1. Hadi H. MD Knee surgery fellowship Arak & Iran UMS
Role of osteotomy in patellar mal-tracking
Hadi H. MD Knee surgery fellowship Arak & Iran UMS

2. Patellar mal-alignment may be defined as a
Introduction
Patellar mal-alignment may be defined as a
Translational or rotational deviation of the patella relative to any axis
It is caused by an abnormal relationship between
Patella
Soft tissues surrounding the patella
Femoral and tibial osseous structures

3. Introduction Eckhoff stated that
‘‘the patella is a passive component of the extensor mechanism, where the static and dynamic relationships of the underlying tibia and femur determine the patellar tracking pattern’’
Eckhoff DG,(1997). Clin Orthop Relat Res

4. The source of such abnormal patellar kinematics may be
Introduction
The source of such abnormal patellar kinematics may be
Peri-patellar tissue tightness or laxity
Osteo-chondral dysplasia (trochlear)
Bony abnormalities of the patella

5. The source of such abnormal patellar kinematics may be
Introduction
The source of such abnormal patellar kinematics may be
Rotational mal-alignment of the femur and tibia
Patella alta and patella baja
Inflexibility or weakness of the quadriceps hamstrings, and iliotibial band (ITB), Achilles tendon

6. Well-known risk factors for symptomatic PF mal-alignment include
Introduction
Well-known risk factors for symptomatic PF mal-alignment include
Genu valgum
Patella alta
Trochlea dysplasia
Increased TT- TG distance
Femur or tibia mal-rotation

7. The key to the indications for surgical treatment is
Introduction
The key to the indications for surgical treatment is
Diagnosis of the specific anatomic defects that cause the patient's symptoms
This underscores the importance of the history and physical examination
Abnormal findings are often quite subtle, leading to a major problem

8. Mal-alignment Deviations in normal limb alignment
Knee joint flexion-extension axis advancing sideways
While the body moves forward

9. These deviations include
Mal-alignment
These deviations include
Excess femoral anteversion or retroversion
Excess internal or external tibial torsion
Genu valgum or varum
Foot hyper-pronation
Achilles contracture

10. Rotational Mal-alignment
Torsional deformities of the femur and/or tibia
Often go unrecognized in both adolescents and adults
Who present with anterior knee pain, and patellar mal-tracking and/or instability

11. Rotational Mal-alignment
foot progression angle (FPA)
Averages 10° to 15°
Remains similar despite differences in the torsion of the tibia or femur
Hip rotation must vary if the torsion of the long bones changes and the FPA stays constant

12. Rotational Mal-alignment
Constant foot progression angle (FPA)
is likely because
Proper ankle dorsiflexion cannot occur during gait if the ankle joint axis is not aligned with the direction of forward movement
Most stable position of the foot on the ground

13. Rotational Mal-alignment
If the knee joint twists inward because the femur twists inward
Lateral pull on the quadriceps
Lateral displacement pull on the patella
Strain on the medial MPFL
Are increased

14. rotational Mal-alignment
A similar increase of inward pointing of the knee joint
Excess external tibial torsion when the foot is pointed forward

15. Rotational Mal-alignment
Compression on the lateral patellar facet is increased
Compression on the medial patellar facet is decreased

16. Rotational mal-alignment
The clinical presentation may be
Pain
Instability
Arthrosis
Combination of these problems

17. Rotational mal-alignment
If this force is great
If the trochlear support is reduced
Medial ligaments may fail, resulting in lateral patellar instabilIty

18. Rotational mal-alignment
If the trochlear support is normal
The ligament may not fail but the articular load may increase, causing arthrosis
Pain in the medial retinaculum is a common symptom caused by this increased stress

19. Rotational mal-alignment
The dynamic picture is much worse
Ante-version puts the greater trochanter pointing posteriorly
So there is no hip abduction power and the pelvis collapses

20. Rotational mal-alignment
In an attempt to increase hip power and put the foot forward
The knee joint must point inward
Even more when there is an increase in hyper-pronation

21. Rotational mal-alignment
Yoshioka and associates (1989, J. Orth. Rech.) found in male & female
Identical
femoral ante-version
equal genu valgus
But an increase in
external tibial torsion
foot external rotation
in females over males

22. Rotational mal-alignment
This increase in external foot rotation may account for
The apparent increased genu valgus in females
The increased incidence in PF symptoms in females
Even the increased incidence of ACL tears in females

23. Rotational mal-alignment
Biomechanical study that measured PF contact pressures concluded that
If an angular deformity and a torsional deformity coexist, the rotatory component causes the greater PF changes
Fujikawa, K;Biomechanics of the patello-femoral joint. Eng Med ,1983

24. Mar-rotation Treatment
The goal of operative treatment is to normalize the biomechanics through restitution of normal anatomy
The morbidity of surgery may dictate otherwise
When multiple anatomic abnormalities exist, it is not known which may be more important

25. Indication Surgery is indicated
Torsion of the femur or tibia exceeding 30° from normal
Surgery is beneficial
Torsion exceeding 20° from normal
Abnormality less than 20°, the accuracy of surgery or the morbidity may not justify the smaller biomechanical changes

26. Indication Clinical symptoms with Angle > 2SD on CT Scan
Rotational osteotomy

27. Tibial tubercle transfer (TTT)
Distal realignment procedures modify the
Medial-lateral
Anterior-posterior
Proximal-distal positions
of the patella by transfer of the tibial tubercle

28. Distal realignment (TTT)
The primary contraindication
Absence of a distinct anatomic defect
Because the goal of surgery is to restore normal anatomy of the extensor mechanism

29. Distal realignment (TTT)
A specific contraindication to extensor mechanism surgery is the presence of
Excessive hip anteversion or
Abnormal external tibial torsion
In these patients, a femoral or tibial derotation osteotomy may be indicated

30. Distal realignment Patella alta Congenital abnormality
An increased vertical position of the patella
Due to an elongated patellar tendon
Patella not engaging within the trochlea until a mid-flexion range of motion
Patella instability or pain

31. Patella alta
Decrease in PF joint contact area at all knee flexion angles
Risk for early PF arthritis
In most patients, other abnormalities of the extensor mechanism are usually present

32. Cartilage lesions typically
Patella alta
Cartilage lesions typically
Infero-lateral portion of the lateral patella facet
Lateral region of the trochlea

33. Distal realignment (Distalization)
Indications for surgery
Recurrent dislocations
Anterior knee pain
that has not responded to conservative treatment

34. Distal realignment (Distalization)
Patient is advised that symptoms of anterior knee pain related to the arthritis will continue
It is thus preferable to correct a symptomatic patellar alta condition early prior to the development of cartilage deterioration

35. Distal realignment (Distalization)
The goal
Restore a normal patellar height index
Patello-trochlear contact (~30% of the inferior patellar articular cartilage) has engaged the trochlear at full extension

36. Distal realignment (Distalization)
When a distal transfer of the patellar tendon
Tenodesis of the tendon at the tibial insertion site would restore normal tendon length
Decrease side-to-side patellar mobility, given the high percentage of associated trochlear dysplasia

37. Distal realignment (AMZ)
Indications (Fulkerson)
Patello-femoral pain
Either lateral or distal patellar arthrosis
Lateral subluxation/dislocations of the patella

38. Distal realignment (AMZ)
The ideal candidate is someone with
Lateral patellar tilt (and/or subluxation) associated
With grade III or IV articular degeneration
Localized to the lateral and/or distal medial patellar facets

39. Distal realignment (AMZ)
Contraindications
No mal-alignment
Occult medial patella subluxation
Diffuse patellar articular cartilage disease (especially at the proximal pole)
Mild articular changes (grade I or II) with tilt, and no subluxation
May be better treated with an isolated lateral release

40. In patella mal-tracking
Conclusion
In patella mal-tracking
Abnormal findings are often quite subtle, but combinations are surprisingly common
Torsional deformities are often unrecognized
For local cartilage lesions distal realignment may be appropriate
Exact pre-op planning is necessary for satisfactory outcome

41. Thanks for your attention