An MRI Based Double Blinded Obseravational Study of Posterior Tibial Slope in Indian Population-Dr. Shyam Sundar et al

1. What is our slope ?- An MRI based double blinded
observational study of posterior tibial slope in Indian
population
Shyam sundar .,MS,
Capt .Sarthak patnaik .,MS,
Bobur ubaydullaev.,MS,
Karthik selvaraj.,MS,DNB
Vinodh kolandavelu.,D.ortho, Mch ,
David .v.Rajan .,MS, DNB, MNAMS, FRCS
Ortho One Orthopaedic Speciality Centre, Coimbatore , India

2. • ACL injuries remain prevalent and result in
substantial short and longterm knee disability
Renstrom P et al., British journal of sports medicine.
2008;42(6):394-412.

3. Risk factors for ACL injury
Extrinsic factors
1. Playing surface ,
2. Shoe type ,
3. Type of sport and
4. Environmental conditions
Alentorn-Geli E et al., Knee surgery, sports traumatology, arthroscopy
2009;17(8):859-79.
Dragoo JL et al., The American journal of sports medicine. 2012;40(5):990-5.
Lambson RB et al.,The American journal of sports medicine. 1996;24(2):155-9.
Orchard J et al.,The American journal of sports medicine. 2001;29(2):196-200.

4. Intrinsic factors
1. Notch width,
2. Subtalar pronation,
3. Changing hormonal levels,
4. Poor neuromuscular control,
5. Ligamentous laxity ,
6. High body mass index,
7. Sex and genu recurvatum,
8. Increased anterior pelvic tilt,
9. Femoral anteversion
10.Tibial slope
Beynnon BD et al., The American journal of sports medicine. 2005;33(11):1751-
67.
Anderson AF et al.,The journal of arthroscopic & related surgery.
2007;23(3):261-8.
Allen MK et al., Journal of athletic training. 2000;35(4):403-6.

5. • Tibial slope is defined as the angle formed at the
intersection of a line parallel to the posterior tibial
inclination and a line that bisects the diaphysis of the tibia
Giffin JR, Vogrin TM, Zantop T, Woo SL, Harner CD. Effects of
increasing tibial slope on the biomechanics of the knee. Am J
Sports Med 2004;32:376-382.

6. 10/12/2014
Purpose
 What is the slope in indian population???
 Identify the slope value beyond which risk factor for ACL is high
 If there is any difference in the values with respect to gender

7. Methodology
Retrospective Double blinded MRI based observational study
• Inclusion criteria :-
Skeletally mature patients , with clear 1.5 tesla image of the affected
knee joint
• Exclusion criteria :-
multi-ligament injury
inflammatory disorders
aspetic necrosis of femoral or tibial condyle
tumours involving the joint and
presence of significant osteophytes deranging the tibial plateau

8. • This was a double blinded study which was conducted
between January 2013 to June 2013 ( 6months ) by two
fellowship trained orthopaedic surgeons.
• Total of 489 patients were studied in which 199 patients had
ACL injury and remaining 290 had intact ACL.
MRI scans were obtained on a 1.5 Tesla MRI scanner (vipro GE ,
USA ) using the following parameters: PD FAT sup, coronal plane,
slice thickness: 4 mm , 0.5mm space , matrix 352 X 224, TE: 13.6
ms, TR: 1700-2000 ms; T2 saggital & axial images, thickness -
3.5mm , space 0.5mm, matrix - 352 X 224, TE -86ms , TR -
4200ms.

9. How to measure the posterior
tibial slope ?
• MRI based measurement
• Proposed by Hashemi et al
• The Geometry of the Tibial Plateau and Its Influence on the
Biomechanics of the Tibiofemoral Joint. J Bone Joint Surg Am.
2008;90:2724-34

11. Jae Ho Yoo, MD et al : Anatomical
References to Assess the Posterior Tibial
Slope in Total Knee Arthroplasty: A
Comparison of 5 Anatomical Axes. The
Journal of Arthroplasty Vol. 23 No. 4 2008
The anatomical axis most parallel to
the sagittal MA was the PAA.
Taken as a reference point
measuring the slope in regular short
radiographs

14. Observer variation ???...
• A pilot study was done to measure the tibial slope in 100
knees so as to assess the inter and intra observer reliability.
• As the kappa coefficiency factor was excellent for inter and
intra observer measurements (0.89 and 0.90 resp ) ,

15. Results

19. Discussion
• ACL is the primary passive restraint to anterior tibial
translations and loads
Butler DL. et al .,Kappa Delta Award paper. Journal of
orthopaedic research 1989;7(6):910-21.
Markolf KL et al., Journal of orthopaedic research
1995;13(6):930-5.

20. Suggested that the tibial geometry may have a substantial influence on the
tibiofemoral biomechanics when knee is subjected to external loads

21. • Considered as an important risk factor for ACL injury
Feucht MJ et al.,Knee surgery, sports traumatology, arthroscopy
2013;21(1):134-45.
Hashemi Jet al.,The American journal of sports medicine. 2010;38(1):54-62.
Khan MS et al., International orthopaedics. 2011;35(8):1251-6.

23. AJSM 2004

24. increase in posterior tibial slope from 5° to 20° resulted in
anterior tibial translation from 2.1mm to 4.6mm and superior
translation of 1.6mm to 4.1mm.

25. Markolf KL et al : Combined knee loading states that generate high anterior cruciate
ligament forces. Journal of orthopaedic research 1995;13(6):930-5.
Shelbourne KD et al : Long-term evaluation of posterior lateral meniscus root tears left in
situ at the time of anterior cruciate ligament reconstruction. The American journal of
sports medicine. 2011;39(7):1439-43.
Shao Q et al : Estimation of ligament loading and anterior tibial translation in healthy and
ACL-deficient knees during gait and the influence of increasing tibial slope using EMG-driven
approach. Annals of biomedical engineering. 2011;39(1):110-21.

26. No significant difference
Meister K, Talley MC, Horodyski MB, Indelicato PA, Hartzel JS, Batts J. Caudal
slope of the tibia and its relationship to noncontact injuries to the ACL. The
American journal of knee surgery. 1998;11(4):217-9..
Hudek R, Fuchs B, Regenfelder F, Koch PP. Is noncontact ACL injury associated
with the posterior tibial and meniscal slope? Clinical orthopaedics and related
research. 2011;469(8):2377-84.

29. Steeper LTS = more
risky ????

30. 10/12/2014

32. lateral tibial slope in steeper than the medial which could
be a major risk factor regardless of the gender

33. No difference in our study

34. Does Gender matter ???
Jiang CC, Yip KM, Liu TK. Journal of the
Formosan Medical Association Taiwan yi
zhi. 1994;93(6):509-12. Epub 1994/06/01.
• increased PTS ( 12°) was
present in female patients with
knee arthrosis as compared
with a negative group of
female patients with patella
femoral pain syndrome ( 10°
of PTS ) and male patients
with knee arthrosis ( 9° of
PTS )
• But no relation between ACL
status and slope was asessed

37. What about the meniscal slope ?

39. Limitations
• Retrospective
analysis
• Mode of injury
??
• BMI ??

40. Strength
MRI
Excellent observer
reliability
Large sample size

41. CRUX
• No difference in posterior tibial slope between
ACL intact and deficient population
• No gender difference
• Normal range of tibial slope in indian population
5°to 8°

42. Thank you …