Review Question - QID 219777

TKA Revision Technique - Bone Defect Reconstruction Reconstruction is addressed with: QID: 219777 (SBQ24HK.11)

QID 219777 (Type "219777" in App Search)

A 70-year-old man presents to the clinic with complaints of 2 years of increasing shin pain that is worse with activity. He underwent revision of his total knee arthroplasty 3 years prior by another surgeon. On exam, he has no swelling and is non-tender about the knee. He points to the area marked in Figure A when describing his pain. Knee radiographs obtained in the clinic are demonstrated in Figure B. His erythrocyte sedimentation rate and C-reactive protein levels are within normal limits. Which of the following surgical considerations may have prevented his problem?

Type & Select Correct Answer

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Use of a modular, mobile bearing hinge prosthesis

10%

66/670

Revision to an antibiotic impregnated cement spacer

8/670

Use of fully cemented stem fixation

48%

324/670

Initiation of teriparatide at postoperative week 2

15/670

Use of a short press-fit stem

38%

252/670

Select Answer to see Preferred Response

The patient is complaining of end-of-stem pain, likely secondary to his press-fit diaphyseal stem fixation, which could have been avoided by utilizing a fully cemented stem (Answer 3).

When bypassing metaphyseal bone loss in the setting of revision total knee arthroplasty, it is often required to utilize stem fixation. Two of the most common styles of tibial revision stem techniques include fully cemented metaphyseal stem fixation and "hybrid" fixation (cement under the tibial tray, press fit diaphyseal stem). Hybrid techniques with press-fit diaphyseal stem fixation are associated with an increased risk of periprosthetic fracture and "end-of-stem" pain, theorized to be caused by the elastic modulus mismatch of the implant stem and cortical bone.

Ayekoloye et al. provide a review of fully cemented and hybrid techniques for stemmed revision total knee arthroplasty. Both fully cemented and hybrid techniques have advantages and disadvantages, and the optimal implant technique remains controversial. Diaphyseal engaging stems present a risk of end-of-stem pain. Multiple comparative studies have been reviewed between the two techniques, and no significant clinical outcome or revision risk differences were found.

Edwards et al. performed a retrospective review of 102 cemented and 126 press-fit stems in two-stage revision total knee arthroplasty. Re-revision rates for aseptic loosening and reinfection rates were equivalent. Post-hoc analysis demonstrated that cemented stems had a higher rate of radiographic loosening but no differences in clinical outcomes.

Barrack et al. reviewed a retrospective case series of 143 stemmed press-fit revision total knee arthroplasties utilizing solid cobalt chrome stems and slotted titanium stems. Solid cobalt chrome diaphyseal engaging stems were associated with an increased risk of end-of-stem pain.

Figure A demonstrates a postoperative limb with the anterior pretibial area marked. Figure B presents an AP radiograph of a stemmed revision total knee arthroplasty with a hybrid fixation technique.

Incorrect Answers:
Answer 1: Use of a modular, mobile-bearing hinge prosthesis would not prevent end-of-stem pain.
Answer 2: Index revision to an antibiotic spacer and subsequent two-stage revision is not indicated in the absence of infection and would not change outcomes regarding end-of-stem pain.
Answer 4: Initiation of teriparatide would not prevent end-of-stem pain as the etiology of end-of-stem pain is mechanical.
Answer 5: Press-fit stem fixation of revision total knee arthroplasty is associated with increased end-of-stem pain. The length of the stem would not mitigate the cortical stem elasticity mismatch.