Management of the exposed total knee prosthesis, a six-year review

An exposed knee prosthesis is a limb threatening condition. Our unit manages such cases according to a multidisciplinary orthoplastic protocol. Whilst early prosthetic joint infection with dehiscence may be managed by Debridement, Antibiotics and Implant Retention (DAIR) and soft tissue coverage, the majority of these cases are chronic and in our unit are managed by Debridement, Explantation, Antibiotics (spacer and systemic) and Flap (DEAF).

We report our experience of managing 17 of these challenging cases, 16 DEAFs and one DAIR and flap. Outcomes were assessed clinically and using the 36-item Short Form Health Survey (SF-36).

The mean time from arthroplasty to presentation in our unit was 19months (range: 0.5-80). Whilst an open knee replacement is by definition 'infected', significant microbiological growth from deep tissue/fluid samples was only detected in 14 patients (82%). Five patients (29.4%) subsequently underwent an amputation. Of these five, three patients were extensor deficient at presentation. At follow-up, health-related quality of life scoring using the Short Form-36 demonstrated poor physical function and highlighted differences in emotional function and pain levels between patients whose limbs were salvaged and patients who underwent amputation.

An exposed total knee prosthesis is a devastating complication, which despite our multidisciplinary salvage approach, has a high rate (5/17=29%) of amputation in this series. Quality of life in this patient group is poor irrespective of limb salvage. Salvage surgery was associated with worse pain, but better emotional profile than patients with an above knee amputation.