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