Outcomes After Revision Total Knee Arthroplasty
The literature supporting decision-making for revision total knee arthroplasty is less developed and less rigorous than that for primary total knee arthroplasty.
Furthermore, the choices and strategies shown to be optimal for total knee arthroplasty are not always optimal for revision surgery, which carries a higher risk of complication and failure.
The following studies specifically address outcomes after revision total knee arthroplasty and are compared to our own outcomes in Guadeloupe.
The use of constrained condylar implants
is probably too common for revision total knee arthroplasty as there are often challenges to attaining optimal stability through the range of motion.
Kim and Kim
retrospectively studied the results of revision total knee arthroplasty in ninety-seven patients (114 knees) who had an average age of sixty-five years at the time of the index procedure.
Aseptic loosening, polyethylene wear, and infection were the reasons for revision in the majority of cases, and constrained condylar implants were used when the posterior cruciate ligament and either the medial or lateral collateral ligament was deficient.
Most implants were cemented in the metaphyseal region only, leaving the canal free of cement for a press fit : we use the same technique.
Patients were followed for an average of 7.2 years and were assessed with use of several knee scores and osteoarthritis indices.
The authors found that the ten-year survival rate, with revision or radiographic failure as the end point, was 96%. Five knees required repeat revision, and three knees sustained an extensor mechanism rupture.
As well as our own experience woud confirm it, this report suggested that constrained condylar implants can yield very successful outcomes for ten years after revision total knee arthroplasty, although surgeons must be vigilant after surgery in consideration of a higher complication rate.
Peters et al.
retrospectively studied the four-year results of 184 consecutive revision total knee arthroplasties that were performed with a modular, cementless, press-fit, fluted stem.
The most common reasons for revision were aseptic loosening and infection : same indications in Guadeloupe.
At the time of the most recent follow-up, there had been only fifteen failures (8%), including nine recurrent infections and four new cases of deep infection.
There were no repeat revisions for aseptic loosening and no cases of radiographic loosening.
Similar to the previous study, revision total knee arthroplasty with a metaphyseal cementing technique and a diaphyseal press-fit yielded excellent early to intermediate-term results.
Long and Scuderi
reviewed the outcomes of sixteen revision total knee arthroplasties involving the use of porous tantalum cones for defects in the tibia. At a minimum of two years of follow-up, there were no cases of mechanical failure or loosening of any of the cones. Two patients required cone removal because of recurrent infection.
It appears that early-term results are quite positive for tantalum augments as they exhibit dependable osseointegration characteristics. Long-term studies are necessary to determine their survival rate.
The efficacy of antibiotic-loaded bone cement
may differ when revision total knee arthroplasty is compared with primary total knee arthroplasty.
Chiu and Lin
studied the prophylactic effect of vancomycin-bearing cement (1 g of vancomycin per 40 g of cement) used during revision total knee arthroplasty. The authors conducted a prospective cohort study of 183 first-time revision total knee arthroplasties in patients without an infection.
Ninety-three procedures were performed with low-concentration antibiotic cement, and ninety procedures were performed with standard cement.
All revisions were performed in a room without ultraviolet light, laminar flow, or body-exhaust suits, and all patients received intravenous antibiotics preoperatively and for thirty-six hours after surgery.
At an average of eighty-nine months after revision total knee arthroplasty, there had been six deep infections (7%) in the control group and no infections in the vancomycin-loaded cement group.
The difference was significant (p = 0.0130).
The authors recommended the use of low-dose antibiotic-laden cement for revision total knee arthroplasty but pointed out the need for larger studies.
