Comminuted distal femoral fractures are not easy fractures to treat and heal. If they are open fractures the problem is even bigger. Those fractures are usually seen in the young, active male population, but can happen in the senior age group as well.
I am presenting a case of an open comminuted distal femoral fracture with a bone defect in the region between 8-10 cm (it depends on how it is measured and if you accept any leg shortening as a result of it). Injury happened as a result of an RTA.
The injury happened in March 2014. Luckily, it was an isolated injury which left us with more space for treatment. After initial stabilisation of the patient and stabilisation of the femur, with a spanning Ex-fix, we proceeded with internal fixation of the femur using LISS plate and bone cement to fill the defect after the debridement of the bone. Bone cement was put in in layers and layers separated with a seeweed based type of material, to enable an easier removal when performing the second stage of the Masquelet technique. In-between layers, but also around the cement we put reabsorb-able beads with antibiotics to sterilise the wound.
At this stage I was really optimistic. The plan was to continue with physiotherapy and follow-up as standard. Unfortunately there was no significant improvement in callus (bone graft) growth and X-rays 1 year post injury showed a few broken screws (yellow arrows) and no healing of the fracture.
Slow progress of new bone growth and broken screws convinced us to revise it to another distal femoral locking plate, combined with proximal femoral corticotomy with an aim to use callus distraction method, to fill the gap in the femur.
At that point we also had a long discussion with the patient, whether to proceed with callus distraction or distal femoral replacement. The patient decided to go for the distraction option, as we gave him an estimate of the knee function post distal femoral replacement in the region of 70-80% of a standard primary total knee replacement but also couldn't guarantee him infection free outcome.
We decided not to wait any longer as it was likely that the other screws will fail and everything will fall apart. Revision surgery with a removal of the existing metalwork including broken screws (there was also one broken screw in the proximal fragment which was not visible on the X-ray) was done a few days after previous appointment (as soon as the patient was prepared for the surgery).
The patient was closely monitored throughout. One of the problems was an early pin site infection, mainly due to the monorail being too close to the skin (proximal pins bent after lenghthening started) and proper pin site care was not possible. This problem was addressed by adjusting the position of the monorail. Ever since then the pin sites have remained dry, the patient is also on oral antibiotics and is coping well.
End of June 2015, X-rays showed good callus formation (yellow arrow) and a reabsorption of the bone substitute loaded with the antibiotics (expected). Pin sites were dry, patient was generally well with no signs of infection. There was no biological activity present at the level of the defect.
On 18 August 2015, there were no changes in the patient's condition. He continued with bone transport as planned. X-rays showed a significant improvement in the callus (yellow arrow) but also an impressive new bone formation, at the level of the defect (blue arrow). This was certainly not seen on the X-ray above, which was taken 6 weeks before.
22 September 2015
No major pin site problems. I certainly expected significant complications, at least related to the pin sites. But not. Lucky. Regular dressing did the job.
Patient still on suppression antibiotics. Range of movement in the knee is maintained - at least 90 deg of flexion, which is surprise for me.
Latest X-rays are below. Excellent regenerate (yellow arrow) with further deflection of the fragment but also additional bone formation in the medial side (blue arrow) in the docking site. Cannot really explain it.
28 September 2015
We took patient to the theatre today and locked the fragment and removed the ex-fix. It was significantly more force required to move the fragment than I anticipated. Probably because of the healing docking point on the medial side as usually not that much force is required (bent screws on the X-rays). Everything else went according to the plan.
I hope that the images are self-explanatory. If you have any questions do not hesitate to contact me over the email.
09 October 2015
Follow up two weeks post removal of Ex-fix and docking of the transported fragment. All wounds healed, no sign of infection. Patient is well in himself. X-rays are self-explanatory. Very surprising extensive callus formation on the medial side of the docking site as described previously.
17 November 2015
Looking at the X-ray below you can understand my disappointment. But patient's discomfort as well. Not even 6 weeks post removal of the Ex-Fix plate bent and broke. In my opinion there are some serious flaws in the design of the plates. We are certainly not using them any more for the similar tasks.
19 November 2015
Patient was taken to the theatre for re-fixation. I was reluctant to remove the broken plate on the distal femur. Finally we came to the plan to remove only the proximal part of the broken plate and than span the distraction site with a new plate where holes will match with the existing plate. We were lucky and manage to get bot plates perfectly overlapping allowing us to get 4 bi-cortical locking screws into the mid-fragment. Procedure was done percutaneously. Blood supply to the area was extremely good (probably result of the corticotomy).
As you can see above we accepted some shortening (around 1 cm) and will not try to restore the length due to the possible further complication. At the moment will heal the femur and than replace the knee as soon as it will be safe to do so.
Patient will continue with weight bearing as tolerated and exercises to keep his left knee and left hip mobile. Further follow up will be organised in 4 weeks.
07 March 2016
X-rays bellow are more then self explanatory. Frustration does't end.
11 April 2016
CT scan did not confirm the union of the docking site. Broken plates were removed and will be analysed further for the reason of failure. Personally I believe that the working length of the plate was sufficient and that the failure cannot be attributed to the technical error.
Plate was exchanged for AxSOS 3 Stryker distal femoral plate. Shortening of the leg was accepted, as well as the lack of the healing in the docking site.
07 June 2016
Finally improvement. So pleased. Patient walked into examination room with one crutch but can also walk unaided on shorter distances. No significant pain from his left knee. All wounds healed. No sign of infection.
X-rays below confirm further consolidation of regenerate but also quite surprisingly new bone formation at the level of the non-union. I certainly did not expect much happening at the non-union level. Hopefully I was wrong.
Left leg is shorter 4-6cm. The shortening is compensated by shoe raise.
20 September 2016
Patient walks with one crutch outdoors and no support indoors. All wound healed no sign of infection. No major pain. Interestingly, knee pain is not causing any major issue.
X-rays below show full consolidation of the corticotomy site but also further healing in the docking site.
20 December 2016
All going well. Patient happy with the progress. Pain, if any, well under control. Does not want to discuss a total knee replacement.
X-rays suggest further consolidation of the fracture/docking site, despite all the problems in the past. No loose screws in the distal femur.
20 June 2017
Some swelling at the level of the proximal femur few days ago after a few miles walk. Subsided gradually in two days. Very likely the plate is causing an irritation to the trochanteric bursa. Otherwise no major changes in pain or mobility.
X-rays are unchanged with very likely further healing at the "docking" site.
At the moment we decided not to do anything as the level of activities is relatively high and level of problems relatively low. We might shorten the plate should it continue to irritate.
Mr Matija Krkovic, MD, PhD
I am Consultant Orthopaedic Trauma Surgeon with special interest in Limb reconstructions and bone infections.