The scandinavian total ankle replacement: survivorship at 5 and 8 years comparable to other series

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.

Current Trends in Total Ankle Replacement

Ankle arthritis can result in significant pain and restriction in range of motion. Total ankle replacement (TAR) is a motion-preserving surgical option used as an alternative to total ankle arthrodesis to treat end-stage ankle arthritis. There are several generations of TAR techniques based on component design, implant material, and surgical technique. With more recent TAR implants, an attempt is made to minimize bone resection and mirror the native anatomy. There are more than 20 implant devices currently available. Implant survivorship varies among prosthesis types and generations, with improved outcomes reported with use of the more recent third- and fourth-generation ankle implants. Pre- and postoperative assessments of TAR are primarily performed by using weight-bearing radiography, with weight-bearing CT emerging as an additional imaging tool. Preoperative assessments include those of the tibiotalar angle, offset, and adjacent areas of arthritis requiring additional surgical procedures. US, nuclear medicine studies, and MRI can be used to troubleshoot complications. Effective radiologic assessment requires an understanding of the component design and corresponding normal perioperative imaging features of ankle implants, as well as recognition of common and device-specific complications. General complications seen at radiography include aseptic loosening, osteolysis, hardware subsidence, periprosthetic fracture, infection, gutter impingement, heterotopic ossification, and syndesmotic nonunion. The authors review several recent generations of TAR implants commonly used in the United States, normal pre- and postoperative imaging assessment, and imaging complications of TAR. Indications for advanced imaging of TAR are also reviewed. ©RSNA, 2023 Supplemental material is available for this article. Test Your Knowledge questions for this article are available through the Online Learning Center.

Revision of total ankle arthroplasty: Survival and medium-term functional results

BACKGROUND

The objective of this study was to analyze the results and survivorship of total ankle arthroplasty (TAA) revision surgery with standard (Salto Talaris®) or revision (Salto Talaris XT®) implants.

METHODS

Between January 2005 and December 2017, all patients undergoing TAA revision at our hospital were included. Indications for revision, type of surgery performed, improvement in function assessed with the AOFAS score, occurrence of complications and implant survival at last follow-up were analyzed.

RESULTS

In the end, 25 TAA patients who had undergone revision (11 unipolar, 14 bipolar) were included. The mean follow-up time was 5.1 ± 1.9 years. At the last follow-up, function was improved compared to the preoperative AOFAS score (51.3 ± 17.5 vs. 83.5 ± 10.1; p < .001), but not plantar flexion (17.5 ± 5.7 vs. 15.4 ± 7.1; p = 0.28) or dorsal flexion (7 ± 5.6 vs. 8.3 ± 4.9; p = 0.3). Complications occurred in six patients (24 %) that led to reoperation: three infections, one lateral impingement, one implant malposition, and one hindfoot alignment disorder. At the last follow-up, implant survival was 96 %, but the probability of survival without reoperation was 78.7 ± 8.5 % at 4 years.

CONCLUSION

TAA revision by arthroplasty is feasible, produces good functional results in the medium term, but has a high risk of complications. The challenge of revision TAA is managing the loss of bone stock and anchoring the new implants.

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.

Cone-Beam Weight-Bearing Computed Tomography of Ankle Arthritis and Total Ankle Arthroplasty

Weight-bearing computed tomography has multiple advantages in evaluating the hindfoot and ankle. It can assess hindfoot and ankle alignment, pathology in ankle arthritis, and complications related to total ankle replacements. It is an essential tool in ankle osteoarthritis diagnostic, preoperative planning, and total ankle replacement outcomes. It allows for better accuracy and reproducibility of alignment and implant size. In addition, it has the potential to more assertively detect complications related to weight bearing.

Pulmonary Embolism, Mortality, and Medical Complications Following a Total Ankle Replacement: A Systematic Review and Meta-analysis

BACKGROUND

There is sparse data on the incidence of thromboembolic and medical complications following total ankle replacements. The aim of this systematic review was to determine the risk of deep vein thrombosis and pulmonary embolism as well as mortality and medical complications following ankle replacements.

METHODS

A systematic review was undertaken using all levels of evidence following PRISMA guidelines. Of the 1657 articles identified, 25 met the inclusion criteria. The inclusion criteria were a primary total ankle replacement with the recording of medical complications and/or thromboembolic events and/or mortality data. Two reviewers independently reviewed all articles. Quantitative methods were used to pool the percentages with complications across studies.

RESULTS

The pooled percentage with reported symptomatic deep vein thrombosis across 18 studies was 0.07% (95% CI 0.001%-0.59%). The pooled percentage with reported postoperative pulmonary embolism across 8 studies was 0.01% (95% CI 0.001%-0.03%). The pooled postoperative reported mortality was 0.06% (95% CI 0.001%-0.24%). Other medical complications had low incidences.

CONCLUSION

Our study indicates rates of reported thromboembolic events of less than 1 in 1000. Notably the level of evidence analyzed was mainly Level III and IV, likely underestimating the true incidence of these events because of recall and medical record limitations, and we had insufficient information on usage of chemoprophylaxis among these patients.

LEVEL OF EVIDENCE

Level IV, systematic review based on all levels of evidence including case series.

Randomized Controlled Trial Comparing Early Mobilization vs Six Weeks of Immobilization in a Walking Cast Following Total Ankle Replacement

Rehabilitation for patients after total ankle replacement traditionally involves weeks of immobilization in a plaster cast followed by progressive mobilization. In a small randomized trial, we compared teh outcomes of patients who received a 3-component cementless, unconstrained, mobile-bearing prosthesis and were initially immobilised in a plaster cast for 6 weeks to thoese who received the same prosthesis but were allowed to mobilise early. Gait, clinical, patient-reported, and radiologic outcomes were measured. The study included 20 patients, 10 in the plaster cast group and 10 in the early mobilization group, and the demographics of the groups did not differ significantly. All patients were followed-up for 24 months. There were no significant differences between the 2 groups 2 years after surgery in ankle dorsiflexion, spatiotemporal gait characteristics, American Orthopaedic Foot and Ankle Society ankle-hindfoot scores, Timed Up and Go Test times, WOMAC (pain, stiffness, function) scores, SF-36 (quality-of-life) scores, or patient satisfaction (pain relief, daily-living, recreational activities, and overall) (all p > .05). Bone mineral density decrease of the medial malleolus and increase at middle tibia, calculated with DEXA scans, was significantly better in early mobilization than plaster cast group at one and 2 years postoperatively, but this was also the case preoperatively. The lack of differences in outcomes suggests that early ankle mobilization may be a safe and reliable method to enhance recovery following ankle arthroplasty with a 3-component cementless, unconstrained, mobile-bearing prosthesis. Compared to traditional plaster casting, patients who are engaged in early mobilization after arthroplasty may enjoy similar functional, mobility, quality-of-life, pain relief, activity level, and satisfaction outcomes.

Polka dot cementless talar component in enhancing total ankle replacement fixation: A parametric study using the finite element analysis approach

The primary stability of a total ankle replacement (TAR) is essential in preventing long-term aseptic loosening failure and could be quantified based on micromotion at the bone-prosthesis interface subjected to physiological loading during the normal walking. A 3D finite element analysis was conducted to investigate the current commercial STAR™ Ankle TAR bone-prosthesis interface relative micromotion (BPIRM) with addition of the talus bone minimum principal bone stresses (MPBS). Comparison was made to the proposed polka dot designs with the hemispheric feature that was demonstrated to enhance BPIRM. Parametric studies were conducted on the hemispheric features with changes in its diameter, length and shape. The FE results indicated high BPIRM at the talar component was primarily contributed by de-bonding (in the normal direction) between the talus bone and talar component. The MPBS were found to be most significant in the superior anterior and superior medial regions of the talus bone. When the pin length was increased from 1.5 to 3 mm, the BPIRM was predicted to fall below 50 μm in favour of bone in-growth. Based on the practicality of the prosthesis implantation during the surgical procedure, the final design that incorporated both the initial polka dot and 3 mm pin length in a crisscross manner was deemed to be a favorable design with reduced BPIRM and MPBS hence lowering the risk of long-term aseptic loosening.

What Are the Indications for Implant Revision in Three-component Total Ankle Arthroplasty?

BACKGROUND

Given the increasing usage of total ankle arthroplasty (TAA), a better understanding of the reasons leading to implant revision and the factors that might influence those indications is necessary to identify at-risk patients.

QUESTION/PURPOSES

Using a single-design three-component ankle prosthesis, we asked: (1) What is the cumulative incidence of implant revision at 5 and 10 years? (2) What are the indications for implant revision in our population? (3) What factors are associated with an increased likelihood of implant revision during the time frame in question?

METHODS

Between 2003 and 2017, primary TAA using a single-design three-component ankle implant was performed by or under the supervision of the implant designer in 1006 patients (1074 ankles) aged between 17 and 88 years to treat end-stage ankle osteoarthritis. No other TAA systems were used during the study period at the investigators' institution. In 68 patients with bilateral surgery, only the first TAA was considered. Of the patients treated with the study implant, 2% (16 of 1006) were lost to follow-up 5 to 14 years after TAA and were not known to have died or undergone revision, and 5% (55 of 1006) were deceased due to reasons unrelated to the procedure, leaving 935 patients for evaluation in this retrospective study. The mean (range) follow-up for the included patients was 8.8 ± 4.2 (0.2 to 16.8) years. Implant revision was performed 0.5 to 13.2 years after TAA in 12% (121 of 1006) of our patients. Survivorship free from revision was calculated using cumulative incidence (competing risks) survivorship, with death as a competing risk. The reason for each revision was classified into one of six categories according to a modified version of a previously published protocol: aseptic loosening, cyst formation, instability, deep infection, technical error, and pain without another cause. Two foot and ankle surgeons reviewed the records of all patients who underwent implant revision and assigned each patient's reason for revision to one of the six categories. The decision for assigning each patient to one of the six categories was made based on a consensus agreement. A subgroup classification of preoperative ankle alignment (neutral, mild, and major deformity) and variables of age, sex, BMI, etiology of ankle osteoarthritis, and number of preoperative and intraoperative hindfoot or midfoot procedures were used in a multinomial logistic regression and Cox regression analysis to estimate their association with reason for revision and implant survival until revision.

RESULTS

The cumulative incidence of implant revision at the mean (range) follow-up time of 8.8 ± 4.2 years (0.2 to 16.8) was 9.8% (95% confidence interval 7.7% to 11.8%). Five and 10 years after TAA, cumulative incidence was 4.8% (95% CI 3.4 to 6.1) and 12.1% (95% CI 9.7% to 14.5%), respectively. The most common reason for revision was instability (34% [41 of 121]), followed by aseptic loosening of one or more metallic components (28% [34 of 121]), pain without another cause (12% [14 of 121]), cyst formation (10% [12 of 121]), deep infection (9% [11 of 121]), and technical error (7% [9 of 121]). Ankles with a major hindfoot deformity before TAA were more likely to undergo revision than ankles with a minor deformity (hazard ratio 1.9 [95% CI 1.2 to 3.0]; p = 0.007) or neutral alignment (HR 2.5 [95% CI 1.5 to 4.4]; p = 0.001). A preoperative hindfoot valgus deformity increased revision probability compared with a varus deformity (HR 2.1 [95% CI 1.4 to 3.4]; p = 0.001).

CONCLUSION

Instability was a more common reason for implant revision after TAA with this three-component design than previously reported. All causes inducing either a varus or valgus hindfoot deformity must be meticulously addressed during TAA to prevent revision of this implant. Future studies from surgeons/institutions not involved in this implant design are needed to confirm these findings and to further investigate why a substantial number of patients had pain of unknown cause prompting revision.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Clinical and Radiographic Outcomes of Revision Total Ankle Arthroplasty Using an Intramedullary-Referencing Implant

BACKGROUND

Treatment of failed total ankle arthroplasty (TAA) is challenging. Limited literature is available on options and outcomes of revision arthroplasty despite failure rates ranging from 10% to 23% within 10 years after primary TAA. This study reports the clinical and radiographic outcomes of revision TAA using a fixed-bearing, intramedullary-referencing implant.

METHODS

A retrospective review was performed of 18 consecutive revision TAA cases between 2008-2015 using an intramedullary-referencing, fixed-bearing, 2-component total ankle system. Demographic and radiographic data were collected preoperatively, immediately postoperatively, and at the most recent follow-up. Functional outcome data were collected immediately postoperatively and at mean follow-up 47.5 months.

RESULTS

Eighteen patients underwent revision TAA, with 77.8% (14/18) implant survival. Index revision was performed most commonly for aseptic talar subsidence (55.6%) or implant loosening (tibia, 29.4%; talus, 58.9%). Following revision, 22.2% (4/18) patients required reoperation at a mean 57.3 (39-86) months. Osteolysis of the tibia, talus, and fibula was present preoperatively in 66.7% (12/18), 38.9% (7/18), and 38.9% (7/18) of patients, respectively, with progression of osteolysis in 27.8% (5/18), 11.1% (2/18) and 11.1% (2/18) of patients, respectively. Subsidence of the tibial and talar revision components was observed in 38.9% (7/18) and 55.6% (10/18) of patients, respectively. The median American Orthopaedic Foot & Ankle Society (AOFAS) score was 74.5 (26-100) and Foot Function Index (FFI) score 10.2 (0-50.4).

CONCLUSION

Early results of intramedullary-referencing revision TAA demonstrated good patient-reported outcomes with maintenance of radiographic parameters at mean follow-up of 47.5 months. Aseptic talar subsidence or loosening were the main postoperative causes of reoperation. Revision arthroplasty utilizing an intramedullary-referencing implant was a viable option for the failed TAA.

LEVEL OF EVIDENCE

Level IV, case series.

Outcome after total ankle arthroplasty with a minimum of five years follow-up: A systematic review and meta-analysis

BACKGROUND

Total ankle arthroplasty (TAA) is increasingly gaining recognition as an alternative to ankle arthrodesis in the treatment of end-stage ankle arthritis. Despite high rates of adverse events during early inception, newer generations of uncemented prosthesis and design modifications have improved outcomes. Questions remain regarding the long-term outcomes and implant survivorship of TAA.

AIM

This analysis aims to establish an updated review of intermediate and long-term clinical outcome and complication profile of TAA.

PATIENTS AND METHODS

A multi database search was performed on 14th October 2018 according to PRISMA guidelines. All articles that involved patients undergoing uncemented TAA with 5 years minimum follow-up, reported clinical outcome or complication profile of TAA were included. Seventeen observational studies were included in the review, with 1127 and 262 ankles in the 5 and 10 years minimum follow-up groups respectively.

RESULTS

Mean difference between pre- and post-operative AOFAS score was 43.60 (95%CI: 37.51-49.69, p<0.001) at 5 years minimum follow-up. At 5 years minimum follow-up, pooled proportion (PP) of prostheses revision for any reason other than polyethylene exchange was 0.122 (95%CI: 0.084-0.173), all cause revision was 0.185 (95%CI: 0.131-0.256), unplanned reoperation was 0.288 (95%CI: 0.204-0.390) and all infection was 0.033 (95%CI: 0.021-0.051). At 10 years minimum follow-up, PP of prostheses revision for any reason other than polyethylene exchange was 0.202 (95%CI: 0.118-0.325), all cause revision was 0.305 (95%CI: 0.191-0.448), unplanned reoperation was 0.422 (95%CI: 0.260-0.603) and all infection was 0.029 (95%CI: 0.013-0.066).

CONCLUSION

Despite good intermediate and long-term functional outcome measures, TAA has relatively higher revision surgery prevalence with longer follow-up periods. Further research should be directed towards identifying patient populations that would best benefit from TAA and those at greatest risk of requiring revision surgery.

A Systematic Review of Unsystematic Total Ankle Replacement Wear Evaluations

BACKGROUND

Numerous studies have reported the use of laboratory multistation joint simulators to successfully predict wear performance and functionality of hip and knee replacements. In contrast, few studies in the peer-reviewed literature have used joint simulation to quantify the wear performance and functionality of ankle replacements. We performed a systematic review of the literature on joint simulator studies that quantified polyethylene wear in total ankle arthroplasty. In addition to the quantified wear results, the load and motion parameters were identified and compared among the studies.

METHODS

A search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify articles reporting total ankle replacement polyethylene wear using joint simulators.

RESULTS

Nine studies that used joint simulators and 1 study that used a computer simulation were found. Although all studies used physiological multidirectional motions (i.e., internal/external rotation, plantar flexion/dorsiflexion, anterior/posterior translation), there was large variability among the studies in the magnitudes of these motions. Among these studies, mean non-cross-linked polyethylene wear ranged from 3.3 ± 0.4 to 25.8 ± 3.1 mm per million cycles. In contrast, mean highly cross-linked polyethylene wear ranged from 2.1 ± 0.3 to 3.3 ± 0.4 mm per million cycles. The wide distribution in wear rates was attributable to the highly inconsistent kinematic parameters and loads applied as well as differences in implant design and materials.

CONCLUSIONS

There is a severe lack of clinically applicable data on wear performance of total ankle replacements in the peer-reviewed literature. No universal set of kinematic load parameters has been established. Furthermore, only 2 of the published studies have validated their findings using independently derived data, such as retrieval analysis. These shortcomings make it difficult to compare findings as a function of design parameters and materials, or to draw clinically relevant conclusions from these simulations. More work is required to enhance the predictive capability of in vitro simulations of total ankle replacements.

CLINICAL RELEVANCE

The results of joint wear simulator studies may not accurately represent in vivo wear of total ankle replacements. Joint simulator studies should establish that they are accurately replicating in vivo wear, thus enabling use of their predictive capabilities for new materials and designs.

Positive and negative factors for the treatment outcomes following total ankle arthroplasty? A systematic review

BACKGROUND

Patient selection, surgeon's experience and implant design play an integral role and affect the treatment outcomes of total ankle arthroplasty (TAA). The aims of this study were to investigate the positive and negative attributes that correlate with different clinical and radiographic outcomes.

METHODS

Eight-nine studies matched the inclusion criteria: (1) studies of primary TAA with uncemented prosthesis; (2) mean follow-up of no less than 2-year; (3) reports of clinical and radiographic outcomes, and exclusion criteria: (1) non-English study; (2) more than one type of prosthesis without separated data; (3) kin studies with shorter follow-up or smaller cohort. Age, etiology, preoperative deformity, surgeon's experience, follow-up duration and prosthetic type were studied with respect to different outcomes by mixed-effects logistic regression analysis.

RESULTS

Patients factor: older patients reported less pain or stiffness and demonstrated less radiographic loosening which did not require additional surgical intervention. More traumatic arthritis experienced adjacent joints degeneration after TAA. Surgeon factor: less experienced surgeons had more intraoperative complications. Lack of experience for complications management without implant retrieval during early period might result in more revisions or fusion was done. Prosthetic factor: updated instrumentation decreased malalignment. If the polyethylene (PE) insert was significantly narrower than the metal components more implant instability and subsequent severe particulate wear was seen. Designs with flat-on-flat articulation and ridge at the center of the talar component associated with more PE fracture. Minimal bone resection reduced postoperative fractures. A flat cut of the tibial component and a flat undersurface with press-fit by two screws or pegs of the talar component demonstrated less postoperative fractures, whereas a syndesmosis fusion and a small triangular shape with one central fin of the talar component experienced more loosening which did not require additional surgery. Anatomic conical shape of the talar component seemed to reduce adjacent joint degeneration. Finally, fewer failures were found in patients who received HINTEGRA and Salto Talaris.

CONCLUSIONS

Based on our investigation, some positive and negative factors for different clinical and radiographic outcomes were found, which should be taken into consideration in clinical practice and ankle implant design.

The Bologna-Oxford ankle replacement: a case series of clinical and radiological outcomes

PURPOSE

The Bologna-Oxford (BOX®) total ankle arthroplasty (TAA) is a three-component mobile-bearing implant gaining popularity in Europe. We aimed to analyse the outcomes of this TAA.

METHODS

We retrospectively analysed data on 34 consecutive BOX® TAAs performed at a single centre with a mean follow-up of 58 months. Radiographic outcomes, such as periprosthetic lucency and alignment, were measured and recorded. Prospectively captured clinical scores and range of movement (ROM) were also recorded.

RESULTS

There were significant improvements in patient-reported outcome scores recorded in the Manchester-Oxford Foot Questionnaire (MOxFQ) for pain (43.8 ± 20.2, p < 0.001), standing and walking (55.6 ± 19.8, p < 0.001), social activities (45.0 ± 26.9, p < 0.02) and visual analogue score (VAS) (3.1 ± 2.5, p < 0.001). Mean improvement in ROM postoperatively was 18.7° (p < 0.001), with post-operative dorsiflexion 8.8° (10°-25°) and plantar flexion 32.6° (20°-40°). There was evidence of asymptomatic lucency on five radiographs (15%), which was present in 10% at three years. Nine patients had complications (26%): six (18%) requiring secondary surgery and one requiring revision (3%) for infection.

CONCLUSIONS

We have demonstrated 97% survivorship at a mean of 58 months. There are maintained improvements in clinical and radiological outcomes and reoperation that are consistent with the literature.

Comparing 30-day all-cause readmission rates between tibiotalar fusion and total ankle replacement

BACKGROUND

End-stage ankle arthritis is a debilitating condition that negatively impacts patient quality of life. Tibiotalar fusion and total ankle replacement are treatment options for managing ankle arthritis. Few studies have examined short term readmission rates of these two procedures. The objective of this study was compare all-cause 30-day readmission rates between patients undergoing tibiotalar fusion vs. total ankle replacement.

METHODS

This study queried the Nationwide Readmission Database (NRD) from 2013-2014 and used international classification of disease, 9th revision (ICD-9) procedure codes to identify all patients who underwent a tibiotalar fusion or a total ankle replacement. Comorbidities, insurance status, hospital characteristics, and readmission rates were statistically compared between the two cohorts. Risk factors were then identified for 30-day readmission.

RESULTS

A total of 5660 patients were analyzed with 2667 in the tibiotalar fusion cohort and 2993 in the total ankle replacement cohort. Univariate analysis revealed that the readmission rate after tibiotalar fusion (4.4%) was statistically greater than after total ankle replacement (1.4%). Multivariable regression analysis indicated that deficiency anemia (OR 2.18), coagulopathy (OR 3.51), renal failure (OR 2.83), other insurance relative to private (OR 3.40), and tibiotalar fusion (OR 2.51) were all statistically significant independent risk factors for having a readmission within 30-days.

CONCLUSIONS

These findings suggest that during the short-term period following discharge from the hospital, patients who received a tibiotalar fusion are more likely to experience a 30-day readmission. These findings are important for decision making when a surgeon encounters a patient with end stage ankle arthritis.

LEVEL OF EVIDENCE

Level III, cohort study.

Algorithm for Management of Periprosthetic Ankle Fractures

BACKGROUND

Evidence on the management of and outcomes from periprosthetic fractures about a total ankle replacement (TAR) are limited. The purpose of this study was to develop an algorithm for the management of patients with postoperative periprosthetic fractures about a TAR.

METHODS

This was a retrospective analysis of patients undergoing a TAR from 2007 through 2017 with a subsequent periprosthetic fracture >4 weeks from index surgery. Implant stability was defined radiographically and intraoperatively where appropriate. Univariate and multivariate analyses were used to identify differences in outcomes. Thirty-two patients were identified with a remote TAR periprosthetic fracture with an average follow-up of 26 months (range, 3-104 months).

RESULTS

Most fractures were located about the medial malleolus (62.5%); the majority of fractures (75%) were deemed to have stable implants. Fractures of the talus always had unstable implants and always required revision TAR surgery (100%, P = .0002). There was no difference in patient-reported outcomes between stable and unstable fractures at an average of 36 months. In a multivariate analysis, fracture location (talus), less time to fracture, and implant type were found to be predictive of unstable implants ( P < .001). Implant stability was independently associated with the need for revision surgery ( P < .049). Nonoperative treatment was independently associated with treatment failure ( P < .001).

CONCLUSION

The majority of stable fractures about a TAR required operative fixation. Management with immobilization was fraught with a high rate of subsequent surgical intervention. We found that fractures about the talus required revision TAR surgery or arthrodesis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Long-term Follow-up Results of Buechel-Pappas Ankle Arthroplasty

BACKGROUND

Total ankle replacement (TAR) is gaining popularity as a treatment option for ankle osteoarthritis. Long-term implant survival is a critical outcome to determine the success of the TAR implant. The Buechel-Pappas (BP) implant is a second-generation mobile bearing implant. The aim of this study was to analyze the BP implant survivorship at 10-year follow-up, make a subanalysis between patient groups, and evaluate long-term functional outcomes.

METHODS

Data of 86 patients who received 101 BP implants between 1993 and 2010 were obtained from a prospectively documented database. Subanalyses were done for patients diagnosed with inflammatory joint disease and noninflammatory joint disease, and patients with preoperative tibiotalar neutral and nonneutral alignment. A Kaplan-Meier curve was used for survival analysis. Long-term functional outcomes were assessed with the following patient-reported outcome measures: Foot and Ankle Outcome Score (FAOS), Foot and Ankle Ability Measure (FAAM), Short Form-36 (SF-36) Stand Version 2.0 Health Survey and 3 anchor questions.

RESULTS

The survival rate of the BP implant at 10 years was 86% (95% confidence interval, 78%-93%). A total of 31 patients (36%) required 55 reoperations, and in 13 patients (15%) a revision procedure was performed. In this series, no significant difference in 10-year survival rate was found between neither the inflammatory joint disease and noninflammatory joint disease group ( P = .47), nor the tibiotalar neutral and nonneutral alignment group ( P = .16). At a mean follow-up of 16.8 years for 21 patients, the mean FAOS activities of daily living (ADL) and FAAM ADL subscale scores were 75/100 and 56/100 points. The mean physical component summary (PCS) and mental component summary (MCS) of the SF-36 were 34/100 and 51/100 points, respectively.

CONCLUSION

A survival rate of 86% was found at 10-year follow-up for the Buechel-Pappas implant. Our series demonstrated no significant difference in 10-year survival rates between the 2 patient subgroups. Long-term results of the various functional outcomes varied between poor and moderate.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Total ankle arthroplasty: what are the risks?: a guide to surgical consent and a review of the literature

AIMS

Total ankle arthroplasty (TAA) surgery is complex and attracts a wide variety of complications. The literature lacks consistency in reporting adverse events and complications. The aim of this article is to provide a comprehensive analysis of each of these complications from a literature review, and to compare them with rates from our Unit, to aid clinicians with the process of informed consent.

PATIENTS AND METHODS

A total of 278 consecutive total ankle arthroplasties (251 patients), performed by four surgeons over a six-year period in Wrightington Hospital (Wigan, United Kingdom) were prospectively reviewed. There were 143 men and 108 women with a mean age of 64 years (41 to 86). The data were recorded on each follow-up visit. Any complications either during initial hospital stay or subsequently reported on follow-ups were recorded, investigated, monitored, and treated as warranted. Literature search included the studies reporting the outcomes and complications of TAA implants.

RESULTS

There were wound-healing problems in nine ankles (3.2%), superficial infection in 20 ankles (7.2%), and deep infection in six ankles (2.2%). Intraoperative fractures occurred in medial malleoli in 27 ankles (9.7%) and in lateral malleoli in four ankles (1.4%). Aseptic loosening and osteolysis were seen 16 ankles (5.8%). Fracture of the polyethylene component occurred in one ankle (0.4%) and edge-loading in seven ankles (2.5%). We observed medial gutter pain in 31 ankles (11.1%). The incidence of thromboembolism occurred in two ankles (0.7%). The results were found to be comparable to the previously reported complications of total ankle arthroplasty in the literature.

CONCLUSION

Total ankle arthroplasty continues to evolve and improve the ankle function. Despite high overall complication rates with TAA surgery, most complications appear to be minor and do not affect final clinical outcome. Our results and literature review will help in the consent process and provide detailed complication rates for an informed consent. Cite this article: Bone Joint J 2018;100-B:1352-8.

Short-Term Perioperative Complications and Mortality After Total Ankle Arthroplasty in the United States

This study sought to identify patient and operative demographics associated with 30-day perioperative complications in patients undergoing total ankle arthroplasty as recorded in the National Surgical Quality Improvement Project database. Complications were divided into local and systemic and further subcategorized as major and minor. A total of 404 patients underwent total ankle arthroplasty between 2007 and 2014 as captured in the National Surgical Quality Improvement Project database. The overall complication rate was 2.4% with 0.5% mortality and 0.2% infection rate. Length of hospital stay, both as an end point at >5 days and as a continuous variable, was associated with overall complications (odds ratio [OR] = 9.90, P = .002 and OR = 1.52, P = .006, respectively). Patient characteristics that predicted perioperative morbidity included presence of 3 or comorbidities (OR = 8.48, P = 0.038), American Society of Anesthesiologists class III, and history of previous cardiac surgery (OR = 12.22, P = .033). Correct patient selection is imperative in achieving improved outcomes and those that are at risk for complications should be counseled as such.

LEVELS OF EVIDENCE

Level III: Database case control study.

The Top 50 most-cited articles on Total Ankle Arthroplasty: A bibliometric analysis

Total Ankle Arthroplasty (TAA) is a relatively new and evolving field in Foot and Ankle surgery. We conducted a citation analysis to identify the characteristics of the top 50 most cited articles on total ankle arthroplasty. Using the Web of Science database and the search strategy total ankle arthroplasty OR total ankle replacement, we identified 2445 articles. After filtering for relevant articles, the top 50 cited articles on total ankle arthroplasty were retrieved for descriptive and statistical analysis. The publication years ranged from 1979 to 2013. USA was the most productive country in terms of research output, followed by the UK. Though citation analysis has its flaws, this is a comprehensive list of the top 50 articles significantly impacting literature on total ankle arthroplasty. Based on our study, we conclude that there is marked deficiency of high level articles with respect to the number of citations and future researches need to cater to this question to produce high quality studies.

Finite element analysis of biomechanical effects of total ankle arthroplasty on the foot

Background

Total ankle arthroplasty is gaining popularity as an alternation to ankle arthrodesis for end-stage ankle arthritis. Owing to the complex anatomical characteristics of the ankle joint, total ankle arthroplasty has higher failure rates. Biomechanical exploration of the effects of total ankle arthroplasty on the foot and ankle is imperative for the precaution of postoperative complications. The objectives of this study are (1) to investigate the biomechanical differences of the foot and ankle between the foot with total ankle arthroplasty and the intact foot and (2) to investigate the performance of the three-component ankle prosthesis.

Methods

To understand the loading environment of the inner foot, comprehensive finite element models of an intact foot and a foot with total ankle arthroplasty were developed to simulate the stance phase of gait. Motion analysis on the model subject was conducted to obtain the boundary and loading conditions. The model was validated through comparison of plantar pressure and joint contact pressure between computational prediction and experimental measurement. A pressure mapping system was used to measure the plantar pressure during balanced standing and walking in the motion analysis experiment, and joint contact pressure at the talonavicular joint was measured in a cadaver foot.

Results

Plantar pressure, stress distribution in bones and implants and joint contact loading in the two models were compared, and motion of the prosthesis was analysed. Compared with the intact foot model, averaged contact pressure at the medial cuneonavicular joint increased by 67.4% at the second-peak instant. The maximum stress in the metatarsal bones increased by 19.8% and 31.3% at the mid-stance and second-peak instants, respectively. Force that was transmitted in three medial columns was 0.33, 0.53 and 1.15 times of body weight, respectively, at the first-peak, mid-stance and second-peak instants. The range of motion of the prosthetic ankle was constrained in the frontal plane. The lateral side of the prosthesis sustained higher loading than the medial side.

Conclusion

Total ankle arthroplasty resulted in great increase of contact pressure at the medial cuneonavicular joint, making it sustain the highest contact pressure among all joints in the foot. The motion of the prosthesis was constrained in the frontal plane, and asymmetric loading was distributed in the bearing component of the ankle prosthesis in the mediolateral direction.

The translational potential of this article

Biomechanical variations resulted from total ankle arthroplasty may contribute to negative postoperative outcomes. The exploration of the biomechanical performance in this study might benefit the surgeons in the determination of surgical protocols to avoid complications. The analysis of the performance of the ankle prosthesis could enhance the knowledge of prosthetic design.

Midterm Outcomes of a Fixed-Bearing Total Ankle Arthroplasty With Deformity Analysis

BACKGROUND

We present our results with an INBONE I (Wright Medical, Memphis, TN) prosthesis that have a minimum of 4 to 10 years of follow-up and include a preoperative deformity analysis on outcomes.

METHODS

A consecutive series of 149 patients, from 2007 to 2011, at a single institution were enrolled. Pain and patient-reported function were assessed preoperatively and at yearly follow-ups. We analyzed the data for complications, reoperations, and failures (defined as undergoing revision for exchange or removal of one or both metallic components for any reason). Patients were also grouped according to coronal plane tibiotalar alignment; either ≥10 degrees or <10 degrees, and these outcomes were compared. Our follow-up ranged from 48 to 113 months (average 5.9 years).

RESULTS

There was significant improvement ( P < .05) in the visual analog scale for pain, American Orthopaedic Foot & Ankle Society hindfoot scale, Short Musculoskeletal Function Assessment, and Short Form 36-Item Health Survey scores at most recent follow-up. There were 14 implant failures with overall survivorship of 90.6% (135/149). Reasons for failure included cysts/loosening (7), talar subsidence (4), fractured component (1), impingement pain (1), and infection (1). Seventy-two patients (48.3%) with preoperative coronal plane deformity of ≥10 degrees varus or valgus were compared to 78 patients (51.7%) with <10 degrees deformity. There was no difference in patient outcome scores or revision rates between these patient groups. There was a statistically significant difference ( P = .039) in reoperation rates among patients with ≥10 degrees deformity (22.2%) compared to those without such a deformity (37.7%) Conclusion: Patients who underwent INBONE I fixed-bearing total ankle arthroplasty demonstrated significant improvement in outcomes at a mean of 5.9 years. Catastrophic talar component collapse did occur (2.7% of cases), but relatively rarely. The patients with preoperative coronal plane tibiotalar deformity had similar pain relief, function, and need for revision of implant components. Despite the presumed shortcomings of the INBONE I's design, this implant showed promising results, with or without deformity, at midterm follow-up with survivorship of 90.6%.

LEVEL OF EVIDENCE

Level III, comparative study.

Complex Total Ankle Arthroplasty

Total ankle arthroplasty is a viable surgical technique for the treatment of end-stage degenerative joint disease. With continued advancement in prosthetic design, refined surgical techniques, and improved outcomes, the indications for total ankle replacement have expanded to include cases of increasing complexity. With meticulous preoperative planning and exacting execution, many frontal plane deformities and cases of avascular necrosis can now be successfully addressed at the time of prosthesis implantation or in a staged procedure.

Survival of the Scandinavian total ankle replacement (STAR): results of ten to nineteen years follow-up

PURPOSE

The purpose of this study was to evaluate survival and clinical outcome of the Scandinavian total ankle replacement (STAR) prosthesis after a minimum of ten years up to a maximum of 19 years.

METHODS

Fifty STAR prostheses in 46 patients with end stage ankle osteoarthritis operated between 1996 and 2006 by the same surgeon (MH) were included. Minimal follow-up was ten years (median 14.6 years, 95% confidence interval [CI] 12.9-16.4). Clinical (Kofoed score) and radiological assessments were taken before the operation and at one, ten (+2), and 16 (±3) years after implantation. The primary endpoint was defined as exchange of the whole prosthesis or conversion to arthrodesis (def. 1), exchange of at least one metallic component (def. 2), or exchange of any component including the inlay (due to breakage or wear) (def. 3). Survival was estimated according to Kaplan-Meier. Further reoperations related to STAR were also recorded.

RESULTS

The ten year survival rate was (def. 1) 94% (CI 82-98%), (def. 2) 90% (CI, 77-96%), and (def. 3) 78% (CI 64-87%). The 19-year survival rate was (def. 1) 91% (CI 78-97%), (def. 2) 75% (CI 53-88%), and (def. 3) 55% (CI 34-71%). Considering any re-operations related to STAR, 52% (26/50) of prostheses were affected by re-operations. Mean pre-operative Kofoed score was 49, which improved to 84 after one year (n = 50), to 90 after ten years (n = 46), and to 89 after 16 years (n = 28).

CONCLUSIONS

The survival rate for def. 1 and 2 was high. However, re-operations occurred in 52% of all STAR prosthesis.

STUDY DESIGN

Retrospective cohort study, evidence Level 4.

Dealing with the Stiff Ankle: Preoperative and Late Occurrence

In patients with a stiff ankle replacement, appropriate resection of scarred capsular structures, hypertrophic bone debridement, and careful release of tendons should be performed to achieve good outcomes. Appropriately sized and correctly implanted components are required to restore ankle function to as normal as possible. Although not proven, the better a total ankle replacement is balanced, the less likely scar and heterotopic bone formation will occur. In patients with a stiff and painful ankle replacement, a preoperative diagnostic workup is mandatory to understand the underlying pathologic process and plan appropriate treatment. All underlying causes should be addressed.

Long-term Functional and Radiographic Outcome of a Mobile Bearing Ankle Prosthesis

BACKGROUND

Total ankle arthroplasty is an accepted alternative to arthrodesis of the ankle. However, complication and failure rates remain high. Long-term results of the Scandinavian Total Ankle Replacement (STAR) are limited, with variable complication and failure rates observed. This prospective study presents the long-term survivorship and postoperative complications of the STAR prosthesis.

METHODS

Between May 1999 and June 2008, 134 primary total ankle arthroplasties were performed using the STAR prosthesis in 124 patients. The survivorship, postoperative complications, and reoperations were recorded, with a minimum follow-up period of 7.5 years. Clinical results were assessed using the Foot Function Index and the Kofoed score. The presence of component migration, cysts, and radiolucency surrounding the prosthesis components, heterotopic ossification, and progression of osteoarthritis in adjacent joints were determined.

RESULTS

The cumulative survival was 78% after the 10-year follow-up period. An ankle arthrodesis was performed in 20 ankles (14.9%) that failed. Fourteen polyethylene insert fractures occurred (10.4%). Other complications occurred in 29 ankles (21.6%), requiring secondary procedures in 21 ankles (15.7%). Nevertheless, the postoperative clinical results improved significantly. Osteolytic cysts were observed in 61 ankles (59.8%) and the surface area of these cysts increased during follow-up, without any association with the prosthesis alignment or clinical outcome. Heterotopic ossification at the medial malleolus was present in 58 cases (56.8%) and at the posterior tibia in 73 cases (71.6%), with no effect on clinical outcome. Osteoarthritis of the subtalar and talonavicular joint developed in 9 (8.8%) and 11 cases (10.8%), respectively.

CONCLUSION

The long-term clinical outcomes for the STAR were found to be satisfactory. Although these results are consistent with previous studies, the survival and complication rates are disappointing compared to knee and hip arthroplasty. Higher rates of successful outcomes following ankle arthroplasty are important, and these results highlight the need for further research to clarify the origin and significance of the reported complications.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Pulmonary embolism and mortality following total ankle replacement: a data linkage study using the NJR data set

OBJECTIVE

To determine the mortality rate following total ankle replacement (TAR) and incidence of 90 day pulmonary embolism (PE) along with the associated risk factors.

DESIGN

Data-linkage study of the UK National Joint Registry (NJR) data and Hospital Episodes Statistics (HES) database. Linkage was performed in a deterministic fashion. HES episodes 90 days after the index procedure were analysed for PE. Mortality data were obtained pertaining to all the index procedures from the NJR for analysis.

PARTICIPANTS

All primary and revision ankle replacement patients captured on the NJR between February 2008 and February 2013.

RESULTS

The 90-day mortality following TAR was 0.13% (95% CI 0.03 to 0.52) and 1-year mortality was 0.72% (95% CI 0.40 to 1.30); no deaths were as a result of PE. The incidence of PE within 90 days following primary TAR was 0.51% (95% CI 0.23 to 1.13). There was only one PE following revision surgery. Patients with an Royal College of Surgeons Charlson score greater than zero were at 13 times greater risk of PE (p=0.003).

CONCLUSIONS

There is low incidence of PE following TAR, but multiple comorbidities are a leading risk factor for its occurrence.

Surgical treatments for osteoarthritis

There are two main surgical treatments for osteoarthritis: conservative treatments, where the damaged cartilage is left in place, and radical treatments, where the cartilage is replaced by an artificial endoprosthesis; this latter procedure is termed joint arthroplasty. These treatments are only offered to symptomatic patients. Arthrodesis is yet another surgical intervention in cases of osteoarthritis. It will sacrifice the joint's articular function and is performed on small osteoarthritic joints, such as wrists and ankles, for instance. Osteoarthritis symptoms are usually the consequence of an imbalance between the load applied to a joint and the surface available to support that load. Therefore, conservative treatments will either tend to decrease the load exerted on the joint, such as in a tibial valgus osteotomy for instance, or to improve the articular surface supporting that load. Sometimes, both can be provided at the same time; the peri-acetabular osteotomy for hip dysplasia is an example of such a procedure. Conservative treatments are usually offered to young patients in order to delay, if not avoid, the need for a joint prosthesis. They are usually performed before osteoarthritis appears or at an early stage. Joint arthroplasties have overwhelmingly excellent functional results and today's research is directed towards providing rapid recovery, very long-term stability, and the assurance of a good functionality in extreme conditions. However, complications with joint arthroplasties can be serious with little, if any, reasonable salvage solution. Therefore, these procedures are offered to patients who have failed adequate medical treatment measures.

Total ankle replacement

BACKGROUND

About 1% of adults suffer from painful osteoarthritis of the ankle. The current literature contains no information on the percentage of such patients who derive long-term relief of symptoms from conservative treatment. Advanced ankle osteoarthritis can be treated with non-joint-preserving measures, such as total ankle replacement and ankle fusion.

METHODS

This review is based on selected relevant publications, guidelines from Germany and abroad, and the authors' personal experience.

RESULTS

Before surgery is considered, conservative measures such as physiotherapy and orthopedic aids should be used to the fullest possible extent. No randomized trials have yet been published comparing total ankle replacement with ankle fusion. Total ankle replacement with newer types of prosthesis yields good to very good intermediate-term and long-term results, with mean success rates of up to 90% at 10 years (range, 68-100%). Independent risk factors for the failure of ankle replacement are age over 70 years (odds ratio [OR] 3.84), primary osteoarthritis (OR 7.19), post-traumatic osteoarthritis (OR 6.2), and type of prosthesis (e.g., single hydroxyapatite coating: OR 15.04). The average range of motion of the replaced ankle joint is 25° to 30°, with values as high as 60°.

CONCLUSION

Total ankle replacement is a good treatment option for complete, end-stage ankle arthritis. It can restore joint function and make the patient mobile with little or no pain. There are, however, many contraindications to be taken into account. There is a need for further studies of the biomechanics of arthritic and replaced ankle joints and for long-term follow-up studies of total ankle replacement.

Functional and radiological outcome of periprosthetic fractures of the ankle

The incidence of periprosthetic fractures of the ankle is increasing. However, little is known about the outcome of treatment and their management remains controversial. The aim of this study was to assess the impact of periprosthetic fractures on the functional and radiological outcome of patients with a total ankle arthroplasty (TAA).

A total of 505 TAAs (488 patients) who underwent TAA were retrospectively evaluated for periprosthetic ankle fracture: these were then classified according to a recent classification which is orientated towards treatment. The outcome was evaluated clinically using the American Orthopedic Foot and Ankle Society (AOFAS) score and a visual analogue scale for pain, and radiologically.

A total of 21 patients with a periprosthetic fracture of the ankle were identified. There were 13 women and eight men. The mean age of the patients was 63 years (48 to 74). Thus, the incidence of fracture was 4.17%.

There were 11 intra-operative and ten post-operative fractures, of which eight were stress fractures and two were traumatic. The prosthesis was stable in all patients. Five stress fractures were treated conservatively and the remaining three were treated operatively.

A total of 17 patients (81%) were examined clinically and radiologically at a mean follow-up of 53.5 months (12 to 112). The mean AOFAS score at follow-up was 79.5 (21 to 100). The mean AOFAS score in those with an intra-operative fracture was 87.6 (80 to 100) and for those with a stress fracture, which were mainly because of varus malpositioning, was 67.3 (21 to 93). Periprosthetic fractures of the ankle do not necessarily adversely affect the clinical outcome, provided that a treatment algorithm is implemented with the help of a new classification system.

Cite this article: Bone Joint J 2015;97-B:950–6.

Intermediate to Long-Term Outcomes of Total Ankle Replacement with the Scandinavian Total Ankle Replacement (STAR)

BACKGROUND

The Scandinavian Total Ankle Replacement (STAR) prosthesis has been in clinical use since 1981, with investigational use in the U.S. since 1998. Few studies of the North American version of the STAR are available. This prospective cohort study analyzed intermediate to long-term outcomes of total ankle arthroplasty with use of the STAR prosthesis at two Canadian centers.

METHODS

Consecutive patients who received the STAR prosthesis between 2001 and 2005 were enrolled at two large, urban teaching hospitals. Patients were annually evaluated clinically, and the Ankle Osteoarthritis Scale (AOS) and the Short Form (SF)-36 were administered.

RESULTS

One hundred and eleven ankles underwent arthroplasty with the STAR prosthesis. One-half of the patients were male; the mean age was 61.9 ± 11.7 years. Sixty-eight of the ankles underwent a total of 121 additional procedures during ankle arthroplasty, including gastrocnemius release, subtalar arthrodesis, triple arthrodesis, tendoachilles lengthening, and removal of hardware. The mean duration of follow-up for all living patients without revision (seventy-three ankles) was 9.0 ± 1.0 years. Thirteen (12%) of the ankles required metal component revision at a mean of 4.3 ± 3.0 years (range, 0.6 to 10.2 years). Twenty (18%) of the prostheses underwent polyethylene bearing exchange, mostly due to fracture, at a mean of 5.2 ± 2.1 years (range, 1.5 to 9.3 years). Most (97%) of the revisions and exchanges occurred in patients with a diagnosis of primary, secondary, or posttraumatic osteoarthritis (p = 0.0003). The mean change from baseline to final follow-up was -36.5 ± 23.3 points for AOS pain, -38.6 ± 26.8 points for AOS disability, and 9.6 ± 10.3 points for the SF-36 physical component summary score. The SF-36 mental component summary score was unchanged.

CONCLUSIONS

Intermediate patient-reported outcomes were good after ankle arthroplasty with the STAR prosthesis performed by experienced surgeons, and long-term outcomes demonstrated a 12% rate of metal component revision and 18% rate of polyethylene bearing failure. The revision rate was substantially higher among the first twenty ankles than among subsequent ankles, but the early ankles had nearly two years' longer follow-up than subsequent ankles. Additional study to elucidate possible reasons for polyethylene bearing failure is warranted.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Low incidence of symptomatic thromboembolic events after total ankle arthroplasty without routine use of chemoprophylaxis

BACKGROUND

There is little evidence regarding the incidence of symptomatic venous thromboembolism (VTE) following total ankle arthroplasty (TAA) to allow formulation of treatment recommendations. The purpose of this study was to determine the incidence of symptomatic VTE events after TAA without use of chemoprophylaxis and to identify risk factors contributing to the occurrence of VTEs.

METHODS

We conducted a retrospective chart review of 637 patients (664 ankles) who received a TAA between May 2007 and January 2014 and had a minimum follow-up of 3 months. Chemoprophylaxis was prescribed only in the setting of a history of VTE or active coagulopathy. Patients were continued on chemoprophylactic agents if they were taking these medications preoperatively. A VTE event was defined when clinical signs and symptoms of deep venous thrombosis (DVT) were confirmed with use of Doppler ultrasonography or pulmonary embolism was confirmed with the use of a computed tomography scan. Routine screening for VTE was not performed.

RESULTS

The overall incidence of clinically detected VTE events was 0.60% (4/664), with 0.45% (3 patients) developing a DVT and 0.15% (1 patient) developing a nonfatal pulmonary embolism. Moreover, we identified a subset of 434 patients without identifiable preoperative risk factors who were not taking chemoprophylaxis preoperatively and were not prescribed chemoprophylaxis postoperatively. Two of these patients developed a DVT postoperatively (0.46%). Given the low incidence of clinically detected VTE, no significant correlation could be identified between the occurrence of VTE events and risk factors.

CONCLUSIONS

Our results suggest that clinically detectable VTE after TAA is uncommon. Patients without identifiable risk factors do not appear to require chemoprophylaxis following TAA. We recommend continuation of antiplatelet or anticoagulation therapy in patients who are taking these medications preoperatively and the initiation of chemoprophylaxis postoperatively in patients with known risk factors for VTE.

LEVEL OF EVIDENCE

Level IV, case series.

Current Concepts in the Management of Ankle Osteoarthritis: A Systematic Review

Ankle osteoarthritis is less common than hip or knee osteoarthritis; however, it is a relatively common presentation and is predominantly related to previous trauma. Treatments have traditionally consisted of temporizing measures such as analgesia, physiotherapy, and injections until operative treatment in the form of arthrodesis is required. More recently, interest has been increasing in both nonoperative and alternative operative options, including joint-sparing surgery, minimal access arthrodesis, and new arthroplasty designs. The present systematic instructional review has summarized the current evidence for the treatment options available for ankle osteoarthritis.

Revision Total Ankle Replacement

Introduction

The technique for revision total ankle replacement described in this article addresses the subsidence and loosening that occur when an Agility total ankle replacement fails.

Step 1: Indications and Contraindications

The main indications for revision total ankle arthroplasty include loosening and subsidence of the talar component, with no limit to the extent of subsidence or loss of talar bone stock as neither precludes use of a revision system, particularly when a flat cut on the talus can be made.

Step 2: Anterior Incision and Joint Exposure

Make the incision employing the prior anterior midline incision, create full-thickness flaps of tissue to diminish the risk of wound dehiscence, and completely expose and debride the joint as this is critical to revising the total ankle replacement correctly.

Step 3: Remove the Talar Component and Polyethylene

Remove the talar component, which is rarely difficult as it is usually loose.

Step 4: Remove the Tibial Component

When removing the tibial component, it is critical to preserve as much of the anterior tibial cortex as possible to provide support for the revision tibial component.

Step 5: Make the Tibial Bone Cut

Tibial cuts can be made proximal or distal to tibial osseous defects.

Step 6: Make the Talar Bone Cut

It is preferable to use a cutting block for the talus that attaches to the tibial guide.

Step 7: Managing Loosening and Cavitary Defects

If there is substantial bone loss around the tibia after component removal, consider impaction bone-grafting, as better bone quality makes it is easier to obtain a press fit and allow immediate weight-bearing.

Step 8: Place Trial Components

Size the tibia and talus and subsequently insert the tibial and talar trials and polyethylene simultaneously.

Step 9: Cementing Technique

In revision settings, manual cement insertion is important because there is no medullary canal to work around.

Results

We previously reported the outcomes of revision of failed Agility total ankle replacements (DePuy, Warsaw, Indiana) in forty-one patients.

Pitfalls & Challenges

Evaluation and management of the painful total ankle arthroplasty

Total ankle arthroplasty (TAA) is an increasingly popular treatment option for patients with end-stage ankle arthritis. Although improved short- and long-term clinical and radiographic outcomes have been achieved with TAA, revision surgery may be necessary in the setting of aseptic loosening, subsidence, impingement, arthrofibrosis, or infection. Factors such as patient selection, implant design, and surgical technique can all contribute to TAA failure. Treatment of patients with a painful TAA is complex and requires careful consideration of symptom history, workup, and nonsurgical and surgical treatment options. Surgical management of failed TAA includes arthrodesis, revision surgery, or below-knee amputation.

Cartilage lesions and ankle osteoarthrosis: review of the literature and treatment algorithm

The main etiology of ankle osteoarthrosis is post-traumatic and its prevalence is highest among young individuals. Thus, this disease has a great socioeconomic impact and gives rise to significant losses of patients' quality of life. The objective of its treatment is to eliminate pain and keep patients active. Therefore, the treatment should be staged according to the degree of degenerative evolution, etiology, joint location, systemic condition, bone quality, lower-limb alignment, ligament stability and age. The treatment algorithm is divided into non-surgical therapeutic methods and options for surgical treatment. Joint preservation, joint replacement and arthrodesis surgical procedures have precise indications. This article presents a review on this topic and a proposal for a treatment algorithm for this disease.

Bioactive coatings for orthopaedic implants-recent trends in development of implant coatings

Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracellular matrix proteins, biological peptides or growth factors impart bioactivity and biocompatibility to the metallic surface of conventional orthopaedic prosthesis that promote bone ingrowth and differentiation of stem cells into osteoblasts leading to enhanced osteointegration of the implant. Furthermore, coatings such as silver, nitric oxide, antibiotics, antiseptics and antimicrobial peptides with anti-microbial properties have also been developed, which show promise in reducing bacterial adhesion and prosthetic infections. This review summarizes some of the recent developments in coatings for orthopaedic implants.

Comparison of the short-term results of the first and last 50 Scandinavian total ankle replacements: assessment of the learning curve in a consecutive series

BACKGROUND

Total ankle replacement (TAR) is presently considered to be an acceptable alternative to ankle fusion for patients with debilitating conditions of the ankle. The placing of a total ankle prosthesis is a technically demanding procedure. We hypothesized that the challenging conditions could cause a longer learning curve (>30 cases), and therefore the short-term results of the first and the last 50 cases in a consecutive series of 134 cases were compared.

METHODS

The first and last consecutive 50 cases by a single surgeon in a series of 134 Scandinavian Total Ankle Replacements (STAR; Waldemar Link, Hamburg, Germany), inserted between May 1999 and May 2008, were evaluated. Operation characteristics, clinical outcome (Foot Function Index [FFI], Kofoed score), complications, and the component alignment on X-rays were assessed. The outcome measures for both groups were compared using independent Student t tests, chi-square tests, and nonparametric alternatives (P < .05).

RESULTS

Surgery time decreased from a median of 125 (83-160) to 100 (65-170) minutes (P < .001), and fewer perioperative complications were observed (12 vs 4, P = .04). The sagittal alignment of the tibial component was closer to normal in the last series (P < .001). The clinical outcome did not differ between the 2 series (median FFI: 32 [0-74] vs 25 [0-75], Kofoed score: median 71 [21-96] vs 80.5 [23-100]). The major underlying pathology did change from rheumatoid arthritis (60%) to osteoarthritis (44%; P = .002). No differences in type and number of complications were reported.

CONCLUSION

The surgery time did decrease, there were fewer perioperative fractures, and the tibial component orientation improved, suggesting the presence of a learning curve. Operative experience and a shift in major underlying pathology did not influence clinical outcome. In view of this learning curve we suggest more restrictive patient selection for at least the first 50 TARs.

LEVEL OF EVIDENCE

Level III, comparative series.

Management of failures of total ankle replacement with the agility total ankle arthroplasty

BACKGROUND

Few studies have focused on treatment following failed total ankle replacement. The purpose of this study was to report the outcomes of patients undergoing revision total ankle replacement and to propose a talar component subsidence grading system that may be helpful in making decisions regarding how to revise failed total ankle replacements in the future.

METHODS

A retrospective review was performed of fifty-three patients who underwent revision total ankle replacement and had been followed for a minimum of two years. Patients were assessed radiographically and with outcome scores. The rates of conversion to amputation or fusion were also assessed.

RESULTS

The mean follow-up period was 49.1 months after the revision arthroplasty. The average time from primary total ankle replacement to revision was fifty-one months. Forty-one of the fifty-three patients (77%) were available for follow-up. The revision arthroplasty had been converted to an arthrodesis in five of the forty-one patients, and two additional patients had undergone amputation. The most common indication for revision total ankle replacement was talar subsidence (63%; twenty-six of forty-one). Twenty-two patients (54%) had a subtalar arthrodesis performed at the time of the revision arthroplasty, with nineteen of those having a custom-designed long-stem talar component placed simultaneously. The mean radiographic measurements of component position did not change significantly postoperatively. The mean postoperative scores for the thirty-four patients with a retained total ankle replacement were: 4.4 of 10 possible points on a visual analog pain scale (VAS), 65 of 100 possible points on the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scale, 93.5 of 100 possible points on the Short-Form 12 (SF-12), 137.9 of 204 possible points on the Revised Foot Function Index (FFI-R), and 64 of 180 possible points on the Ankle Osteoarthritis Scale (AOS). The mean arc of motion radiographically was 18° preoperatively and 23° postoperatively, with all improvement occurring in plantar flexion. A lesser amount of preoperative talar subsidence was a significant predictor of a good outcome based on the AOFAS hindfoot score (p < 0.03) and the AOS (p < 0.01) score.

CONCLUSIONS

Revision arthroplasty may be considered as an alternative to arthrodesis when treating patients with a failed Agility total ankle implant.

Functional results and complication analysis after total ankle replacement: early to medium-term results from a Portuguese and Spanish prospective multicentric study

BACKGROUND

Ankle arthroplasty is increasingly being used to treat end-stage ankle osteoarthritis.

METHODS

Between January 2005 and January 2011, 159 patients have been included in an ongoing prospective multicentric study analysing the results of total ankle arthroplasty in Portugal and Spain. 119 patients (119 replacements) were available for review and were evaluated for range of motion (ROM), clinical status (American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score), complications and survivorship rate.

RESULTS

Mean follow-up was 39 months. A total of 17 complications were reported, with 7 leading to subsequent surgery (94.1% survivorship rate). Of these, there were two infections (98.3% survivorship rate), two painful subtalar arthritis, one instability, one malalignment and one tibial bone cyst. Complications not requiring further surgery were 6 intra-operative malleolar fractures and 4 cases of skin necrosis.

CONCLUSIONS

Adequate patient selection and a thorough knowledge of the surgical technique are mandatory to reduce the number of complications and increase ankle arthroplasty survivorship.

The outcome of total ankle replacement

We performed a systematic review and meta-analysis of modern total ankle replacements (TARs) to determine the survivorship, outcome, complications, radiological findings and range of movement, in patients with end-stage osteoarthritis (OA) of the ankle who undergo this procedure. We used the methodology of the Cochrane Collaboration, which uses risk of bias profiling to assess the quality of papers in favour of a domain-based approach. Continuous outcome scores were pooled across studies using the generic inverse variance method and the random-effects model was used to incorporate clinical and methodological heterogeneity. We included 58 papers (7942 TARs) with an interobserver reliability (Kappa) for selection, performance, attrition, detection and reporting bias of between 0.83 and 0.98. The overall survivorship was 89% at ten years with an annual failure rate of 1.2% (95% confidence interval (CI) 0.7 to 1.6). The mean American Orthopaedic Foot and Ankle Society score changed from 40 (95% CI 36 to 43) pre-operatively to 80 (95% CI 76 to 84) at a mean follow-up of 8.2 years (7 to 10) (p < 0.01). Radiolucencies were identified in up to 23% of TARs after a mean of 4.4 years (2.3 to 9.6). The mean total range of movement improved from 23° (95% CI 19 to 26) to 34° (95% CI 26 to 41) (p = 0.01).

Our study demonstrates that TAR has a positive impact on patients’ lives, with benefits lasting ten years, as judged by improvement in pain and function, as well as improved gait and increased range of movement. However, the quality of evidence is weak and fraught with biases and high quality randomised controlled trials are required to compare TAR with other forms of treatment such as fusion.

Cite this article: Bone Joint J 2013;95-B:1500–7.

Histologic study of periprosthetic osteolytic lesions after AES total ankle replacement. A 22 case series

INTRODUCTION

Medium-term results for total ankle replacement (TAR) are in general satisfactory, but there is a high redo rate for periprosthetic osteolysis associated with the AES implant.

HYPOTHESIS

Comparing radioclinical findings and histologic analysis of implant revision procedure specimens can account for the elevated rate of osteolysis associated with the AES TAR implant.

MATERIAL AND METHOD

In a prospective series of 84 AES TAR implants (2003-2008), 25 underwent revision for osteolysis (including three undergoing revision twice) at a mean 59.8 months. Eight patients had hydroxyapatite (HA) coated models and the others had titanium-hydroxyapatite (Ti-HA) coatings. Radiographs were systematically analyzed on Besse's protocol and evolution was monitored on AOFAS scores. The 94 specimens taken for histologic analysis during revision were re-examined, focusing specifically on foreign bodies.

RESULTS

Macroscopically, no metallosis or polyethylene wear was found at revision. AOFAS global and pain scores fell respectively from 89.7/100 at 1 year postoperatively to 72.9 before revision and from 32.5/40 to 20.6/40, although global scores were unchanged in 25% of patients. Radiologically, all patients showed tibial and talar osteolytic lesions, 45% showed cortical lysis and in 25% the implant had collapsed into the cysts. All specimens showed macrophagic granulomatous inflammatory reactions in contact with a foreign body; the cysts showed necrotic remodeling. Some of the foreign bodies could be identified on optical histologic examination with polyethylene in 95% of the specimens and metal in 60% (100% of HA-coated models and 33.3% of Ti-HA-coated models). Unidentifiable material was associated: a brownish pigment in Ti-HA-coated models (33.3%) and flakey bodies in 44.4% of the HA-coated models and 18.2% of the Ti-HA-coated models.

DISCUSSION

The phenomenon of periprosthetic osteolysis is still poorly understood, although implant wear debris seems to be implicated. All the patients with HA-coated implants with modular tibial stem had metal particles in the tissue around the implant, although their exact nature could not be determined. The double-layer Ti-HA coating may induce delamination by fretting while the biological bone anchorage is forming.

LEVEL OF EVIDENCE

Prospective cohort study - Level IV.

Thrombembolic complications after total ankle replacement

The literature addressing functional outcome and survivorship of prosthesis components is constantly growing. However, the data on thromboprophylaxis and thrombembolic complications in patients who underwent TAR are scarce. A total of 31 studies were included in the systemic literature review. The incidence of thrombembolic complications varied between 0.0 % and 9.8 %. Most commonly, low molecular weight heparin was used as thromboprophylaxis for 6 weeks postoperatively. The incidence of thrombembolic complications was comparable with that of symptomatic deep vein thrombosis in patients with total knee or hip replacement.

Complication rates after total ankle arthroplasty in one hundred consecutive prostheses

INTRODUCTION

Total ankle arthroplasty is increasingly used as an alternative to arthrodesis to treat advanced ankle arthritis. However, the outcomes and postoperative complications are poorly described.

PATIENTS AND METHODS

Between March 2005 and May 2010 114 S.T.A.R. prostheses were implanted by one surgeon at our institution. We retrospectively analysed the demographics, clinical outcomes and radiographic characteristics of 100 ankle prostheses (97 patients).

RESULTS

The average follow up was 36 months. The average preoperative AOFAS score of 36.87 (22-58) significantly increased to 75.99 postoperative. A total of 87 % of the patients reported a better life quality. Twenty-seven ankles incurred complications after primary surgery, and 21 prostheses required revision surgery, including four patients who required arthrodesis.

CONCLUSION

Our study shows a high satisfaction rate after total ankle replacement and clear pain relief. Patients with a body mass Index higher than 30 showed a higher rate of complications. Compared with ankle fusion, the rates of complications are comparable.

Early prospective clinical results of a modern fixed-bearing total ankle arthroplasty

BACKGROUND

Several fixed-bearing total ankle arthroplasty systems are available in the United States. We report on the early clinical results of the largest known cohort of patients in the United States who received a Salto Talaris total ankle replacement for the treatment of end-stage arthritis of the ankle.

METHODS

We prospectively followed sixty-seven patients with a minimum clinical follow-up of two years. Patients completed standardized assessments and underwent physical examination, functional assessment, and radiographic evaluation preoperatively and at six weeks, three months, and six months postoperatively and yearly thereafter through their most recent follow-up.

RESULTS

Implant survival at a mean follow-up time of 2.8 years was 96% when metallic component revision, removal, or impending failure was used as the end point. Three patients developed aseptic loosening, and all instances involved the tibial component. One of the three patients underwent revision to another fixed-bearing total ankle arthroplasty system, one patient is awaiting revision surgery, and the third patient has remained minimally symptomatic and fully functional without additional surgery. Forty-five patients underwent at least one additional procedure at the time of the index surgery. The most common concurrent procedure performed was a deltoid ligament release (n = 21). Eight patients underwent additional surgery following the index arthroplasty, most commonly debridement for medial and/or lateral impingement (n = 4). As of the most recent follow-up, patients demonstrated significant improvement in pain scores, American Orthopaedic Foot & Ankle Society hindfoot score, and functional scores.

CONCLUSIONS

Early clinical results indicate that the Salto Talaris fixed-bearing total ankle arthroplasty system can provide significant improvement in pain, quality of life, and standard functional measures in patients with end-stage ankle arthritis.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Periprosthetic fractures in total ankle replacement: classification system and treatment algorithm

BACKGROUND

Despite progress in implant design and surgical technique, the reported number of periprosthetic ankle fractures following total ankle joint replacement continues to increase. A treatment-oriented classification of these fractures has not yet been reported. The purpose of this study was to evaluate the prevalence, cause, and location of periprosthetic fractures and the stability of the associated prosthetic components after total ankle replacement and to develop a method of classification.

METHODS

Data regarding 503 total ankle replacements with a mean follow-up of 14.7 months were reviewed. The prevalence, location, and possible cause of the fractures as well as prosthesis stability were analyzed and a systematic method of classification based on these factors was developed.

RESULTS

Twenty-one patients (4.2%) with a periprosthetic fracture were identified. The fracture was intraoperative (Type 1) in eleven patients (2.2%) and postoperative in the remaining ten (2.0%). Two of the latter fractures were traumatic (Type 2) and eight were stress fractures (Type 3). Two-thirds (fourteen) of the twenty-one fractures occurred in the medial malleolus.

CONCLUSIONS

The prevalence of periprosthetic fractures following primary total ankle replacement was relatively low. We propose a classification system for these fractures that is based on more than 500 cases. We believe that this classification can facilitate therapeutic decision-making, as it allows for differential analysis of the cause and guides the choice among operative and nonoperative treatment options.

Incidence of revision after primary implantation of the Scandinavian Total Ankle Replacement system: a systematic review

Total ankle replacement was initially popularized in the 1970s as an alternative to ankle arthrodesis for advanced ankle arthritis; however, failures were catastrophic. Current implants show promise, focusing on normal joint anatomy and function with greatly improved materials and more precise surgical technique. Nevertheless, even with advancements in technology and implant engineering, implant failure remains a problem. Debate has existed and published reports vary greatly concerning the incidence of failure and revision of the Scandinavian Total Ankle Replacement system. Thus, a systematic review was performed revealing a 10.7% revision rate at weighted mean follow-up of 64 months.