I'd try to remove all the remaining cement. Bacterial survival in the interface between cement and bone has been described. 

See this link

http://www.bjj.boneandjoint.org.uk/content/87-B/2/272.full

Of course, Dr. Berjano, complete cement removal is the ideal case. Bacterial survival in the interfacial gap between cement and bone was described. My question tackles those cement parts which are closely stuck on the bone, i.e. where no gap exists and where the probability of bone breakage is high. In similar cases I would rather prefer to repeat the debridement in several weeks if the infection persists (laboratory data, sinus,etc) than unfortunately causing breakage of the  bone and facing the situation of fracture treatment under the conditions of infection. 

You can preview contaminated area by PET and demonstrate it by multiple microbiological assays. We eradicate a deep infection of a total femur implant by leaving the tibial cemented metal component inside. Before reimplantation we demonstrate eradication by VAC therapy. One year follow up is good.

Dear Dr. Gallo, please, could you explain the role of VAC therapy in infected THR. You said "... before reimplantation we demonstrate eradication by VAC therapy..." ? In my opinion VAC therapy is contraindicated in cases with deep infection. Do you apply VAC therapy also in infected THR without removal of implants ? Any experience ?

The removal of all the cement is of strenuous importance if we want to succeed in the treatment of infection.

The better way to make this si the practise of a lateral femorotomy which allows a panoramic vue of the inside of the canal and a safe procedure to remove the residual cement.

The reconstruction demands a long stem to assure stability and cerclages to closethefemorotomy.It'saverueffectiveprocedure

I agree with Dr Basso. In case of poor bone quality and serious doubt about the chance to remove cement without causing fractures, a planned diaphysotomy and revision with the Wagner's technique and implant can be a safe way to overcome the difficulties of cement removal. This increases the aggressiveness of surgery and requires the use of specific implants (the Wagner stem) and respecting some rules (leaving muscle insertions to the detached bone -by doing in part a trans-muscular osteotomy with chisels-, leaving a transversal section of bone that includes 2/3 to 3/4 of the circumference in order to avoid instability, good cable wire fixation, enough distal fixation of the prosthesis. 

Yes, I agree. Like for every sophisticated technique, it demands to learn it properly to reech the goal withoit sever problem

Thank you, Dr. Basso and Dr. Berjano, for your responses . To remove without incidents a well cemented but infected  femoral stem, you need a wide opening through lateral femorotomy with a pedunculated (mm. glutei and m. vastus lateralis) femoral flap. It is a good idea to plan this major procedure before surgery.

We prefer modular revision stem (Revitan Straight-Zimmer) which allows choosing appropriate implants with metaphyseal-diaphyseal, short diaphyseal or long diaphyseal fixation according to the individual case. The modularity ensures a good primary stability (proximal or distal). In the case of femorotomy with a femoral flap, we use a long stem assembly with distal fixation.  We rarely  use chisels and prefer oscillating saws because of the poor quality of the bone and the risk of breakage.

Regards  ! 

to Panayot Tanchev

We successfully used VAC therapy in an infected total femur implant.

We removed total femur but leaving tibial cemented implant and eradicated the deep infection, then reimplanted the total femur. We have a 12 months follow up.

If the cement is removed completely using a Wagner approach the femoral osteotomy has to be fixed by cerclage wires. Are the cerclage-wires also extraneous material which maintain the infection by building a bacterial biofilm?

Thank you, Dr. Novak, for your answer and the additional question. You tackle the core around which all this discussion is about. Of course the wires or other osteosynthesis device can maintain the infection by building a bacterial biofilm. This is obviously  valid for the bone cement left in the canal.

However, fracture of the femur during surgery for infected THR is a catastrophic situation. That is why I still insist that some well fixed parts of bone cement should be left in situ in the femoral canal. Facing a second debridement seems to be a less evil than femoral fracture in the condition of virulent deep infection.