Management of Bone Defects in Revision Total Knee Arthroplasty with Use of a Stepped, Porous-Coated Metaphyseal Sleeve

Abstract

Background: Revision total knee arthroplasty is a costly operation associated with many challenges including bone loss in the distal end of the femur and proximal end of the tibia^1,2. Reconstruction of bone defects remains a difficult problem that may require more extensive reconstruction techniques to restore mechanical stability and ensure long-term fixation. Use of porous-coated metaphyseal sleeves is a modern technique to address bone deficiency in revision total knee arthroplasty^3,4. Midterm reports have shown excellent survivorship and osseointegration^5-7.

Description: The use of a porous-coated metaphyseal sleeve begins with intramedullary canal reaming to determine the diameter of the diaphyseal-engaging stem. Bone loss is assessed followed by broaching of the tibial and/or femoral metaphyses. Broaching continues until axial and rotational stability are achieved. The sleeve typically occupies most, if not all, of the proximal tibial and distal femoral cavitary osseous defects often encountered during revision total knee arthroplasty. However, a sleeve does not address all distal and posterior femoral condylar bone loss, for which augments are often required.

Alternatives: Previously described methods to address various bone deficiencies include use of morselized or structural bone-grafting, reinforcing screws within cement, metal augments, and metaphyseal cone fixation^8-17.

Rationale: Structural allografts or metal augments remain a suitable option for uncontained metaphyseal defects. Metaphyseal structural allografts may undergo stress-shielding, resorption, and late fracture. Metaphyseal sleeves offer long-term biologic fixation to host bone while creating a stable platform to receive a cemented femoral and/or tibial component⁷. This hybrid combination may provide mechanically protective properties to decrease the loads at the cement-bone interfaces and enhance loads to metaphyseal bone to ensure long-term implant fixation in the setting of substantial bone deficiencies^18-20.

Fig. 1

Intraoperative photograph demonstrating marking of the proximal part of the tibia in line with the intramedullary reaming rod for the cementless stem. This allows for proper centering of tibial sleeve broaches.

Fig. 2

Tibial sleeve broach set.

Fig. 3

Intraoperative photograph demonstrating tibial sleeve broaching in line with the previously placed mark in Figure 1.

Fig. 4

When axial and rotational stability are achieved with the broach, the impaction handle is detached and the top of the broach can be used as a guide to freshen the tibial resection.

Fig. 5-A

Fig. 5-B

Fig. 5-C

Fig. 5-D

Fig. 6

Intraoperative photograph outlining the transepicondylar axis (blue marks) to ensure proper rotation of the anteroposterior femoral cutting block.

Fig. 7-A

Example of rotation of the femoral sleeve compared with the femoral component following trialing and insertion of a locking set screw.

Fig. 7-B

Using a bird’s eye view, the surgeon must precisely replicate the rotation of the sleeve relative to the tibial or femoral components from the trial components when assembling the final tibial and femoral sleeves.

Fig. 7-C

Bird’s eye view of precisely replicated final femoral sleeve-femoral component rotation.

Fig. 7-D

Final and trial femoral constructs.

Fig. 8-A

Fig. 8-B

Fig. 8-C

Fig. 9-A

Fig. 9-B

Fig. 10-A

Preoperative anteroposterior radiograph of both knees. The left total knee replacement had evidence of distal femoral osteolysis (white arrow).

Fig. 10-B

Preoperative lateral radiograph of the left knee demonstrates evidence of radiolucent lines along the anterior flange and distal aspect of the femur suggestive of a loose femoral component.

Fig. 10-C

Fig. 10-D