Congenital femoral deficiencies present significant challenges in the rehab arena
Emily Rade, PT, DPT
|Vol. 21 • Issue 11 • Page 28
Eva Davidson arrived in our outpatient clinic, bouncing and holding her mother’s hand, wearing a fixator on her right lower extremity and a seven-inch shoe lift on the same side.
Eva, like other patients with congenital femoral deficiency, began outpatient physical therapy the day following acute-care discharge. At this point, patients are in the latency period, having not begun lengthening or “pin turning,” and therefore, pain and spasticity are at a minimum.
Eva was diagnosed with congenital femoral deficiency (Paley Type 1b) at 6 months old. Formerly known as proximal femoral focal deficiency (PFFD), congenital femoral deficiency (CFD) results in an unstable hip and knee, as well as a considerable leg-length discrepancy. All patients with this condition have a congenitally short femur that grows at a slower rate than the normal side.
The birth defect occurs in about one in 40,000 live births, while the cause is generally unknown and not genetic.1The Paley classification is based on the severity of the deficient anatomy present at birth. There is a variety of pathology involving the development of the hip in these patients. At this point, the patient and family decide between non-operative and operative management of the deficiency.
Unlike the normal course of post-operative PT for orthopedic patients, limb-lengthening patients experience increased difficulty and decreased gain as time goes on. This creates a need to establish specific knowledge and protocol to successfully complete the achievable goal. In order to fully understand and appreciate the extent and focus of PT, one must have knowledge of the condition and surgical procedures performed on the patient.
Non-operative management of the leg-length discrepancy includes use of shoe lifts, orthoses and/or prostheses. The severity of the deformity is quite vast. Patients with CFD lack stability, mobility and integrity of the knee and hip joints. In addition to leg-length discrepancy, bony deformities, malorientation of the joint and soft-tissue contractures are often associated with this diagnosis.
Congenital abnormalities of the knee are also associated with CFD. The often-absent anterior and posterior cruciate ligaments lead to instability of the knee joint. The patella is often affected as well. Stability and joint integrity must be achieved in both the hip and knee for a successful lengthening to occur and thereby improve the patient’s mobility and function.1
The most successful approaches for achieving joint stability and integrity are the systematic utilitarian procedure for extremity reconstruction (SUPER) hip and knee procedures. These procedures should be completed six to 12 months before the lengthening. Lengthening may begin once ossification of the femur occurs. A year is typically needed between the SUPER hip and the lengthening procedures.
The majority of CFD patients require one or more lengthenings. The lengthenings should be spaced throughout childhood and completed prior to high school. Patients may safely achieve 5 cm to 8 cm of length with each lengthening. Limb lengthening is achieved by bone and soft-tissue regeneration. Lengthening occurs in two stages: distraction phase and consolidation phase.
When a bone is cut and pulled apart at about 1 mm per day, new bone regeneration occurs between the bone ends. The soft tissues also regenerate when distracted at a slow rate; however, if the rate of distraction is too fast, the bone may fail to develop, and muscle contractures and/or nerve paralysis may occur. In the same respect, if the lengthening rate is too slow, premature consolidation may occur. Eva had this complication, which stopped the lengthening process until the bone was re-broken with an additional unplanned surgery.1-3While the bone is fixed by the lengthening device and must elongate at the rate of distraction, the muscles, which are fixed by the device, will try to avoid getting longer and regenerating new muscle tissue. This can be done two ways. Since muscles can alter the position of a joint, they can avoid elongation by flexing the joint they span. Muscle is the only tissue that has a built-in mechanism to change its own length. For growth to occur, the muscle must be stretched multiple times a day. Steady gains in range of motion cannot be achieved during the lengthening process due to the constant growth in the length of the limb.
Shoe lifts and orthoses are used to aid in the patient’s ability to weight-bear through the limb and normalize gait pattern as part of rehab.
Knee and hip subluxation must be prevented during lengthening. To prevent stiffness and dislocation of the knee, the external fixator should be articulated across the knee and fixed to the tibia. This permits knee motion but prevents subluxation of the knee.
Pain should be minimal for patients throughout the day, and well-controlled with the appropriate medication. The follow-up therapy is extremely intensive and essential to the success of the lengthening process.4
The goal of therapy during the lengthening process is to maintain muscle length and joint range of motion. Therapy is essential to prevent joint stiffness and muscle contractures. The preferred regimen is for one hour each of land and aquatic therapy five times a week, combined with daily home stretching and an exercise program.
Signs of nerve stretching must be monitored throughout the treatment. The deep peroneal nerve is the nerve at greatest risk with femoral or tibial lengthening. Warning signs include pain referred to the anterior distal leg or dorsum of the foot with knee extension. If this does occur, the patient must undergo a nerve decompression at the neck of the fibula.5
The patient is assessed each session during the lengthening for knee subluxation, range of motion of the hip and knee, nerve function and pin-site problems. Patients are encouraged to weight-bear with or without external aids to their tolerance. Knee flexion must be maintained at greater than 45 degrees. If the knee flexion is 40 degrees or less, the lengthening is stopped and therapy intensifies. Knee ROM and stretching is required to allow the lengthening process to successfully occur and maintain the patient’s functional mobility.
A patient’s function is never sacrificed to gain limb length.3Patients use a knee extension bar nightly to prevent the development of a flexion contracture. Hip motion is maintained with increased attention to hip flexion and hip adductor contractures. Both can lead to a hip subluxation or dislocation. The muscles most prone to contracture are the quadriceps and hip adductors. Passive exercises are most important during the distraction phase.
Rehab is a critical and essential aspect of the limb-lengthening process. In order for the rehab component to be successful, the entire team, including the PT, patient and family members, must work together.
A typical PT session begins with moist heat to the posterior knee with the knee maintained in extension by propping the ankle on a bolster. Neuromuscular electrical stimulation (NMES) is applied to the quadriceps along with an active quad contraction. The electrical stimulation is used for both strengthening and fatiguing the quadriceps, which in turn decreases the muscles’ ability to resist during the knee flexion stretching. Muscle spasms are very common during the stretching exercises.
Play is incredibly important to help build a rapport and trust with the young patients. Eva often engaged in play with her mom or therapist. NMES can be intimidating for children because it produces a scary/unusual sensation. To help alleviate Eva’s anxiety, I placed the NMES on myself as well so we could do it together, while slowly increasing the intensity. I described the sensation of NMES as “little men that were working with her muscles to make them stronger.” I asked her to help the “little men” every time they came marching out of the pads by pushing her knee down.5
I was taught to call the process “preparing the neighborhood” by a former colleague, Scott Tennis, MS, PT, to make it seem less daunting to the children. This refers to stretching the surrounding muscles and joints, which increases the effectiveness and range achieved with knee flexion stretching in sitting and prone.
The key to effective maintenance of increasing the range of motion is strengthening the opposing musculature. Patellar mobilization along with hip abductor/adductor stretches, hamstring stretches in supine, Thomas hip flexion stretch and ankle stretching with the knee extended is performed. The knee flexion stretches were done when I felt that the muscles were adequately prepared.
An inferior glide to patella with knee flexion stretches decreases the patient’s pain, improving the patellar femoral motion and therefore often increasing the range achieved.
Dynamic exercises including ambulation training on a pediatric treadmill and ambulating through an obstacle course challenged Eva’s balance, improved her functional mobility and decreased her risk of falls. Aquatic therapy aided in strengthening and helped Eva avoid undue stress on the bone and joint.
The consolidation phase begins once lengthening is completed and the desired length is achieved. The external fixator remains on to support the weakened bone and stays throughout the entire consolidation phase.
In the consolidation phase, therapy continues to address ROM; however, now gains may be achieved. Therapy is no longer working against continual bone and limb lengthening. Strengthening exercises with resistance are incorporated into the treatment and goals. When the external fixator is removed, PT is stopped for about six weeks to avoid a fracture through the pin hole or regenerated bone.
The process can be difficult and painful for a child, and seeing the pain that is generated through the required therapy can be upsetting for the therapist. PTs should make sure their patients understand they are trying to help them. Despite the difficulty of the therapy, Eva still gave me a hug goodbye at the end of each day. That gesture got me through the most difficult sessions with her, and allowed me to push her just as hard the next day.
Patients and their families travel from all over the country and world to receive the specialized care provided by Dror Paley, MD, and his team at the Paley Advanced Limb Lengthening Institute in West Palm Beach, FL.
Working with Dr. Paley, his team and patients like Eva is a privilege and a life-altering experience. As the patients’ lives are forever changed due to the lengthening process, so is mine as the therapist. Eva is currently in the consolidation phase and receiving therapy in her hometown.
References are available at www.advanceweb.com/pt or by request.
Emily Rade is a senior PT for the Paley Advanced Limb Lengthening Institute Rehabilitation Department of St. Mary’s Hospital in West Palm Beach, FL, specializing in orthopedics, women’s health, lymphedema and balance and vestibular disorders.