Data in Brief: Treating Infected Joints

Romano CL, Drago L, Logoluso N.
Musculoskeletal Infection  Society (MSIS). 2013 July 30.

SUMMARY Peri-prosthetic infection is among the most common reason for revision in the United States and in Europe. Two-stage revision with antibiotic-loaded spacers is the gold standard with an eradication rate greater than 90 percent. High antibiotic concentration (greater than 2 percent) and the association of more than one antibiotic in the spacer are proposed by different authors in a limited series of patients.

MATERIALS AND METHODS A systematic review of published papers on two-stage revisions of infected total hip and knee arthroplasties treated with the routine use of an industrial low-dose (1.9 percent) gentamicin-loaded, preformed spacer has been performed. This systematic review evaluated the hypothesis: are high antibiotic concentrations and antibiotic associations necessary for interim spacers in routine two-stage revision surgery? Papers that were included were published in peer-reviewed journals from the years 1995 to 2013 and reported an infection eradication rate of two-stage hip or knee joint prosthesis with the use of an industrial, preformed low-dosegentamicin spacer (Spacer G or Spacer K, Tecres SpA, Italy. InterSpace® Hip or InterSpace Knee, Exactech, Inc. USA). The systematic review excluded case reports, clinical series with less than 10 patients, duplicate studies and mean follow-up less than 24 months.

RESULTS Twenty-four papers were retrieved, 10 of which met the inclusion criteria, yielding a total of 491 spacers implanted in10 centers (seven in Europe, two in North America and one in Oceania). Nineteen patients (3.9 percent) had an infection recurrence/persistence that required a spacer exchange or are section arthroplasty.

Twenty-five of the 480 patients (5.2percent) that underwent the second stage procedure had an infection recurrence/persistence at an average follow-up of 46 months.

KEY QUOTE “This systematic review provides evidence in favor of the routine use of an industrially, preformed spacer loaded with a standardized, relatively low concentration of gentamicin,[and] that in different centers, showed an average infection eradication rate of 96.1 percent at spacer removal and 94.8percent at the latest follow-up after re-implantation. The systematic review does not support the hypothesis that the antibiotic associations or antibiotic concentrations higher than1.9 percent are routinely needed for spacers used in two stage revision surgery.”

Mutimer J, Gillespie G, Lovering AM, Porteous AJ.
Knee. 2009 Jan;16(1):39-41. doi: 10.1016/j.knee.2008.07.009. Epub 2008 Sep 10.

SUMMARY Previous in-vitro studies have found high levels of antibiotic release in the days immediately following implantation of antibiotic-loaded, articulating spacers. However, there is relatively little data describing the elution profile beyond this immediate period. This study was designed to measure if gentamicin levels continue to be clinically therapeutic after an extended period following in-vivo implantation.

MATERIALS AND METHODS Twelve patients received a gentamicin-loaded, articulating spacer between a first- and second-stage revision total knee arthroplasty. At the second stage procedure, synovial fluid and blood samples were collected and assayed for the presence of gentamicin. The second-stage revision occurred at a median of 99 days following the spacer insertion.

RESULTS The median intra-articular gentamicin levels were 0.46 mg/L (0.24 to 2.36 mg/L), which would be considered therapeutic. There were no cases of re-infection.

CONCLUSIONS In this study, preformed articulating spacers containing gentamicin provided therapeutic concentrations in the synovial fluid surrounding the joint throughout the period of implantation. This data confirms the observations from in-vitro studies where a prolonged elution profile was observed for such spacers (Spacer K, Tecres SpA, Italy. InterSpace Knee, Exactech, Inc. USA).

KEY QUOTE “It is therefore interesting to see potentially therapeutic levels of gentamicin at an average of 99 days post insertion of the spacer suggesting that good antibiotic levels are maintained around the spacer for most of the time it is in position.”

Coffey MJ, Ely EE, Crosby LA.
J Shoulder Elbow Surg. 2010 Sep;19(6):868-73. doi: 10.1016/j.jse.2010.01.012. Epub 2010 Apr 14.

SUMMARY This study evaluated treating an infected shoulder arthroplasty and primary shoulder sepsis using a commercially-produced, antibiotic-impregnated cement spacer.

MATERIALS AND METHODS Sixteen shoulders in 15 patients with infected arthroplasty or osteomyelitis of the proximal humerus were treated with irrigation and debridement; hardware removal, humeral head resection, or both; and placement of an interval articulating hemiarthroplasty with a commercially-made, gentamicin-impregnated cement spacer (InterSpace Shoulder, Exactech, Inc. USA).

RESULTS The mean follow-up was 20.5 months after spacer placement. At the time of debridement, 12 shoulders had positive cultures; the most common organisms were methicillin-resistantStaphylococcus aureus (n = 3) and S. epidermidis (n= 3). Twelve patients underwent revisions while four refused revisions and have retained antibiotic spacers. There was no recurrence of infection.

CONCLUSIONS Treatment of glenohumeral sepsis with a commercially-produced, antibiotic-impregnated cement spacer appears to be an effective treatment modality and serum interleukin-6 levels appear to be useful in the evaluation of shoulder infection.

KEY QUOTE “The incidence of reinfection in our series of 16 infected shoulders was zero, whereas the incidence in other series of infected shoulders treated with staged revision arthroplasty with an antibiotic spacer ranges from 0 to 40 percent. In addition to absence of reinfection, patients in our series demonstrated clinical improvements with regards to visual analog pain scale, range of motion, and other subjective and objective shoulder evaluation scores.”

Wan Z, Karim A, Momaya A, Incavo SJ, Mathis KB.J Arthroplasty. 2012 Sep; 27(8):1469-73. doi: 10.1016/j.arth.2012.01.027. Epub 2012 Mar 14.

SUMMARY Two-stage revision arthroplasty using articulating spacers for the treatment of infected total knee arthroplasty (TKA) is a successful management technique. Our purpose was to report our results using preformed, commercially-available articulating spacers made of gentamicin-impregnated cement (Spacer K, Tecres S.p.A. Italy. InterSpace Knee, Exactech, Inc.USA).

MATERIALS AND METHODS Thirty-three patients with an infected primary or revision TKAs were treated with these spacers using a two-stage revision technique. In most cases, the spacers were modified intraoperatively by adding a stem of reinforced antibiotic-impregnated acrylic cement.

RESULTS Successful eradication was achieved in 30 of 33 cases at a minimum two-year follow-up interval. Two patients required a second spacer before a successful TKA revision. No spacer fractures or dislocations occurred in this series. No adverse soft tissue effects were noted from the use of this type of articulating spacer.

KEY QUOTE “Our lower eradication rate (91 percent) compares favorably with other reports even with the inclusion of more complex cases involving multiple previous surgeries, resulting in longer times of active infection as well as compromised bone and soft tissue.”

Degen RM, Davey JR, Davey JR, Howard JL, McCalden RW, Naudie DD.
Clin Orthop Relat Res. 2012 Oct;470(10):2724-9. doi: 10.1007/s11999-012-2350-3.

SUMMARY Treating deep infection following THA has been a challenge. While the standard treatment has remained a two-stage revision, spacer designs, incorporated antibiotics and concentrations have varied. Since control of infection may relate to the choice and concentration of antibiotics, it is important to report rates of control from various spacers. This study determined the rate of infection control and complications associated with a prefabricated, load bearing, gentamicin-impregnated hip spacer (Spacer G, Tecres S.p.A. Italy. Inter-Space Hip, Exactech, Inc. USA) in treating per prosthetic hip infections.

MATERIALS AND METHODS Thirty-three patients with periprosthetic THA infections were retrospectively reviewed and treated with a prefabricated, partial load bearing, gentamicin-impregnated hemiarthroplasty spacer. Thirty of the 33 patients underwent second-stagere implantation after a mean of 15 weeks. Patient demographic data; laboratory values; infecting organism; size of spacer; antibiotic selection; complications; and infection control rates from two academic centers were collected. Recurrent infection at last follow-up was determined by the presence of physical symptoms or signs or elevated serologic tests. The minimum follow-up was 24 months (mean- 43 months; range- 24–70 months).

RESULTS Twenty-eight of the 30 patients who underwent reimplantation remained infection free at last follow-up. One patient became reinfected with a different organism secondary to wound problems. Another became reinfected with the same organism, but was restaged with the prefabricated spacer used in this study, reimplanted, and subsequently remained free of infection. Two of the 33 patients had persistently elevated inflammatory markers at the completion of the first stage and were restaged with this spacer. Both underwent reimplantation and remained free of infection at latest follow-up. One of the 33 patients was satisfied and ambulatory with their spacer. There were no major complications.

CONCLUSIONS Overall, the data supports the use of a partial load bearing, gentamicin-impregnated hemiarthroplasty spacer in treating deep periprosthetic THA infections.

KEY QUOTE “In the end, infection control was ultimately achieved in 3 2of 33 (97 percent) patients.”