Remnant preservation versus remnant debridement in ACLR, a 10 year follow-up of a prospective randomized control study

Abstract

Introduction and Aims (50 words):
Background: Anterior cruciate remnant preservation may be beneficial in Anterior Cruciate Ligament Reconstruction (ACLR). Gohil, Annear & Breidahl (Sept, 2007) used a grade 1 randomised controlled trial to compare the two methods and at short term follow-up, the minimal debridement technique demonstrated earlier revascularisation within the ACL graft at 2 months, and suggested improved strength at 6 months based on radiological imaging. Unfortunately, this did not translate through to clinical benefits in the early 12 month post operative period. Zhang, L et al. (May, 2013) and Naylor, AJ et al. (2013) reiterated that remnant preservation may improve graft revascularization and knee proprioception. Takazawa Y et al. (Sept, 2013) demonstrated that minimal debridement may facilitate recovery of function and decreased graft rupture at two years post primary reconstruction. However, studies have yet to show consistent significant clinical advantages and follow-up has only been analysed over 1-2 years.
Purpose: This current study reported results over a long-term follow-up of 10 years post operation for the same participants from the Gohil, Annear & Breidahl (2007) study.

Method
Study Design: The review was based on level 1 randomised controlled trial chart review. Methods: All 49 participants (25 standard – group 1, and 24 remnant preserving group – group 2) from the previous study have been included for investigation. The chart review recorded demographic data, graft rupture, re-operation rates, and associated clinical failures of the ACLR. The review presents comparative data between the two groups.

Results
At 10 year follow-up, the remnant retention ACLR group only had better outcomes for ipsilateral graft rupture (2 patients versus 3 patients). Standard ACLR group had improved outcomes for contralateral graft rupture (2 versus 3), ipsilateral other knee post operative surgery (5 versus 10), ipsilateral knee post operative complaints (7 versus 12), and other non-knee post operative issues (3 versus 4). Non of the differences were statistically significant.

Conclusion: Overall our results suggested no statistically significant difference between the remnant retaining and standard technique for ACLR in these 49 subjects using chart review endpoints of graft revision and knee reoperation rates. The review is limited by a small study group and a chart only review. A larger study group with long term clinical outcome measures may offer more definitive conclusions as to the advantages of remnant sparing ACLR. In this 10 year follow-up post ACL reconstruction there has been no distinct advantage identified for either procedure.

Full text

Remnant Preservation
V
Remnant Debridement
in ACL Reconstruction
10 year follow-up from Prospective
RCT
Edward Rohr
Sat Gohil
David Hille
Peter Annear

Faster ligamentization
better graft MRI signal (leveI I Gohil )
better biomechanical and histological healing (animal)
(level I Mafune )
Better stability ( partial ACLR) (level I Pujol)
Better proprioception ( level lV Lee )
Less tunnel enlargement (level 1 Demorag )
(level 1 Zhang )
Literature
Advantages of Remnant Preservation ACLR

Faster ligamentization
better graft MRI signal (leveI I Gohil )
better biomechanical and histological healing (animal)
(level I Mafune )
Better stability ( partial ACLR) (level I Pujol)
Better proprioception ( level lII Adachi )
Less tunnel enlargement (level 1 Demorag )
(level 1 Zhang )
Literature
Advantages of remnant sparing
conclusion
No clinical difference
(Longest follow-up 36 months)

What could long term
follow-up study tell us
?worse
remnant cause late problems?
?better
Better ligamentization
Better proprioception less graft failures
less early”biological”
failures
Cyclops lesions
Pain
LOE
?…..A Clinical difference

Gohil S et al (2007)
(n=49)
Remnant Preservation
n=24
1Year
Clinical and MRI graft signal study
Remnant Debridement
n=25
Retained
-fat pad
-ligamentum mucosum
-all stable remnant
-minimal notch exposure
Place graft
within remnant

Gohil S et al (2007)
(n=49)
Remnant Preservation
n=24
1Year
Clinical and MRI graft signal study
10 Years follow-up
Patient reported outcomes
n=35 (71%)
RP n=18 RD n=17
Chart review
n=48 (98%)
RP n=25 RD n=23
Remnant Debridement
n=25

n=2
P-value = 0.71
9%
12%
Results
Graft failures at 10 years
Standard
(n=25) Remnant
Preservation
(n=23)
n=3
Chart review

8%
(2)
P-value 0.6602
ACL tear other knee
(4)
Standard Remnant
Preservation
17%
Chart review

Std Debridement Min Debridement
Standard Remnant
Preservation
Sample size too small to achieve a p-value
11
49
Mean Time to graft failure
(months post-op)
Chart review

Standard Remnant
Preservation
15
46
Time to graft or contralateral knee
ACL injury (months)
P < 0.07

Standard Remnant
Preservation
P-value < 0.0072
Ongoing knee complaints
(>2 extra post-op visits)
61%
20%
Chart review

Standard Remnant
Preservation
P-value 0.0224
Ipsilateral arthroscopy
44%
12%
Chart review

Reason for
Arthroscopy RP RD
chondral 4 1
Meniscal 4 1
LOE 2 1
other 1 -
Cause for
Repeat arthroscopy
Chart review

Remnant
debridement
Remnant
preservation
P value
Satisfaction
VAS 0-10
8.3 8.1 0.764
% Improvement
Pre to post-op
43 51 0.105
% Current Full Duties
without restriction
72 71 1.0
Patient reported
outcomes

Clear loose remnant
Prepare femoral tunnels
3.2mm drill both tunnels
What caused the pain/
high reoperation rate?
Missed unstable
remnant
Full remnant + 4strand HS
graft too big
“subtle notch impingment”

Remnant volume of anterior cruciate ligament correlates
preoperative patients’ status and postoperative outcome.
Muneta et al 2013 level 3 study
DB hamstring ACL 2 yrs follow-up
Classified retained remnant volume at arthroscopy
well preserved remnant group
had best stability + more LOE
moderate preserved group
had best subjective outcome

Debridement
prevents clinical cyclops lesion
1.Remove ligamentum mucosum + some fat pad
2.View remnant at 300 knee flexion
debride unstable tissue
3. “sculpt” remnant
Changed surgical technique
Discussion

Is the remnant preservation graft
biologically better?
10 year
post-op Graft
graft or other
knee
ACL injury
Mean Time
graft or other knee
ACL injury
RP 2pts 6knees 46
Standard 3pts 5knees 15
Discussion
Patient ACL re-injury

Is the remnant preservation graft
biologically better?
10 year
post-op Graft
Graft or other
knee
ACL Injury
Mean Time
graft or other knee re-
injury
RP 2pts 6knees 46months
Standard 3pts 5knees 15months
P<0.07
Discussion
Patient ACL re-injury

Future study
Time to graft failure:
useful measure of graft biology
Graft failure rates
main outcome measure
Define clinical
value
of Remnant sparing
Large RCT study
ACL Registry with
Remnant classification

Study Limitations
Small sample size
Underpowered for graft failure rates
Follow-up
Chart review
71% subjective data
No objective data
Limited remnant classification

Don’t dismiss completely
Improved Remnant Preservation Technique
remove unstable tissue
“debulk” remnant
At present,,,,,,
“unmeasured” biological
advantage

Conclusion
Remnant Preservation ACLR at 10 years has ….
Higher rates of repeat clinic visits
Higher rates of post-operative arthroscopy
Later times of combined ACL graft and contralateral ACL
re-injury

Thank you
VV

6 month min debrid’t group
Early return to normal signal
?Early return to normal strength
?Early return to sport
P< 0.007
Our important finding
GRAPH SHOWING SIGNAL INTENSITY AT MID-SUBSTANCE
OF ACL GRAFT AT DIFFERENT TIME INTERVALS
0
1
2
3
4
5
6
2 MONTHS 6 MONTHS 12 MONTHS
TIME INTERVAL
SIGNAL INTENSITY(SNQ=Signal
Region of interest / Background
Signal)
Normal
Minimal Debridement

Minimal vv Standard debridement
1 year follow-up
MRI Results
Higher signal @ 2/12
….. “ faster ligamentisation”
Lower signal@ 6/12
…….“stronger,stiffer graft earlier ”
Clinical results
At 1 year no clinical difference??

Gohil et al 2007
Minimal (n=24) vv Standard (n=25)
single bundle hamstring graft
Trans tibial drilling
Endobutton and Intrafix
tensioned in extension
Run 4/12 Sport 9-12/12
Gohil S, Breidahl W, Annear PT (2007)
Anterior cruciate ligament reconstruction using autologous double hamstrings:
a comparison of standard versus minimal debridement techniques using MRI
to assess revascularisation. J Bone Joint Surg 89-B:1165–1171

Chart review (98%)
25 standard
23 minimal debridement
Clinical subjective data review (71%)
: 18 standard
: 17 minimal debridement.
Method
Minimal vv Standard Debridement
10 year follow-up

Statistical Analysis
Fisher’s exact test
– Chart Analysis.
– “Full Duties, No restrictions” data
Standard t-test.
Remaining clinical review

Disadvantages ?
Residual Cyclops lesions and impingement / LOE
Technically difficult
notch space management
poor bony landmark visualization
Equivocal clinical improvement ?

Gohil et al 2007
Single Bundle 4 Strand Hamstring Graft
Trans tibial drilling
Endobutton and Intrafix
Tensioned in extension
Run: 4/12 Sport: 9-12/12
Gohil S, Breidahl W, Annear PT (2007)
Anterior cruciate ligament reconstruction using autologous double hamstrings:
a comparison of standard versus minimal debridement techniques using MRI
to assess revascularisation.
J Bone Joint Surg 89-B:1165–1171
Remnant Preservation
n=24 Remnant Debridement
n=25

RESULTS
Two groups matched for :
Age
Sex
Acute vs chronic
Associated surgery
Meniscal injury
(13 normal / 17 minimal)
Chondroplasty
(3 in each group)

Results
Clinical data at 2, 6 and 12 month
Range of motion and Lachmans
MEAN ROM
2 MONTHS 6 MONTHS 12 MONTHS
MEAN VALUES N MD N MD N MD
EXTENSION 1.4 ° 0.8 ° 0.6 ° 0.7 ° 0.3 ° 0.5 °
FLEXION 113 ° 120 ° 130.7 ° 135.5 ° 138.5 ° 137.6 °
LACHMAN 3.1 mm 3.5mm 2.8mm 3.2mm 2.75mm 3.2mm

Results
Femoral tunnel placement
(Coronal plane)
All at 11 or 1 o’clock (except 4 patients)
4 vertical tunnels (12.30)
2 in “normal debridement” group
2 in “minimal debridement “ group

Results
Other MRI findings
“MRI” Cyclops lesions
13 MD group 9 in “normal” group
No correlation with loss of extension
Graft Impingement
1 patient in MD group
PCL signal change
Increased in both groups at 2 months
1patient had grade 1/2 PCL laxity at 1 year

1 year outcomes
(Gohil et al) RP RD
Knee extension
(mean)
- 0.3 degrees - 0.5 degrees
Vertical femoral
tunnel
2 patients 2 patients
MRI cyclops 13 9
Variables at 1 yr that explain 10 yr findings

A high central lateral
portal helps notch view

An accesory low medial portal
to drill femur and avoid remnant

All Remnant retained
Tibial targeting based on remnant anatyomy
Elbow jig tip placed 8mm behind
AMB (or single bundle) jig tip
L
8mm
Spared - ligamentum mucosum
- fat pad
-all stable tibial remnant
Remnant sparing technique

Minimal notch debridement
technique
Clear fat pad and ligamentum mucosum
Leave all tibial stump
Shave a small window at 1.30-2.00 (L) at the back of the
notch
Shave small 1cm area
1.30 O’clock 5mm off back wall
L
LEFT
Lateral
Femoral
Condyle

Graft sits within

Strengths:
Level 1 RCT
10 year follow-up
Chart analysis and clinical review
Low demand on resources
Substantial qualitative data obtained
Statistically significant for some outcomes

3 types
Remnant Preservation ACLR
Isolated bundle
reconstruction Complete ACLR
Retain intact bundle Repair remnant
To femur alongside graft
Place graft
within retained
remnant

Remnant Preservation ACLR
Isolated bundle
reconstruction Complete ACLR
Retain intact bundle Repair remnant
To femur alongside graft
Place graft
within remnant

Metanalysis of 6 level 1 studies
328 patients
RP had better Lysholm scores
Follow-up 6-36 months
No clear clinical advantage
. Tie K, Chen L, Hu D, Wang H.
The difference in clinical outcome of single-bundle anterior cruciate ligament
reconstructions with and without remnant preservation :
A meta-analysis. Knee. 2017;23(4):566-574

Metanalysis of comparative
studies
jung 2014
13 studies
Stability instramented laxity better in 2/9 studies
5/13 did IKDC no diff
Better ligamentization ½
Better proprioception ½ hong vv lee
2/2 less tunnel enlargement
LOE cyclops all no diff

Chart Analysis graft failure rate
graft failure times
reoperation rate
clinic revisit rate
Clinical/ email review
subjective outcome data
Method
10 year follow-up measures

Remnant
debridement
Remnant
preservation
P value
Graft failure 3 2 0.71
Contra-lateral acl injury 2 4 0.6602
Mean post-op time of
graft re-injury
11 months 49 months Small sample
Mean post-op time of
combined graft and
contralateral ACL injury
15 months 46 months P < 0.07
Chart review

Transtibial drilling
Aimed to retain
-fat pad
-ligamentum mucosum
Left as much stable remnant as
possible
Remnant Preservation ACLR
Complete ACLR
Place graft
within remnant

P= 0.7644
VAS Satisfaction
0-10 score
8.3
8.1
Remnant
Preservation
Standard
PROMs

Std Debridement Min Debridement
69.50%
70.00%
70.50%
71.00%
71.50%
72.00%
72.50%
P-value 1.0:
% Current Full Duties with no restriction
72.
71
Standard Remnant
Preservation
PROMs

Transtibial drilling
Aimed to retain
-fat pad
-ligamentum mucosum
Left as much stable remnant as
possible
Remnant Preservation ACLR
Complete ACLR
Place graft
within remnant

Gohil S et al (2007)
(n=49)
Remnant Preservation
n=24
1Year
Clinical and MRI graft signal study
Remnant Debridement
n=25
MRI SNQ
mid substance graft

Isolated bundle
reconstruction Complete ACLR
Retain intact bundle Repair remnant
To femur alongside graft
Place graft
within remnant
Future study ……… defining preserved remnant
RP Technique

Defining Preserved Remnant
in length
MRI volume
…….notch impingement vv biology
……..enhanced stability
……….mechanoreceptor health
Ammount
Anatomical attachment
Remnant age ( time to surgery)

Is the remnant preservation graft
biologically better?
10 year
post-op Graft
failures
combined
graft and
contral lateral
ACL injury
Time to
failure
(combined)
RP 2 6 46
Standard 3 5 15
P<0.07
Discussion

P-value 0.1058:
% Improvement - pre to post op
43
51
Standard Remnant
Preservation
PROMs

Gohil et al 2007
Higher graft signal at 2 months
Lower graft signal at 6 months
Remnant Preservation
n=24 Remnant Debridement
n=25
No clinical difference at 12 months