Use of a New Knee Prosthesis as an Articulating Spacer in Two-Stage Revision of Infected Total Knee Arthroplasty

PURPOSE: To report our experience with two-stage revision using a new femoral component (NFC) spacer (Depuy Synthes) as an articulating spacer. MATERIALS AND METHODS: In this retrospective study, we reviewed 22 two-stage revisions that were performed using an NFC spacer in 22 patients suspected of having an infected total knee arthroplasty (TKA) from December 2010 to March 2013. The result was considered successful when eradication of infection was achieved using only one NFC spacer. RESULTS: The average time from primary TKA to the first stage procedure was 29.1 months and the average time from the first stage procedure until the final second stage procedure was 12.7 weeks. The average range of motion increased from 82° preoperatively to 104° postoperatively. The American Knee Society Knee score increased from 29.3 points to 66 points. The Function score increased from 29.5 points to 64 points. Four cases were reinfected after two-stage revision. The mean follow-up was 37.6 months. CONCLUSIONS: The new articulating spacer showed promising short-term results both with regard to eradication of infection and functional improvement.

Two-Stage Revision for Infected Total Knee Arthroplasty: Based on Autoclaving the Recycled Femoral Component and Intraoperative Molding Using Antibiotic-Impregnated Cement on the Tibial Side

BACKGROUND: The purpose of this study was to determine the degree of infection control and postoperative function for new articulating metal-on-cement spacer. METHODS: A retrospective study of 19 patients (20 cases), who underwent a two-stage revision arthroplasty using mobile cement prosthesis, were followed for a minimum of 2 years. This series consisted of 16 women and 3 men, having an overall mean age of 71 years. During the first stage of revision, the femoral implant and all the adherent cement was removed, after which it was autoclaved before replacement. The tibial component was removed and a doughy state, antibiotic-impregnated cement was inserted on the tibial side. To achieve joint congruency, intraoperative molding was performed by flexing and extending the knee joint. Each patient was evaluated clinically and radiologically. The clinical assessments included range of motion, and the patients were scored as per the Hospital for Special Surgery (HSS) and Knee Society (KS) criteria. RESULTS: The mean range of knee joint motion was 70degrees prior to the first stage operation and 72degrees prior to the second stage revision arthroplasty; following revision arthroplasty, it was 113degrees at the final follow-up. The mean HSS score and KS knee and function scores were 86, 82, and 54, respectively, at the final follow-up. The success rate in terms of infection eradication was 95% (19/20 knees). No patient experienced soft tissue contracture requiring a quadriceps snip. CONCLUSIONS: This novel technique provides excellent radiological and clinical outcomes. It offers a high surface area of antibiotic-impregnated cement, a good range of motion between first and second stage revision surgery for the treatment of chronic infection after total knee arthroplasty, and is of a reasonable cost.

Two-Stage Reimplantation in Infected Total Knee Arthroplasty (A Method of Reinsertion of the Autoclaved Femoral Component and a Polyethylene Liner)

PURPOSE: We wanted to evaluate the results of treating infected total knee arthroplasty with an autoclaved femoral component and polyethylene liner. MATERIALS AND METHODS: From March 2003 to March 2008, 25 knees were diagnosed as infected total knee arthroplasty (TKA) and they underwent two-stage re-implantation. These knees were treated with debridement, reinsertion of the removed femoral component and a polyethylene liner, which were autoclaved, and antibiotic cement was used as an articulating spacer during the interim period to allow maintenance of motion and function. The range of motion and the Hospital for Special Surgery (HSS) score, the Knee Society Knee Score and the Function Score were evaluated. RESULTS: The mean follow up period was 52 months. There was one recurrence of infection. Prior to revision, the average range of motion was 83degrees and the average HSS score was 60 points. At final follow-up, the average range of motion was 110degrees and the average HSS score was 86 points. The knee score and function score showed an increase from a mean of 46 and 31 points preoperatively to a mean of 82 and 50 points postoperatively. The complications during reimplantation were one medial collateral ligament rupture, one lateral condyle fracture and one femoral distal metaphyseal fracture. CONCLUSION: The articulating spacer using an autoclaved femoral component and polyethylene can improve knee function and motion in two stage revision TKA.

An Articulating Versus Non-articulating Spacer for 2-Stage Reimplantation Patients Who Undergo in Infected Total Knee Arthroplasty

PURPOSE: We compared the results between an articulating spacer and a non-articulating spacer for 2-stage reimplantation when performing infected total knee arthroplasty (TKA). MATERIALS AND METHODS: From 1998 to 2007, for 22 patients with infected TKA, we retrospectively evaluated 23 knees that were treated with debridement, component removal and insertion of a non-articulating or articulating spacer, followed by second-stage TKA revision. Non-articulating spacers were used in 13 knees and articulating spacers were used in 10 knees. The most common infecting organism was Staphylococcus aureus in 9 cases, but the infecting organism could not be found in 10 cases. The average length of follow-up was 24 months. RESULTS: The eradication rate was 100% (0 infections in 10 knee) in the articulating group compared with 92.3% (1 infection in 13 knee) in the non-articulating group. The average range of motion before removal of the implant was 60.3degrees for the articulating group and 61degrees for the non-articulating group. After revision arthroplasty, the average range of motion was 104.3degrees for the articulating group and 92.3degrees for the non-articulating group. The rectus snip was done for 3 cases in the articulating group and in 13 cases for the non-articulating group. Yet there were no functional differences between the two groups during the final follow-up period. CONCLUSION: We conclude that the articulating spacer can maintain knee mobility during between the interval stages and improve knee flexion without an increased risk of infection at the final follow-up period.

Comparison of Articular Spacer Versus Static Spacer in the Treatment of Infected Total Knee Arthroplasty

PURPOSE: To compare and analyze the surgical procedure and clinical results of two-stage re-implantation using both articulating and static spacers at infected total knee arthroplasties(TKA). MATERIALS & METHODS: A total of 14 cases were selected for subject of this study in which patients had been diagnosed as infected TKA and had undergone two-stage re-implantation(7 using static spacers and remaining 7 using articulating spacers) from March 1999 to March 2006. RESULTS: In the group using static spacers, ROM improved from 70 degrees in average preoperatively to 98 degrees postoperatively. In the group using articulating spacers, ROM improved from 74 degrees to 105 degrees (p=0.532). HSS score showed an increase from 43 scores in average preoperatively to 81 postoperatively for static spacers and from 41 to 83 for articulating spacers(p=0.780). There was no significant difference in the hour spent for the 1st surgery. The 2nd operation time was shortened to 241 minutes in case of static spacers, and 208 minutes in articulating spacers. One case of relapse was reported with static spacers but none with articulating spacers. CONCLUSION: Two-stage re-implantation of infected TKA using both static and articulating spacers has been found to be effective ways of treatment, requiring, however, long term follow-ups.

Role of Articulating Spacer in Two Stage Reimplantation of Infected Total Knee Arthroplasty

The objective of this study is to assess the role of articulating spacer in two stage reimplantation of infected TKA. Fifteen patients with deep infected total knee arthroplasties were treated by two stage reimplantation protocol between Jan. 1987 and Oct. 1997. Seven cases in Group A were treated by debridement, removal of the prosthesis and placement of antibiotic impregnated cement spacer before reimplantation. Eight cases in Group B were treated by debridement, and reinsertion of the retrieved implant after autoclaving with antibiotic impregnated cement fixation. The average follow-up period was 77 months(range, 28-141 months) in group A, and 25 months(range, 12-63 months) in group B. The average knee flexion after revision was 82 degrees in group A, and 106 degrees in group B. The average HSS knee rating score was 80 points in group A, and 88 points in group B. No patient had recurrence of infection during the follow-up period. In conclusion, our method using articulating spacer allowed emly range of motion and partial weight bearing during the spacer phase. This methods also delivered high local concentration of antibiotics and kept the functional joint before a second-stage reimplantation.