ACL reconstruction with 6 strand hamstring allograft and Smith and Nephew Endobutton and RCI screw

Imaging – coronal MRI showing a bare lateral wall (1) indicating an ACL rupture from the lateral femoral condyle

Imaging – Axial MRI
Rupture ACL – (1)

Imaging – Sagittal MRI – notice the low lying ACL (1)

Preparation and selection of kit is important – I use a Linvatec hamstring stripper, Mitek reamers, Endobutton and Metal interference screw (Quick Start or RCI) for most ACL reconstructions
The Quick Start is from Innovate Orthopaedics. This has a novel double thread to optimise early and easy engagement.
The RCI is the original expanded head interference screw from Smith and Nephew. I still like the metal (Titanium) version as this allows easy visualisation on XR and easy removal should this be necessary at whatever timepoint in the future.

Operative set up is important – having the screen directly above the patient minimises the surgeon’s twisting which has ergonomic advantages
This image was taken during this ACL reconstruction case, but as can be seen on the screen, this particular element of the procedure is a meniscal repair.

The operative leg is supported with a side support and a foot holder, with the knee flexed to 90 degrees.I like to wrap the opposite leg which helps heat retention and prevents the leg dislodging off the table. It also stops adhesive drapes sticking to the Bair Hugger (which is carefully stuck to the patients’ skin to avoid air leak into the laminar flow operative zone)

Preparation with 2% chlorhexidine in alcohol and my standard arthroscopic draping including the foot in the preparation and then covering with a large sterile glove. The arthroscopic collection pouch can be part of your drape or alternatively these can be free-standing items which go over the drape.

Examination, formation of arthroscopic portals and diagnostic sweep is the first main event during an ACL reconstruction I like to harvest hamstrings through a nearly vertical incision – slightly oblique in the line of the saphenous nerve branches to try and minimise neuroma and numbness laterally.
For the portals I prefer nearly vertical for the high portals (anterolateral and anteromedial) and nearly horizontal for the low accessory medial portal.
Pure vertical or horizontal incisions are only extendable in one plane and by being oblique this gives the surgeon some flexibility or portal adjustment. In addition the cutaneous nerve branches run obliquely around the knee and parenthesis and neuroma formation are not unknown following arthroscopic surgery.
A pure horizontal low AM portal would minimise the risk to the medial meniscus but an oblique at 45 degrees is best for minimising cutaneous nerve damage to infra-patella branches of the saphenous nerve. Hence my compromise of near horizontal for the low accessory medial portal.

Pre-infiltration with adrenalinised local anaesthetic helps for reducing bleeding and improved analgesia helps the patient.
I use a multi-modal ‘cocktail’ of:
150ml of 0.1% Marcain with 0.6mg Adrenaline in 3x50ml syringes.
In one of the syringes we add:
30mg Ketorolac
10mg Morphine
The superficial infiltration performed prior to incision is Marcain and Adrenaline only.
I infiltrate around the knee – not into the knee cavity. Approximately 20ml to the medial side and 20 ml to the lateral side and 10ml around the Hamstring harvest site initially

The ACL injury is confirmed (1) and an accessory medial portal positioned by inserting a long needle (Venflon – labelled 4) along the track of the future drill for the femoral tunnel
Once the trajectory of the Venflon/needle is confirmed (from arthroscopic visualisation) not to conflict with the medial femoral condyle, but allowing the tip of the needle to touch the ACL footprint (site of future drilling) then the accessory medial portal can be made where the venflon/needle enters the skin.
I prefer a nearly horizontal incision for the accessory medial portal as described above.
I use an antegrade drilling technique from outside in, viewing from a high and very anterior anteromedial portal and drilling from a low and more medial accessory medial portal.
The importance of this step is to check the trajectory of the Venflon from the skin, past the medial condyle(2), allowing enough room for a reamer to pass without causing chondral damage, then up to the lateral wall close to the bifurcate ridge at the centre of the ACL origin (3).

Once the diagnostic sweep has been performed any meniscal or chondral injuries should be addressed. In this case a medial meniscal repair was needed.
This is covered in the following OrthOracle techniques.
Meniscal repair using Smith and Nephew fast-fix 360 system and knee arthroscopy
Arthroscopic lateral meniscal repair with fibrin clot and bone marrow aspirate using Smith and Nephew Fast Fix 360 system.

Some of the ACL stump is removed arthroscopically and the lateral femoral wall is partially cleared using a radiofrequency device . I use the Flo 50 from Smith Nephew as this has 3 settings for different applications
For the lateral wall clearance, I tend to remove very little tissue now, but during initial stages of learning this operation a clearer vision of the lateral wall will be required and training surgeons should be prepared to remove as much as necessary to achieve a good view.
I still ensure that the back of the notch is always seen.

I find the high power setting works very well and with this device if there is any bleeding, the coagulation function stops it efficiently. This is important as I do not use a tourniquet – all of these images are tourniquet free
This image is taken with the Flo 50 on high power setting, removing some of the ACL stump (1). Notice the bubbles (2)which need to be irrigated away to maintain vision using the hand pump or automatic irrigation pump.

After clearing of the lateral wall, image taken with the Flo 50 ‘turned off’.

The malleable intra-articular ruler (Smith Nephew) is fashioned by hand into a gentle curve to allow introduction from the antero-lateral portal and then aimed around the lateral femoral condyle to measure the depth of the lateral notch.
The obturator is aiming at the ‘half-way’ point (12) which is simply the depth of the notch on the lateral wall divided by two. This corresponds to the centre of the ACL.
This will be used in the next slides to position the Awl to define the start of the femoral tunnel.

With the scope (1) in the antero-medial portal, the awl (2) from the accessory medial mark the start of the femoral tunnel in the lateral condyleThe awl (‘chondral pick’ or ‘Steadman awl’) is used to do this.
The ruler is in my hand-3.

The depth of the lateral femoral wall is measured with the ruler
In this case 22mm from posterior cartilage to anterior cartilage.
The awl is inside the knee and ready to mark the start of the femoral tunnel at the ‘half way point’ (24mm/2 = 12mm)

The femoral starting hole for the drill has been formed by the awl (1)
This entry whole in the lateral femoral wall is at 12mm (1) This image has been taken directly from the screen intraoperatively and corresponds to the intra-articular photograph taken from the scope in the next slide…

Arthroscopic image close-up of the lateral wall with the femoral starter hole (1) and the malleable ruler still in place
Notice the Bifurcate Ridge (2) of the Lateral Femoral Condyle which divides the two main bundles of the ACL – the posterolateral (PL) and anteromedial (AM) bundles
The AM bundle is deep to the ridge and higher in the notch, whereas the PL bundle is shallower and lower.
I have positioned this starter whole just deep to the bifurcate ridge and biassed towards an AM position from the centre of the ACL femoral footprint.

The femoral tunnel is drilled to a diameter of 4.5mm across the lateral condyle from the pilot hole in the notch.The scope still in the anteromedial portal is then positioned to look down (light lead pointing up – 1) and the drill (2) is introduced into the knee from the accessory medial portal
This drill is a solid 4.5mm pointed-tip drill. The point fits into the pilot hole made by the awl previously.
The drill needs to be held firm and the scope maintaining vision of the drill in the pilot hole as the knee is then flexed by the assistant into the highest flexion possible in the next slide.
For a left ACLR, I would normally hold the drill in my left hand and the scope in my right hand (with ring finger touching the scope-portal aperture for best control) but we have moved our hands away for this photograph.

The knee is hyperflexed to allow accessory medial portal drilling of the femoral tunnel from the notch through the far lateral cortex.
The advice to the assistant is to slowly draw the foot as close to the patient’s thigh as possible – for this left ACLR, by using the assistant’s left hand. It is often advisable to apply pressure on the patient’s thigh (with the assistant’s opposite hand -right hand here) to allow the hyper flexed position we need for drilling of the femoral tunnel.
There are alternative strategies such as flexible reamers or retrograde drilling if you find this step hard.
It is important to visualise the medial femoral condyle with the arthroscope before drilling to prevent chondral damage form the drill.

Intra-articular view of the 4.5mm drill (1) in the pilot hole and about to drill the femoral tunnel in the lateral femoral condyle (2)

The length of the femoral tunnel is measured with the Endobutton Depth Gauge, 1.This obviously depends on the size of the patient, but a range of 30-45mm is a useful guide.

The femoral tunnel is measured at 42mm – where the ruler disppears into the lateral femoral condyle (42) on the image.
Each laser-marked division is 2mm.

Harvest the hamstring graft, either just Semi-Tendonosis (ST) or both ST and Gracilis. The incision is centred over the insertion of the medial hamstrings, anterior to the superficial MCL.Whilst there is a size difference between patients a rough guide is useful to learn in terms of your own fingers! I use a distance of 3 fingers down from the tibia-femoral joint line and 2 fingers medial to the lateral border of the tibial tubercle. This forms the starting point for palpation of the hamstring insertion which feels like a hollow then a bump moving from proximal to distal.
I prefer a slightly oblique incision as explained earlier to reduce the chance of nerve damage and for good cosmesis.
The decision on harvesting ST alone or Gracilis too, depends on the size and length of the ST harvested and the size of the patient. As a guide, aim for a total graft construct of 100mm including the suspensory fixation (15-20mm Endobutton usually for me). Thus if ST can be folded over 4 times and achieve 80mm, there is sufficient length.
If this is not possible then 3 strands of ST with the addition of Gracilis (2 0r 3 strands) would make a 5 or 6 strand graft which will be in the region of 80-90mm long and 8-9.5mm in diameter. With the addition of a button/loop the total length is then 100-110mm.

A swab is used to cover the arthroscopic portals and another swab introduced via a Lehey clamp is used to sweep away the fat from the underlying sartorius fascia

The fascia is then divided transversely immediately proximal to the palpable ‘pes asnerinus’ (or goose’s foot) which represents the insertion of the sartorius, gracilis and semi-tendonosus tendons.

By using a curved haemostat (the Lehey is perfect for this task) the medial hamstring insertion is delivered from the undersurface of the Sartorius fascia and into the incision.

Placing a swab between the tendon and the surgeon’s finger is a useful step to improve the comfort of the next step for the surgeon!

I like to place my finger under the tendon during harvest with a stripper – this allows me to check on the tension being applied to the insertion of the hamstrings by the stripper.
If the force is too large, then the hamstring insertion can be avulsed and the tendon will retract proximally.

Using curved dissecting scissors the vinculae (which supply the tendons) are divided close to the tendon with the curve of the scissors away from the tendon
There is a risk of damaging the tendon during this step, but without this removal of vinculae there is an even greater chance of tendon damage and transection during the stripping stage below.

By pulling the tendon and palpating the skin of the distal thigh medially (1) it is possible to detect any retained vinculae before stripping.

Carefully insert the tendons (within the incision) into the mouth(2) of the Linvatec hamstring stripper (1)with the guard closed.The guard of the Linvatec stripper is closed by rotating the lever on the handle to ‘closed’ which is the middle position – see next slide marked ‘1’.

Steady pressure is applied to the Hamstring stripper with one hand (right) whilst the other hand (left) is holding the tendon at its insertion and protected by a swab.
The stripper usually inserts up to the handle and then the tendon separates from the muscle body without the need for a formal ‘cut’ which is achieved by rotating the trigger on the stripper.
The stripper usually inserts to the handle and then the tendon separates from the muscle body without the need for a formal ‘cut’ which is achieved by rotating the trigger on the stripper from ‘closed’ (1) to ‘cut’ (2).

Using the hamstring stripper as a target for local anaesthetic infiltration (LAI) ensures that the local anaesthetic is at the site of hamstring tendon removal

The Semi-tendinosus tendon (1) is then first withdrawn from its proximal end as the stripper is removed out of the woundFurther anaesthetic is placed around the anterior soft tissues.

The Hamstring stripper step is then repeated to harvest the gracilis tendonNotice how I am holding the ST tendon in my left hand as well as tensioning the gracilis as the stripper is introduced.

By using one blade of a pair of a pair of scissors, all attached muscle is stripped off the tendons once harvested.Similarly vinculae are removed to leave smooth, long tendons.
Notice the position of the tendon graft (1) held between my thumb (2) and one blade of a pair of scissors (3)

A six strand graft is then made by suturing the end of the two tendons to an Endobutton (1) and then looping the two tendons around a nylon tape (2) and then passing back through the endobutton, before clamping the two free ends back to the nylon tape with a haemostat (3)The decision on harvesting ST alone or Gracilis too, depends on the size and length of the ST harvested and the size of the patient. As a guide aim for a total graft construct of 100mm including the suspensory fixation (15-20mm Endobutton usually for me).
Three strands of ST with the addition of 3 strands of Gracilis (2 0r 3 strands) has made a 6 strand graft which will be in the region of 80-90mm long and 8-9.5mm in diameter. With the addition of a button/loop (1) the total length is then 100-110mm. The Nylon tape (2) provides the necessary traction for the graft outside the tunnel to allow fixation under tension without unnecessary removal of any tendon.
The Haemostat (curved artery clip – 3) is securing the free tendon ends and the Nylon tape together, but it is not catching the looped tendon

I use an ultra-strong braided suture to construct the graft. Notice that after initially suturing the graft to the button I leave the end long (1) and the FiberWire suture still attached (2)
I am using number 2 FiberWire (Arthrex) here. Alternative sutures would be Number 2 Ultrabraid or Orthocord. In other words a high tensile non-absorbable suture.

The graft is secured onto the button first, looping the suture around the button and for 2-3 throws through the graft, then back through the button and finally tied off and cut.

Then the trailing (adjacent the nylon loop) end of the graft is sutured, but avoiding going through the nylon tape – this allows the tape to be pulled out at the end after fixation.

Once sutured with endobuttons sizing of the Graft is performed by matching the graft diameter to known sized tubes.Here there is an 8.5mm and 9mm tube placed over an arthroscopic grabber – and the leading sutures of the endobutton are placed into the clasps of the grabber to allow passage of the graft through the tubes.
This stage may need to be repeated, but with practice the surgical hand becomes an excellent guide of girth!

This is the Mitek sizing device which is useful for larger grafts
It also has slits in the side of the cylinders to allow the graft pull-through sutures to be slotted in front the side, removing the need for exchange with an arthroscopic grabber as above.
The down-side of the slotted graft-measurer is that the graft can expand into the slot…so the graft may be a little larger than the diameter of the tube, thus compromising the accuracy of the sizing
Consequently be careful if the graft feels tight in the chosen size slot……the graft is actually bigger!

It is worth keeping a sizing tube over the tightest part of the graft – usually the button/graft junction or the tail end. I often use 2 tubes to cover the whole graft – and then place it in a graft bath of saline and 1g of Vancomycin. These are sizing tubes from an RCI reaming set, but many others are available such as the Arthrex Graft compression tubes.
Notice the swab in the ‘Vanc-bath’ which will be wrapped around the graft in the next image.

The graft is then wrapped up in the vancomycin-soaked swab and the sutures gently wound around the swab…..

For safe keeping, I place the wrapped Graft into a surgical glove

The glove is tied closed and placed in a receiver – this removes a risk of graft contamination, particularly the potential disaster of a graft being dropped on the floor during the next steps of the operation.

The femoral tunnel is then reamed over a Beath pin to the corresponding size to the femoral diameter of the graft, to create a femoral socket.The minimum length of this socket depends on the relative length of the femoral tunnel and the loop length of the suspensory fixation.
However the simplest solution is to ream up to the cortex, but not through the lateral femoral cortex.
If that happens then either a lateral wall alternative fixation (post screw and tie down of suture ends from the button or a Swivel-lok from Arthrex) or a femoral interference screw (to create aperture fixation) should be used.

The knee must be at the same position of flexion (hyerflexion) as when the femoral tunnel was drilled, so that the reamer (1) does not eccentrically remove bone.
Notice how the assistant’s arms are away from the knee and thus outside the scope of this image.
The assistant is holding the ankle with left hand and patient’s thigh with their right hand. The assistant’s right hand should push down on the thigh (2) to hold the knee locked in this position during reaming.

The bone swarf from reaming is then removed .
I use a sucker tip (2) to collect the bone swarf. Simply introduce the sucker tip into the accessory medial portal and obstruct the draining end (and close the suction control hole where applicable). Raise the intra-articular pressure by a couple of hand pumps or allow the pressure to raise with the arthroscopic pump, then release the sucker to drain freely.
It is worth tapping the popliteal fossa (1) as there is often a collection of bone swarf which falls posteriorly.

A nylon pull through loop is passed from the accessory medial portal through the femoral tunnel.This can be looped on itself and secured outside the knee or alternatively the loop simply withdrawn from the lateral side so that the loop (1) is just inside the femoral tunnel (2) and away from potential snagging by the tibial reamer.

The ‘Gold Guide’ – or Smith and Nephew tibial elbow aimer (1) is then prepared to identify and drill the tibial tunnel.
As the surgeon you will be asked what angle you want this setting to? A sensible answer is between the 50 and 55mm markings (52.5 degrees!).
In reality I virtually always change this angle during introduction of the device (using the silver tightening wheel 3) as this allows independent aperture identification intra-articularly and then the guide sleeve (2) is positioned within the hamstring harvest wound on the bare area of the tibia.

The Smith and Nephew tibial elbow aimer is set between 50-55 usually, inserted into the anteromedial portal in preparation for tibial tunnel drilling. Introduction of the Gold Guide (1) is best done upside down, using the anteromedial portal, then rotate this round into the correct position.
Once the tip or elbow aimer are introduced into the knee the guide (1) is rotated 180 degrees so that the tibial aiming guide (2) is sitting within the hamstring harvest incision (3)

The elbow aimer is positioned relative to the ACL remnant, the medial tibial spine (palpated arthroscopically), the PCL and the anterior horn of the lateral meniscus (both visualised)

Tibial tunnel preparation – deciding where to drill1 = PCL
2 = Lateral Wall
3 = Gold Guide Elbow Aimer.

The Beath (passing) pin is inserted through the tibial guide, aiming for the centre of the ACL stump and the lateral meniscal anterior root.The guide is then removed leaving the pin in place in the tibia.

The passing pin (1) is inserted in the centre of the ACL stump (2).
Another useful landmark (although not in this image) is the lateral meniscal anterior root.

The tibial passing pin is reamed with a small diameter reamer – eg 5mm

Reversing the Beath pin prior to removal of the first reamer will allow fine tuning of the final tibial tunnel placementTo achieve this fine-tuning, the flat eyelet of the passing pin is held intra-articualrly by a clamp (I use a Lehey from a medial portal). The most proximal end of the tibial tunnel can then be biassed by moving the pin within the 5mm tunnel. For example the tunnel could be pushed more medial and posterior by manipulating the Lehey clamp which in turn is holding the Beath pin. The correct size reamer to match the graft is then taken and the tunnel will be moved towards the posterior and medial sides of the original tunnel.

The Beath pin is held with a Lehey clamp inside the knee and the ideal tibial tunnel position chosen within the 5mm diameter already reamed.

The tibial tunnel is expanded with reamer size corresponding to the graft diameter

Clearance of soft tissue around the tibial tunnel entrance – using a large arthroscopic punch is ideal.

This small amount of soft tissue (removed by the arthroscopic punch -1) comes from around the entrance of the tibial tunnel anteriorly.
Notice my finger (2) for appreciation of the scale.
If this is not removed it can block graft passage later on.

The nylon loop is retrieved from the femoral tunnel and pulled down the tibial tunnelThe loop is retrieved from the femoral tunnel (by an arthroscopic hook or a meniscal grabber) into the knee and then retrieved from the anterior side of the tibial tunnel by the same instrument placed up the tibial tunnel into the knee.

The 6 strand graft is removed from the Vanc bath and glove and covered with Instillagel
Instillagel is a proprietary brand of sterile lubricating jelly with Lidocaine, commonly used for urinary catheter insertion.

More Instillagel is applied into the tibial tunnel.

The hamstring graft is introduced through the Nylon loop and then shuttled across both tibial and femoral tunnels….

The graft is pulled across using the white ultrabraid (1) which is preloaded on the Endobutton.

If more traction is needed to pull the graft through, then a Kocher clamp (1) may be clipped onto the Ultrabraid (away from the skin) and then the ultrabraid wound around the clamp to achieve a short lever which can then be traction from the lateral side.
Please note this image is used to show cutting one green and one white suture (2) before pulling the other two out, but the Kocher clamp used to pull the graft up the the tunnels is still attached and hence using the image now.

Once the Graft is fully inserted into the femoral tunnel, the green (Ethibond) sutures can then be pulled to toggle the endobutton from parallel to the femoral tunnel to perpendicular, and then the graft tensioned, pulling from the tibial side.It is sensible to cycle the knee from 0-70 degrees (approximately 10-20 times) to ensure that the endobutton is sat down on the lateral femoral cortex and the graft is appropriately tensioned before moving onto fixation of the tibial side….

Two of the pull through sutures (one white, one green) are cut flush to the skin and then the other two sutures removed
The graft can then be pulled back down the tibia and the knee cycled to ensure that the graft is tensioned and the endobutton is sitting on the lateral femoral cortex.

A tibial guide wire for the chosen interference screw is inserted in the tibial tunnel on the lateral side of the graft.
This forces the graft medially to give more obliquity and therefore better rotational control.

Tibial fixation is then completed by insertion of the RCI screw along the guide wire.A metal RCI screw (1) is inserted over the guide wire with traction on the graft using the Nylon tape (2).
I place the knee in approximately 70 degrees – with the foot on the foot roll to start the interference screw, but then straighten the knee and apply a reverse Lachman as in the next image

Reverse Lachman test is used to tension the graft as the tibial interference screw is tightened home.The assistants’ hands (1&2) perform a reverse Lachman. Hand 1pushes anteriorly and hand 2 pushes posteriorly.
The surgeons’ hands (3&4) tension the graft and insert the interference screw. For this left knee I am pulling the graft (Nylon tape) with my left hand (3) and inserting a metal RCI screw with my right hand (4).

Examination of the knee to ensure that stability is restored after fixation of the graft.I use a Pivot Shift, Anterior Drawer and Lachman test at this stage.
The key for me is abolition of the pivot and full range of the knee.

Deep dermal closure with absorbable suture – I use 2-0 vicryl

Good skin closure is essential to prevent wound complications.
Subcuticular (absorbable monofilament such as 3-0 Monocryl) and steristrips are applied

Occlusive dressings are applied with the knee in flexion to help with early mobility and allow early showering.

Crepe (criss-crossed) on top of a thinly applied wool bandage from ankle to thigh.

Post-operative XR – AP
The endobutton is sitting down on the lateral femoral cortex
The tibial interference screw is not prominent in the joint.

Post-operative XR – Lateral
The tibial RCI screw is sitting within the tibia, not prominent anteriorly or intra-articularly.
The graft is sitting posterior and medial to the screw.