Leg Length Discrepancy

Leg Length Discrepancy is a condition where the length of one leg is different than the other (shorter or longer) because of either or both a functional (muscle/posture) or structural (bone/cartilage) abnormality.

Aetiology

Idiopathic

Dysgenesis
  1. Abnormal development during embryonic growth.
  2. Failure of the normal development during childhood or adolescence.

Trauma & Medical Causes

Trauma
  1. Fracture – poor healing or improper setting
  2. Epiphyseal injury
Medical Induced (Iatrogenic)
  1. Hip or knee prosthesis (joint replacement)
  2. Amputation, knee menisectomy
  3. Immobilisation during growth period
  4. Radiation therapy

Disease

Hip disorders
  1. Sacroiliac Joint Dysfunction, Dysplasia
  2. Legg-Calve-Perthes
  3. Slipped Capital Femoral Epiphysis (SCFE)
  4. Marked hip or knee degenerative arthritis
Neuromuscular
  1. Muscle imbalance causing different pull on pelvis
  2. Cerebral Palsy, Polio
Other Causes
  1. Neoplasm (fibrous dysplasia, neurofibromatosis)
  2. Infection

History, Signs & Symptoms

Presentation

  1. Patients with leg length discrepancy may present with an altered gait (limp) and/or lumbar scoliosis & lower back pain
  2. Possible spinal anatomical changes for long-standing conditions
    1. Vertebral body wedging, increased spurring
    2. Increased disc degeneration
  3. Possible associated lower extremity disorders
    1. Increased hip pain & degeneration (long leg)
    2. Increased risk of:
      • Knee pain/injury, ITB Syndrome
      • Pronation syndromes & plantar fascitis

Physical Exam & Investigations

General Exam

  1. Asymmetrical strength in lower extremity
  2. Asymmetrical range of motion

Orthopaedics Exam

  1. (+) Allis Sign
  2. Standing iliac crest height difference
  3. Prone or supine leg length difference
  4. Leg length measurements

Imaging – (X-Ray)

To determine the extent of the leg length discrepancy or to confirm it, the following imaging would be taken:

  1. Three exposures to a full spine film (divided into 3 sections) of a weight-bearing patient
  2. Looking for height & length differences between:
    • Femoral heads
    • Knee joints
    • Ankle joints

Management

Physical Treatment

  1. With leg length discrepancy it is important to improve the function of the entire spinal & pelvis, using osseous manipulations, mobilisation techniques, as well as rehabilitative exercises.
  2. Massage therapy & stretching of tight shortened musculature
  3. Heal Lift will help by:
    • Reduce low back pain caused by leg length discrepancy
    • Reduce spinal scoliosis, lordosis and/or kyphosis
    • Normalize lower extremity biomechanics weight distribution

Heel Lift Application

  1. Discrepancies greater than 6-10 mm may require a heel lift
  2. Pelvic & spinal manipulation prior & during lift therapy will enhance effect by minimising functional causes
  3. Heel lift height should be built up gradually to allow body time to adapt to changes
  4. Height of heel lift should be determined by:
    • Age of patient: younger patients will tolerate greater corrections than older patients
    • Severity of scoliotic curve: more severe curves may require more gradual therapy
    • Tibia vs. femur shortening: tibia often requires a higher percentage correction than femur (attempt to minimize abnormal knee biomechanics)
    • Activity of the patient: more active patients may require a more precise & dynamic lift