1. Treatment of unstable knee ACL deficiency using the new generation LARS artificial ligament Long-term follow-up of 162 operated knees in 155 patients
Maj. Gen. Greg. Papadopoulos MD, Lt. Col Sp. Darmanis MD, D. Kiatos PHT Orthopedic and Trauma Department Athens Military Hospital and Iaso General Hospital Athens, Greece Iasimo Rehabilitation Centre, Athens, Greece

2. Background
Traditional ACL-R has achieved good-to-excellent results in only 60% of patients Fu et al 2008
63% of ACLRs returned to their pre-injury activity level after 12 months
44% returned to competitive sport at 36.7 months post-op Ardern & Feller et al 2011
Mid (≤ 96months) to long -term (15 yrs) failure rates quoted at between % for autografts Pinczewski 2011, Magnusson 2011, Li 2010
Table 1: Sports Attempt at 12 Months for Most Commonly Played Sports (CI, confidence interval)
Seasonal Sports
Year-round Sports
Overall
Australian Rules Football
Soccer
Basketball
Netball n
503
197
102 85
119
Full competition
n (%)
95% CI
168 (33.4)
83 (42.1)
30 (29.4)
33 (38.8)
22 (18.5)
Training and/or modified competition
169 (33.6)
69 (35.0)
34 (33.3)
24 (28.2)
36 (30.3)
No attempt
166 (33.0)
41 (20.8)
37 (36.3)
28 (32.9)
60 (50.4)
I wanted to start by giving you the rationale for our study on LARS ligaments. In the mid 1990‘s we looked very closely at our HT results and those of other renowned centres around the world. Like other centres we were not completely happy with our existing graft choice – a good proportion of patients were not returning to their pre-injury level of sport, we still saw donor site morbidity as an issue with our patients. But we‘re not the only ones -
Freddie Fu‘s group have shown that traditional ACLR achieved good to excellent results in only 60% patients.
Looking at athletes in particular, Arden and Feller reported that only 44% patients returned to pre-injury level of function at months post op. In fact, in Australian Rules football :
Only 42.1% of players returned to full competition after 1 year
33% of players took part in training and/or modified competition after one year
20.8% of player made no attempt after 1 year
Furthermore, the AFL Injury Report published in 2010 reported a 23.5% ACL rupture rate in 2008.
Looking at mid to long term failure rates studies have shown variable results ranging anything between 1-16% (the latter was long term follow up by Leo Pinczewski’s group in Sydney)

3. Background
Over 78% patients experience donor site pain with HT at up to 3 yrs post-op
Between 3-27% HT strength deficits compared with non-operated side Feller et al 2011
Incomplete graft ligamentisation at up to 2 years after ACLR Janssen 2011, Claes 2011
Autologous grafts approached only 50–60% of the intact ACL failure strength at up to 12 mnths in sheep studies Scheffler 2005, 2008
Table 2. Clinical Evaluation Data
Characteristic
ST-G ST
IKDC subjective knee form score [mean ± SD (range)]
91.6 ± 8.1 (67 to 100)
94.4 ± 3.6 (85 to 100)
Side-to-side difference in knee laxity [mean ± SD (range)] (mm)
1.0 ± 2.8 (-7 to 5)
1.4 ± 2.9 (-5 to 5)
Postoperative hamstring pain (yes:no)
18:12
11:9
Side-to-side difference in active knee range of motion [mean ± SD (range)] (°)
2.3 ± 7.8 (-17 to 17)
24 ± 4.9 (-7 to 11)
Side-to-side difference in passive knee range of motion [mean ± SD (range)] (°)
1.9 ± 5.1 (-10 to 12)
3.0 ± 4.6 (-4 to 11)
Abbreviation: IKDC, International Knee Documentation Committee
We all know that despite the good results seen in autogenous reconstructions donor site morbidity is still an unsolved problem. In fact Arden et al showed that over 78% of patients demonstrated donor site pain with HT at up to 3 yrs follow up with a strength deficit of 27% compared with the non operated side.
In addition several studies are now questioning the time of completion of an autogenous graft ligamentisation process and Scheffler et al showed that autogenous implants approached only 50-60% of the intact ACL failure strength at up to 12 months post – op.
We understand that more than 3000 LARS ACL ligaments have been implanted in Australia and would like to thank the AKS for giving us the opportunity to present our results on this new generation synthetic ligament.

4. Why LARS? Avoids donor site morbidity or any other iatrogenic injury
Provides the possibility of natural ligament healing and early proprioception Murray 2011, Ahn 2011
Permits early rehabilitation leading to a faster return to work and sport
What is LARS?
Soft tissue internal fixator – scaffold type
PET (polyethylene terephthalate) with unique,
pre-twisted ‘free fibre’ design
Human ACL: Nt
LARS AC-100: Nt
AC-120: Nt

5. Study objectives & design
To report long-term functional follow-up of LARS ligaments in patients with an unstable knee and ACL deficiency
Study design
Monocenter prospective case-series
Independant, blinded data analysis by AO foundation
Follow-up examinations at upto 14 yrs (Average follow up 11 yrs)
Lachman - Noulis test
Pivot shift test
IKDC subjective

6. Patients Eligibility criteria
Patient with mature skeleton
Unstable knee with ACL deficiency
Treated with LARS by same surgeon (Dr Papadopoulos)
Standardized rehabilitation program (same Center)
Consented to long term follow up
Exclusion: complicated ligament injuries, dislocation or fractures, non-compliant patients
8-year enrollment period: Jan 1996 to Dec 2003
155 patients (162 knees)
Male:female = 123:32
Mean age = 38 years (range 15-68)
Side = 76 R, 72 L, 7 R+L

7. Injury characteristics
ACL stump classification
 Grade I II
III IV
ACL stump
Plastic deformation
Attached to PCL
Degenerated or attached to PCL
Complete degeneration
Anatomy
Intact
Torn
Length of the stump
Normal
Approx. 2/3
Approx. 1/2
Around ¼ or nothing (empty notch)
ACL ruptures
Total
Acute 17 41 4
69 43%
Anatomy 19 51 23
93 57%

8. Status of knee lesions Associated meniscus and ligamentous lesions
Chondral lesions

9. Operation technique Notchplasty = 18%
Recommended LARS technique followed
Preservation of stump where possible
No tension philosophy

10. Rehabilitation program
No brace post-operative (OP)
Immediate active quadriceps exercises
Immediate full weight bearing
CPM started on 2nd–3rd post-OP day
Normal walking weeks post-OP
Jogging progressive training from 4-6 weeks post-OP
Return to vigorous activities sports practiced 8-12 weeks post-OP

11. Results: Lachman-Noulis
Is this KT2000? Pre op and short term data? Is there any statistical difference?
No change in Lachman- Noulis test results over time, with up to 14 years FU
Each of the 162 knees were evaluated twice 2 years apart

12. Results: Pivot Shift
Pre op and short term data? Is there any statistical difference?
No change in Pivot Shift test results over time, with up to 14 years FU
Each of the 162 knees were evaluated twice 2 years apart

13. Results: IKDC
Pre op and short term data? Is there any statistical difference?
No overall significant change in IKDC score over time, with up to 14 years FU
Each of the 162 knees were evaluated twice 2 years apart (mixed model with repeated measure)

14. Results: IKDC adjusted for age
<=30
>30-40
>40
Pre op and short term data? Is there any statistical difference? P values?
There is a significant age effect :
Patients in the older group have lower mean IKDC than younger patients by points
There is some time-related decrease in IKDC, however the change is not significant

15. Results*: Knee pain during daily activity
5 - I have no pain in my knee.
4 - I have some pain in my knee but
this does not affect my daily activities.
3 - The pain affects my daily activities a little.
2 - The pain affects my daily activities moderately.
1 - The pain affects my daily activities a lot.
0 - The pain in my knee is severe. I can’t do my
daily activities.
*at final follow up time point

16. Results*: Knee stiffness during daily activity
5 - I have no stiffness in my knee.
4 - I have some stiffness in my knee but this does
not affect my daily activities.
3 - The stiffness in my knee affects my daily
activities a little.
2 - The stiffness in my knee affects my daily
activities moderately.
1 - The stiffness in my knee affects my daily
activities a lot.
0 - The stiffness in my knee does not allow
me to do my daily activities.
*at final follow up time point

17. Results*: Knee stability Noyes Personal Questionaire
20 - I have no giving way sign.
16 - I feel my knee unstable when I participate in
contact sports or do heavy work.
12 - I feel my knee unstable when I go jogging, which
restricts my sports activities or heavy work.
8 - I feel my knee unstable and I cannot participate
in sports.
- I often have giving way sign even when I walk.
0 - I have a big problem of stability when I must turn
or suddenly change direction.
*at final follow up time point

18. Results*: Knee activity level Noyes Personal Questionaire
20 - I have no restrictions.
I have a normal knee.
I can participate in contact sports.
16 - I participate in sports but with lower demands.
12 - I can do weekend sports with some symptoms.
8 - I cannot participate in sports at all.
Only jogging with symptoms.
4 - I have problems in my daily activities.
0 - I have severe problems in my
daily activities.
*at final follow up time point

19. Results*: Edema Noyes Personal Questionaire
10 - I have no edema in my knee. 8 - My knee is edematous from time to time when I participate in competitive sports or do heavy work. 6 - My knee is edematous after sports or moderate work. 4 - The edema limits my sports activities more than 4 times a year. 2 - My knee is edematous after running and the edema disappears after relaxing. 0 - My knee is edematous even when I walk and this remains after relaxing
*at final follow up time point

20. Revisions Minor complications Overall failure rate: 5.5% (9 Knees)
2 knees, 1.2% due to graft rupture (technical error)
3 knees, 1.8% due to persisting joint instability following trauma (re-tightening )
4 knees, 2.5% due to new trauma to the knee
Revised to:
Autogenous (3)
LARS (2)
Stand by (1)
Mini revision (3)
Minor complications
Superficial infection in the tibial portal – 3 knees, 1.8%
Lack of extension – 2 knees, 1.2%
Staple removal – 2 knees, 1.2%
0% synovitis
We also noticed that our results in patients with stump grade I-III was superior to those with stump grade IV. In addition, we found our patients with LARS were returning to activity at a shorter time period compared to our previous HT series by……..% (or average number of days….)

21. Revisions Analysis of a failure case
We found revision of a LARS to be a simple procedure
Remove all fixation
Apply a very strong clamp applying mild traction
If the ligament wont strip out, pass a blunt K wire into tunnel, drill over with 4.5mm drill at low speed
We sent one of our failed grafts for .....

22. Discussion
In our centre, LARS ACL has demonstrated excellent patient outcomes at an average follow up of 11 yrs
These failure rates are comparable to published HT and PT results at the same average follow up interval Pinczewski 2007 Wipfler 2011
Acute cases of ACL injury and those of chronic laxities with well- vascularised ACL-stump are the best indications to use the LARS ligament
Weaknesses: No radiographic follow up, further objective/subjective testing could have been included in this study

23. Conclusions
LARS has not exhibited high rates of complications associated with previous synthetics
LARS avoids donor site complications associated with autografts
Does not “burn any bridges” for possible revision surgery
Provides the possibility of natural ligament healing and early proprioception Murray 2011, Ahn 2011
Permits early rehabilitation leading to a faster return to work and sport

24. Thank you for your attention