Mending knees with Palms
By Erin Miller
While many people use their cellphones and PDAs largely for socializing and entertainment, some science and medical professionals utilize similar devices to track and analyze patient-reported outcomes following surgery.
Nearly 5 billion people worldwide carry cellphones, and one-third of U.S. adults own a smartphone. Having technology at our fingertips around the clock means texting relatives across the globe, ordering takeout with a few finger swipes, Tweeting the latest news, and keeping tabs of sports scores in real time.
But for medical professionals, the uses of this technology extend far beyond recreational. Dr. Steve Tippett, chair of Bradley’s Department of Physical Therapy and Health Sciences, teamed up with DePuy Orthopaedics in Warsaw, Ind., and seven clinics across the country to study the effectiveness of using Palm PDAs to track patients’ recovery after double-knee replacement.
This study was part of a larger study of patients undergoing two simultaneous knee replacements. One type of prosthesis was implanted in one knee, and a different prosthesis was placed in the other to analyze if mobility and recovery after surgery varied from knee to knee and whether patients’ pre-operative expectations met their post-operative functions.
“Historically, patient-reported outcomes have been difficult to track because compliance with paper diaries is poor,” Dr. Tippett says. “So to get more meaningful and reliable data for the double-knee replacement study, we had patients use a preprogrammed Palm device to enter their progress on a daily basis.”
According to the researchers’ results published in The Journal of Bone and Joint Surgery, paper diaries make patients active participants in providing data, but reliability “is only as good as the patient is in entering data.” Doctors or physical therapists can’t validate the time when a patient completed a diary entry, the study found.
The other widely used form of collecting post-operative recovery data is through outcome scoring systems. However, these provide only a snapshot of the patient at predetermined points following surgery and give little insight about a patients’ day-to-day recovery, according to the report.
“The big thing with using the Palm devices is that for the first time, we were able to look at the patients’ progress on a daily basis,” Dr. Tippett says. “Usually they go to the doctor once a week, and we get little pieces of information, whereas the Palm devices give us ongoing, reliable information about how patients feel, how much pain medication they are taking, and all kinds of other data we don’t normally get to track every day. It’s a really nice way to look at daily progress after total-knee replacement.”
Researchers tracked the progress of 93 patients between the ages of 40 and 73 who underwent double-knee replacement. Prior to surgery, each patient was trained on how to use the Palm device, then answered the same questions every day for six weeks, including location and severity of pain; pain medications and other methods of pain management; and the degree of difficulty they had performing various functions like climbing stairs, doing chores, putting on socks, getting in the bathtub, and driving. Within the first five weeks after surgery, 82 percent of patients entered their data daily after the initial few days of recovery, and in a follow-up survey, patients across all ages said the electronic documentation was user friendly.
“The age group participating in this study is not really computer savvy, and the major question we asked ourselves was ‘Can they do this?’” Dr. Tippett says. “Well, they did it, and they weren’t afraid of it. Their compliance was sky high compared to paper diaries.”
With a larger amount of more reliable data, Dr. Tippett and his fellow researchers were better able to answer the study’s primary question: Do patients’ pre-operative expectations match their post-operative satisfaction?
The data revealed that while patients steadily progressed from a walker to a cane to crutches over the first six weeks following surgery, many still were not able to perform basic day-to-day tasks to their liking. For example, pre-operative expectations to descend stairs six months after surgery were met in only 53 percent of patients.
“With this study, we found that even a year after surgery, patients’ pre-op expectations didn’t match their post-op functions,” Dr. Tippett says. “And we wouldn’t have learned that had it not been for the reliable daily data collected with the Palm devices.”
With the success of this study — the first to the authors’ knowledge to collect orthopedic patients’ outcomes via handheld electronic devices — Dr. Tippett anticipates this method will be more widely used in the future. “As technology gets easier and more affordable, I think we will see a lot more of this.”
A leg up on inventions
Sports injuries — one in football, the other in baseball — can be partially credited for two Bradley alumni adding “inventor” to their resumes.
Bob Horst ’75 and Dr. Lindsey Rolston ’85 come from very different academic backgrounds — Horst, electrical engineering, and Dr. Rolston, orthopedic surgery — but each has developed a device to help patients regain mobility in their legs.
Piloting the Bionic Leg
Horst, who lives in San Jose, Calif., injured his knee while playing sandlot football in high school. Not satisfied with his mobility on crutches, Horst set out to create something better.
In 2002, while working in computer systems design, Horst co-founded Tibion Bionic Technologies with a mission statement that satisfied his high school hope: “Advancing rehabilitation and mobility with innovative technology.”
Despite years of uncertainty about whether a noninvasive, computerized assistive device could have therapeutic value, the Tibion Bionic Leg was born. “We are the first to have a portable device like this,” Horst says. “What really makes ours effective is that it is intention-based. … It is unlike many robotic therapy devices in that it does not have a set of movement patterns or speeds, but continually reacts to the intended motion of the patient. This is a key reason the Bionic Leg is showing so much promise in rehabilitation.”
Tibion began shipping the Bionic Leg at the end of 2009, and there are now more than 30 units in use at therapy clinics across the country. The Bionic Leg is primarily used for stroke rehabilitation, but therapists are beginning to use it to help others with impaired mobility, including those recovering from knee and hip replacement surgery.
“Seeing patients benefit from our Bionic Leg is rewarding unlike anything else I have experienced,” says Horst. “It can be a very emotional experience to see a patient come to a clinic, put on the device, and start to regain their ability to walk.”
More than 2,000 miles away, in New Castle, Ind., orthopedic surgeon and former co-captain of the Bradley baseball team Dr. Lindsey Rolston took inspiration from his own injury to invent the Journey Deuce Knee System.
“I had a shoulder problem as a pitcher at Bradley, and orthopedics became a natural fit for me because of my experience with sports,” he says.
Launched in 2007, the Journey Deuce implant results in a quicker recovery by replacing only the two areas of the knee most commonly affected by osteoarthritis, the kneecap and medial compartment (the inner portion of the thigh and shin bone). The surgery preserves parts of the knee often not affected by osteoarthritis.
“The outside part of the knee was normal about 50 to 70 percent of the time, but I had to take it away with conventional total-knee replacement,” Dr. Rolston says. “Also the anterior cruciate ligament, which we try to preserve in athletes, had to be cut out with the old replacements.”
After submitting a patent, Dr. Rolston contacted Smith & Nephew Orthopedic Reconstruction and teamed up with the company to produce and distribute the implant. Worldwide, doctors have performed about 10,000 surgeries using the Journey Deuce Knee System.
Dr. Rolston foresees developments to the implant in the near future, including customization for the wide array of body types, as well as improvements that would allow patients to run following surgery.
“We currently use cement and when people run, they can crack the cement. But with this new porous metal we are working with, bones will grow into the metal and increase durability,” he says.
Affiliated with the Henry County Center for Orthopedic Surgery & Sports Medicine, Dr. Rolston says his first patient returned a year later to have her second knee replaced. “I figure that’s a testament to the device,” he says.