Purpose: 2–5 years results in the treatment of deep infection of total knee arthroplasty (TKA) after two-stage reimplantation are presented. An articulating antibiotic spacer prosthesis and a standardized antibiotic therapy were used.

Material and Methods: In a prospective study 33 consecutive patients were treated with the articulating spacer, which was made on the table by cleaning and autoclaving removed parts of the infected TKA. A parenteral double antibiotic therapy in combination with rifampin was given for 10 days, followed by oral therapy for 4 weeks.

Results: At a mean follow-up period of 47 months (31 to 67) three patients had reinfection (success rate 91 %). We could increase the average Hospital for Special Surgery knee score from 67 points (44 to 84) to 87 points (53 to 97) after reimplantation.

Based on these results, 25 knees (76 %) were rated excellent, 5 knees (15 %) were rated good, 2 knees (6 %) were rated fair and one patient (3 %) had a poor result. Complications were one temporary peroneal palsy, one luxation of the spacer due to insufficient extensor mechanism and one fracture of the tibia due to substantial primary metaphyseal bone loss.

Conclusion: Using articulating spacer prosthesis disadvantages of joint fixation between the two stages could be reduced. There is no difference in the reinfection rate compared to procedures using fixed spacer blocks. It facilitates the reimplantation and gives good functionel results.

Aims: In this prospective study, we determined whether corrective surgery for rotational malalignment of femoral prosthesis components would benefit patients that had previously undergone total knee arthroplasty.

Methods: 68 consecutive patients with a painful total knee arthroplasty were screened with computed tomography. All patients were offered plain radiographs, tangential radiographs and stress radiography for valgus/varus stability in 20° and 90° flexion. No patient had signs of infection or loosening. 14 patients were selected that had isolated internal malrotation of the femoral component. No other malpositions could be found. Two patients with mild (≤3°) internal mal-rotation were excluded due to conservative treatment. Revision surgery was performed to replace prosthetic components in 12 patients with internal malrotation ≥ 4° within 3 years of the primary arthroplasty

Results: The corrective surgery resulted in an increase in the average Knee Society Score from 51/65 to 86/86 points and an improvement in the average Hospital for Special Surgery knee score from 64 to 83 points. The mean follow-up was 57 (range 46 to 89) months.

Conclusion: This study showed that correction of isolated internal malrotation of the femoral component will lead to better clinical and functional outcomes.

Purpose: There is a growing demand on revision surgery in the last decade. 60 – 80% of these revisions are performed for early failure within the first three years. We are a referral center for painful and failed TKAs and have performed more then 400 revision surgeries between 2000 and 2005. In this paper we have analysed the cause(s) of failure(s) in patients with painful or failed TKAs.

Material and Methods: 100 consecutive revision surgeries were analysed using a standardized diagnostic algorithm. This included extended history, clinical evaluation with special tests and laboratory examinations. Radiographic analysis included standard x-rays, full leg standing weight bearing x-rays and special fluoroscopic views. Patients with suspicion of implant malrotation received a special computer tomography and stress x-rays. In patients with suspicion of infection aspiration of the joint and if negative a dynamic technetium and leucocyte bone scan was performed. The suspected cause(s) of failure(s) was analysed during revision surgery in all cases.

Results: In 48% malalignment (> 4°) caused overloading, pain and/or PE-wear. In 26% malrotation (> 3°) of the tibia and/or femoral component caused either patella malttracking, stiffness or flexion gap instability. In 23% pain was caused by instability either in extension, midflexion and/or full flexion. In 19% the cause of pain was infection. In 24 % several other rare causes could be identified. Only in 9% there was aseptic loosing over the time without any implantation failure. 78% of all revisions were performed within 3 years after the primary surgery.

Conclusions: Aseptic loosing, PE-wear and instability had been described as the main failure mechanisms in TKA. In this study it could be shown, that these are only secondary phenomena’s for the three main implantation failures of malalignment, malrotation and mismatch of the flexion/extension gaps. In most of the early failures within 3 years after primary implantation these revision surgeries might be prevented by a more precise primary implantation.