Trochlear dysplasia -anatomy ,classification , radiological finding ,treatment

1. Pedagogy
Topic : Trochlear Dysplasia
Dr.Madhavan

2. LESSON PLAN
• Name of the lecturer :Dr. MADHAVAN
• Date :25/08/2020
• Class: Orthopaedic Post Graduates, interns
• Number of students : 24
• Time :8mins
• Subject : Orthopaedics
• Topic :Trochlear Dysplasia

3. SPECIFIC LEARNING
OBJECTIVES
• Each Students should be able to
1. Describe the anatomy, radiological findings , Trochlear
dysplasia classification.
2. Describe the treatment for Trochlear dysplasia
At the end of the class, With out mistakes

4. Sl
no
Content Method and
media
Time
taken
Evaluation
1 • Anatomy
• Radiology
Power point
presentation
3 Questions
and answers
2. •Classification Power point
presentation
2 Questions
and answers
3. •Treatment
•Summary
Power point
presentation
3 Questions
and answers
Assignment :All students should able to describe the Type of
Trochlear dysplasia and their radiological findings

5. • Trochlear groove consists of a shallow depression
5–6 mm
• Bound by the medial and the lateral femoral
articular surfaces
• Prominent lateral surface of trochlear groove
projects anteriorly
• Variation in the structural anatomy of the trochlear
groove predispose to maltracking
INTRODUCTION

6. Medial
Trochlear
edge
Lateral
Trochlear
edge
(anteriorly )
Skyline view

7. • The normal shape of the trochlear groove is concave
• This allows the patella to glide down the central
aspect of the distal femur
• This is important because the patella serves as a
fulcrum to increase the overall strength and
efficiency of the quadriceps muscles of the thigh

8. NORMALY
CONCAVE IN
SHAPE

9. • The MPFL acts as the major restraint to lateral
patellar translation from full extension through the
first 20°–70° of knee flexion
• The trochlea serves as the main restraint throughout
the flexion
• A shallow trochlea is said to be dysplastic if the
sulcus angle, taken on an axial radiograph with the
knee flexed to 30°, is greater than 145°

10. Congruence
angle -6
degrees
Sulcus
angle 137
degrees
patellofemoral
angle

11. X-RAY VIEWS
INFRAPATELLER VIEW/ HUGHSTON
Angled 45 degrees cephalad

12. AXIAL VIEW
The beam is directed caudal and
inferior, With 45 degrees knee
flexion

13. Skyline view
Patella
Settegast view

14. • Trochlear dysplasia is one of the major anatomical
cause for recurrent patellar dislocation
• It has been reported to be present in 85–96% of
patients with a patellar dislocation events

15. Dejour identified multiple radiographic
parameters that are present in Trochlear dysplasia as
a predisposing factors
(1)Trochlear depth < 4 mm or < 3 mm on MRI
(2) Patellar tilt > 20°
(3) Spur height > 5 mm
(4) Trochlear angle > 145°

16. TROCHLEAR DEPTH
<3 MM
MEANS
TROCHLEAR
DYSPLASIA

17. PATELLAR TILT

18. NORMAL TROCHLEA DYSPLASTIC TROCHLEA

19. Dejour Classification of Trochlear
Dysplasia
Type A: Crossing sign / trochlea is shallower than
normal/ but still symmetric and concave.
Reff: The sulcus deepening trochleoplasty—the Lyon’s procedure, Int Orthop 34:311, 2010.)

20. CROSSING SIGN
• when the line of the Trochlear groove crosses the
anterior border of one of the condyle

21. Type B: Crossing sign + trochlear spur/ trochlea is flat
or convex in axial images.
Reff: The sulcus deepening trochleoplasty—the Lyon’s procedure, Int Orthop 34:311, 2010.)

22. Type C: Crossing sign + double-contour sign
representing sclerosis of the subchondral bone of the
medial hypoplastic facet/ lateral facet is convex
Reff: The sulcus deepening trochleoplasty—the Lyon’s procedure, Int Orthop 34:311, 2010.)

23. DOUBLE CONTOUR SIGN
• A double line at the anterior aspect of condyles that
occurs if the medial femoral condyle is hypoplastic

24. Type D: Combination of all signs—crossing sign,
supratrochlear spur, and double contour
Sign+ cliff pattern-in axial view
Reff: The sulcus deepening trochleoplasty—the Lyon’s procedure, Int Orthop 34:311, 2010.)

25. • Trochlear dysplasia: Crossing sign
• Sulcus angle >145 degrees
• MPFL reconstruction
• Trochleoplasty

26. TREATMENT
Dejour sulcus-deepening trochleoplasty
Type ?
SUBCHONDRAL
BONE CUT AND
MAKING A
DEFECT
FIXED WITH
BONE
STAPLES

27. Measuring the thickness
• below osteochondral edge

28. Before
After
Make a gentle cut with osteotome and remove the sub chondral bone with rongeur

29. SUMMARY
• Trochlear dysplasia is one of the main cause for
recurrent patellar dislocation
• TD accounts for around 95% of recurrent patellar
dislocation
• Normal sulcus angle 137 0 ± 6 0
• Normal congruence angle -6 0
• Normal trochlear depth 1cm
• DEJOUR classification for trochlear dysplasia
• Type A-crossing sign, B-spur , C-double contour sign,
D-ciff
• Treatment –Dejour trochleoplasty + immediate
passive mobilization

30. Crossing sign Supratrochlear
spur
Double contour sign
Medial condyle hypoplasia Cliff and convex lateral condyle

31. • Thank you