Extramedullary femoral alignment system in total knee arthroplasty: Accuracy in relation of severity and different types of varus.

Abstract Objectives We assessed the accuracy of an extramedullary guide system for femoral component alignment in TKA. Methods We retrospectively analysed 87 total knee arthroplasties using a newly developed extramedullary guide system. Results Correct postoperative coronal plane femoral component, with deviation from neutral alignment by 3° or less, was found in 87% of the study population. The percentages were 100%, 91% and 79% for HKA of 0–3°, 3–10° and >10°respectively. Conclusion The correct use of the extramedullary guide system allows the restoration of the neutral mechanical axes of the lower limb, especially in cases of limited varus deformity.