1. Stress-radiography of the knee Anterior and posterior translation at 20° of flexion in 563 normal knees and 487 ACL deficient knees
JL. LERAT, JL. BESSE, F. CHOTEL, F. CLADIERE, B. MOYEN
Department of Orthopaedic Surgery and Sports Medicine
Lyon – France
ESSKA, Nice,
EFORT, Bruxelles 3-8 June 1999

2. Aims of the study The measurements of anterior and posterior laxity
in normal knees
and in ACL deficient knees
Diagnosis value
Grading the knee play in order to choose adaptated surgery

3. Anterior stress-radiography
Flexion : 90°
Nyga : 1970
Kennedy, Fowler : 1971
Lerat : 1971
Jacobsen : 1976

4. Anterior stress-radiography
TORG introduced the
"LACHMAN test"
in 1976
Test practised since 1963 by
TRILLAT in Lyon-France

5. Anterior stress-radiography
Manualy
20° of flexion
Lerat (manually) : 1979
Lerat (apparatus) : 1982
Stäubli, Jakob : 1982
Hooper : 1986
Iversen : 1988 l
apparatus
apparatus

6. Anterior and posterior stress-radiography
The same apparatus is used for both anterior and posterior tests
20° of flexion
Fixed load (9 kg)
Free translation
Free rotation
Comfortable for the patients

7. Anterior translation of the tibia
Posterior tibial cortex
as reference line
Parallels tangent to the posterior aspect of the condyles
Distance between these tangent lines and the
tibial compartments
ATMC: Anterior Translation of Medial Compartment
ATLC : Anterior Translation of Lateral Compartment

8. Lateral condyle : anterior notch and posterior angle
Landmarks
Lateral condyle : anterior notch and posterior angle

9. ATMC

10. ATLC

11. Anterior radiological drawer
ATMC and ATLC

12. Posterior translation of the tibia
PTMC = Posterior Translation of Medial Compartment
PTLC = Posterior Translation of Lateral Compartment

13. Materiel 1050 knees measured age : 27.5 ± 9 years (16-50)
487 ACL insufficient knees
487 contra-lateral normal knees
76 normal subjects
age : 27.5 ± 9 years (16-50)
70.5 % males, 29.5 % females
no previous surgery
no meniscus bucket-handle

14. methods
2100 X-ray films
4200 measurements
One observer (JL L)

15. Methods Interobserver intraclass correlation
3 observers
50 patients measured
(ruptured ACL - normal knee)
Intraobserver intraclass correlation
1 observer measured 50 patients twice

16. Intra and interobserver intraclass correlation for ATMC and ATLC
All values include 95 % confidence intervals
Normal Deficient ACL
ATMC 0.91 ( ) ( )
0.97 ( ) ( )
ATLC 0.92 ( ) ( )
0.93 ( ) ( )

17. RESULTS Right-left difference Post Transl Medial Comp : 1.1 ± 0.7 mm
38 normal subjects
Ant Transl Medial Comp : 0.5 ± 0.4 mm
Ant Transl Lateral Comp : 1.2 ± 0.4 mm
Post Transl Medial Comp : 1.1 ± 0.7 mm
Post Transl Lateral Comp : 1.5 ± 1.2 mm

18. No difference between males and females
RESULTS
563 normal knees
478 ACL deficient knees
ATMC = ± 2.6
ATLC = 10.5 ± 3.5
PTMC = ± 2.9
PTLC = ± 4.1
ATMC = ± 4.3
ATLC = ± 5.1
PTMC = ± 2.9
PTLC = ± 4.1
No difference between males and females

19. RESULTS
No difference for posterior translation
(ACL ruptured or not )
Posterior position is different from the radiological "zero position"
It is the "starting position" for clinical tests and for arthrometric measurements
PTMC = ± 2.9
PTLC = ± 4.1

20. Diagnosis of ACL rupture The ATMC is the most reliable
ATLC
Cut point : 6 mm
Cut point : 11.5 mm
specificity = %
sensitivity = %
predict posit. val = 89 %
predict negat. val = 88 %
87%
79 %
85 %
82 %

21. Physiological ant-post laxity
Medial
Compartment
PTMC +ATMC
4.2 ± 2.7 mm
Lateral
Compartiment
PTLC +ATLC
12.2 ± 4.5 mm

22. Pathological ant-post laxity
Medial
Compartment
PTMC +ATMC
12.1 ± 4.5 mm
Lateral
Compartiment
PTLC +ATLC
19.4 ± 5.5 mm

23. Considering differential laxity
Pathological ATMC and ATLC Normal contralateral knee

24. ACL deficient knees : differential ant. translation
ATMC
8.1 ± 4.2 mm
ATLC
7.5 ± 4.6 mm

25. Anterior laxities classification
Translation of the lateral side can be predominent
internal tibial rotation
Translation of the medial side
can be predominent
external tibial rotation

26. Anterior laxities classification
Cases
number %
ATMC

27. Anterior laxities : grade 1
Diff. Laxity mm 15 11 8 5
zero position line

28. Anterior laxities : grade 1
Diff. Laxity
ATMC 15 11 8 5
128
knees
zero position line

29. Anterior laxities : grade 1
Diff. Laxity
ATMC
ATLC 15
1 D
1 C
1 B
1 A 11 8 5 59
128
zero position line

30. Anterior laxities : grade 1
Diff. Laxity
ATMC
ATLC 15
1 D
1 C
1 B
1 A 11 8 36 5 59
128
zero position line

31. Anterior laxities : grade 1
Diff. Laxity
ATMC
ATLC 15
1 D
1 C
1 B
1 A 11 22 8 36 5 59
128
zero position line

32. Anterior laxities : grade 1
Diff. Laxity
ATMC
ATLC 15 11
1 D
1 C
1 B
1 A 11 22 8 36 5 59
128
zero position line

33. Anterior laxity : grade 2
Diff. Laxity
ATMC
ATLC 15 18
2 D
2 C
2 B
2 A 11 25 8
116 25 5 48
Zero position line

34. Anterior laxity : grade 3
ATMC
ATLC
Diff. Laxity 15 29
3 D
3 C
3 B
3 A 11
109 26 8 19 5 35
Zero position line

35. Anterior laxity : grade 4
ATMC
ATLC
Diff. Laxity 15 91
4 D
4 C
4 B
4 A 11 8 19 5 11
zero position line

36. Anterior laxity : grade 4
ATMC
ATLC
Diff. Laxity 15 91 24
4 D
4 C
4 B
4 A 11 37 8 19 5 11
zero position line

37. Anterior laxities classification
Grade 4
Grade 3
Grade 2
Grade 1
ATMC (first number) : 4 grades
ATLC (A, B, C or D) : 4 grades

38. Anterior laxities classification
Number of cases for all categories ( % )
Grade 4
Grade 3
Grade 2
Grade 1
n = 487
A B C D

39. ACL + extra-articular lateral reconstruction
Prospective surgery
ACL + extra-articular lateral reconstruction
isolated ACL

40. ACL + extra articular lateral reconstruction
Prospective surgery
ACL + medial
ACL + medial + lateral
19 %
26 %
38 %
17 %
isolated ACL
ACL + extra articular lateral reconstruction

41. Precice and objective measurement of preop and post-op laxity
Preoperative ATMC and ATLC Post op 10 years

42. "Mac InJones » procedure
ACL reconstruction with patellar tendon
Quadricipital tendon is stretched from the condyle to the Gerdy’s tubercule with solid sutures

43. Evolution of radiological laxity after surgery
ACL reconstruction + lateral plasty : 100 cases
Differential left/right laxity
Gain for ATMC : 62 % Gain for ATLC : 77 %

44. In the same way, a prospective study is started to evaluate postero-medial reconstruction

45. Conclusions Conclusive diagnosis for ACL rupture
Better comprehension of laxity physiopathology
Laxities classification
Judicious surgical treatment adaptated to the lesions

46. THANK YOU

47. Medial laxity : what i do ?

48. 1/Tensioning of distal insertion

49. 2/ Tensioning of proximal insertion

50. 3/ Tension without detaching the distal and proximal insertions using semi tendinosus or quadricipital tendon

51. 3/ Tension without detaching the distal and proximal insertions