Evaluation and management of the painful total ankle arthroplasty

Accuracy of patient-specific instrumentation for implant positioning in custom-made total ankle arthroplasty

Purpose

This retrospective radiological analysis aimed to assess the accuracy of implant positioning in patients with ankle arthritis undergoing custom-made total ankle arthroplasty (TAA) with patient-specific instrumentation (PSI) compared with preoperative planning.

Methods

Patients who underwent custom-made TAA with PSI from January 2018 to March 2023 were retrospectively evaluated, focusing on the tibial anterior surface (TAS) angle, tibial lateral surface (TLS) angle and tibiotalar ratio (TTR). Additionally, data regarding the time from the preoperative computed tomography (CT) scan to surgery, associated procedures and complications were recorded.

Results

No associated procedures were performed, and only one intraoperative complication, an iatrogenic lateral malleolar fracture, was recorded. In the coronal plane, custom-made TAA with PSI consistently achieved precise positioning of prosthetic components, even in cases with significant preoperative deformities or bone deficits. However, a statistically significant deviation from the planned values was observed in the sagittal plane (p = 0.007). A notable correlation was identified between the time elapsed from the preoperative CT scan to surgery and the deviation from the planned to the actual postoperative TAS angle (p < 0.001).

Conclusion

This study underscores the efficacy of PSI systems in achieving precise positioning in the coronal plane, in accordance with preoperative planning. In contrast, sagittal plane positioning did not demonstrate the same level of accuracy, as evidenced by a statistically significant difference between the planned and postoperative TLS values. Nevertheless, all measurements remained within the recommended range according to the existing literature.

Level of Evidence

Level IV.

Diagnosis and Management of Infected Total Ankle Replacements

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

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

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

SPECT/CT of Total Ankle Arthroplasty

Use of SPECT/CT (Single Photon Emission Computed Tomography/Computed Tomography) is increasing providing additional information in patients with inconclusive clinical examination and unremarkable imaging findings presenting with chronic pain after total ankle arthroplasty. To differentiate the cause of pain after total ankle arthroplasty can be challenging. SPECT/CT combines structural and metabolic imaging as a hybrid tool leading to higher specificity and overall diagnostic accuracy presumably in cases of gutter impingement, prosthetic loosening, and osteoarthritis of adjacent joints. Moreover, SPECT/CT can complement diagnostic work up in periprosthetic joint infections. Basal tracer enhancement has to be considered for the interpretation of imaging findings.

Use of Femoral Head Allograft for Extended Bone Loss in Revision Total Ankle Arthroplasty: A Case Report

CASE

A 38-year-old male patient presented with severe ankle pain 13 years after a total ankle arthroplasty (TAA). Radiographic evaluation revealed loosening of the implant and extensive osteolytic lesions. The medial tibial plafond and malleolus were reconstructed using a fresh-frozen femoral head graft, and revision TAA was performed. The midterm results were satisfactory, with adequate integration of the allograft and stable implant components.

CONCLUSION

The use of the allograft technique in revision TAA is feasible in the presence of severe bone loss, including the malleoli, and allows firm component fixation of the reconstructed bone.

Management of Periprosthetic Bone Cysts After Total Ankle Arthroplasty

Modern improvements in total ankle arthroplasty (TAA) have increased the performance of this procedure for treatment of end-stage ankle arthritis. A common finding after TAA is the formation of periprosthetic bone cysts, which can be clinically silent or result in TAA failure. The exact cause of periprosthetic bones cysts has not been established, but major theories are related to osteolysis secondary to implant wear, micromotion, and stress shielding. Treatment can be nonoperative with clinical observation for small, asymptomatic cysts. Large, progressive, and symptomatic cysts often merit surgical treatment with debridement and grafting, revision TAA, or salvage arthrodesis.

Predicting post-total ankle arthroplasty walking speed based on preoperative gait mechanics

Decreased walking speed is associated with impaired physical performance and function in older adults. Following total ankle arthroplasty (TAA), walking speed continues to be slower than age matched controls. The purpose of this study was to determine if patients 1 year post-TAA can achieve walking speed benchmarks and investigate if gait metrics are predictive of achieved benchmarks. 191 TAA patients were recruited and assessed pre-TAA and 1 year post-TAA. Kinetic and kinematic data were collected during seven self-selected speed barefoot walking trials along a 30-m walkway. Receiver operator curves were generated for each variable to determine threshold values needed to achieve walking speeds of 0.8, 0.9, 1.1, and 1.3 m/s. Each variable's predictive ability was classified according to the area under the curve. Ninety one percent of participants achieved a walking speed > 0.8 m/s, 85.3% achieved ≥0.9 m/s, 64.9% walked at ≥1.1 m/s, and 24.1% achieved a walking speed of 1.3 m/s by 1 year post-TAA. Walking speed pre-TAA was the strongest predictor with ankle moment, power and GRF data showing mixed results. Clinical Significance: 75.9% of participants were unable to walk at 1.3 m/s-a speed indicative of safely crossing a street. Variables predictive of postoperative walking speed benchmarks could be useful in developing interventions for the TAA population. The strongest predictor across all walking speed benchmarks was preoperative walking speed. A walking speed > 0.71 m/s was predictive of achieving 0.8 m/s 1 year post-TAA, while >1.09 m/s predicted 1.3 m/s 1 year post-TAA.

Post-operative management after total ankle arthroplasty: A systematic review of the literature

BACKGROUND

Currently, there is no consensus on the most appropriate post-operative management for patients undergoing total ankle arthroplasty. The aim of this study is therefore to offer a systematic review of the pertaining literature to identify current post-operative protocols and describe possible differences.

METHODS

A systematic review to identify recent studies concerning the post-operative management after total ankle arthroplasty was conducted. Five topics were analyzed: length of hospital stay, type and duration of immobilization, weight-bearing management, post-operative pharmacological therapies, adopted rehabilitation scheme.

RESULTS

Eighty-four studies met the inclusion criteria and were included in the review process. Most of the papers appear to have conflicting opinions with no consensus and homogeneous protocols.

CONCLUSION

Due to various methodological limitations, it is not possible to provide sufficiently supported evidence-based recommendations, and it is therefore difficult to determine the superiority of one post-operative protocol over the others after total ankle arthroplasty.

CT Scan Assessment and Functional Outcome of Periprosthetic Bone Grafting After Total Ankle Arthroplasty at Medium-term Follow-up

BACKGROUND

Periprosthetic cysts can occur in up to 95% of total ankle arthroplasties (TAA) and have been correlated with implant failure. The aim of this study was to determine the clinical and radiologic outcomes, using computed tomographic (CT) scan, after periprosthetic cyst bone grafting and assess for the minimum cyst size that should be grafted.

METHODS

A retrospective review was performed of all TAA procedures performed between 2007 and 2014 (n=93). A CT scan was done to assess cyst size and operative planning. Eight patients with 9 periprosthetic cysts larger than 1.75 cm³ were grafted and specimens sent for histology. The mean time to bone grafting was 7.3 (3.8-9.5) years. Functional outcome was assessed using the American Orthopaedic Foot & Ankle Society ankle score, visual analog scale, and Self-reported Foot and Ankle Score. A CT scan was performed at follow-up to assess graft incorporation and cyst size progression. The mean time to CT scan post grafting was 3.0 (0.7-4.7) years.

RESULTS

There was no implant malalignment identified and no differences in the pre- and postoperative functional scores. Preoperatively cysts had a mean volume of 8.16 (2.04-14.03) cm³. The mean percentage incorporation was 89% (69%-100%). Eight of the grafted cysts were considered successful on CT, with the ninth having 69% incorporation. Five cysts were not grafted, as they were below 1.75 cm³, and remained the same size or had minimal enlargement.

CONCLUSION

The satisfactory results in this small cohort suggests that prophylactic bone grafting may extend implant survival. We recommend that periprosthetic cysts greater than 1.75 cm³ be prophylactically bone grafted, and that cysts smaller than 1.75 cm³ be monitored for progression in size.

LEVEL OF EVIDENCE

Level IV, Case Series.

Evaluating and Managing the Painful Total Ankle Replacement

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

Pathogenesis, Evaluation, and Management of Osteolysis Following Total Ankle Arthroplasty

Periprosthetic osteolysis is a common occurrence after total ankle arthroplasty (TAA) and poses many challenges for the foot and ankle surgeon. Osteolysis may be asymptomatic and remain benign, or it may lead to component instability and require revision or arthrodesis. In this article, we present a current and comprehensive review of osteolysis in TAA with illustrative cases. We examine the basic science principles behind the etiology of osteolysis, discuss the workup of a patient with suspected osteolysis, and present a review of the evidence of various management strategies, including grafting of cysts, revision TAA, and arthrodesis.Level of Evidence: Level V, expert opinion.

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.

Arthrofibrosis of the Ankle

Arthrofibrosis is a common, but often overlooked, condition that imparts significant morbidity following injuries and surgery to the foot and ankle. The most common etiologies are related to soft tissue trauma with subsequent fibrotic and contractile scar tissue formation within the ligaments and capsule of the ankle. This leads to pain, alterations in gait, and ankle dysfunction. Initial treatment often includes extensive physical therapy, however, if severe enough surgical options exist. Although the literature regarding ankle arthrofibrosis is scarce, this review article provides a greater understanding of the pathogenesis of arthrofibrosis and describes the current and future therapeutic options to treat fibrotic joints. Level of Evidence: Level V, expert opinion.

Total ankle arthroplasty

For end-stage ankle arthritis, either arthrodesis or total ankle arthroplasty is a available surgical option. With the failure of earlier generation of arthroplasty, arthrodesis has been the gold standard. However, there are some considerable weaknesses of the arthrodesis. Current total ankle arthroplasty is presently an effective surgical treatment for endstage ankle arthritis with much improvement. The goals of surgery are to decrease pain, preserve range of motion, and eventually improve the patient’s quality of life. Recent literatures on total ankle arthroplasty havs shown successful long-term clinical results due to the innovation of second-generation implants, including more anatomic concepts and designs. For successful outcomes, a thorough evaluation of the entire lower limb alignment, deformities of the foot and ankle, and proper selection of patients are very important. Nevertheless, complications, such as wound problems, osteolysis, gutter pain or impingement, infection, loosening, and others, may occur. In this review, we provide a summary of the current research on total ankle arthroplasty.

Clinical-radiological outcomes and complications after total ankle replacement through a lateral transfibular approach: a retrospective evaluation at a mid-term follow-up

PURPOSE

Degenerative ankle arthropathy is a debilitating and increasingly widespread condition with worsening of quality of life. In last years, total ankle replacement has increased indications, thanks to advances in surgical technique, materials and design that provided new solutions for surgeons. The purpose of this study is to evaluate the effectiveness of total ankle replacement (TAR), implanted using a trans-fibular lateral approach in patients with high-grade degenerative arthropathy, in terms of clinical, functional and radiological outcomes and possible complications.

METHODS

This retrospective study included 73 patients, aged between 47 and 79 years (mean age 61.7 ± 14.2 years), who underwent trans-fibular total ankle arthroplasty. All patients were followed up for at least two years post-operatively with mean follow-up 31.2 ± 8.1 months and have been evaluated clinically and radiographically both pre-operatively and post-operatively.

RESULTS

Patients demonstrated a significant improvement in average AOFAS score, SF-36 score and VAS scale. Average plantarflexion improved from 9.9° ± 4.2 to 18.4° ± 6.3 and dorsiflexion from pre-operative mean value of 6.8° ± 5.8 to 17.2° ± 3.1 post-operative. Complications recorded in our series were 16 (21.9%), specifically 2 major complications and 14 minor complications.

CONCLUSIONS

This study found that trans-fibular total ankle replacement is a safe and effective option for patients with ankle osteoarthritis, resulting in improvement of patient-reported outcomes, range of motion, and radiographic parameters. However, further studies are required to determine long-term performance of these implants.

What Tests Are Useful to Investigate a Possible Infection of Total Ankle Arthroplasty (TAA)? What Are Their Thresholds?

RECOMMENDATION

Overall, the approach to a potentially infected total ankle arthroplasty (TAA) does not change compared to other periprosthetic joint infections (PJIs). There are no novel or unique diagnostic procedures for TAA infection, specifically. Joint aspiration or intraoperative tissue/synovial biopsies with microbiological cultures are the most important diagnostic tests for suspected TAA infections. In the absence of specific data related to TAA, the threshold for these tests should be derived from the hip and knee PJI literature.

LEVEL OF EVIDENCE

Strong.

DELEGATE VOTE

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

Does Deep Chronic Infection After Total Ankle Arthroplasty (TAA) Require Implant Removal?

RECOMMENDATION

Yes. Deep chronic infection after total ankle arthroplasty (TAA) requires implant removal unless otherwise contraindicated.

LEVEL OF EVIDENCE

Strong.

DELEGATE VOTE

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

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

RECOMMENDATION

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

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

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

What Is the Optimal Protocol for Performing Debridement, Antibiotics and Implant Retention (DAIR) in an Infected Total Ankle Arthroplasty (TAA) (Type and Volume of Irrigation Solution, and so on)?

RECOMMENDATION

Debridement, antibiotics, and implant retention (DAIR) in acute total ankle arthroplasty (TAA) infections may be an acceptable treatment option. If performed, DAIR should be done meticulously, ensuring that all necrotic or infected tissues are removed and modular parts of the prosthesis, if any, exchanged. The infected joint should also be irrigated with antiseptic solutions.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

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

Should Culture Samples Be Taken During All Revision Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

We recommend that intraoperative cultures be taken during revision total ankle arthroplasty (TAA). The result of intraoperative cultures should be interpreted together with clinical suspicion for infection and the results of the laboratory and imaging investigations. We also recommend that multiple tissue specimens be collected. Given a lack of evidence for routine intraoperative cultures for revision TAA literature, this recommendation is based on analogous evidence in the total hip and knee replacement literature.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

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

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

Background:

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

Methods:

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

Results:

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

Conclusions:

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

Level of Evidence:

Level III, systematic review.

Management of Posttraumatic Ankle Arthritis: Literature Review

PURPOSE OF REVIEW

Trauma is the principle cause of osteoarthritis in the ankle, which is associated with significant morbidity. This review highlights the current literature for the purpose of bringing the reader up-to-date on the management of posttraumatic ankle arthritis, describing treatment efficacy, indications, contraindications, and complications.

RECENT FINDINGS

Recent studies on osteoarthritis have demonstrated variability among anatomic locations regarding the mechanisms and rates of development for posttraumatic osteoarthritis, which are attributed to newly discovered biological differences intrinsic to each joint. Regarding surgical management of posttraumatic ankle arthritis, osteochondral allograft transplantation of the talus, and supramalleolar osteotomies have demonstrated promising results. Additionally, the outpatient setting was found to be appropriate for managing pain following total ankle arthroplasty, associated with low complication rates and no readmission. Management for posttraumatic ankle arthritis is generally progressive. Initial treatment entails nonpharmacologic options with surgery reserved for posttraumatic ankle arthritis refractory to conservative treatment. Patient demographics and lifestyles should be carefully considered when formulating a management strategy, as outcomes are dependent upon the satisfaction of each set of respective criteria. Ultimately, the management of posttraumatic ankle arthritis should be individualized to satisfy the needs and desires, which are specific to each patient.

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.

[Progress of total ankle arthroplasty for end-stage ankle osteoarthritis]

Objective

To review the progress of total ankle arthroplasty (TAA) in treatment of end-stage ankle osteoarthritis (AOA).

Methods

The domestic and foreign literatures about TAA in recent years were reviewed. The current status and progress of TAA were summarized from the results of traditional and computer-assisted TAA clinical outcomes.

Results

End-stage AOA often leads to severe pain and dysfunction, and arthrodesis is still the main selective treatment option. In recent years, with the advancement of surgical techniques and prosthesis design, TAA which can remain joint mobility has increased gradually, and the surgical results also have significant progress. Accurate prosthesis implant and mechanical alignment restoration are critical factors for TAA, and surgery-related malalignment is correlative to the prosthesis failure. Computer assisted patient-specific guide can simplify the TAA procedures and obtain the accuracy of tibia and talus osteotomy.

Conclusion

The clinical efficiency of preoperative CT based patient-specific guide technology for TAA needs further clinical follow-up. Meanwhile, it is necessary to further develop intraoperative navigation and robotic surgery system suitable for TAA.

Computed Navigation Guidance for Ankle Replacement in the Setting of Ankle Deformity

Total ankle replacement (TAR) has evolved over the past decade as a treatment for end-stage ankle arthritis with improved survivorship. Despite the improving outcomes, ankle deformity represents a challenge to the foot and ankle surgeon with increased risk of implant failure. The use of preoperative computer-assisted guidance has led to better understanding the 3-dimensional ankle anatomy and associated deformities and allows for reproducible, anatomic placement of the TAR components.

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.

Can a Three-Component Prosthesis be Used for Conversion of Painful Ankle Arthrodesis to Total Ankle Replacement?

BACKGROUND

In patients with painful ankle arthrodesis, the surgical treatment is challenging, and may include takedown of ankle arthrodesis and conversion to a total ankle replacement (TAR). This procedure is technically demanding given the altered anatomy after arthrodesis. Few studies have evaluated TAR in the setting of prior arthrodesis.

QUESTIONS/PURPOSES

(1) What intraoperative and perioperative complications were observed in patients who underwent conversion of an ankle arthrodesis to a TAR? (2) Was durable fixation achieved at short term, and what was the alignment of the components? (3) What subsequent surgical procedures were performed, including revisions? (4) What improvements were observed in pain, tibiotalar range of motion (ROM), and quality of life?

METHODS

Between January 2007 and December 2014, 18 patients with a painful ankle arthrodesis underwent conversion to TAR at our tertiary referral center. During this period, the indications for conversion of ankle arthrodesis to TAR were tibiotalar nonunion or malunion after attempted arthrodesis in patients who declined revision ankle arthrodesis. The goal of revision surgery was to help patients regain hindfoot mobility and to decrease pain. During the study period, all patients who met indications were treated with a conversion procedure. Of the 18 patients included, 14 were men and four were women. The mean age of the patients was 51 ± 7 years. The mean followup was 54 ± 27 months, with no loss to follow up observed. The initial ankle arthrodesis was performed 6 ± 3.5 years before conversion to TAR. In all patients, the conversion to TAR was performed using a nonconstrained cementless three-component prosthesis. Intraoperative and postoperative complications, revision procedures, and prosthesis component loosening were evaluated. Weightbearing radiographs were used to determine the angular alignment of the tibial and talar components using α/β/γ angles and to analyze the bone-implant interface. Osseointegration was defined as visible trabecular structures at the bone-implant interface without radiolucent lines. The criteria for radiographic loosening was defined as subsidence or migration of prosthesis components and/or a cystic lesion with a diameter at least 2 mm. Clinical assessment included pain evaluation, measurement of ankle ROM, and quality of life.

RESULTS

Two of the 18 patients sustained an intraoperative medial malleolar fracture. In three patients, delayed wound healing was observed. At latest followup, four patients had incomplete osseointegration (posterior quarter of the bone-prosthesis interface on the tibial side). None of the 18 patients had prosthesis loosening. In all patients, both components were neutrally aligned. Two patients had painful arthrofibrosis with reduced ROM, which we treated with an open arthrolysis and exchange of mobile-bearing inlay; one other patient is considering a revision for substantial tibial component medial tilt with collapse of the medial arch. At the latest followup, the mean dorsiflexion and plantar flexion were 8.5° ± 3° and 15° ± 5°, respectively. The mean visual analog scale (VAS) score decreased from 9 ± 0.8 to 1.7 ± 1.6 (p < 0.001). The Short Form Health Survey questionnaire (SF-36) physical and mental outcome scores improved from 34 ± 5 to 74 ± 11 (p < 0.001) and from 49 ± 4 to 75.5 ± 7 (p < 0.001).

CONCLUSIONS

Conversion of an ankle arthrodesis to a TAR is a technically challenging procedure. In this small series, it was associated with frequent complications including arthrofibrosis, and functional outcomes including postoperative ROM were lower than reported for primary TAR. However, pain and function did improve. Further studies are necessary to address long-term clinical and radiographic outcomes in this patient cohort.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

[Aseptic loosening of total ankle replacement : One-stage revision ankle arthroplasty]

OBJECTIVE

To revise one or both loosened prosthesis components, to achieve postoperative pain relief, and preserve ankle range of motion.

INDICATIONS

Aseptic loosening of the tibial and/or talar ankle prosthesis components without substantial bone defect of the tibial or talar bone stock.

CONTRAINDICATIONS

General surgical or anesthesiological risks, infections, critical soft tissue conditions, nonmanageable hindfoot instability, neurovascular impairment of the lower extremity, neuroarthropathy (e. g. Charcot arthropathy), substantial nonreconstructable osseous defects with or without cysts on the tibial and/or talar side, non-compliance, patients with primary total ankle replacement (TAR) using intramedullary fixation (stem fixation), patients with severely reduced bone quality, insulin-dependent diabetes mellitus, smoking, unrealistic patient expectations, patients with high activity in sports.

SURGICAL TECHNIQUE

Exposure of the ankle joint using the previous incision (anterior or lateral transfibular approach). Mobilization and removal of loosened prosthesis component. Careful debridement of bone stock at bone-prosthesis interface. Determination of prosthesis component size. Implantation of definitive prosthesis components. Wound closure in layers.

POSTOPERATIVE MANAGEMENT

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

RESULTS

Between January 2007 and December 2012 a one-stage revision TAR was performed in 14 patients with a mean age of 52.7 ± 12.0 years (29.8-70.5 years). The indication for revision surgery was aseptic loosening of one or both prosthesis components. The mean time between the initial TAR and revision surgery was 5.9 ± 2.9 years (2.0-11.5 years). In 2 patients a tibiotalocalcaneal arthrodesis was performed due to painful aseptic loosening of revision TAR. In all patients a significant pain relief was observed.

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

OBJECTIVE

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

INDICATIONS

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

CONTRAINDICATIONS

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

SURGICAL TECHNIQUE

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

POSTOPERATIVE MANAGEMENT

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

RESULTS

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

The painful total ankle arthroplasty: a diagnostic and treatment algorithm

The last decade has seen a considerable increase in the use of in total ankle arthroplasty (TAA) to treat patients with end-stage arthritis of the knee. However, the longevity of the implants is still far from that of total knee and hip arthroplasties. The aim of this review is to outline a diagnostic and treatment algorithm for the painful TAA to be used when considering revision surgery. Cite this article: Bone Joint J 2017;99-B:5-11.

Surgical Treatment of Bony and Soft-Tissue Impingement in Total Ankle Arthroplasty

BACKGROUND

Impingement may be an underreported problem following modern total ankle replacements (TARs). The etiology of impingement is unclear and likely multifactorial. Because of the lack of conservative treatment options for symptomatic impingement after TAR, surgery is often necessary.

METHODS

We retrospectively identified a consecutive series of 1001 primary TARs performed between January 1998 and December 2014. We identified patients who required a secondary surgery to treat soft-tissue and bony impingement by either an open or arthroscopic procedure. Functional and clinical outcomes, including secondary procedures, infections, complications, and failure rates, were recorded.

RESULTS

In all, 75 patients (7.5%) required either open (n = 49) or arthroscopic debridement for impingement after TAR; 44 patients had >12 months of follow-up, with a follow-up of 26.5 months after their debridement procedure. The mean time to the debridement procedure for all prostheses was 29.3 months, with an average of 38.7 months in STAR, 21.8 months in INBONE, and 10.5 months in Salto Talaris patients. Of the patients with more than 1 year's follow-up from their debridement, 84.1% were asymptomatic; 9 patients (20.4%) had repeat operations after their debridement procedure. Of these, 5 patients required a repeat debridement of their medial or lateral gutters for a failure rate of 11.4%.

CONCLUSION

Both arthroscopic and open treatment of impingement after total ankle arthroplasty are safe and effective in improving function and pain. Although the rates for revision impingement surgery are higher in arthroscopic compared with open procedures, they are not significantly so. Therefore, we recommend arthroscopic surgery whenever possible because of earlier time to weight bearing and mobility.

LEVELS OF EVIDENCE

Level IV.

Iatrogenic Arteriovenous Fistula With Associated Pseudoaneurysm of Posterior Tibial Artery After Revision Total Ankle Arthroplasty: A Case Report

Iatrogenic vascular injuries in elective orthopedic surgery are rare. However, these are important complications to recognize early and treat appropriately because the potential sequelae can be devastating. Arteriovenous fistula of the lower extremity after total ankle arthroplasty has not been previously described in published studies. The proper diagnosis of arteriovenous fistulas can be difficult without a high index of suspicion, and treatment often involves surgical intervention. We present the case of a 62-year-old male who developed an iatrogenic arteriovenous fistula with associated pseudoaneurysm of the posterior tibial artery after revision total ankle arthroplasty that was treated with surgical ligation and excision, followed by reverse saphenous vein grafting.

Effect of Obesity on Total Ankle Arthroplasty Outcomes

BACKGROUND

The purpose of this study was to evaluate the effect of obesity on intermediate- to long-term implant failure rates and survivorship after total ankle arthroplasty.

METHODS

A chart review was performed for all patients who underwent primary total ankle arthroplasty between 2004 and 2009 with a minimum 5-year follow-up. Patients were separated into a reference group with a body mass index less than 30 kg/m2 and an obese group with an index greater than or equal to 30 kg/m2. Minimum 5-year follow-up outcomes were available for 49 patients in the obese group and 48 patients in the nonobese group. Mean follow-up was 8.2 ± 2.0 years (range, 5.1-11.5 years) in the reference group and 7.7 ± 2.0 years (range, 5.0-11.9 years) in the obese group (P = .26).

RESULTS

Based on multivariable logistic regression, obese patients had a significantly greater probability of implant failure by final follow-up (adjusted odds ratio, 2.8 [95% CI, 1.04-7.53]; P = .04). Cox regression analysis of 5-year implant survivorship showed no significant difference between the 2 groups (adjusted hazard ratio, 1.89 [95% CI, 0.77-4.65]; P = .17). When compared with obese patients with inflammatory or posttraumatic arthritis, obese patients with osteoarthritis demonstrated a significantly decreased 5-year survivorship (adjusted hazard ratio, 3.73 [95% CI, 1.05-10.43]; P = .04).

CONCLUSION

This study demonstrated an increased long-term risk of implant failure among obese patients that was not seen in the intermediate term. Furthermore, obese patients with primary osteoarthritis were found to have a significantly decreased 5-year implant survivorship after ankle arthroplasty as compared with obese patients with inflammatory or posttraumatic arthritis and therefore should be counseled appropriately when deciding between arthroplasty and arthrodesis.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Radiographic Outcomes of Preoperative CT Scan-Derived Patient-Specific Total Ankle Arthroplasty

BACKGROUND

Preoperative computer navigation and patient-specific instrumentation have had promising results in total knee arthroplasty and in a previous cadaveric total ankle arthroplasty (TAA) study. Potential benefits of patient-specific guides include improved implant alignment and decreased surgical time. The purpose of this retrospective case series was to evaluate the accuracy, reproducibility, and limitations of TAA tibia and talar implant placement and radiographic alignment using preoperative computed tomography (CT) scan-derived instrumentation in a clinical setting.

METHODS

Between 2012 and 2014, 42 consecutive TAA cases in 42 patients using preoperative CT scan-derived patient-specific plans and guides (PROPHECY, Wright Medical Technology, Memphis TN) were reviewed from a single center of foot and ankle fellowship-trained orthopaedic surgeons. TAA implants used included 29 intramedullary referencing implants (INBONE II, Wright Medical Technology) and 13 low-profile tibia and talar resurfacing implants (Infinity, Wright Medical Technology). All patients had standardized preoperative CT scans before surgery that were used to create custom surgical plans and 3-dimensional solid cutting guides and models. All patients had a minimum 3-month follow-up with weightbearing postoperative radiographs. Patient demographics were recorded, and coronal and sagittal alignments were compared among weightbearing preoperative radiographs, CT scan-derived surgical plans, and weightbearing postoperative radiographs using a digital picture archiving and communication system.

RESULTS

Average age for all patients was 63 ± 9 years, with a body mass index of 29.8 ± 5.9. Average total surgical time for all TAAs was 100 ± 11 minutes, with Infinity TAAs taking less time than INBONE II TAAs (92 vs 104 minutes; P < .05). Average preoperative coronal alignment was 1.9 degrees varus ± 6.4 (range, 14 degrees valgus to 10 degrees varus). Postoperative weightbearing alignments for all TAA cases were within ±3° of the predicted coronal and sagittal alignments from the CT scan-derived surgical plans. There were no significant differences in pre- or postoperative weightbearing alignments between INBONE II and Infinity TAA cases. Neutral coronal and sagittal alignments were obtained for all TAA cases regardless of preoperative deformity. Patient-specific surgical plans were accurate to within 1 size for tibia and talar implants used. Surgical plans predicted the actual tibia implant size used in 100% of INBONE II cases and 92% of Infinity cases. Plans were less accurate for talar implants and predicted the actual talar implant size used in 76% of INBONE II cases and 46% of Infinity cases. In all cases of predicted tibia or talar size mismatch, surgical plans predicted 1 implant size larger than actually used.

CONCLUSIONS

Results from this study provide early clinical evidence that preoperative CT scan-derived patient-specific surgical plans and guides can help provide accurate and reproducible TAA radiographic alignments. Talar implant sizing was not as accurate due to individual surgeon preference regarding the extent of gutter debridement. Similar to other modern computer navigation and patient-specific instrumentation systems, final coronal and sagittal alignments were within 3 degrees of the predicted surgical plans, and sizing was accurate within 1 implant size. Future studies are warranted to investigate the clinical and functional implications of patient-specific TAA and the overall cost-effectiveness of this technique.

LEVEL OF EVIDENCE

Level IV, retrospective case series.