What is new in CrCl surgery in humans

Transcription

1 What is new in CrCl surgery in humans ESVOT meeting, Lodi, Italy September 12, 2015 Stephen Bresina, Sc.D. Kyon & Scyon Orthpoaedics

2 Failure Mechansim 30 % in USA due to contact (American Football) Non-contact failure - weight bearing foot is fixed on ground and upper body pivot causes rotation at knee joint

3 Epidemiology of ACL injuries ACL injuries per year ACL reconstructions per year Sweden England 30 per USA > (US Bancorp) (journals) Europe > (Giesink, Kyon Symposium) > New Zealand 36.9 per

4 ACL reconstruction Options Autograft Allograft Synthetic/prosthetic ligaments Ligament regeneration

5 Autografts possible sources Patellar tendon, Referred to as BPTB from the hamstring attachment to the tibia semitendenosus and gracilis tendons Quadriceps tendon Iliotibial band Tensor fascia lata Achilles tendon

6 Graft Requirements Match the strength and stiffness of the natural ACL as close as possible Immediate rigid fixation Healing of the graft fixation sites are optimal Accesible for harvesting and to minimize damage or weakness of the donor site No single graft source meets all of these requirements No consesus in literature on the optimal choice

7 Graft Fixation Match the strength and stiffness of the natural ACL as close as possible Immediate rigid fixation Healing of the graft fixation sites are optimal Accesible for harvesting and to minimize damage or weakness of the donor site Graft Slippage is problem of fixation Graft Elongation is a property of the graft material Both can lead to late instability

8 Autograft - Bone-Patellar Tendon-Bone (BPTB) patellar tendon grafts use the middle third of the tendon plugs of bone from the kneecap above and the tibia below.

9 (BPTB) Graft Gold Standard bone blocks pressed against tunnel with interference screws give good initial stability and ingrowth

10 Autograft - Hamstring tendons hamstring tendons (semitendinosus and gracilis) are taken as tendon only (no bone plugs) incision is made along the inside edge of the knee, just over where the hamstring tendons attach to the tibia the center part of the semitendinosus and gracilis tendons are removed. (sometimes only ST)

11 Autograft Hamstring Tendons the tendons are arranged into three or four strips. the strips are prepared to the correct length and stitched together to hold them in place Accufix GraftMaster from Smith and Nephew for graft preparation

12 Graft Strength (D. Gulick, J Sport Science & Med. 2002)

13 Graft Stiffness (D. Gulick, J Sport Science & Med. 2002)

14 Allografts Cadaveric source most common allografts used include the hamstring, patellar, and Achilles tendons no pain or scaring from a donor site shorter surgery time the tendon reconstruction is performed identical to that of the autografts autograft is considered to be more desirable during the first reconstruction allografts used more for ACL reconstruction revision risk of infection, or viral transmission (HIV, AIDS, etc)

15 Surgical Procedure Prepare knee for graft placement remnants of the original ligament are removed. intercondylar notch is enlarged so that nothing will rub on the graft (notchplasty) holes are drilled in the tibia and the femur to place the graft holes (tunnels) are placed so that the graft will run between the tibia and femur in the same direction as the original ACL

16 Surgical Procedure graft placement the graft is then pulled into position through the tunnels interference screws or staples are used to hold the graft inside the tunnels

17 Functional outcomes (Lohmander, )

18 OA 5 Year Post op follow-up report Sweden 50% of ACL reconstructions could be avoided and replaced by physiotherapy no increased risk of osteoarthritis or meniscal surgery if the ACL injury was treated with physiotherapy alone compared with surgical treatment no difference in patients experiences of function, activity level, quality of life, pain, symptoms or general health no difference in any outcome between those who were operated on straight away, those who were operated on later and those who did not have an operation at all Richard Frobell, Harald Roos, Ewa Roos, Frank W Roemer, Jonas Ranstam and Stefan Lohmander. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial BMJ 2013; 346

19 OA cont. 10 year follow-up study, 50 high level athletes (Meuffels, Br J Spor Med 2009) 48% radiographic OA in treated with ACL reconstruction 28% radiographic OA in knees treated without reconstruction No significant difference between groups 15 year follow-up randomised study, 100 patients (Meunier, Scand J Med Sci Sports, 2007) No differences in percentage of radiographic OA between surgical and non-surgical treatment

20 Improved techniques Single Bundle vs. Double Bundle (S. Kohl, CH Zeitschrift Sportmed, 2013)

21 Double Bundle Reproduces physiological structure smaller Anteromedial bundle tight in flexion larger posterolateral bundle tight in extension (

22 Double Bundle - Guidelines Measurement of the ACL insertion on the tibia > 18 mm requires DB to sufficiently restore ACL insertion site < 14 mm may not allow 2 tunnels to be drilled (Murawski, Cartilage, 2013)

23 Clinical Relevance - Double Bundle DB has theoretical advantages increased surgical complexity DB reconstruction does not result in clinically significant differences in KT-1000 arthrometer or pivot shift testing.source: Meta analysis resulted in 9 studies included from 97 MEDLINE references(meredick, AJSM, 2008) mixed results presented in literature with some showing superior knee stability with DB and others showing no difference (Murawski, Cartilage, 2013)

24 Synthetic Ligaments GoreTex, Leeds-Keio, historical Ligament Augmentation Reinforcement System - LARS Tricomponent graft Dynamic Anchoring Technique - Ligamys

25 Synthetic Ligaments Mascarenhas, MJM_2008

26 Synthetic Ligaments Leeds Keio Gore Tex

27 Synthetic Ligaments - LARS Ligament Augmentation Reinforcement System two bundles orientated clockwise or anticlockwise for right and left knees to mimic the natural ligament High strength UHMWPE fibers (Dyneema) N for 30 fibers N for 60 fibers N for 100 fibers

28 Synthetic Ligaments Ligamys (Mathys)

29 Synthetic Ligaments Ligamys (Mathys) the Ligamys implant provides a tight but elastic connection between the thighbone and the shinbone tunnels in the bones ensure that the polyethylene thread follows the natural path of the anterior cruciate ligament inside the joint the polyethylene thread is retained on the femur by the metal platelet and on the tibia by the monobloc with spring system

30 Synthetic Ligaments Ligamys (Mathys) the polyethylene thread is anchored in the monobloc with a precisely predetermined tension the tension is calculated to provide the cruciate ligament with the relief required for the rupture to heal at the same time the spring system gives enough free play to dynamically (elastically) respond to varying loads

31 Synthetic ligaments Tricomponent Graft (E.J. Cheng, Jtissue Eng. 2014)

32 Regeneration of Ligament Collagen gels or scaffold Loaded with stem cells

33 Regeneration of Ligament 4 week tensile testing

34 Future: improvements are certainly coming Long term results with surgical improvements still to come Arthroscopic approach Instrumentation (aiming devices, tensioning) Interference screw material (resorbable, bone inducing) Graft fixation improvements Graft location improvements High strength synthetic material with proper fixation