BACKGROUND:
Knee arthrodesis can be an effective treatment option for relieving pain
and restoring some function after the failure of a total knee arthroplasty as
the result of infection. The purpose of the present study was to review the
outcome of a staged approach for arthrodesis of the knee with a long
intramedullary nail after the failure of a total knee arthroplasty as the
result of infection.
METHODS:
We reviewed the results for twelve patients who underwent knee arthrodesis
after the removal of a prosthesis because of infection. The study group
included seven women and five men who had an average age of sixty-eight years
at the time of the arthrodesis. All patients were managed with a staged
protocol. Implant removal, débridement, and insertion of antibiotic
cement spacers was followed by the administration of systemic antibiotics.
Provided that clinical and laboratory data suggested eradication of the
infection, arthrodesis of the affected knee with use of a long intramedullary
nail was carried out. Clinical and laboratory evaluation and radiographic
analysis were performed after an average duration of follow-up of 4.1
years.
RESULTS:
Solid union was achieved in ten of the twelve knees. The average time to
union was 5.5 months. One patient had an above-the-knee amputation because of
recurrence of infection. In another patient, nail breakage occurred three
years following implantation. The average limb-length discrepancy was 5.5 cm.
The mean Western Ontario and McMaster Universities Osteoarthritis Index
(WOMAC) score improved from 41 to 64 points. None of the seven patients who
underwent arthrodesis with a technique involving convex-to-concave reamers had
a complication, and the average time to union for these seven patients was
shorter than that for the remaining five patients (4.3 compared with 7.4
months).
CONCLUSIONS:
We believe that obtaining large surfaces of bleeding contact bone during
arthrodesis following staged treatment of an infection at the site of a failed
total knee arthroplasty contributes to stability and enhances bone-healing.
Staged arthrodesis with use of a long intramedullary nail and
convex-to-concave preparation of bone ends provided a painless functional gait
with low complication and reoperation rates in this challenging group of
patients.