THE MANAGEMENT OF FAILED ANKLE REPLACEMENTS

Abstract

The resurgency of ankle replacement in the last 10 years has prompted a need for effective management of failing prostheses. We present the early to mid-term results for revision surgery of 17 arthroplasties in 17 patients from our tertiary referral centre.

Between 1999 and 2004, two Consultant Foot and Ankle Surgeons revised failing ankle arthroplasties in 17 patients (age range 51–74 years). All patients were assessed with tissue cultures and histology that were harvested at the time of surgery and managed in conjunction with a specialist Bone Infection Unit.

Intraoperative frozen section was used to aid management, but usually pre-operative decisions had been made which included

• one or two stage reimplantation

• fusion with an intramedullary nail or Ilizarov frame

• amputation, and

• Ilizarov fusion combined with proximal tibial lengthening for excessive bone loss.

Many of the patients had had previous “revision surgery” such as change of meniscal components, arthroscopic debridements and excision of impingeing osteophytes.

Indications for implantation had been osteoarthritis in 59%, rheumatoid arthritis in 18% and post-trauma in 23%. Heel shift procedures to correct malalignment had been performed in 12%.

The implants comprised 15 Scandinavian Total Ankle Replacements (STAR), one Agility and one Buechel-Pappas. Three patients had fractured malleoli secondary to bone loss.

Cultures and histology confirmed the presence of infection in 24% (defined as positive histology and more than 2/6 positive cultures) with aseptic loosening in the remainder.

One infected patient underwent amputation at his request. Six non-infected patients had successful revision of two or three components, one infected patient had Ilizarov fusion and lengthening. The remainder underwent successful hindfoot fusion over a locked intramedullary nail, even in the presence of infection, with suppression to union.