What are the implications of a leg length discrepancy (LLD)?

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Last updated: April 15, 2025View editorial policy

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From the Guidelines

Leg length discrepancy should be managed based on the severity of the discrepancy, with treatment options ranging from simple shoe lifts to surgical intervention, and regular monitoring is essential to address any changes in the discrepancy over time, as evidenced by recent studies 1.

Treatment Options

  • For minor differences (less than 2 cm), no treatment may be necessary or simple shoe lifts can be used to equalize leg lengths.
  • For moderate discrepancies (2-5 cm), custom shoe lifts or orthotic devices are typically recommended.
  • Severe discrepancies (greater than 5 cm) may require surgical intervention, such as limb lengthening procedures or epiphysiodesis (growth plate fusion) in growing children.

Importance of Monitoring

Regular monitoring is essential, especially in growing children, as the discrepancy may change over time, and underlying causes such as congenital conditions, fractures, infections, or neurological disorders should be identified and addressed.

Surgical Intervention

Surgical intervention, such as osteotomies or guided growth techniques, may be necessary to correct deformities and improve functional outcomes, as recommended in recent studies 1.

Physical Therapy

Physical therapy is often beneficial to address any gait abnormalities or muscle imbalances resulting from the discrepancy, and can help improve functional outcomes and reduce the risk of complications.

Recent Evidence

Recent studies, such as those published in 2019 1 and 2025 1, provide guidance on the management of leg length discrepancy, including the use of surgical intervention and physical therapy to improve functional outcomes and reduce the risk of complications.

From the Research

Definition and Causes of Leg Length Discrepancy

  • Leg length discrepancy (LLD) occurs when the paired lower extremities are unequal in length, with effects varying depending on the cause and size of the discrepancy 2.
  • LLD can be etiologically classified as functional or structural, with length differences typically less than 10 mm and asymptomatic or easily compensated for by the patient through self-lengthening or shortening of the lower extremities 2.

Diagnosis and Assessment of Leg Length Discrepancy

  • LLD can be assessed directly through tape measurements or indirectly through palpation of bony landmarks, with imaging modalities such as radiography providing more precise measurements and helping to identify coexistent deformity 2.
  • Discrepancies greater than 20 mm can alter biomechanics and loading patterns, resulting in functional limitations and musculoskeletal disorders, such as functional scoliosis 2.

Treatment Options for Leg Length Discrepancy

  • Treatment options for LLD include conservative methods such as shoe inserts, high shoes, or orthoses, as well as surgical methods such as limb shortening or lengthening 3, 4, 5.
  • Limb shortening is an option to manage LLD, with procedures such as epiphyseodesis, stapling, or shortening osteotomy available for skeletally mature or immature patients 4, 5.
  • Lengthening procedures, such as osteotomy and subsequent distraction of the bone callus, can also be used to correct LLD, with predictive algorithms available to estimate the final extent of the discrepancy 3.

Complications and Long-Term Effects of Leg Length Discrepancy

  • Long-standing LLD and functional scoliosis can result in permanent degenerative changes in the facet joints and intervertebral discs of the spine 2.
  • Discrepancies greater than 5 cm may require initial leg-lengthening treatment during the patient's growing years, with the decision to treat always being elective and dependent on individual patient factors 3.
  • The extent of the discrepancy is not the sole determining factor for the mode of treatment, with changes in leg length exerting marked mechanical stress on the soft tissues 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Leg Length Discrepancy- Treatment Indications and Strategies.

Deutsches Arzteblatt international, 2020

Research

Limb shortening for the management of leg length discrepancy.

Journal of the Royal College of Surgeons of Edinburgh, 1999

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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