1. 6th Annual Wichita Sports Medicine Symposium
June 6th 2009

2. KNEE LIGAMENT INJURIES: EXAM AND TREATMENT
Daniel J. Prohaska, MD
June 6, 2009

3. Talk available:

4. Knee Ligaments Why do we need a knee lecture
Everything is pretty much sorted out in regard to the knee isn’t it?
Just when you think you have it all down….

5. It's not just the ACL

6. It's the whole knee
Cartilage
Insertion site
Graft healing
Meniscus
Neurovascular
ingrowth
bone
Muscle

7. ACL 48% MCL 29% ACL/MCL 13% PCL 7% LCL 3% Ligament Injury
Miyasaka, 1989

8. 200,000 ACL Injuries Per Year?

9. Different Grafts Biological graft materials:
autograft: BPTB, Hamstrings, Quad-tendon
allograft: Achilles, BPTB, ACL, peroneal
Synthetic graft materials have not been successful
Engineered biological ACL scaffolds:
still experimental

10. Use of different grafts
BPTB
1983- Extraarticular
Allografts
BPTB-Auto
1992- Hamstrings

11. Who Uses What? Hamstrings + BPTB: equal. 62% use multiple grafts
Education of graft choices leads to best graft
More than one graft may work for each patient

12. Global Perspective on ACL Reconstruction
> 20 different techniques
> 5 different grafts
different rehab protocols
different outcome assessments
overall clinical / functional results
are good or excellent

13. How perfect are current
operative techniques?
Need for improvement?

14. 20 years ago less knowledge
about graft options

15. Graft Comparison Advantages Disadvantages BPTB
Consistent size and shape
Bone to bone healing
Consistent fixation
Donor site morbidity
HAMSTRINGS
Various fixations
Tendon-Bone-Healing
Greater stiffness
No interference with extensor mechanism

16. Graft Comparison Advantages Disadvantages Quadriceps tendon
Higher stiffness
Bone to bone healing at one side
Donor site morbidity
Allograft
Decrease in tensile strength
Prolonged healing response
Disease transmission
Better cosmesis
No donor site morbidity
Less postoperative pain

17. Does not yet exist Perfect Graft Reproduces insertion and biomechanics
Biological incorporation
Resumes neuromuscular control
Does not yet exist

18. Biomechanical research
Single bundle ACL (BPTB and hamstrings)
AP stability restored
rotational stability not restored
Pivot shift not restored

19. Where we are:
Development of Reconstructive Knee Surgery has made advancements largely due to the use of the arthroscope.
Patients and physicians now take for granted that procedures can be done with arthroscopic assist.

20. Literature
Suggests it is possible to obtain stability 90-95% with variety of graft sources
Not all surgeons can obtain this level of stability with single tunnel technique
Doing a double bundle does not make the procedure technically easier and may in fact lead to further instability ?

21. Are WeFailing Our patients
Changes in ACL surgery/rehab need to focus on where we are failing patients
Are we failing with the single tunnel technique?

22. Where are we failing?
Recent studies have found that patients with ACL reconstruction have a high incidence of arthritic changes in the long-term
We want to prevent arthritic changes, but do we really know why they occur?

23. Where are we failing?
Is it the meniscus, bone bruise, the cartilage, the graft?
Do we need double bundles?
The theory is that arthritic changes are occuring because adequate stability is not being achieved with single-bundle

24. Where are we failing?
ACL deficient knee alone does not cause arthritic changes
It is the meniscus tears and chondral damage that occurs with additional giving way episodes that causes the problem
If a person with an ACL-deficient knee can prevent instability, arthritic changes may not occur

25. Where are we failing?
Patients who have some knee laxity with full ROM are better off long-term than patients with stability and less than full ROM
“Stable” knees may be bad knees in the future if we don’t also consider all factors that make knees symmetrical

26. Where are we failing?
Goals of ACL surgery is to obtain knee symmetry for
Stability
ROM
Strength
FUNCTION

27. Don’t change into a technicians
We seem to always seek a surgical answer to problems
Most solvable problems are related to rehabilitation, not surgery
Cannot control meniscus tears or chondral damage

28. Changing Surgical Technique
Why “fix” a problem that we have not really found
Why Ignore other big problems, ie chondral and meniscus damage

29. Biomechanical Research
need for
in situ forces
in vivo data
For ACL and PCL !

30. ACL Single bundle ACL currently the gold standard
10-35% poor results based on continued pain and instability
Long term follow-up (7 years) shows indicates a high proportion of patients develop DJD
Biau, Corr, 2007
Freedman et al.,AJSM, 2003
Fithian DC et al, AJSM 2005

31. Single Bundle ACL
Single bundle ACL reconstruction does not recreate the normal knee kinematics
Evidence points to double bundle recreating kinematics
Does it matter?

32. ACL Anatomy
PL and AM parallel in extension
Both bundles have tension

33. ACL Anatomy
In flexion AM stays tight, PL loosens

34. ACL
Histologically the insertions are distinct

35. ACL Right knee Standard lateral portal
Only bifurcate ridge and part of posterolateral bundle insertion are visualized

36. ACL Anatomy
Right Knee
Viewing through medial portal

37. ACL Anatomy

38. 3-D ACL reconstruction Tunnel

39. 3-D ACL reconstruction Tunnel

41. $
ACL Factory?

42. ? ACL double-bundle What does it take to do double? ACL graft:
2 bundles
What does it take to do double?

43. PCL injuries treatment controversial conservative treatment
for isolated injuries ?
clinical results of PCL reconstruction:
80% satisfaction

44. PCL Anatomy - Components
anterolateral (AL)
taut in flexion
posteromedial (PM)
taut in extension
meniscofemoral (MFL)

45. PCL Biomechanics
Tensile testing: AL - stiffer, stronger than PM and MFL
Function of different bundles of PCL can not be restored with single drill hole replacement

46. PCL Reconstruction 1999 Current approaches tunnel placement: AL
graft fixation / tension: knee in flexion
Newer considerations
double bundle

47. PCL Reconstruction – 2009 Double Bundle 1. AL 10 mm Achilles tendon
Fix at 90° with anterior drawer
2. PM
7-8 mm doubled ST
Fix at full extension

48. PCL Reconstruction
Double-bundle technique AL PM

49. PCL Reconstruction
Tibial Onlay technique

50. GRAFT HEALING
Goal is to reproduce the insertion site of the native ACL
Different healing for different grafts

51. ACL insertion bone mineralized cartilage non-mineralized ligament
subchondral bone
mineralized cartilage
non-mineralized cartilage
ligament
“tide mark”
mineralized
cartilage
non-mineralized
bone
ligament

52. Animal studies for tendon to bone fixation (hamstring)
Sharpey's fibers
Single collagen fibers
attaching to bone
Rodeo et al, 1993
Extra-articular model
Intra-articular model
Grana et al. 1994

53. Factor of Rehabilitation
Tailor Made !
Rehab depending on graft fixation
slow
rehabilitation
fast

54. Different Fixations

55. Fixation with bioscrew
But ...
Weiler et al. 1998

56. Fixation - Failures single side fixation FAILED HEALING ?
ACL reconstruction with hamstrings,
fixation with PLLA interference screw
15 mo after ACL surgery
single side fixation
FAILED HEALING ?

57. Fixation - Failures New Bio-Screws with TCP to incorporate faster
Allograft Screws: $$$$
Two screws more than surgeon reimbursement for procedure
Billed to insurance as allograft: ethics of this practice?

58. Biological Incorporation
No graft can completely reproduce insertion sites!
Improve healing?
Improve remodeling?

59. Biological solutions
Decorin
BMP-2
IGF-1
bFGF
NEAR FUTURE ?

60. Immobilization Not the answer to gain graft incorporation.
Graft incorporation enhanced by stress loads below the threshold of fixation

61. Problems with Motion Post Op
Some reasons patients have problems with extension post op could be cyclops lesion, scar tissue, or malposition of graft. Surgeon needs to be sure of graft placement and check motion before secures the graft in place

62. Scar tissue
Scar tissue around the patella femoral joint will severely limit flexion. This needs to be addressed early in PT with aggressive treatment for patellar mobilization.
Stiffness rate should not exceed 3-5%.

63. Biological solutions
Cell therapy
Gene therapy
Tissue engineering

64. GENE THERAPY

65. Why Improve? Too Much Morbidity from injuries and the surgery!
Preventive Training unable to prevent injury.

66. What can we do to become better?
Understand anatomy
Recreate anatomy as closely as possible
Use of technology?
Need for more accurate way to measure reproducibly rotational control achieved with ACL reconstructions

67. Thank You!!