Femoral anteversion (FA) is a structural condition defined by an inward, or forward, twist in the femur, which is the long bone of the thigh. This bony twist causes the entire leg to rotate internally, resulting in the characteristic in-toeing gait often described as “pigeon-toed” walking. While this alignment variation is common in children and usually corrects naturally with growth, persistent or severe femoral anteversion in adults represents a fixed skeletal deformity. Adult patients often seek treatment due to chronic issues like hip pain, patellofemoral maltracking leading to knee pain, joint instability, or an elevated risk of developing hip osteoarthritis from abnormal joint loading. The permanent nature of the adult skeletal structure means that resolving this mechanical issue requires a specialized orthopedic approach to physically correct the bone’s orientation.
Confirming the Diagnosis and Severity
The process of confirming femoral anteversion begins with a detailed physical examination performed by an orthopedic specialist. A key finding is a notable imbalance in hip rotation, specifically an excessive amount of internal rotation accompanied by a corresponding decrease in external rotation. This clinical finding provides a strong initial indication of a torsional deformity in the femur.
To accurately diagnose and quantify the severity of the twist, advanced imaging is required because physical examination alone cannot precisely measure the bony angle. Computed Tomography (CT) scans are traditionally considered the gold standard for this assessment, though Magnetic Resonance Imaging (MRI) is also utilized for its ability to measure the exact angle of torsion without ionizing radiation. These scans measure the femoral anteversion angle, which is the angle between the axis of the femoral neck and the transcondylar axis of the knee.
The normal adult anteversion angle is generally accepted to be between 10 and 15 degrees. Intervention is typically considered only when the angle is pathologically high and correlates directly with the patient’s symptoms, often exceeding 20 to 30 degrees. Precise measurement of this angle dictates the exact degree of correction required for any potential surgical procedure.
Non-Surgical Management Strategies
Non-surgical approaches are primarily focused on managing the symptoms associated with femoral anteversion, rather than structurally correcting the underlying bony twist. These conservative methods are used because the adult skeleton is skeletally mature, meaning the bone structure is fixed and will not remodel itself over time. Consequently, non-operative treatments cannot alter the excessive forward rotation of the femur.
Physical therapy (PT) constitutes a main component of non-surgical management, aiming to improve hip stability and gait mechanics. A specific focus is placed on strengthening the hip’s external rotator muscles, particularly the gluteus medius, which can help compensate for the internal rotation. Strengthening these muscles helps to better center the femoral head within the hip socket, potentially reducing abnormal joint strain.
Patients may also find symptomatic relief through the use of shoe inserts or specialized orthotics designed to optimize foot and ankle alignment. While these devices can reduce discomfort in the lower leg and improve the foot’s position during walking, they have no effect on the angular twist within the femur itself. Non-surgical management is typically a long-term strategy for symptom control, reserved for patients with mild to moderate symptoms who do not meet the criteria for surgical correction.
Definitive Surgical Correction
For adult patients with severe, symptomatic femoral anteversion that has failed to respond to conservative management, the definitive treatment is a procedure called a Derotational Osteotomy (D.O.). This major orthopedic surgery is designed to physically correct the abnormal rotational alignment of the femur. The goal of the procedure is to realign the bone to reduce in-toeing, normalize the gait pattern, and decrease the pathological strain on the hip and knee joints.
During the Derotational Osteotomy, the surgeon makes a calculated cut, or osteotomy, into the femur, often in the subtrochanteric region near the hip or in the shaft of the bone. The bone segment is then carefully rotated outward by the exact number of degrees determined during the pre-operative CT or MRI planning. This rotation repositions the femoral head and neck relative to the knee joint, restoring a more normal anteversion angle.
Once the bone is rotated to the ideal alignment, it must be rigidly held in place to allow for bone healing. This fixation is achieved using internal hardware, typically a strong plate with screws or a long intramedullary nail inserted down the center of the bone. The use of an intramedullary nail provides robust stability and is a common technique for this type of long-bone surgery.
While highly effective at correcting the skeletal deformity, the procedure carries risks common to major orthopedic operations:
- Potential for surgical site infection
- Nerve or blood vessel damage
- Risk of non-union (failure of the bone fragments to successfully heal together)
The hardware used for fixation is often large and may become symptomatic over time, frequently necessitating a second surgery for its removal after the bone is fully healed.
Post-Intervention Rehabilitation
Following a Derotational Osteotomy, the post-intervention rehabilitation phase is extensive and critical for a successful outcome. Immediately after the procedure, pain management is a primary focus, and patients are typically placed on a period of limited or non-weight bearing on the operated leg. This restriction is crucial to protect the osteotomy site while the bone fragments begin to fuse.
The process of bony healing often requires six to twelve weeks before the patient is cleared to progress to full weight-bearing. Intensive physical therapy begins during this phase, initially focusing on maintaining range of motion in the hip and knee without stressing the surgical site. The long-term rehabilitation goal is to rebuild muscle strength lost due to the surgery and the period of disuse.
Therapy focuses on strengthening the major muscle groups of the leg, especially the quadriceps and gluteal muscles. The body must adopt the new, corrected gait pattern, which can take several months. Most patients can expect a gradual return to unrestricted daily and sports activities, which commonly occurs between six and eight months after the operation.