kevin made tremendous gains in the strength of left hamstring from April to June.

20 Table 1 Week of: 3/9/2015 3/16/2015 3/23/2015 3/30/2015 4/6/2015 4/13/2015 4/20/2015 4/27/2015 5/4/2015 5/11/2015 5/18/2015 5/25/2015 6/1/2015 6/8/2015 6/15/2015 6/22/2015 6/29/2015 Treatment Week Treatments ROM - right ROM - left Isotonic - right Isotonic - left Eccentric - right Eccentric - left "Stair Prepare" - right "Stair Prepare" - left Home Exercises Walking Drills FitBit Assessments Strength Assessment - right 3/15 4/17 4/29 5/15 6/14 Strength Assessment - left 4/29 6/14 WOMAC 3/10 6/14 Tinetti 3/10 5/14

21 Table 2 March 15 th, 2015 May 14 th, 2015 ROM TINETTI BALANCE 8/16 16/16 TUG 25 seconds 8 seconds WOMAC 80/96 46/96