1. ACL Debate Chad J. Micucci, MD & Gregory J. Purnell, MD
Orthopedic Research of Virginia
May 2010

2. Overview Introduction The Issues With ACL Injuries
Anatomic ACL Reconstruction
Graft Selection
Discussion

3. ACL Anatomy First described by Palmer 1938 Two fiber bundles
Anteromedial (AM)
Tight in flexion
Posterolateral (PL)
Tight in extension
Based on insertion into the tibia

4. Anatomy Avg length: 32 mm (range 22-41mm)
Avg Width: 11 mm
Vascular supply: middle geniculate artery
Nerve supply: primarily post. Articular nerve
Mechanoreceptors
Ruffini end-organ receptors (stretch)
Free nerve endings (at insertion)

5. Femoral and Tibial Insertions
AM Bundle
PL Bundle
Flexion
Extension PL AM
An important concept to understand is the relative change of the ACL insertion sites throughout flexion and extension:
Extension: two bundles are parallel
Flexion: femoral insertion site of the PLB comes forward and the two bundles cross each other PL AM AM PL

6. AM and PL bundle have different length and diameter
7.0 mm
6.4 mm PL AM PL
Studies of intraarticular length
AMB significantly longer intraarticular length
However, cross-sectional diameter not too different AM
38.5 (+/-3)
19.7 (+/-2)
AM and PL bundle have different length and diameter

7. Natural History True natural history will probably never be known
Most studies look at symptomatic patients
Numerous studies have implicated the ACL deficient knee in accelerated osteoarthritis
40-70% patients have x-ray evidence of DJD at 8-10 yrs
Jones, Injury Clinic, 2003

8. Pathogenesis
Most commonly via non-contact mechanism (70-80% of ACL injuries)
Sports: football, basketball, soccer
Classic mechanism
Valgus, ER, twisting injury during deceleration
Epidemiology
150,000 new injuries per year
In given sport, females have 4-8 higher risk

9. Associated Injuries Meniscus tears common
Acute, lateral: 75%
Chronic, medial: 91%
Noyes, JBJS, 1980
Removal of as little as 15-30%→ ↑ contact forces up to 350%
Baratz, Am J Sports Med, 1986
Meniscus is a secondary stabilizer to anterior translation in ACL deficient knee

10. Bone Bruises
Middle portion of LFC; posterior portion of lateral plateau
Graf, Am J Sports Med, 1993
Significance unknown
Result of rotatory motion
Second look arthroscopy at 6 years shows cartilage thinning in areas of bruising
Clatworthy, Clin Sports Med, 1999

11. Pathophysiology Four categories: Environmental Anatomical Hormonal
Dry playing surfaces
Increased fricition between shoes and surface
Anatomical
Larger X-sect area of ACL in males
Narrower notch in females (? Significance?)
Hormonal
Conflicting data on estrogen and progesterone
Biomechanical
Differing patterns of knee motion may be associated with differences in neuromuscular control (i.e., females decrease hamstring firing, higher ant. Tibial shear force, greater knee valgus moment, smaller knee flexion angle have been noted in some studies)

12. Diagnosis History Exam Very important! Mechanism Effusion
Effusion, joint line tenderness, ROM
Ligamentous exam (Lachman’s)
KT 1000 (quantify laxity)

13. Radiologic studies
X-rays
AP, Lateral, Merchant

14. MRI High sensitivity and specificity for ACL tears
Overall accuracy approx. 95%
Not mandatory for surgical intervention
However, important for documenting associated injuries

15. Classification Grading ACL injuries I up to 5 mm II 6-10 mm
III mm
IV > 15 mm
Also note “firm” or “soft” end-point

16. Treatment Non-operative Operative Graft Selection
Usually based on lifestyle
Rehabilitation
Quad/Hamstring strengthening
Operative
Arthroscopic reconstruction
Graft Selection
BTB
Hamstrings
Allograft

17. ACL Reconstruction

18. Goals of ACL surgery Provide stable joint**
Delay osteoarthrosis
Avoid further internal derangement
Return to sport, work, recreational activities**

19. Success of the ACL surgery
Clinical success rates range from 69-95%
Yunes, Arthroscopy, 2001
Freedman, Am J Sports Med, 2003
Studies include data from experienced, fellowship trained ACL surgeons
85% of surgeons performing ACL reconstruction do fewer than 10 per year
Harner, Arthroscopy, 2004

20. Success??
Degenerative radiographic changes in 90% of patients 7 years after ACL single-bundle reconstruction
47% of patients returned to previous activity level after ACL single-bundle reconstruction
Fithian et al, Am J Sports Med, 2005

21. In Vivo: Abnormal Rotational Knee Motion During Running After ACL Reconstruction
Tashman, AJSM, 2004
Using high speed stereoradiographic system
AP stability restored in ACL reconstruction
Rotatory instability persisted
May contribute to long-term degeneration

22. Biomechanical analysis of anatomic ACL reconstruction. AJSM 2003
Fu and co-workers
Demonstrated that a non-anatomic single-bundle reconstruction is biomechanically and kinematically inferior to an anatomic reconstruction (whether it is double- or single-bundle)

23. Femoral Tunnel Knee flexed 110- 120°
Femoral drilling guide through anteromedial accessory portal
10 or 2 o’clock position (right or left knee)
Tunnel drilled over guide wire

24. Loh, et al, Arthroscopy, 2003 12 12
Femoral Tunnel 9 9

25. SO NOW WHAT???? WHICH GRAFT SHOULD I CHOOSE?? IS ONE GRAFT BETTER???
Your patient has already researched it on the INTERNET!!!!

26. Graft Selection Patellar tendon Hamstring tendons
Photos: Christina Allen, AAOS
Patellar tendon
Graft Selection
Hamstring tendons

27. Goals of surgery
Restore function
Limit complications

28. What is the # 1 question on this athletes’ mind???
When can I come back and play, Doc?

29. BONE-TENDON-BONE (BTB) OR PATELLAR TENDON (PT)

30. Hamstrings INFERIOR Hamstring reconstructions:
1. Longer time to graft incorportation
2. Grafts loosen/Tibial fixation
3. Residual flexion weakness

31. Graft Healing
Anterior Cruciate Ligament Replacement using Patellar Tendon. An evaluation of graft revascularization in the dog. Arnoczky JBJS 1982.
16 weeks showed near-completion of revascularization of the graft.
Tendon-healing in a bone tunnel: a Biomechanical and histological study in the dog. Rodeo et al. JBJS 1993.
Tendon healing to bone: 12 weeks
Bone-tendon-Bone healing: 6 weeks

32. Failure of Osteointegration of Hamstring Tendon Autograft After Anterior Cruciate Ligament Reconstruction
Eun Kyoo Song, M.D., et al Arthroscopy
Report on 2 cases of failed osteointegration between the hamstring tendon and bone
Concluded failed fixation methods

33. Graft Fixation
Inadequate fixation is the most common cause of ACL failure in the first 2 months post-op
Studies have indicated tibial fixation the weakest point in early post-op period (due to cancellous bone and screw divergence)
Most common is Interference screw fixation
Parallel fixation is crucial
Area of screw compressing bone plug or soft tissue graft important

34. Graft loosening? BTB grafts heal faster
BTB fixation better construct than SMT [Adam AJSM 2004]
BTB had lower side to side difference [Freeman AJSM 2003]
BTB have less tunnel widening [Aglietti JBJS 2004]

35. Restoration of function
2003
JOURNAL
“…Patellar tendon autografts had significantly lower rate of failure and resulted in better knee stability and increased patient satisfaction…”

36. Flexion weakness Theoretical in most activities
> 90% strength of contralateral knee [Spindler AJSM 2004]
Weakness most significant at higher degrees of flexion (>90 degrees) [Nakamura Arthroscopy 2002]
@ 18 months, 69-83% decrease in strength with 110 degrees of flexion [Tashiro AJSM 2003]

37. Hamstring Regeneration
Knee Surg Sports Traumatol Arthrosc Jun;14(6):542-5
Knee Surg Sports Traumatol Arthrosc Feb;15(2): (Review)
Show regeneration of hamstrings both grossly and macroscopically (“closely resembles” normal tendon)……just like “hyaline-like” cartilage!!!!

38. Hamstrings Regenerate???
Really!?! With Seth and Amy on ACL graft selection

39. Hamstring use in ACL surgery Burks et al. Arthroscopy 2005
Hamstring strength testing revealed a 26% deficit at 6 months, 21% at 12 months
Conclusions: At 1 year, the S.T.and gracilis muscles showed significant and persistent atrophy and frequent retraction of the S.T. muscle belly.
Hamstring strength deficits persisting at 1 year after the use of the tendons for ACL reconstruction.

40. More WEAKness…
Evaluation of Active Knee Flexion and Hamstring Strength After Anterior Cruciate Ligament Reconstruction Using Hamstring Tendons
Norimasa Nakamura, M.D., et al Arthroscopy
Isokinetic testing showed decreased strength at 90 deg flexion angle on operative side
The side-to-side ratio in mean maximum standing knee flexion angle was significantly lower in the ST/G group than in the ST group.
Conclusions: This study suggests that the loss of knee flexor strength following the harvest of the hamstring tendons may be more significant than has been previously estimated. Furthermore, multiple tendon harvest may affect the range of active knee flexion

41. What He’s Going to tell you…

42. Hamstrings B-T-B Easier to harvest As strong or stronger than B-T-B
No anterior knee pain
More difficult harvest
Anterior knee pain
Patella fractures

43. Prevalence of Saphenous Nerve Injury After Autogenous Hamstring Harvest
Brett Sanders, M.D., et al. Arthroscopy 2007
Results: Postoperative sensory disturbance was present in 74% of patients surveyed.
Conclusions: The SBSN is at higher risk of injury during hamstring ACL reconstruction than has been previously reported.

44. Hamstrings B-T-B Easier to harvest As strong or stronger than B-T-B
No anterior knee pain
More difficult harvest
Anterior knee pain
Patella fractures

45. Treatment of Anterior Cruciate Ligament Injuries With Special Reference to Graft Type and Surgical Technique: An Assessment of Randomized Controlled Trials (A systematic review)
Kristian Samuelsson, M.D., et al. Arthroscopy 2009
The BPTB graft produces more anterior knee pain and kneeling pain than the HT graft, but the difference disappears with time.

46. How often do you kneel on a daily basis???
Plumber
Wrestler
Construction
……….

47. Hamstrings B-T-B Easier to harvest As strong or stronger than B-T-B
No anterior knee pain
More difficult harvest
Anterior knee pain
Patella fractures

48. 3 fellowship-trained sports medicine surgeons
The Incidence of Acute Patellar Tendon Harvest Complications for ACL Reconstruction
Bach et al. Arthrscopy 2008
September 1986 to April 2006
1,725 consecutive patients primary ACL reconstruction using BPTB autograft
3 fellowship-trained sports medicine surgeons
3 acute complications (0.2%) related to patellar tendon harvest
2 patella fx (1 intra-op, 1 post-op); 1 patellar tendon rupture
remains a safe and viable choice

49. Outcomes
Central Third Bone–Patellar Tendon–Bone Anterior Cruciate Ligament Reconstruction: A 5-Year Follow-up
Jig V. Patel, F.R.C.S., J. Sam Church, B.S.c., M.B., B.S., and Anthony J. Hall, F.R.C.S.
All patients had knee flexion within 10 degrees of uninjured leg
Only 3 patients had clinical signs of instability on 5 yr follow up
Either + Lachman’s, pivot shift, or >3mm diff. on KT-1000

50. Outcomes
Reconstruction of the anterior cruciate ligament: meta-analysis of patellar tendon versus hamstring tendon autograft.
Goldblatt, Richmond, et al Arthroscopy 2005
Overall, incidence of instability is not significantly different between the BPTB and HT grafts.
However, BPTB was more likely to result in normal Lachman, normal pivot-shift, KT-1000 side-to-side difference < 3 mm, and fewer results with significant flexion loss.

51. Outcomes
Reconstruction of the anterior cruciate ligament in females: A comparison of hamstring versus patellar tendon autograft.
Barrett et al. Arthroscopy 2002
CONCLUSIONS: Although not statistically significant, the hamstring group had more failures, more laxity on exam, and more pts with larger KT-1000 differences. These results indicate a trend toward increased graft laxity in female patients undergoing reconstruction with hamstring autograft compared with BTB

52. WINNER
HAMSTRINGS
BTB

53. Thank you for playing…….
Here is your parting gift from our WINNER……

54. HAMSTRING GRAFT

55. What I will tell you about….
Hamstrings
YES, they are:
-stronger
-easier to harvest
-smaller incision
-no anterior knee pain
-weakness not noticeable long term
-outcomes equal
B-T-B
And YES, they are:
More difficult harvest
More risky complications
Anterior knee pain
Loss of ROM
Larger incision
No better outcomes

56. Complications of BTB grafts
Medscape
Anterior knee pain
Loss of extension
Degenerative joint disease
Extensor mechanism disruption

57. Anterior knee pain
Spindler, AJSM, 2004 “When evaluating subjective anterior knee pain or kneeling pain, the results are reproducible and clear-cut.”
Kneeling pain
50-65% BPTB unable to walk on yrs Ejerhed AJSM 2003
50% @ 7 yrs Roe AJSM 2005

58. Bach et al. Arthroscopy 2010 Femoral recession Graft rotation
Avoiding Mismatch in Allograft Anterior Cruciate Ligament Reconstruction: Correlation Between Patient Height and Patellar Tendon Length
Bach et al. Arthroscopy 2010
Femoral recession
Graft rotation
Hybrid fixation

59. Extensor mechanism disruptions
3 acute complications related to patellar tendon harvest
2 patella fx (1 intra-op, 1 post-op); 1 patellar tendon rupture
Bach et al. Arthrscopy 2008
Patellar Tendon Rupture 3 Years After Anterior Cruciate Ligament Reconstruction With a Central One Third Bone–Patellar Tendon–Bone Graft
Phillip L. Mickelsen, M.D., et al. Arthroscopy 2001

60. Technical Note Management of Patella Fractures Associated With CentralThird Bone-Patella Tendon-Bone Autograft ACLReconstructions Eugene E. Berg, M.D.
Arthroscopy: The Journal of Arthroscopic and Related Surgery. Vol 12, No :

62. Reconstruction of the anterior cruciate ligament: meta-analysis of patellar tendon versus hamstring tendon autograft
Goldblatt, Richmond, et al Arthroscopy 2005
HT grafts had a reduced incidence of patellofemoral crepitance, kneeling pain, and extension loss

63. What healing problems???
Comparison of Clinical Results and Second-Look Arthroscopy Findings After Arthroscopic Anterior Cruciate Ligament
Reconstruction Using 3 Different Types of Grafts
Jung Hwan Lee, M.D., et al. Arthroscopy 2010
Hamstring autograft group better synovial coverage on second-look arthroscopy
Better synovial coverage on second-look arthroscopy presented better clinical results on the IKDC objective examination form.

64. Graft loosening? Fixation method, not graft type, cause of slippage
The truth…
PT tendons heal faster
Transfixation better than interference for hamstring grafts??? Ahmad AJSM 2004
Tranfixation of STG may be better than interference PT Rowden AJSM 1997
Fixation method, not graft type, cause of slippage

65. The Incision

66. Hamstring strength NOT an issue
GRAFT
TENSILE LOAD (N)
STIFFNESS (N/mm)
CROSS SECTIONAL AREA (mm2)
Native ACL
2160
242 44
Patellar Tendon Autograft
2977
620 35
Quadrupled Hamstrings
4090
776 53
West and Harner JAAOS 2005

67. What would you want for your daughter????

68. Outcomes
Anterior cruciate ligament reconstruction, hamstring versus bone-patella tendon-bone grafts: a systematic literature review of outcome from surgery.
Herrington, et al. Knee 2005
The results of the 13 studies included in this review suggest that there is no significant evidence to indicate that one graft is superior. Both the PT and HT grafts appear to improve patients' performance, and therefore both would be good choices for ACL reconstruction

69. Outcomes
Patellar tendon or four-strand hamstring? A systematic review of autografts for anterior cruciate ligament reconstruction
Forster, et al. Knee 2005
Overall, there was a greater chance of extension loss (p=0.007) and a trend towards increased PFJ pain (p=0.09) with BTB
There was no difference with Lachman testing, chance of returning to the same level of sport, clinical knee scores, graft ruptures or other complications.

70. Outcomes
A prospective, randomized comparison of semitendinosus and gracilis tendon versus patellar tendon autografts for anterior cruciate ligament reconstruction: five-year follow-up
Sajovic, et al. AJSM 2006
CONCLUSION: Both provided good subjective outcomes and objective stability at 5 years.
No significant differences in the rate of graft failure were identified.
Patients with patellar tendon grafts had a greater prevalence of osteoarthritis at 5 years after surgery.

71. Outcomes
Hamstring tendon versus patellar tendon anterior cruciate ligament reconstruction using biodegradable interference fit fixation: a prospective matched-group analysis.
Wagner et al. AJSM 2004
Hamstring tendon graft was superior in knee stability and function. These findings are partially contrary to previous studies and might be attributable to the use of an anatomical joint line fixation for hamstring tendon grafts.

72. Outcomes
No difference in knee function or prevalence of osteoarthritis after reconstruction of the anterior cruciate ligament with 4-strand hamstring autograft versus patellar tendon-bone autograft: a randomized study with 10-year follow-up
Homi et al. AJSM 2010
No statistically significant differences in clinical outcome at 10 years
Prevalence of OA significantly higher in operated leg
No significant differences between the 2 groups

73. Regardless…………..Educate
Factors Affecting Patient Selection of Graft Type in Anterior Cruciate Ligament Reconstruction
Cohen et al. Arthroscopy 2009
Most important factor for a patient choosing a graft for ACL reconstruction is physician recommendation
Increasing trend toward the use of allograft materials for ACL reconstruction
63.3% of all graft materials selected

74. J. Richmond. AANA 2010 Author’s Current Surgical Treatment Algorithm
“High demand”: eg. Competitive athlete
 Autologous B-PT-B
“Moderate demand”: eg. Recreational athlete
 Autologous Q-ST&G
“Lower demand” or other modifying
circumstance (age, autologous tendon
issues, revision)
 Allograft (tibialis or B-PT-B)

75. Where do you want to go?

76. Thank You