Chad J. Micucci, MD & Gregory J. Purnell, MD
Orthopedic 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
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)
Femoral and Tibial Insertions
AM Bundle
PL Bundle
Flexion
Extension
PL
AM
PL
AM
AM
PL
7.0 mm
6.4 mm
PL
AM
PL
AM
38.5 (+/-3) 19.7 (+/-2)
AM and PL bundle have different length and diameter
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
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
Associated Injuries

Meniscus tears common
 Acute, lateral: 75%
 Chronic, medial: 91%
○ Noyes, JBJS, 1980

Removal of as little as 1530%→ ↑ 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
Pathophysiology

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)
Diagnosis

History
 Very important!
 Mechanism
 Effusion

Exam
 Effusion, joint line tenderness, ROM
 Ligamentous exam (Lachman’s)
 KT 1000 (quantify laxity)
Radiologic studies

X-rays
 AP, Lateral, Merchant
MRI




High sensitivity and
specificity for ACL
tears
Overall accuracy
approx. 95%
Not mandatory for
surgical intervention
However, important
for documenting
associated injuries
Classification

Grading ACL injuries
I
 II
 III
 IV
up to 5 mm
6-10 mm
11-15 mm
> 15 mm
 Also note “firm” or “soft” end-point
Treatment

Non-operative
 Usually based on lifestyle
 Rehabilitation
○ Quad/Hamstring strengthening

Operative
 Arthroscopic reconstruction

Graft Selection
 BTB
 Hamstrings
 Allograft
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
reconstruction

 Fithian et al, Am J Sports Med,
2005
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 longterm 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 110120°
 Femoral drilling
guide through
anteromedial
accessory portal
 10 or 2 o’clock
position (right or
left knee)
 Tunnel drilled over
guide wire

Loh, et al,
Arthroscopy, 2003
12
Femoral Tunnel
9
9
12
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
Restore function
Limit complications
What is the # 1 question on this
athletes’ mind???
When can I come back and play, Doc?
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
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
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
2003
“…Patellar tendon autografts had
significantly lower rate of failure
and resulted in better knee
stability and increased patient
satisfaction…”
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 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.

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



Easier to harvest
As strong or
stronger than B-T-B
No anterior knee
pain
B-T-B



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



Easier to harvest
As strong or
stronger than B-T-B
No anterior knee
pain
B-T-B



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



Easier to harvest
As strong or
stronger than B-T-B
No anterior knee
pain
B-T-B



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 harvest
 2 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
WINNER
HAMSTRINGS
BTB
Thank you for playing…….

Here is your parting gift from our
WINNER……
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
YES
And
, they are:
- More difficult harvest
- More risky
complications
- Anterior knee pain
- Loss of ROM
- Larger incision
- No better outcomes
Complications of BTB grafts
Medscape




Anterior knee pain
Loss of extension
Degenerative joint disease
Extensor mechanism disruption
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 knees@2 yrs
50% @ 7 yrs Roe AJSM 2005
Ejerhed AJSM 2003
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

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
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 6 1996:
756-759
Reconstruction of the anterior cruciate ligament: metaanalysis 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?
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
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 tendonbone 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 tendonbone autograft: a randomized study with 10year 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
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
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