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The Infected Total Knee
The Journal of Arthroplasty Vol. 20 No. 4 Suppl. 2 2005
The Infected Total Knee Management Options John M. Cuckler, MD
Abstract: The management of infection after total knee arthroplasty depends on the chronicity of the infection, host factors, and sensitivity of the infecting bacteria. Twostage salvage consisting of removal of implants and cement, placement of an antibiotic spacer, and appropriate intravenous antibiotic therapy followed by reimplantation with an antibiotic-impregnated cement appears to be the predominant approach to managing this complication. The use of articulated spacers consisting of the sterilized femoral and polyethylene components with antibiotic cement allows maintenance of motion and bone stock. This report details the author’s experience with 44 infected knee arthroplasties. Key words: knee prosthesis, infection, treatment, antibiotic cement, results. n 2005 Elsevier Inc. All rights reserved.
reported; however, most reports appear to favor a 2-stage approach to the infected knee arthroplasty [2-9]. The 2-stage revision approach uses an antibiotic-impregnated spacer after a thorough debridement of the knee joint. In general, intravenous antibiotics appropriate to the infecting organism are administered for 6 weeks, followed by a second stage implantation of a permanent prosthesis using antibiotic-impregnated bone cement. The antibiotic spacer block has been reported to produce successful results in control of the infection [10]. However, use of the spacer block technique is accompanied by stiffness of the knee joint and may be associated with compromise of bone stock [11]. This requires more aggressive surgical exposure at the second stage reimplantation, using techniques such as a quadriceps snip or even turn down. In addition, an inevitable degree of osteopenia results from disuse of the extremity. An articulated spacer technique using the sterilized femoral and tibial polyethylene components, coated with antibiotic-containing bone cement or antibiotic bone cement alone (prosthesis of antibiotic-loaded acrylic cement [PROSTALAC]), allows both weight bearing and motion of the joint during the period of antibiotic therapy [12,13]. Exposure of the joint is straightforward at the time of
Infection after total knee arthroplasty presents the surgeon with one of the more challenging and disappointing experiences in joint arthroplasty. Careful evaluation of the chronicity of the process, host factors, and bacteriology are necessary to optimize the outcome. This review will describe an algorithm for the management of this complication. The management options for the infected knee include both 1-stage and 2-stage revision techniques. In the setting of acute infection (ie, b10 days from the onset of symptoms), primary debridement has been reported as successful in 56% of patients with low-grade organisms such as Staphylococcus epidermidis or streptococcal species infections, but only 8% in the presence of Staphylococcus aureus infections [1]. Satisfactory results with single-stage revision of the infected total knee arthroplasty in the presence of low-grade organisms have been
From the Division of Orthopaedic Surgery, University of Alabama at Birmingham, Birmingham, AL. No benefits or funds were received in support of the study. Reprint requests: John M. Cuckler, MD, Division of Orthopaedic Surgery University of Alabama at Birmingham, FOT 930, 1530 3rd Ave. S. Birmingham, AL 35294-3409. n 2005 Elsevier Inc. All rights reserved. 0883-5403/04/2004-2011$30.00/0 doi:10.1016/j.arth.2005.03.004
33
34 The Journal of Arthroplasty Vol. 20 No. 4 Suppl. 2 June 2005 Erythrocyte sedimentation rates (ESRs) and a C-reactive protein (CRP) level are obtained at weeks 6 and 12.
Materials and Methods
Fig. 1. (A) Anteroposterior view of articulated spacer with antibiotic cement. This patient waited 2 years after the initial debridement before undergoing second stage reimplantation, with excellent function of the spacer. (B) Lateral view of the same patient (A). Note that the patella has not been resurfaced. When the medullary canal of the tibia or femur has been violated, a column of antibiotic cement should be inserted in the canal for local antibiotic delivery.
revision, as most patients obtain near-normal motion of the temporary knee prosthesis. The technique for the articulated antibiotic spacer is simple and straightforward. At the time of the debridement, the femoral and tibial components are removed. If the tibial component is modular, the metal tray should be dissociated from the polyethylene. After cleansing the femoral component of any retained bone cement, the femoral component and tibial polyethylene are placed in the autoclave for 10 minutes and then returned to the operative field in sterile condition. After thorough debridement of the joint, including removal of all retained bone cement, and copious irrigation of the joint with 6 L of antibiotic irrigant solution, the sterile femoral component and tibial polyethylene are coated with antibiotic-containing bone cement. The cement is allowed to polymerize into a highly viscous state and then used as a grout between the exposed bone surfaces and the recycled components. The knee is held in extension, in anatomic alignment. Excess cement is molded around the edges of the components to increase the surface area exposure of the antibiotic cement to the knee joint. The patella is not resurfaced (Fig. 1A and B). Intravenous antibiotics specific to the organism are generally used for 6 weeks. A complete blood cell count and renal function studies are performed weekly to monitor the antibiotic therapy.
Forty-four chronic (ie, duration of infection N1 month) total knee infections were treated with an articulated antibiotic-loaded spacer between 1994 and 2002. The average age of the group was 68 years (range, 44-92 years), 31 of whom were women. The patients were classified according to the method of McPherson et al [14] to characterize their host status. All patients underwent preoperative evaluation including Knee Society Score, ESR, CRP level, and aspiration of the joint [15]. The sterilized femoral component and tibial polyethylene were coated with bone cement containing 4.8 g of tobramycin in each 40 g of bone cement. A 2-tailed Student t test was applied to the comparison of motion before and after second stage conversion surgery, with P = .05 considered significant.
Results Staphylococcus epidermidis comprised 50% of the infecting organisms, as shown in Table 1. Six patients had multiple negative cultures; all had prior antibiotic therapy and demonstrated an elevated ESR and CRP level preoperatively. According to the classification of McPherson et al [14], 14 patients were classified bAQ hosts, 20 were classified as bBQ hosts, and the remainder were classified as type bCQ hosts. All patients received intravenous antibiotics specific to the identified organism for 6 weeks; for the 6 patients with negative cultures, vancomycin was empirically selected as the intravenous antibiotic. Peak and trough levels were obtained weekly, as were a complete blood cell count and serum urea nitrogen and creatinine levels. The ESR and CRP level were
Table 1. Culture Results Among 44 Infected Total Knee Arthroplasties Organism S epidermidis Methicillin-sensitive S aureus Methicillin-resistant S aureus Klebsiella species Mixed organisms Negative cultures
No. of Patients 22 6 5 1 4 6
The Infected Total Knee Arthroplasty ! John M. Cuckler
obtained at weeks 6 and 12; patients underwent second stage conversion between 18 weeks and 2 years after first stage debridement. The patients were allowed weight bearing and motion as tolerated of the joint during this period of treatment and observation. Ninety-five percent of the patients were full weight bearing, without assistive devices, by postoperative week 8. The average range of motion of the articulated spacer was 1108 (range, 458-1258) at 12 weeks after debridement. Four patients were so comfortable with the articulated spacer that they delayed a second stage conversion more than 1 year. The average Knee Society Score before debridement was 36 (range, 7-48); at 1 year after reimplantation, the average Knee Society Score was 84 (range, 45-98). Range of motion at 1 year after second stage reimplantation averaged 1128 (range, 458-1258). There was no statistically significant difference between motion after placement of the articulated spacer and range of motion after revision ( P = .8). No patient required a quadriceps snip or other similar procedure to enhance exposure at the time of second stage reimplantation. A lateral release was performed in 82% of the patients at the time of initial implant removal and debridement; 1 patient had a quadriceps snip performed at the time of implant removal because of extremely limited flexion preoperatively. There has been only 1 failure in this series, which presented with recurrent infection with the same organism at about 6 months after placement of the articulated spacer, before second stage reimplantation. This patient had failed prior incomplete surgical therapy at another hospital and presented initially with a 14-month history of active infection with a methicillin-sensitive S aureus. The patient had multiple medical comorbidities that compromised his host defense. At an average of 5.4 years of follow-up (range, 2-10 years), there have been no recurrence of infection. All patients had at least 1.2 g of tobramycin added to each 40 g of cement. None of the patients who underwent a second stage conversion required a quadriceps snip or turn down. The average range of motion after second stage conversion was 1208 (range, 608-1308) at 1 year after surgery.
Discussion Hofman et al [12] have described their experience with 26 patients using this technique. He
35
reports no recurrences of infection, with excellent range of motion after second stage conversion [12]. Haddad et al [13] have reported 91% success with the PROSTALAC spacer. However, the PROSTALAC device is not as durable as the recycled knee components and can produce mechanical complications such as fracture of the spacer if second stage conversion is delayed. In addition, there are extra costs associated with the molds and extraoperative time in preparation of the PROSTALAC components. The advantage of maintenance of motion and bone stock quality during the period between the first and second stage of the salvage of the infected knee is a compelling advantage compared with a static cement spacer block. In conclusion, 2-stage management appears to produce the best outcome for the infected total knee arthroplasty. This requires a thorough debridement of the joint, with removal of all implants and all retained bone cement. Intravenous antibiotics administered for 6 weeks appear to produce the most reliable results. The use of articulated spacer is an effective and easy way of maintaining motion and bone stock quality, without compromising the outcome of the antibiotic treatment.
References 1. Deirmengian C, Greenbaum J, Stern J, et al. Open debridement of acute gram-positive infections after total knee arthroplasty. Clin Orthop 2003;416:129. 2. Silva M, Tharani R, Schmalzried TP. Results of direct exchange or debridement of the infected total knee arthroplasty. Clin Orthop 2002;404:125. 3. Buechel FF, Femino FP, D’Alessio J. Primary exchange revision arthroplasty for infected total knee replacement: a long-term study. Am J Orthop 2004; 4:190. 4. Nazarian DG, de Jesus D, McGuigan F, et al. A two-stage approach to primary knee arthroplasty in the infected arthritic knee. J Arthroplasty 2003; 18(Suppl 1):16. 5. Goldman RT, Scuderi GR, Insall JN. 2-stage reimplantation for infected total knee replacement. Clin Orthop 1996;331:118. 6. Hirakawa K, Stulberg BN, Wilde AH, et al. Results of 2-stage reimplantation for infected total knee arthroplasty. J Arthroplasty 1998;13:22. 7. Segawa H, Tsukayama DT, Kyle RF, et al. Infection after total knee arthroplasty. A retrospective study of the treatment of eighty-one infections. J Bone Joint Surg Am 1999;81:1434. 8. Tsukayama DT, Goldberg VM, Kyle R. Diagnosis and management of infection after total knee arthroplasty. J Bone Joint Surg Am 2003;85(Suppl 1):S75.
36 The Journal of Arthroplasty Vol. 20 No. 4 Suppl. 2 June 2005 9. Insall JN, Thompson F, Brause BD. Two-stage reimplantation for the salvage of infected total knee arthroplasty. J Bone Joint Surg Am 1983;65-A:1087. 10. Booth RE, Lotke PA. The results of spacer block technique in revision of infected total knee arthroplasty. Clin Orthop 1989;248:13. 11. Fehring TK, Odum S, Calton TF, et al. Articulating versus static spacers in revision total knee arthroplasty for sepsis. Clin Orthop 2000;380:9. 12. Hofmann AA, Kane KR, Tkach TK, et al. Treatment of infected total knee arthroplasty using an articulating spacer. Clin Orthop 1995;321:45.
13. Haddad FS, Masri BA, Campbell D, et al. The PROSTALAC functional spacer in two-stage revision for infected knee replacements. Prosthesis of antibiotic-loaded acrylic cement. J Bone Joint Surg Br 2000;82B:807. 14. McPherson EJ, Tontz Jr W, Patzakis M, et al. Outcome of infected total knee utilizing a staging system for prosthetic joint infection. Am J Orthop 1999;28:161. 15. Insall JN, Dorr LD, Scott RD, et al. Rationale of the Knee Society clinical rating system. Clin Orthop 1989;248:13.
The Infected Total Knee Management Options John M. Cuckler, MD
Abstract: The management of infection after total knee arthroplasty depends on the chronicity of the infection, host factors, and sensitivity of the infecting bacteria. Twostage salvage consisting of removal of implants and cement, placement of an antibiotic spacer, and appropriate intravenous antibiotic therapy followed by reimplantation with an antibiotic-impregnated cement appears to be the predominant approach to managing this complication. The use of articulated spacers consisting of the sterilized femoral and polyethylene components with antibiotic cement allows maintenance of motion and bone stock. This report details the author’s experience with 44 infected knee arthroplasties. Key words: knee prosthesis, infection, treatment, antibiotic cement, results. n 2005 Elsevier Inc. All rights reserved.
reported; however, most reports appear to favor a 2-stage approach to the infected knee arthroplasty [2-9]. The 2-stage revision approach uses an antibiotic-impregnated spacer after a thorough debridement of the knee joint. In general, intravenous antibiotics appropriate to the infecting organism are administered for 6 weeks, followed by a second stage implantation of a permanent prosthesis using antibiotic-impregnated bone cement. The antibiotic spacer block has been reported to produce successful results in control of the infection [10]. However, use of the spacer block technique is accompanied by stiffness of the knee joint and may be associated with compromise of bone stock [11]. This requires more aggressive surgical exposure at the second stage reimplantation, using techniques such as a quadriceps snip or even turn down. In addition, an inevitable degree of osteopenia results from disuse of the extremity. An articulated spacer technique using the sterilized femoral and tibial polyethylene components, coated with antibiotic-containing bone cement or antibiotic bone cement alone (prosthesis of antibiotic-loaded acrylic cement [PROSTALAC]), allows both weight bearing and motion of the joint during the period of antibiotic therapy [12,13]. Exposure of the joint is straightforward at the time of
Infection after total knee arthroplasty presents the surgeon with one of the more challenging and disappointing experiences in joint arthroplasty. Careful evaluation of the chronicity of the process, host factors, and bacteriology are necessary to optimize the outcome. This review will describe an algorithm for the management of this complication. The management options for the infected knee include both 1-stage and 2-stage revision techniques. In the setting of acute infection (ie, b10 days from the onset of symptoms), primary debridement has been reported as successful in 56% of patients with low-grade organisms such as Staphylococcus epidermidis or streptococcal species infections, but only 8% in the presence of Staphylococcus aureus infections [1]. Satisfactory results with single-stage revision of the infected total knee arthroplasty in the presence of low-grade organisms have been
From the Division of Orthopaedic Surgery, University of Alabama at Birmingham, Birmingham, AL. No benefits or funds were received in support of the study. Reprint requests: John M. Cuckler, MD, Division of Orthopaedic Surgery University of Alabama at Birmingham, FOT 930, 1530 3rd Ave. S. Birmingham, AL 35294-3409. n 2005 Elsevier Inc. All rights reserved. 0883-5403/04/2004-2011$30.00/0 doi:10.1016/j.arth.2005.03.004
33
34 The Journal of Arthroplasty Vol. 20 No. 4 Suppl. 2 June 2005 Erythrocyte sedimentation rates (ESRs) and a C-reactive protein (CRP) level are obtained at weeks 6 and 12.
Materials and Methods
Fig. 1. (A) Anteroposterior view of articulated spacer with antibiotic cement. This patient waited 2 years after the initial debridement before undergoing second stage reimplantation, with excellent function of the spacer. (B) Lateral view of the same patient (A). Note that the patella has not been resurfaced. When the medullary canal of the tibia or femur has been violated, a column of antibiotic cement should be inserted in the canal for local antibiotic delivery.
revision, as most patients obtain near-normal motion of the temporary knee prosthesis. The technique for the articulated antibiotic spacer is simple and straightforward. At the time of the debridement, the femoral and tibial components are removed. If the tibial component is modular, the metal tray should be dissociated from the polyethylene. After cleansing the femoral component of any retained bone cement, the femoral component and tibial polyethylene are placed in the autoclave for 10 minutes and then returned to the operative field in sterile condition. After thorough debridement of the joint, including removal of all retained bone cement, and copious irrigation of the joint with 6 L of antibiotic irrigant solution, the sterile femoral component and tibial polyethylene are coated with antibiotic-containing bone cement. The cement is allowed to polymerize into a highly viscous state and then used as a grout between the exposed bone surfaces and the recycled components. The knee is held in extension, in anatomic alignment. Excess cement is molded around the edges of the components to increase the surface area exposure of the antibiotic cement to the knee joint. The patella is not resurfaced (Fig. 1A and B). Intravenous antibiotics specific to the organism are generally used for 6 weeks. A complete blood cell count and renal function studies are performed weekly to monitor the antibiotic therapy.
Forty-four chronic (ie, duration of infection N1 month) total knee infections were treated with an articulated antibiotic-loaded spacer between 1994 and 2002. The average age of the group was 68 years (range, 44-92 years), 31 of whom were women. The patients were classified according to the method of McPherson et al [14] to characterize their host status. All patients underwent preoperative evaluation including Knee Society Score, ESR, CRP level, and aspiration of the joint [15]. The sterilized femoral component and tibial polyethylene were coated with bone cement containing 4.8 g of tobramycin in each 40 g of bone cement. A 2-tailed Student t test was applied to the comparison of motion before and after second stage conversion surgery, with P = .05 considered significant.
Results Staphylococcus epidermidis comprised 50% of the infecting organisms, as shown in Table 1. Six patients had multiple negative cultures; all had prior antibiotic therapy and demonstrated an elevated ESR and CRP level preoperatively. According to the classification of McPherson et al [14], 14 patients were classified bAQ hosts, 20 were classified as bBQ hosts, and the remainder were classified as type bCQ hosts. All patients received intravenous antibiotics specific to the identified organism for 6 weeks; for the 6 patients with negative cultures, vancomycin was empirically selected as the intravenous antibiotic. Peak and trough levels were obtained weekly, as were a complete blood cell count and serum urea nitrogen and creatinine levels. The ESR and CRP level were
Table 1. Culture Results Among 44 Infected Total Knee Arthroplasties Organism S epidermidis Methicillin-sensitive S aureus Methicillin-resistant S aureus Klebsiella species Mixed organisms Negative cultures
No. of Patients 22 6 5 1 4 6
The Infected Total Knee Arthroplasty ! John M. Cuckler
obtained at weeks 6 and 12; patients underwent second stage conversion between 18 weeks and 2 years after first stage debridement. The patients were allowed weight bearing and motion as tolerated of the joint during this period of treatment and observation. Ninety-five percent of the patients were full weight bearing, without assistive devices, by postoperative week 8. The average range of motion of the articulated spacer was 1108 (range, 458-1258) at 12 weeks after debridement. Four patients were so comfortable with the articulated spacer that they delayed a second stage conversion more than 1 year. The average Knee Society Score before debridement was 36 (range, 7-48); at 1 year after reimplantation, the average Knee Society Score was 84 (range, 45-98). Range of motion at 1 year after second stage reimplantation averaged 1128 (range, 458-1258). There was no statistically significant difference between motion after placement of the articulated spacer and range of motion after revision ( P = .8). No patient required a quadriceps snip or other similar procedure to enhance exposure at the time of second stage reimplantation. A lateral release was performed in 82% of the patients at the time of initial implant removal and debridement; 1 patient had a quadriceps snip performed at the time of implant removal because of extremely limited flexion preoperatively. There has been only 1 failure in this series, which presented with recurrent infection with the same organism at about 6 months after placement of the articulated spacer, before second stage reimplantation. This patient had failed prior incomplete surgical therapy at another hospital and presented initially with a 14-month history of active infection with a methicillin-sensitive S aureus. The patient had multiple medical comorbidities that compromised his host defense. At an average of 5.4 years of follow-up (range, 2-10 years), there have been no recurrence of infection. All patients had at least 1.2 g of tobramycin added to each 40 g of cement. None of the patients who underwent a second stage conversion required a quadriceps snip or turn down. The average range of motion after second stage conversion was 1208 (range, 608-1308) at 1 year after surgery.
Discussion Hofman et al [12] have described their experience with 26 patients using this technique. He
35
reports no recurrences of infection, with excellent range of motion after second stage conversion [12]. Haddad et al [13] have reported 91% success with the PROSTALAC spacer. However, the PROSTALAC device is not as durable as the recycled knee components and can produce mechanical complications such as fracture of the spacer if second stage conversion is delayed. In addition, there are extra costs associated with the molds and extraoperative time in preparation of the PROSTALAC components. The advantage of maintenance of motion and bone stock quality during the period between the first and second stage of the salvage of the infected knee is a compelling advantage compared with a static cement spacer block. In conclusion, 2-stage management appears to produce the best outcome for the infected total knee arthroplasty. This requires a thorough debridement of the joint, with removal of all implants and all retained bone cement. Intravenous antibiotics administered for 6 weeks appear to produce the most reliable results. The use of articulated spacer is an effective and easy way of maintaining motion and bone stock quality, without compromising the outcome of the antibiotic treatment.
References 1. Deirmengian C, Greenbaum J, Stern J, et al. Open debridement of acute gram-positive infections after total knee arthroplasty. Clin Orthop 2003;416:129. 2. Silva M, Tharani R, Schmalzried TP. Results of direct exchange or debridement of the infected total knee arthroplasty. Clin Orthop 2002;404:125. 3. Buechel FF, Femino FP, D’Alessio J. Primary exchange revision arthroplasty for infected total knee replacement: a long-term study. Am J Orthop 2004; 4:190. 4. Nazarian DG, de Jesus D, McGuigan F, et al. A two-stage approach to primary knee arthroplasty in the infected arthritic knee. J Arthroplasty 2003; 18(Suppl 1):16. 5. Goldman RT, Scuderi GR, Insall JN. 2-stage reimplantation for infected total knee replacement. Clin Orthop 1996;331:118. 6. Hirakawa K, Stulberg BN, Wilde AH, et al. Results of 2-stage reimplantation for infected total knee arthroplasty. J Arthroplasty 1998;13:22. 7. Segawa H, Tsukayama DT, Kyle RF, et al. Infection after total knee arthroplasty. A retrospective study of the treatment of eighty-one infections. J Bone Joint Surg Am 1999;81:1434. 8. Tsukayama DT, Goldberg VM, Kyle R. Diagnosis and management of infection after total knee arthroplasty. J Bone Joint Surg Am 2003;85(Suppl 1):S75.
36 The Journal of Arthroplasty Vol. 20 No. 4 Suppl. 2 June 2005 9. Insall JN, Thompson F, Brause BD. Two-stage reimplantation for the salvage of infected total knee arthroplasty. J Bone Joint Surg Am 1983;65-A:1087. 10. Booth RE, Lotke PA. The results of spacer block technique in revision of infected total knee arthroplasty. Clin Orthop 1989;248:13. 11. Fehring TK, Odum S, Calton TF, et al. Articulating versus static spacers in revision total knee arthroplasty for sepsis. Clin Orthop 2000;380:9. 12. Hofmann AA, Kane KR, Tkach TK, et al. Treatment of infected total knee arthroplasty using an articulating spacer. Clin Orthop 1995;321:45.
13. Haddad FS, Masri BA, Campbell D, et al. The PROSTALAC functional spacer in two-stage revision for infected knee replacements. Prosthesis of antibiotic-loaded acrylic cement. J Bone Joint Surg Br 2000;82B:807. 14. McPherson EJ, Tontz Jr W, Patzakis M, et al. Outcome of infected total knee utilizing a staging system for prosthetic joint infection. Am J Orthop 1999;28:161. 15. Insall JN, Dorr LD, Scott RD, et al. Rationale of the Knee Society clinical rating system. Clin Orthop 1989;248:13.