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

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 1 - 16% 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) 29.3-37.5 83 (42.1) 35.2-49.0 30 (29.4) 20.6-38.3 33 (38.8) 28.5-49.2 22 (18.5) 11.5-25.5 Training and/or modified competition 169 (33.6) 29.5-37.7 69 (35.0) 28.4-41.7 34 (33.3) 24.2-42.5 24 (28.2) 18.7-37.8 36 (30.3) 22.0-38.5 No attempt 166 (33.0) 28.9-37.1 41 (20.8) 15.1-26.5 37 (36.3) 26.9-45.6 28 (32.9) 23.0 -42.9 60 (50.4) 41.4-59.4 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 36.7 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)

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.

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: 1730 Nt LARS AC-100: 4700 Nt AC-120: 5000 Nt

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

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

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%

Status of knee lesions Associated meniscus and ligamentous lesions Chondral lesions

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

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 1.5-2.5 weeks post-OP Jogging progressive training from 4-6 weeks post-OP Return to vigorous activities sports practiced 8-12 weeks post-OP

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

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

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)

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 -2.5 points There is some time-related decrease in IKDC, however the change is not significant

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

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

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

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

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

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….)

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 .....

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

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

Thank you for your attention