Getting Microprocessor KAFOs to the Right Patients

Studies have shown that users of microprocessor KAFOs are less likely to fall, feel more confident while wearing their devices, and are more likely to try activities they once feared. This is accomplished while giving the patients an almost natural gait. The experts we spoke with say the technology is promising, but there are still hurdles to overcome for reimbursement from private insurers. The Evolution of KAFOs Despite advances in microprocessor prosthetic knees, users of KAFOs have previously been required to use designs that locked their knees, gave them an unnatural gait, or could even cause them to fall on uneven terrain. “There were a lot of developments in technology for the prosthetic knees that allowed for more safety and function, and that development didn’t happen in orthotics. So we made the big leap,” says Andreas Kannenberg, MD, PhD, executive medical director, Ottobock North America, maker of the first microprocessor KAFO, the C-Brace, which was introduced in 2012. KAFOs have evolved, but each iteration has its own drawbacks. The traditional brace design is a locked KAFO (LKAFO) in which the knee is permanently locked except when the user is sitting. The locking prevents the knee from giving way but leads to asymmetrical gait patterns and requires a large expenditure of energy as the patient walks with a stiff leg. Users of LKAFOs statistically have a 79 percent noncompliance rate, says Chris Toelle, CO/L, director of Clinical and Scientific Affairs, Hanger Clinic. “They could only use them for a certain amount of time before they ran out of energy.” The locked design also requires users to have upper-limb support to provide balance, and that interferes with their independence as it prevents them from using their hands, he says. The next development in KAFO designs was the posterior offset KAFO (PO-KAFO), which positions the knee joint posterior to the axis of rotation of the natural knee joint. This design allows the knee joint to move freely, but the offset position can lead to overcompensation on the sound side of the body that could lead to lower back pain or overuse of the compensating limb to make up for the alignment change, Toelle says. The introduction of stance control orthoses (SCO) provided another option that allows users to have a more natural alignment by locking during the stance phase and moving freely during the swing phase. Both the SCO and PO-KAFOs can be problematic when the user is not on level ground, says Kannenberg. “The problems usually start when the patients walk on uneven terrain and have to negotiate ramps or stairs,” he says. “For those in the free swing phase, it makes it difficult for the patient to achieve stability and prevent the collapse and fall during the stance phase.” [caption id="attachment_263634" align="alignright" width="461"] The C-Brace automatically adjusts when users transition to sitting, or descending stairs, and is suitable for bilateral use. ©Ottobock[/caption] The advent of the C-Brace helped to overcome these challenges, Toelle and Kannenberg say. The C-Brace comes with a hydraulic knee that provides flexion and extension resistance that helps users have a nearly physiologic gait on all types of terrain. Microprocessor KAFOs also have a stumble recovery feature that can detect when a user has stumbled and locks the knee, which allows for a corrective step to regain balance. A 2023 study followed C-Brace patients for three months and found that their balance improved, and their fall risk decreased. 1 The number of falls decreased by 80 percent. In 2024, researchers released the results of an international registry of C-Brace users over the course of one year. 2 The registry, which followed patients under real-world conditions for a year, showed that users reported that their average number of falls from the previous six months was reduced by 91 percent. “The patients resumed activities that they didn’t do before because they were afraid of falling, and they have performed better on nonlevel terrain, so when walking on uneven terrain such as walking on slopes or walking on stairs,” Kannenberg says. Kannenberg says it makes sense that the 2024 registry had better results because patients had nine months more experience with the C-Brace than in the 2023 study. “That’s not surprising because they become more used to using the orthosis over time,” Kannenberg says. Toelle says the studies help prove that microprocessor KAFOs are safer than traditional designs. “Having this microprocessor technology to regulate the moments in the gait cycle, without having to compromise for alignment or locking someone’s knee, increased independent performance and mobility. The clinical studies show that the microprocessor KAFO is a safer device versus anything else we could provide in that specific space,” Toelle says. Pricing Microprocessor KAFOs and Their Alternatives Getting insurance coverage for microprocessor KAFOs has been a challenge, but there have been successes. Ottobock applied for an L-Code in 2018, and L-2006 was established in 2020. In 2022, the Centers for Medicare & Medicaid Services (CMS) established a fee schedule amount for L-2006, and the Durable Medical Equipment Medicare Administrative Contractors allowed for billing on a case-by-case basis in the Local Coverage Determination for AFOs and KAFOs in the same year. Getting to this point took time, persistence, and studies to prove the effectiveness of the brace, but coverage is still not guaranteed, he says. “They don’t explicitly say its covered and didn’t provide any criteria or requirements. But they allow for individual applications, and it is going relatively well if proper documentation is submitted,” Kannenberg says. “If the practitioner is able to explain the medical necessity for the patient, then Medicare beneficiaries can get a C-Brace.” Convincing private payers is taking even more time, he says. “With commercial insurances it is more tricky. They are more reluctant to cover the C-Brace.” He’s seen commercial insurance companies deny covering the L-Code outright, or they assign a payment amount that is too low for the orthotist to make a margin. “Sometimes they may even lose money,” Kannenberg says. Roger Marzano, CPO, CPed, vice president of clinical services, Yanke Bionics, Ohio, has seen firsthand the challenge of getting reimbursed. When he submitted a microprocessor KAFO claim three years ago, the insurer paid half of what he requested, and most of that money paid for the device and not his time or expense. “What we’re finding is that the technology is there, but the reimbursement level isn’t there,” he says. The patient had his device covered by workers’ compensation, but when that was fully paid out, he couldn’t afford to pay thousands of dollars to service it. “You can have the best technology in the world, but if no one is writing checks for it, then it doesn’t matter,” he says. The experience prompted Marzano to look for other solutions, and he was impressed by the 3D-printed Hercules KAFO by Icarus Medical. The device does not have the automatic adjustments or safety features of its microprocessor counterparts, but it does allow patients to increase the amount of resistance required to bend their knees, which is one of the main functions of the microprocessor braces, Marzano says. Also, the Hercules KAFO is much lighter and a fraction of the price, Marzano says. “You can’t have a Mercedes-Benz on budget insurance,” he says. “I have to live in the real world. The technology is wonderful, but I also have to think of the pocketbooks of my patients.” Kannenberg says that he and his team continue to work toward better insurance coverage. They are armed with the studies and plan to approach commercial insurance companies one by one as they do their annual policy reviews. “We provide all the information and all of the evidence that is available, and we are hoping they consider that when they revise their orthotic policy,” he says. Toelle is hopeful that as more studies are done and as the efficacy and safety of microprocessor KAFOs is proven time and time again, that commercial insurance companies will take note. “We’re slowly seeing their adoption…,” he says. “Our hope is that this should not be looked at as innovative technology or advancement of technology, but as an essential device for a specific person’s needs…like C-Leg has done for prosthetics and has become more commonplace to increase user’s everyday mobility. That’s what we hope happens with the adoption of the C-Brace.” The Right Patients for Microprocessor KAFOs [caption id="attachment_263635" align="alignright" width="335"] Users of the Tectus, which has a unilateral design, indicate through a fob or button for the device to increase resistance when sitting or using stairs. Photograph by Heather Swanson.[/caption] To get any reimbursement, including by CMS, patients have to meet certain requirements for the devices. They have to prove that they would benefit from the device and have the mental ability to use it. Above that, there are certain physical characteristics that disqualify patients from use. Some prospective users have significant hip or knee contractures with tight ligaments and muscles that can’t fully straighten when standing. If those contractures cross ten degrees or more, then the device won’t work as intended. “What ends up happening is that it makes it difficult to get the knee joint aligned to operate the microprocessor consistently,” says Todd O’Hare, MSPT, CPO, clinical specialist, Blatchford. The contractures may be alleviated through physical therapy, at which point the patient can be reconsidered for use. Also, O’Hare says, someone with increased muscle tone might not be a good fit. “That is going to be affecting their antigravity muscles in their leg, and those are the ones that keep us upright. For instance, the quadriceps are an antigravity muscle, so if we’re trying to get the knee to release from stance to swing and their quadricep is wanting to stay in extension, then they’re going to be fighting each other.” Both Ottobock and Blatchford require potential users to try a test brace to help evaluate their candidacy. Among other things, the patient has to prove that they have trunk control and the ability to power one leg over the other to take a step. Once the patient has used the test device and a brace is approved, the orthotist will cast the patient and receive a diagnostic check brace. “The check brace, or diagnostic orthosis, is necessary to ensure proper trimlines, length, and that it’s comfortable for the patient because it is form fitting. It is also important to ensure the accuracy of knee and ankle alignment,” O’Hare says. “Once you go to the next step, the definitive, there’s not a lot of change you can make. If the knee joint or ankle joint are not aligned accurately, the orthosis may not function properly.” In some ways, fitting a microprocessor KAFO can be more challenging than fitting a prosthetic leg with a micro-processor knee, Toelle says. “The difference with an above-knee amputee is that the prosthetist is replacing the limb that has been removed,” he says. “Because of this, the prosthetist has more leeway in alignment and more of an opportunity to reposition someone, because they’re building the limb from the ground up. With a KAFO, we’re working with an existing limb, and we must gather details and an estimated range up front because we can’t adjust as much throughout the fitting process.” Differences in Microprocessor KAFOs There are two leading microprocessor KAFOs on the market: Ottobock’s C-Brace and Blatchford’s Tectus, which launched in 2023. The braces have many similarities, but there are differences. The Tectus has adjustable knee extension assist, which is a spring that helps accelerate the knee forward into extension when the knee releases from a stance into a swing. “That ensures they are getting more proper gait dynamics during swing,” O’Hare says. “You can have an individual who might be a little bit weaker and because of that extension assist, they could possibly utilize our brace more easily.” The C-Brace, however, is more automated. When a patient is sitting or going down a stair, the device is able to automatically adjust without the patient having to think about it. “It can recognize if you are walking down the stairs or on level ground,” Kannenberg says. For the Tectus, to increase resistance during sitting or stepping, users have to indicate that to the device, whether by using a fob or pushing a button on the device itself. “That’s a safety design so they know for sure that while they’re going down the stairs, it always stays in the stair mode, or while they’re going from standing to sit that they know they’re in sitting mode,” O’Hare says. Another difference is that the Tectus has a unilateral design, which means a patient can only wear one. The C-Brace allows patients to wear it on both legs. “A C-Brace is commonly used for people who require bilateral care,” Toelle says. Both models have a stumble recovery feature and allow for controlled knee flexion during weight bearing, which is needed to lower a body down a slope or a stair on the orthotic leg. This feature is critical, Kannenberg says. “That is the single most important advancement in orthotic technology,” he says. “Especially compared to patients who use the traditional stance control orthosis, may it be mechanical systems or electronic systems…none of them have a stumble recovery feature.” As both designs improve and as other devices come on the market, patients will benefit as researchers learn and improve the designs. At Hanger Clinic, Toelle says they’ve cared for patients with more than 350 different types of diagnoses including polio, Charcot-Marie-Tooth, spinal cord injury, and traumatic brain injury, and they approach care by presentation instead of specific diagnoses. “Now that we’ve learned what we have, some of the new devices that are coming are only going to improve patient care and help us provide care to a broader spectrum of people.” Maria St. Louis-Sanchez can be contacted at msantray@yahoo.com . References Ruetz, A., et al. 2024. A microprocessor stance and swing control orthosis improves balance, risk of falling, mobility, function, and quality of life of individuals dependent on a knee-ankle-foot orthosis for ambulation. Disability and Rehabilitation 46(17):4019-32. Lundstrom, R. L., et al. 2024. The C-Brace® microprocessor-controlled stance and swing orthosis improves safety, mobility, and quality of life at one year: Interim results from a prospective registry. Journal of Rehabilitation and Assistive Technologies Engineering11: 20556683241269539. 9 Aug. 2024, doi:10.1177/20556683241269539 Featured image: ©Ottobock

Getting Microprocessor KAFOs to the Right Patients

SURVEY SAYS: DEI and PhDs

Editor’s Note–April 2025

Editor's Note--April 2025

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Certified Prosthetist / Prosthetist-Orthotist (CP/CPO) Gates Prosthetics + Mobility Clinic — Mountain Home, AR

Clinic Manager – Certified Prosthetist Orthotist (CPO) – Rogers, AR

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Getting Microprocessor KAFOs to the Right Patients

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SURVEY SAYS: DEI and PhDs

Editor’s Note–April 2025

Editor's Note--April 2025

O&P JOBS

Certified Prosthetist / Prosthetist-Orthotist (CP/CPO) Gates Prosthetics + Mobility Clinic — Mountain Home, AR

Clinic Manager – Certified Prosthetist Orthotist (CPO) – Rogers, AR

CPO

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