Total knee reconstruction without posterior stabilization in rheumatoid arthritis patients

Objectives: to present the results with posterior cruciate ligament-retaining total knee arthroplasty in rheumatoid arthritis (RA) patients. Background: Total knee replacement in RA patients has many particularities. One of them is the difficulty of obtaining a proper ligamentous balance.Methods: 24 RA patients were followed for a 5-year period after posterior cruciate ligament-retaining total knee arthroplasty. Clinical assessments analyzed general health status by using Hospital for Special Surgery Knee Evaluation Form (HSSKEF) and mediolateral and anteroposterior ligament stability by using varus-valgus and posterior drawer tests. Radiological assessments evaluated axial alignment, size and position of components, radiolucent lines in anteroposterior and lateral standard views, integrity of the posterior cruciate ligament on lateral view X-ray at 45 degrees of flexion.Results: the mean HSSKEF score increased from 32 to 84 points at the end of follow-up. Preoperative mean range of motion was 60 degrees; postoperative mean range of motion was of 105 degrees, with significant statistical difference (p<0.05). The mean femoral component axial deviation was 6 degrees. The tibial component had a mean axial deviation of 1 degree of varus. There were no radioluscency lines of more than 1mm. 21 patients had excellent results. None of the knees was unstable. Conclusion: posterior cruciate ligament-retaining total knee arthroplasty can be used in RA patients without excessive valgus deformity (over 15 degrees), providing thus sufficient stabilization. The outcomes re similar to those patients who followed a posterior stabilized endoprosthesis.