Outcome Of Total Ankle Replacement Research Articles

Outcomes of total ankle replacement – Current evidence

Total ankle replacement surgery is gaining popularity and is beginning to establish itself as a viable alternative to arthrodesis in the treatment of end-stage ankle arthritis. Only a few studies exist directly comparing these 2 techniques. Also lacking are the long-term outcome studies of ankle replacement surgery. A better understanding of clinical and patient-reported outcome measures after ankle fusion and replacement will enable the surgeon to better counsel the patient and help choose the right treatment. This article will summarise the reported clinical outcomes after total ankle replacements and survivorship analysis from the various national arthroplasty registers.

A Review Study on Total Ankle Replacement

Total ankle replacement (TAR) is the replacement of a damaged arthritic ankle joint with a prosthetic implant to eliminate the source of resultant pain and swelling. Historically, however, the ankle joint has been one of the most difficult joints to analyze and replicate for successful replacement due to its complex anatomy and multiplanar motion. Ankle fusion, the standard of care for end stage ankle arthritis, has excellent functional outcomes but results in loss of motion at the joint. TAR was first attempted in the 1970s and by the early 1990s, prosthesis designs more closely mirrored the natural anatomy of the ankle and TAR was no longer considered an experimental procedure. Although the outcomes of TAR have significantly improved over this short period of time, there are still many areas that warrant further investigation including (1) optimal patient selection, (2) number of prosthesis components, (3) bearing type, (4) revision rates and causes and (5) comprehensive finite element models (FEM) of the ankle. The main goal of this paper is to present a literature review on the background and evolution of TAR, the current state of practice and prosthesis types and challenges and directions for future improvement.

Analysis of Polyethylene-Related Revisions After Total Ankle Replacements Reported in US Food and Drug Administration Medical Device Adverse Event Database.

There are 2 general types of total ankle replacement (TAR) designs with respect to the polyethylene insert, mobile-bearing (MB) and fixed-bearing (FB) TARs. The aim of this study is to compare polyethylene-related adverse events (AEs), particularly revisions, reported for MB TARs and FB TARs using the US Food and Drug Administration's (FDA's) Manufacturer and User Facility Device Experience (MAUDE) database. A text mining method was applied to the medical device reporting (MDR) in the MAUDE database from 1991 to 2020, followed by manual reviews to identify, characterize, and describe all polyethylene-related AEs, including revisions, reported for MB and FB TARs. We found 1841 MDRs for MB (STAR Ankle only) and 1273 MDRs for 40+ FB TARs approved/cleared by the FDA. For the MB design, 33% (606/1841) of the AEs reported related to the polyethylene component, compared to 24% (291/1273) of the AEs reported for FB designs. Polyethylene fractures were reported in 11.3% (208/1841) for the MB designs compared to 0.2% (2/1273) for the FB designs. Half of the polyethylene-related revisions occurred within an average of 4.1 years after implantation for the MB design compared within an average of 5.2 years for FB designs. Analysis of this database revealed a higher proportion of reported polyethylene fractures and greater need for earlier revisions for polyethylene-related issues with use of the primary MB design in the database as compared with FB TAR designs. Further study of device-related complications with more recent designs for both MB and FB ankle replacement components are needed to improve the outcomes of total ankle replacement. Level III, retrospective comparative study.

Early-Term Results of the Cadence Total Ankle Prosthesis: An European Noninventor Study.

Although considerable literature can be found on the outcome of total ankle replacement (TAR), only a few studies have reported the results of the fixed-bearing Cadence prosthesis. This noninventor study reports a consecutive series of 60 Cadence TAR systems with a mean of 2.9 years' follow-up, focusing on clinical and radiographic outcomes and early complications. This study is the first to assess true postoperative radiographic ankle prosthesis range of motion (ROM) and to report an unanticipated serious adverse device effect. Sixty patients who underwent primary TAR with the Cadence prosthesis between July 2016 and July 2019 were clinically and radiographically evaluated preoperatively and at last follow-up after the procedure. Revisions, additional procedures, implant failure, and complications were reported according to the classifications of Vander Griend and Glazebrook. Radiographic outcomes included radiographic TAR ROM, bone-implant interface, and alignment parameters. The survival rate of the prosthesis was 98.3%. The mean radiographic ankle ROM at the last follow-up was 24 degrees (9 degrees of dorsiflexion and 15 degrees of plantarflexion). The coronal and sagittal alignment of TAR was 90.8 degrees and 3.9 degrees, respectively. Bone-implant interface analysis revealed osteolysis in 9 ankles (15%) and radiolucent lines in 33 ankles (55%) occurring at both component interfaces. Intraoperative complications were 3 periprosthetic malleolar fractures (5%). Five talar implant fractures (implant failure of 8.3%) were observed, and 1 unexplained persistent pain that required a conversion from TAR to a tibiotalocalcaneal arthrodesis. Clinical, radiograph ROM, implant position outcomes, and survival rate at an early-term follow-up of 2.9 years were similar to those reported in recent Cadence studies. However, this study reports 5 unanticipated talar implant fractures and a high rate of posterior radiolucent lines. Level IV, retrospective case series.

Total ankle arthroplasty with the use of Zimmer prosthesis and a review of the results of previous research conducted in this field.

The aim of this article is to describe surgical technique and early results of Total Ankle Replacement (TAR) from lateral approach using Zimmer TM prosthesis. The study uses theoretical knowledge which is the result of research conducted by other authors, and practical knowledge due to the fact that our center performs that type of operation. Arthrodesis as the current standard in the treatment of advanced degenerative ankle disease, apart from its advantages, also has many disadvantages. The relative durability and reduction of the patients' pain have been achieved at the expense of the adjacent joints. Their accelerated arthrosis is the result of compensatory loads as a consequence of change in foot biomechanics. That determined implementation of solutions that will guarantee elimination of pain in the ankle joint, preserve its motor function and improve gait, while having no negative impact on the mobility of adjacent joints.

The Effect of Tranexamic Acid on the Outcome of Total Ankle Replacement.

Background: Infection rates after total ankle replacement (TAR) are known to be greater than those after hip or knee arthroplasty. Swelling after TAR can make wound healing more difficult, which can lead to infection. Tranexamic acid (TXA) has been shown to minimize blood loss after surgery, improving healing outcomes. We aim to assess the effect of TXA on blood loss and wound complications in TAR.Methods: The research looked retrospectively at patients who had TAR procedures between September 2014 and December 2019. The procedures were done using the anterior approach at a single hospital by two, foot and ankle surgeons. Tranexamic acid was given intraoperatively before the tourniquet was inflated. The surgeons did not use surgical drains. Pre and postoperative hemoglobin levels, outcome scores as well as post-operative complications were all documented.Results: A total of 69 patients were included in the study with 33 of them receiving TXA. With a mean age of 67.2, we had 31 females and 38 males. Tranexamic acid was given in doses ranging from 1 gm to 2 gm. None of the patients required blood transfusions after surgery, and there was no statistically significant difference in pre and postoperative hemoglobin levels between the two groups. In the TXA group, there were fewer wound complications. The TXA group achieved better results compared to the non-TXA group (p=0.0130).Conclusion: Tranexamic acid is safe and effective in lowering postoperative bleeding and preserving hemostasis after deflating the tourniquet, reducing edema and postoperative wound problems such as breakdown and dehiscence.

10 Year Outcomes of Unilateral vs Bilateral (Staged) Total Ankle Replacement

Category:Ankle Arthritis; AnkleIntroduction/Purpose:Comprehensive long-term outcomes of total ankle replacement (TAR) help guide clinicians when they are deciding on the management of patients with more than single joint arthritis. Some patients will only require unilateral TARs, while others will need bilateral TARs. When deciding on treatment plans for patients, it is important to know the long-term surgical outcomes of both of these groups before treatment can be recommended. Currently there is a paucity of literature on long-term outcomes of unilateral versus bilateral TARs. The aim of the study is to assess long-term outcomes in patients who underwent unilateral vs. staged bilateral TARs.Methods:We performed a retrospective review of a prospectively completed hospital registry database for TAR. This consisted of a consecutive series of TARs performed by one senior surgeon from 2006 to December 2010 with 10-years of follow up. Clinical complications, radiological complications (lucency, cysts, and osteolysis), and patient reported outcome measures (WOMAC score, SF-36, general health survey, and patient satisfaction survey) were included for all patients. Outcomes were evaluated pre-operatively and at 1, 3, 5, and 10 years post-operatively. Three component mobile bearing implants were used in all patients.Results:There were 132 unilateral TARs (Group A) vs. 24 staged bilateral TARs (Group B). WOMAC scores significantly improved from pre-op to 1 year for pain (45.3 to 77.8; 52 to 76) function (49.1 to 77.8; 53.6 to 76) and stiffness (39.8 to 67.9; 55 to 65) in both groups respectively (p<0.05). At 5 years, Group B reported higher function scores than Group A (79.1 vs. 65.7; p=0.05). At 10 years Group B reported significantly better stiffness scores than Group A (78.5 vs. 59.5; p=0.034). There was no significant difference in SF-36 scores between groups at 5 and 10 years. Group A was 40% dissatisfied with return to recreational activities compared to 30% in Group B (p>0.05). Group A reported 16% dissatisfaction with surgery compared to 10% in Group B (p>0.05). At 5 years there were a higher number of radiological and clinical complications in Group A compared to Group B.Conclusion:For patient reported outcomes, staged bilateral TAR patients had more improvement in function at 5 years, and stiffness at 10 years, when compared to unilateral TAR patients. Unilateral TAR patients had higher rates of complications compared to staged bilateral TAR patients at 5 years.A limitation of this study was the smaller size of Group B patients compared to Group A. We will be able to present a detailed breakdown of outcomes at each time point if the abstract is selected for presentation.

Does Sagittal Tibiotalar Alignment of TAR Predict Failure?

Category:Ankle ArthritisIntroduction/Purpose:The long term outcome of total ankle replacement is contingent on restoring the anatomic tibiotalar alignment of the ankle joint. Prior studies have mainly looked at the effect of coronal and hindfoot alignment of TAR on outcome and failure with few studies focusing on the effect of sagittal tibiotalar alignment. From these, we know that sagittal alignment has a greater impact on joint mechanics and that proper positioning of the talar component in the sagittal plane results in greater postoperative pain relief and better functional outcome, especially ankle range of motion. The goal of this study was to define a sagittal radiographic value that predicts failure in TAR.Methods:We analyzed the data of a retrospective patient cohort of consecutive TAR patients, which were treated from 2004 and 2011. Patients with two types of prosthesis were included, Salto Talaris (fixed bearing) and STAR (mobile bearing). All measurements were completed by two blinded observers, including the sagittal distal tibial articular angle (sDTAA), the lateral talar station (LTS) and the talar component inclination angle (γ angle). A total of 90 patients were included, 51 were male and 39 female patients. Seventy-seven patients received a Salto and 13 patients a STAR prosthesis. The average age was 63.7 years.Results:The mean sDTAA was 83.9 degrees and the mean γ angle was 21 degrees, both without significant difference in the two different prosthesis designs. A significant association (p=0.03) between post-op LTS as a continuous variable per unit increase and clinical failure was demonstrated, which included all the revision cases, with an odds ratio of 1.25. In addition a significant association (p=0.03) between increased LTS and sDTAA change of >5°, which is indicative of anterior subsidence, was shown. This was associated with an odds ratio of clinical TAR failure of 1.27.Conclusion:The abnormal radiographic post-op lateral talar station appears to predict clinical TAR failure and correlates with the abnormal sDTAA; the anterior translated talus loads the anterior tibia leading to anterior subsidence of the prosthesis. Limitation of this study is the inclusion of two different types of prosthesis designs.

Total Ankle Arthroplasty Outcome in Patients with Inflammatory vs Non-Inflammatory Arthritis: Systematic Review and Meta-Analysis

Category:Ankle; Ankle ArthritisIntroduction/Purpose:The decision regarding total ankle replacement is challenging in inflammatory arthritis patients regarding more inferior bone quality, large bone cysts, and increased risk for infections. This systematic review aimed to compare the short and long-term results of total ankle replacement, including the revision rate and the patient-reported outcomes between inflammatory rheumatoid arthritis (RA) versus non-inflammatory ankle osteoarthritis (OA).Methods:All published clinical studies on total ankle arthroplasty were searched in the databases. We extracted the data, specifically the American Orthopaedic Foot & Ankle Society (AOFAS) improvement, complication rate, and the reoperation rate. The results were also analyzed based on the prosthesis type.Results:In total, 34 trials were included in our study. Out of 5,078 patients, the underlying condition was rheumatoid arthritis in 1,327 patients and was non-inflammatory osteoarthritis in 2,849 patients. There was statistically significant higher AOFAS improvement in the patients with RA vs. OA with a mean follow-up of 63 months (P=0.009). The rates of TAA removal or revision were estimated at 16% (95% CI, 10%-23%) in the OA and 13% (95% CI, 9%-18%) in the RA group. Overlapping confidence intervals showed no significant difference in the rate of failure between RA and OA. The survival rate was 66% in the OA group and 88% in the RA group during a 63-month follow-up.Conclusion:Total ankle replacement is a safe procedure in RA patients with fewer minor and major complications relative to other reasons for ankle osteoarthritis.

Revision Rates After Total Ankle Replacement: A Comparison of Clinical Studies and Arthroplasty Registers.

The aim of this study was to assess the outcome of total ankle replacement (TAR) regarding revision rates by comparing clinical studies of the last decade to data displayed in arthroplasty registers. The secondary aim was to evaluate whether dependent clinical studies show a superior outcome to independent publications. Additionally, revision rates of mobile bearing implants (MB-TARs) were compared to those of fixed bearing implants (FB-TARs). Clinical studies on TARs between 2010 and 2020 were systematically reviewed, with the endpoint being a revision for any reason. The parameter "revision rate per 100 observed component years (CYs)" was calculated for each publication. The pooled revision rate for clinical studies was compared to the data reported in arthroplasty registers. In a second step, revision rates were subdivided and analyzed for independent and dependent publications and for FB-TARs and MB-TARs. A total of 43 publications met the inclusion criteria comprising 5806 TARs. A revision rate of 1.8 per 100 observed CYs was calculated, corresponding to a 7-year revision rate of 12.6%. The 3 arthroplasty registers included showed revision rates ranging from 8.2% to 12.3% after 7 years. No significant difference between dependent and independent publications nor between FB-TARs and MB-TARs was detected. Revision rates of clinical studies and arthroplasty registers are comparable. Surgeons can compare their own revision rates with those from this study. Dependent studies do not seem to be biased, and no superiority for one bearing type can be described. Level III, systematic review of level III studies.

Mid-Term Functional and Radiological Outcomes of Total Ankle Replacement in an Asian Cohort

There are limited studies looking at longer-term outcomes of the total ankle replacement (TAR) in the Asian cohort. Asian ankles are smaller in size and are more varus compared to Western cohorts. Cultural differences also require increased ankle range of motion demands. Therefore, assessment of longer-term functional and radiological outcomes in the Asian cohort is warranted. Between 2007 and 2015, 43 consecutive patients received a 3-component, cementless, unconstrained, fully congruent TAR. Patients were followed up over a mean 8 (range 5-14 years). Preoperative and postoperative AOFAS ankle-hindfoot score (AOFAS-AHS), visual analogue score (VAS), physical and mental component scores of the SF-36 (PCS and MCS respectively) were calculated. European Foot and Ankle Score was also recorded at 8 years. Radiographs were reviewed postoperatively to assess implant position and study evidence of implant loosening and impingement. At 8 years, survivorship was 83.5%. Reasons for implant removal included infection (n = 2) and aseptic loosening (n = 5). AOFAS-AHS, VAS MCS at 8 years postoperatively were comparable to outcomes at 2 years postoperatively (p > .05). PCS at 8 years demonstrated improvement compared to 2 years postoperatively (49 ± 7 vs 42 ± 11, p = .048). Radiographic impingement was noted in 9 cases (20.9%). Radiological loosening was noted in 8 cases with 5 cases requiring revision surgery. At 8 years postoperatively, clinical outcomes, radiological outcomes and survivorship following TAR in an Asian cohort are satisfactory and comparable to that found in existing literature. Long-term studies are required to ascertain survivorship of TAR. Implant design with the Asian cohort in mind may yield improved outcomes.

Effect of artificial surface shapes and their malpositioning on the mechanics of the replaced ankle joint for possible better prosthesis designs

BackgroundThe clinical outcomes of total ankle replacement are limited by prosthesis component malpositioning during surgery. The goal of this study is to assess the mechanical impact of this malpositioning in a validated computer model. MethodsIn a previously developed multi-body dynamic model of the human ankle complex three different artificial implants were designed, each one presenting a different approximation of the natural articular surfaces of the corresponding specimen. The most common implant translational and rotational malpositionings were defined and mimicked. Dynamic simulations of joint motion were run for the various surfaces and malpositionings. The same input loading conditions derived from a previous in-vitro experiment on the corresponding natural specimen were applied. FindingsFrom load-displacement graphs it was observed that all three artificial surfaces reproduced well physiological motion between the calcaneus and the tibia/fibula, with a maximum difference of 2°. It was found that antero-posterior translation of either the tibial or the talar component and inclination of the tibial component in the sagittal plane led to considerable increases in the range of motion. Antero-posterior and dorsiflexion of the tibial component resulted in an increased internal-external rotation by up to 3.5° and 4.0°, respectively. The corresponding increase of inversion-eversion was 5.0° and 6.5°. InterpretationThis study showed that relatively small surgical errors have great consequences in replaced joint mechanics. The present model can be used in future studies to analyse the effect of malpositioning with any specific current total ankle prosthesis.

Total Joint Replacement of Ankle, Knee, and Hip: How Do Patients Perceive Their Operative Outcomes at 10 Years?

Background:Patient-reported outcomes (PROMs) are an integral part of national joint registers in measuring outcomes of operative procedures and improving quality of care. There is lack of literature comparing outcomes of total ankle replacement (TAR) to total knee replacement (TKR) and total hip replacement (THR). The aim of this study was to compare PROMs between TAR, TKR, and THR patient groups at 1, 5, and 10 years.Methods:Prospective PROMs from patients who underwent a TAR, TKR, or THR procedure between 2003 and 2010 were studied. Patients were divided into 3 groups based on their index joint replacement (hip, knee, or ankle). Patient demographics (age, gender, body mass index), patient-reported outcome scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], 36-Item Short Form Health Survey [SF-36]) and patient satisfaction scores (4-point Likert scale) at follow-up were compared between the 3 groups.Results:Data was available on 1797 THR, 2475 TKR, and 146 TAR patients. TAR patients were younger and reported fewer number of comorbidities. All 3 groups improved significantly from preoperative to 10 years for WOMAC scores (P < .001). For SF-36 scores at 10 years, the THR group (32.2% follow-up) scored the highest for 3 domains (P = .031) when compared to the TKR group (29.1% follow-up). All 3 groups had similar outcomes for 5 of 8 domains; P < .05). For patient satisfaction, the THR group reported overall 95.1% satisfaction followed by 89.8% for the TKR group and 83.9% in the TAR group (42.4% follow-up).Conclusion:In this cohort with diminishing numbers over the decade of time the patients were followed up we found that patients are equally happy with functional and general health outcomes from total ankle replacement vs other major lower extremity joint replacement. TAR surgery should be considered as a viable treatment option in this patient group.Level of Evidence:Level III, retrospective case series.

Adverse events related to total ankle replacement devices: an analysis of reports to the United States Food and Drug Administration

BackgroundThe published outcomes of total ankle replacement (TAR) implants came from limited institutions creating observational bias. For broader perspective, we queried the Food and Drug Administration’s (FDA) Manufacturer and User Facility Device Experience (MAUDE) voluntary database to explore complications reported outside published literature.MethodsThe database was reviewed retrospectively between November 2011 and April 2019 using two product codes assigned to six TAR devices.ResultsAmong 648 relevant reports available in the database, common complications were aseptic loosening (19.3%), infection (18.2%), and alignment/mechanical issues (16.5%). Others included instrument/instrumentation complications, impingement, polyethylene problems, fractures, avascular necrosis of talus (AVN), and packaging issues.ConclusionMAUDE database revealed various patterns of device-related malfunctions that have been under-reported in published data. Despite inconsistency in the available reports, it provided opportunities for improvements in quality control, device design, and ultimately patient safety. Database would be further strengthened by more robust reporting mechanism or mandatory reporting of device-related complications.

Clinical outcome results of total ankle replacement and ankle arthrodesis: a pilot randomised controlled trial

BackgroundAnkle arthrodesis (AA) and replacement (TAA) are widely accepted options in managing end-stage ankle arthritis (ESAA). We hypothesize that clinical outcomes would be similar for both interventions. MethodsWe conducted a multicenter randomized controlled trial that collected data on patient demographics, complication rates, Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36) scores. We evaluated pre and postoperative scores within and between cohorts. ResultsThe thirty-nine ankles enrolled had a mean follow-up of 5.1 ± 2.8 years. Total AOS scores improved significantly in both groups; 59.4 ± 15.9 to 38 ± 20 (p-value = 0.002) for TAA and 64.6 ± 19.7 to 31.8 ± 16.5 (p-value < 0.001) for AA at last follow-up. Complication rate was higher in the AA cohort with four major complications (20%). ConclusionWe observed a statistically significant benefit with TAA and AA. As a pilot trial, this study is meant to inform on design and feasibility of future RCTs. Level of evidenceII

Trends in Total Ankle Replacement in Scotland

Category:Ankle ArthritisIntroduction/Purpose:Total ankle replacement (TAR) is performed for post-traumatic arthritis, inflammatory arthropathy, osteoarthritis and other indications. The Scottish Arthroplasty Project (SAP) began collection of data on TAR in 1997. In this study, using data from the SAP, we look at trends in the use and outcomes of TAR in Scotland.Methods:We identified 499 patients from the SAP who underwent TAR between 1997 and 2015 with imaging available on the National Picture Archiving and Communication System (PACS). We identified, and looked at trends in, implant type over the following time periods: 1998-2005; 2006-2010 and 2011-2015. Age, gender, indication and outcomes for each time period were examined and also trends with implant type over time.Results:There were 499 primary TAR procedures with an overall incidence of 0.5/105 population per year. The peak incidence of TAR was in the 6th decade. The mean age of patients undergoing TAR from 59 years in 1998-2005, to 65 years in 2011-15 (p<0.0001). The percentage of patients with inflammatory arthropathy was 49% in 1998-2005, compared with 10% in 2011-2015. Subsequent arthrodesis and infection rates appeared to be higher during the first time period. The female to male ratio also changed over time. The incidence of TAR increased overall during the study period (r= 0.9, p=<0.0001). This may be due to a broadening range of indications and patient selection criteria, in turn due to increased surgeon experience and the evolution of implant design.Conclusion:This study examines a large number of TARs from an established national arthroplasty database. The rate of TAR has increased significantly in Scotland from 1997 to 2015. Indication and patient age has changed over time and this could potentially impact outcomes after ankle replacement.

Two-Year Outcomes of Total Ankle Replacement with the Cadence Total Ankle Replacement System

Category:Ankle, Ankle ArthritisIntroduction/Purpose:Over the last few decades, total ankle replacement (TAR) emerged as a reliable treatment option in end-stage ankle osteoarthritis (OA) while preserving motion and physiological load. The Cadence™ prosthesis, manufactured by Integra LifeSciences, is a two-component, fixed-bearing implant with minimal tibial and talar resection and has been in clinical use since June 2016. The purpose of this study is to assess the two-year validated clinical outcome scores and radiological parameters of the Cadence™ prosthesis at our hospital.Methods:Thirty-one consecutive patients who received the Cadence™ prosthesis between June 2016 and December 31st, 2016 were enrolled. All patients who underwent a primary TAR with the Cadence™ prosthesis and who had at least two years follow- up were included. All surgeries were performed by a single surgeon with experience in total ankle arthroplasty. At the yearly clinical evaluation, patients were administered the Ankle Osteoarthritis Scale (AOS) and the Short Form Health Survey (SF-36), and their radiological outcomes pre and post-surgery were assessed.Results:Thirty-one patients fulfilled the inclusion criteria. Forty ancillary procedures were performed on twenty-four TAR’s. Radiological analyses showed preoperative talar sagittal translation with 25 anterior, 2 posterior, and 4 neutral. Sagittal translation decreased from an average 3.11 mm to 1.0 mm. Eleven ankles had a perioperative talar Varus and Valgus deformity that was corrected, with neutral alignment in all. At the two-year clinic visit, x-rays showed no lucencies or stress fractures and none of the ankles required revision of metal components. The pre and post-operative pain and disability scores displayed major improvement wherein AOS pain scores decreased -20.28 ± 14.34 points from an average of 47.86 points while AOS disability scores decreased -32.11 ± 22.70 from an average of 57.15 points.Conclusion:The overall outcome of the total ankle arthroplasty with the Cadence™ prosthesis showed excellent clinical and radiological outcomes. Compelling clinical evidence shows that the quality of life, functional measures, and pain in patients suffering from end-stage arthritis significantly improved following surgery with the Cadence™ total ankle replacement system. The semi- constrained design of this two-component implant and utilization of biased polyethylene inserts allowed for correction of the talus in both the sagittal (talar anterior / posterior translation) and coronal planes (talar varus / valgus).

Prospective Randomized Trial Comparing Mobile-bearing and Fixed-bearing Total Ankle Replacement

Category: Ankle Arthritis Introduction/Purpose: Outcomes of total ankle replacement for the treatment of end-stage ankle arthritis continue to improve. Debate continues whether a mobile-bearing total ankle replacement (MB-TAR) or a fixed-bearing total ankle replacement (FB-TAR) is superior, with successful outcomes reported longterm for MB-TAR and at intermediate-to-longterm follow-up for newer generation FB-TAR. Although comparisons between the two total ankle designs have been reported, to our knowledge, no investigation has compared the two designs with a high level of evidence. This prospective, randomized controlled trial conducted at a single institution compares patient satisfaction, functional outcomes and radiographic results of the mobile-bearing STAR and the fixed-bearing Salto-Talaris in the treatment of end-stage ankle arthritis. Methods: This investigation was approved by our institution’s IRB committee. Between November 2011 and November 2014, adult patients with end-stage ankle osteoarthritis failing nonoperative treatment were introduced to the study. With informed consent, 100 patients (31 male and 69 female, average age 65, range 35 to 85) were enrolled; demographic comparison between the two cohorts was similar. Exclusion criteria included inflammatory arthropathy, neuropathy, weight exceeding 250 pounds, radiographic coronal plane deformity greater than 15 degrees or extensive talar dome wear pattern (“flat top talus”). Prospective patient-reported outcomes, physical exam and standardized weightbearing ankle radiographs were obtained preoperatively, at 6 and 12 months postoperatively, and then at yearly intervals. Data collection included visual analog pain score (VAS), short form 36 (SF-36), foot and ankle disability index (FADI), short musculoskeletal functional assessment (SMFA) and AOFAS ankle-hindfoot score. Surgeries were performed by non-design team orthopaedic foot and ankle specialists with total ankle replacement expertise. Statistically analysis was performed by a qualified statistician. Results: At average follow-up of 4.5 years (range 2-6 years) complete clinical data and radiographs were available for 84 patients; 7 had incomplete data, one had died, 4 were withdrawn after enrolling but prior to surgery and 4 were lost to follow-up. In all outcome measures, the entire cohort demonstrated statistically significant improvements from preoperative evaluation to most recent follow-up. There was no statistically significant difference in improvement in clinical outcomes between the two groups. Radiographically, tibial lucency/cyst formation was 26.8% and 20.9% for MB-TAR and FB-TAR, respectively. Tibial settling/subsidence occurred in 7.3% of MB-TAR. Talar lucency/cyst formation occurred in 24.3% and 2.0% of MB-TAR and FB-TAR, respectively. Talar subsidence was observed in 21.9% and 2.0% of MB-TAR and FB-TAR, respectively. Re-operations were performed in 8 MB-TAR and 3 FB-TAR, with the majority of procedures being to relieve impingement or treat cysts and not to revise or remove metal implants. Conclusion: For the first time, with a high level of evidence, our study confirms that patient reported and clinical outcomes are favorable for both designs and that there is no significant difference in clinical improvement between the two implants. The incidence of lucency/cyst formation was similar for MB-TAR and FB-TAR for the tibial component, but the MB-TAR had greater talar lucency/cyst formation and tibial and talar subsidence. As has been suggested in previous studies, clinical outcomes do not correlate with radiographic findings. Re-operations were more common for MB-TAR and in the majority of cases were to relieve impingement or treat cysts rather than revise or remove metal implants.

Effect of Type 1 and Type 2 Diabetes Mellitus on Complication and Reoperation Rates of Ankle Arthrodesis and Total Ankle Arthroplasty

Category: Diabetes Introduction/Purpose: Diabetes mellitus (DM) poses a risk for increased rate of complications in many orthopaedic procedures, especially in patients undergoing elective arthroplasty procedures. Treatment of end-stage ankle arthritis includes both arthroplasty and arthrodesis. Current literature provides minimal guidance regarding outcomes of total ankle replacement (TAR) or ankle arthrodesis (AA) in diabetic patients. The authors of this study utilized a large database to compare rates of postoperative complications and reoperations of diabetic patients undergoing surgical management of ankle arthritis to rates seen in non-diabetic patients. Methods: Using the PearlDiver Technologies, Inc. database, Medicare patients diagnosed with ankle arthritis using ICD-9 codes were identified from 2005 to 2014. Patients were then sorted as diabetic or non-diabetic. Diabetic patients were then further stratified into Type 1 diabetes (T1DM) and Type 2 diabetes (T2DM). Type 2 diabetics requiring insulin (T2ID) and not requiring insulin (T2NID) were also isolated. Patients were identified who underwent either AA or TAR utilizing ICD-9 procedure and CPT codes. These groups were evaluated for postoperative complications and reoperation rates. Chi-Squared testing was used to determine significance. Multivariate analysis was performed to determine whether diabetes represents an independent risk factor. Results: 1477 diabetic patients underwent TAR and 5399 underwent AA versus 3900 TAR and 7838 AA in nondiabetics. Diabetics undergoing AA experienced complications at 32.2%, reoperations at 30.8%, and revisions at 18.7% versus 13.3%, 22.3%, and 19.2% respectively in patients without diabetes(P&lt;0.05). In diabetics undergoing TAR, the complication rate was 21.6% and reoperation rates were 16.9% versus 12.5% and 13% respectively in their non-diabetic counterparts(P&lt;0.05). Revision rates were similar. Patients with T1DM had more reoperations and complications in both TAR and AA compared to those with T2DM (P&lt;0.05). In both surgical groups, Patients with T2ID had more complications and reoperations than those with T2NID(P&lt;0.05). Multivariate analysis revealed diabetes as an independent risk factor for complication and reoperation in AA but only complication in TAR(P &lt;0.05). Conclusion: Patients with a diagnosis of diabetes mellitus experienced higher complication and total reoperation rates when undergoing either TAR or AA. T1DM appears to impart a greater risk of surgical complication and repeat surgical intervention than does T2DM. However when insulin is required in T2DM, complication and reoperation rates are similar to those of T1DM. Patient selection for surgical management of end-stage ankle arthritis should incorporate diabetic type and insulin dependency when considering surgical intervention.

An Update on the Canadian Experience Treating End Stage Ankle Arthritis with Fusion or Replacement Surgery

Category: Ankle Arthritis Introduction/Purpose: There is much interest in the surgical treatment of end-stage ankle arthritis. Our team has previously reported comparisons between ankle fusion and replacement outcomes for 321 ankles at 5.5 years from a prospective cohort. This research extends the observational period for another six years, ending in 2013. Our primary hypothesis is that patient-reported clinical outcomes for ankle fusion and replacements would be similar at last follow up. Methods: Patients in the Canadian Orthopaedic Foot and Ankle Society (COFAS) Prospective Ankle Reconstructive Database were treated with total ankle replacement (involving Agilty, Star, Mobilty, Hintegra, or Inbone) or fusion (open or arthroscopic). Patient characteristics collected included demographics, comorbidities, smoking status and body mass index. Patient-reported outcomes (PROs) completed by patients were the Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36). Pre-operative and most recent patient data, with at least four years follow-up, were analyzed. Sensitivity analyses excluded ankles that had undergone revision. A linear mixed-effects regression model compared scores between total ankle replacement and fusion groups, adjusting for patient characteristics, baseline data and surgeon. Results: The sample included 844 ankles (556 ankle replacements and 284 arthrodesis). The mean follow up period was 8.0 years (standard deviation 3.1 years), with minimum and maximum of 4 and 14 years, respectively. Patients treated with arthrodesis were younger, more likely to be diabetic and smokers, and somewhat less likely to have inflammatory arthritis. Overall, 19.4% of ankle fusion and 30.8% of ankle replacements underwent all-cause re-operation. The mean AOS total score improved from 58.6 points pre-operatively to 31.4 post-operatively (delta 27.2), and from 57.0 to 26.9 points (delta 30.1) in the ankle replacement group. Differences in the change in AOS and SF-36 scores between the arthrodesis and ankle replacement groups were minimal after adjustment for baseline characteristics and surgeon. Conclusion: Clinical outcomes of total ankle replacement and ankle arthrodesis were comparable in a diverse cohort of patients whose follow up period ranged between 4 and 14 years post-operatively.