Autoclaved metal-on-cement spacer versus static spacer in two-stage revision in periprosthetic knee infection

Indications and techniques for non-articulating spacers in massive bone loss following prosthetic knee joint infection: a scoping review

INTRODUCTION

Prosthetic joint infection (PJI) is a destructive complication of knee replacement surgery (KR). In two-stage revision a spacer is required to maintain limb length and alignment and provide a stable limb on which to mobilise. Spacers may be articulating or static with the gold standard spacer yet to be defined. The aims of this scoping review were to summarise the types of static spacer used to treat PJI after KR, their indications for use and early complication rates.

METHODS

We conducted a scoping review based on the Joanna Briggs Institute's "JBI Manual for Evidence Synthesis" Scoping review reported following Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. MEDLINE, EMBASE and CINAHL were searched from 2005 to 2022 for studies on the use of static spacers for PJI after KR.

RESULTS

41 studies (1230 patients/knees) were identified describing 42 static spacer constructs. Twenty-three (23/42 [54.2%]) incorporated cement augmented with metalwork, while nineteen (19/42, [45.9%]) were made of cement alone. Spacers were most frequently anchored in the diaphysis (22/42, [53.3%]), particularly in the setting of extensive bone loss (mean AORI Type = F3/T3; 11/15 studies 78.3% diaphyseal anchoring). 7.1% (79 of 1117 knees) of static spacers had a complication requiring further surgery prior to planned second stage with the most common complication being infection (86.1%).

CONCLUSIONS

This study has summarised the large variety in static spacer constructs used for staged revision KR for PJI. Static spacers were associated with a high risk of complications and further work in this area is required to improve the quality of care in this vulnerable group.

Selecting a high-dose antibiotic-laden cement knee spacer

Prosthetic joint infection [PJI] after total knee arthroplasty (TKA) remains a common and challenging problem for joint replacement surgeons and patients. Once the diagnosis of PJI has been made, patient goals and characteristics as well as the infection timeline dictate treatment. Most commonly, this involves a two-stage procedure with the removal of all implants, debridement, and placement of a static or dynamic antibiotic spacer. Static spacers are commonly indicated for older, less healthy patients that would benefit from soft tissue rest after initial debridement. Mobile spacers are typically used in younger, healthier patients to improve quality of life and reduce soft-tissue contractures during antibiotic spacer treatment. Spacers are highly customizable with regard to antibiotic choice, cement variety, and spacer design, each with reported advantages, drawbacks, and indications that will be covered in this article. While no spacer is superior to any other, the modern arthroplasty surgeon must be familiar with the available modalities to optimize treatment for each patient. Here we propose a treatment algorithm to assist surgeons in deciding on treatment for PJI after TKA.

Are Static Spacers Superior to Articulated Spacers in the Staged Treatment of Infected Primary Knee Arthroplasty? A Systematic Review and Meta-Analysis

In the treatment of knee periprosthetic joint infection with a two-stage protocol, static spacers allow for the local delivery of high doses of antibiotics and help to preserve soft tissue tension. Articulated spacers were introduced to better preserve flexion after the reimplantation. The aim of this systematic review is to provide a comprehensive data collection of the results of these different spacers. An in-depth search on the main clinical databases was performed concerning the studies reporting data on the topic. A total of 87 studies and 4250 spacers were included. No significant differences were found both in pooling data analysis and meta-analysis of comparative studies about infection recurrences, complications, and clinical scores. Mean active knee flexion at last follow-up after total knee reimplantation was found to be significantly higher using articulated spacers (91.6° ± 7° for static spacers vs. 100.3° ± 9.9° for articulated spacers; p < 0.001). Meta-analysis also recognized this strong significant difference (p < 0.001). This review has confirmed that articulated spacers do not appear to be inferior to static spacers regarding all clinical outcomes, while they are superior in terms of active flexion. However, the low quality of the studies and the risk for selection bias with complex patients preferentially treated with static spacers need to be accounted for.

The autoclaving and re-implantation of an infected prosthesis as a spacer during resection knee arthroplasty: a systematic review

BACKGROUND

Hofmann et al., in 1995, first described an articulating spacer made by cleaning and autoclaving the original femoral component, which is then re-implanted with a new tibial polyethylene. This systematic review aims to assess the state of existing evidence on the intraoperative autoclaving and re-use of an infected prosthesis, as a spacer, during a two-stage revision following Periprosthetic Joint Infections (PJI).

METHODS

A systematic review was conducted with methods described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. OVID-MEDLINE®, EMBASE, Cochrane Library, SCOPUS, Web of Science, Google Scholar and PubMed were searched from 1995 to April 2020 to identify relevant studies.

RESULTS

Fourteen studies were included in this systematic review: two prospective case series; six retrospective comparative studies and six retrospective case series. The reviewed studies included 567 patients (571 knees): 394 patients treated with autoclaved components and 173 with a spacer made of new components. The cumulative re-infection rate in patients treated with re-used autoclaved components was 13.7% (54 re-infections in 394 patients), whereas in control patients the re-infection rate was 13.3% (23 re-infections in 173 patients). The final Range of Movement in patients treated using the autoclaved components as a spacer, compared with patients receiving static spacers, was significantly higher in three out of four comparative studies.

CONCLUSION

There is a moderate level of evidence that the intraoperative autoclaving and re-use of an infected prosthesis as a spacer, during a knee resection arthroplasty, is an effective procedure in the management of knee PJI.

Periprosthetic Knee Infection - Part 2: Treatment

Several treatment modalities are proposed for periprosthetic infections, with variable success rates. However, efficacy is related to the appropriate selection of cases for each type of treatment. Debridement with implant retention is indicated in acute infections with fixed implant, and its success depends on the type of infection, comorbidities of the host, and virulence of the etiological agent. One- or two-stage revision is required in cases in which biofilm is forming, or of implant loosening. The choice between performing the review in one or two stages depends on factors such as etiological agent identification, pathogen virulence, local and systemic host factors. Rescue procedures such as arthrodesis, amputation, resection arthroplasty or even antibiotic suppression are reserved for cases in which the infection has not been eradicated.

Temporary new implant spacers increase post-reimplantation total knee prosthesis survival after periprosthetic joint infection

PURPOSE

Two-stage exchange arthroplasty is considered the gold standard for treatment of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Antibiotic cement spacers can include cement-based spacers (CBS), new components (NEW), and autoclaved components (ACL). The factors that most influence post-reimplantation prosthesis (PRP) survival were determined.

METHODS

A retrospective database review of patients undergoing two-stage exchange arthroplasty from 2008 to 2014 was performed. There were 85 patients, 25 patients and 30 patients in CBS, NEW and ACL groups, respectively. Patient, disease and surgical characteristics were collected and analyzed. Post-reimplantation prosthesis (PRP) survival was modeled using the Kaplan-Meier method. Cox proportional hazard modeling was then performed to identify risk factors associated with implant failure.

RESULTS

Overall PRP survival was 82% in 140 unilateral TKAs. PRP survival between groups was 81%, 96% and 73% within the minimum 2-year follow-up period, respectively. There was a difference in median interval-to-reimplantation between groups (CBS, 72.0 days; NEW, 111.0 days; ACL, 84.0 days, p = 0.003). Adjusting for time-to-reimplantation, NEW spacers demonstrated greater PRP survival compared with ACL spacers (p = 0.044), and a trend towards greater survival compared with CBS spacers (p = 0.086). Excluding early failures (< 90 days), NEW spacers still demonstrated greater survival than ACL spacers (p = 0.046). Lower volume (≤ 10 within this series) surgeons tended to use more CBS spacers, while higher volume surgeons were comfortable with ACL spacers.

CONCLUSIONS

There was greater PRP survival with NEW spacers. NEW spacers also demonstrated an increased inter-stage interval, likely because of increased comfort and motion. There were spacer choice differences between low- and high-volume surgeons.

LEVEL OF EVIDENCE

III.

Functional outcome of two-stage reimplantation in patients with periprosthetic joint infection after primary total knee arthroplasty

INTRODUCTION

Two-stage reimplantation in patients with chronic periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) with the use of either articulating or static antibiotic-loaded spacers during the first step is considered to be the golden standard in orthopaedics.

THE AIM OF THE STUDY

The aim of the study was to evaluate the correlation of spacer type with the infection elimination rate as well as functional outcomes after two-staged revision TKA in patients with PJI.

MATERIALS AND METHODS

The cohort comprised 161 patients who were treated for PJI after TKA during a period from January 2007 to December 2015. After the exclusion of patients with severe bone defects (AORI 2B or 3), 104 were left for the analysis: 72 patients with articulating and 32 with static spacers. The overall patient mean age was 62 years old (95% CI, 30-84): 73 for females, 31 for males. The outcomes were evaluated after three, six and 12 months using the American Knee Society Score (KSS) and EQ-5D. Only 92 patients were available for observation: 25 with static and 67 with articulating spacers.

RESULTS

One year after the surgery, patients with articulating spacers demonstrated significantly higher mean KSS and function scores in comparison to patients with static spacers (90.4, 77.3 and 78.5, 67.8, respectively (p < 0.05)). The range of motion was also significantly better in patients with articulating spacers: 104.9° in comparison to 93.9° (р < 0.0001). The final EQ-5D score was comparable in both groups (0.82, 73.1 in articulating and 0.82, 72.6 in static spacers).

CONCLUSION

The two-stage revision TKA for PJI using articulating spacers in comparison to the static ones provides better infection eradication rate as well as functional outcomes and improved quality of life.

Outcomes of Articulating Spacers With Autoclaved Femoral Components in Total Knee Arthroplasty Infection

BACKGROUND

In 2-stage revision of total knee arthroplasty (TKA) infection, articulating antibiotic spacers show similar eradication rates and superior range of motion compared with static spacers. This study evaluated infection control and other outcomes in articulating spacers with an autoclaved index femoral component.

METHODS

We reviewed 59 patients who underwent 2-stage treatment of TKA infection using articulating antibiotic spacers with an autoclaved femoral component with at least 2-year follow-up (mean: 5.0 years) from spacer placement. Reinfection was defined as any subsequent infection; recurrence was defined as reinfection with the same organism, need for chronic antibiotics, or conversion directly to amputation/arthrodesis.

RESULTS

Nine patients (15%) experienced a recurrence and 22 patients (37%) experienced a reinfection. Incidence of diabetes mellitus was significantly higher in patients who became reinfected. Other comorbidities, revision history, prior spacer, or presence of virulent organisms did not predict infection recurrence. Forty-seven spacers underwent reimplantation, 6 (13%) of these went on to above-knee amputation, 6 (13%) received another 2-stage procedure, and 3 (6%) underwent subsequent irrigation and debridement. Three patients (5%) proceeded directly from spacer to above-knee amputation (2) or arthrodesis (1). Nine spacers (15%) in 7 patients were retained indefinitely (mean: 3.4 years), with overall good motion and function.

CONCLUSION

Accounting for methodology, articulating spacers with autoclaved femoral components provide similar infection control to previous reports. Most patients with reinfection grew different organisms compared with initial infection, suggesting that some subsequent infections may be host related. Some patients retained spacers definitively with overall good patient satisfaction.

Flash autoclave settings may influence eradication but not presence of well-established biofilms on orthopaedic implant material

Flash autoclaving is one of the most frequently utilized methods of sterilizing devices, implants or other materials. For a number of decades, it has been common practice for surgeons to remove implantable devices, flash autoclave and then reimplant them in a patient. Data have not yet indicated the potential for biofilms to survive or remain on the surface of orthopaedic-relevant materials following flash autoclave. In this study, monomicrobial and polymicrobial biofilms were grown on the surface of clinically relevant titanium materials and exposed to flash autoclave settings that included varying times and temperatures. Data indicated that when the sterilization and control temperatures of an autoclave were the same, biofilms were able to survive flash autoclaving that was performed for a short duration. Higher temperature and increased duration rendered biofilms non-viable, but none of the autoclave settings had the ability to remove or disperse the presence of biofilms from the titanium surfaces. These findings may be beneficial for facilities, clinics, or hospitals to consider if biofilms are suspected to be present on materials or devices, in particular implants that have had associated infection and are considered for re-implantation. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1543-1550, 2018.

Evaluation of the role of human β-defensin 3 in modulation of immunity and inflammatory response after knee replacement

The present study investigated the value of human β-defensin 3 (HBD-3) in adjusting the immunity and inflammatory response of T lymphocytes in the body after knee replacement. Sixty-four cases of knee replacement patients were successively selected and randomly divided into the control group and the observation group each with 32 cases. Once a day, for 7 days, patients in the control group were injected with placebo saline solution in the articular cavity. Levels of Th1 and/Th2, interleukin (IL)-2 and IL-10, tumor necrosis factor (TNF)-α, toll-like receptor (TLR)-4, and alkaline phosphatase (ALP) were compared one month later, and implant infection rates were compared within 1-year follow-up. Compared with patients in the control group, the levels of Th1 and Th1/Th2 in the observation group significantly increased, yet their Th2 decreased. The levels of IL-2 and TNF-α were also observed to be significantly elevated, yet IL-10 decreased. Furthermore, their TLR-4 and ALP levels were significantly higher. Three cases of implant-related infection occurred in the control group and 1 case in the observation group. In conclusion, HBD-3 could adjust the immunity and inflammatory response of cells in the body after knee replacement, possibly playing an important role in implant-related infection.