Computer-assisted navigation in total knee arthroplasty without femoral hardware removal.

PURPOSE OF THE STUDY

The use of navigation applied to total knee arthroplasty in knees with femoral hardware retained has not been studied.

MATERIAL AND METHODS

We use navigation in six patients to implant a total knee arthroplasty while retaining the femoral hardware. The retained materials were screws in two cases, diaphyseal plates in another two, intramedullary nails in one and supracondylar tube/plate in another one. Preoperative knee scores were within the 46-66 range, whereas the functional scores were within 40-68. The coronal deformity varied between 30° varus and 5° valgus.

RESULTS

The final femoral mechanical axis was between 2° valgus and 3° varus; the axis of the limb was between 4° valgus and 3° varus. Knee scores improved in all cases, with scores between 75 and 90 points (p = 0.028); functional scores were between 64 and 90 points (p = 0.043).The final range of mobility was within the 70°-110° range, with a slight improvement over the preoperative status (p = 0.042). No complications have arisen throughout the follow-up (mean 16 months).

CONCLUSIONS

The use of navigation constitutes a good option in the treatment with total arthroplasties for patients with femoral hardware retained.