Haglunds deformity- Endoscopic calcaneoplasty

Clinically, the achilles will have a classical cushion like swelling over the lower 2-3cm just above the heel insertion.
The swelling occurs in all layers including the pre-achilles bursa, the tendon and the retro-calcaneal bursa.
It can be quite warm to the touch and the pre-achilles bursa may make it superficially very tender too.

The lateral heel xray is a useful first investigation and may show a significant prominence of the posterior superior calcaneum, with the soft tissue shadow of the achilles having to bend around this.
In this case, there are also small spurs at the insertion. These are often present on lateral xrays and should be asymptomatic. If they are tender clinically, then treat as an insertional achilles tendonitis – an endoscopic calcaneoplasty is not indicated.
Higher than the insertion, the impinging prominence can be seen – in this cause it is quite rounded but may be sharp and even spur like.
As with all xrays, the rotation and alignment of the xray can be misleading and so may not show any prominence. For this reason multiplanar imaging is much more accurate – either CT or MRI.

MRI is the investigation of choice – it identifies the bony anatomy, the quality of the achilles tendon and any surrounding bursitis.
The T2 weighted (T2W) or proton (PD) sagittal images are best to show the pathology.

In this case, there is focal oedema within the achilles opposite the Haglunds bump (1.). The superior calcaneal prominence (Haglunds bump) is clearly visible (3.), with the achilles deviating around it. Note the large associated retrocalcaneal bursa (2.) between the two.
Also note that although there is oedema in the achilles, the fibrils are still normal and there is no expansion or swelling of the achilles. This indicates little or no disorganisation of the microstructure to suggest any tendinosis.
Also note that there are no signs of insertional pathology (4.) e.g. bone spurs or tendinosis / inflammation.

As with all surgery, positioning is important – it can either make things easy or really difficult.
The patient is in the lateral position, with the “bad side up” and the other leg in front. The feet need to be at the far end of the table, with the heel at the edge.
The leg is elevated on a bolster (a folded & taped pillow in this case), supporting the calf. This allows the heel to be free for xrays and also allows palpation of the medial side during surgery.

The theatre set up is crowded so its important to plan ahead. The camera stack, image intensifier and screen are both at the foot end, with yourself and the scrub nurse working in the area too.
The camera stack is placed on the other side of the table and the image intensifier comes in at the foot end at an angle, with the screen to one side.
The scrub nurse sets up at the foot end or to your side.

The portals are positioned to allow access to the superior surface of the calcaneum, in front of the achilles.As with all arthroscopies, correct placement of the portals is essential to allow full visualisation and access to the pathology.
Palpate the lateral border of the achilles as it comes up from the insertion (straight dotted line) and also the top of the calcaneum (curved dotted line).

The posterior portal is placed at the “axilla” where the achilles and calcaneum meet.
This is distal enough to avoid the main sural nerve, though there may be a posterior branch of the nerve here, so always use the “nick & spread technique” to avoid this. This is done by making a superficial incision just through the dermis and then using a small clip to dissect deeper to this – any nerves should now be out of the way.
The anterior portal is placed 2-3cm anteriorly, at the height of the top of the calcaneum, again using the “nick & spread technique” to avoid the sural nerve.

Use the image intensifier to get the position right – the portals need to be just at the top of the calcaneum.If they are too high, the access for the surgery is fine but the sural nerve will be at higher risk of injury.
If they are too low, it won’t be possible to do the surgery , though this is easily fixed by extending the portals proximally.

Two portals are made, one immediately anterior to the achilles and the other 2-3cm anterior to this, using X-ray guidanceThe portals need to be at least 2cm apart or the arthroscopy instruments will clash with each other. Conversely if too separately placed, access may be hard and the sural nerve is at risk.
The incisions are made vertically / longitudinally and approximately 7mm long. The sural nerve is at risk here and so a clip is used to “nick & spread” and avoid any damage.

With a clip, palpate the top of the bone through each portal to check that the portal heights and access are adequate. The clip should hit the bone and then be able to pass over the top without pulling on the skin / portals.
The burr can easily damage the skin – If the skin is pulling too tightly, release the skin to give better access.

Before any bone is resected, it’s important to lift the soft tissues off the top of the calcaneum first. This can be done with an elevator (or a clip in this case).
This provides a pocket clear of the soft tissues, to form a working area on top of the calcaneum. Without this, the burr is easily wrapped up in the soft tissues and trapped.
It also lifts the tissues off the bone and helps prevent small bone fragments being left attached to the soft tissues at the end.

Check the set-up of the minimally invasive equipment before starting.
This consists of a handpiece, powered by a central control unit and a foot pedal switch.
The handpiece has two connections – one for power and the other for a saline line to cool the burr. The saline line attaches to a small connector at the tip of the handpiece and continuously pumps a small jet of fluid to cool the burr.
The burr is inserts into the end of the handpiece and is locked in place by a collar – position C for “closed” & position O for “open”.
Note: The handpiece won’t work unless fully in the closed position.
The handpiece is operated by a foot-pedal and saline is pumped through automatically.
Note: Check the saline is flowing well before starting any resection.

Check the central control unit is on the correct settings.
These include speed, torque, saline delivery speed and direction. The latter is either forward or reverse, make sure its on forward or it won’t cut.
On the panel to the right of the display, there are controls for speed, torque and programme. There is no need to change the programme setting. There is also a gearing number which doesn’t need changing from its default setting of 20:1.
My standard setting is 300 revs, torque is increased to 80, 2 bars of saline delivery and the burr set on forward direction.

Control of the handpiece is done via a foot pedal.
The main switch(1.) controls on & off.
The three buttons on the top don’t really need changing.
The left button (2.) controls the flow of saline.
The middle button (3.) is forward / reverse – it’s easy to press this accidentally so if the burr isn’t cutting, check the controller isn’t in reverse!
The right button (4.) changes the programme setting – its not necessary to change this.

The pumped saline is delivered by a bag and tubing that runs through a clamp on the side of the control unit.
Ensure that special region of tubing is inserted all the way in the clamp or it won’t pump saline – this is easily done. It takes a few seconds for the water to reach the handpiece – check its flowing well before starting any resection or you will burn the skin.

Using a minimally invasive 4.1 mm burr is quite different to normal surgery in that it is “blind” surgery and it is done by feel.
It will take a while to get used to how quickly or slowly the bone is resected, how it feels when the burr is cutting or how it feels when it is clogged.
It’s important to use the image intensifier to guide you though initially it will feel slow and awkward. With experience it will be come quicker and a very useful technique.

Commence bone resection with a minimally invasive burr.
The burr is tapered with specially designed flutes that cut bone in preference to the soft tissues – although the soft tissues can still be damaged so remain careful.
Although the burr rotates quite slowly compared to other burrs you may be familiar with e.g. pen drives, it still gets very hot and the skin is easily burnt. Because of this it has a saline cooling system.

Insert the burr through the anterior portal and only once the cutting flutes are deep to the skin edges, start the burr runningWork from near to far, in a sweeping action over the top of the bone. Feel your way, over the bone with using the burr and resecting the bone nearest the portal. Initially very little bone is resected as the soft-tissue / periosteum comes of first.
Ideally take away an arc of 1-2mm off each time, so that a smooth level surface is shaved off each time. It’s not possible to cover the entire resection area in one sweep, so several arcs will need to be made.

Once resection has started periodically switch to use the elevator to feel the bony surfaces from medial to lateral and from anterior to posterior to gauge how the resection is progressing.A lot of this operation is done by haptic feedback and “by feel”, in conjunction with the image intensifier.
It’s important to build up a “mental map” of the bony resection and the terrain.
For the first few operations, its worthwhile using the image intensifier frequently, to help map out the area.

Using the image intensifier regularly helps guide the resection.
With the leg supported by the bolster, it can be easily moved back off the edge of the table and placed over the image receiver.
In this case I am using the mini-C arm image intensifier – its very portable and quicker to use. The standard C-arm is fine but I find it more cumbersome.
The imaging tends to give a good lateral view if the receiver is at the same height as the heel – if not change the orientation of the heel to get a better lateral image.

I prefer to hold the burr like a pencil, with my hand held firmly against the heel.
By doing this, it gives me a centre-point so that I can mentally reference the angle and height of the resection.
With my hand fixed, the centre / fulcrum of my arc is at the portal, which prevents the skin from being pulled and damaged by the burr.

As the bone is covered with periosteum and fibrocartilage, the initial resection is slow because the burr clogs easily. It will need removing and cleaning with a wet swab every few seconds, at the start.
The burr sounds quiet when its on soft tissue. When it hits clean bone and starts cutting, you will hear it change note to more of a buzzing sound and the handpiece has a gritty feedback.

To avoid the burr resecting one area too deeply keep sweeping over the bone, to and fro, and resect it progressively in even layers.Using a sweeping action gives regular feedback of the anatomy and terrain and avoids causing any low or high spots.

Once the dorsal lateral aspect has been flattened, continue carefully using palpation medially, to ensure complete resection all the way across. On the far medial side, it’s essential to palpate the medial heel at the same time. This will guide the depth of resection – you can feel the tip of the burr and so avoid damaging any of the medial tissues.
Having the foot lifted by the bolster makes this easier.
Note: The medial neurovascular bundle will be 3-4cm anteriorly and out of harm’s way.

It’s actually quite hard to take too much bone away and the tendency is nearly always to take too little.
Check the resection height regularly, with the Image Intensifier.
Note: There is much less bone resection using this technique, than with an open osteotomy.

Finally turn to the lateral aspect of the superior calcaneus with the burr, being guided by the intensifier and careful probing with the burr not rotatingThe hardest area to resect is the lateral bone near the portals – this is easily left too high and gives a misleading appearance on the xray.
The temptation is to keep resecting more bone from the easy to get to places, when in fact it’s only a high area on the lateral edge, close to the portals.
Use the image intensifier and the burr together to “feel” where the high spots are.

Continue the burr resection until you have obviously resected below the upper border of the body of the calcaneum.The main resection has now been achieved and the impinging bone is gone – the debris will all be removed during the endoscopy.
There is often still an impression of a prominence posteriorly – this area is very close to the achilles and I prefer to view this directly with the scope before resecting any more.

Endoscopy follows the bone burring and is performed using the standard ankle scope (4.5mm) and soft tissue shaver.To start, I prefer to place the shaver in the posterior portal nearest the achilles, with the camera in the anterior portal, but it can easily be the other way round.
The shaver is placed with the blade facing away from the achilles toward the scope.

The initial endoscopy view will be obscured by soft tissue and a working area needs to be made with the shaver.Normally, in arthroscopy, we are used to entering a joint via the capsule and inflating the joint with saline. This provides a natural viewing and working area.
There is no natural cavity here and a working area needs to fashioned, free from soft tissues, so that the achilles tendon and the calcaneal surfaces can be seen.
This is done by feel and vision – feel the shaver and camera hitting and ‘walk’ the shaver along the camera until the shaver can be seen amongst the tissues – Here just visible as a grey blur at the bottom (1.)
Once the shaver comes into view – start shaving the soft-tissues.

Surprisingly little shaving is needed to open up the working area and a clear view rapidly forms.
This image is very early on after minimal shaving. The achilles is off screen to the left (1.) and the anterior structures behind the ankle on the right (2.).
Here, a large area of synovitis / bursitis is seen just to the right of the shaver, on the anterior margin of the working area.

Clear the soft tissues arthroscopically from the superior calcaneum to expose the achilles insertion.As with all arthroscopy, you will need to change the camera / shaver to the other portals to get a complete view of the surgical area. This is especially true of the tissues close to the portals.
Its sensible to go slowly and carefully with the resection until the anatomy becomes familiar.
In this case, the camera is in the achilles portal, to view the anterior border of the surgical area and the shaver is in the anterior portal, resecting any inflamed tissue there.

Once a working space is created shave from superior to inferior to expose the top of the calcaneum and then use this as a reference point to clear tissue from.Here the shaver is on top of the exposed trabecular bone of the calcaneum (1.). The Achilles tendon is off-screen to the left of the image (2.). To the right of the screen are the anterior tissues, at the back of the ankle.

Once a clear area is formed, shave towards the achilles insertion, staying just above the bone resection and removing the soft tissues and any bone debris.Work towards the achilles, clearing tissue and bone debris away from the top of the calcaneum and the pre-achilles region.
Here the shaver is on the calcaneum with the medial edge of the achilles just beyond the shaver (1.).
A deep surface tear is just above the shaver with the fibres of the tendon lying horizontally (2.).

Inspect the achilles insertion and use the shaver to resect any smaller areas of impinging bone, down to the junction with the tendon fibres.In this image, there is a small ridge on the calcaneum, that has been left by the MI burr (1.). This may still cause impingement – this is easily shaved away with the soft-tissue shaver. The bone is cancellous and soft – the soft-tissue shaver is suitable and there is no need for a bony resector.
Often the achilles will have some degenerate fibres and synovitis on the deep surface – remove these with the shaver.

Once the Achilles inserted is cleared arthroscopically rotate the camera (1.) to view the whole working area, especially superiorly and the area close to the portals where things are easily missed.Inspect the whole retrocalcaneal region and remove any synovitis seen – often there is some superiorly under Karger’s fat pad that needs removal.

The cleaned and debrided achilles tendon (1.), with no impingement. Resected calcaneal process & insertion (2.)
The final appearance should look like this, with no sign of bursitis and no impinging bone or loose fibres.

The impinging bone has been resected including the retrocalcaneal surface (1.). The Achilles insertion is clearly seen (2.) and no synovitis remains.
Of course, it’s perfectly possible to perform the bony resection using only endoscopy and a bone resector. Personally, I find this much harder to do. Harder to orientate my instruments and to perform a good resection of the prominent bone.

Once the retrocalcaneal region has been cleared, check the resection finally with xray. It’s important to remove all loose bony fragments.
The final image should look similar to the left hand image – compare with the pre-op right side image before resection.

The wounds are closed with interrupted sutures and covered with an absorbent dressing, wool and a crepe bandage. There is no need for a plastercast and long leg walker boot is fitted on the ward. Keep the bandages to a minimum , or the boot won’t fit over them.