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THE LARS AUGMENTED 4-TUNNEL HAMSTRING "hYBRID" ACLR GRAFT CONSTRUCTION ALLOWS ACCELERATED REHABILITATION WITHOUT KNEE LAXITY - CASE SERIES of 111 PATIENTS after 2 YEARS

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  • Perth Orthopaedic and Sports Medicine Centre, Perth ,Western Australia
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THE LARS AUGMENTED 4-TUNNEL HAMSTRING "hYBRID" ACLR GRAFT CONSTRUCTION ALLOWS ACCELERATED REHABILITATION WITHOUT KNEE LAXITY - CASE SERIES of 111 PATIENTS after 2 YEARS

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Purpose: This prospective case series is designed to determine the 2-year clinical and radiological outcomes of patients undergoing an ACL reconstruction using the ligament augmentation reconstruction system (LARS) 133 prosthesis as an augmentation device for a 4-tunnel autologous hamstrings graft, in the context of accelerated rehabilitation. Methods: A total of 91 patients were assessed at 2 years post-operatively after undergoing an anterior cruciate ligament reconstruction (ACLR) with a doubled semitendinosis and LARS 133 prosthesis for the anteromedial bundle (AMB) and gracilis for the posterolateral bundle. Assessment included clinical review, KT-1000 arthrometry, IKDC, Tegner, Lysholm, Cincinnati and ACL QOL knee scoring, graft failure and re-operation rates. Tunnel positions and synovitis were assessed using gadolinium magnetic resonance imaging (MRI) scans and X-rays. Results: This technique in the context of accelerated rehabilitation is not associated with increased knee laxity and failure. There was no increase in knee laxity, with a mean side-to-side difference in KT-1000 arthrometer testing of 0.5mm (+/− 1.7). Two-year outcomes were satisfactory with 98% of all patients having an IKDC rating of A or B, and mean values of IKDC subjective 86.5 (+/− 11.6), Tegner 6.5 (+/− 2.0), Lysholm 87.1 (+/− 8.9), Cincinnati 378.8 (+/− 41.5) and ACL Quality of Life 81.5 (+/− 19.3). There was no evidence of synovitis and all tunnels were positioned satisfactorily. The graft failure rate was 1.1% and there was a re-operation rate of 15.4%. Conclusion: We conclude that LARS 133 augmentation of autologous hamstrings ACLR provides a graft construct allowing accelerated rehabilitation without increased knee laxity. It is not associated with significant synovitis within the first two years. Re-operation rates however are higher. The rates at which patients recover and return to life and sports activity following different ACLR graft types appears as a topic of future research interest.
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THE LARS AUGMENTED 4-TUNNEL HAMSTRING HYBRID
ACLR GRAFT CONSTRUCTION ALLOWS ACCELERATED
REHABILITATION WITHOUT KNEE LAXITY |
|
|CASE SERIES
OF 111 PATIENTS AFTER 2 YEARS
Travis M. Falconer
Perth Orthopaedic & Sports Medicine Center
31 Outram Street, West Perth
Western Australia 6005
Department of Orthopaedic Surgery, Sir Charles Gairdner Hospital
Hospital Ave, Nedlands WA 6009, Australia
travis.falconer@perthortho.com.au
Louise Tusak
31 Outram Street, West Perth
Western Australia 6005
William H. Breidahl
Perth Radiological Clinic, 127 Hamersley Rd
Subiaco WA 6008, Australia
Department of Radiology, Royal Perth Hospital
197 Wellington St, Perth WA 6000, Australia
Peter T. Annear
Perth Orthopaedic & Sports Medicine Center
31 Outram Street, West Perth
Western Australia 6005
Department of Orthopaedic Surgery, Princess Margaret Hospital
610 University Ave, Toronto, ON M5G 2M9, Canada
Correspondence to: Dr. Travis M. Falconer, Perth Orthopaedic & Sports Medicine Center, 31 Outram Street, West Perth,
Western Australia 6005.
Journal of Musculoskeletal Research, Vol. 18, No. 4 (2015) 1550020 (15 pages)
© World Scientic Publishing Company
DOI: 10.1142/S0218957715500207
1550020-1
J. Musculoskelet. Res. 2015.18. Downloaded from www.worldscientific.com
by Mr. Reprints Desk on 07/12/16. For personal use only.
Received 2 October 2015
Revised 26 March 2016
Accepted 20 April 2016
Published 27 May 2016
ABSTRACT
Purpose: This prospective case series is designed to determine the 2-year clinical and radiological
outcomes of patients undergoing an ACL reconstruction using the ligament augmentation recon-
struction system (LARS) 133 prosthesis as an augmentation device for a 4-tunnel autologous ham-
strings graft, in the context of accelerated rehabilitation. Methods: A total of 91 patients were assessed
at 2 years post-operatively after undergoing an anterior cruciate ligament reconstruction (ACLR) with
a doubled semitendinosis and LARS 133 prosthesis for the anteromedial bundle (AMB) and gracilis for
the posterolateral bundle. Assessment included clinical review, KT-1000 arthrometry, IKDC, Tegner,
Lysholm, Cincinnati and ACL QOL knee scoring, graft failure and re-operation rates. Tunnel positions
and synovitis were assessed using gadolinium magnetic resonance imaging (MRI) scans and X-rays.
Results: This technique in the context of accelerated rehabilitation is not associated with increased
knee laxity and failure. There was no increase in knee laxity, with a mean side-to-side difference in KT-
1000 arthrometer testing of 0.5 mm (þ/1.7). Two-year outcomes were satisfactory with 98% of all
patients having an IKDC rating of A or B, and mean values of IKDC subjective 86.5 (þ/11.6), Tegner
6.5 (þ/2.0), Lysholm 87.1 (þ/8.9), Cincinnati 378.8 (þ/41.5) and ACL Quality of Life 81.5 (þ/
19.3). There was no evidence of synovitis and all tunnels were positioned satisfactorily. The graft
failure rate was 1.1% and there was a re-operation rate of 15.4%. Conclusion: We conclude that LARS
133 augmentation of autologous hamstrings ACLR provides a graft construct allowing accelerated
rehabilitation without increased knee laxity. It is not associated with signicant synovitis within the
rst two years. Re-operation rates however are higher. The rates at which patients recover and return
to life and sports activity following different ACLR graft types appears as a topic of future research
interest.
Keywords: Synthetic grafts; Anterior cruciate ligament; Anatomical ACL.
INTRODUCTION
Anterior cruciate ligament reconstruction (ACLR)
predictably improves anterior cruciate ligament
(ACL) decient patients knee stability and
function.
20,28
Considerable time may be needed
to return to physical work and sport (jogging at 4
months, sport 12 months) after the surgery. Ear-
lier return to occupational and sport activities
following ACLR would appear desirable for the
patient both nancially and from a recreational
viewpoint.
Decreased ACL graft strength and stiffness
occurs during the autograft and allograft graft re-
vascularization phase of healing,
4,6,35
necessitating
low load rehabilitation in the rst 34 months post-
surgery. Accelerated rehabilitation in hamstring
autograft ACLR (jogging at 2 months) leads to
graft laxity
7,13,21,31
and high re-rupture rates.
Replacing the ruptured ACL with a synthetic
prosthetic ligament to bypass this problem has led
to high re-rupture rates, signicant synovitis and
catastrophic failures.
16,17,19,23,29,30,36,37
Previous
attempts to accelerate rehabilitation using the
ligament augmentation device (LAD),
18
apoly-
propylene braided prosthesis, were abandoned
due to increased rates of failure and synovitis.
17
Adding a smaller articial ligament to an autograft
has been performed to allow early weight bearing
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and knee motion
18,19,26
or to augment a small or
failed graft harvest.
11
It is unknown however
whether this prosthetic autograft combination or
hybridgraft could safely speed recovery time
post ACLR. Interestingly the ACLR literature
(studying both prosthetic and autograft recon-
structions alike) rarely reports the actual time
patients take to recover from ACLR and to our
knowledge no validated scores have been devel-
oped to measure this. Finally, it is unknown if this
graft construct will provide satisfactory long-term
results.
The aim of this study is to perform hybrid
graft ACLR using hamstrings autograft and a
new prosthetic ligament (LARSLigament Aug-
mentation Reconstruction System, Corin Pty.
Ltd.) and safely accelerate the rehabilitation (jog 2
months and sport 6 months). The 2-year results
would be important to assess for increased knee
laxity, failure and specic complications from the
prosthetic component of the graft.
We hypothesize that using an augmented au-
tologous hamstrings graft rehabilitation can be
safely accelerated without increased knee laxity,
failure or adverse outcomes. Furthermore, we
consider that the newer generation augmentation
devices coupled with the correct surgical tech-
nique may not cause the high graft failures, sy-
novitis and intra-articular reactions that have
historically been seen.
MATERIALS AND METHODS
A total of 111 consecutive consenting patients
between March 2009 and April 2010 undergoing
acute primary ACLR were recruited to this pro-
spective single surgeon case series with institu-
tional ethics committee approval. Inclusion
criteria were patients with a primary ACL de-
cient knee not requiring concomitant ligament or
meniscal repair surgery, skeletal maturity, a
normal contralateral knee, normal limb
alignment and with index surgery within six
months of injury. Compensable work or accident
related knee injuries were excluded. All eligible
patients were offered either a hamstring autograft
with standard rehabilitation or a hybrid graft
with accelerated rehabilitation. Patients selecting
a hybrid graft were included in the study. Their
ow through the study and numbers included for
analysis are shown in Fig. 1.
The Graft Construct
The hybrid graftconstruct consists of a small
LARS prosthetic ligament (Corin Group Product
Code 104.133 LARS anterior cruciate rein-
forcement) added alongside the semitendinosus
tendon of the anteromedial bundle (AMB) graft
in an otherwise standard 4-tunnel double bundle
hamstring ACLR. The aim of adding the pros-
thesis to the hamstrings was to stiffen the graft.
The aim of combining the hamstrings to the
prosthesis was to ensure graft longevity and
protect the knee from particulate wear. The AMB
was chosen for augmentation as this bundle was
considered most important under accelerated re-
habilitation loads. The posterolateral bundle
(PLB) graft consisted of double gracilis tendon.
Surgical Technique
A double bundle anatomical technique was used
with two tunnels on the tibia and two tunnels on
the femur. Ipsilateral semitendinosus and gracilis
were routinely harvested from the injured leg
and prepared. The AMB augmentation involved
doubling the LARS 133 ligament through the
same 20 mm Endobutton loop (Smith & Nephew
Pty. Ltd.) as the doubled semitendinosus tendon.
The LARS ligament was not sutured to the ten-
don. The prosthesis added 1 mm to the AMB
graft tunnel diameter and 9 mm
2
to the cross-
sectional area. The prepared hybrid graft
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construct is displayed in Fig. 2. The PLB was
reconstructed using doubled gracilis over a
20 mm Endobutton loop. The femoral tunnel
positions were based on the patientsresidual
footprint anatomy. If absent, the AMB was
marked 5 mm off the posterior notch wall at 1:30
oclock (left knee) with the knee at 90exion.
The PLB was marked at a line 30below the
femur axis 8 mm distal and posterior to the AMB
mark, 5 mm short of the articular surface. These
awl marks are displayed in Fig. 3. The AMB
tibial tunnel was placed central to the tibial
remnant 8 mm using the ACL director drill
guide, elbow aimer and bullet guide (Smith and
Nephew Pty. Ltd, product codes 72205517,
72205518 and 72205525) placed 8 mm from the
anterior tibial stump margin as demonstrated in
Fig. 4. The ACL aiming device was placed
Assessment of
eligibility
213 total patients
Within a single private practice undergoing
primary ACL reconstruction
between March 2009 & April 2010
111 patients consented to autologous
hamstrings & LARS 133 hybrid surgery
92 patients declined to participate
& received other graft choices
83 received autologous
double bundle hamstrings
reconstruction
9 received LARS only as
a graft choice
Allocation
Follow up
Clinical examinations
n = 59 (53.2%)
2 lost to follow up
Outcome measures
n = 58 (52.3%)
3 lost to follow up
MRI scans
n = 57 (51.4%)
4 excluded due to artefact
n = 26 (23.4%)
10 excluded as not true laterals
25 lost to follow up
Telephone
interviews
n = 30 (27%)
Total number of reviews at 2 years
n = 91 (81.2%)
Clinical & radiological reviews
n = 61 (54.9%)
Lost to follow up
n = 20 (18.1%)
Analysis
Fig. 1 CONSORT ow diagram.
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behind the PL aspect of the tibial remnant to
target PLB tibial tunnel. All stable remnants of
the tibial stump were preserved. Under maximal
manual tension the knee was cycled 10 times.
Both grafts were xed in full hyperextension
with maximal manual tension on the autografts.
Minimal tension was placed on the LARS graft to
avoid over-constraint of the knee. Tibial xation
was with Intrax screw (DePuySynthes Pty. Ltd.)
for AMB and Milagro Advance screw (DePuy-
Synthes Pty. Ltd.) for the PLB. The nal graft
construct in situ is demonstrated in Fig. 5.
All patients underwent an accelerated reha-
bilitation program supervised by a single reha-
bilitation center. In the rst three weeks,
immediate weight bearing and full knee move-
ments were encouraged. An extension brace was
used to minimize pain and swelling. Rehabilita-
tion protocol is summarized in Table 1. Staged
progression through this was based on knee pain,
swelling and motion.
Fig. 2 (Color online) Prepared hybrid graft with ham-
strings graft and LARS 133 prosthesis before implantation.
Fig. 3 Position of the femoral tunnel awl mark prior to
drilling femoral tunnels (left knee).
Fig. 4 Position of the tibial aiming jig for the AMB with
tibial remnant in situ.
Fig. 5 Final graft position.
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Clinical Assessment
At 1 and 2 years post-operatively, a single expe-
rienced orthopedic physiotherapist assessed 59
patients. Data were recorded for presence of ef-
fusion, range of motion (as measured with a go-
niometer), Lachmans, Anterior Drawer, Pivot
Shift tests and KT-1000 arthrometry as well as
IKDC subjective & objective scores, Tegner Ac-
tivity Scale, Lysholm Knee Score, Cincinnati Knee
Rating and ACL Quality of Life Scores.
Patients were also asked about the time taken
in weeks post-surgery that it took them to
achieve specic goals related to both activities of
daily living and returning to sports. These data
were collected prospectively at 2, 6, 16 weeks and
1 and 2 years. These milestones are outlined in
results (Table 2C).
Patients undergoing telephone interviews
were asked questions related to their current
functional stability, level of sport, surgery or
scans since the reconstruction and their ability to
return to pre-morbid work and sport related ac-
tivity. The standard phone interview questions
are shown in results (Table 2D).
Radiological Evaluation
At 1 and 2 years post-operatively consenting
patients underwent a Gadolinium (dGEMRIC)
MRI with a single Sigma GE 1.5T MRI scanner
(Perth Radiological Clinic), interpreted by a se-
nior radiologist with over 15 years of musculo-
skeletal experience. Imaging was conned to
3 mm thick slices with a 0.5mm gap between
each slice. Coronal, axial and sagittal sequences
were performed pre and post contrast. These
images were used to determine tibial tunnel
positions, evidence of progressive tunnel widen-
ing, graft impingement, cyclops lesions and
synovitis.
Tibial tunnel positions were measured as a
percentage of the antero-posterior distance of the
tibial plateau along Amis & Jacobs line as de-
scribed by Colombet et al.
5
(Fig. 6).
A total of 26 patients underwent a lateral plain
lm X-ray with the knee in full extension for the
purposes of evaluating the femoral tunnel posi-
tions. This plain X-ray image was then super-
imposed onto the sagittal slice on the MRI which
best displayed the femoral tunnel insertion point
on the medial wall of the lateral femoral condyle
of both the anteromedial and posterolateral bun-
dles. The Radiographic Quadrant Method was
then used to dene these positions as described by
Bernard et al.
2
(Fig. 7). Tunnel widening was
Key -
Yellow - AMB position
Blue - PLB Position
Fig. 6 Tibial tunnel positions. Measured from the sagittal
slice of the MRI best depicting the AMB and PLB entry
points into the joint. The normal values for the AMB and
PLB are 36% and 52% along the length of Amis & Jacobs
Line as described by Colombet.
Table 1 Rehabilitation Protocol Post Hybrid
ACLR.
Task Time Allowed Post-operatively
Weight bearing Immediately
Full range of motion Immediately
Walk brace free 3 weeks
Closed chain exercises 3 weeks
Jogging 8 weeks
Open chain exercises 8 weeks
Cutting/change of direction exercises 16 weeks
Full sport 6 months
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dened as interval change in tunnel diameters
across the 1 and 2 year MRI scans as measured on
the sagittal MRI scan 1 cm below the chondral
surface. Tunnel conuence was dened as overlap
of the tunnels at the joint surface interface result-
ing in no bony bridge between them. Cyclops
lesions were recorded.
Gadolinium MRI examination was chosen in
this study to assess ACL graft signal intensity as
part of a second comparative study assessing
graft stress shielding.
RESULTS
Patient Demographics and Follow Up
A total of 111 patients (73 males, 38 females) with
a mean age of 33.8 years (range 1654) and a
mean time to follow up of 2.42 years (range 2447
months) consented for this study. Around 91
(82%) of the patients were reviewed. Of the 111
patients, 59 had a clinical and MRI review. A
further 30 patients had a standardized telephone
interview conducted. A subgroup of the 111
patients had an MRI/X-ray composite study to
examine femoral tunnel positions.
CLINICAL AND RADIOLOGICAL
EVALUATIONS
Overall we found satisfactory subjective and ob-
jective clinical outcomes in this cohort. Of the 59
patients reviewed clinically there were no patients
with a loss of range of full extension greater than
5. 7 patients (11.9%) had a loss of full extension
between 0and 5. The reconstructed knees were
mostly stable with no graft failures and only 2
patients had a KT-1000 side-to-side difference
greater than 3 mm. The mean KT-1000 side-to-side
difference for the 59 patients assessed at 2 years
was 0.5 mm (þ/1.7). A total of 57 out of the 59
patients assessed had a negative Pivot Shift Test.
The 2 year outcomes of anterior laxity and range of
motion are displayed in Table 2A.
About 98% of patients scored an A or B on the
IKDC Objective Score. Subjective and objective
outcome measures are displayed in Table 2B. The
mean time to return to jogging was 18.4 weeks (þ/
23.9). Time taken to achieve activities of daily living
and sports related activity are shown in Table 2C.
The results of the standardized phone questionnaire
for patients that did not have a clinical review at 2
yearsareshowninTable2D. Of the 30 patients
having telephone reviews, 29 reported a stable knee
at 2 years post-operatively and 28 of the 30 patients
would have repeated their index operation.
Satisfactory tunnel positions are demonstrated
in Figs. 8and 9displaying the mean and ana-
tomical averages of tibial and femoral tunnels,
respectively. There was no evidence of synovitis
or progressive tunnel widening on any of the
MRI scans. A total of 15 patients had MRI evi-
dence of a cyclops lesion. Only one of them had a
notchplasty due to loss of full extension.
Complications
Of the 91 patients reviewed 2 years post-opera-
tively there was 1 patient who required revision
surgery for graft failure.
HEIGHT
DEPTH
Fig. 7 (Color online) Fused MRI (black & white) and ra-
diograph (color). The Radiographic Quadrant Method
demonstrating the femoral tunnel position as seen on the
sagittal MRI slice best showing the AMB/PLB entry to the
medial wall of the lateral femoral condyle.
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Table 2 Clinical Measures.
2A Measures of knee laxity and range of motion
Clinical Measure Data (n ¼59)
Anterior laxity KT1000 (mean þ/SD) (mm) 0.5 þ/1.7
KT 1000 laxity <3 mm (%) 93.3
Pivot Shift (%)
ve 96.6
þve 3.4
Extension loss (>5) (%) 0
Extension loss (05) (%) 11.9
2B Subjective and objective outcome measures
Questionnaire Data (n¼58)
IKDC Objective Score (%) A 62; B 36; C 2;
IKDC Subjective Score (mean þ/SD) 86.5 þ/11.6
Tegner 6.5 þ/2.0
Lysholm 87.1 þ/8.9
Cincinnati 378.8 þ/41.5
ACL Quality of Life 81.5 þ/19.3
2C Time to return to activity patents asked to estimate the time
(weeks) taken to achieve each task
Task achieved (mean þ/SD) (weeks) Data (n¼60)
Walk without crutches 2.4 þ/1.6
Walk without a limp 8.2 þ/9.5
Walk on uneven ground 6.3 þ/4.6
Climb a ight of stairs 5.8 þ/3.5
Stand one leg (reconstructed knee) 5.6 þ/3.7
Drive a car (automatic) 3.6 þ/3.4
Drive a car (manual) 4.9 þ/3.5
Return to light manual work (e.g. desk job) 3.6 þ/2.6
Return to moderate manual work (e.g. domestic work) 6.3 þ/4.7
Return to heavy manual work (e.g. building) 11.2 þ/8.9
Achieve full range of movement 22.7þ/30.4
Jogging 18.4 þ/23.9
Stationary cycling 14.8 þ/28.0
Road cycling 10.4 þ/8.5
Running (full pace, straight line) 27.1 þ/31.8
Running with change of direction 33.6 þ/35.0
Level 1 Sports (Jogging, golf, tennis, badminton, cricket) 34.3 þ/37.1
Level 2 Sports (Squash, basketball, netball, athletics) 53.2 þ/41.7
Level 3 Sports (Football, rugby, soccer, hockey) 62.2 þ/40.5
2D Standardized telephone interview for 2 year follow-up
Question (Y%, N%) Data (n¼30)
Do you feel that your ACL graft is still intact/functional? 86.7, 13.3
Have you had any further surgery since your ACL recon? 33.3, 66.7
Have you had a scan to conrm that it is intact? 30, 70
Have you returned to the sports/level of activity before your operation? 56.7, 43.3
Do you think you would be able to return to that level at this time? 66.7, 33.3
Have you been forced to change profession/occupation due to your knee injury? 0, 100
Would you have the surgery again if you re-ruptured your knee? 93.3, 6.7
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A total of 14 (15.4%) of patients underwent a
further procedure on their knee in the 2-year
follow up. Six patients had further surgery for
menisco-chondral symptoms and six had further
surgery for arthrobrosis causing anterior knee
pain and loss of extension. The reasons for these
surgeries are detailed in Table 3. Arthrobrosis
surgery (notch debridement and lateral
retinacular release) was performed in the rst 12
months post-operatively for anterior knee pain.
The only patient to have an infection was known
to be immune-compromised with a concurrent
hepatitis infection. The clinical and radiological
outcomes of all repeated procedures are further
detailed in Table 4.
DISCUSSION
This study demonstrates that augmentation of
autologous hamstrings with the LARS 133 pros-
thesis coupled with accelerated rehabilitation
does not result in graft laxity at 2 years follow-up.
In the context of accelerated rehabilitation, we
have demonstrated that graft failure and laxity
does not occur as has been shown with autolo-
gous hamstrings grafts without augmentation.
7,12
This is the rst study of a four tunnel ACLR
where prosthetic augmentation of the AMB has
been performed. While many studies report time
patients are allowed to perform an activity in
rehabilitation post-ACLR, to our knowledge this
is the rst study to measure the time the patient
actually performed desired rehabilitation activi-
ties. In the setting of prostheses for ACL graft
choice we have demonstrated that the use of the
LARS 133 as an augmentation device is not as-
sociated with increased rate of synovitis or
osteolysis. While this study reports excellent sta-
bility and subjective and objective results, there is
an unacceptably high re-operation rate. We con-
sider a place for autologous hamstrings graft
Fig. 9 (Color online) Results for femoral tunnel positioning
using the Radiographic Quadrant Method with the normal
values for the AMB (height 75%, depth 75%) and PLB
(height 66%, depth 50%) represented in white and the cohort
(mean þ/SD) (AMB: height 75.4 þ/2.9, depth 71.9 þ/
4.9; PLB: height 59.2 þ/6.6, depth 53.2 þ/8.0) repre-
sented in red.
Mean Positions
Normal Positions
Key -
Blue - AMB positions
Yellow - PLB Positions
% +/- SD
Normal AMB 36
Cohort AMB 38.3 +/- 6.2
Normal PLB 52
Cohort PLB 52.9 +/- 5.5
Fig. 8 Results of tibial tunnel positions (mean) with respect
to the normal values determined by Colombets cadaveric
study.
Table 3 Repeat Operations in the Two
Years Post-Surgery.
Procedure Data (n=91)
Revision ACLR 1, (1.1%)
Arthrobrosis surgery 6, (6.6%)
Arthroscopy for meniscal pathology 6, (6.6%)
Washout for infection 1, (1.1%)
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Table 4 Clinical & Radiological Outcomes of Patients having Repeat Operations.
Arthrobrosis surgery for loss of extension
Clinical review ROM KT1000 Tegner IKDC IKDC(O)
MRI
Cyclops
Time to
Jogging (wks)
Time to L1
Sport (wks)
Pt 1 0128 3.3 7 70 B Yes 4 12
Pt 2 0135 3.3 2 68 B No 10 Not achieved
Pt 3 0130 1.7 5 59 A No 20 20
Phone Interviews
Graft
Intact?
Return to
Pre-Injury Sport?
Change
Occupation?
Have an
ACLR Again?
Pt 4 Y N N N
Pt 5 Y Y N Y
Pt 6 Y N N Y
Arthroscopy for meniscal or chondral pathology
Clinical Reviews ROM KT1000 Tegner IKDC () IKDCO
MRI
Cyclops
Time to
Jogging(wks)
Time to L1
Sport (wks)
Pt 7 0130 1.7 6 72 B No 36 Not achieved
Pt 8 3130 1.0 5 67 B No 12 30
Pt 9 0130 3.0 5 62 C No 12 16
Pt 10 0125 2.0 5 85 A Yes Not achieved Not achieved
Phone Interviews
Graft
Intact?
Return to
Pre-Iniury Sport?
Change
Occupation?
Have an
ACLR Again?
Pt 11 Y N N Y
Pt 12 Lost to
follow-up
Repeat procedure for infection
Clinical Review ROM KT1000 Tegner IKDC(S) IKDC(O)
MRI
Cyclops
Time to
Jogging (wks)
Time to L1
Sport (wks)
Pt 13 2135 3.7 5 71 B N/A 60 Not achieved
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augmentation in the setting of acceleration return
to life and sporting activities, however this graft
construct may come with a high re-operation
rate.
It is accepted within the literature that graft
choice limits the rate at which patients are per-
mitted to return to high-level activity.
35
It has
been demonstrated in autologous hamstrings that
accelerated rehabilitation leads to adverse out-
comes in terms of graft laxity and failure rate
(Table 5).
8,13,25,26,32
Studies allowing running at
two months post-operatively showed increased
SSD at KT-1000 arthrometer testing at 2 years
with SSD >3 mm SSD of 1118% and graft failure
rates of 810%.
13,27
Pinczewski et al.
27
reported in
his hamstring graft patients with SSD >2mm at
2 years had an increased failure rate at 5-year
review. Interestingly, Hamido et al. who used the
same prosthesis as used in this study to augment
small or failed hamstring graft harvests had low
KT-1000 measures at 2 years.
11
By augmenting
hamstrings with the rigid synthetic ligament we
believe the ACL graft is protected from length-
ening during the healing phase as demonstrated
by this studysnding of a low KT-1000 mean
(0.5 mm) and 93.3% of patients having a mean
side-to-side difference of less than 3 mm.
The augmentation of the AMB with a prosthetic
ligament is an original concept. It was felt the
AMB autograft was at most risk of elongation
during the early phase of accelerated rehabilita-
tion. The PLB has been considered a cause of early
graft failure in 4-tunnel ACLR and augmentation
of this bundle may lessen that risk. Augmentation
in this study was aimed to lessen the risk of AMB
graft elongation, not PLB rupture.
The use of prosthetic ligaments as a stand-
alone graft has been recently revisited. Cited
advantages include earlier recovery times al-
though there is a paucity of detailed reporting of
this outcome in the literature.
3,14,22,24
Our study is
the rst to systematically examine the rate at
which patients return to both lifestyle and sports
activities. An interesting nding in this study was
the difference between guidelines to achieve ac-
tivities and the longer patient reported times.
While patients were permitted to jog at 2 months
and return to full sporting activities at 6 months,
the mean time taken to actually achieve these
activities was 18.4 weeks and 34.3 weeks, re-
spectively. The reason for this is unclear. Patients
may be reluctant to re-injure their knee again or
have a low desire to return to these activities.
Also the physiotherapy regime was a step-wise
progression based on knee swelling, pain and
function rather than the absolute threshold times
displayed in Table 1. Patients having repeated
procedures also had delayed return to activities
(Table 4) and may have affected these results.
While this graft conguration aims for faster re-
covery times it remains unknown how important
time patients take to return to life and sport ac-
tivities inuences patient satisfaction post-ACLR.
The failure rate in this series (1.1%) was com-
parable with previously reported double bundle
ACL reconstructions and standard rehabilitation.
Two year failure rates range from 1% to 3%
9,15,33
in level 1 studies. While common causes for early
graft failure include knee laxity, poor tunnel po-
sitioning and younger patients returning to sport
with high cutting eventsports. In this study,
satisfactory knee stability and tunnel positioning
were noted. While early return to sport is recog-
nized as a risk factor for early failure, the time to
failure in this study was 1.676.1 years.
Two important potential causes of graft failure
have however been identied. Firstly patients in
this series were offered two great graft choices, a
standard autograft with standard rehabilitation
or a hybrid graft with faster return to sport. The
group choosing the hybrid and faster recovery
time may have a differing psychological prole to
the group choosing a more traditional graft.
Ardern et al.
1
have shown that a patients
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psychological prole is an important inuence on
ACLR outcomes and may contribute to an ability
to return to sport. Patients choosing a faster re-
habilitation may also return earlier and return to
higher level cutting sports.
The second consideration is that graft shielding
from the LARS prosthesis may delay autograft
ligamentization and create a weaker graft cong-
uration. This may cause higher graft failure rates.
At 2 years, we have not seen this yet. Long-term
follow-up is required to address this question.
The overall re-operation rate was 15.4% al-
though for meniscal and chondral pathology re-
operation rate of 6.6% was comparable to previ-
ous studies.
8,13,25,26,32
Additionally there were six
patients who required arthroscopic surgery for
symptoms of anterior knee pain or loss of ex-
tension (Table 4). These patients requiring re-
operation had slower recovery time and lower
IKDC subjective scores compared with the study
average, although similar scores to the patients
re-operated on for meniscal or chondral pathol-
ogy. The cause for these high re-operation rates is
not readily apparent. In this study, loss of ex-
tension was measured from the zero position.
While there were no patients with a loss of ex-
tension greater than 5, 11% of the cohort had
some loss of extension recorded. If this loss was
in a patient with ligamentous laxity and hyper-
extension on the contralateral (and pre-injured)
knee a small measured loss of extension could
by quite signicant and symptomatic. Tunnel
positions were satisfactory and the augmentation
device was chosen specically for its small cross-
sectional area (9 mm
2
) adding only 1 mm of tun-
nel diameter dimension.
Both a remnant sparing and a 4 tunnel ACLR
technique used in the study may create a con-
straining graft.
10,34
Remnant sparing may also
increase the graft remnant volume causing im-
pingement. Additionally, the augmentation de-
vice itself is a stiff construct with a xed working
length. It is possible that this graft type and sur-
gical technique has the potential to over-constrain
the knee leading to symptoms of knee stiffness.
This was also reected by the fact that our mean
side-to-side difference (0.5 mm) was compara-
tively low within the current literature (Table 5).
When we examined our data further we also
found that 17 patients (28.9%) had a negative
side-to-side KT-1000 result suggesting that their
reconstructed knee was tighter than their con-
tralateral knee. The augment was added to a
double bundle hamstring conguration in this
study, as this was the senior authors preferred
graft at the time. While the two-year subjective
and clinical results are satisfactory, a graft that
over-constrains the knee could increase chondral
wear. Based on these concerns of knee over-con-
straint and the high re-operation rates in this
study we are currently assessing a single bundle
(2 tunnels) hybrid ACLR.
Our study has a number of limitations. There
was signicant selection bias in that patients
Table 5 Laxity Measures & Complications in Studies Allowing Jogging at 2 Months (NR - not Reported).
Author KT1000 (mm) SSD (<3 mm) Re-rupture Rate Re-operation Rate
SB autogaft hamstring
Howell et al. NR 89% 9.8% 17%
Pinczewski et al. 1.7 72% 8% 8.8%
Pan et al. 2.3 75% NR NR
Gao et al. 1.5 NR 1.9% 5%
Hybridautoloqous hamstrinas & LARS 133 (current study group)
Falconer et al. 0.5 93.3% 1% 19.8%
T. M. Falconer et al.
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needed to choose the hybrid type graft and con-
sent to the accelerated protocol. The patients
were recruited from a private practice where it
would be difcult to prospectively randomize the
study. Only 81% of patients had review (54%
clinical and 27% phone). The low rates of two-
year clinical review were supplemented with a
telephone interview, however the results of this
should be considered with caution. We also rec-
ognize that the surgical technique is a technical
one with a steep and long learning curve and
potential intra-operative difculties. While the
two-year clinical and radiological outcomes of
this technique and the use of the LARS ligament
as an augmentation device are promising with
the construct resisting graft elongation, long-term
follow up assessing potential over-constraint is
important.
The premise of this study is that a faster ACLR
recovery will improve patient satisfaction how-
ever this prospective case series was not designed
to demonstrate this. The use of appropriately
matched patient controls or a randomized trial
may also be benecial in displaying the potential
differences with an augmentation device and
accelerated rehabilitation and particularly differ-
ences in patient satisfaction with recovery times.
Assessing actual task recovery times rather than
reporting task allowable times may offer a better
understanding of ACLR recovery.
We conclude that LARS 133 augmentation of
autologous hamstrings ACLR provides a graft
construct allowing accelerated rehabilitation
without graft elongation. It is not associated with
signicant synovitis within the rst two years.
Failure rates are comparable with hamstring
autografts rehabilitated conservatively. Re-oper-
ation rates are however higher. Further investi-
gation may enhance the understanding of our
results. The rates at which patients recover and
return to life and sports activity following
different ACLR graft types appears as a topic of
future research interest.
ACKNOWLEDGMENTS
Funding was received by Dr. Peter Annear from
Corin Pty Ltd, Australia to fund all radiological
investigations for this study. Funding was also
received to pay for a part time research assistants
position who was appointed independently.
We represent that this submission is original
work, and is not under consideration for publi-
cation with any other journal.
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... Augmentation of ACLR autografts with synthetic material is a recognized technique proposed to facilitate and accelerate rehabilitation. 18,19,20,32 Fears regarding noninfective synovitis with effusion were noted with earlier generations of intra-articular synthetic devices, but new generations, such as the Ligament Augmentation and Reconstruction System (LARS; Surgical Implants and Devices), have shown low rates of 0.2%. 35 This is in contrast to earlier devices that had high failure and synovitis rates and an increased risk of early-onset osteoarthritis. ...
... The reported failure (retear) rate of 2.0% in the current study is comparable with the rates in other similar studies. 2,12,20 First-generation synthetic augmentations used intra-articularly did cause concerns regarding noninfective synovitis, persistent effusion, early failure, and potentially early degeneration of chondral surfaces. 10,33 We found none of these issues within the study population. ...
... The overall result led to only 7% of patients having a side-to-side difference >3 mm at 2 years. 20 Bodendorfer et al 12 conducted a similar comparative cohort study to the current study, assessing the differences between single-bundle 4-strand hamstring ACLR with or without suture augmentation using the InternalBrace (Arthrex). They reported outcomes in 30 augmented ACLRs and a matched cohort of 30 hamstring-only ACLRs at 2 years and demonstrated that having a suture-augmented construct predicted a greater improvement in IKDC scores and KOOS Sport and Recreation and Quality of Life subscores, among other outcomes. ...
Article
Full-text available
Background Few studies have reported the return-to-sports (RTS) rate in patients after augmentation of autologous anterior cruciate ligament reconstruction (ACLR) with the Ligament Augmentation and Reconstruction System (LARS). Purpose/Hypothesis The purpose of this study was to compare postoperative outcomes in patients who underwent ACLR with single-bundle 4-strand hamstring autograft either without augmentation (HA-ACLR group) or with LARS augmentation (AUG-ACLR group). It was hypothesized that clinical outcomes and RTS rates would be better in the AUG-ACLR group at the 1-year follow-up, with similar outcomes in both cohorts by 2 years. Study Design Cohort study; Level of evidence, 3. Methods Patients who underwent ACLR between April 2014 and December 2017 were included in the current comparative study if they were skeletally mature and had 1- and 2-year follow-up outcomes; patients with concomitant meniscal surgery were also included. Included were 66 patients with AUG-ACLR (mean age, 26.8 years; 67% male) and 130 patients with HA-ACLR (mean age, 27.5 years; 61% male). Subjective outcome measures included the International Knee Documentation Committee Subjective Knee Evaluation Form, Knee injury and Osteoarthritis Outcome Score, Lysholm scale, Tegner activity scale, and the Noyes sports activity rating scale. Objective measures included knee laxity, maximal isokinetic knee flexion and extension strength, and the results of 4 functional hop tests. Results There were no significant differences between the study groups in age, sex distribution, body mass index, time to surgery, or number of concurrent meniscal surgeries. At the 1-year follow-up, the AUG-ACLR group had a significantly higher Tegner score ( P = .001) and rates of RTS ( P = .029) and return to preinjury level of sport ( P = .003) compared with the HA-ACLR group. At the 2-year follow-up, there were no differences in these measures between groups. There were no between-group differences in other subjective outcomes, knee laxity, or strength and hop test results at either postoperative time point. There were also no differences in rerupture rates or other complications between the groups. Conclusion Patients with AUG-ACLR had higher 1-year postoperative Tegner scores and rates of RTS and preoperative sport level compared with the HA-ACLR group. The 2-year rerupture rate for the AUG-ACLR group was low, and no intra-articular inflammatory complications were noted.
... While a recent 10-year longitudinal study 9 demonstrated satisfactory clinical outcomes and failure rates in patients undergoing primary ACLR employing a synthetic ligament and remnant preservation, excessive synovitis and high failure rates have limited their ongoing use in earlier studies. 26,27,29,36,43,45,63,64 In an attempt to improve clinical outcomes and reduce reinjury rates, particularly in patients with higher activity levels and those seeking an earlier RTS, concomitant extra-articular procedures such as anterolateral ligament reconstruction, 10 as well as methods of ACLR employing an autograft or allograft augmented (or reinforced) with a synthetic device, 14,19,20,49,51 have been proposed. As previously reported by Falconer et al, 14 the proposed advantage of the combined intra-articular autograft/Ligament Augmentation and Reconstruction System (LARS; Corin Group) construct is to permit early ACL reinforcement and accelerated rehabilitation without the increased risk of graft stretching and/or failure. ...
... 26,27,29,36,43,45,63,64 In an attempt to improve clinical outcomes and reduce reinjury rates, particularly in patients with higher activity levels and those seeking an earlier RTS, concomitant extra-articular procedures such as anterolateral ligament reconstruction, 10 as well as methods of ACLR employing an autograft or allograft augmented (or reinforced) with a synthetic device, 14,19,20,49,51 have been proposed. As previously reported by Falconer et al, 14 the proposed advantage of the combined intra-articular autograft/Ligament Augmentation and Reconstruction System (LARS; Corin Group) construct is to permit early ACL reinforcement and accelerated rehabilitation without the increased risk of graft stretching and/or failure. This study presents a remnant-sparing surgical technique for ACLR employing autologous hamstrings augmented with the LARS, together with clinical outcomes for 50 patients who underwent the technique. ...
Article
Full-text available
Background There are a number of surgical methods for undertaking anterior cruciate ligament (ACL) reconstruction (ACLR), although relatively high rates of ipsilateral retears and contralateral tears exist, with only 65% of patients returning to their preinjury level of sport. ACLR techniques adopting synthetic augmentation have been proposed in an attempt to improve clinical outcomes and reduce reinjury rates. Purpose To determine the efficacy of ACLR using autologous hamstrings augmented with the Ligament Augmentation and Reconstruction System (LARS). Study Design Case series; Level of evidence, 4. Methods A total of 65 patients were prospectively treated with arthroscopically assisted single-bundle ACLR using hamstrings augmented with the LARS, of whom 50 were available for 1- and 2-year reviews. Patient-reported outcome measures (PROMs), KT-1000 arthrometer testing, knee range of motion, peak isokinetic knee strength testing, and a battery of 4 hop tests were employed. Limb symmetry indices (LSIs) were calculated. Analysis of variance was used to evaluate differences over time and between limbs. Data on return to the preinjury level of sport, retears, and reoperations were collected. Results High PROM scores were demonstrated at 1 and 2 years. Before the injury, 47 patients (94%) were actively participating in level 1 or 2 sports, with 38 (76%) and 43 (86%) patients having returned at 1 and 2 years, respectively. Normal (<3 mm; 90%) or nearly normal (3-5 mm; 10%) KT-1000 arthrometer side-to-side differences were observed at 2 years. Apart from knee flexion ( P < .0001), extension ( P = .001), and the 6-m timed hop ( P = .039), there were no between-limb differences at 1 year, and there were no differences on any objective measures at 2 years (all P > .05). Mean LSIs across all measures were ≥90%. At 2 years, 84% to 90% of patients were ≥90% on the hop tests, with 72% and 76% of patients having ≥90% for extension and flexion strength, respectively. Two reoperations were undertaken for meniscal tears (7 and 8.5 months), 1 patient (2%) suffered a retear at 7 months, and 2 patients (3%) suffered a contralateral tear (8 and 12 months). Conclusion This augmented ACLR technique demonstrated good clinical scores, a high rate of return to sport, and low rates of secondary ruptures and contralateral ACL tears at 2 years. Some caution should be noted in interpreting these results, as 15 of 65 patients (23%) were not included in the 2-year follow-up.
... There is a diminished level of graft strength and stiffness observed during the early tissue revascularization process [11], with an associated requirement to control patient activity and associated graft stress with early accelerated rehabilitation potentially risking excessive graft laxity which can be associated with subsequent instability and/or re-injury [27]. Therefore, ACLR surgical techniques augmenting (or reinforcing) an auto or allograft with a synthetic device have been reported [2,4,8,10,13,32], though high rates of synovitis, early osteoarthritic change and failure rates limited the early use and subsequent adoption of synthetics for ACLR [16,18,19,21,22,29,30]. ...
Article
PurposeTo compare the clinical and radiological outcomes in patients undergoing anterior cruciate ligament reconstruction (ACLR) with, or without, LARS augmentation.Methods One-hundred and thirty-six patients that underwent double-bundle ACLR with (DB Hams/LARS, n = 67), or without (DB Hams, n = 69), LARS augmentation, were assessed clinically and with Magnetic Resonance Imaging (MRI) at a minimum of 7-years post-surgery. Patients were assessed via patient-reported outcome measures (PROMs), KT-1000 (laxity), isokinetic knee extensor and flexor strength and a 4-hop test battery. Limb symmetry indices (LSIs) were calculated. The Whole-Organ Magnetic Resonance Imaging Score (WORMS) evaluated knee status via MRI. Sport participation, secondary operations, ACL re-tears and contralateral ACL tears were reported.ResultsNo differences (n.s.) were observed in demographics, PROMs, KT-1000 scores or strength and hop LSIs. Normal (< 3 mm side-to-side differences) KT-1000 scores were observed in 64 (92.8%) and 59 (88.1%) of DB Hams and DB Hams/LARS patients, respectively. Comparative rates of satisfaction were reported. Knee flexor strength and hop test LSIs were all ˃95% in both groups, which was 94.2% and 96.7% for knee extensor strength in the DB Hams and DB Hams/LARS cohorts, respectively. While 53 (76.8%) and 52 (77.6%) of the DB Hams and DB Hams/LARS patients had returned to pivoting sports, 42 (60.9%) and 41 (61.2%) were participating in pivoting sports at the minimum 7-year review. No difference (n.s.) was observed in the WORMS (12.3 DB Hams, 16.7 DB Hams/LARS). Of the cohort assessed, 8 (11%) DB Hams and 11 (16%) DB Hams/LARS patients had undergone secondary surgery. In addition to one patient in each group that demonstrated ACL rupture on MRI, an additional cohort of patients were excluded from the current analysis due to prior re-tear (DB Hams n = 6, DB Hams/LARS n = 8) or contralateral ACL tear (DB Hams n = 4, DB Hams/LARS n = 4).Conclusions Comparable outcomes were observed after double-bundle ACLR using autologous hamstrings with, or without, LARS augmentation. Therefore, while these outcomes do not justify the additional use of synthetic augmentation given the lack of further benefit and additional cost, higher rates of graft failure, synovitis and early osteoarthritic change previously reported were not observed.Level of EvidenceIII.
... This observational study was designed to investigate patients returning for testing as part of a larger cohort study to evaluate the clinical outcomes of the Hybrid graft configuration [13]. It was a retrospective analysis of prospectively collected data. ...
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Introduction: Understanding factors that cause loss of extension post Anterior Cruciate Ligament (ACL) reconstruction may assist surgeons in preventing this problem. The aim of this clinical trial is to determine the effect of reconstructed ACL graft size on postoperative range of motion in ACL reconstruction in human subjects. Methods: This therapeutic comparative cohort study consisted of a retrospective analysis of prospectively collected data. Participants either received an autologous double bundle ACL graft (Control) or a combined autologous/synthetic graft (Hybrid), which increased graft cross-sectional area. Femoral notch width was measured preoperatively by Magnetic Resonance Imaging. Range of motion was determined using goniometry at two years post reconstruction. Stepwise logistic regression and bivariate correlation was used to analyse data. Results: 54 participants were included in analysis, 22 Control and 32 Hybrid. Hybrid group had a significantly larger reconstructed graft cross-sectional area (× (Hybrid)=71 ± 9.30 mm2; × (Control)=59 ± 12.26 mm2, t=4.76, p<0.05). Mean notch size was smaller in Control group (1.83 ± 0.18 cm) compared to Hybrid group (1.91 ± 0.27 cm). Hybrid group had significantly fewer cases of postoperative knee extension loss (χ2=3.90, p<0.05), defined as loss of passive range ≥ 3° at 2 years post-surgery. Increased graft cross-sectional area was not a significant predictor of loss of extension. There was also no relationship between notch width and extension range of movement. (r=0.01, p=0.80). Conclusion: A 20% increase in ACL graft cross-sectional area was not a significant predictor of postoperative extension loss. graft options [9]. Upsizing
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Anterior cruciate ligament (ACL) injuries often result in functional disability, particularly in jumping, cutting, and deceleration activities. Some patients can accommodate to this functional loss, while others require surgical reconstruction of the ligament to provide stability and to protect the meniscus from further injury. Nonoperative management involves an intensive rehabilitation program, patient counseling about high-risk activities, and measures to prevent recurrent injuries. Surgical reconstruction of the ACL involves the technical factors of graft selection, positioning, fixation, and tensioning and the avoidance of stress risers. A supervised and intensive rehabilitation program is necessary to achieve optimal results.
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Three different techniques of anterior cruciate ligament (ACL) reconstruction--conventional (transtibial) single bundle (CSB), anatomic single bundle (ASB), and anatomic double bundle (ADB)--have been described. To determine if double-bundle reconstruction is needed to restore rotational stability or if anatomic placement of a single bundle can yield similar results. Randomized controlled trial; Level of evidence, 1. From December 2005 to December 2007, 320 patients were prospectively randomized into 3 groups: ADB, ASB, and CSB reconstruction. The average follow-up was 51.15 months (range, 39-63 months). At the final follow-up, 281 patients were available. In all groups, hamstring tendons were used with suspensory fixation on the femoral side and bioabsorbable interference screw fixation on the tibial side. The outcomes were evaluated by an independent blinded observer using the Lysholm score and subjective International Knee Documentation Committee (IKDC) form. The KT-1000 arthrometer was used to evaluate anteroposterior stability, and the pivot-shift test was used to determine rotational stability. Anatomic single-bundle reconstruction resulted in better anteroposterior and rotational stability than CSB reconstruction (average side-to-side difference for anterior tibial translation was 1.6 mm in the ASB group vs 2.0 mm in the CSB group; P = .002). Negative pivot shift was 66.7% vs 41.7% (P = .003). In other parameters, the differences between groups were not statistically significant. The results of the ADB group were also superior to the ASB group for anteroposterior and rotational stability (average side-to-side difference for anterior tibial translation was 1.2 mm in the ADB group vs 1.6 mm in the ASB group; P = .002). Negative pivot shift was 93.1% vs 66.7%, respectively (P < .001), and range of motion was also significantly different (P = .005). The Lysholm score was 90.9, 91.8, and 93.0 in the CSB, ASB, and ADB groups, respectively. The difference was significant only when we compared ADB and CSB (P = .025). Subjective IKDC scores were 90.2, 90.6, and 92.1 in the CSB, ASB, and ADB groups, respectively. The difference was not significant. Anatomic double-bundle ACL reconstruction is significantly superior to conventional single-bundle ACL reconstruction and better than anatomic single-bundle reconstruction. Anatomic single-bundle reconstruction was superior to conventional single-bundle reconstruction. However, these differences are small and may not be clinically relevant.
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Forty-eight patients were enrolled in a study to determine the time interval for maturity and remodeling following arthroscopically assisted autogenous anterior cruciate ligament reconstruction (ACLR). Two biopsy specimens, one superficial and one deep, at the same level in the midsubstance of the ACL were obtained. Graft age, time from ACL reconstruction to biopsy, ranged from 3 months to 120 months. The patients were placed into four groups, (1) 3 to 6 months, (2) 7 to 12 months, (3) more than 12 months, and (4) control, in accordance with the time following ACL reconstruction. Each specimen was independently evaluated using light microscopy by two different observers in a blinded design. The biopsy specimens were evaluated for vascularity, cellularity, fiber pattern, and metaplasia when compared with the normal ACL. None of the patients was protected from activity as a result of ligament biopsy and no adverse outcomes were reported as a result of biopsy. Our study showed that fiber pattern, cellularity, vascularity, and degree of metaplasia obtained gross histological similarity with a normal ACL by 12 months after autogenous reconstruction. Unexpectedly, no significant statistical differences were noted for all grafts more than 6 months after ACLR, for two of the histological features studied, vascularity and fiber pattern, P=.05. We conclude that by 12 months after autogenous ACLR, graft maturity resembles a normal ACL. Additionally, because no statistical differences were noted in vascularity and fiber pattern after 6 months following autogenous ACLR, significant graft maturity may occur before 12 months. This may allow early postoperative return to full activity and support proponents of accelerated rehabilitation programs following autogenous ACLR.
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The aim of this multicenter study was to evaluate the clinical outcome of anterior cruciate ligament (ACL) reconstruction by use of the Ligament Advanced Reinforcement System (LARS) artificial ligament (Surgical Implants and Devices, Arc-sur-Tille, France) with 3- to 5-year follow-up. From August 2004 to July 2006, 159 patients with ACL rupture underwent arthroscopic ACL reconstruction with LARS artificial ligament at 4 orthopaedic sports medicine centers in China. They were retrospectively followed up for 50 +/- 6 months (range, 36 to 62 months). Outcome assessment included physical examination, KT-1000 arthrometer testing (MEDmetric, San Diego, CA), magnetic resonance imaging, radiography, Lysholm score, Tegner score, International Knee Documentation Committee score, and subjective satisfaction rate. Quadriceps and hamstring isokinetic strength was evaluated in 68 patients. The side-to-side difference in anterior translation (injured side - uninjured side) measured by KT-1000 arthrometer was 1.5 +/- 1.6 mm (range, -1 to 7 mm) postoperatively, and knee stability was significantly improved compared with preoperative data (P < .0001). Quadriceps and hamstring isokinetic peak torque of the injured limb expressed as a percentage of the contralateral limb was 93.6 +/- 10.7 and 95.8 +/- 12.0, respectively. The Lysholm score improved from 65.1 +/- 12.3 points (range, 30 to 95 points) preoperatively to 94.5 +/- 7.0 points (range, 65 to 100 points) postoperatively (P < .0001). The Tegner score improved from 3.1 +/- 1.6 (range, 0 to 6) preoperatively to 6.1 +/- 1.5 (range, 1 to 9) postoperatively (P < .0001). According to the International Knee Documentation Committee score, 94% of patients were graded A or B at last follow-up. Ninety-three percent of patients were very satisfied or satisfied with their outcome. LARS artificial ligament rupture occurred in 3 patients; knee synovitis developed in 1 of these patients. ACL reconstruction with LARS artificial ligament used in patients with the ACL stump preserved in the acute and chronic phases has a very good outcome at mean of 50 months' follow-up. The overall complication rate for ACL reconstruction with LARS artificial ligament is 5.7%, and knee synovitis developed in only 1 case. Level IV, therapeutic case series.