Flip Autograft Technique for Anterolateral Femoral Deficiency in Total Knee Arthroplasty

Abstract

Anterolateral bone loss of the femur within the trochlear groove presents a unique and rare issue in primary total knee arthroplasty (TKA). Unlike distal and posterior femur bone loss for which most contemporary TKA systems have modular augments, the same does not exist for anterolateral bone loss. We present a technique in which a patient's host bone from the standard distal femoral cuts was used to augment and provide a stable base for cementing of final femoral implants. Currently, the patient has 3-year follow-up with excellent results in terms of pain control with no evidence of component failure on the most recent radiographs. This technique provides a simple solution to a complex problem within primary TKA.

Keywords: Anterolateral femoral deficiency; Augmentation in total knee arthroplasty; Flip autograft; Patellofemoral arthritis; Total knee arthroplasty.

Figure 1

Preoperative (a) anteroposterior, (b) lateral, and (c) sunrise views of the right knee demonstrate a valgus knee tricompartmental osteoarthritis, with chronic changes to the patella and trochlea (left total knee performed by a surgeon at an outside hospital).

Figure 2

After initial femoral sizing and cuts, there was significant unsupported area on the anterior femur under the flange.

Figure 3

Photos demonstrating the intraoperative autograft technique. (a) The resected posterior femoral condylar bone that would be used for transplantation. (b) Initial conformity of autograft. (c) Two 4.0 fully threaded cancellous screws secure autograft into place.

Figure 4

After placement and proper shaping of the autograft, there is now a stable base for the anterior flange of the femoral component.

Figure 5

Clinical photo of hypoplastic and fragmented patella. The image shows the area of fibrous union. Overall, patella was very thin, and decision for retaining native patella was made to preserve existing bone stock and extensor mechanism.

Figure 6

Three-year follow-up radiographs. (a) Lateral, (b) anteroposterior, and (c) sunrise demonstrate well-fixed posterior stabilized femoral component in good position with the main patella fragment maintaining excellent tracking within the trochlea.