Leg Length Discrepancy (LLD) is a condition where the two lower limbs are unequal in length. This difference is categorized as either structural or functional. A structural LLD involves an actual difference in the bone lengths of the femur or tibia, often due to congenital conditions, trauma, or disease. Conversely, a functional LLD occurs when bone lengths are equal, but muscular imbalances, pelvic tilt, or spinal misalignment create the appearance of a discrepancy. The appropriate medical path depends entirely on the nature of the LLD.
Initial Diagnosis and Primary Care Screening
The first step in addressing a suspected LLD is typically a visit to a Primary Care Physician (PCP) or a pediatrician, who acts as the initial gatekeeper for specialized care. This doctor performs a thorough physical examination, observing the patient’s posture and gait, and looking for signs such as a noticeable limp, uneven shoulder heights, or a pelvic tilt. A common screening method involves placing measured wooden blocks under the shorter leg until the patient’s hips appear level, which helps estimate the approximate discrepancy. If the doctor suspects a true, structural LLD, the next step is ordering diagnostic imaging, often an X-ray or a specialized full-length standing radiograph to confirm the bone length difference.
Specialists for Non-Surgical Management
For most cases, especially structural discrepancies under 2 centimeters or functional discrepancies, non-surgical intervention is the primary course of action. This management involves a team of allied health professionals focusing on restoring balance, function, and comfort.
Physical Therapists (PTs)
Physical Therapists (PTs) are particularly helpful in managing functional LLD, which often stems from muscle tightness or weakness around the hips and pelvis. A PT utilizes manual therapy to mobilize restricted joints and employs targeted exercises to correct muscle imbalances, such as strengthening the glutes and abdominals or stretching tight hip flexors. They also provide specific gait training to retrain walking patterns and reduce the compensatory mechanisms that lead to pain.
Podiatrists and Orthotists
Podiatrists and Orthotists specialize in the prescription and fitting of shoe lifts and custom orthotics. For structural LLD, a custom orthotic with a heel lift or a full sole lift is often recommended to physically compensate for the difference in bone length. They design the insert to improve foot alignment, redistribute weight, and reduce strain on the knee, hip, and back joints.
Chiropractors
Chiropractors address LLD primarily when it is functional, focusing on misalignments of the spine and pelvis. They use specific adjustments to realign the pelvis, which may have rotated or tilted, creating the appearance of a shorter leg. By restoring proper joint mechanics, chiropractic care aims to alleviate the compensatory strain that causes symptoms like lower back pain.
Surgical and Complex Care (The Orthopedic Specialist)
An Orthopedic Specialist, particularly one with experience in limb reconstruction, becomes the primary doctor when LLD is complex, severe, or requires surgical correction, generally recommended for structural discrepancies predicted to exceed 2 centimeters, or those caused by congenital issues, severe trauma, or growth plate disturbances. The orthopedic surgeon uses advanced diagnostic tools like a computed tomography (CT) scanogram, which provides highly accurate measurements of the bone segments in both limbs.
Children’s Care
In children, the orthopedic specialist is responsible for long-term monitoring and uses specialized growth charts to predict the final discrepancy at skeletal maturity. For a child with significant remaining growth, one surgical option is epiphysiodesis, a procedure that slows or temporarily stops the growth of the longer limb to allow the shorter limb to catch up. This is typically reserved for discrepancies up to about 5 centimeters and must be timed precisely.
Adult Care
For adult patients or those with very large discrepancies, the surgeon may recommend limb lengthening procedures. This complex process involves cutting the bone and using an internal or external device to gradually separate the bone segments, stimulating new bone growth. Alternatively, for skeletally mature patients with discrepancies up to 5 centimeters, the surgeon may perform a limb shortening procedure on the longer leg by removing a segment of bone.