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Methods and devices for graft fixation in anterior cruciate ligament reconstruction

  1. Chao Zeng,
  2. Guanghua Lei*,
  3. Shuguang Gao,
  4. Wei Luo

Editorial Group: Cochrane Bone, Joint and Muscle Trauma Group

Published Online: 3 SEP 2013

DOI: 10.1002/14651858.CD010730


How to Cite

Zeng C, Lei G, Gao S, Luo W. Methods and devices for graft fixation in anterior cruciate ligament reconstruction (Protocol). Cochrane Database of Systematic Reviews 2013, Issue 9. Art. No.: CD010730. DOI: 10.1002/14651858.CD010730.

Author Information

  1. Xiangya Hospital, Central South University, Department of Orthopaedics, Changsha, Hunan, China

*Guanghua Lei, Department of Orthopaedics, Xiangya Hospital, Central South University, #87 Xiangya Road, Changsha, Hunan, 410008, China. 9640lgh@sina.cn.

Publication History

  1. Publication Status: New
  2. Published Online: 3 SEP 2013

SEARCH

 
Table 1. List of ACL graft fixation devices identified from a recent literature search (22/05/2013)

NameDescription

Aperfix systemThe Aperfix (Cayenne Ltd) which was introduced in 2009 is a relatively new implant system. It is an all-inside system, requiring no cross pins or additional morbidity to the distal thigh, and aims to provide strong fixation of soft tissue grafts with circumferential aperture compression. This implant is made from polyetheretherketone (PEEK), which is a nonabsorbable, radiolucent material that causes no inflammatory response.

Bone mulch screwThe Bone mulch screw (Arthrotek Ltd) was introduced in 2003 for graft fixation in femoral side. It consists of an outer screw (including a threaded body and an outwardly extending nose portion which provides a mechanical fixation point by functioning as a post within the femoral tunnel) and an inner screw, introduced through the lateral femoral condyle. A hamstring graft is looped around this post, mechanically fixing one end of the graft.

Bone plugPress-fit bone plug fixation consists of a xenogenic spongiosa cylinder (Tubobone Ltd) (length: 30 mm, diameter: to match the diameter of the tibial tunnel) is inserted into the tibial tunnel, and a pusher is used to advance the cylinder to the proximal end of the tibial tunnel.

Button (Endobutton)The Endobutton (Smith & Nephew Ltd) was introduced in 1995 for graft fixation in anterior cruciate ligament reconstruction. The implant, which is widely used for fixation of quadruple hamstring grafts, is relatively cheap and consists of a suture loop and metal plate. The point of fixation is some distance from the joint. Theoretical advantages of this implant are due to a suspension mechanism and include reduced tunnel widening.

Button (Endobutton-CL)The Endobutton-CL (continuous loop) (Acufex or Smith & Nephew Ltd) was introduced in 2003 to solve the problems caused by the Endobutton, such as 'bungee effect' which could contribute to tunnel widening. The stiffer and slippage-free Endobutton-CL implant, therefore, seems to have created a more favourable biomechanical environment, resulting in less tunnel widening.

Button (Endobutton-CL-BTB)The Endobutton-CL-BTB (Smith & Nephew Ltd) was introduced in 2010 for graft fixation in anterior cruciate ligament reconstruction. The implant is composed of an Endobutton and 2 thin continuous polyester loops which are thinner than the loop installed in Endobutton-CL. A decrease in stiffness is considered to be one of the theoretical disadvantages of this system. A theoretical advantage of this implant, which can be used to fix the hamstring tendon graft, includes reducing operation time because the assistant surgeon can start fashioning the hybrid graft immediately after tendon harvest. In addition, the system comprises long and short loops, and can therefore be attached easily to the closed loop, which can also shorten operation time.

Button (flip-button or FlippTack)The flip-button (Karl Storz Ltd) was introduced in 2011 for graft fixation in cruciate ligament reconstruction. The tendons are fixed to this cortical fixation with a double-looped 1 mm Ethibond cord and 6 direction-changing knots.

Button (Retrobutton)The Retrobutton (Arthrex Ltd) was introduced in 2008 for graft fixation in anterior cruciate ligament reconstruction. This implant consists of a flat, 2.5 x 12 mm titanium button with an ultra high-molecular weight polyethylene loop. The loop is continuous, and its portion opposite the button is tripartite.

Button (TightRope RT)The TightRope RT (Arthrex Ltd) was introduced in 2013 for graft fixation in anterior cruciate ligament reconstruction. This implant has adjustable length loops that are tightened intraoperatively.

Button (ToggleLoc)The ToggleLoc (Biomet Ltd) was introduced in 2009 for graft fixation in anterior cruciate ligament reconstruction. The implant is a rectangular titanium rod that uses a suture sling (ZipLoop) to pass the tendon through the bone tunnel once the implant is in place on the cortical bone. This suspensory fixation device aims to provide adequate maximum pullout strength and minimise micromotion because of improved loop material characteristics.

Button (XO Button)The XO Button (ConMed Linvatec Ltd) was introduced in 2010 for fixation of the graft in anterior cruciate ligament reconstruction on the femoral side. This device consists of a metal component that sits on the lateral metaphyseal cortex and incorporates a prestretched continuous graft suspension loop.

CentraLocThe CentraLoc device (Arthrotek Ltd) was introduced in 2007 for soft tissue graft fixation in anterior cruciate ligament reconstruction on the tibial side. This device, which consists of a CentraLoc screw (bicortical screw) and a large “clover” washer with fins, aims to allow circumferential healing of the graft while enabling high cyclic loading.

Cross pin system

(Bilok ST)
The Bilok ST technique (Biocomposites or ArthroCare Ltd) was introduced in 2005 for graft fixation in anterior cruciate ligament reconstruction. This transverse suspension device (diameter: 9 mm; length; 35 mm) involves biodegradable poly-L-lactide/tri-calcium phosphate cross pin constructs whereby the tendon graft wraps 180°around it. Bilok ST is screwed across the tunnel which is different from other cross pin systems. A theoretical disadvantage of this implant is that a poor fit in the bone might result in a small amount of the graft slipping past the distal end of the screw.

Cross pin system

(Pinn-ACL)
The Pinn-ACL cross pin system (ConMed Linvatec Ltd) is a cancellous suspension device which was introduced in 2010 for graft fixation in anterior cruciate ligament. Theoretical advantages (rigid and strong reconstruction) of this implant are probably due to the different fixation principle used: fixation of the cross pin within the metaphysis results in a relatively short graft length.

Cross pin system (Rigidfix)The Cross pin system (Rigidfix) (DePuy Mitek Ltd) was introduced in 2003 for graft fixation in anterior cruciate ligament reconstruction. The implant consists of 2 bioabsorbable (poly-L-lactide) Rigidfix cross pins which are inserted across the graft through 2 parallel drill holes from the lateral femoral condyle perpendicular to the femoral socket made by a Rigidfix cross pin guide. Theoretical advantages of this implant are due to the expansion mechanism and include good structural properties, maintaining anterior knee stability, higher failure loads, the leeway for graft tunnel mismatch, lower synovitic reactions rate, relatively easy revision surgery and low complication rate. However, the resorbable pins are more expensive than resorbable screws. In addition, the pins penetrate the tendon graft in line with the collagen fibres, so slippage may occur as the collagen fibres separate under tensile stresses. The diameter of the pin is 3.3 mm for soft tissue and 2.7 mm for bone-patellar-tendon-bone. The length is 42 mm.

Cross pin system (Slingshot)The Slingshot systems and Transfix (see next) use the same method for tendon fixation and are very similar, the difference being that a hammer is used for Transfix screws and a screwdriver for slingshot screws.

Cross pin system (Transfix)The Cross pin system (Transfix) (Arthrex Ltd) was introduced in 1998 for graft fixation in anterior cruciate ligament reconstruction. The implant consists of a 50 mm metal or bioabsorbable pin which is inserted through the lateral femoral condyle and the graft passed around the implant with the help of the Transfix guide. The point of fixation is closer to the joint. Theoretical advantages of this implant are due to suspension mechanism and include fewer tunnel enlargements, high failure load, less loss of tension during repetitive loading cycles, fixation closer to the joint line, greater stiffness and pull-out strength and low complication rate. However, this implant is more expensive than the Endobutton. This implant has a range of different lengths from 40 mm to 55 mm.

Double Spike Plate (DSP)The Double Spike Plate (Meira Corp Nagoya Ltd) was developed in 2002 to regulate graft tension by separating the step of tension from that of graft fixation in anterior cruciate ligament reconstruction. The DSP consists of a 1.5 mm thick, 17 mm long and 11 mm wide plate made of titanium alloy with 3 holes and 27 mm long spikes on the reverse side. This implant may facilitate graft fixation under a predetermined amount of tension.

EndoPearlThe EndoPearl (Linvatec Ltd) which was introduced in 2001 is secured with 2 No. 5 Ethibond sutures that are countersunk in the indentations of the device; thus, there is no need for increasing tunnel diameter. The spherical EndoPearl device (diameters 7, 8, 9 mm) is chosen corresponding to the graft diameter.

EvolgateThe Evolgate (Citieffe Ltd) which was introduced in 2003 is a tibial fixation device for soft tissues that consists of 3 parts, all made of a titanium alloy: a screw, a coil that is inserted inside the bone tunnel to reinforce the walls of the tunnel, and a washer for cortical fixation.

Expansion boltThe expansion bolt (Resofix Ltd) (5.8/8.7 × 10 × 35 mm) was introduced in 1999 for graft fixation. It includes a semicircular upper shell, a planar lower shell, and an expansion wedge with an overall height of 5 mm. It is made out of poly-D,L-lactide (Resomer Ltd).

Interference screw (bioabsorbable)The bioabsorbable interference screw was introduced in 1995 for graft fixation in anterior cruciate ligament reconstruction. The materials of this bioabsorbable implant include polyglycolic acid, poly-L-lactic acid, poly-D, L-lactic acid, polyglycolic acid with trimethylene carbonate, poly-L-lactic acid with hydroxyapatite and poly-L-lactic acid with β-tricalcium phosphate. This implant was developed to overcome the shortcomings of the metallic interference screw. The theoretical disadvantages include increased risk of breakage, and risks of infection and foreign body reactions.

Interference screw (metallic)The metallic interference screw was introduced in 1983 for graft fixation in anterior cruciate ligament reconstruction. Advantages of metallic interference screws are high initial fixation strength and the ease of use. The theoretical disadvantages include the laceration of the sutures and grafts during insertion that may complicate the reconstructive surgery. In addition, metallic screws would hinder subsequent magnetic resonance imaging examination. Difficulties may also exist with the removal of the metallic implant in revision surgery.

IntrafixThe Intrafix system (DePuy Mitek Ltd) was introduced in 2003 for graft fixation in anterior cruciate ligament reconstruction. The implant is composed of an expansion sheath made of plastic or absorbable material and a tapered expansion polyethylene screw (diameter: 7 to 10 mm). Theoretical advantages of this implant are due to this combination device and include clearly superior strength in the fixation.

Ligament plateThe Ligament plate (Solco Ltd) was introduced in 2009 for graft fixation. It is made of a titanium-based alloy and has a U-shaped body for graft suspension and 2 wings that contain screw holes to allow secure femoral fixation with the screw.

Linx-HTThe Linx-HT (Mitek Ltd) was introduced in 2005. It suspends the graft from a screw that is fixed into the cancellous bone of the femoral metaphysis.

Metallic set screw systemThe Metallic set screw system (Arthrex Ltd) consists of a 9 × 30 mm metallic screw augmented with a 2.4 × 45 mm metallic pin that can be used for transverse femoral graft fixation.

StapleThe staples (Smith & Nephew Ltd) are often used as a supplementary device with an interference screw for tibial fixation.

Swing bridgeThe Swing bridge (Citieffe Ltd) was introduced in 2003 for graft fixation. It has an eyelet, through which the tendons are directly looped, and a smooth metal half ring for cortical suspension fixation on the femoral side when the device is inserted and impacted using an out-in technique.

WasherThere are 3 Washer devices for soft tissue grafts fixation in tibial side. One is the Washerlock (Arthrotek Ltd) which was introduced in 1999. It is 20 mm in diameter, has 4 11 mm long peripheral spikes that straddle the graft, and 19.6 mm-long centrally placed spikes that penetrate the graft in multiple locations. The others are Tandem Washers (2 soft tissue washers, Synthes Ltd) and a 20 mm spiked metal Washer (Linvatec Ltd). A 20 mm diameter metal Washer with 12 x 1.3 mm length spikes is used to compress the graft to the tibial cortex with a 4.5 mm diameter bicortical screw. Fixation with the Tandem Washers requires 2 4.5 mm diameter bicortical screws and 2 13.5 mm diameter plastic spiked washers spaced 15 mm apart in tandem.

 BTB = bone-patellar-tendon-bone
ST = soft tissue