Use of a trabecular metal implant in ankle arthrodesis after failed total ankle replacement

Custom Patient-Specific 3D-Printed Titanium Truss Tibiotalocalcaneal Arthrodesis Implants for Failed Total Ankle Replacements: Classification, Technical Tips, and Treatment Algorithm

BACKGROUND

The management of failed total ankle replacements, with significant loss of bone stock, is challenging with high rates of complications and associated morbidity. Recent technological advances have enabled the development of patient-customized 3D-printed titanium truss arthrodesis implants, which offer an alternative salvage option for failed total ankle replacements.

METHODS

A prospective observational study was performed of 6 cases of failed total ankle replacements that were managed using custom patient-specific 3D-printed titanium truss arthrodesis implants. Technical tips, classification, and a treatment algorithm were developed based on our initial experience.

RESULTS

Between November 2018 and March 2022, 6 patients underwent arthrodesis for failed total ankle replacements. Follow-up was available for all cases. The mean follow-up was 3.0 years (range 1-4.5). The mean MOXFQ Index improved from 73.1 to 32.3 (P < .05). The mean EQ-5D-5L Index improved from 0.366 to 0.743 (P < .05) and the EQ-VAS also improved from 53.0 to 63.3 (P = .36). The mean VAS-Pain score at final follow-up was 27.5. There were no cases of nonunion. None of the patients were smokers. The overall complication rate was 50%. Two patients returned to surgery: one for wound washout following TAR explantation and a second for removal of metalwork 2 years following surgery for a prosthetic joint infection secondary to hematogenous spread. No patients underwent revision fixation or amputation.

CONCLUSION

Custom patient-specific 3D-printed titanium truss arthrodesis implants are a viable treatment option for failed total ankle replacements.

Revision Total Ankle Arthroplasty Using the INBONE II System

BACKGROUND

The utilization of total ankle arthroplasty (TAA) for managing severe ankle osteoarthritis has become increasingly common, leading to a higher occurrence of revision TAA procedures because of failure of primary TAA. This study aims to examine the clinical results associated with revision TAA using the INBONE II system. Given the growing number of TAA revision procedures and a focus on motion-preserving salvage options, we evaluated our early experience with revision TAA.

METHODS

A retrospective analysis was conducted on a group of 60 presumed noninfected patients who underwent revision TAA with the INBONE II system. Detailed information was collected on patient demographics, implant characteristics, concurrent procedures, and complications. The implant survival was estimated using Kaplan-Meier analysis.

RESULTS

The study revealed high complication rates but generally fair clinical outcomes for revision TAA using the INBONE II system. Complications were observed in 22 patients (36.7%), including persistent pain (n = 6), nerve injury/impingement (n = 5), infection (n = 3), fracture (n = 3), implant failure (n = 3), impaired wound healing (n = 2), and osteolysis (n = 3). The 3-year survivorship rate from reoperation was 92.0% (82.7%-100.0%) whereas the 3-year survivorship rate from major complications was 90.4% (80.8%-100.0%).

CONCLUSION

We report high complication rates but generally fair clinical results for revision TAA utilizing the INBONE II system.

Revision Total Ankle Arthroplasty Using a Novel Modular Fixed-Bearing Revision Ankle System

INTRODUCTION

Large bone defects such as those encountered after failed total ankle replacement have previously been a relative contraindication to revision ankle replacement due to inadequate bone stock. We describe our experience and patient reported outcomes with a modular ankle replacement system with tibial and talar augments.

METHODS

This is a retrospective case series analysis of patients who underwent a total ankle replacement using the INVISION system across 2 centers between 2016 and 2022. Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Ankle Osteoarthritis Scale (AOS), and EQ-5D pre-operatively and then post-operatively at 6 months, 1 year, 2 years, 3 years, and 5 years. Medical records were reviewed for complications and re-operations. X-rays were reviewed for lucencies and alignment.

RESULTS

A total of 17 patients were included in the study; 14 men and 3 women with an average age at the time of surgery of 67.9 years (range 56-80 years). The average follow-up post-operatively was 40.5 months (range 7-78) at the time of this study. The indication for surgery was revision of failed total ankle replacement (TAR) in 16 and revision of failed ankle fusion in 1. An augmented tibia was used in 13, an augmented talus in 13, and both augmented tibia and talus in 9 cases. There were no early surgical complications. One patient required debridement and implant retention for late deep infection. No implants have been revised. The average MOXFQ score improved by 19.3 points at most recent follow-up. The average AOS score improved by 25.2 points.

CONCLUSION

The early results of a modular augmented ankle arthroplasty system have shown satisfactory patient outcomes with a low complication and re-operation rate and present another option for patients with larger bone defects. This is a small series, and a larger series with long-term follow-up would be beneficial.

LEVELS OF EVIDENCE

Level IV: Case series.

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.

The outcomes of revision surgery for a failed ankle arthroplasty

Aims

Revision rates for ankle arthroplasties are higher than hip or knee arthroplasties. When a total ankle arthroplasty (TAA) fails, it can either undergo revision to another ankle replacement, revision of the TAA to ankle arthrodesis (fusion), or amputation. Currently there is a paucity of literature on the outcomes of these revisions. The aim of this meta-analysis is to assess the outcomes of revision TAA with respect to surgery type, functional outcomes, and reoperations.

Methods

A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Medline, Embase, Cinahl, and Cochrane reviews were searched for relevant papers. Papers analyzing surgical treatment for failed ankle arthroplasties were included. All papers were reviewed by two authors. Overall, 34 papers met the inclusion criteria. A meta-analysis of proportions was performed.

Results

Six papers analyzed all-cause reoperations of revision ankle arthroplasties, and 14 papers analyzed failures of conversion of a TAA to fusion. It was found that 26.9% (95% confidence interval (CI) 15.4% to 40.1%) of revision ankle arthroplasties required further surgical intervention and 13.0% (95% CI 4.9% to 23.4%) of conversion to fusions; 14.4% (95% CI 8.4% to 21.4%) of revision ankle arthroplasties failed and 8% (95% CI 4% to 13%) of conversion to fusions failed.

Conclusion

Revision of primary TAA can be an effective procedure with improved functional outcomes, but has considerable risks of failure and reoperation, especially in those with periprosthetic joint infection. In those who undergo conversion of TAA to fusion, there are high rates of nonunion. Further comparative studies are required to compare both operative techniques. Cite this article: Bone Jt Open 2022;3(7):596–606.

[Salvage options following failed total ankle arthroplasty]

The number of patients with osteoarthritis of the ankle, which are treated by arthroplasty, has continuously increased in recent years. The survival time of these implants is far below the results following hip and knee arthroplasty. In some cases a failure rate of approximately 1% per year or a survival rate of 70% after 10 years has been reported. The most frequent reasons for revision of an ankle prosthesis are aseptic loosening, technical implantation errors and persisting pain. For the revision of an ankle prosthesis there are basically two treatment options. For a long time, ankle arthrodesis was considered the gold standard after a failed prosthesis. In recent years, there has been an increasing trend towards re-implantation of an ankle prosthesis, as this preserves the functionality and mobility of the ankle joint as far as possible. Depending on the reason for failure and the size of the bony defect, a decision must be made regarding a one-stage and a two-stage procedure with bone augmentation. This article presents the advantages and disadvantages of arthrodesis and revision arthroplasty after failed primary ankle arthroplasty and highlights the special features of surgery.

A 3D-Printed Model of a Titanium Custom-Made Talus for the Treatment of a Chronic Infection of the Ankle

Osteoarticular infections are challenging and difficult to treat. The use of innovative technologies like 3D printing already employed in other types of surgeries and pathologies can suppose a great asset to tackle the problem and improve functional results. We present a case of an osteoarticular infection of an ankle treated with a custom-made titanium talus made with 3D metal printing technology: A 63-year-old patient, with chronic infection of the ankle. A 2-staged surgery was performed, with a hand-made cement spacer used during the first stage and the implantation of a custom-made titanium talus with an arthrodesis nail in the second stage. After a 2-year follow-up, a good clinical evolution was achieved, with no signs of reactivation of the infection, no pain, good skin condition and optimal functionality: functional gait pattern without pain and any external aids.

Use of Three-dimensional Titanium Trusses for Arthrodesis Procedures in Foot and Ankle Surgery: A Retrospective Case Series

Periarticular osseous defects pose a challenge when considering arthrodesis. Failure to restore the cubic content of bone can result in shortening and malalignment, as well as subsequent biomechanical issues. This study reports on 12 patients treated with patient-specific 3-D printed (7) and prefabricated titanium trusses (5). Twelve consecutive patients were treated for osseous defects of the forefoot, hindfoot, and ankle with patient-specific, 3D printed or prefabricated manufacturer titanium trusses. Seven were customized, patient-specific 3D printed trusses (4WEB, Frisco, Texas) and 5 were prefabricated manufacturer titanium trusses. All patients had a minimum of 6 months of clinical and radiographic follow-up. and no patients were lost to follow-up. Seven of the 12 patients had a computed tomography (CT) scan performed following surgery. Successful limb or ray salvage was achieved in 11 of 12 patients (91.7%). Six of 7 patients (85.7%) with a postoperative CT scan, went on to complete radiographic consolidation across all arthrodesis sites. The remaining 5 patients showed complete consolidation across the arthrodesis sites on plain film radiographs. Complications included one patient with a residual midfoot deformity that required a subsequent midfoot osteotomy in order to obtain a plantigrade foot following successful tibiotalocalcaneal (TTC) arthrodesis, and a below knee amputation in one patient who underwent revision TTC arthrodesis to salvage avascular necrosis of the talus that developed following the index procedure. Eleven of 12 patients undergoing arthrodesis demonstrated successful union with both customized, patient-specific 3D printed and prefabricated manufacturer titanium trusses on CT scans or radiographs. The average follow-up was 14 months. Reports on traditional methods of addressing periarticular defects in patients requiring arthrodesis show mixed results and relatively high complication rates. Custom, 3D printed and prefabricated titanium truss technology offers an alternative to traditional methods for large, periarticular osseous defects.

Retrograde nailing, trabecular metal implant and use of bone marrow aspirate concentrate after failed ankle joint replacement

BACKGROUND

Ankle fusion after removal of alloplasty is known to be a procedure with a high potential for non-unions and poor function, especially tibio-talo-calcaneal fusion. We wanted to review our results after using a novel method for the procedure, combining retrograde nailing with a trabecular metal implant and bone marrow aspirate concentration applied in an ostoconductive pad in addition to autologous bone grafting.

MATERIALS AND METHODS

Retrospective review of a patient series, with some prospectively registered data. 31 ankles in 30 patients were operated from January 2016 to February 2019.

RESULTS

There were two non-unions (6.5%), and one delayed union, none of these were reoperated. The mean postoperative Manchester-Oxford Foot and Ankle Questionnaire score (MOxFQ) was 33.6 points. 9 patients scored an average MOxFQ at 72.9 immediately before surgery, while at follow-up this had decreased to 36.2, an improvement of 36.7 points (95% CI 18.3-54.9). There were 1 minor infection and 5 possible nerve injuries. One patient had the leg amputated 1 year after the surgery due to a non-related necrotizing fasciitis.

CONCLUSION

We present reasonably good short to medium term patient satisfaction and fusion rates with this novel combination of techniques.

Revision Surgery for Failed Total Ankle Replacement

Revision surgery for failed total ankle replacement is a challenge to the revision surgeon. Deformity, presence of infection, segmental bone defects, patient comorbidities, and soft tissue compromise all are significant considerations when determining appropriate procedures. Revision total ankle replacement, explant and fusion with or without lengthening, use of a trabecular metal cage, placement of an antibiotic cement spacer, grafting, and amputation all are viable options to treat patients with failed ankle arthroplasty.

Metal trabecular bone reconstruction system better improves clinical efficacy and biomechanical repair of osteonecrosis of the femoral head than free vascularized fibular graft: A case-control study

In this study, we aim to compare and analyze the biomechanical repair and clinical efficacy of osteonecrosis of the femoral head (ONFH) with the use of metal trabecular bone reconstruction system and free vascularized fibular graft. The study enrolled 66 adult patients from medical records of nontraumatic ARCO 2A-3B stage ONFH. A simple ONFH model without surgical treatment was established in 13 cases, 29 cases were treated with metal trabecular bone reconstruction system, and 24 cases were treated with free vascularized fibular graft. Computer-recognized and extracted femur outlines were imported, and three-dimensional reconstructions were performed. The stress concentration and stress peak value were analyzed, and the Harris score, visual analog scale pain score, and operation status of the above patients were compared. Finally, quality of life assessment was performed using SF-36 scale. Metal trabecular bone reconstruction system provided less operation time, blood loss, and the total length of postoperative hospital stay than free vascularized fibular graft. Metal trabecular bone reconstruction system promoted bone reconstruction, increased bone mineral density and Harris score. The total clinical effective rate of young patients (20-40 years) was higher than that of older patients (41-60 years). Metal trabecular bone reconstruction system provided higher physical component summary, mental component summary, and role/social component summary than free vascularized fibular graft. This study demonstrates that both metal trabecular bone reconstruction system and free vascularized fibular graft can prevent or delay the progression of ONFH, while metal trabecular bone reconstruction system is a better choice because of better short-term clinical efficacy.

Large Osseous Defect Reconstruction Using a Custom Three-Dimensional Printed Titanium Truss Implant

Treatment of large osseous defects remains a difficult surgical challenge. Autografts and allografts have been known to undergo late collapse, because these options are not specifically designed to withstand the high loads of the foot and ankle. The inability to achieve the correct shape for reconstruction further limits their application. Large osseous defects will result during salvage after failed Lapidus bunionectomy, explantation of failed total ankle replacements, and nonunion of Evans calcaneal osteotomy. Each of 3 patients received a 4WEB custom 3-dimensional (3D) titanium truss implant (Patient Specific Custom Implant; 4WEB Medical, Inc., Frisco, TX) for reconstruction. The mean follow-up period was 17.33 ± 3.51 months. Significant improvement was seen in pain, with a successful return to activities of daily living. The 12-month postoperative computed tomography findings demonstrated incorporation of the implant to the surrounding cortical and cancellous bone. No signs of delayed complications, such as stress shielding or implant failure, were found. This is the first case series to describe the use of a custom 3D-printed titanium truss implant to successfully contribute to reconstruction in the setting of failed elective foot and ankle surgery. This technology might play an important role in limb salvage of osseous defects that would otherwise require bone block arthrodesis with structural allograft or autograft bone.

Poor outcomes of fusion with Trabecular Metal implants after failed total ankle replacement: Early results in 11 patients

INTRODUCTION

One of the reasons for revision of total ankle replacement (TAR) implants is loosening due to subchondral cysts. Reconstruction and fusion of the ankle is often the first choice for revision procedures due to the large bone defects, which are typically filled with autograft and/or allograft. Filling the defect with a trabecular metal tantalum implant is a potential alternative given the biomechanical properties of this component.

HYPOTHESIS

Using tantalum as a spacer provides primary stability and contributes to fusion of the ankle joint after removal of failed TAR implants.

METHODS

Eleven patients underwent arthrodesis an average of 6.9 years after TAR. The mean height of the bone defect was 32mm. It was filled with a specially designed quadrangular implant (Trabecular Metal™, Zimmer/Biomet) combined with an iliac crest graft. Ten patients underwent tibio-talo-calcaneal (TTC) arthrodesis fixed with an angled retrograde nail and one patient underwent talocrural arthrodesis fixed with two plates (anterolateral and anteromedial). The clinical, functional (AOFAS and SF36 scores) and radiological (plain X-rays and CT scan) outcomes were determined.

RESULTS

At a mean follow-up of 19.3 months, the mean total AOFAS score was 56 (21-78) and the mean SF36 score was 60.5 (19-84). One patient was lost to follow-up and four patients still had pain. The tantalum implant was integrated in six patients. Five patients achieved fusion of the subtalar joint and 8 achieved fusion of the talocrural joint. Three patients required surgical revision.

DISCUSSION

Our hypothesis was not confirmed. The clinical outcomes after more than 1 year of follow-up are disappointing, as was the large number of nonunion cases and the lack of tantalum integration. These technical failures can be explained by insufficient construct stability and/or insufficient implant porosity.

LEVEL OF EVIDENCE

IV (retrospective cohort study).

Revision of Stemmed Agility Implants

Total ankle arthroplasty has advanced rapidly in the last 20 years. Early agility implants enjoyed improved survivability compared with more archaic total ankle implants. When talar subsidence occurs, the revision options include a stemmed component to improve stability by spanning the subtalar joint. Removal and revision of these stemmed components can be difficult because of ingrowth and bone loss.

Technique for Use of Trabecular Metal Spacers in Tibiotalocalcaneal Arthrodesis With Large Bony Defects

There are many causes of large bone defects in the tibiotalar joint that need to be definitively treated with a tibiotalocalcaneal (TTC) arthrodesis. Some of the challenges of a large defect are its effect on leg length and the complications associated with trying to fill the defect with structural bone graft. We present an operative strategy involving the use of a trabecular metal implant, a TTC nail that utilized 2 forms of compression, and Reamer/Irrigator/Aspirator (RIA) autograft, to address limitations of previous operative approaches and reliably treat this operative challenge.

Outcome After Salvage Arthrodesis for Failed Total Ankle Replacement

BACKGROUND

In cases with total ankle replacement (TAR) failure, a decision between revision TAR and salvage arthrodesis (SA) must be made. In a previous study, we analyzed revision TAR and found low functional outcome and satisfaction. The aims of the current study were to analyze SA concerning failure rate and patient-related outcome measures (PROMs).

METHODS

Until September 2014, a total of 1110 primary TARs were recorded in the Swedish Ankle Registry. Of the 188 failures, 118 were revised with SA (and 70 with revision TAR). Patient- and implant-specific data for SA cases were analyzed as well as arthrodesis techniques. Failure of SA was defined as repeat arthrodesis or amputation. Generic and region-specific PROMs of 68 patients alive with a solid unilateral SA performed more than 1 year before were analyzed.

RESULTS

The first-attempt solid arthrodesis rate of SA was 90%. Overall, 25 of 53 (47%) patients were very satisfied or satisfied. Mean Self-reported Foot and Ankle Score (SEFAS) was 22 (95% confidence interval 20-24), Euro Qol-5 Dimensions 0.57 (0.49-0.65), Euro Qol-Visual Analogue Scale 59 (53-64), Short Form-36 physical 34 (31-37) and mental 50 (46-54). The scores and satisfaction were similar to those after revision TAR but the reoperation rate was significantly lower in SA (P < .05).

CONCLUSION

Salvage arthrodesis after failed TAR had a solid arthrodesis rate of 90% at first attempt, but similar to revision TAR, less than 50% of the patients were satisfied and the functional scores were low. Until studies show true benefit of revision TAR over SA, we favor SA for failed TAR.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Vascularized Pedicled Fibula Onlay Bone Graft Augmentation for Complicated Tibiotalocalcaneal Arthrodesis With Retrograde Intramedullary Nail Fixation: A Case Series

Tibiotalocalcaneal arthrodesis stabilized with retrograde intramedullary nail fixation is associated with a high incidence of complications. This is especially true when performed with a bulk structural allograft and poor soft tissue quality. In select high-risk limb salvage cases, we have augmented tibiotalocalcaneal arthrodesis procedures stabilized using retrograde intramedullary nail fixation with a vascularized pedicled fibular onlay bone graft. We present the data from 10 such procedures with a mean follow-up period of 10.9 ± 5.4 (range 6 to 20) months involving 10 patients (9 males and 1 female). The etiology was avascular osteonecrosis of the talus and/or distal tibia and a resultant large volume cavitary bone defect (8 ankles), severe equinocavovarus contracture (1 ankle), and failed total ankle replacement (1 ankle). A frozen femoral head bulk allograft was used twice, a whole frozen talus allograft once, and a freeze-dried calcaneal allograft once. The fibula was mobilized with intact musculoperiosteal perforating branches of the peroneal artery as a vascularized pedicle onlay bone graft fixated with a screw and washer construct. The mean fibular graft length was 10.2 ± 2.3 cm. The mean interval to radiographic fusion was 2.6 ± 0.6 months and to weightbearing was 3.1 ± 1.4 months. Two stable bulk allograft-host bone and fibular graft-host bone nonunions occurred after intramedullary nail hardware failure. Tibiotalocalcaneal arthrodesis augmented by vascularized pedicled fibular graft stabilized with retrograde compression intramedullary nail fixation offers a reliable option for complex salvage situations when few other options exist.

Patient-Specific 3-Dimensional Printed Titanium Truss Cage With Tibiotalocalcaneal Arthrodesis for Salvage of Persistent Distal Tibia Nonunion

Management of large structural defects of the ankle and hindfoot is challenging with modest outcomes in the literature. Tibiotalocalcaneal (TTC) arthrodesis using a retrograde intramedullary nail has been used for the treatment of talar avascular necrosis, severe tibial plafond fractures, ankle and hindfoot nonunions, Charcot arthropathy, and failed total ankle arthroplasty. External fixators and spatial frames provide robust multiplanar correction of deformity, but little is known in the literature regarding the salvage treatment of persistent nonunion refractory to frame treatment. In this report, we present the case of an open tibial plafond fracture with nonunion despite 1 year of fixator and frame management that was successfully treated using a patient-specific 3-dimensional printed titanium truss cage in combination with a retrograde TTC nail. At most recent 1-year follow-up, the patient had minimal pain, no wound complications, and was able to ambulate and work independently without an assistive device for the first time in 2 years since his original injury. The case presented here serves as a proof of principle that requires future research to determine its long-term clinical benefits, cost-effectiveness, and complications.

LEVEL OF EVIDENCE

Level V: Expert Opinion.

Salvage of a Failed Agility Total Ankle Replacement System Associated with Acute Traumatic Periprosthetic Midfoot Fractures

This article presents a rare case involving combined revision of a failed Agility Total Ankle Replacement System (DePuy Orthopaedics, Warsaw, Indiana) and open reduction with internal fixation of periprosthetic midfoot fractures secondary to acute traumatic injury. The rationale for these procedures, the operative sequence of events, and recovery course are presented in detail. Causes for concern regarding subsequent revision, should this be required, are raised.

Management of Massive Hindfoot Osteolysis Secondary to Failed INBONE I Total Ankle Replacement

This article presents a procedure whereby a failed INBONE I saddle talar component and polyethylene insert associated with massive cystic changes within the talus and calcaneus secondary to aseptic osteolysis was treated with impaction cancellous allograft bone graft impregnated with autogenous proximal tibia bone marrow aspirate and conversion to an INBONE II sulcus talar component and polyethylene insert. Concomitantly, a percutaneous tendo-Achilles lengthening and posterior capsule release was performed to enhance ankle dorsiflexion. The rationale for these procedures, the operative sequence of events, and recovery course are presented in detail. Causes for concern regarding subsequent revision, should this be required, are raised.

Isolated Subtalar Distraction Arthrodesis Using Porous Tantalum: A Pilot Study

BACKGROUND

During reconstructive procedures of the hindfoot, a structural graft is often needed to fill gaps. To eliminate donor site morbidity and limited availability of autografts, porous tantalum was used.

METHODS

Eighteen patients who underwent subtalar joint distraction arthrodesis by means of trabecular metal augment were reviewed retrospectively. The results were evaluated clinically, with the American Orthopaedic Foot & Ankle Society (AOFAS) score and the visual analog scale (VAS) for pain, and were assessed radiologically. The mean follow-up period was 18 months.

RESULTS

Computed tomography showed sound fusion. There was a marked increase in AOFAS scores and a decrease in VAS scores. Arthrodesis was achieved in all cases with no major postoperative complications. Radiographically, there was a marked increase in all measured parameters (talocalcaneal angle, talocalcaneal height, talar declination angle), and the intraoperatively achieved correction was maintained at the last follow-up visit.

CONCLUSION

Our data suggest that porous tantalum may be used as a structural graft option for subtalar arthrodesis.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Poor prosthesis survival and function after component exchange of total ankle prostheses

BACKGROUND AND PURPOSE

In failed total ankle replacements (TARs), fusion is often the procedure of preference; the outcome after exchanging prosthetic components is debated. We analyzed prosthetic survival, self-reported function, and patient satisfaction after component exchange. Patients and methods We identified patients in the Swedish Ankle Registry who underwent exchange of a tibial and/or talar component between January 1, 1993 and July 1, 2013 and estimated prosthetic survival by Kaplan-Meier analysis. We evaluated the patient-reported outcome measures (PROMs) SEFAS, EQ-5D, EQ-VAS, SF-36, and patient satisfaction by direct questions.

RESULTS

69 patients underwent revision TAR median 22 (0-110) months after the primary procedure. 24 of these failed again after median 26 (1-110) months. Survival analysis of revision TAR showed a 5-year survival rate of 76% and a 10-year survival of 55%. 29 patients with first revision TAR in situ answered the PROMs at mean 8 (1-17) years after revision and had the following mean scores: SEFAS 22, SF-36 physical 37 and mental 49, EQ-5D index 0.6, and EQ-VAS 64. 15 of the patients were satisfied, 5 were neither satisfied nor dissatisfied, and 9 were dissatisfied.

INTERPRETATION

Revision TAR had a 10-year survival of 55%, which is lower than the 10-year survival of 74% for primary TAR reported from the same registry. Only half of the patients were satisfied. Future studies should show which, if any, patients benefit from revision TAR and which patients should rather be fused directly.

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.

Intermediate-term Results of Mobile-bearing Total Ankle Replacement

BACKGROUND

The literature analyzing total ankle replacement (TAR) results should be critically interpreted because studies made by the design surgeons are potentially subject to bias. European nondesigner surgeon studies reviewing the HINTEGRA TAR system are scarce in the literature. The present study is a European nondesigner surgeon study reviewing a consecutive series of 50 HINTEGRA TAR systems with a minimum follow-up of 2 years, focusing on clinical and radiographic outcomes.

METHODS

Fifty primary TAR procedures were performed between February 2008 and January 2012 by a single surgeon. Every patient underwent a standardized clinical and radiographic follow-up at 6 weeks, 3 and 6 months, and 1 year postoperatively and annually thereafter. The mean time to final follow-up was 45 months.

RESULTS

The mean American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score significantly increased from 43.5 preoperatively to 83.8 postoperatively. Clinical range of motion of the ankle also improved from 23.3 degrees preoperatively to 28.3 degrees postoperatively. In 70% of the TAR procedures, the talar component was positioned anteriorly with respect to the tibial axis. Radiological evidence of osteolysis was identified in 24 ankles. The failure rate in the present series was 10%, which was defined as having major revision surgery within 4 years.

CONCLUSION

The survival of the first 50 HINTEGRA TAR systems in this series was satisfactory from clinical and radiological points of view. However, the incidence of asymptomatic periprosthetic osteolytic lesions was quite high (24 ankles).

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Salvage of failed total ankle replacement using tantalum trabecular metal: case series

BACKGROUND

Although newer generations of total ankle arthroplasty designs have better clinical outcomes, failure due to aseptic loosening remains a frequent major complication. Arthrodesis is the most common salvage procedure for a failed total ankle replacement. There are several arthrodesis techniques each with its advantages and disadvantages. We present a technique of ankle arthrodesis for failed total ankle replacements using tantalum Trabecular Metal™ (Zimmer, Warsaw, IN) with internal fixation, thus sparing the subtalar joint.

METHODS

Three patients who had undergone arthrodesis for a failed total ankle replacement using tantalum Trabecular Metal were retrospectively reviewed. The mean follow-up period was 57 (range, 31-86) months. The mean age at ankle arthroplasty was 57 (range, 33-72) years and at ankle arthrodesis was 63 (range, 44-74) years. The mean time from arthroplasty to arthrodesis was 7 (range, 2-11) years.

RESULTS

The American Orthopaedic Foot and Ankle Society (AOFAS) score improved from 30.7 (range, 20-39) preoperatively to 72.7 (range, 65-77) postoperatively at the time of last follow-up. Arthrodesis was achieved at a mean of 3 months, and there were no complications.

CONCLUSION

The technique described has several advantages when compared to other methods of salvage ankle arthrodesis. The subtalar joint is not included in the fusion unless it is degenerative and symptomatic. Height of the ankle is maintained throughout the fusion process. Furthermore, Trabecular Metal is abundantly available; it avoids donor site morbidity and eliminates the risk of transmissible diseases.

The physicochemical/biological properties of porous tantalum and the potential surface modification techniques to improve its clinical application in dental implantology

More rapid restoration and more rigid functionality have been pursued for decades in the field of dental implantology. Under such motivation, porous tantalum has been recently introduced to design a novel type of dental implant. Porous tantalum bears interconnected porous structure with pore size ranging from 300 to 600μm and a porosity of 75-85%. Its elastic modulus (1.3-10GPa) more closely approximates that of natural cortical (12-18GPa) and cancellous bone (0.1-0.5GPa) in comparison with the most commonly used dental materials, such as titanium and titanium alloy (106-115GPa). Porous tantalum is highly corrosion-resistant and biocompatible. It can significantly enhance the proliferation and differentiation of primary osteoblasts derived from elderly people than titanium. Porous tantalum can allow bone ingrowth and establish not only osseointegration but also osseoincorporation, which will significantly enhance the secondary stability of implants in bone tissue. In this review, we summarize the physicochemical, mechanical and biological properties of porous tantalum. We further discuss the performance of current tantalum dental implants and present the methodologies of surface modifications in order to improve their biological performance.

Ankle fusion with a trabecular metal spacer and an anterior fusion plate

We present a novel operative technique for ankle joint fusion in a case of severe talar bone loss. Fusion was achieved with a trabecular metal spacer combined with a single anterior, anatomically preshaped, angular, stable plate. Excellent postoperative results with good bone consolidation and preservation of lower leg length were present shown at 1 year of follow-up.

Surgical tip: Titanium foam blocks can simplify fusion of failed total ankle replacements

Ankle arthrodesis following failed ankle replacements is a technically challenging task because of the large defect left behind after the prosthesis is removed. The usual practice is to use bulk grafts which are either autografts or allografts to fill the defect. We report our experience with the use of a titanium foam block specifically designed for fusion of failed ankle replacements. This particular method was chosen to avoid the technical difficulties and morbidities associated with the use of bulk autografts and allografts. We describe the surgical technique and early results in the first two cases performed in our unit. The satisfactory clinical and radiologic results in the two cases demonstrate the ability of the titanium foam block to simplify an otherwise complex procedure without compromising the outcome.

Arthrodesis After Failed Total Ankle Replacement

BACKGROUND

The literature on salvage procedures for failed total ankle replacement (TAR) is sparse. We report a series of 17 patients who had a failed TAR converted to a tibiotalar or a tibiotalocalcaneal arthrodesis.

METHODS

Between 2003 and 2012, a total of 17 patients with a failed TAR underwent an arthrodesis. All patients were followed on a regular basis through chart review, clinical examination and radiological evaluation. The following variables were analyzed: pre- and postoperative Meary angle, cause of failure, method of fixation, type of graft, time to union, complications, and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) score. The average follow-up was 30.1 months. The average period from the original arthroplasty to the arthrodesis was 49.8 months.

RESULTS

Thirteen of the 17 ankles were considered radiographically healed after the first attempt in an average time of 3.7 months and 3 after repeat arthrodesis. Bone grafts were used in 16 patients. The median postoperative AOFAS score was 74.5. The mean Meary angle of the hindfoot was 5 degrees of valgus.

CONCLUSION

Tibiotalar and tibiotalocalcaneal arthrodeses were effective salvage procedures for failed TAR. Massive cancellous allografts were a good alternative to compensate for the large bone defect after removal of the prosthesis and to preserve the leg length.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Revision Subtalar Joint Fusion With a Porous Metal Spacer and an Intramedullary Nail: A Case Report

Nonunion of hindfoot arthrodesis can be difficult to successfully treat and will often require bone graft techniques. Large amounts of autogenous bone graft can be difficult to procure and will be associated with donor site morbidity. The use of porous metal implants has been shown to satisfactorily bridge segmental bone defects and to work in conjunction with allogeneic bone graft material, without the risks associated with autogenous bone graft donor site morbidity. The purpose of the present report is to describe the use of a perforated, porous metal implant combined with an intramedullary nail for revision surgery of failed subtalar joint fusion in an adult female patient.

Ankle salvage surgery with autologous circular pillar fibula augmentation and intramedullary hindfoot nail

Tibiotalocalcaneal arthrodesis with an intramedullary hindfoot nail is an established procedure for fusion of the ankle and subtalar joints. In cases involving ankle bone loss, such as in failed total ankle replacement, it can be difficult to salvage with sufficient bone restoration stability and a physiologic leg length and avoiding below the knee amputation. In addition to the alternatives of using a structural allograft or metal bone substitution, we describe the use of autologous ipsilateral circular pillar fibula augmentation in tibiotalocalcaneal retrograde nail arthrodesis combined with a ventral (anterior) plate in a prospective series of 6 consecutive cases with a mean follow-up duration of 26 ± 9.95 (range 12 to 34) months. The 6 patients (3 female and 3 male), with a mean age of 55 ± 13.89 (range 38 to 73) years were treated with revision surgery of the ankle (1 after talectomy, 5 [83.33%] after failed ankle replacement). The visual analog scale for pain and the American Orthopaedic Foot and Ankle Society hindfoot score were used to assess functional outcome, and radiographs and computed tomography scans were used to determine the presence of fusion. All patients improved clinically from pre- to postoperatively in regard to the mean pain visual analog scale score (from 7.5 to 2.0) and American Orthopaedic Foot and Ankle Society hindfoot score (from 29 to 65 points, of an 86-point maximum for fused joints). Radiologically, no loss in the reduction or misalignment of the hindfoot was detected, and all cases fused solid. One patient (16.67%) required hardware removal. The fixation construct provided good clinical and radiologic outcomes, and we recommend it as an alternative to structural allografts or metallic bone grafts for revision ankle surgery with severe bone loss.

Commercially available trabecular metal ankle interpositional spacer for tibiotalocalcaneal arthrodesis secondary to severe bone loss of the ankle

Retrograde tibiotalocalcaneal nailing arthrodesis has proved to be a viable salvage procedure; however, extended bone loss around the ankle has been associated with high rates of nonunion and considerable shortening of the hindfoot. We present the surgical technique and the first 2 cases in which a trabecular metal™ interpositional spacer, specifically designed for tibiotalocalcaneal nailing arthrodesis, was used. The spacer can be implanted using either an anterior or a lateral approach. An integrated hole in the spacer allows a retrograde nail to be inserted, which provides excellent primary stability of the construct. Trabecular metal™ is a well-established and well-described material used to supplement deficient bone stock in surgery of the spine, hip, and knee. It has shown excellent incorporation and reduces the need for auto- and allografts. The trabecular metal™ interpositional ankle spacer is the first trabecular metal spacer designed specifically for ankle surgery. Its shape and variable size will make it a valuable tool for reconstructing bone loss in tibiotalocalcaneal nailing arthrodesis.

Failure of the Agility total ankle replacement system and the salvage options

The Agility total ankle replacement system was the most commonly performed implant in the United States for more than 20 years and has undergone four generations and seven phases of improvement. Much attention has been placed on intraoperative complications, such as malleolar fracture; nerve or tendon injury; and incision healing-related problems, such as wound coverage and infection. However, it is the intermediate- and long-term complications (ie, aseptic osteolysis, subsidence, component loosening, and progressive malalignment) that require careful consideration, because the revision options remain limited. This article reviews the history of the Agility total ankle replacement system in detail, to understand the revision possibilities available.

Fusion following failed total ankle replacement

Although mid- to long-term results after total ankle replacement have improved because of available second- and third-generation devices, failure of total ankle replacement is still more common compared with total hip replacement and total knee replacement. The portfolio of available total ankle replacement revision component options is small. Furthermore, the bone stock of the tibiotalar region is scarce making it difficult and in some situations impossible to perform revision total ankle replacement. In these cases tibiotalar and tibiotalocalcaneal fusions are valuable options. This article describes which surgical procedures should be performed depending on the initial situation and gives detailed advice on surgical technique, postoperative care, and clinical results.

Revision total ankle replacement

This review of the current literature regarding total ankle replacement (TAR) revision surgery focuses on the causes for implant failure, how to deal with the clinical dilemmas of pain and stiffness following TAR, the management of asymptomatic peri-implant cyst formation, and the management of the distal tibia and talus during revision surgery.

Circular external fixator-assisted ankle arthrodesis following failed total ankle arthroplasty

BACKGROUND

Failed total ankle arthroplasty (TAA) often results in significant bone loss and requires salvage arthrodesis. This study quantified the bone loss following failed TAA and reports the outcome of seven arthrodesis reconstructions using the Ilizarov method.

METHODS

A retrospective review of ankle fusions was performed for failed TAA to collect the mode of implant failure, presenting limb length discrepancy (LLD), total bone defect, postarthrodesis LLD, and treatment type (shoe lift versus distraction osteogenesis) and amount (shoe lift or lengthening).

RESULTS

Four mechanical failures and three infections were found. Four of seven cases had prior revision TAAs. Four of seven patients were treated with tibiotalar arthrodesis; three of the seven patients required talar resection and tibiocalcaneal arthrodesis. The mean presenting LLD was 2.2 (range, 1.2 to 3.5) cm. The mean time in frame was 197 (range, 146 to 229) days. With a mean postexplantation total bone defect of 5.1 (range, 3.7 to 8.5) cm, four of seven patients elected tibial lengthening following fusion [mean lengthening 4.6 (range, 2.5 to 8.0) cm; external fixation index (EFI) 42.6 (range, 16.5 to 55.6) days/cm)]. Three of seven patients were treated with a shoe lift [mean lift height 2.9 (range 2.5 to 3.2) cm]. There was no failure of fixation, refracture, or infection. All patients had a stable plantigrade foot and walked with minimal limp. Association for the Study and Application of the Method of Ilizarov (ASAMI) functional scores were six good and one fair. ASAMI bone scores were four excellent and three good.

CONCLUSIONS

Ankle arthrodesis following failed TAA results in large LLDs secondary to bone loss during implant failure and subsequent explantation. External fixation can produce an excellent fusion rate in complex, possibly infected, failed TAAs. Limb length equalization (by either distraction osteogenesis or shoe lift) provides a means of obtaining good functional outcomes following failed TAA.

Ankle arthrodesis: a literature review

Ankle joint arthrodesis should be considered the gold standard procedure for end-stage ankle arthritis in the appropriate patient. Incisional approach and fixation technique should be based on the patient and specific needs. Arthrodesis can be achieved with adequate resection of cartilage, good compression across the fusion site, stable fixation, proper postoperative protocol, and patient compliance. It is important to remember that positioning of the ankle joint is a keystone in ankle arthrodesis. There are complications that can arise from the ankle fusion, including the need for further surgical intervention owing to arthritis in the subtalar and midtarsal joints.

Operative technique of two parallel compression screws and autologous bone graft for ankle arthrodesis after failed total ankle replacement

BACKGROUND

The management of failed total ankle replacement (TAR) depends on the primary indication, presence of infection, condition of adjacent joints, and available bone stock. In addition, the patient's expectations, age, and general health should also be taken into account.

METHODS

This article describes a technique of arthrodesis in failed TAR with two parallel screws inserted in opposite directions and autologous cancellous bone graft. Four patients were managed using this technique. The subtalar joint and both malleoli were preserved.

RESULTS

The average time for radiological union was 14.8 weeks. There were no hardware-related complications or infections. One patient developed subsequent subtalar arthritis and is waiting for subtalar joint fusion.

CONCLUSION

The results from this small series of patients suggest that arthrodesis following failed total ankle replacement with two parallel screws and bone graft may be an effective technique.

Porous tantalum as a structural graft in foot and ankle surgery

BACKGROUND

Structural bone grafts are often used in foot and ankle surgery to fill gaps, maintain height, length or correction. Bone graft, whether autograft or allograft, has limitations and disadvantages. With porosity and mechanical properties similar to native bone, porous tantalum has been used successfully in hip and knee applications. This study investigates the potential advantages of porous tantalum as a substitute for conventional bone graft in foot and ankle surgery.

METHODS

A retrospective review of 27 arthrodesis procedures was performed of foot and ankle procedures using Trabecular Metal porous tantalum over a period of 5 years. Twenty-five patients were involved. Mean age at the time of surgery was 63 (range, 41 to 80) years. All the patients had pathologies in the foot and ankle that required arthrodesis with structural graft. Average followup was 27 (range, 12 to 72) months.

RESULTS

At final followup the mean American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot/Midfoot score improved from 40.6 (range, 16 to 64) preoperatively to 86.3 (range, 57 to 100) postoperatively (p < 0.001). When the pain component of the AOFAS was examined, the score improved from a mean of 8.2 (range, 0 to 20) to 35.2 (range, 20 to 40), (p < 0.001). At the time of last followup, 56% of patients reported no pain, 40% reported mild occasional pain, and 4% reported moderate pain.

CONCLUSION

Porous tantalum therefore, was found to be a viable alternative to conventional bone graft when structural support was required.

10-year survival of total ankle arthroplasties: a report on 780 cases from the Swedish Ankle Register

BACKGROUND AND PURPOSE

There is an ongoing need to review large series of total ankle replacements (TARs) for monitoring of changes in practice and their outcome. 4 national registries, including the Swedish Ankle Register, have previously reported their 5-year results. We now present an extended series with a longer follow-up, and with a 10-year survival analysis.

PATIENTS AND METHODS

Records of uncemented 3-component TARs were retrospectively reviewed, determining risk factors such as age, sex, and diagnosis. Prosthetic survival rates were calculated with exchange or removal of components as endpoint-excluding incidental exchange of the polyethylene meniscus.

RESULTS

Of the 780 prostheses implanted since 1993, 168 (22%) had been revised by June 15, 2010. The overall survival rate fell from 0.81 (95% CI: 0.79-0.83) at 5 years to 0.69 (95% CI: 0.67-0.71) at 10 years. The survival rate was higher, although not statistically significantly so, during the latter part of the period investigated. Excluding the STAR prosthesis, the survival rate for all the remaining designs was 0.78 at 10 years. Women below the age of 60 with osteoarthritis were at a higher risk of revision, but age did not influence the outcome in men or women with rheumatoid arthritis. Revisions due to technical mistakes at the index surgery and instability were undertaken earlier than revisions for other reasons.

INTERPRETATION

The results have slowly improved during the 18-year period investigated. However, we do not believe that the survival rates of ankle replacements in the near future will approach those of hip and knee replacements-even though improved instrumentation and design of the prostheses, together with better patient selection, will presumably give better results.

Stem cell-biomaterial interactions for regenerative medicine

The synergism of stem cell biology and biomaterial technology promises to have a profound impact on stem-cell-based clinical applications for tissue regeneration. Biomaterials development is rapidly advancing to display properties that, in a precise and physiological fashion, could drive stem-cell fate both in vitro and in vivo. Thus, the design of novel materials is trying to recapitulate the molecular events involved in the production, clearance and interaction of molecules within tissue in pathologic conditions and regeneration of tissue/organs. In this review we will report on the challenges behind translating stem cell biology and biomaterial innovations into novel clinical therapeutic applications for tissue and organ replacements (graphical abstract).