How To Diagnose and Treat Infection in Total Ankle Arthroplasty

Diagnosis and Management of Periprosthetic Joint Infections After Total Ankle Arthroplasty

Periprosthetic joint infection (PJI) after total ankle arthroplasty (TAA) is a dreaded complication that may lead to catastrophic outcomes. Risk factors include a history of surgery on the operated ankle, low preoperative function scores, diabetes, extended surgical time, and postoperative wound-healing problems. Clinical presentation varies and may include increasing ankle pain and swelling, high temperature, local erythema, wound drainage, and dehiscence. The initial diagnostic evaluation should include plain radiographs, erythrocyte sedimentation rate, C-reactive protein levels, and leukocyte count. In suspected cases with elevated erythrocyte sedimentation rate and C-reactive protein, aspiration of the ankle joint for synovial fluid analysis, Gram staining, and culture should be performed. Antibiotic therapy should be based on the pathogen identified, and the surgical strategy should be determined based on the time lines of PJI. Early PJI can be treated with irrigation and débridement with polyethylene exchange. The surgical treatment of choice for late PJI is two-stage revision arthroplasty, which includes removal of the implant, insertion of an antibiotic spacer, and reimplantation of a TAA. In certain chronic PJI cases, permanent articulating antibiotic spacers can be left in place or an ankle arthrodesis can be performed. Below-knee amputation is considered as the final option after limb-sparing procedures have failed.

Diagnosis and Management of Infected Total Ankle Replacements

As the number of primary total ankle replacements increases for treatment of end-stage ankle arthritis, failures are also expected to rise. Periprosthetic joint infection is among the causes of failures and has been reported to be as high as 5%. Diagnosis is usually made by a combination of clinical examination findings, imaging, laboratory, and microbiological workup. Management is generally separated into limb salvage or amputation. Limb salvage can be challenging and may involve a single versus staged approach. Options include revision arthroplasty or arthrodesis procedures (ankle versus tibiotalocalcaneal), and a multidisciplinary approach is sought to eradicate infection before definitive management.

Navigating the Challenges of Total Ankle Replacement: Deformity Correction and Infection Considerations

In recent years, total ankle replacement (TAR) has gained widespread acceptance as a surgical treatment for end-stage ankle arthritis. This shift is due to notable improvements in implant design, surgical instrumentation, technique, and surgeon expertise, resulting in high levels of patient satisfaction comparable to ankle fusion. Additionally, indications for TAR have expanded to include advanced deformities that were previously considered unsuitable for the procedure, making ankle arthrodesis the only option. Despite these advancements, TAR still carries a higher complication rate compared to other ankle surgeries. The complex anatomy of the ankle, coupled with limited soft tissue, presents significant challenges in managing complications associated with TAR.

Total Ankle Replacement Infections: A Systematic Review of the Literature

Periprosthetic infection (PJI) after TAR is a serious complication, often requiring further surgery, including revision arthroplasty, conversion to ankle arthrodesis, or even amputation. This systematic review aims to summarize the current evidence on the management of TAR PJI and provide a comprehensive overview of this topic, especially from an epidemiologic point of view. Three different databases (PubMed, Scopus, and Web of Science) were searched for relevant articles, and further references were obtained by cross-referencing. Seventy-one studies met the inclusion criteria, reporting on cases of TAR PJI. A total of 298 PJIs were retrieved. The mean incidence of PJI was 3.8% (range 0.2-26.1%). Furthermore, 53 (17.8%) were acute PJIs, whereas most of them (156, 52.3%) were late PJIs. Most of the studies were heterogeneous regarding the treatment protocols used, with a two-stage approach performed in most of the cases (107, 35.9%). While the prevalence of ankle PJI remains low, it is potentially one of the most devastating complications of TAR. This review highlights the lack of strong literature regarding TAR infections, thus highlighting a need for multicentric studies with homogeneous data regarding the treatment of ankle PJI to better understand outcomes.

A Propensity Score Matched Exploration of Infection in Primary Total Ankle Arthroplasty

BACKGROUND

Infection is a serious complication of primary total ankle arthroplasty (TAA) and can lead to implant failure and revision surgery. Various demographic, comorbidity, and surgical factors have been associated with an increased risk of infection. However, the evidence base remains limited, and further research is needed regarding infection in TAA. This study aims to analyze risk factors of infection and explore outcomes following infected TAA.

METHODS

A retrospective cohort study was conducted using data from a single institution from 2002 to 2022. Patients who underwent primary TAA and had subsequent infection were identified through annual registry surveillance and matched using propensity score matching (PSM) based on various demographic, comorbidity, and surgical factors. Demographics were compared between the matched groups using Mann-Whitney U test and Fisher exact test. The outcomes following infection were identified and summarized using descriptive statistics.

RESULTS

A total of 1863 patients who underwent primary TAA were identified, and 19 were diagnosed with an infection. The identifiable overall infection rate was 1.0%. After PSM, there were no significant differences in the difference in age, gender, BMI, and smoking status between the infected and control cohort. There was a statistically significant increase in the rate of diabetes in the infected cohort. The subsequent surgical intervention resulted in limb salvage in 18 (94.7%) cases. Out of the total number of cases, 2-stage revision to total ankle replacement was performed in 7 cases, whereas revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. One patient had to undergo amputation; however, at the time of the most recent follow-up, all patients were found to be free of infection.

CONCLUSION

This study demonstrated high rates of a history of smoking and diabetes in the infected TAA cohort. The diabetes rate in the infected group was significantly higher than the noninfected controls. Two-stage revision to total ankle replacement was performed in 7 cases, and revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. Overall, a high rate of limb salvage was reported.

LEVEL OF EVIDENCE

Level III, case-control study.

Fusion after a failed primary total ankle arthroplasty

Aims

When a total ankle arthroplasty (TAA) fails, it can be converted to a fusion or a revision arthroplasty. Despite the increasing numbers of TAAs being undertaken, there is little information in the literature about the management of patients undergoing fusion following a failed TAA. The primary aim of this study was to analyze the survival of fusions following a failed TAA using a large dataset from the National Joint Registry (NJR).

Methods

A data linkage study combined NJR and NHS Digital data. Failure of a TAA was defined as a fusion, revision to a further TAA, or amputation. Life tables and Kaplan-Meier graphs were used to record survival. Cox proportional hazards regression models were fitted to compare the rates of failure.

Results

A total of 131 patients underwent fusion as a salvage procedure following TAA. Their mean age was 65.7 years (SD 10.6) and 73 (55.7%) were male. The mean follow-up was 47.5 months (SD 27.2). The mean time between TAA and fusion was 5.3 years (SD 2.7). Overall, 32 (24.4%) underwent reoperations other than revision and 29 (22.1%) failed. Of these 24 (18.3%) underwent revision of the fusion and five (3.8%) had a below-knee amputation. No patients underwent conversion to a further TAA. Failure usually occurred in the first three postoperative years with one-year survival of fusion being 96.0% (95% confidence interval (CI) 90.7 to 98.3) and three-year survival in 69 patients being 77.5% (95% CI 68.3 to 84.4).

Conclusion

Salvage fusion after a failed TAA shows moderate rates of failure and reoperations. Nearly 25% of patients required revision within three years. This study is an extension of studies using the same methodology reporting the failure rates and risk factors for failure, which have recently been published, and also one reporting the outcome of revision TAA for a failed primary TAA, using the same methodology, which will shortly be published.

Magnetic Resonance Imaging of Total Ankle Arthroplasty: State-of-The-Art Assessment of Implant-Related Pain and Dysfunction

Total ankle arthroplasty (TAA) is an effective alternative for treating patients with end-stage ankle degeneration, improving mobility, and providing pain relief. Implant survivorship is constantly improving; however, complications occur. Many causes of pain and dysfunction after total ankle arthroplasty can be diagnosed accurately with clinical examination, laboratory, radiography, and computer tomography. However, when there are no or inconclusive imaging findings, magnetic resonance imaging (MRI) is highly accurate in identifying and characterizing bone resorption, osteolysis, infection, osseous stress reactions, nondisplaced fractures, polyethylene damage, nerve injuries and neuropathies, as well as tendon and ligament tears. Multiple vendors offer effective, clinically available MRI techniques for metal artifact reduction MRI of total ankle arthroplasty. This article reviews the MRI appearances of common TAA implant systems, clinically available techniques and protocols for metal artifact reduction MRI of TAA implants, and the MRI appearances of a broad spectrum of TAA-related complications.

Inflammatory response in confirmed non-diabetic foot and ankle infections: A case series with normal inflammatory markers

BACKGROUND

The distinction between foot and ankle wound healing complications as opposed to infection is crucial for the appropriate and efficacious allocation of antibiotic therapy. Multiple reports have focused on the diagnostic accuracy of different inflammatory markers, however, mainly in the diabetic population.

AIM

To evaluate the diagnostic accuracy of white cell count (WCC) and C-reactive protein (CRP) as diagnostic tools for this distinction in the non-diabetic cohort.

METHODS

Data was reviewed from a prospectively maintained Infectious Diseases Unit database of 216 patients admitted at Leicester University Hospitals–United Kingdom with musculoskeletal infections over the period between July 2014 and February 2020 (68 mo). All patients with confirmed diagnosis of diabetes were excluded while only those with confirmed microbiological or clinical diagnosis of foot or ankle infection were included in our study. For the included patients, we retrospectively retrieved the inflammatory markers (WCCs and CRP) at the time of presentation. Values of CRP 0-10 mg/L and WCC 4.0-11.0 × 10⁹/L were considered normal.

RESULTS

After exclusion of patients with confirmed diabetes, 25 patients with confirmed foot or ankle infections were included. All infections were confirmed microbiologically with positive intra-operative culture results. 7 (28%) patients with osteomyelitis (OM) of the foot, 11 (44%) with OM of the ankle, 5 (20%) with ankle septic arthritis and 2 (8%) patients with post-surgical wound infection were identified. Previous bony surgery was identified in 13 (52%) patients, either a corrective osteotomy or an open reduction and internal fixation for a foot or ankle fracture with the infection developing on top of the existing metalwork. 21 (84%) patients did have raised inflammatory markers while 4 (16%) patients failed to mount an inflammatory response even with subsequent debridement and removal of metal work. CRP sensitivity was 84%, while WCC sensitivity was only 28%.

CONCLUSION

CRP has a relatively good sensitivity in the diagnosis of foot and ankle infections in non-diabetic patients, whereas WCC is a poor inflammatory marker in the detection of such cases. In presence of clinically high level of suspicion of foot or ankle infection, a normal CRP should not rule out the diagnosis of OM.

Time to Revision After Periprosthetic Joint Infection in Total Ankle Arthroplasty: A Systematic Review

While not a common complication after total ankle arthroplasty (TAA), periprosthetic joint infection (PJI) presents a significant risk of implant failure. The primary aim of this systematic review was to evaluate time to revision after PJI in patients who had undergone TAA. An extensive search strategy via electronic databases initially captured 11,608 citations that were evaluated for relevance. Ultimately, 12 unique articles studying 3040 implants met inclusion criteria. The time to revision surgery due to PJI was recorded for each study and a weighted average obtained. The prevalence of PJI was 1.12% (n = 34). We found that the average time to revision due to PJI was 30.7 months, or approximately 2.6 years after the index TAA procedure. By literature definitions, the majority of cases (91.2%, n = 31) were beyond the "acute" PJI phase. The population was divided into 2 groups for further analysis of chronic infections. PJIs before the median were classified as "early" and those after as "late" chronic. The majority of cases (61.8%) were late chronic with an average time to revision of 44.3 months. A smaller number were early chronic (29.4%) with revision within 10.8 months. After summarizing the rates of infection and times to revision reported in the literature, we suggest modifying the current PJI classification to include early chronic and late chronic subgroups so that the total ankle surgeon is better prepared to prudently diagnose and treat PJIs.

Is debridement really the best we can do for periprosthetic joint infections following total ankle replacements? A systematic review and meta-analysis

BACKGROUND

Ankle periprosthetic joint infections are rising in number, but an evidence-based gold standard treatment has not been defined yet.

METHODS

We made a systematic review about the operative treatment of infections following total ankle arthroplasty. Proportional meta-analysis was used to summarize effects of the surgical techniques included. Primary outcome of this study was infection eradication, followed by complications, re-interventions, amputation rates and functions.

RESULTS

We included six studies(113 patients) reporting 6 types of surgical interventions, mostly irrigation and debridement (35.4%) and two-stage revisions (24.8%). No differences among all analyzed techniques were found in the infection eradication outcome as well as in the secondary outcomes. Patients receiving a permanent spacer are most likely to end up with amputation.

CONCLUSIONS

Literature dealing with infections after total ankle replacement is currently composed by few low-quality articles. The overlapping of confidence intervals related to all analyzed interventions showed no superiority of either technique.

LEVEL OF EVIDENCE

III.

Projections and Epidemiology of Total Ankle and Revision Total Ankle Arthroplasty in the United States to 2030

Background: Total ankle arthroplasty (TAA) utilization is increasing in the United States. As the incidence of this procedure grows, it is important for providers to understand the future projections for ankle arthroplasty and more importantly revision total ankle arthroplasty (rTAA). Methods: The National Inpatient Sample (USA) was queried from 2005 to 2017 for all TAA and rTAA. Poisson and linear regression analysis was performed to project annual incidence of TAA and rTAA to 2030, with subgroup analyses on septic rTAA. Results: There were 5315 TAAs performed in 2017, a 564% (P < .001) increase when compared with the TAAs performed in 2005. From 2017 to 2030, the incidence of TAAs is projected to increase from 110% to 796% (P < .001). There were 1170 rTAAs performed in 2017, a 155% (P < .001) increase when compared with rTAAs performed in 2005. There was a 256% increase in the incidence of septic rTAAs from 2005 to 2017 with a projected increase between 22% and 120% by 2030. Conclusions: The incidence of both TAAs and rTAAs is projected to significantly increase over the next decade. Given the known risk factors of TAA and rTAA, these findings reinforce the need for thoughtful consideration when selecting patients for TAA.

Periprosthetic ankle infection: eradication rate, complications, and limb salvage. A systematic review

BACKGROUND

This systematic review investigated the outcomes of revision surgery after periprosthetic ankle infection (PAI).

METHODS

According to the PRISMA statement, 9 studies with 131 PAIs surgically treated and analyzed were included. Demographics and surgical techniques with eradication rates and complications were reported.

RESULTS

Methicillin-sensitive Staphylococcus aureus (MSSA) (30.4%) and coagulase-negative Staphylococcus (CNS) (26.5%) were the most common microorganisms. The eradication rate was 91.7% with permanent antibiotic spacers (SPC), 84.4% with 2-stage, 79.4% with arthrodesis (AA), and 58.8% with debridement and implant retention (DAIR). DAIR showed a significantly lower eradication rate than 2-stage (p = 0.016) and SPC (p = 0.043). Amputations occurred in 25% of patients after SPC, 8.8% after AA and 3.9% after DAIR. SPC showed a significantly higher amputation rate than DAIR and 2-stage (p = 0.044, and p = 0.017, respectively).

CONCLUSIONS

SPC and 2-stage revision show the highest eradication rates, but 2-stage has a lower risk of amputation.

Evaluating and Managing the Painful Total Ankle Replacement

The number of total ankle replacements (TARs) performed in the United States has dramatically increased in the past 2 decades due to improvements in implant design and surgical technique. Yet as the prevalence of TAR increases, so does the likelihood of encountering complications and the need for further surgery. Patients with new-onset or persistent pain after TAR should be approached systematically to identify the cause: infection, fracture, loosening/subsidence, cysts/osteolysis, impingement, and nerve injury. The alignment of the foot and ankle must also be reassessed, as malalignment or adjacent joint pathology can contribute to pain and failure of the implant. Novel advanced imaging techniques, including single-photon emission computed tomography and metal-subtraction magnetic resonance imaging, are useful and accurate in identifying pathology. After the foot and ankle have been evaluated, surgeons can also consider contributing factors such as pathology outside the foot/ankle (eg, in the knee or the spine). Treatment of the painful TAR is dependent on etiology and may include debridement, bone grafting, open reduction and internal fixation, realignment of the foot, revision of the implants, arthrodesis, nerve repair/reconstruction/transplantation surgery, or, in rare cases, below-knee amputation.Level of Evidence: Level V, expert opinion or review.

Two-Staged Revision Total Ankle Arthroplasty Surgery with Primary Total Ankle Arthroplasty System: A Case Report

CASE

Case of a 2-staged revision surgical technique for the treatment of an aseptic total ankle arthroplasty (TAA) loosening: first surgery: removal of the loosened and painful TAA Scandinavian Total Ankle Replacement, with exclusion of infection, and reconstruction of the large bone defect (bone-defect downsizing surgery); proof of successful ankle bone reconstruction by CT-scan imaging; second surgery: implantation of a primary VANTAGE TAA (ankle reconstruction with new primary TAA).

CONCLUSION

The present case shows the management of a failed TAA with bone defect by performing a 2-step surgical approach: removal of loosened TAA with simultaneous bone stock restoration and then implantation of a new primary TAA. This concept is a possible alternative to a post-TAA ankle arthrodesis or to the use of a TAA revision system.

Salvage Tibiotalocalcaneal Arthrodesis Augmented With Fibular Columns and Iliac Crest Autograft: A Technical Note

Failure of ankle arthrodesis or total ankle replacement (TAR) results in a challenging clinical situation and may take the form of symptomatic nonunion following arthrodesis and aseptic or infective loosening following TAR. Revision in these scenarios is technically demanding, and if associated with subtalar degeneration, conversion to tibiotalocalcaneal (TTC) arthrodesis may be required, with use of bone grafting to maintain length and reduce disability. Fibular strut grafting in the form of pillars or columns, potentially supplemented by tricortical and iliac graft, may be used in association with intramedullary TTC nailing or lateral plating and has demonstrated encouraging fusion rates. In this technical note, we review the history of this technique and report indications and surgical approach. Furthermore, of 6 cases (mean age 69.8 years) treated at our institution and followed at 13 months (range, 8 to 20 months), 5 (83%) were clinically and radiologically united, and patients were satisfied with the outcome of surgery. One patient with a background of chronic kidney disease remained dissatisfied with no union achieved, persistent pain, and awaiting a below-the-knee amputation. No other complications were observed. TTC fusion augmented with fibular columns and iliac crest autograft is an option to treat combined ankle and subtalar joint pathologies with significant talar bone loss.Levels of Evidence: Level V (technical note).

The Use of Closed Incision Negative Pressure Therapy Immediately After Total Ankle Arthroplasty Surgeries

Introduction Total ankle arthroplasty (TAA) has become a common procedure in the treatment of end-stage ankle arthritis. Most prostheses utilize an anterior ankle approach, which has been shown to have incisional complication rates of up to 28%, including dehiscence and infection. Wounds in this area can be catastrophic to patient outcomes. Preventing incisional wounds would significantly benefit the patient. The purpose of this study was to evaluate the effect of closed incision negative pressure therapy (ciNPT) in reducing incisional dehiscence and surgical site infection (SSI) after TAA. Materials and methods A retrospective chart review that was approved by the Institutional Review Board (IRB) was performed on patients undergoing TAA. Inclusion criteria were patients undergoing TAA with an anterior incision and ciNPT placed immediately in the operating room. Comorbidities associated with increased wound complications were recorded. Identification of any incisional dehiscence, infections, or deviations from normal postoperative recovery attributed to the former was also recorded. Results Twenty-eight patients met the inclusion criteria. The average age of the patients at the time of surgery was 68 years. Comorbidities associated with compromised healing were obesity (45%), current or former smoking (45%), diabetes (3.5%), and rheumatoid arthritis (7%). There were no postoperative wound complications (100% incisional healing). No patient required any wound-care intervention or had an SSI. None of the patients had any delay in the normal postoperative course. Conclusion Avoiding wound complications in TAA patients is critical to the success of the procedure. This retrospective case series demonstrated 100% healing with the utilization of the ciNPT in both normal and high-risk patients with decreased healing potential. Our results showed a substantial decrease in wound complications and SSIs compared to historical reports. We recommend ciNPT for all TAA procedures utilizing an anterior incision to decrease the risk for wound complications and SSIs.

Multidisciplinary Diagnostic Algorithm for Evaluation of Patients Presenting with a Prosthetic Problem in the Hip or Knee: A Prospective Study

The predominant indications for revision surgery after total hip (THA) or knee arthroplasty (TKA) are an aseptic failure (AF) and prosthetic joint infection (PJI). Accurate diagnosis is crucial. Therefore, we evaluated prospectively a multidisciplinary diagnostic algorithm including multi-modal radionucleid imaging (RNI) and extended microbiological diagnostics. If the surgeon suspected PJI or AF, revision surgery was performed with multiple samples obtained in parallel for special culture procedures and later molecular analyses. Alternatively, if the underlying cause was not evident, RNI was scheduled comprising ⁹⁹Tc—HDP SPECT/CT, ¹¹¹In-labeled white blood cells combined with ⁹⁹Tc-nanocoll bone marrow SPECT/CT, and ¹⁸F-FDG PET/CT. A multidisciplinary clinical team made a recommendation on the indication for a diagnostic procedure guided by RNI images or revision surgery. A total of 156 patients with 163 arthroplasties were included. Fifty-five patients underwent RNI. In all, 118 revision surgeries were performed in 112 patients: 71 on the indication of AF and 41 revision of PJI. Thirty-four patients were concluded with chronic pain, and revision surgery refrained. The effective median follow-up period was 13 months. A structured approach offered by the algorithm was useful for the clinician in the evaluation of patients with a failing TKA or THA. Surgical revision was possibly obviated in approximately 20% of patients where an explanation or cause of failure was not found. The algorithm served as an effective tool.

Postoperative Chronic Osteomyelitis in the Long Bones - Current Knowledge and Management of the Problem

Chronic postoperative osteomyelitis represents an important health problem due to its significant morbidity and low mortality rate. This pathology is challenging because of difficulties in understanding the pathogenesis and the decision-making involving the treatment. The present article had the goal of reviewing the definition, pathogenesis, clinical aspects, diagnosis, and treatment of chronic postoperative osteomyelitis, and of gathering this information in a single Brazilian updated publication.

The PubMed, LILACS, and the Cochrane Library medical databases were analyzed using pertinent keywords. Current and relevant articles were selected.

The present article gathered the established information, as well as innovations related to chronic osteomyelitis and its treatment, to offer updated data to assist the professionals involved in the management of chronic osteomyelitis.

The Impact of α-Defensin Test in Diagnosing Periprosthetic Infection After Total Ankle Arthroplasty

Periprosthetic joint infection (PJI) after total ankle arthroplasty (TAA) is a serious complication, and a reliable diagnostic test to identify PJI is needed. The purpose of this study was to investigate the use of synovial α-defensin levels in identifying PJI of the ankle. Data from 33 patients were retrospectively collected between September 2015 and May 2018. Patients who had pain or suspected loosening after TAA and who had undergone joint aspiration were included in the study. Aspiration was performed in a semisterile theatre. Synovial fluid was processed in descending order for microbiological cultures, α-defensin, leukocyte esterase strip test, and cell count. A periprosthetic infection was defined by Musculoskeletal Infection Society criteria. The sensitivity, specificity, and overall accuracy were calculated, and based on a receiver operating characteristic curve, the quality of the α-defensin test was determined. The calculated area under the curve was 0.97 ± 0.32. Two of 33 patients fulfilled the 2014 Musculoskeletal Infection Society criteria and were scheduled for septic revision arthroplasty. Sensitivity, specificity, and overall accuracy of the α-defensin test were 100% (95% confidence interval [CI], 15.8% to 100%), 93.5% (95% CI, 78.6% to 99.2%), and 93.9% (95% CI, 79.8% to 99.3%), respectively. The positive predictive value was 50% (95% CI, 20.7% to 79.3%), and the negative predictive value was 100%. The α-defensin test seems to be the best available synovial test to detect a late-onset PJI after total ankle arthroplasty. Further prospective studies with a larger number of patients are required.

Infection Protocols for Implants

Infection can be a devastating complication of surgically inserted prosthetic implants and intramedullary rods, plates and pins. About 2 million implants were inserted in the United States in 2004, and, despite appropriate perioperative antibiotics, approximately 5% of internal fixation devices became infected. Infection rates in fractures that pierce the skin can be as high as 22.7%. Complications of infection include excessive antibiotic use, implant removal, reoperation, and potential amputation. Infections caused by colonized prosthetic implants are often difficult to predict, diagnose, and treat, because they form biofilms. This article explores the approach to infected implants.

Factors to Consider When Assessing the Diagnostic Accuracy of Synovial Leukocyte Count in Periprosthetic Joint Infection

Synovial white blood cell (WBC) count and the percentage of polymorphonuclear leucocytes (PMN%) is one of the diagnostic criteria to diagnose a periprosthetic joint infection (PJI). Although the test is widely available, the diagnostic accuracy of proposed cut-off levels are influenced by several factors, such as: the affected joint, co-morbid conditions, the causative microorganism and the gathering and processing of samples in the laboratory. In this narrative review we provide an overview on how and to what extent these factors can affect the synovial WBC count and PMN% in synovial fluid.

What Metrics Can Be Used to Determine the Optimal Timing of Reimplantation in Patients Who Have Undergone Resection Arthroplasty as Part of a Two-Stage Exchange for Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

There is no conclusive data regarding what metrics can be used in order to determine the optimal timing of reimplantation for an infected TAA. We recommend that reimplantation is performed when there are clinical signs of resolution of infection (well-healed wound, lack of erythema, etc), and the serologic markers have substantially declined (>40%) from baseline (measured at the time of diagnosis of infection).

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Should Aspiration of the Ankle With an Antibiotic Spacer Be Performed Prior to Reimplantation?

RECOMMENDATION

We recommend that aspiration of the ankle with an antibiotic spacer prior to a second-stage reimplantation be strongly considered. Available studies indicate that a positive culture of the aspirate in this setting is predictive of residual infection, while a negative aspirate culture does not rule out infection and should be interpreted in light of other clinical indicators and laboratory values.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 92%, Disagree: 8%, Abstain: 0% (Super Majority, Strong Consensus).

What Are the Indications for Aspiration of a Possibly Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

Whenever a periprosthetic joint infection (PJI) of a total ankle arthroplasty (TAA) is clinically possible or suspected, especially when elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) levels exist, and in correspondence to the literature on PJI in total hip and knee arthroplasties, joint aspiration is indicated.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Is There a Role for Measuring Synovial Biomarkers for Diagnosis of Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

Based on the hip and knee arthroplasty literature, measuring synovial biomarkers may play a role in the diagnosis of infected total ankle arthroplasty (TAA). The diagnosis of periprosthetic joint infection (PJI) in the setting of a TAA can be confirmed with cultures, provided that a plausible pathogen is recovered in the context of a compatible clinical picture. In the absence of a positive culture, synovial biomarker analysis may help in establishing the diagnosis.

LEVEL OF EVIDENCE

Moderate.

DELEGATE VOTE

Agree: 92%, Disagree: 8%, Abstain: 0% (Super Majority, Strong Consensus).

What Is the Optimal (Type, Dose and Route of Administration) Antibiotic Treatment for Patients With Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

Though literature specific to total ankle arthroplasty (TAA) is lacking, based on recommendations for the management of hip and knee arthroplasties, the choice of antibiotic should be made based on the identification and sensitivities of the infecting organism(s). Dosing, frequency, and route of administration of antibiotics may be determined in consultation with an infectious disease specialist and by taking into account the patient's weight and comorbidities, such as renal impairment and the antibiogram.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

What Is the Definition of Acute and Chronic Periprosthetic Joint Infection (PJI) of Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

There is a paucity of data for defining acute or chronic periprosthetic joint infection (PJI) following total ankle arthroplasty (TAA) in the literature. Any discussion of PJI after ankle replacement is entirely reliant on the literature surrounding knee and hip arthroplasty.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

What Is the Diagnostic "Algorithm" for Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

Patients who present with clinical symptoms and signs of periprosthetic ankle infection (pain, erythema, warmth, sinus tract, abscess around the wound) and sinus tracts communicating with the ankle/subtalar joint are likely to have total ankle arthroplasty (TAA) infection. In the absence of a sinus tract, elevated inflammatory markers (erythrocyte sedimentation rate [ESR] and C-reactive protein [CRP]) should prompt ankle joint aspiration for cell count, differential, and culture. The joint aspiration is to be repeated. If the same organism is identified in at least 2 cultures of synovial fluid, the patient is diagnosed to have an infection. If the repeat aspiration is negative, further investigation is warranted. In patients not requiring operative intervention for other reasons, nuclear imaging should be considered for diagnosis. If an operation is indicated, histologic examination (>5 neutrophils/high-power field) or synovial fluid analysis is conducted to confirm infection.

LEVEL OF EVIDENCE

Limited.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Total Replacement of Varus Ankle: Three-Component Prosthesis Design

In the past few decades, total ankle replacement (TAR) has become an increasingly recommended and accepted treatment in patients with end-stage ankle osteoarthritis. However, controversy still exists about the appropriate indications for TAR, specifically in ankles with coronal plane deformities. Although not explicitly proved, the long-term success of TAR seems to largely depend on the extent to which the surgeon is able to balance the ankle joint complex.

Diagnostic Criteria and Treatment of Acute and Chronic Periprosthetic Joint Infection of Total Ankle Arthroplasty

Background:

Prosthetic joint infection (PJI) after total ankle arthroplasty (TAA) is a serious complication that results in significant consequences to the patient and threatens the survival of the ankle replacement. PJI in TAA may require debridement, placement of antibiotic spacer, revision arthroplasty, conversion to arthrodesis, or potentially below the knee amputation. While the practice of TAA has gained popularity in recent years, there is some minimal data regarding wound complications in acute or chronic PJI of TAA. However, of the limited studies that describe complications of PJI of TAA, even fewer studies describe the criteria used in diagnosing PJI. This review will cover the current available literature regarding total ankle arthroplasty infection and will propose a model for treatment options for acute and chronic PJI in TAA.

Methods:

A review of the current literature was conducted to identify clinical investigations in which prosthetic joint infections occurred in total ankle arthroplasty with associated clinical findings, radiographic imaging, and functional outcomes. The electronic databases for all peer-reviewed published works available through January 31, 2018, of the Cochrane Library, PubMed MEDLINE, and Google Scholar were explored using the following search terms and Boolean operators: “total ankle replacement” OR “total ankle arthroplasty” AND “periprosthetic joint infection” AND “diagnosis” OR “diagnostic criteria.” An article was considered eligible for inclusion if it concerned diagnostic criteria of acute or chronic periprosthetic joint infection of total ankle arthroplasty regardless of the number of patients treated, type of TAA utilized, conclusion, or level of evidence of study.

Results:

No studies were found in the review of the literature describing criteria for diagnosing PJI specific to TAA.

Conclusions:

Literature describing the diagnosis and treatment of PJI in TAA is entirely reliant on the literature surrounding knee and hip arthroplasty. Because of the limited volume of total ankle arthroplasty in comparison to knee and hip arthroplasty, no studies to our knowledge exist describing diagnostic criteria specific to total ankle arthroplasty with associated reliability. Large multicenter trials may be required to obtain the volume necessary to accurately describe diagnostic criteria of PJI specific to TAA.

Level of Evidence:

Level III, systematic review.

Outcomes of Acute Hematogenous Periprosthetic Joint Infection in Total Ankle Arthroplasty Treated With Irrigation, Debridement, and Polyethylene Exchange

BACKGROUND

Acute hematogenous periprosthetic joint infection (PJI) is defined in the literature as infection diagnosed and treated within 2 to 4 weeks from the onset of symptoms. In total hip and knee arthroplasty, irrigation and debridement (I&D) and polyethylene exchange with component retention has been studied extensively. However, there is minimal literature evaluating this treatment method for PJI in total ankle arthroplasty (TAA). The purpose of this study was to evaluate both the clinical and patient-reported outcomes and survivorship of TAA acute hematogenous PJIs treated with I&D and polyethylene exchange.

METHODS

A single-center, retrospective chart review of prospectively collected data in patients with TAA PJI who subsequently underwent I&D and polyethylene exchange with retention of metal components was conducted. The primary outcome was failure rate of I&D and polyethylene exchange, where failure was defined as subsequent removal of all components and 2-stage revision or arthrodesis. Patient-reported outcomes collected before primary arthroplasty, after primary arthroplasty, and after polyethylene exchange were also analyzed.

RESULTS

We identified 14 patients with acute hematogenous PJI who underwent I&D and polyethylene exchange with retention of metal components. The mean time from primary TAA to symptoms was 43 months (range 1-147 months). The average time from onset of symptoms to I&D and polyethylene exchange was 11.4 ± 5.6 days. The mean follow-up after this surgery was 2.8 ± 1.5 years. The long-term failure rate was 54%. The most common bacteria isolated in patients who failed was methicillin-resistant Staphylococcus aureus (MRSA). The most common bacteria isolated in patients who retained their implants was methicillin-sensitive Staphylococcus aureus (MSSA). Visual analog scale (VAS), Short Musculoskeletal Function Assessment (SMFA), Short Form-36 (SF-36), and American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scale showed significant improvement when compared to preoperative scores in patients who retained their implants both after primary and after I&D and polyethylene exchange.

CONCLUSIONS

I&D and polyethylene exchange with retention of metal components has a long-term survivorship comparable to those reported in the total knee and total hip arthroplasty literature. Patient-reported outcomes after I&D and polyethylene exchange were comparable to those collected after primary arthroplasty in those patients who ultimately retained their implants. Two variables in this cohort that were associated with I&D and polyethylene exchange failure include time the patient was symptomatic prior to I&D as well as organism isolated on culture. With a failure rate of 54%, the authors recommend thorough evaluation on a case-by-case basis prior to indicating a patient for single-stage I&D with polyethylene exchange.

LEVELS OF EVIDENCE

Level IV, case series.

[Aseptic loosening of total ankle replacement and conversion to ankle arthrodesis]

OBJECTIVE

To remove loosened prosthesis components, to perform augmentation, to address osseous defects, to perform neutrally aligned ankle arthrodesis, and to achieve postoperative pain relief.

INDICATIONS

Symptomatic, aseptic loosening of total ankle replacement (TAR) with/without substantial bone defect of the tibial and/or talar bone stock.

CONTRAINDICATIONS

General surgical or anesthesiological risks, periprosthetic infection, local or systemic infection, nonmanageable soft tissue problems.

SURGICAL TECHNIQUE

Removal of both prosthesis components using the previous incision (mostly using anterior ankle approach). Careful debridement of bone stock at the tibial and talar side. Osseous augmentation of defects using autologous or homologous cancellous bone, if needed, using structural allografts.

POSTOPERATIVE MANAGEMENT

A soft wound dressing is used. Thromboprophylaxis is recommended. Patient mobilization starts on postoperative day 1 with 15 kg partial weight bearing using a stabilizing walking boot or cast for 6-8 weeks. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is initiated gradually after progressive osseous healing has been confirmed.

RESULTS

Between January 2007 and December 2012, ankle arthrodesis was performed in 9 patients with failed TAR (6 men and 3 women, mean age 56.4 ± 7.0 years, range 47.8-66.0 years). The mean time between the initial TAR and revision surgery was 4.5 ± 2.4 years (range 1.2-7.9 years). In one patient irrigation and debridement was performed due to superficial wound infection. Another patient had a delayed osseous healing 11 months after the revision surgery.