Limb length discrepancy

1. LIMB LENGTH DISCREPANCY
Dr. Sudarshan Pandey
Resident
Department of Orthopedics and Traumatology
KUSMS

2. Anatomy
• Bone growth begins during embryological development
• Bone growth in length – Interstitial growth
• Bone growth in diameter- appositional growth

3. Anatomy

5. Definition
• Limb length discrepancy or anisomelia, is defined as a condition
in which the paired lower extremity have a noticeably unequal
length.
• commonly identified incidentally

6. • Congenital limb deficiency
• Congenital femoral deficiency
• Congenital fibular deficiency
• Tibial hemimelia
• Asymmetric neurologic disorders
• Hemimyelomeningocele
• Poliomyelitis
• Asymmetric static encephalopathy
(e.g., hemiparesis)
• Asymmetric peripheral neuropathy
Etiology: Causes for shortening of limb
• Trauma
• Malunion
• Physeal growth disturbance
or arrest after fracture

7. Acquired causes of physeal growth disturbance
• Infection
• Tumor
• Enchondroma
• Osteochondroma
• unicameral bone cyst
• Irradiation
• Infantile Blount's disease
• Adolescent Blount's disease
• Legg-Calvé-Perthes disease
• Hemiatrophy
• Idiopathic, nonsyndromic hemiatrophy
• Russell-Silver syndrome
• Unilateral clubfoot deformity
• Congenital pseudarthrosis of the tibia
Russel Silver Syndrome

8. Etiology: Causes of increased limb length
• Post-traumatic overgrowth
• Femoral shaft fracture
• Tibial shaft fracture
• Soft tissue overgrowth syndromes
• Gigantism with neurofibromatosis
• Klippel-Trénaunay syndrome
• Beckwith-Wiedemann syndrome
• Proteus syndrome
• Idiopathic hemihypertrophy
• Inflammatory arthritis

9. Proteus syndrome Idiopathic hemihypertrophy

10. Types:
LLD
STRUCTURAL FUNCTIONAL
Ireland and Kessel estimated that a functional discrepancy of 3 cm was created
with each 10-degree increment in hip adduction or abduction deformity, up to 40
degrees

12. Classification:
• McCaw and Bates (1991) report the following classification:
according to the magnitude of the inequality
• Mild Less than 3 cm
• Moderate 3-6 cm
• Severe More than 6 cm

13. Assessment of Inequality
• History
• Clinical findings
• Wood Block Test (Coleman’s Test)
• Using tape measures
• Galeazzi’s sign
• Thigh Leg technique
• Impact of LLD and Compensatory mechanism
• Imaging/ Radiograph

14. Assessment of Inequality
Clinical: History and Examination
• How long ?
• functional limitations in either limb?
• family history of skeletal dysplasia
• history of fracture, infection, or other significant injury to either
extremity.
• Significant malformations - congenital clubfoot deformity, skin
discoloration, or soft tissue enlargement

15. Clinical assessment
• Wood block test(coleman’s):
–patient standing, add blocks under the
short leg until the pelvis is level,
–measure the blocks to determine the
discrepancy.
–block testing is considered the best
initial screening method.

16. Assessment of functional and actual leg length
inequality on the examining table using a tape
measure
• umbilicus to the medial
malleolus (functional or
apparent discrepancy)
• anterior superior iliac
spine to the medial
malleolus (actual, true, or
structural discrepancy).

17. Galeazzi sign:
• Knee flexion
• Feet touches surface
• Ankle touches buttock
• If knees are not in level
• Apparent LLD
• (DDH/Short femur)

18. Thigh-leg technique of estimating leg length
inequality
• patient - supine with the hips
and knees flexed 90 degrees.
• Discrepancy noted between
the table and thigh
thighs and knees
soles with the knees even.
• Smith - clinical method
significantly superior to tape
measurement and slightly more
accurate than block
measurement.

19. Impact of Inequality
• development of scoliosis
• low-back pain
• sciatica
• excessive stress on hip or knee joints
• lower extremity dysfunction such as stress fracture, plantar fasciitis, or
parapatellar knee pain.
Liu and colleagues- discrepancies less than 2.3 cm resulted in
“acceptable” gait asymmetry
Discrepancies of less than 3% were not associated with compensatory
mechanisms

20. Compensatory mechanism
• Circumduction
• Persistent flexion of longer limb
• Vaulting over longer limb
• Toe walking on shorter limb
• when discrepancies exceeded 5.5%—could not
be compensated by toe-walking.
• More mechanical work by longer leg

21. ),
Compensation:
• Shoulder tilt
• Unequal arm swing
• Pelvic tilt
• Scoliosis towards same side,
• On longer side( Knee flexion and pronation
of ankle)
• On shorter side(Plantar flexion and
supination of ankle).

22. Clinical significance:
• Gait disturbance,
• Increased energy expense,
• Scoliosis and low backache,
• Equinus contracture of ankle,
• Late degenerative arthritis of
hip and knee,
• Callosities of foot.

23. Radiographs (Measure Length Discrepancy)
• Teloroentgenogram
• Orthoroentgenogram
• Scanogram (x-ray/ CT)

24. Teloroentgenogram
• An X-ray taken at a distance of
six feet and production of
shadows of natural size.
• A long film and a ruler are
placed under
the patient, and a single
exposure is made
centered over the limbs
• magnification error

25. Orthoroentgenogram
• A long film and a ruler are
placed under the patient. Three
(or six) exposures are made at
the hip, knee, and ankle level,
without moving the patient or the
film
• minimize measurement error due
to magnification by making three
separate exposures of the lower
extremities centered over the
hips, knees, and ankles.

26. Orthoroentgenogram:

27. Scanography
• similar to orthoroentgenography.
• It differs in that in addition to the
radiographic tube's being moved
over the patient for three
exposures, the film is moved under
the patient
• reduces the size of the film
required, making storage and
handling easier
• The entire length of the bone is not
available on film

28. Computed Tomography
• greater accuracy
• less susceptibility to error if the
patient is poorly positioned, and the
ability to accommodate positioning
difficulties secondary to joint
contractures or the presence of
external fixators

29. MANAGEMENT:
Depends on skeletal maturity
In children we should have ideas regarding
• Normal growth,
• Techniques for predicting growth and
• Appropriate time for intervention.

30. Prediction of Leg Length Inequality in the
Skeletally Immature Child

33. Techniques for predicting growth:
• Green and anderson method,
• Moseley’s chart,
• Menelaus method
• Paley’s multiplier method.

34. Menelaus method :
Relies on chronological age rather than skeletal age
• Proximal Femur
– 3mm / year
– 15% leg
• Distal Femur
– 9mm / year
– 37% leg
– 70% of femur
• Growth Cessation
– 14 Girls
• – 16 Boys
• Proximal Tibia
– 6mm / year
– 28%
– 60% tibia
• Distal Tibia
– 3mm / year
• – 20%

35. Green and anderson method:
• Growth remaining method
–uses skeletal age
–requires graph
–estimates growth potential in distal femur and proximal
tibia at various skeletal ages
• Green and Anderson growth data whereby the lower extremities
grow after the age of 5 years an average of 3.5 cm per year (2 cm/yr
from the femur and 1.5 cm/yr from the tibia) until puberty.

37. Moseley chart:
• Straight - Line Graph Method
– uses Green & Anderson data
– applied to a chart
• At least 3 measurements each time
1. Length long leg
2. Length short leg
3. Skeletal age
• Do so 3 times separated by 3-6 months
accuracy improves with increased plotting

38. Moseley chart:
Anticepated discrepancy
At maturity

41. Paley multiplier:
• Congenital Limb Length Discrepancy
• ∆m = ∆ x M
– ∆m: Limb discrepancy at skeletal
maturity
– ∆: Current Limb-length
discrepancy
– M: Multiplier.
• Example:current LLD is 4cm in
Congenital hemihypertrophy of 10 yrs
boy
• Using value of 1.310 according to
Multiplier chart at age of 10 in tibia
• 4 x 1.310 = 5.24 cm(LLD at maturity)

42. Summary of Prediction Methods
Shapiro - not all growth inhibition in growing
children is linear.
post–femoral shaft
fracture overgrowth.
such as septic arthritis, Legg-Perthes disease, and avascular necrosis (AVN)
associated with the treatment of developmental dysplasia of the hip

43. • In Shapiro’s type 1 : proximal femoral focal deficiency, Ollier disease
(enchondromatosis), congenital femoral deficiency with >6 cm of
shortening, physeal obliteration from any cause, and poliomyelitis.
• In Shapiro’s type 2 :congenital femoral deficiency <6 cm of shortening or
with poliomyelitis.
• Idiopathic hemihypertrophy or hemiatrophy demonstrated type 1, 2, or 3
patterns. Only 31% of patients with overgrowth associated with vascular
anomalies had type 1 growth, and the remainder had a type 2 or 3 pattern.
Patients with neurofibromatosis most commonly had a type 1 pattern, but
types 2, 3, and 5 were also seen. Similarly, patients with juvenile arthritis
exhibited types 1, 2, 3, and 5 patterns.
• Patients with Legg-Perthes disease exhibited all five patterns.

44. Management
• Goal
• Balanced spine and Pelvis
• Equal limb length
• Correct mechanical weight bearing axis
• Limb length equalization
1. Shoe lift or prosthetic conversion
2. Epiphysiodesis of long leg
3. Shortening of long leg
4. Lengthening of short leg

45. Treatment of Leg Length Inequality

47. Orthotic Management
Shoe Lift :
• Short term indication
• When child begins to toe walk i.e, when
LLD= 5%
• up to 1 cm can be incorporated into most
shoes
• Lifts > 8 cm are not easy and may cause
them to fall over or sprain their ankles
Ankle Foot Orthosis:
• (usually set in equinus, with an anterior
shell or, more commonly, a knee-ankle-
foot orthosis) and a shank terminating in
a solid ankle-cushioned heel prosthetic
foot
• LLD>5-10cm

48. Operative management:
Shortening of Long Leg
• Epiphysiodesis
• Percutaneous Physeal excision
• Epiphyseal stapling
• Transphyseal Screws
• Acute shortening
• Femoral shortening
Lengthening of short leg
• Acute lengthening – Transiliac
(Millis and Hall) lengthening
• Gradual lengthening
• External fixator- Illizarov
• Distraction Epiphysiolysis
• Intramedullary legthening devices
• PRECISE NAIL
• ISKD
• Fitbone

49. Epiphysiodesis:
• Procedure which arrest growth of that particular physis
• Slowing growth rate of long leg and allowing short leg to catch
up.
• Indications:
• Sufficient growth left for correction,
• Patient growing at or above 50th centile and will be taller
than average height,
• Discrepancy of 2 – 5 cm.

50. Disadvantages:
• Normal limb is operated on, instead of pathologic limb,
• Any deformity in pathologic limb cannot be corrected by this
method,
• The final height at maturity may be unacceptably low,
• Body proportions may be cosmetically displeasing.

51. Techniques:
• Phemister epiphysiodesis (1933),
• Blount’s epiphysiodesis (1949),
• Percutaneous epiphysiodesis by CANALE ETAL,
• Percutaneous trans-epiphyseal screw epiphysiodesis by
METAIZEAU ET AL,
• Tension plate epiphysiodesis.

52. Phemister technique:
To stop the growth with open
destruction of physis at correct
time to achieve equal limbs.
Proximal fibular
epiphysiodesis is done if >2cm
of tibial correction needed.
3x1-1.5x1cm

53. Percutaneous Epiphysiodesis

54. Percutaneous epiphysiodesis:
Area of plate to be removed
in epiphysiodesis.
Obliteration of medial and
lateral circular segments of
the plate, leaving the central
part and the strong periphery,
successfully stops growth, yet
the bone retains sufficient
strength to forego
immobilization.

55. Percutaneous epiphysiodesis using
transphyseal screw (PETS) :
Metaizeau technique

56. Epiphyseal Stapling
Ideal spacing of staples, as recommended
by Blount.Three evenly spaced staples
should be placed extraperiosteally, with
their tines parallel to the physis
Angular correction-
Hemiphysiodesis

57. TENSION PLATE EPIPHYSIODESIS
• Reserved for hemiepiphysiodesis
• can be ued for complete
epiphysiodesis if implants are
used on both sides of the
physis.
• advantage of potential growth
resumption with implant
removal; however, restoration of
normal growth often is
unpredictable after implant
removal

58. Problems of Epiphysiodesis
• Under correction of growth or angulation
• Overcorrection growth or angulation
• Asymmetric growth arrest
• Nerve injury, infection
• Implant failures.

59. Limb Shortening operation:
• WAGNER outlined the approach to limb shortening,
• WINQUIST deviced closed technique for diaphyseal
shortening,
• INDICATIONS:
• Skeletally mature patient,
• Tibia 2-3cms, Femur 4-5cms can be removed without affecting
muscle function, (Discrepancy less than 5cms),
• Patient height more than 50th percentile.

60. • Wagner recommended metaphyseal osteotomy if angular or
rotational correction is required, and diaphyseal osteotomy if
shortening alone is necessary

61. Femoral shortening is tolerated
better than tibial shortening
Femoral shortening: Tibial shortening:
Upto 5 cm tolerable, Upto 3 cm tolerable
Only one bone is involved and is protected by
muscles around the thigh,
Has to deal with two bones,
Delayed and non union are less common, Chances of neurovascular bundle injury is
higher, (Fasciotomy is required)
Muscles regain strength and tension quickly. Recovery of muscle takes longer time.
• ,

62. Acute femoral shortening
Options for open acute femoral
shortening. A, Shortening in the
midshaft of the femur with
plating. B, Proximal femoral
shortening with a compression
screw plate or similar
fixation. C, Distal femoral
shortening with compression
plate fixation.

63. Shortening operation:

64. Tibial shortening:
Tibial shortening using step-cut and
screw fixation A, Longitudinal osteotomy
with step-cuts in the shaft of the
tibia. B, After shortening of the tibial shaft
and transverse screw fixation.
Open tibial shortening with intramedullary
rod fixation in the tibia. Wagner technique for proximal
tibial Metaphyseal shortening

65. Closed diaphyseal Shortening:
Closed femoral diaphyseal shortening, as described by Winquist et al. A, Medullary canal is reamed with
standard cannulated reamer. Special medullary saw is inserted into reamed canal. One or two rotations are made with saw at each
setting, and saw is progressively opened until blade is completely exposed. B, After both saw cuts have been made, intercalary
segment is split using back-cutting chisel. Rotational alignment and distraction can be controlled with locked medullary nail.

66. Limb lengthening operation:
Indications:
• Shortening >6 cms,
• nearing skeletal maturity where epiphyseal arrest or shortening of
bone of long limb would not produce satisfactory equalization,
• When discrepancy is more in a single bone due to trauma/ infection
Pre requisites:
• Neighbouring joints should be free with good ROM,
• Absence of scarring of skin or soft tissue,
• Bone should be normal,(Fracture if any should be united).

67. Limb lengthening operation:
The success depends on :
• patients and families commitment in maintaining external fixator
• Efforts in physiotheraphy
• Patience.

68. Limb lengthening:
• Not advisable in Patients who are unable to participate in
frequent follow-up or who do not have the support to care for
the fixator properly and to undergo vigorous physical therapy
are best treated by means other than lengthening,
Limb lengthening
Acute
Gradual

69. Acute lengthening:
• Cut the bone, spread the two sections apart, and insert a graft
and internal fixation is done to maintain the length.
• Surrounding muscles, nerves and blood vessels do not tolerate
a lot of stretching.
• Only limited increase is acheived. For example, forearm
bones (radius or ulna) and foot bones (metatarsals) are
lengthened by this method when only a small gain in length is
needed

70. One stage lengthening:
Transiliac: (MILLIS AND HALL)
• Average lengthening of 2.3 cm
Indication
• Acetabular dysplasia with femoral shortening
• Pure LLD
• Decompensated scoliosis
• Primary intrapelvic assymmetry

72. Gradual lengthening - Distraction
Osteogenesis:
• Principle:
1) Corticotomy: preserve endosteal & periosteal blood supply in
metaphyseal region,
2) Ilizarov Ring fixator or unilateral LRS
3) Latency period: 7-14 days
4) Proper rate & Rhythm: 0.25mm x4 / day
5) Encourage Joint motion

73. Limb lengthening operation:
• Devices for gradual lengthening
• External fixators:
• Unilateral fixator (Orthofix / LRS)
• Circular ring fixator (Ilizarov, Taylor spatial frame )
• Intramedullary lengthening device
• PRECISE – Approved in USA,
• ISKD(inter medullary skeletal kinetic device),
• Fitbone.

74. Distraction Epiphysiolysis
• Chondrodiastasis (Gelbke,1951, De Bastiani,1986)
• Separation of the epiphyseal plate
• Immature patient
• Risk of septic arthritis
• Painful stiffness of the joint
• Premature closure of the physis

75. Tibia Lengthening: Illizarov frame
(DEBASTIANI ET AL) Orthofix lengthening devices

76. Femur lengthening:
A, DeBastiani technique for corticotomy. Using limited open exposure and a 4 or 5 mm drill, multiple holes are drilled
in anterior half of bone. These are connected with 5-mm osteotome, which also is used to complete corticotomy posteriorly. B,
Orthofix device for femoral lengthening. To control varus deviation, three screws are used proximally and three distally, or frame
can be applied with prophylactic valgus built into construct

77. Femoral lengthening:

78. Complications:
• Muscle contractures
• Joint subluxations
• Neurological or vascular insult
• Premature or delayed consolidation
• Re- fracture
• Pin- site infections
• Psychological stress

79. Intramedullary lengthening devices:
Advantages:
• No pin tract infection and soft-tissue transfixation,
• To maintain mechanical alignment and stability during
lengthening and consolidation, and
• To improve patient comfort and tolerance.

80. Types of intramedullary devices:
• Lengthening may be initiated by
• controlled rotation, ambulation, and weight bearing
ISKD(Intramedullary Skeletal Kinetic Device; Orthofix,
McKinney, Tex);
• An implanted electrically activated motorized drive
(FITBONE; Wittenstein Igersheim, Germany).
• An Magnetically controlled distractors using an external remote
(PRECICE; Ellipse Tech., Irvine, USA).

81. ISKD:

82. ISKD:

83. Fitbone:

84. External remote for distraction of precice
nail:
• It takes 7 mins for
1mm distraction,
• So three times a day patient
uses this remote for 2.5
mins for accurate
lengthening
• Approved by FDA for use in
US.

85. .
For
LLD>15cm
Prosthetic
fitting
Amputation

86. Prosthetic fitting
• Significant discrepancies, deformed
functionally useless feet
• Discrepancies greater than 15-20cm
and femoral length less than 50%
• Fibular hemimelia with unstable
ankle
• PFFD: A/K prosthesis or BK
prosthesis with Van Nes
rotationplasty

87. Above Knee Prosthesis Below knee Prosthesis

88. Amputation:
• Significant length discrepancy or loss of sensation in foot,
• Poor underlying bone quality for lengthening,
• Dysfunctional/ painful limb.

89. Psychological and Social Factors
LLD
Patient
education
Rehabilitation
Family
support and
preparation
Psycological
support
Social support

90. References
• Tachdjian’s pediatrics Orthopedics , 4th edition
• Campbell’s Operative Orthopaedics, 13th edition
• Lovell and Winter’s Pediatric Orthopaedics, 7th edition

91. Thank you