Guidelines for Complications of Cancer Treatment Vol VIII Part B

In contrast, articulating spacers permit more joint motion andcan improve function prior to the second-stage reimplantation.From a technical perspective, improved joint function anddecreased scar formation after resection arthroplasty canfacilitate exposure during reimplantation. Although thedistinction between articulating and nonarticulating spacersis somewhat controversial, use of a well-molded, well-fittedarticulating spacer that restores soft-tissue tension and allowsa greater degree of joint motion has been reported to have abetter outcome than use of a nonarticulating spacer, whichmay limit joint freedom 30 . As previously stated, articulatingspacers are practically difficult to fabricate for the knee butcould be used for the hip.The steps for carrying out the procedure are welldescribed 29 .The first-stage procedure involves completeremoval of the implant, all the infected surrounding tissues,any scar tissue, and as much intramedullary cement as possible.If the prosthesis was not loose then approximately 1 cm ofbone was removed from the junction of the bone with theprosthesis to allow the prosthesis to be jacked out using adistractor. In most patients the prosthesis was loose and couldbe removed easily. The thick fibrous layer around the prosthesiswas removed along with the adjacent scar tissue that oftenwas edematous. Care was taken in revisions around the kneebecause this scar tissue often was in intimate contact with thepopliteal vessels or the posterior tibial vessels and nerve, andall of these structures are at risk during this procedure. Theintramedullary cement is removed using appropriate extractiontechniques that may include the use of chisels, drills, andultrasonic extractors. In most patients it proved impossible toremove all the cement as it had fanned out beyond the tip ofthe intramedullary stem in the metaphysis of the bone. Providedthe cement was not obviously loose or infected, thisimperfection in technique was accepted. One of the key110