Advance medial pivot total knee replacement has been designed to reflect contemporary data regarding knee kinematics. We report the clinical outcome of 284 replacements in 225 consecutive patients. All patients were prospectively followed for a mean of 7.6 years (5 to 9) using validated rating systems, both objective and subjective.

All patients showed a statistically significant improvement (p~0.01) on the Knee Society clinical rating system, WOMAC questionnaire, SF-12 questionnaire, and Oxford knee score. The majority of patients (92%) were able to perform age appropriate activities with a mean knee flexion of 117° (85 to 135). Survival analysis showed a cumulative success rate of 99.1% (95% CI, 86.6 to 100) at five years and 97.5% (95% CI, 65.6 to 100) at seven years. Two (0.7%) replacements were revised due to aseptic loosening, one (0.35%) due to infection and one (0.35%) due to a traumatic dislocation. In only two (0.7%) replacements, progressive radiological lucent lines (combined with beta angle of 85°) were observed

Two-staged revision TKA is a common strategy for the management of infected TKA (i-TKA) in properly selected patients. However, there is considerable variation in the parameters (e.g. the duration of intravenous administration of antibiotics and of the time interval between the stages, the intraoperative use of frozen sections, the use of knee aspiration etc.) of the treatment protocol among Orthopaedic Centres making the comparative evaluation of results difficult. The aim of this study is to present a standardised two-staged revision protocol with satisfactory mid-term clinical outcome.

Thirty-four consecutive cases of infected primary TKAs were treated in our department between 2000 and 2006. For 24 of them the postoperative follow-up is greater than 2 years. All patients underwent the same treatment protocol: knee aspiration prior to implant removal and surgical debridement, more than 5 specimens for frozen sections and cultures (aerobic, anaerobic and fungi) during the first stage, custom antibiodic impregnated cement spacers, intravenous administration of antibiotics for 3 weeks followed by 3 weeks of per os administration based on culture and antibiogram, a 6-week interval free from antibiotics, second aspiration and second stage with repetition of frozen sections and cultures. In the case of positive frozen section specimens during the second stage the implantation of a new prosthesis was cancelled and a different management strategy was introduced. Preoperative and postoperative data were collected in the form of Total Knee Society Score (knee score and functional score), Oxford-12 Score, laboratory parameters and radiographs at regular intervals.

At the final follow-up 22 out of 24 patients were free of infection. In four patients (2 Host C and 1 Host B) the 2nd stage was repeated (2–6 times) due to polymicrobial infection and positive intraoperative frozen sections. In one of them a knee arthrodesis was finally performed. The diagnostic accuracy of knee aspiration before the 1st stage was low. Total Knee Society Score rose from a preoperative average of 64 (50 to 95) to a postoperative average of 145 (130 to 180). The Oxford 12 score also rose from a preoperative average of 52 (44 to 58) to a postoperative average of 30 (23 to 38). At the final follow-up no radiological signs of implant loosening were observed.

The above standardised protocol of two-staged revision in i-TKA, when indicated, can provide satisfactory mid-term clinical results.

Deep infection following total knee arthroplasty (TKA) is a devastating complication for the patient and a costly one for patients, surgeons, hospitals and payers. The aim of this study is to compare revision TKA for infection, revision TKA for aseptic loosening and primary TKA with respect to their impact on hospital and surgeon resource utilisation. The evaluation of hospital cost was carried out on a microeconomic basis in order to best evaluate the true cost.

Demographic, clinical and economic data were obtained for 25 consecutive patients with an infection after TKA who underwent a two-stage revision arthroplasty (Group 1), 25 consecutive patients who underwent revision of both components because of aseptic loosening (Group 2) and 25 consecutive patients who underwent a primary TKA (Group 3), all of which where admitted at our institution between January 2000 and December 2005. The economic evaluation included both surgical treatment and hospitalisation cost. Because fixed charges do not depict accurately real resource consumption, total cost was calculated through direct cost analysis. All direct health sector costs such as medical supplies, drugs, implants, laboratory and radiology tests, salaries and wages and overhead expenses, including equipment and plant depreciation were calculated. All patients were followed up for a twelve-month period.

Revision procedures for infection were associated with longer operative time, more blood loss and a higher total number of operations compared with both revisions for aseptic loosening and primary TKA. Furthermore, revisions for infection compared to revisions due to aseptic loosening and primary TKAs were associated with twofold and 2.6 times higher total number of hospitalisations, 2.5 and 5.6 times higher total number of inpatient days, 10.2 and 53.8 times higher cost of inpatient drugs and 1.2 and 2.37 times higher cost of implants, respectively. The costing evaluation of the three operative techniques is still on progress.

Patients’ treatment with an infection after TKA is associated with significantly greater hospital and physician resource utilisation compared with that used for patients with a revision due to aseptic loosening or a primary TKA.