Malunion orthopaedics, Dror paley

1. TOPIC - MALUNION
MODERATOR – Dr. MAHESH
PRESENTER – Dr. KARTHIK M V

2. • A Malunited fracture is one that has healed with the fragments in a
non-anatomical position.
• A Malunited fractures becomes surgically significant only when it
impairs functions.
• Deformity – it’s the position of a limb/ joint, from which it cannot be
brought back to its normal anatomical position.

3. • Whether the deformity is unsightly or not it can impair functions in
several ways
1. abnormal/ irregular weight transfer -> arthritis.
2. rotation/ angulation deformity -> interfere gait.
3. overriding of fragments -> shortening.
4. movements of neighbouring joints may be blocked.

4. Causes
• Improper closed reduction of fractures
• Improper immobilization techniques
• Treatment by traditional bone setters

5. Most common sites of malunion
• Supracondylar humerus fractures
• Distal radius fracture
• Inter trochanteric fractures
• Clavicle fractures

6. • Deformity can be described as abnormality of
1. Length
2. Angulation
3. Rotation
4. Translation

7. Length
• Deformities of length include shortening and
overdistraction.
• Shortening after an injury may be a result
from bone loss or overriding of healed
fracture fragment.
• Overdistraction at the time of fracture
fixation may result in a healed fracture with
overlengthening of the bone.

8. Angulation
• Angulation deformity of the diaphysis is often associated with limb
malalignment.
• The identification of CORA is the key in characterizing angular
deformities.

9. Rotation
• A rotational deformity occurs about the
longitudinal axis of the bone.
• Rotational deformities are described in terms of
their magnitude and the position ( IR/ER) of the
distal segment relative to the proximal segment.

10. Translation
• Translational deformities may result from malunion following either a
fracture or an osteotomy.
• The direction of a translational deformity is described in terms of the
position of the distal segment relative to the proximal segment.

11. • The objective of surgery for malunion is to restore function.
Operative treatment for malunion of most fractures should not be
considered until 6 to 12 months after the fracture has occurred.
However, in intraarticular fractures, surgery may be required sooner
if satisfactory function is to be restored.

12. AXIS
• Each long bone has 2 axis
1. Mechanical axis
2. Anatomic axis

13. • MECHANICAL AXIS - The mechanical axis
of a bone is defined as the straight line
connecting the joint center points of the
proximal and distal joints.
• Mechanical axis is always a straight line
connecting two joint center points
MECHANICAL AXIS

14. ANATOMIC AXIS
• ANATOMIC AXIS - The anatomic axis of a long
bone is the mid-diaphyseal line of that bone.
• In straight bones, the anatomic axis follows
the straight middiaphyseal path.

15. In Tibia Mechanical and
Anatomic axis are
Parallel, but not same.
The tibial anatomic-
mechanical angle (AMA)
is 0°
The Anatomic axis
slightly medial to the
Mechanical axis.

16. In the femur, the
mechanical and anatomic
axes are different and
converge distally.
The normal femoral AMA
is 7±2°.

17. Joint orientation lines
• It is a line representing the orientation of
a joint in a particular plane/ projection
1. ANKLE
Frontal – along the flat subchondral line
of tibial plafond
Sagittal – line drawn from distal tip of
posterior lip to distal tip of anterior lip of
tibia

18. 2. KNEE
Frontal
 Proximal tibia - along the
subchondral line of tibial plateau.
 Distal femur – tangential line to
the most distal points on the
convexity of the two femoral
condyles.

19. 2. KNEE
Sagittal
 Proximal joint line of the tibia is
drawn along the flat subchondral line
of the plateaus.
 Distal femur - straight line connecting
the two points where the femoral
condyles meet the metaphysis of the
femur.

20. 3. HIP
Line drawn from tip of greater
trochanter to center of femoral
head in frontal plane.

21. Joint Orientation Angles
• It is the angle formed between the joint orientation line
and either the mechanical or anatomic axis.
 m – mechanical axis
 a – anatomic axis
 M – medial
 L – lateral
 A – anterior
 P – posterior
 F – femur
 T – Tibia

22. Joint Line Convergence angle (JLCA)
• The angle formed between joint
orientation lines on opposite sides of the
same joint.
• In knee and ankle joints these lines are
normally parallel.

23. • Joint Alignment refers to collinearity of the hip, knee and ankle joints.
• Joint Orientation refers to the position of each articular surface
relative to the axes of the individual limb segments (tibia and femur).
• Alignment and Orientation can be best judged using long standing AP
x-rays of lower limb in one single cassette.

24. Mechanical axis of lower limb
• In frontal plane, the line passing from the
center of the femoral head to the center of
the ankle plafond is called the mechanical
axis of the lower limb
• Typically passes immediately medial to the
center of the knee.
• Malalignment occurs when the center of the
knee does not lie close to this line.

25. Mechanical axis deviation (MAD)
• The distance between the mechanical axis of the
lower limb and the center of the knee in the frontal
plane is the MAD.
• In a retrospective study of 25 knees in adult
patients of different ages, the normal MAD was
9.7±6.8 mm medial (Paley et al 1994)

26. Center of rotation of angulation(CORA)
• It is the intersection of the proximal axis and distal
axis of a deformed bone is called as CORA.
• It is the point about which a deformity may be
rotated to achieve correction.
• Either anatomic or mechanical axis can be used.

27. • The axis line of the proximal bone segment is called
the proximal mechanical axis (PMA) or proximal
anatomic axis (PAA) line,
• The axis line of the distal bone segment is called the
distal mechanical axis (DMA) or distal anatomic axis
(DAA) line.
• The angle formed by the two axes at the CORA is a
measure of angular deformity in that plane called as
Magnitude of angulation (mag).

28. • To decide whether this is uniapical or
multiapical angulation
a. CORA corresponds to the obvious
deformity level: If the intersection of
the proximal and distal axes
corresponds to the obvious level of
deformity, the intersection point is the
CORA and deformity is uniapical (in the
respective plane)

29. b. CORA doesn’t corresponds to the obvious deformity:
There is more than one apex of angulation (multiapical)

30. • b. CORA doesn’t corresponds to the obvious deformity:
Translational deformity

31. Radiographic assessment
 Full length AP view (frontal plane)
 Full length LAT view (sagittal plane).
 The true AP view of the knee is obtained in the knee forward
position (patella centered on the femoral condyles)
 The correct method is to orient the patella forward, irrespective of
the foot position

35. • Sagittal plane
a) Orthogonal LAT view of the knee
with the patella in the knee forward
position (true AP) should show the
back of the femoral condyles not
overlapping.
b) LAT view obtained with the knee in
3°-5° of external rotation has the
femoral condyles overlapping.

36. The knee is kept in full
extension. To see the proximal
femur, the pelvis is rotated
posteriorly 30°- 45° without
rotating the knee on the study
side.

37. • Limb length Discrepancy
Elevate the shorter limb on blocks
adjusted to the approximate
discrepancy.
Prevents the patient from using
compensatory mechanisms such as
contralateral knee flexion, ipsilateral
ankle equinus, pelvic tilt.
compensatory mechanisms cause
uneven loading of the limbs and may
alter the alignment and leg length
measurement on the radiograph

38. • When knee joint laxity is present, varus and valgus stress radiographs
Bimanual varus single-leg stress method Bimanual valgus single-leg stress method

39. Bilateral varus stress method using fulcrum block Bilateral valgus stress method using fulcrum belt

40. • When treating malunions, the following facts must be considered
The first in importance is alignment.
The second is rotation.
The third is restoration of normal length.
The fourth and least important is the actual position of the
fragments.

41. Angulation Correction Axis (ACA)
• The axis line around which the correction is
performed is the Angulation Correction Axis
(ACA).
• If the ACA-CORA is on the convex cortex of
the osteotomy line, an opening wedge
correction is achieved.

42. • If the ACA-CORA is on the concave
cortex of the osteotomy line, a
closing wedge correction is
achieved

43. BISECTOR LINES
• The bisector is a line that passes through
the CORA and bisects the angle formed by
the proximal and distal axes.
• The angle formed by axes are proximal,
distal, medial and lateral.
• The proximal and distal angles are equal to
each other so are medial and lateral.
• The transverse bisector line (tBL) bisects
the medial-lateral angles.

44. • The longitudinal bisector line
(lBL) bisects the proximal-distal
angles.
• The tBL and lBL are always
perpendicular to each other.

45. Osteotomy
• An osteotomy is used to separate the deformed bone segments to
allow realignment of the anatomic and mechanical axes.
• The ability of an osteotomy to restore alignment depends on
a. CORA
b. the correction axis (ACA)
c. the location of the osteotomy.

46. OSTEOTOMY RULE 1
• When the osteotomy line and
ACA pass through any of the
CORAs, realignment occurs
without translation

47. OSTEOTOMY RULE 2
• When the ACA is through the
CORA but the osteotomy is at
a different level, the axis will
realign by angulation and
translation at the osteotomy
site.

48. OSTEOTOMY RULE 3
• When the osteotomy and
ACA are at a level above or
below the CORAs, a
translational deformity will
result.

49. WEDGE OSTEOTOMY
• The type of osteotomy is determined by location of osteotomy
relative to locations of the CORA and the ACA
• The CORA and ACA may lie on concave or convex side of cortex, or
in the middle of the bone.

50. OPENING WEDGE OSTEOTOMY
• The ACA-CORA lie on the convex cortex of the deformity,
the correction will result in an opening wedge osteotomy.
• All points on the convex side of the ACA-CORA will be
compressed, whereas all points on the concave side will be
distracted.
• In an opening wedge osteotomy, the cortex on the concave
side is distracted to restore the alignment.
• There is a wedge-shaped bone defect with its base on the
concave side
• An opening wedge osteotomy increases the bone length.

52. Closing Wedge Osteotomy
• The ACA-CORA lie on the concave cortex of the
deformity, the correction will result in an closing
wedge osteotomy.
• In a closing wedge osteotomy, the cortex on the
convex side is compressed, this involves removal of a
bone wedge across the entire bone diameter to
restore alignment.
• A closing wedge osteotomy decreases bone length.

54. Neutral Wedge Osteotomy
• The ACA-CORA lie in the middle of the bone, the
correction will result in an closing wedge osteotomy.
• A bone wedge is removed from the convex side to allow
realignment.
• The cortex on the convex side is compressed and
concave side is distracted.
• Has no effect on bone length.

56. Dome Osteotomy
• The type of dome osteotomy is also determined
by the location of the CORA and the correction
axis relative to the osteotomy.
• the CORA and correction axis are mutually
located such that the angulation and obligatory
translation that occurs at the osteotomy site
results in realignment.

57. • when the CORA and correction axis are
not mutually located results in a
translational deformity.

58. • When the CORA and correction axis lie on
the convex cortex of the deformity, the
correction will result in an opening dome
osteotomy.
• The translation that occurs in an opening
dome osteotomy increases final bone
length.
Opening Dome Osteotomy

59. Neutral Dome Osteotomy
• When the CORA and correction axis lie
in the middle of the bone, the
correction will result in a neutral dome
osteotomy.
• A neutral dome osteotomy has no
effect on bone length.

60. Closing Dome Osteotomy
• When the CORA and correction axis
lie on the concave cortex of the
deformity, the correction will result
in a closing dome osteotomy.
• The translation that occurs in a
closing dome osteotomy decreases
final bone length.

61. Treatment by deformity type
1. Length
• Acute distraction or compression methods obtain immediate
correction of limb length by acute lengthening with bone grafting or
acute shortening, respectively.
• The extent of acute lengthening or shortening that is possible is
limited by the soft tissues.

62. • Acute distraction treatment methods involve distracting the bone ends to
the appropriate length, placing a bone graft in the resulting space between
the bone segments, and stabilizing the construct to allow incorporation of
the graft.
(1) autogenous cancellous or cortical bone grafts
(2) vascularized autografts
(3) bulk or strut cortical allografts
(4) mesh cage-bone graft constructs
(5) synostosis techniques.
• A variety of internal and external fixation treatment methods may be used
to stabilize the construct during graft incorporation

63. • In the upper extremity, up to 3 to 4 cm of shortening is generally well
tolerated
• In the lower extremity, up to 2 cm of shortening may be treated with
a shoe lift
• Tolerance for a 2- to 4-cm shoe lift is poor for most patients.
• Most patients with shortening of greater than 4 cm will benefit from
restoration of bone length.

64. • Acute compression methods are used to correct overdistraction
deformities by first resecting the appropriate length of bone,
approximating the bone ends, and then stabilizing the approximated
bone ends under compression.
• For the paired bones of the forearm and leg, the unaffected bone
requires partial excision to allow shortening and compression of the
affected bone. For example, partial excision of the intact fibula is
necessary to allow shortening and compression of the tibia.

65. • Gradual correction techniques for length deformities typically use
tensioned-wire (Ilizarov) external fixation.
• Gradual correction methods for length deformities can also be used
to correct associated angular, translational, or rotational deformities
simultaneously while restoring length.
• Gradual distraction involves the creation of a corticotomy (usually
metaphyseal) and distraction of the bone segments at a rate of 1 mm
per day using a rhythm of 0.25 mm of distraction repeated four times
per day. The bone formed at the distraction site is formed through the
process of distraction osteogenesis,

66. 2. Angulation
• Correction of angulation deformities involves making an osteotomy,
obtaining realignment of the bone segments, and securing fixation
using internal or external fixation methods during healing.
• Angulation deformities in the diaphysis are most amenable to
correction using a wedge osteotomy at the same level as the
correction axis and the CORA.
• Juxta-articular angulation deformities may require a dome osteotomy
with location of the osteotomy proximal or distal to the level of the
correction axis and the CORA.

67. 3. Rotation
• Correction of a rotational deformity requires an osteotomy and
rotational realignment followed by stabilization using internal or
external fixation.
• The level of deformity in rotational limb deformities is often difficult
to determine.
• Other factors involving are muscle and tendon line of pull, and the
location of neurovascular structures and soft tissues

68. 4. Translation
• Translational deformities may be corrected in
one of three ways.
1. A single transverse osteotomy may be made
to restore alignment through pure translation
without angulation. the transverse osteotomy
does not have to be made at the level of the
deformity

69. A single oblique osteotomy may be made at the
level of the deformity to restore alignment and
gain length.

70. • Two wedge osteotomies at the level of the
respective CORAs and angular corrections of
equal magnitudes in opposite directions may be
used to correct a translational deformity.
• Internal or external fixation may be used to
provide stabilization following acute correction
of translational deformities
• Gradual correction may be carried out using
external fixation

71. Combined deformities
• Combined deformities are characterized by the presence of two or
more types of deformity in a single bone.

72. Treatment by method
Plate and screw fixation
• Advantages
a. rigid fixation
b. correction of deformities under direct visualization
• Disadvantages
a. extensive soft tissue dissection
b. limitation of early weight-bearing

73. Intramedullary nail
• IMN is particularly useful in lower extremity because of the strength
and load-sharing characteristics.
• IMN is ideal for diaphyseal deformities are being corrected.
• IMN implants are excellent for osteoporotic bones where screw
purchase maybe poor

74. Ilizarov’s Techniques
• Primarily percutaneous, minimally invasive, and typically require only
minimal soft tissue dissection.
• Promote the generation of osseous tissue.
• Can be used in the presence of acute or chronic infection.
• Allow for stabilization of small intra-articular or periarticular bone
fragments.

75. • Allow simultaneous deformity correction and enhancement of bone
healing.
• Allow immediate weight bearing.
• Allow augmentation or modification of the treatment as needed
through frame adjustment.
• The Ilizarov external fixator can be used to reduce and stabilize
virtually any type of deformity, including complex combined
deformities.
• Restore limb length in case of limb shortening.

76. Distraction Lengthening
• Distraction osteogenesis
• Distraction produces a tension-stress effect that causes
neovascularity and cellular proliferation in many tissues, including
bone regeneration primarily through intramembranous bone
formation.

77. • Factors affecting Distraction osteogenesis
1. Corticotomy performed using low energy technique to avoid
necrosis
2. Distraction of the metaphyseal or metaphyseal– diaphyseal regions
has superior potential for regenerate bone formation relative to
diaphyseal sites.
3. A latency period of 7 to 14 days following the corticotomy and
before beginning distraction is recommended.
4. The external fixator construct must be very stable.
5. Since the formation of the bony regenerate is slower in some
patients, the treating physician should monitor the progression of
the regenerate on plain radiographs and adjust the rate and rhythm
of distraction accordingly

78. References
• Principles of Deformity Correction, DROR PALEY.
• Rockwood and Green’s Fractures in Adults.
• Campbell’s OPERATIVE ORTHOPAEDICS.
• Essential Orthopaedics Principles & Practice, Manish Kumar Varshney

79. THANK YOU