[Knee arthroplasty in patients with posttraumatic arthritis].

Arthroplasty in patients with posttraumatic arthritis can be challenging due to joint instability, malalignment, osseous defects, non-union, contracture, scarring, low-grade infections and pathologies of the patellofemoral joint. Detailed preoperative planning is recommended concerning incisions, soft tissue management, osseous reconstruction, hardware removal, potential infections and type of prosthesis (e.g. type of constraint, stems and augments). Severe difficulties can occur with exposure of the knee with respect to the extensor mechanism so that quadriceps snip or osteotomy of the tibial tuberosity may be necessary. Postoperative functional results are inferior to arthroplasty for atraumatic gonarthritis. Patients are at increased risk for intraoperative and postoperative complications (e.g. infections, instability, loosening and patellofemoral problems). Reconstructive alternatives (e.g. osteotomy, ligament reconstruction and cartilage repair) should always be considered especially in younger patients; however, most patients show a significant improvement in function and relief of pain after arthroplasty for posttraumatic gonarthritis.