Chronic Osteomyelitis post knee fusion and revision fusion following multi ligamentous knee injury and repair
Chronic Osteomyelitis still represents difficult problem in a day-to-day practice of an orthopaedic surgeon. Closer to the centre of body we come, more difficult it gets to eradicate the infection in a bone.
It is well accepted that the most reliable way of eradicating a bone infection is to remove the infected bone. Unfortunately this is not always possible. Even if it is, it comes with a price and limitations.
Growing new bone does not represent a significant challenge any more in current orthopaedic practice. In Chronic Osteomyelitis management, growing new bone using callus distraction methods remains reliable and predictable tasks. Soft tissue management unfortunately is not.
At this stage we became involved. Thorough discussion about different treatment options was carried out and finally agreed to proceed with limb salvage using limb reconstruction techniques. The plan was divided into stages:
1. Resection of the infected bone with insertion of a cement spacer and temporary stabilisation of the leg if possible internal fixation but not a nail
After 4-6 weeks we planned to proceed to:
2. Application of external fixator and filling the bone defect using callus distraction techniques providing that soft tissue recovered and infection settled
It was completed relatively uneventful. Infection settled. Sinuses dried up. Decision was made to continue with Stage 2.
Initial plan was to perform corticotomies in the proximal femur and the distal tibia. This was abandoned due to an unpredictable nature of the problem. Only distal tibia corticotomy was planned to allow exit option in case of failure in the form of an above knee amputation.
From the previous case we have learned that "double pulley" system is just about "strong" enough. Hence "tripple pulley" system was created.
27 February 2017
Calus distraction started really well. Good regenerate. No clinical sign of infection. Also seroma is currently under control.
Two half pins were removed and callus distraction will continue using cable - 3 clicks 4 times per day (triple pulley).
10 March 2017
Excellent progress. Infection so far under control. Patient very happy and progressing well. as you can see on the X/rays below there is an excellent regenerate. So far we have grown 3.5cm of bone. 18.5cm to go. Pulleys are working brilliantly so far.
27 March 2017
Patient was admitted with signs of infection, possible sepsis. Swelling formed at the from of the leg, at the level of the previous knee joint. Unfortunately it bursted before we took him to theatre where we debrided it, washed it out thoroughly and inserted an Irrigation VAC. Samples were taken as well and antibiotics were adjusted as per Infectious Diseases Consultant advice.
On the X-ray I can see very good regenerate for now. It was not obvious during the surgery that the infection has propagated down the leg, but clinically it certainly did not look like it.
19 April 2017
Irrigation VAC has been changed three times. It looks that the infection is under control. The cavity is shrinking in volume.
Regenerate continues to grow despite everything.
22 April 2017
Irrigation VAC has been removed. Wound clean. Leg shortened at the level of the defect to allow tension free wound closure over a Redivac drain. Proximal edge of the transported fragment was chamfered to allow easier future passage underneath the scar. For now will use clickers again to distract the corticotomy and transport the fragment, when cable and pulleys will maintain fragment's proximal position until it gets safe to dock the fragment.
09 May 2017
Infection is again under control. Patient feels really good. The skin and the wound healed and healthy looking. The same with all pin sites. So far we have reached 9.5cm of regenerate and it looks good as you can see on the X-rays below. There are calcifications at the knee level but also still some remnants from Stimulan. No fluid level at the level of previous abscess treated with Irrigation VAC what is encouraging.
13 June 2017
It is going surprisingly well. Soft tissues in great condition. No sign of infection. Patient well in himself.
Leg length restored. X-ray below shows 13-14 cm of a good quality regenerate.
Will restart pulling using cable as it looks that the skin will slide away from the bone.
Main problem is stiffness of the ankle joint. It looks that we will have to use a foot plate to overcome the stiffness.
27 June 2017
No sign of infection. Excellent progress of regenerate. Already at 14 cm. No major pin site issues. Ankle progressively stiffer.
11 July 2017
Further progress in the regenerate. Almost 16 cm. And 10 cm more to go. Skin crease at the defect level is still a bit of a problem. Pin sites on the distal tibia are getting more painful, probably due to the increased tension. One of the medial pin sites on the thigh is inflamed as well. Will clean and dress them and if necessary add some more wires or half pins.
Ankle stiffness with equinus and varus continues to be a problem. In fact it is getting worse and is out of control.
01 August 2017
All going quite well. Wound has healed. Ankle contracture is slowly improving. Some discharge around the most distal pins.
12 September 2017
Patient is feeling well in himself. Pin sites are under control. So far we have grown around 22cm of a new bone. Unfortunately the fold of the skin is on the way again and will have to be released from the docking site. The leg is still a bit shorter hence we will continue with lengthening the leg using clickers.
Foot plate is still in place and ankle ROM is improving the same can be said for varus of the foot.
18 September 2017
Skin release showed more important underlaying problem. The crust which seemed superficial was actually sitting on the bone. When crust removed, we were left with a defect in the skin. After debridement of the bone (bone edges were bleeding nicely), the pulley system was removed and replace with standard olive wires. To allow soft tissue cover we acutely shortened the leg.
For future lengthening will use clickers only. Further docking will be completed by TSF struts. The defect was filled with Stimulan beads with antibiotics.
26 September 2017
Wounds are healing nicely. Some pin sites discharge but nothing major.
Right leg is still around 7-8 cm shorter as per long leg alignment films. Regenerate in the length of 19cm looks good.
10 October 2017
Frame is stable. No obvious sign of infection. TSF prescription improved the position of the transported fragment. Regenerate looks good.
Another TSF prescription was created today to dock the transported fragment. Clinically it looks that we need to go for further 2 inches - certainly not more.
31 October 2017
Docking almost completed. No major pin sites issues. There is still a scab at the level of the most proximal part of the transported fragment. Clinically no sign of infection.
21 November 2017
Good progress. Pin sites OK. Docking completed, but the "knee" flexion has not been achieved yet. Foot remains in the acceptable position.
05 December 2017
Slightly more bend in the "knee" than planned. Will correct it with a new prescription. Otherwise no major issues. Because of the "knee" bend, the leg is shorter and will lengthen it a bit more - 5-10mm.
Regenerate is doing well.
19 December 2017
Still struggling with the docking site. Since the last time we did not manage to improve the docking site position using TSF prescription. One of the possible reasons is that the rings were too close. To overcome the problem we inserted another larger TSF ring just below the distal ring in the hexapod and repositioned the struts to the new ring. This allowed us to use longer struts. At the same time we also introduced the "7th strut" to stabile the "TSF rattling".
Patient lengthened the leg for another 5 mm since the last appointment and I think that this is the length we are looking for at the moment.
Regenerate is stil weak but visible and I remain optimistic.
06 February 2018
Docking still not sorted. But we remain optimistic. Regenerate looks also very promising. Hopefully with the new TSF prescription we will compress the docking site. Soft tissue over the docking site is still not completely sorted.
06 March 2018
Regenerate and pins sites are OK, but the leg is quite swollen and painful. I only suspect that the pain is as a direct consequence of swelling.
In my experience the best treatment for significant swelling in frames is admission to hospital for elevation only. We can argue if this is the best utilization of hospital bed, but it really works. Cannot be achieved at home.
As you can see on the long leg film, the alignment distally has changed. The most effective way of tackling the problem is to change clickers for struts and than correct the deformity using TSF prescription.
13 March 2018
Patient was admitted as planned. The swelling came down instantly as expected after admission. Infectious diseases consultant was not happy to prescribe any antibiotics. As the leg improved quite a lot, although there was some discolourated skin and the front of the tibia, the patient was discharged home on Tuesday after the CT scan of the leg was done to look for any abscess or other cause for possible infection.
There was no sign of any obvious infection but it also showed quite a lot of callus in the docking site, which came as a quite a surprise. My main concern until now was how to get the docking site healed, but it looks that it is done. Great. If only I would know why it healed?
CT Scan whole leg - sagittal reconstructions
CT Scan whole leg - coronal reconstructions
20 March 2018
Skin changes have demarkated. Not clear what has caused the problem. Swelling is back. A few of the rings are quite tight.
26 March 2018
External fixator was adjusted. Too small rings were replaced. Crust over the docking site came of and exposed the bone underneath. Not great. Decortication of the exposed bone showed bleeding bone. Quite a bit more than what we would usually see. Skin defect at the anterior part of the shin is more or less the same. It is not getting bigger. Why it happened/occured, we don't know.
Plastic surgeons will cover the defect with a local muscle flap.
17 April 2018
Plastic surgeon has covered the defect with a local flap.
So far good progress.
Regenerate is getting stronger, healing of the docking site is still under question.
05 June 2018
Patient was seen in a clinic. No significant complaints.
17 July 2018
Wounds are healing well. No major pin site problem. There is a significant amount of calcifications present at the docking side. Regenerate is consolidating well.
04 September 2018
One of the ankle pins is loose. Removed. Otherwise wounds are still healing. Equinus-varus deformity in the ankle still significant and restricting walking.
Docking site looks healed on the X-ray below and regenerate looks stronger each time.
29 October 2018
Sudden pain in the ankle slowed down the physio. No obvious reason found. But the ankle is still in significant equinous and varus. Very stiff.
X-rays are surprisingly revealing possibility of non-union in the docking site despite previous sound signs of union.
15 January 2019
Ankle is still painful. Ulcers are healing but very slowly.
Regenerate is strong enough and will remove the distal two rings hoping that this will ease pain in the ankle and improve physiotherapy. Docking site looks promising, but we have been there before.
12 February 2019
Tibia has survived four weeks after removal of the distal part of frame. Still not clear about the docking site union.
My main concern at the moment is the ankle joint. As it was more or less from the beginning.
26 March 2019
Regenerate is stable and strong, but docking site is probably not healing. While the frame is still stable, I think we should probably take "holiday from frame" and then reassess.
Function of the foot remains a big problem.
Mr Matija Krkovic, MD, PhD
I am Consultant Orthopaedic Trauma Surgeon with special interest in Limb reconstructions and bone infections.