The Role of Receptor Activator of Nuclear Factor-κB Ligand/Osteoprotegerin Ratio in Synovial Fluid as a Potential Marker for Periprosthetic Osteolysis Following Total Ankle Arthroplasty.

Background: Periprosthetic osteolysis is a prevalent complication following total ankle arthroplasty (TAA), implicating various cytokines in osteoclastogenesis as pivotal in this process. This study aimed to evaluate the relationship between osteolysis and the concentrations of osteoclastogenesis-related cytokines in synovial fluid and investigate its clinical value following TAA. Methods: Synovial fluid samples from 23 ankles that underwent revision surgery for osteolysis following TAA were analyzed as the osteolysis group. As a control group, we included synovial fluid samples obtained from 23 ankles during primary TAA for osteoarthritis. The receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio in these samples was quantified using sandwich enzyme-linked immunosorbent assay techniques, and a bead-based multiplex immunoassay facilitated the detection of specific osteoclastogenesis-related cytokines. Results: RANKL levels averaged 487.9 pg/mL in 14 of 23 patients in the osteolysis group, with no detection in the control group's synovial fluid. Conversely, a significant reduction in OPG levels was observed in the osteolysis group (p = 0.002), resulting in a markedly higher mean RANKL/OPG ratio (0.23) relative to controls (p = 0.020). Moreover, the osteolysis group had increased concentrations of various osteoclastogenesis-related cytokines (tumor necrosis factor-α, interleukin [IL]-1ß, IL-6, IL-8, IP-10, and monocyte chemotactic protein-1) in the synovial fluid relative to the control group. Conclusions: Our results demonstrated that periprosthetic osteolysis was associated with osteoclastogenesis activation through an elevated RANKL/OPG ratio following TAA. We assume that RANKL and other osteoclastogenesis-related cytokines in the synovial fluid have clinical value as a potential marker for the development and progression of osteolysis following TAA.

Association of Timing of Hindfoot Arthrodesis and Early Reoperation Rates for Total Ankle Arthroplasty.

BACKGROUND: Prior literature has demonstrated that ipsilateral hindfoot arthrodesis may increase the risk for reoperation after total ankle arthroplasty (TAA) and that simultaneous hindfoot arthrodesis with TAA could result in short-term clinical and radiologic improvements. The purpose of this study is to compare the reoperation rates after TAA with prior hindfoot arthrodesis vs simultaneous arthrodesis and TAA. METHODS: Patients who underwent primary TAA were identified in the PearlDiver database. Patients were sorted into 2 study cohorts: hindfoot arthrodesis prior to TAA and simultaneous arthrodesis and TAA. Propensity matched control cohorts were identified for each study group. Multivariate analysis was conducted to account for any confounding variables and covariates when identifying differences in complications between cohorts. RESULTS: 297 patients underwent TAA with prior hindfoot arthrodesis and 174 underwent TAA and hindfoot arthrodesis concurrently. The incidence of reoperation (13.8% vs 5.2%, P < .001) and infection (12.6% vs 5.9%, P = .011) for the simultaneous cohort was higher when compared to the matched control cohort. In contrast, there was no statistically significant difference when comparing the prior arthrodesis cohort to the matched control cohort in reoperation rates (5.1% vs 4.7%, P = .787) or infection rates (4.4% vs 4.8%, P = .734). Those undergoing simultaneous procedures had increased incidences of reoperation, wound complications, infection, and emergency department visits (P < .0167) when compared to the TAA with prior arthrodesis cohort. CONCLUSION: Patients undergoing TAA and hindfoot arthrodesis concurrently were found to have higher rates of reoperation and infection when compared to the matched control cohort . In contrast, there was no difference in these rates in patients undergoing TAA with prior hindfoot arthrodesis compared with their matched control cohort. Patients undergoing simultaneous procedures had increased rates of reoperations, wound complications, infection, and emergency department visits compared to the TAA with prior arthrodesis cohort.

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.

Bone grafting for periprosthetic bone cysts following total ankle arthroplasty.

Aims: The purpose of this study was to assess the success rate and functional outcomes of bone grafting for periprosthetic bone cysts following total ankle arthroplasty (TAA). Additionally, we evaluated the rate of graft incorporation and identified associated predisposing factors using CT scan. Methods: We reviewed a total of 37 ankles (34 patients) that had undergone bone grafting for periprosthetic bone cysts. A CT scan was performed one year after bone grafting to check the status of graft incorporation. For accurate analysis of cyst volumes and their postoperative changes, 3D-reconstructed CT scan processed with 3D software was used. For functional outcomes, variables such as the Ankle Osteoarthritis Scale score and the visual analogue scale for pain were measured. Results: Out of 37 ankles, graft incorporation was successful in 30 cases. Among the remaining seven cases, four (10.8%) exhibited cyst re-progression, so secondary bone grafting was needed. After secondary bone grafting, no further progression has been noted, resulting in an overall 91.9% success rate (34 of 37) at a mean follow-up period of 47.5 months (24 to 120). The remaining three cases (8.1%) showed implant loosening, so tibiotalocalcaneal arthrodesis was performed. Functional outcomes were also improved after bone grafting in all variables at the latest follow-up (p < 0.05). The mean incorporation rate of the grafts according to the location of the cysts was 84.8% (55.2% to 96.1%) at the medial malleolus, 65.1% (27.6% to 97.1%) at the tibia, and 81.2% (42.8% to 98.7%) at the talus. Smoking was identified as a significant predisposing factor adversely affecting graft incorporation (p = 0.001). Conclusion: Bone grafting for periprosthetic bone cysts following primary TAA is a reliable procedure with a satisfactory success rate and functional outcomes. Regular follow-up, including CT scan, is important for the detection of cyst re-progression to prevent implant loosening after bone grafting.

Do Patients With Insulin-Dependent and Non-Insulin-Dependent Diabetes Have Different Risks for Complications After Total Ankle Arthroplasty?

BACKGROUND: Patients with diabetes undergoing total ankle arthroplasty tend to be at greater risk for complications than those without diabetes. However, the effect of diabetes severity and how it impacts the risk for perioperative complications is less clear. The purpose of this study was to compare (1) complications, (2) length of hospital stay, and (3) readmissions within 30 days for total ankle arthroplasty (TAA) patients without diabetes, patients with non-insulin-dependent diabetes, and patients with insulin-dependent diabetes. METHODS: Using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, a total of 1803 patients undergoing TAA between 2007 and 2019 were collected. The relationship between diabetes status (no diabetes [n = 1,589], insulin-dependent [n = 169], and non-insulin-dependent [n = 45]) and outcomes were compared. Multivariate linear regression models were used to adjust for confounding variables such as age, sex, race, body mass index, smoking, steroid use, hypertension, chronic obstructive pulmonary disease, anesthesia type, dyspnea, and outpatient status. Statistical significance was set at P <.05. RESULTS: Insulin-dependent diabetes was an independent risk factor for increased odds of infection within 30 days (odds ratio 6.47, 95% CI 0.79-33.66; P = .043). Hospital length of stay was also increased in patients with non-insulin-dependent diabetes (ß = 0.21, 95% CI 0.02-0.40; P = .031) and insulin-dependent diabetes (ß = 0.40, 95% CI 0.04-0.76; P = .028). However, neither diabetic state demonstrated a statistically significant increase in readmissions or wound complications within 30 days. CONCLUSION: Patients with insulin-dependent diabetes included in this cohort were at increased risk of having an infection within 30 days after TAA. Additionally, patients with diabetes status had an increased hospital length of stay. These results can inform patients on their potential outcomes after total ankle arthroplasty based on their diabetes status.

The significance of heterotopic ossification following total ankle arthroplasty: a systematic review and meta-analysis.

PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the prevalence and clinical significance of heterotopic ossification (HO) following total ankle replacement (TAR). METHODS: During August 2023, the PubMed, Embase and Cochrane library databases were systematically reviewed to identify clinical studies reporting HO following TAR. Data regarding surgical characteristics, pathological characteristics, subjective clinical outcomes, ankle range of motion, radiographic outcomes, reoperation rates were extracted and analysed. RESULTS: Twenty-seven studies with 2639 patients (2695 ankles) at a weighed mean follow-up time of 52.8 ± 26.9 months were included. The pooled prevalence rate was 44.6% (0.25; 0.66). The implant with the highest rate of HO was the INBONE I (100%) and BOX (100%) implants. The most common modified Brooker staging was grade 1 (132 patients, 27.0%). Random effects models of standardized mean differences found no difference in American orthopedic foot and ankle society (AOFAS) scores, visual analog scale scores (VAS) and ankle range of motion (ROM) between patients with HO and patients without HO. Random effects models of correlation coefficients found no correlation between AOFAS, VAS and ROM and the presence of HO. The surgical intervention rate for symptomatic HO was 4.2%. CONCLUSION: This systematic review and meta-analysis found that HO is a common finding following TAR that is not associated with inferior clinical outcomes. Surgical intervention was required only for moderate-to-severe, symptomatic HO following TAR. This study is limited by the marked heterogeneity and low level and quality of evidence of the included studies. Further higher quality studies are warranted to determine the precise prevalence and impact of HO on outcomes following TAR.

Implant Choice May Reduce the Risk of Early Mechanical Failure in Total Ankle Replacement.

BACKGROUND: Total ankle replacements (TARs) have rapidly advanced in terms of volume, technique, design, and indications. However, TARs are still at risk for early mechanical failure and revision. Prior studies have investigated potential risk factors for failure, but have been limited to smaller series or older implants. This study sought to identify risk factors for early mechanical failure in modern TAR. METHODS: This is a retrospective study of a single-institution registry. Five surgeons contributed cases involving patients who underwent a primary TAR with any implant. Implants were grouped on the basis of the type of fixation. The primary outcome was early mechanical failure (revision with component removal for a non-infectious etiology, that is, subsidence, aseptic loosening, and/or malalignment). Logistic regression determined the effects of age, weight, hindfoot arthrodesis, implant type, and radiographic deformity on failure. RESULTS: The 731 included patients had a mean follow-up of 2.7 years. Ten percent (71 patients) had hindfoot arthrodesis. There were 33 mechanical failures (4.5%) at a mean of 1.7 years after the index surgical procedure. Our model demonstrated that hindfoot arthrodesis was associated with 2.7 times greater odds of failure (p = 0.045), every 10 kg of body weight increased the odds of tibial-sided failure by 1.29 times (p = 0.039), and implants with more extensive tibial fixation (stems or keels) lowered the odds of tibial failure by 95% (p = 0.031). CONCLUSIONS: In patients with uncontrollable risk factors (hindfoot arthrodesis) or risk factors that may or may not be modifiable by the patient (weight), implants with more robust tibial fixation may be able to reduce the risk of early mechanical failure. Further research is warranted to support efforts to decrease early failure in TAR. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Contemporary modern total ankle arthroplasty (TAA): A systematic review and meta-analysis of indications, survivorship and complication rates.

BACKGROUND: This study evaluates the clinical outcomes of contemporary total ankle arthroplasty (TAAs) to primarily establish the current benefits and risks to facilitate informed decision making to secondarily establish if improvements are seen between subsequent generations of implants, bearing philosophy, and associated surgical technique. METHODS: A systematic review and meta-analysis of published data from January 2000 to January 2020 was conducted following PRISMA guidelines. INCLUSION CRITERIA: English language papers, adult population, ≥20 ankles with a minimum follow up ≥24 months, pre- and post-operative functional scores available. Ankle implants were characterised by generations, which were determined from the original studies and confirmed based on literature set definitions. RESULTS: A total of 4642 TAAs in 4487 patients from 51 studies were included. The mean age was 61.9-years and follow up 57.8-months. Overall, 10-year survivorship rates were 77.63 %, with mobile bearing designs showing a small but significant advantage. Improved survivorship favoured the most modern implants at both two (p < 0.05), and 10-years (p < 0.01). The relative risk of a complication occurring improved with the evolution of implants e.g., nerve injury, and post-operative complications such as fracture, wound complications (e.g., dehiscence or heamatoma) and radiological abnormalities (e.g., radiolucencies, heterotopic bone formation and aseptic loosening). However, surgical site infection, and intra-operative fracture rates remain implant independent. CONCLUSIONS: Modern TAA offers improved survivorship, even with a trend to lower mean implantation age, similar complexity and ever changing indications. It would appear that implant evolution has reduced risks, especially those associated with revision, without affecting functional outcomes.

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.

Outcomes of Total Ankle Arthroplasty After Reoperation due to Gutter Impingement.

Gutter impingement is one of the most common causes of subsequent surgery after total ankle arthroplasty (TAA). Although gutter debridement has been reported to resolve preoperative symptoms early on, persistent pain after surgery, recurrence, and poor functional outcome scores have been described in patients who have undergone reoperation for gutter debridement. The cause of gutter impingement after TAA is multifactorial, and a better understanding of its causes and optimal surgical techniques for intervention is needed.

Outcomes of Total Ankle Arthroplasty After Periprosthetic Cyst Curettage and Bone Grafting.

Total ankle arthroplasty (TAA) has become a popular management option for ankle arthritis. Periprosthetic osteolysis is one of the most common causes for reoperation in TAA. A CT scan should be done in all suspected osteolysis cases to confirm location, quantify size and aid in surgical planning. These patients are often asymptomatic with limited evidence regarding appropriate management. Smaller lesions should be monitored for progression in size. Periprosthetic cysts measuring 10-15mm in all three axes should be considered for debridment and curettage with autogenous bone grafting. The authors believe that bone grafting of large asymptomatic periprosthetic cysts could prevent implant failure.

Quality of Outcomes Research in Total Ankle Arthroplasty.

Total ankle arthroplasty is a topic that has recently gained increasing interest, largely due to the improved outcomes, which have been demonstrated by short- and mid-term research studies on the newer, third-generation implant designs. The purpose of this review is to provide an updated assessment of the quality of outcomes research on total ankle arthroplasty.

Clinical Outcomes and Registry Data in Total Ankle Arthroplasty.

Total ankle arthroplasty (TAA) is an effective treatment for end-stage ankle arthritis consistently demonstrating good to excellent outcomes, even when considering factors such as deformity, patient age, bilaterality, and arthritis etiology. There is little consensus in the literature with regard to preferred patient-reported outcome metrics (PROMs) for assessing outcomes, although all metrics generally improve following TAA. Several countries have successful registries to track longevity of TAA in populations; however, PROMs are generally not successfully tracked in registries. A trend toward consensus on outcome metrics and collaborative registries is warranted to optimize patient selection and outcomes in TAA.

Results of Total Ankle Arthroplasty Versus Ankle Arthrodesis.

No differences have been found between total ankle arthroplasty (TAA) and ankle arthrodesis (AA) with respect to patient-reported outcome measures (PROMs), although both interventions were shown to improve PROMs with respect to the preoperative situation. That is, both interventions (AA and TAA) were effective in improving preoperative symptoms. On the other hand, 2-year complication rates were higher after AA (27%) than after TAA (16%); however, infection rates were similar (4%). The published revision rate after AA is 16% versus 11% after TAA. In short, TAA and AA appear to offer the same PROMs, but TAA has a lower rate of complications (except for infection) and revisions.

Diagnosing and Managing Infection in Total Ankle Replacement.

Infections after total ankle replacement (TAR) within the first 4 weeks after implantation can be managed successfully with 1 or several debridements, irrigation, and a change of polyethylene inlay. Late infections require implant removal. Low-grade infections might be an underestimated problem so far. Although single-surgery revisions are reported in the literature, the authors' experience with 2-stage revisions using an antibiotics-loaded bone cement spacer is better. Additional antibiotics are used to support the surgical treatment. After antibiotic therapy of 12 weeks, the final treatment includes ankle or tibio-talo-calcaneal fusion and, with limitations, revision TAR.

Complications in Total Ankle Replacement.

The debate between ankle arthrodesis and total ankle replacement for patients with end-stage arthritis of the ankle joint is an ongoing topic in orthopedic surgery. Ankle arthrodesis, or fusion, has been the traditional treatment for ankle arthritis. It involves fusing the bones of the ankle joint together, eliminating the joint and creating a solid bony union. Arthrodesis is effective in reducing pain in the ankle, but it results in a loss of ankle motion. This can increase the load on adjacent joints, such as the subtalar joint, which may lead to accelerated degeneration and arthritis in those joints over time.

Outcomes of Total Ankle Replacement with Preoperative Varus Deformity.

Historically, coronal plane deformities of greater than 10° to 15° have been deemed contraindications for total ankle replacement (TAR). However, recent studies show satisfactory results in TAR with severe preoperative varus deformity. When correctly applying ancillary procedures, preoperative varus deformity can be structurally corrected, resulting in similar clinical scores to those obtained with "regular TAR." However, complications and revisions appear to increase with increasing deformity. Unfortunately, results of TAR in varus ankles consist of heterogeneous data (eg, with regards to prosthetic brands, bearing-types, duration of follow-up, and ancillary procedures) precluding strict conclusions. This could be solved by an international consensus group.

Outcomes of Conversion of Ankle Fusion to Total Ankle Arthroplasty.

With ankle replacements gaining popularity and documented good functional outcomes, there is an increasing number of patients inquiring about the possibility of converting an ankle fusion to a replacement. This could be due to pain, limited function, or increasing adjacent joint arthritis. There is an increasing body of evidence in the literature that a conversion to a replacement is possible and that the outcomes are positive. There are also absolute contradictions for a conversion. An absent fibula, pain of unknown origin, and recent infection fall in this category. Long-term follow-up is needed to see if conversions of ankle fusions to replacements have the same functional results and longevity as primary replacements.