RESUMO Objetivo para pacientes com deformidade extra-articular (EAD), é difícil alcançar o alinhamento adequado após a artroplastia total do joelho (TKA) por causa de um eixo anatômico alterado e marcos distorcidos. Somente foram relatadas apenas séries de casos quanto à utilidade do sistema de navegação assistido por computador para TKA com a EAD até agora. Neste estudo, tentamos comparar resultados em TKA com EAD com e sem navegação. Métodos Quatorze pacientes com osteoartrite com EAD devido a maluniões ou operações de fratura anteriores foram avaliadas. 7 TKAs foram realizados com navegação (navegação em grupo) e outros 7 TKAs foram realizados sem ele (manual de grupo). Antes e dpois anos após a cirurgia, os desfechos clínicos e radiográficos foram comparados. Resultados O resultado médio da função Knee Society pós-operatório foi significativamente maior na navegação do grupo do que no manual do grupo. Não houve diferença significativa na amplitude de movimento pós-operatória e na pontuação do joelho na joia. A taxa de outliers em resultados radiográficos tende a ser menor na navegação do grupo do que no manual do grupo. Conclusão foram obtidos melhores resultados clínicos na navegação em grupo. O sistema de navegação assistido por computador é útil em TKA para pacientes com EAD. Nível de Evidência III; Estudo de caso-controle.

ABSTRACT Objective It is difficult to achieve proper alignment after total knee arthroplasty (TKA) in patients with extra-articular deformity (EAD) because of altered anatomical axis and distorted landmarks. As of this writing, only case series have been reported with regard to the usefulness of computer-assisted navigation systems for TKA with EAD. This study therefore compared outcomes in TKA with EAD, with and without navigation. Methods Fourteen osteoarthritis patients with EAD due to previous fracture malunion or operations were assessed. Seven TKAs were performed with navigation (navigation group) and another 7 were performed without navigation (manual group). Clinical and radiographic outcomes were compared before and two years after surgery. Results The mean postoperative Knee Society function score was significantly higher in the navigation group. No significant difference was found in postoperative range of motion and Knee Society knee score. The rate of outliers in radiographic outcomes tended to be lower in the navigation group. Conclusion Better clinical outcomes were achieved in cases in which navigation was used. Computer-assisted navigation is useful in TKA for patients with EAD. Level of Evidence III; Case control study.

ABSTRACT Objective: To determine whether the second-generation constrained condylar prosthesis provided satisfactory results in revision total knee arthroplasty. Methods: A series of 41 cases of revision total knee arthroplasty using the second-generation constrained condylar knee prosthesis was reviewed. The series comprised 7 men and 34 women with a mean age of 73.2 years. The original diagnosis was predominantly osteoarthritis. The most common reason for revision surgery was aseptic loosening. The mean interval between the primary and revision surgeries was 66.4 months. The mean follow-up period was 49.4 months. Results: The mean Knee Society knee score improved from 43.8 to 82.9 after revision surgery, the mean Knee Society function score improved from 37.1 to 79.2; the range of motion improved from 95.6° to 105.6° and the radiological femorotibial alignment improved from 181.4° (varus 6.4°) to 174.9° (valgus 0.1°), on average (p<0.001 at all items). Conclusion: Revision total knee arthroplasty with the use of the second-generation constrained condylar knee prosthesis yielded reproducible clinical success. Level of Evidence IV, Case series.