Todd DeWees, MHA, CPO, manager, Shriners Hospitals for Children, Oregon, recently treated two young boys with proximal femoral focal deficiency (PFFD), a rare congenital genetic defect in which the femur is abnormally short and underdeveloped. Because PFFD presentation ranges from a slight leg length discrepancy to the near-complete absence of a femur, there are a variety of solutions that are generally initiated in childhood depending on the severity of the condition, including rotationplasty, a Symes amputation, and prosthetic or orthotic interventions.
Both boys DeWees treated started with extension prostheses to help them when they reached the pull-to-stand phase and underwent revision surgeries around the age of four. One of the boys was converted to a PFFD-Syme-level prosthesis and the other underwent a rotationplasty.
While the children’s treatment followed different paths, “both are now highly functional and can keep up with their peers,” says DeWees. “While both retain a Trendelenburg gait due to hip involvement, they will likely undergo future hip reconstruction to further stabilize the joint and improve their walking patterns.”
DeWees says there are two primary challenges with PFFD: anatomical variety and the frequency of associated diagnoses. The former can range from a short femur with a stable hip to the entire absence of the hip socket and femoral head. “This creates a massive spectrum of functional abilities,” he says.
The associated diagnoses, which can include fibular hemimelia, joint instability, foot deformities, and other bone and muscle disorders, adds layers of complexity to every treatment plan, DeWees says.
Michelle Hall, CPO, lead prosthetist and O&P residency director, Gillette Children’s, Minnesota, and 20-year veteran in the O&P profession says, “Similar to cerebral palsy, children and adults with PFFD do not all present similarly and there is variance in the severity of the deformities. Some patients’ hips are always dislocated, while others dislocate on occasion or not at all.”
Markers of PFFD
PFFD is often classified from class A to D, with class C and D more commonly leading to rotationplasty and prosthetic management. “Limb reconstruction and lengthening are pursued when the goal is to preserve the limb,” says Greg Sachs, CPO, PT, practice manager, Hanger Clinic, Maryland. “Success is highly individualized and based on family priorities, functional goals, and the child’s long-term well-being.”
“In general, PFFD refers to a short, a very short, or absent femur, often occurring with other limb differences, and at times, there may be no true hip joint, no actual connection between the femur and the pelvis,” says Don Cummings, CP/L, former director of prosthetics, Scottish Rite for Children, Texas. Cummings retired in March after an O&P career that spanned more than 40 years.
PFFD is relatively rare, typically occurring about once in every 100,000 live births. However, Elizabeth Petrovic, CPO/L, Hanger Clinic, Illinois, who has been treating children for more than five years, says while comparatively rare, PFFD may not be as uncommon as often thought.
“It may actually be more common than we think because it presents across such a wide spectrum of severity. In our clinic we’re fortunate to see a number of these cases, largely because we’re located near a pediatric orthopedic specialty hospital,” she says. “That environment has given us the opportunity to work with many patients with congenital limb differences and develop experience treating PFFD.”
DeWees also works at such a specialty pediatric center where his practice is highly concentrated. “PFFD accounts for about 2-3 percent of our 6,000 annual patient contracts, making it a common clinical focus for us,” says DeWees, who has worked in O&P for nearly 25 years.
A Range of Treatment Needs
Sachs says treatment varies widely because PFFD presentation varies widely from child to child. Sachs spent ten years as a physical therapist in physical medicine and rehabilitation, where he worked directly with Dror Paley, MD, FRCSC, an orthopedic surgeon, CEO, founder, and medical director, Paley Orthopedic and Spine Institute, and his limb lengthening and reconstruction team, where Sachs cared for a number of patients with PFFD.
“Some patients are managed with bracing and shoe lifts while undergoing limb lengthening and hip reconstruction,” he says. “Others benefit from a prosthesis, such as a foot-over-foot design, which helps stabilize the knee, support the thigh, and provide a more functional gait during growth and surgical stages.”
Sachs says while outcomes depend on the child’s goals, “many achieve improved mobility, stability, and independence through a combination of reconstruction and prosthetic support.”
Cummings agrees. “Each case is different,” he says. “There is no single best approach.”
What helps when treating PFFD, Cummings says, is for the parents to learn about all the options, from the possibility of surgery to prosthetic options. He says that the primary challenges for more severe cases are an unstable hip, malrotation of the limb, and limited and relatively weak musculature to flex and extend the hip, which then impacts the patient’s ability to control a prothesis. Other challenges include a significant length discrepancy between the affected and sound side, a foot that can be at or above the level of the opposite knee, and, in extreme cases, a knee that is just below the pelvis.
“Each case has to be taken individually,” Cummings says. “And it is often better to wait until the child is walking on a prosthesis or an orthosis and to have their bony anatomy be more visible on an x-ray, for example, before a decision can be made.”
Petrovic says understanding the patient’s unique PFFD presentation is vital when developing a treatment plan. “Because patients with PFFD don’t have typical anatomy, assessing joint stability and functional strength becomes essential in determining the most effective socket design,” she says. “There are multiple surgical pathways, and the residual anatomy can present in dramatically different ways from one patient to the next. It requires a deep understanding of anatomy and biomechanics. You have to determine which joints are truly functional, which ones need support, and how to design a prosthesis around that.
“Designing prostheses for this population is something I genuinely enjoy because it challenges you to think creatively and use the full range of prosthetic solutions. Every case requires a detailed evaluation and a customized approach, which is part of what makes treating these patients so rewarding.”
Hall agrees that the variety of PFFD presentations can make it more complicated when fitting a prosthesis. “Additionally, the hip instability can also become problematic as the child grows and gains weight over time,” she says. “Many of our adults with PFFD who had a foot ablation in childhood with greater hip instability typically end up having their ‘knee’ fused so they can be fitted with a transfemoral-level prosthesis. Those are the sockets that have to come more proximal at the lateral and posterior aspects to stabilize the hip.”
The anatomical differences can also change significantly as a child grows, says Sachs. “Families often explore many treatment paths, leading to a range of approaches,” he says. “Although the hip is typically the most affected area, the knee and ankle are frequently involved as well. A common progression may include shoe lifts, early prosthetic use, surgical reconstruction, and later prosthetic intervention.” Options may include rotationplasty, fusion with amputation, or continued reconstruction, depending on the patient’s PFFD classification and goals, Sachs says.
Impact on Daily Life for Children and Their Families
PFFD can have impact activities of daily living for children and their families in a variety of ways.
Hip instability is often the most significant hurdle, says DeWees. “It causes gait deviations that are energy-inefficient, making daily activities more tiring. This often leads to frustration or withdrawal from physical play.” He adds that the distinct walking pattern associated with a Trendelenburg gait, which appears as a waddling or lurching gait, can draw unwanted attention that is socially difficult during childhood and adolescence.
PFFD can influence many aspects of daily life, including physical ability, psychosocial adjustment, and lifestyle, says Sachs. “Children may face challenges related to gait, endurance, and body image, and families often navigate complex medical decisions over many years,” he says.
“Each case is very individual, so it is hard to say how PFFD affects a person’s daily life,” Cummings says. “But in general, they’ll probably be using some type of device ranging from a shoe lift, brace, extension prosthesis, rotationplasty prosthesis, or something similar to a transfemoral prosthesis [if their foot is removed].”
There is one advantage patients with PFFD have with prosthesis use, Petrovic says.
“PFFD patients have the ability to distal-end bear, which can be very helpful for prosthetic design,” she says. “It can also make daily activities easier when they’re not wearing the prosthesis. With the right support and design, many of these patients lead very active lives.”
“It’s similar to any other kid with limb loss or difference who uses a prosthesis,” Hall says. “Most are really successful using their prothesis on a daily basis for whatever activities they want to do.”
Support, Follow-Up, and Creativity
Successful care requires close collaboration among the rehabilitation team, including surgeons, therapists, prosthetists, and the patient, says Sachs, who adds, “The most important factor is psychosocial acceptance, both for the family and the child,” he says. “When children feel supported, confident, and included, they adapt remarkedly well to their physical differences and treatment journey.”
What DeWees has found what works best in terms of treating PFFD is normalization. “A child’s success depends largely on the people around them,” he says. “When a family treats a child with PFFD just like any other sibling, that child develops a foundation of self-confidence.”
DeWees says it’s critical to build trust with the child and the family. “These children often undergo multiple painful procedures. If they view their clinician as another source of pain, they won’t fully participate in treatment, which limits their long-term function,” he says.
While the child will still face physical obstacles, he says, “A positive self-image will make them better prepared to overcome those challenges,” he says.
Success for the patient and the practitioner also requires professional humility, DeWees suggests. “Even with over 20 years of experience, I still reach out to colleagues when I encounter a unique challenge. In O&P, it’s natural to want to have all the answers, but the best outcomes come from knowing when to seek a second opinion.”
Hall says routine follow-up plays a part in treating PFFD. “We’ve diligently provided specific prosthetic care to these patients,” she says. “It’s important, similar to most with limb loss or difference, that we’re routinely following up with these patients to accommodate growth and tailor the care to each specific patient. We meet the family and kids where they’re at and adapt as they grow and develop.”
In general, children with PFFD can live an active lifestyle; many will be able to run and play sports. “Many will use a prosthesis or an orthosis, but because this condition occurs at birth, children are resilient and can adapt incredibly well to whatever combination of surgeries, orthoses, shoe lifts, or prosthesis may be required,” Cummings says.
In addition to having an experienced medical team, Cummings also agrees that strong family and peer support plays a crucial role. “Having a loving family support group that encourages the child to be as active as possible and to find creative solutions to any mobility or social challenges they encounter is probably the best way of helping the child to be successful,” he says.
Like her colleagues, Petrovic stresses a solid regimen of follow-up care and believes in actively involving patients and their families in the decision-making process.
“When patients understand their options and feel like they’re part of the process, they become much more engaged in their care. The collaboration often leads to better outcomes,” she says. “For younger patients, family support makes a tremendous difference. When families are engaged and supportive, kids tend to adapt incredibly well.”
Betta Ferrendelli can be contacted at betta@opedge.com.
Opener image: LightFieldStudios/envato.com
