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    Complex Femoral Reconstruction in Revision Total Knee Arthroplasty

    A 74-year-old total knee arthroplasty patient presents with recurrent aseptic loosening of cemented femoral component. She has already undergone 4 attempts at revision/salvage arthroplasty using fully cemented hinged prostheses, with no success. What would be the best option for achieving durable femoral reconstruction in this patient?


    Authors

    R. Andrew Henderson, MD, MSc, and Matthew S. Austin, MD

    Introduction

    Aseptic component loosening is a common contemporary reason for failure after total knee arthroplasty (TKA) [1,2].

    Biologic fixation (with highly porous metals, for example) has shown excellent mid-term results for obtaining metaphyseal fixation in revision TKA [3,4]. However, little has been published on obtaining biologic fixation within the diaphysis for cases with extremely deficient femoral or tibial bone stock.

    In a re-revision arthroplasty, loosening of long-stem or cemented implants on either the femoral or the tibial side can present multiple challenges when considering further attempts at reconstruction. These reconstructions are difficult to accomplish successfully due to:

    • Hardware removal
    • Cement extraction
    • Limitations in native bone stock available for purchase with press-fit implants
    • Attempts at repeated cementation

    In this report, we present a unique case of harnessing biologic diaphyseal fixation in the face of multiple aseptically failed attempts at fully cemented femoral reconstruction.

    Case Presentation

    A 74-year-old healthy female was referred to our department for consideration of revision left TKA. Her index arthroplasty 19 years earlier had failed due to early postoperative infection. She underwent successful 2-stage exchange at the time, and had no further septic complications.

    Unfortunately, she went on to develop recurrent loosening of her femoral component, with 4 subsequent attempts at revision/salvage arthroplasty using fully cemented hinged prostheses.

    The most recent fully cemented femoral reconstruction was completed 4 years prior to her consultation with our team. She had done well for approximately 12 months before recurrence of her thigh pain.

    All infectious workups had been negative for the prior 15 years, including multiple intraoperative specimens with each attempted reconstruction.

    History and Physical

    • Left thigh and knee pain of 3 years’ duration
    • Prior ipsilateral femoral neck fracture treated with 3 cannulated screws
    • No fevers or chills
    • Range of motion 0 to 95 degrees of flexion, limited by thigh pain
    • Well-healed longitudinal incision; no erythema, warmth, or palpable effusion
    • No tenderness over the tibia
    • Stable to varus/valgus stress
    • Palpable pedal pulses

    Laboratory Tests

    • Erythrocyte sedimentation rate: 29 mm/hour
    • C-reactive protein: 1.6mg/L
    • Aspirate: 20 mL of serous yellow fluid; 300 white blood cells per cubic millimeter; 16% polymorphonuclear leukocytes; culture negative
    • Negative alpha defensin test

    Imaging – Radiographs

    • Grossly loose fully cemented femoral component
    • Ectatic/limited distal femoral bone stock
    • Well-fixed and appropriately positioned tibial component (Figure 1)


    Figure 1. Preoperative radiographs showing the presence of rotating hinge prosthesis with grossly loose femoral component and ipsilateral hardware in the femoral neck, with approximately 9 cm of intact cortical bone.

    Diagnosis

    • Recurrently failed revision TKA due to aseptic femoral component loosening of a stemmed, fully cemented prosthesis

    Treatment

    • After consideration and discussion with the patient regarding the risks of attempted salvage reconstruction, we recommended that she undergo full explant of the existing hardware and conversion to a tumor-type prosthesis with compatible cylindrical hydroxyapatite-coated diaphyseal stem designs. We believed bone ingrowth was the best hope of achieving durable fixation.
    • Intraoperatively, the femoral component was found to be grossly loose and was removed quite easily after appropriate exposure of the joint.
    • The tibial component was found to be well fixed. Osteotomes and a micro-sagittal saw were used at the cement-implant interface to allow for removal of the prosthesis.
    • After successful removal of the tray, an ultrasonic device was used for extraction of retained diaphyseal cement.
    • There was significant proximal tibial bone loss as a result of the explant of the tibial tray, although the extensor mechanism and tibial tubercle remained intact and in continuity with the tibial diaphysis.
    • The implant system used in this reconstruction has modular stems that could, in theory, have been used on the tibial side as well. However, the patient had never had a problem with tibial tray loosening and her diaphyseal tibial bone appeared quite healthy compared with her distal femur. We therefore opted for more standard cemented fixation on the tibial side.
    • In considering reconstruction, the distal femur was resected at the level of mid-diaphysis to enable cortical femoral reaming and stem placement. Distally, it was reconstructed with an appropriate-length tumor-type prosthesis (chosen based on preoperative templating).
    • A small mating proximal tibial replacement was selected and potted within the remnant proximal tibia to allow salvage of the tibial tubercle and native extensor mechanism.
    • At early clinical follow up, the patient was doing well (Figure 2).

    Figure 2. Postoperative radiographs showcasing utilization of the intact diaphyseal bone for press-fit biologic fixation of the femoral component in a tumor-type prosthesis.

    Discussion

    This case serves to highlight several points about complex re-revision TKA.

    • Consider the use of biologic fixation in the face of multiple failed attempts at cementing stemmed femoral or tibial components.
    • Prior to undertaking such a reconstruction, investigate all possible alternatives for reconstruction, both within 1manufacturer and across the spectrum of available manufacturers.

    Surgical Pearls

    • Exposure of the proximal femur for ensuring adequate fixation is critical to obtaining a proper press fit. We accomplished this by cutting and meticulously excising the ectatic distal femur from the remnant soft tissue envelope, which then allowed the reconstruction to proceed quickly.
    • Although this patient had a well-fixed, fully cemented tibial component, it had to be removed to mate with the distal femoral replacement option that we had chosen, which was from a different manufacturer. Removing the tibial component was felt to be the patient’s best option for a durable femoral reconstruction, the lack of which was the source of her multiple prior failed reconstructions. The potential for achieving durable fixation far outweighed the possible morbidity of removing a well-fixed tibial component in this patient.
    • Once the tibial tray had been extracted, the bone loss was treated with a small proximal tibial replacement potted within the native tibial tubercle to allow maintenance of her native extensor mechanism. This is an option to consider in the appropriate setting and patient bone anatomy.
    • If there had been even less bone available for biologic fixation on the femoral side, or if we had opted to resect the prior cemented and ectactic bone, one could consider an alternative implant system that replaces the diaphyseal and distal femur in patients with severe bone loss, still enabling biologic fixation.

    Author Information

    R. Andrew Henderson, MD, MSc, is an orthopaedic surgery fellow at The Rothman Institute, Philadelphia, Pennsylvania. Matthew S. Austin, MD, is Adult Reconstruction Division Chief and Adult Reconstruction Fellowship Director at The Rothman Institute, Philadelphia, Pennsylvania.

    Adult Reconstruction Section Editor, Rothman Institute Grand Rounds

    Antonia F. Chen, MD, MBA

    References

    1. Sharkey PF, Lichstein PM, Shen C, Tokarski AT, Parvizi J. Why are total knee arthroplasties failing today—has anything changed after 10 years? J Arthroplasty 2014 Sep; 29(9): 1774-8.
    2. [Sharkey PF, Hozack WJ, Rothman RH, Shastri S, Jacoby SM. Insall Award Paper. Why are total knee arthroplasties failing today? Clin Orthop Relat Res. 2002 Nov; (404): 7-13.
    3. Girerd D, Parratte S, Lunebourg A, et al. Total knee arthroplasty revision with trabecular tantalum cones: preliminary retrospective study of 51 patients from two centres with a minimal 2-year follow-up. Orthop Traumatol Surg Res. 2016 Jun;102(4): 429-33.
    4. Sculco PK, Abdel MP, Hanssen AD, Lewallen DG.  The management of bone loss in revision total knee arthroplasty: rebuild, reinforce, and augment. Bone Joint J. 2016 Jan;98-B(1 suppl A): 120-4.