LARS PLC. PLC Augmentation and Reinforcement Surgical technique

Transcription

1 LARS PLC PLC Augmentation and Reinforcement Surgical technique

2 LARS PLC Contents Posterolateral corner pathology 3 LARS overview 4 LARS material overview 4 LARS general considerations 4 Indications 4 Contraindications 4 Surgical approach 5 Best practice guidelines 5 LARS anatomic PLC reconstruction technique summary 6 Anatomic reconstruction using LARS PPLY Drilling the tibial tunnel 8 2. Drilling the fibular tunnel 8 3. Passing the LARS ligament through the tibia 9 4. Tibial fixation 9 5. Passing the LARS ligament through the fibula Recreating the LCL Recreating the popliteus tendon Placement of the femoral tunnel Drilling the femoral tunnel Passing the LARS ligament through the femur Femoral fixation 13 Larson technique 14 A1. Drilling the fibular tunnel 14 A2. Passing the LARS ligament through the fibula 14 A3. Determining femoral tunnel placement 14 A4. Drilling the femoral tunnel 15 A5. Passing the LARS ligament through the femur 15 A6. Fixation 16 Rehabilitation guidelines 16 Ordering information 17 References 18 Corin would like to thank Mr David Houlihan-Burne and Mr Sam Church for their contribution to this surgical technique. 2

3 Posterolateral corner pathology Soft tissue structures of the posterolateral corner (PLC) of the knee are accepted as vital to varus, posterior and rotational stability of the knee. Isolated PLC injuries are rare, accounting for approximately 2% of all acute knee ligament injuries 1, but are often associated with ACL and PCL tears, or tibial plateau fractures. A study by LaPrade et al. reported PLC injuries in 11% of patients presenting with acute ACL tears 2. Unidentified or untreated PLC injuries can result in increased forces on the ACL and PCL and also early failure of reconstructions of these structures 3,4,5,6,7. Varus joint line opening in full extension and 30 flexion are good indicators of PLC injury but comparison should always be made to the contralateral leg. The dial test can be performed with the patient in the prone position to eliminate hip rotation. An external rotation force is applied to the foot at 30 of knee flexion and the patient is examined for increased posterolateral tibial rotation. An increase of 10 to 15 from the contralateral side denotes a positive test. The test is then repeated at 90. A further increase in rotation is indicative of a cruciate injury, while a decrease in rotation indicates an intact PCL 3. The posterolateral drawer test is performed with the patient positioned supine with the hip flexed 45 and the knee flexed 90. The foot is externally rotated 15 and a posterolateral rotation force is applied to the knee. A positive test demonstrates increased lateral tibial external rotation and posterior translation when compared to the opposite side. In multiligament injuries, there is often a deficit of suitable autograft to allow full surgical reconstruction of the affected structures. As a synthetic scaffold LARS is designed to provide initial stability, allowing biological healing to take place, while eliminating post-operative elongation. LARS PLC Stability Versatility Recovery Responsible Innovation 3

4 LARS PLC LARS overview LARS material overview LARS (Ligament Augmentation & Reconstruction System) is a system of synthetic scaffolds intended for use in general surgical procedures for reinforcement of soft tissue where weakness exists, suitable for specified applications in the body. The LARS scaffold material is comprised of polyethylene terephthalate (PET-Polyester) which has been used in medical devices since the early 1940s. The LARS material (PET) is woven using an inverse warp knitting technique, providing resistance to weave loosening and elongation. Each scaffold configuration has been designed with the optimal shape, size and mechanical property for the specific application in the body. This surgical technique guide has been developed to detail the use of LARS scaffolds in posterolateral corner reconstruction. Indications PLC reconstruction surgery is indicated in active patients with grade III (complete disruption) injuries or grade II with functional instability and/or concomitant cruciate injury where ACL, PCL and/or medial side reconstruction are planned. PLC injury can be diagnosed by varus joint line opening in full extension and 30 flexion and also by a positive dial test when compared to the contralateral leg. In the context of posterolateral corner instability, LARS is used in reconstructing or reinforcing the damaged lateral collateral ligaments and the popliteus tendon. In acute circumstances the ruptured soft tissue stumps should be maintained where possible and the LARS acts as a splint to aid healing. In chronic cases LARS can be used as an augment to biological repair. In multiligament reconstruction procedures, the cruciate ligaments are reconstructed first, prior to addressing the posterolateral pathology. LARS general considerations There are certain factors that must be considered with the use of the LARS scaffolds. Being a non-biological material, LARS does not have the elongation properties of auto or allografts. Therefore, it is important to fix the scaffold at its longest length throughout the Range of Motion (RoM) to avoid impingement or inhibition of movement. Furthermore, it is important to use non-absorbable sutures to secure the scaffold material in place. For optimal results, repairs with LARS scaffolds should be done as acutely as possible. Contraindications PLC reconstruction surgery should not be carried out in patients with grade I or II injuries where there is no functional instability. Patients with chronic PLC deficiency with significant varus malalignment should be considered for valgus-producing osteotomy prior to PLC reconstruction. In patients with concomitant degenerative arthritis, the benefits of total knee replacement may outweigh the benefits of soft tissue reconstruction. LARS ligaments are contraindicated in patients with: Active or latent infection Decreased vascularity Pathologic bone or soft tissue conditions that would prevent secure fixation The device is contraindicated for use in any patient with psychiatric or neurologic conditions, who is unwilling or incapable of following post-operative care instructions. 4

5 Surgical approach With the patient lying supine and the knee flexed to 90, a skin incision is made from Gerdy s tubercle to the lateral epicondyle, then in-line with the ITB to approximately 6-8cm proximal to the joint line. The incision should be made in the anterior third of the lateral thigh to allow access to the LCL origin. Using blunt dissection, identify the common peroneal nerve to prevent accidental damage: Usually 2cm distal to the fibular head, or Just posterior to the biceps femoris musculo-tendinous junction Pass a loop of tape around it to allow continued identification and isolation. Avoid traction on the nerve. The position of the common peroneal nerve can change dramatically following injury to the posterolateral area of the knee. Care must be taken at all times. Access the posterior tibia via the triangle formed between the biceps femoris tendon, common peroneal nerve and the lateral head of gastrocnemius, and subperiosteally separate the lateral head of gastrocnemius and soleus muscles from the posterior tibia between the posterior head of the fibula and the PCL tibial insertion. PPLY 100 (product code: ) leader threads free fibres leader thread The LARS PPLY 100 can withstand forces up to 4000N LAC 30 CK (product code: ) leader thread leader thread Best practice guidelines As a third generation synthetic ligament, LARS has demonstrated excellent clinical results in both intra- and extra-articular applications over the last 20 years of clinical application. However, as a synthetic material it is vital that the ligament is used only in suitable indications and following a well defined surgical technique to ensure that optimal patient function, long-term outcomes and satisfaction are achieved. Bony tunnels must be placed so as to reduce the elastic demand on the LARS ligament. Tunnel diameters must correspond to the specific reference for each ligament. Using the smallest tunnels possible will minimise ligament micromotion and fluid ingress to encourage bony ingrowth. If using a LARS option with free fibres, the free fibres should not enter the bony tunnels when fixed in place. 1-2mm of the woven section of the LARS should be visible outside the posterior of the tibial tunnel to minimise wear of the fibres on the tunnel entrance. LARS ligaments tolerate a maximum stretch of 9% so to avoid over-tensioning of the ligament it must be fixed at its longest length. Over-tensioning of the LARS can lead to restriction of full RoM and wear of the fibres. Ligaments must be fixed in bone tunnels with non-resorbable LARS blunt threaded interference screws at least 1mm larger than the bone tunnel diameter and longest length permissible, depending on tunnel length. The LARS LAC 30 CK can withstand forces up to 1500N Fixation in bony tunnels should be completed by blunt threaded, titanium LARS interference screws at least 1mm larger than the tunnel diameter, and maximum length permitted by the tunnel length. Responsible Innovation 5

6 LARS PLC LARS anatomic PLC reconstruction technique summary 6 1. Drilling the tibial tunnel 2. Drilling the fibular tunnel 3. Passing the LARS ligament through the tibia 7. Recreating the popliteus tendon 8. Placement of the femoral tunnel 9. Drilling the femoral tunnel

7 4. Tibial fixation 5. Passing the LARS ligament through the fibula 10. Passing the LARS ligament through the femur 11. Femoral fixation 6. Recreating the LCL Responsible Innovation 7

8 LARS PLC Anatomic reconstruction using LARS PPLY Drilling the tibial tunnel The anterior start point for the tibial tunnel is located on the medial side of the tibia, distal to the start point for an ACL reconstruction tibial tunnel. The LARS PLC aimer jig should be used with the flat spade end located 3cm inferior to the posterior tibial plateau and 1cm medial to the posterior fibular head. Drill through the drill guide with the non-cannulated, spike tipped 7.5mm drill until the positive stop is reached. Remove the spike tipped drill and complete the tunnel using the 7.5mm cannulated drill. Prior to use ensure that the spike tipped 7.5mm drill stops inside the distal spade tip of the jig. With the LARS PLC drill guide still in place, use the curved wire loop passer cannula to pass a flexible wire loop through the tibial tunnel so that the looped end exits the posterior tibia. This will allow passing of the LARS ligament later. Note: Alternatively the tibial tunnel can be created by drilling free-hand with a sharp K-wire followed by a 7.5mm cannulated drill. Care must be taken to avoid over-drilling and causing damage to the posterior tissues. 2. Drilling the fibular tunnel Drill a sharp tipped K-wire through the fibula at the widest part of the fibular head from anterolateral to posteromedial, exiting at the insertion of the popliteofibular ligament (PFL). Over-drill with a 5 or 6mm cannulated drill bit to create a tunnel approximately 25mm long. Aim medial and slightly distal, parallel to the tibia through the widest part of the fibula. 8

9 Using the curved wire loop passer cannula, pass a flexible wire loop through the fibula from anterior to posterior. Use this wire loop to pull a second flexible wire loop back through the fibula so that the looped end exits the anterior fibula. 3. Passing the LARS ligament through the tibia Use the flexible wire loop through the tibia to pull the single, thicker limb of the LARS PPLY 100 ligament through the tibia from posterior to anterior. When in the correct position, 2mm of the woven, intraosseous section of the LARS should be outside of the posterior tibia. The free fibre section of the LARS ligament should not enter the tibial tunnel to prevent fraying. 4. Tibial fixation Secure the LARS in place using a 9 x 30mm LARS interference screw inserted anterior to posterior. The screw head should sit flush with the anterior cortex. Do not over-insert the fixation screw as cortical fixation is essential. The head of the screw should sit flush with the bone cortex. Responsible Innovation 9

10 LARS PLC 5. Passing the LARS ligament through the fibula One of the thinner limbs of the LARS PPLY 100 ligament from the posterior tibia is brought around the lateral side of the fibula and then pulled back through the fibular tunnel from anterior to posterior using the flexible wire loop positioned earlier. 6. Recreating the LCL The LARS ligament limb is then passed from the posterior fibula, underneath the iliotibial band (ITB) up to the lateral epicondyle. 10

11 7. Recreating the popliteus tendon The second thin LARS limb is retrieved from the posterior tibial tunnel exit and passed under the ITB/ musculo-tendinous junction directly up to the lateral epicondyle. 8. Placement of the femoral tunnel Clearly identify the femoral insertion point, usually at the lateral femoral epicondyle. Split the iliotibial band (ITB) in line with its fibres to expose the lateral epicondyle. Note: Image intensification can be used to aid identification of the femoral tunnel position. Drill through the femur, lateral to medial, with a sharp tipped 2mm K-wire. Starting at the lateral femoral epicondyle, aim anterior, medial and proximal to reduce the risk of impinging on other tunnels required for ACL reconstruction procedures and to prevent damage to the MCL. Once the K-wire is correctly positioned, check isometry by wrapping each of the thinner LARS limbs over the K-wire and flex/extend the knee through full RoM. There should be minimal change in tension of the LARS. Responsible Innovation 11

12 LARS PLC 9. Drilling the femoral tunnel Over-drill with a 7.5mm cannulated drill bit to breach both lateral and medial cortex. Remove the drill leaving the K-wire in place and insert the long narrow tube over the K-wire. Pass a flexible wire loop through the tube so that the looped end exits the lateral end of the tunnel. Replace the sharp K-wire with a blunt screw guidewire and remove the tube leaving the wire loop and guidewire in place. Note: It is also possible to insert the blunt screw guidewire into the femoral tunnel after the LARS ligament has been passed through the femur. 12

13 10. Passing the LARS ligament through the femur Using the flexible wire loop, draw the leader threads from the two thinner limbs of the PPLY 100 LARS through the femoral tunnel from lateral to medial. Making sure that the screw guidewire remains in place, pull both LARS ligament limbs through the femoral tunnel. 11. Femoral fixation Each limb of the LARS should be individually tensioned and the knee put through full RoM. Avoid over-tensioning of the LARS as this could restrict RoM. Note: The knee has a degree of natural varus laxity at 30 and 60 of flexion. Tension should be adjusted to mimic the contralateral knee. With the knee in full extension and neutral rotation, securely fix the LARS in the femoral tunnel using a 9 x 30mm LARS interference screw inserted over the blunt guidewire. Responsible Innovation 13

14 LARS PLC Larson technique Alternatively a LARS LAC 30 ligament can be used in a modified Larson s technique. A1. Drilling the fibular tunnel Drill a sharp K-wire through the fibula at the widest part of the fibular head from anterolateral to posteromedial. Over-drill with a 4.5mm cannulated drill bit to create a tunnel approximately 25mm long. Using the curved wire loop passer cannula, pass a flexible wire loop through the fibula. A2. Passing the LARS ligament through the fibula Use the flexible wire loop to pull the leader sutures of the LAC 30 LARS through the fibula. Pull the LARS LAC 30 through the fibula until it is centred. The LARS ligament should be secured in the fibular tunnel using a 5.2 x 15 or 20mm screw inserted over a blunt screw guidewire. A3. Determining femoral tunnel placement Identify and clear the lateral femoral epicondyle of soft tissue. Drill through the femur, lateral to medial, with a sharp tipped 2mm K-wire. Starting at the lateral femoral epicondyle, aim anterior, medial and proximal to reduce the risk of impinging on other tunnels required for ACL reconstruction procedures and to prevent damage to the MCL. To determine graft isometry, wrap the LARS ligaments around the K-wire exiting the lateral condyle and put knee through full RoM. There should be minimum change in tension throughout the RoM. 14

15 A4. Drilling the femoral tunnel Drill with a 7mm cannulated drill bit over the K-wire to breach both lateral and medial cortex. Remove the drill leaving the K-wire in place and insert the long narrow tube over the K-wire. Pass a flexible wire loop through the tube so that the looped end exits the lateral end of the tunnel. Replace the sharp K-wire with a blunt screw guidewire and remove the tube leaving the wire loop and guidewire in place. Note: It is also possible to insert the blunt screw guidewire into the femoral tunnel after the LARS ligament has been passed through the femur. A5. P assing the LARS ligament through the femur The two limbs of the LARS ligament are passed underneath the ITB up to the lateral epicondyle. Using the flexible wire loop, draw the leader threads from the two ends of the LAC 30 LARS through the femoral tunnel from lateral to medial. Making sure that the screw guidewire remains in place, pull both LARS ligament limbs through the femoral tunnel. Responsible Innovation 15

16 LARS PLC Rehabilitation guidelines The pace of rehabilitation is individual to the patient and should be tailored to their demands, response to therapy and their wound healing. Return to activity should only be recommended when both objective and subjective outcomes are satisfactory. Recommended post-operative care following isolated PLC reconstruction with LARS : Hinged brace allowing full RoM for six weeks A6. Fixation Avoid over-tensioning of the LARS as this could restrict RoM. Note: The knee has a degree of natural varus laxity at 30 and 60 of flexion. Tension should be adjusted to mimic the contralateral knee. With the knee flexed to 70 and slight internal rotation, securely fix the LARS ligament in the femoral tunnel using an 8 x 30mm LARS interference screw inserted over the blunt guidewire. Do not over-insert the fixation screw as cortical fixation is essential. The head of the screw should sit flush with the bone cortex. Full weight-bearing (in normal knee alignment) and isometric quadriceps exercises to be started the day after surgery to recover full RoM and muscle strength Progress to sports specific exercises at approximately four to five months within limits of pain and swelling Return to work will depend on the type of work and the individual patients recovery time Participation in competitive sport is dependent on the patients individual recovery and should only be recommended once the patient has regained full proprioception and muscle control Note: Where the posterolateral corner reconstruction is completed as part of a multiligament reconstruction, the rehabilitation will need to be altered to reflect the individual patients requirements depending on the other ligament involved. LARS ligaments are strong immediately after implantation, therefore there may be a temptation for a patient to be less diligent with physiotherapy. Physiotherapy is essential to the longevity of the LARS. 16

17 Ordering information LARS posterolateral corner ligaments Code Product description LARS PPLY LAC 30 CK LARS blunt threaded interference screws and staples Code Size x 15mm x 15mm x 30mm x 30mm x 30mm LARS ligament staple 8 x 20mm LARS mulitligament knee instrument set Code Product description mm cannulated drill mm cannulated drill mm cannulated drill mm cannulated drill Cannulated drill bit 6 x 200 int dia 2.2mm - U Cannulated drill bit 7.5 x 250 int dia 2.2mm - U Drill bit 3.5 x 150mm Drill bit dia. 6 x 200mm with spike & stopper D01011 & U Drill bit dia. 7.5 x 200mm with spike & stopper D21010 & U Drill bit guide int. dia. 10mm - D Drill bit guide int. dia. 8mm - D Drilling guide dia. 12mm - D Drilling guide dia. 6mm - D Drilling guide dia. 7.5mm - D Femoral hook - C Guide - B K-wire dia. 2 x 250mm 2 trocar ends - U K-wire dia. 2 x 250mm blunt ends - U K-wire dia. 3 x 250mm 1 trocar end for guide s tibial fixation - U Ligament cutter - ACPL02 Code Product description Ligament traction - retractor handle - U Postero-externe hook - C Screwdriver - ATVS Staple extractor - AEAG Staple impactor - AIAG Telescopic tube L 140mm - retractor - U Telescopic tube L 160mm - U Telescopic tube L 180mm - U Telescopic tube L 200mm - U Hook wire-passer (PPLY) - D Wire loop - U x Wire loop passing cannula for PLI (6mm) - D Curved wire-passer cannula - D mm reduction for curved wire-passer cannula - D21012 Box details A Tray - D B Tray - D Outer box Responsible Innovation 17

18 LARS PLC References 1. Delee JC, Riley MB, Rockwood CA Jr. Acute posterolateral rotatory instability of the knee. American Journal of Sports Medicine. 1983;11: Laprade RF, Hamilton CD, Engebretsen L. Treatment of acute and chronic combined anterior cruciate ligament and posterolateral knee ligament injuries. Sports Medicine and Arthroscopy Review. 1997;5: Scheck RC Jr., ed. Multiple Ligamentous Injuries of the Knee. Rosemont, IL: American Academy of Orthopaedic Surgeons; Fleming RE Jr., Blatz DJ, McCarroll JR. Posterior problems in the knee: posterior cruciate insufficiency and the posterolateral rotatory insufficiency. American Journal of Sports Medicine. 1981;9: Hughston JC, Norwood LA Jr. The posterolateral drawer test and external rotational recurvatum test for posterolateral rotatory instability of the knee. Clinical Orthopaedics and Related Research. 1980;147: LaPrade RF, Resig S, Wentorf F, et al. The effects of grade III posterolateral knee complex injuries on anterior cruciate ligament graft force: a biomechanical analysis. American Journal of Sports Medicine. 1999;27: LaPrade RF, Muench C, Wentorf F, et al. The effect of injury to the posterolateral structures of the knee on force in a posterior cruciate ligament graft: a biomechanical study American Journal of Sports Medicine. 2002;30:

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20 Distributed by Corin The Corinium Centre Cirencester, GL7 1YJ, UK t: +44 (0) f: +44 (0) e: Manufactured by LARS 5 rue de la Fontaine Arc sur Tille, France t: +33 (0) f: +33 (0) e: info@lars-ligaments.com 2015 Corin P No I1349 Rev0 09/2015 ECR 145