Post on 16-Dec-2015
ACL DEBATE
Chad J. Micucci, MD & Gregory J. Purnell, MDOrthopedic Research of Virginia
May 2010
Overview
Introduction The Issues With ACL Injuries Anatomic ACL Reconstruction Graft Selection Discussion
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
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)
Anatomy
Extension FlexionAM
PLAM PL
Femoral and Tibial Insertions
AM
PL
AM Bundle
PL Bundle
AM and PL bundle have different length and diameter
38.5 (+/-3) 19.7 (+/-2)
AMPL
7.0 mm6.4 mm
AM
PL
Natural History
True natural history will probably never be knownMost 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 yrsJones, Injury Clinic, 2003
Most commonly via non-contact mechanism (70-80% of ACL injuries)
Sports: football, basketball, soccer Classic mechanism
Valgus, ER, twisting injury during deceleration
Epidemiology150,000 new injuries per yearIn given sport, females have 4-8 higher risk
Pathogenesis
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
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
Four categories: Environmental
○ 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)
Pathophysiology
HistoryVery important!MechanismEffusion
ExamEffusion, joint line tenderness, ROMLigamentous exam (Lachman’s)KT 1000 (quantify laxity)
Diagnosis
X-raysAP, Lateral, Merchant
Radiologic studies
MRI High sensitivity and
specificity for ACL tears
Overall accuracy approx. 95%
Not mandatory for surgical intervention
However, important for documenting associated injuries
Grading ACL injuriesI up to 5 mmII 6-10 mmIII 11-15 mmIV > 15 mm
Also note “firm” or “soft” end-point
Classification
Non-operativeUsually based on lifestyleRehabilitation
○ Quad/Hamstring strengthening
OperativeArthroscopic reconstruction
Graft SelectionBTBHamstringsAllograft
Treatment
ACL Reconstruction
Goals of ACL surgery
Provide stable joint** Delay osteoarthrosis Avoid further internal
derangement Return to sport, work,
recreational activities**
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
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 reconstructionFithian et al, Am J Sports Med,
2005
In Vivo: Abnormal Rotational Knee Motion During Running After ACL Reconstruction
Tashman, AJSM, 2004Using high speed
stereoradiographic system
AP stability restored in ACL reconstruction
Rotatory instability persisted
May contribute to long-term degeneration
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)
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
Femoral Tunnel12
9
12
9
Loh, et al, Arthroscopy, 2003
SO NOW WHAT????
WHICH GRAFT SHOULD I CHOOSE??
IS ONE GRAFT BETTER???
Your patient has already researched it on the INTERNET!!!!
Photos: Christina Allen, AAOS
Patellar tendon
Graft Selection
Hamstring tendons
Goals of surgery
Limit complications
Restore function
What is the # 1 question on this athletes’ mind???
When can I come back and play, Doc?
BONE-TENDON-BONE (BTB)ORPATELLAR TENDON (PT)
Hamstrings
INFERIOR
Hamstring reconstructions:
1. Longer time to graft incorportation
2. Grafts loosen/Tibial fixation
3. Residual flexion weakness
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
Failure of Osteointegration of Hamstring Tendon Autograft After Anterior Cruciate Ligament Reconstruction Eun Kyoo Song, M.D., et al. 2004 Arthroscopy
Report on 2 cases of failed osteointegration between the hamstring tendon and bone
Concluded failed fixation methods
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
Graft Fixation
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]
Restoration of function
“…Patellar tendon autografts had significantly lower rate of failure and resulted in better knee stability and increased patient satisfaction…”
JOURNAL
2003
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]
Hamstring Regeneration
Knee Surg Sports Traumatol Arthrosc. 2006 Jun;14(6):542-5
Knee Surg Sports Traumatol Arthrosc. 2007 Feb;15(2):153-60 (Review)
Show regeneration of hamstrings both grossly and macroscopically (“closely resembles” normal tendon)……just like “hyaline-like” cartilage!!!!
Hamstrings Regenerate???
Really!?! With Seth and Amy on ACL graft selection
Hamstring use in ACL surgeryBurks 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.
More WEAKness… Evaluation of Active Knee Flexion and Hamstring
Strength After Anterior Cruciate Ligament Reconstruction Using Hamstring Tendons Norimasa Nakamura, M.D., et al. 2002 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
What He’s Going to tell you…
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
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.
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
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.
How often do you kneel on a daily basis???
Plumber Wrestler Construction ……….
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
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 harvest2 patella fx (1 intra-op, 1 post-op); 1 patellar
tendon rupture remains a safe and viable choice
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
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.
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
HAMSTRINGS
BTB
WINNER
Thank you for playing……. Here is your parting gift from our
WINNER……
HAMSTRING GRAFT
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
Complications of BTB grafts
Anterior knee pain Loss of extension Degenerative joint disease Extensor mechanism disruption
Medscape
Anterior knee painSpindler, 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 knees@2 yrs Ejerhed AJSM 2003
50% @ 7 yrs Roe AJSM 2005
Avoiding Mismatch in Allograft Anterior Cruciate LigamentReconstruction: Correlation Between Patient Height andPatellar Tendon Length
Bach et al. Arthroscopy 2010
Femoral recession Graft rotation Hybrid fixation
Extensor mechanism disruptions
3 acute complications related to patellar tendon harvest2 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
Technical NoteManagement of Patella Fractures Associated With CentralThird Bone-Patella Tendon-Bone Autograft ACLReconstructionsEugene E. Berg, M.D.
Arthroscopy: The Journal of Arthroscopic and Related Surgery. Vol 12, No 6 1996: 756-759
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
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.
Graft loosening?
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
The truth…
Fixation method, not graft type, cause of slippage
The Incision
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
What would you want for your daughter????
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
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.
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.
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.
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
Regardless…………..Educate Factors Affecting Patient Selection of
Graft Type in Anterior Cruciate Ligament ReconstructionCohen 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
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)
Where do you want to go?
Thank You