Knee Arthrodesis with an Intramedullary Nail After Failed Total Knee Arthroplasty

INDICATIONS

 

• Limb salvage after failure of delayed exchange and re-implantation of infected total knee arthroplasty (TKA)

• Loss of extensor mechanism

• Bone loss after failed repeat re-implantation or posttraumatic osteoarthritis

  • Examination/Imaging

  • Arthrodesis should be preceded by any or all necessary treatments for infection (removal of implants, cement debris, and necrotic tissue) and implantation of an antibiotic cement spacer.

  • Anteroposterior (AP) and lateral plain films of the affected knee and entire lower extremity from hip to ankle are important.

  • The length of the femur and the tibia must be determined, and any unusual bowing or canal abnormalities must be identified.

  • • • The length of the femur and the tibia can be obtained from plain radiographs with a measuring template in place.

      • Alternatively, a computed tomography (CT) scan from the tip of the trochanter to the distal femur and then from the proximal tibia to the distal tibia can be used (Fig. 1).

    • CT scans are also helpful for identifying the narrowest portion of isthmus of the tibia, which is the dimension that limits the size of the nail.

      • The arthrodesis nail should extend from the tip of the greater trochanter to well within the isthmus of the distal tibia.

      • If there is distraction at the level of the knee, this amount of length should be taken into consideration with the final nail length.

    • Coronal CT scans can be used to identify the narrowest portion of the femoral canal (Fig. 2A) and the tibial canal (Fig. 2B) for measurement of intended nail diameter.

 

Surgical Anatomy

• Femoral and tibial canals must be without obstruction, such as fracture callus.
  • An osteotomy may be necessary to open the obliterated canal in the region of the fracture callus or to correct any deformity that would preclude successful nail placement.
  • The preoperative radiograph in Figure 3 demonstrates a small deformity of the distal femur. This deformity did not affect the procedure, but a more significant deformity would add to the complexity of the arthodesis.
• The femoral canal must be free of previously placed hardware or prostheses.

 

Positioning

• A radiolucent operating room table is required, with a single draped C-arm fluoroscopic unit.
• The patient is placed in the lateral (Fig. 4) or semi-lateral (“sloppy” lateral) position. Positioning devices are used both anteriorly and posteriorly.
• Prepping and draping resemble that for a hip arthoplasty procedure. However, the affected limb should be draped free from the gluteal region to the distal tibia to optimize positioning and maneuverability while the guide, reamer, and nail are passed.
• The leg is internally rotated to obtain radiographic views in multiple planes as needed.

 

Portals/Exposures

• This procedure can be carried out in three different ways.
  • The canals can be canulated from the knee. This involves retrograde guidewire placement in the femur, and anterograde guidewire placement in the tibia. This is our preferred method.

• The tibia can be exposed from the knee joint and the greater trochanteric entry site can be exposed through a typical incision at the greater trochanter similar to traditional anterograde femoral nailing.
• For both of these techniques, the femur and tibia are individually reamed in an anterograde fashion. Standard-length reamers are sufficient.
  • If no knee exposure or removal of a cement spacer at the knee is necessary, the entire procedure can be performed in an anterograde fashion. This is more difficult and requires the guidewire to successfully cross the knee joint in a blind fashion. Fluoroscopic surveillance is particularly important, and extra-long reamers are required.
• For all three techniques, an extra-long guidewire is necessary to have the wire in proper position to guide correct passage of the nail.

Procedure

Step 1

• Perform an anterior approach to the knee joint to remove any spacer block (Fig. 5) and to identify the distal femur and proximal tibial metaphyseal regions.

 

The guidewire should then be easily advanced in a retrograde fashion up the femur into the greater trochanteric region (Fig. 6A), as monitored fluoroscopically (Fig. 6B). Once it gets to the region of the greater trochanter in a safe position (not in the femoral neck), it is gently advanced through the trochanter with gentle mallet blows. It can be retrieved using a small incision in the buttocks region (Fig. 6C).

 

• Alternatively, if the guidewire cannot be placed in a retrograde fashion, a standard trochanteric approach is made and the proximal femur is canulated beginning with an awl or starting reamer over a guide pin.

• The guidewire is passed into the femoral canal and retrieved at the knee joint.

• The tibial canal can be reamed in an anterograde fashion with or without a guidewire. The tibia should be reamed well into the diaphysis, while keeping at least 8 cm above the distal tibial margin.

• With the guidewire in place, the femoral canal is

  reamed (anterograde) to 2 mm larger than the intended nail diameter.

• The guidewire is taken across the knee joint, introduced into the proximal tibia, and passed to the distal one third of the tibia.

   

 

• Step 2
• Use of a long intramedullary nail with a 5° valgus bend and flexion angle of 5° is preferable.
• With the guidewire in place in the femur and tibia, the nail is introduced in the greater trochanter.
• Gentle blows should advance the nail into the femur diaphysis. This should be viewed fluoroscopically.
• If the nail does not easily pass into the femur, the femur can be reamed an additional 1 mm. This will not compromise fixation because a proximal interlocking screw will be used.
• Once the nail emerges from the distal femur, the tibia is held in the desired position, especially rotational position, as the nail is advanced into the tibial metaphysis (Fig. 7A).
• Ensure that the tibia is positioned under the femur on both the AP and lateral fluoroscopic views
• Once the rod enters the proximal tibial diaphysis, the tibial rotation must be finalized. As the rod enters the tibial diaphysis, the rotational position becomes fixed.
• Step 3
• Proximal interlock of the nail is performed near the greater trochanter (Fig. 8A and 8B).
• · 
  Final alignment and fusion site distraction are assessed radiographically (Fig. 9A and 9B).
• ·  Coverage of the proximal nail hole is left to the discretion of the surgeon.
• Step 4
• ·  Close the incision over the trochanter and anterior knee.
•  
• 
• Postoperative Care and Expected Outcomes
  • Patient advanced to immediate weight bearing as tolerated.

Evidence

Bargiotas K, Wohhlrab D, Sewecke JJ, Lavinge G, DeMeo PJ, Sotereanos NG. Arthrodesis of the knee with a long intramedullary nail following the failure of a total knee arthroplasty as the result of infection: surgical technique. J Bone Joint Surg Am. 2007;89(Suppl 2):103-10.

 

Reaming of the distal femur and proximal tibia to achieve greater bone apposition is described in this article.

 

Donley BG, Matthews LS, Kaufer H. Arthrodesis of the knee with an intramedullary nail. J Bone Joint Surg Am. 1991;73:907-13.

 

These authors are among the first to publish a series on the success of knee arthrodesis utilizing an intramedullary nail.

 

Ellingsen DE, Rand JA. Intramedullary arthrodesis of the knee after failed total knee arthroplasty. J Bone Joint Surg Am. 1994;76:870-7.

 

These authors report improved success over other contemporary techniques of knee arthrodesis when an intramedullary nail was used.

 

Incavo SJ, Lilly JW, Bartlett CS, Churchill DL. Arthrodesis of the knee: experience with intramedullary nailing. J Arthroplasty. 2000;15:871-6.

 

This is the largest arthrodesis series using an intramedullary nail which describes the authors’ technique which resulted in a 100% fusion rate.

 

Waldman BJ, Mont MA, Payman KR, Freiberg AA, Windsor RE, Sculco TP, Hungerford DS. Infected total knee arthroplasty treated with arthrodesis using a modular nail. Clin Orthop. 1999;(367):230-7.

 

These authors describe their experience with a modular fusion nail assembled at the knee.

ESGRE