Shape Approximation and Size Difference of the Upper Part of the Talus: Implication for Implant Design of the Talar Component for Total Ankle Replacement

The implant design of the talar component for total ankle replacement (TAR) should match the surface morphology of the talus so that the replaced ankle can restore the natural motion of the tibiotalar joint and may reduce postoperative complications. The purpose of this study was to introduce a new 3D fitting method (the two-sphere fitting method of the talar trochlea with three fitting resection planes) to approximate the shape of the upper part of the talus for the Chinese population. 90 models of the tali from CT images of healthy volunteers were used in this study. Geometrical fitting and morphological measurements were performed for the surface morphology of the upper part of the talus. The accuracy of the two-sphere fitting method of the talar trochlea was assessed by a comparison of previously reported data. Parameters of the fitting geometries with different sizes were recorded and compared. Results showed that compared with previously reported one-sphere, cylinder, and bitruncated cone fitting methods, the two-sphere fitting method presented the smallest maximum distance difference, indicating that talar trochlea can be approximated well as two spheres. The radius of the medial fitting sphere R M was 20.69 ± 2.19 mm which was significantly smaller than the radius of the lateral fitting sphere R L of 21.32 ± 1.88 mm. After grouping all data by the average radius of fitting spheres, the result showed that different sizes of the upper part of the talus presented significantly different parameters except the orientation of the lateral cutting plane, indicating that the orientation of the lateral cutting plane may keep consistent for all upper part of the talus and have no relationship with the size. The linear regression analyses demonstrated a weak correlation ( R 2 < 0.5 ) between the majority of parameters and the average radius of the fitting spheres. Therefore, different sizes of the upper part of the talus presented unique morphological features, and the design of different sizes of talar components for TAR should consider the size-specific characteristics of the talus. The parameters measured in this study provided a further understanding of the talus and can guide the design of different sizes of the talar components of the TAR implant.

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Finite-element analysis of the influence of tibial implant fixation design of total ankle replacement on bone–implant interfacial biomechanical performance

Journal of Orthopaedic Surgery ◽

10.1177/2309499020966125 ◽

2020 ◽

Vol 28 (3) ◽

pp. 230949902096612

Author(s):

Jian Yu ◽

Chao Zhang ◽

Wen-Ming Chen ◽

Dahang Zhao ◽

Pengfei chu ◽

...

Keyword(s):

Finite Element ◽

Total Ankle Replacement ◽

Implant Design ◽

Fixation Method ◽

Implant Loosening ◽

Implant Fixation ◽

Bone Resection ◽

Bone Implant ◽

Initial Stability ◽

Ankle Replacement

Purpose: Implant loosening in tibia after primary total ankle replacement (TAR) is one of the common postoperative problems in TAR. Innovations in implant structure design may ideally reduce micromotion at the bone–implant interface and enhance the bone-implant fixation and initial stability, thus eventually prevents long-term implant loosening. This study aimed to investigate (1) biomechanical characteristics at the bone–implant interface and (2) the influence of design features, such as radius, height, and length. Methods: A total of 101 finite-element models were created based on four commercially available implants. The models predicted micromotion at the bone–implant interface, and we investigated the impact of structural parameters, such as radius, length, and height. Results: Our results suggested that stem-type implants generally required the highest volume of bone resection before implantation, while peg-type implants required the lowest. Compared with central fixation features (stem and keel), peripherally distributed geometries (bar and peg) were associated with lower initial micromotions. The initial stability of all types of implant design can be optimized by decreasing fixation size, such as reducing the radius of the bars and pegs and lowering the height. Conclusion: Peg-type tibial implant design may be a promising fixation method, which is required with a minimum bone resection volume and yielded minimum micromotion under an extreme axial loading scenario. Present models can serve as a useful platform to build upon to help physicians or engineers when making incremental improvements related to implant design.

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Nottingham Experience with The Fixed Bearing Infinity Total Ankle Replacement

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00424 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0042

Author(s):

Hatem Salem-Saqer ◽

Martin Raglan ◽

Sunil Dhar

Keyword(s):

Complication Rate ◽

Weight Bearing ◽

Total Ankle Replacement ◽

Total Ankle Arthroplasty ◽

Implant Design ◽

Fixed Bearing ◽

Ankle Arthroplasty ◽

Ankle Replacement ◽

End Stage

Category: Ankle; Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) is increasingly used for treatment of end stage arthritis of the ankle; improvements continue to evolve in implant design and instrumentation. We present our experience of the Infinity Total Ankle Arthroplasty (Wright Medical), a fixed bearing 4th generation implant with improved instrumentation Methods: This is a retrospective review of prospectively collected data. From October 2016 to July 2019, we identified 92 (52M/40F) who had the infinity Total Ankle Replacement. This review is of 70 patients with a minimum of 1 year follow up (33M,37F). The mean age was 67.5 years (33-87); 32 right side and 38 left no bilaterals. The indication for surgery was end stage Osteoarthritis in 52, post traumatic arthritis 12, inflammatory arthritis 4, conversion of fusion to TAR 2. The preoperative deformity was graded according to the COFAS classification. All patients had follow up at 6 weeks, 3,6 and 12 months and then annually, with MOXFQ questionnaire and weight bearing radiographs. Results: TAA was performed with the use of fluoroscopy. 77% (54/70) had concomitant procedures as listed in Table.5% (4/70) had complications consisting of, 1 DVT, 1 intra operative medial malleolus fracture, 1 EHL tendon laceration and 1 wound break down. There were no deep or superficial infections. Improvement in clinical outcome and PROMS data was noted on follow up. The MOXFQ for Pain improved from 72 pre-op to 25 at 1year (p<0.001). The outcome for Walking improved from 83 pre-op to 30 at one year (p<0.001). Radiological alignment was maintained asymptomatic posterior heterotopic ossification was noted in 23(16%) patients, lucent lines under the tibial implant were noted in 4 ankles and 1 fibula erosion. 2 TAA (3%) needed to be revised due to malpositioning. Conclusion: Our results show significant improvement in patient outcomes, a short recovery time and marked improvement in mobility post operatively with a very low complication rate, we had no deep infection to date. Two implants were revised which we attribute to the learning curve at the start of practice. This implant is fluoroscopically navigated allowing precise implantation with dedicated instrumentation and we feel this attributed to the low complication rate and good results in our short-term study [Table: see text]

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Trends in Total Ankle Replacement in Scotland

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00240 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0024

Author(s):

Taegyeong T. Ha ◽

Chinnasamy Senthil Kumar ◽

Taegyeong T. Ha ◽

Zoe Higgs ◽

Chris Watling ◽

...

Keyword(s):

Total Ankle Replacement ◽

Implant Design ◽

Time Period ◽

Ankle Replacement ◽

Inflammatory Arthropathy ◽

Surgeon Experience ◽

Picture Archiving And Communication ◽

Patient Selection Criteria ◽

Using Data ◽

Over Time

Category: Ankle Arthritis Introduction/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.

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Two Year Follow up of Cadence Total Ankle Replacement

Case Medical Research ◽

10.31525/ct1-nct03866642 ◽

2019 ◽

Author(s):

Keyword(s):

Total Ankle Replacement ◽

Ankle Replacement

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Living With Both a Total Ankle Replacement and an Ankle Fusion: A Qualitative Study From the Patients’ Perspective

Foot & Ankle International ◽

10.1177/10711007211004447 ◽

2021 ◽

pp. 107110072110044

Author(s):

Catherine Conlin ◽

Ryan M. Khan ◽

Ian Wilson ◽

Timothy R. Daniels ◽

Mansur Halai ◽

...

Keyword(s):

Hospital Setting ◽

Case Series ◽

Total Ankle Replacement ◽

Qualitative Description ◽

Level Of Evidence ◽

Foot Placement ◽

Advantages And Disadvantages ◽

Ankle Fusion ◽

Ankle Replacement ◽

Patient Reported

Background: Total ankle replacement (TAR) and ankle fusion are effective treatments for end-stage ankle arthritis. Comparative studies elucidate differences in treatment outcomes; however, the literature lacks evidence demonstrating what outcomes are important to patients. The purpose of this study was to investigate patients’ experiences of living with both a TAR and ankle fusion. Methods: This research study used qualitative description. Individuals were selected from a cohort of patients with TAR and/or ankle fusion (n = 1254). Eligible patients were English speaking with a TAR and contralateral ankle fusion, and a minimum of 1 year since their most recent ankle reconstruction. Surgeries were performed by a single experienced surgeon, and semistructured interviews were conducted by a single researcher in a private hospital setting or by telephone. Ankle Osteoarthritis Scale (AOS) scores, radiographs, and ancillary surgical procedures were collected to characterize patients. Themes were derived through qualitative data analysis. Results: Ten adults (8 men, 2 women), ages 59 to 90 years, were included. Average AOS pain and disability scores were similar for both surgeries for most patients. Participants discussed perceptions of each reconstructed ankle. Ankle fusions were considered stable and strong, but also stiff and compromising balance. TARs were considered flexible and more like a “normal ankle,” though patients expressed concerns about their TAR “turning” on uneven ground. Individuals applied this knowledge to facilitate movement, particularly during a first step and transitioning between positions. They described the need for careful foot placement and attention to the environment to avoid potential challenges. Conclusion: This study provides insight into the experiences of individuals living with a TAR and ankle fusion. In this unusual but limited group of patients, we found that each ankle reconstruction was generally perceived to have different characteristics, advantages, and disadvantages. Most participants articulated a preference for their TAR. These findings can help clinicians better counsel patients on expectations after TAR and ankle fusion, and improve patient-reported outcome measures by better capturing meaningful outcomes for patients. Level of Evidence: Level IV, case series.

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Total Ankle Arthroplasty Survivorship, Complication, and Revision Rates in Patients Younger Than 55 Years

Foot & Ankle Specialist ◽

10.1177/1938640020980925 ◽

2021 ◽

pp. 193864002098092

Author(s):

Devon W. Consul ◽

Anson Chu ◽

Travis M. Langan ◽

Christopher F. Hyer ◽

Gregory Berlet

Keyword(s):

Case Series ◽

Ankle Arthrodesis ◽

Total Ankle Replacement ◽

Implant Survival ◽

Ankle Arthritis ◽

Single Institution ◽

Retrospective Case ◽

Ankle Replacement ◽

End Stage

Total ankle replacement has become a viable alternative to ankle arthrodesis in the surgical management of advanced ankle arthritis. Total ankle replacement has generally been reserved for patients who are older and for those who will have a lower demand on the replacement. The purpose of the current study is to review patient outcomes, complications, and implant survival in patients younger than 55 years who underwent total ankle replacement at a single institution. A single-center chart and radiographic review was performed of consecutive patients who underwent total ankle replacement for treatment of end-stage ankle arthritis. All surgeries were performed by 1 of 5 fellowship-trained foot and ankle surgeons at a single institution. A total of 51 patients met inclusion criteria with a mean follow-up of 31.2 months (SD = 16.2). Implant survival was 94%, There were 7 major complications (13%) requiring an unplanned return to the operating room and 8 minor complications (15%) that resolved with conservative care. The results of this study show that total ankle replacement is a viable treatment option for patients younger than 55 years. Levels of Evidence: A retrospective case series

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Adverse Events in Total Ankle Arthroplasty, Analysis of the FDA Medical and User Facility Device Experience Database

Foot & Ankle Orthopaedics ◽

10.1177/2473011419s00285 ◽

2019 ◽

Vol 4 (4) ◽

pp. 2473011419S0028

Author(s):

Karim Mahmoud ◽

Sreenivasulu Metikala ◽

Kathryn O’Connor ◽

Daniel Farber

Keyword(s):

Adverse Events ◽

Aseptic Loosening ◽

Mandatory Reporting ◽

Total Ankle Replacement ◽

Total Ankle Arthroplasty ◽

Ankle Arthritis ◽

Ankle Arthroplasty ◽

Ankle Replacement ◽

Mode Of Failure ◽

User Facility

Category: Ankle Arthritis Introduction/Purpose: Total ankle replacement has become a popular treatment option for end stage ankle arthritis. Most of the reports of adverse events following total ankle replacement have been from high volume institutions and are subject to either observational or selection bias as well as potential under-reporting as they do not include the experience of community and lower volume centers and surgeons. The FDA’s Medical and User Facility Device Experience (MAUDE) Database provides a more complete scope of adverse events due to the mandatory reporting requirements by the FDA of implant manufactures. We reviewed the database to identify the common modes of failure and complications of total ankle implants Methods: We retrospectively reviewed reports of the MAUDE database from November 2011 to September 2018 regarding all total ankle implants. Each device in the MAUDE database is classified with a 3-letter code, we identified the 2 codes assigned to total ankle arthroplasty devices, and manually searched the FDA’s published Device Classification list for adverse events. All events were reviewed and classified. Data related to patient age or sex, surgeon, medical center location are not available in the database Results: We identified 1000 adverse reports in the period between November 2011 and September 2018. After exclusion of duplicate reports for single events or reports irrelevant to total ankle arthroplasty, a total of 697 adverse event reports were noted. The most common mode of failure was aseptic loosening (21%), followed by infection (16%), alignment and mechanical issues (instability, malalignment, malposition, stiffness, impingement) (15%), implantation issues (pin, screw or drill breakage, alignment guide problems) (9%), polyethylene related problems (wear, displaced or fractured implants) (7%), bony and soft tissue overgrowth (6%), and peri-prosthetic fractures (5%). Conclusion: Our analysis reveals that the most reported mode of failure was aseptic loosening followed by infection. However, it is notable that there are a significant number of issues with implant alignment and mechanics, complications during implantation and polyethylene component failure that are under-reported in the literature. Knowledge of these adverse events may help surgeons avoid similar complications as well as lead to improvement in component implantation and design

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Clinical Radiographical Outcomes and Complications after a Brand-New Total Ankle Replacement Design through an Anterior Approach: A Retrospective at a Short-Term Follow Up

Journal of Clinical Medicine ◽

10.3390/jcm10112258 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2258

Author(s):

Massimiliano Mosca ◽

Silvio Caravelli ◽

Emanuele Vocale ◽

Simone Massimi ◽

Davide Censoni ◽

...

Keyword(s):

Mean Value ◽

Total Ankle Replacement ◽

P Value ◽

Ankle Osteoarthritis ◽

Ankle Replacement ◽

Patient Reported ◽

End Stage ◽

Term Performance ◽

Replacement Design

Recently, the progress in techniques and in projecting new prosthetic designs has allowed increasing indications for total ankle replacement (TAR) as treatment for ankle osteoarthritis. This retrospective work comprehended 39 subjects aged between 47 and 79 years old. The patients, observed for at least 12 months (mean follow up of 18.2 ± 4.1 months), have been evaluated according to clinical and radiological parameters, both pre- and post-operatively. The AOFAS and VAS score significantly improved, respectively, from 46.2 ± 4.8 to 93.9 ± 4.1 and from 7.1 ± 1.1 to 0.7 ± 0.5 (p value < 0.05). At the final evaluation, the mean plantarflexion passed from 12.2° ± 2.3° to 18.1° ± 2.4° (p value < 0.05) and dorsiflexion from a pre-operative mean value of 8.7° ± 4.1° to 21.7° ± 5.4° post-operatively (p value < 0.05). This study found that this new total ankle replacement design is a safe and effective procedure for patients effected by end-stage ankle osteoarthritis. Improvements have been demonstrated in terms of range of motion, radiographic parameters and patient-reported outcomes. However, further studies are needed to assess the long-term performance of these prostheses.

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