Orthopaedics principles of bony deformity correction

1. Principles of Deformity
Correction
Dr Ankit Madharia
Junior Resident
NKPSIMS & RC

2. Deformity
• Definition:
• It’s the position of a limb/Joint, from which it cannot be
brought back to its normal anatomical position.

3. Deformity
• Described as abnormalities of
• Length
• Angulation
• Rotation
• Translation
• The location, magnitude, and direction of the deformity
complete the characterization of a bony deformity

4. Evaluation of Deformity
• Clinical Examination
• Radiological Examination
• Xrays
• CT Scans

5. Evaluation of Deformity : X Rays
• Radiographs of the lower limbs:
• Long films (51 Inches)
• Frontal plane (AP view)(Patella Forward)
Sagittal plane (Lateral view)

6. Evaluation of Deformity : X Rays
• Radiographs of the lower limbs:
• Long films (51 Inches)
• Frontal plane (AP view)(Patella Forward)
Sagittal plane (Lateral view)

7. Evaluation of Deformity : X Rays
• Radiographs of the lower limbs:
• Long films (51 Inches)
• Frontal plane (AP view)(Patella Forward)
Sagittal plane (Lateral view)

8. Evaluation of Deformity : X Rays
• Radiographs of the lower limbs:
• Long films (51 Inches)
• Frontal plane (AP view)(Patella Forward)
Sagittal plane (Lateral view)
Square the Pelvis in case of
Limb Length discrepancy

9. Evaluation of Deformity : CT Scan
• CT Scanogram

10. AXIS
• Each long bone has 2 axis :-
Mechanical axis
Anatomical axis.

11. MECHANICAL AXIS
• Straight line connecting the joint
center points of the proximal &
distal joints.
• Its always a straight line whether in
frontal or sagittal plane.

12. ANATOMICAL AXIS
• Is mid diaphyseal line.
• In a normal bone, the
anatomic axis is a
single straight line.
• In a malunited bone
with angulation, each
bony segment can be
defined by its own
anatomic axis

13. Limb Alignment
• It involves assessment of the frontal
plane mechanical axis of the entire limb
rather than single bones

14. Limb Alignment
• Mechanical axis deviation (MAD) is measured
as the distance from the knee joint center to
the line connecting the joint centers of the
hip and ankle.
• Normally, 1 mm to 15 mm medial to the knee
joint center.

15. Joint Orientation Lines
• Line representing the orientation of a joint
in a particular plane /projection.
• ANKLE
Frontal : along the flat subchondral line of
tibial plafond.
Sagittal : line from distal tip of posterior lip
to tip of anterior lip.

16. Joint Orientation Lines
• Knee:
• FRONTAL : along the subchondral line of
tibial plateau.
• Line tangential to most distal point on the
femoral condyle.
• SAGITTAL : along flat subchondral line of
plateau.
Line connecting 2 points where the
condyles meet the metaphysis.

17. Joint Orientation Lines
• Hip:
• FRONTAL : from tip of greater trochanter to
center of femoral head.
• Also from the centre of femoral head along
the anatomical axis of the femoral neck

18. • The relation between anatomical or
mechanical axes and the joint
orientation lines can be referred to as
joint orientation angles
Joint Orientation Angles

19. Centre of Rotation of Angulation (CORA)
• The intersection of the proximal axis and
distal axis of a deformed bone is called
the CORA , which is the point about
which a deformity may be rotated to
achieve correction.
• Either Anatomical or Mechanical axis can
be used to identify CORA.

20. Centre of Rotation of Angulation (CORA)
• Correction of angulation by rotating the bone
around a point on the line that bisects the
angle of the CORA (the “bisector”) ensures
realignment of the anatomic and mechanical
axes without introducing an iatrogenic
translational deformity.
• All points that lie on the bisector can be
considered to be CORAs because angulation
about these points will result in realignment
of the deformed bone

21. Evaluation of the Various Deformity Types
• Length
• Clinically
• Radiologically

22. Evaluation of the Various Deformity Types
• Angulation
• Characterized by Magnitude and direction of apex
• Identification of the CORA is key in characterizing
angular deformities and planning their correction
• Angulation can be in Frontal plane or in sagittal
plane or in oblique plane

23. Evaluation of the Various Deformity Types
• Angulation

24. Evaluation of the Various Deformity Types
• Rotation
• Clinically
• Radiologically
• Axial CT scans
• Characterised by
• Position
• Magnitude

25. Evaluation of the Various Deformity Types
• Translation
• Clinically
• Radiologically
• Axial CT scans
• Characterised by
• Plane
• Direction
• Magnitude
• Level

26. Treatment
• Following evaluation, the deformity is characterized by
its
• type (length, angulation, rotational, translational, or
combined),
• the direction of the apex (anterior, lateral, posterolateral,
etc.),
• the orientation plane,
• It’s magnitude,
• and the level of the CORA

27. Osteotomies
• 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
• location of the CORA
• Axis about which correction is performed (the correction axis),
• Location of the osteotomy

28. Results when using osteotomy
A.The CORA, the correction axis, and the osteotomy all lie at
the same location; the bone realigns through angulation
alone, without translation.
B.The CORA and the correction axis lie in the same location
but the osteotomy is proximal or distal to that location; the
bone realigns through both angulation and translation.
C.The CORA lies at one location and the correction axis and
the osteotomy lie in a different location; correction of
angulation results in an iatrogenic translational deformity.

29. Wedge osteotomy
• The type of wedge osteotomy is determined by the
location of the osteotomy relative to the locations of the
CORA and the correction axis

30. Wedge osteotomy
A.Opening wedge osteotomy.
• The CORA and correction axis lie on the cortex
on the convex side of the deformity.
• The cortex on the concave side of the deformity
is distracted to restore alignment, opening an
empty wedge that traverses the diameter of
the bone.
• Opening wedge osteotomy increases final bone
length.

31. Wedge osteotomy
B. Neutral wedge osteotomy.
• The CORA and correction axis lie in the middle of
the bone.
• The concave side cortex is distracted and the
convex side cortex is compressed.
• A bone wedge is removed from the convex side.
• Neutral wedge osteotomy has no effect on final
bone length.

32. Wedge osteotomies
C. Closing wedge osteotomy.
• The CORA and correction axis lie on the concave
cortex of the deformity.
• The cortex on the convex side of the deformity is
compressed to restore alignment, requiring removal
of a bone wedge across the entire bone diameter.
• A closing wedge osteotomy decreases final bone
length.

33. Dome Osteotomy
• In a dome osteotomy, the osteotomy site
cannot pass through both the CORA and
the correction axis. Thus, translation will
always occur when using a dome
osteotomy.

34. Dome Osteotomy
Ideally, the CORA and correction axis are
mutually located with the osteotomy
proximal or distal to that location such
that the angulation and obligatory
translation that occurs at the osteotomy
site results in realignment of the bone
axis.

35. Dome Osteotomy
When the CORA and correction axis are
not mutually located, a dome osteotomy
through the CORA location results in a
translational deformity.

36. Dome osteotomy
the CORA and correction axis are mutually located with
the osteotomy distal to that location in all of these
examples.
A.Opening dome osteotomy.
The CORA and correction axis lie on the cortex on the
convex side of the deformity.
Opening dome osteotomy increases final bone length.

37. Dome osteotomy
B. Neutral dome osteotomy.
The CORA and correction axis lie in the middle of the
bone.
Neutral dome osteotomy has no effect on final bone
length..

38. Dome osteotomy
C. Closing dome osteotomy.
The CORA and correction axis lie on the concave cortex of
the deformity.
A closing dome osteotomy decreases final bone length
It can result in significant overhang of bone that may
require resection

39. Treatment By Deformity type : Length
• Acute distraction or compression methods obtain
immediate correction of limb length by acute
lengthening with bone grafting or acute shortening,
respectively
• Gradual correction techniques for length deformities
typically use Ilizarov external fixation/ LRS

40. Treatment By Deformity type : Angulation
• Correction of angulation deformities involves
making an osteotomy, obtaining realignment of the
bone segments, and securing fixation during healing.
• Alternatively, the correction may be made gradually
using external fixation to both restore alignment and
provide stabilization during healing

41. Treatment By Deformity type : Rotation
• Correction of a rotational deformity requires an
osteotomy and rotational realignment followed by
stabilization.

42. Treatment By Deformity type : Translation
• Translational deformities may be
corrected in one of three ways.

43. Thank you