Limb-length discrepancy can be caused by structural, functional, or environmental factors that result in one leg being longer or shorter than the other. Symptoms of discrepancy include an awkward gait, back pain, and compensatory scoliosis. Discrepancies are classified as mild (<3cm), moderate (3-6cm), or severe (>6cm). Treatment depends on the magnitude of discrepancy and may include shoe lifts for mild cases, growth modulation for moderate, and limb lengthening or shortening surgery for severe discrepancies. The goal of treatment is to alleviate symptoms and prevent long-term complications.

1. Limb-Length Discrepancy
evaluation
Prepared by:
Dr. Abdullah K. Ghafour
2nd year IBFMS trainee
Supervised by:
Dr. Ali Abdulnabi Alwan

2. Definition and epidemiology:
• Differences between the lengths of the upper and/or lower arms
and the upper and/or lower legs.
• Except in extreme cases, arm length differences cause little
or no problem in how the arms function.
• the majority of individuals (up to two thirds ) have some
degree of limb inequality .
• The average discrepancy less than 1.1 cm can easily compensate.

3. Symptoms :
• The short leg gait is awkward
• increases energy expenditure because of the
excessive vertical rise and fall of the pelvis
• back pain from long-standing significant discrepancies.
• Compensatory scoliosis and decreased spinal mobility.

4. Types of LLD:
I. Structural or Anatomic type: due to a difference
in the actual length of the tibia or femur.
• Congenital
– Hemihypertrophy
– Dysplasias
– PFFD
– DDH
– unilateral club foot
• post-trauma
• post-surgery
proximal femoral focal deficiency
unilateral club foot

5. Types of LLD:
II. Functional type: is due to asymmetrical foot or limb function .
• hip flexion or adduction contractures
• flexion or hyperextension deformities of the knee
or ankle
• pelvic obliquity
• genu varum and genu valgum

6. Types of LLD:
III. Environmental type: is caused by the unevenness created by walking or
running on crowned road surfaces, banked running tracks or along the beach.
Another Classification is McCaw and Bates (1991):
o LLD has been classified according to the magnitude of the inequality,
generally expressed in cm or mm, and described as ;
 Mild Less than 3 cm
 Moderate 3-6 cm
 Severe More than 6 cm

7. Etiology of Undergrowth
• Congenital limb deficiency :
– Congenital femoral deficiency,
– congenital fibular deficiency,
– tibial hemimelia
• Asymmetrical neurological disorders:
– Hemiplegic CP
– poliomyelitis
– Hemimyelomeningocele
• Traumatic causes:
– malunion
– growth plate arrest

8. Etiology of Undergrowth
• Hemiatrophy:
- Idiopathic
- Russel-Silver syndrome.
• Other causes:
– infection, tumor
– post-irradiation
– Blount’s disease
– LCPD
– unilateral clubfoot
– congenital pseudarthrosis of the tibia

9. Etiology of Overgrowth
• Post-traumatic overgrowth:
– femur shaft fracture
– tibia shaft fracture
• Soft tissue overgrowth syndrome:
– Gigantism with neurofibromatosis
– Klippel-Treunaunay syndrome
– Beckwith-Wiedemann syndrome
– Proteus syndrome
• Chronic inflammatory arthritis
– Rheumatoid Arthritis
• Idiopathic hemihypertrophy.

10. Clinical assessment
• History:
– Congenital or acquired?
– Trauma / infection?
– Progressive / static?
– Onset and mode of deformity?
– Any Syndrome associated features?

11. Clinical assessment
• Examination:
– Gait
– Lower limb;
o Determine which segment is short?
o Is it too long or too short?
o Foot exam
o Exclude fixed deformities(knee and foot)
o Muscle wasting?
– Spine;
o Scoliosis (fixed or mobile)?
– Upper limb
– face

12. Clinical assessment
• Examination:
– Wood block test
• Check the knee fully extended
• ASIS level and Check spine
• block testing is considered the best initial screening method
– Galeazzi (Allis) test

13. Clinical assessment
• Examination:
– tape measurement
• measure from the ASIS to the medial malleolus (true
length)
• measure from the umbilicus to
the medial malleolus (apparent
length)

14. Investigations
• Standing radiographs
• Teleroentgenogram
• Orthoroentgenogram
• CT–scannogram

15. Investigations
• Standing radiographs
o Block up shorter leg

16. Investigations
• Teleroentgenogram:
o Single exposure and single cassette
o Disadvantage: magnification error
Length of x-ray shadow

17. Investigations
• Orthoroentgenogram:
o single cassette is used
o 3 exposure center (hip, knee and ankle)
o Disadvantage: only see the joint

18. Investigations
• CT–scannogram
o most accurate diagnostic test with contractures

19. Investigations : Skeletal Age
1. Greulich- Pyle Atlas
– X-ray Left hand (non dominant)
– correlated with Green- Anderson table
– less accurate < 6 Y
– improved accuracy by focusing on hand bones
rather than carpal bones
2. Tanner- Whitehouse Atlas
– more refined
– 20 landmarks graded Lt Hand
– more accurate

20. Prediction Methods in LLD
I. Rule of thumb Westh and Menelaus (1981)
o Main use is to time growth arrest
II. Growth remaining Anderson and Green (1963)
o Determine the length of the long leg at maturity
o Calculate the future growth of the long leg
o Calculate % inhibition of shorter leg
o Calculate the future increase in discrepancy
III. Straight line Moseley (1978)
o Graphical representation of Green and Anderson method
IV. Paley Multiplier Method (2000)
o take LLD for boy or girl
o multiplier for chronological or skeletal age
o predicts LLD at maturity

21. Guidelines for Management
Discrepancy Management
(CM)
<2 No treatment or shoe lift
2-5 Growth Modulation
5-12.5 Consider bone-lengthening
>12.5 Combinations of above or
amputation

22. Management of LLD:
• Shoe lift:
o Patient who do not wish or are not appropriate for surgery.
o Lift higher than 5 cm poorly tolerated.
o Not good for bare foot

23. Management of LLD:
• Growth Modulation:
• Epiphysiodesis: (kill the growth plate)
• Very low morbidity and complication rate.
• Slowing growth rate of long leg and allowing short
leg to catch up
• Suitable for sufficient data to enable a confident
prediction of discrepancy at maturity.
• Eight Plates (squeeze the growth plate)

24. Management of LLD:
• Shortening operation:
o Mature patient
o Tibia< 4cm, Femur< 5cm
o Neurovascular complication is higher in tibia,
fasciotomy is advisable.

25. Management of LLD:
• Limb lengthening operation:
o used to replace missing bones and/or to straighten deformed
bones.
o Can be performed on both children and adults with limb length
discrepancies (< 6cms) and angular deformities due to birth
defects, injuries or diseases.
o Device for gradual lengthening
 Unilateral fixator
 Circular ring fixator (Ilizarov, Taylor spatial frame )
o Combined internal and external fixation
 (Lengthening over IM Nailing)
o totally implantable lengthening device
 Albizzia nail
 ISKD(inter medullary skeletal kinetic device)
 Fitbone

26. Management of LLD:
• Prosthetic fitting:
Significant discrepancies:
o deformed functionally
o useless feet
o discrepancies greater than 15-20cm
o femoral length less than 50%
o Fibular hemimelia with unstable ankle
o PFFD
A/K prosthesis or BK prosthesis with Van –Nes
rotation plasty

27. Management of LLD:
• Amputation:
o Significant length discrepancy
o Severe fixed deformities
o Poor underlying bone quality for lengthening
o Dysfunctional/ painful limb
Klippel Tenaunay Syndrome

28. References:
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20th ed. by Elsevier, Inc. Canada.
• Albert J. Pomeranz, Svapna Sabnis, [2016] PEDIATRIC DECISION-MAKING
STRATEGIES, SECOND EDITION, 2nd ed. An Imprint of Elsevier , Tennessee, USA.
• Solomon L., Warwick D. , Nayagam S.,[2010] Apley’s System of Orthopaedics and
Fractures, 9th ed. Hodderarnold comp.,London, UK.
• Miller M. , Thompson S. , Hart J. ,[2012] REVIEW OF ORTHOPAEDICS [PDF], 6th
ed. by Saunders, an imprint of Elsevier Inc. , Philadelphia, USA.
• Canale S. , Beaty J. , [2007] Campbell’s Operative Orthopaedics [PDF], 11th ed. By
Mosby, An Imprint of Elsevier , Tennessee, USA.
• Jay R. Lieberman, MD. , [2009] AAOS Comprehensive Orthopaedic Review,2nd ed.
American Academy of Orthopaedic Surgeons, USA.
• L. Ombregt, [2013] A System of Orthopaedic Medicine, 3rd ed. Elsevier Ltd. China.