[The post-traumatic arthritis - a challenge?].

Total knee replacement in patients with post-traumatic arthritis is not fundamentally different from total knee replacement in patients with primary arthritis. Because of a 10-times higher infection rate, ordinary surgical planning should be implemented by the best possible exclusion of site infection based on actual information. Extra-articular deformities have to be preoperatively identified and individually treated with either an incomplete or a complete intra-articular correction or a single or double correction osteotomy. The commonly found combination of a contracted knee joint and an insufficient ligament balancing can mask instabilities of the knee joint. Consequently the definitive grade of a constrained knee prosthesis can only be determined intraoperatively. Existing osseous defects can be addressed with autologous bone grafts left from the total knee arthroplasty. Depending on the osseous defective site and the grade of constraints, prosthesis stems may be necessary but so far no clear recommendation can be given for either a cemented or a cementless fixation of the stem. The approach to the knee joint should be guided according to existing scars in order to prevent wound healing disorders. Even given optimal surgical planning and an optimum procedure of total knee arthroplasty postoperative results of post-traumatic arthritis are significantly inferior to results of primary arthritis. Therefore it is important to induce the commonly younger patients to form realistic expectations.