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

3D-printed porous tantalum artificial bone scaffolds: fabrication, properties, and applications

Porous tantalum scaffolds offer a high degree of biocompatibility and have a low friction coefficient. In addition, their biomimetic porous structure and mechanical properties, which closely resemble human bone tissue, make them a popular area of research in the field of bone defect repair. With the rapid advancement of additive manufacturing, 3D-printed porous tantalum scaffolds have increasingly emerged in recent years, offering exceptional design flexibility, as well as facilitating the fabrication of intricate geometries and complex pore structures that similar to human anatomy. This review provides a comprehensive description of the techniques, procedures, and specific parameters involved in the 3D printing of porous tantalum scaffolds. Concurrently, the review provides a summary of the mechanical properties, osteogenesis and antibacterial properties of porous tantalum scaffolds. The use of surface modification techniques and the drug carriers can enhance the characteristics of porous tantalum scaffolds. Accordingly, the review discusses the application of these porous tantalum materials in clinical settings. Multiple studies have demonstrated that 3D-printed porous tantalum scaffolds exhibit exceptional corrosion resistance, biocompatibility, and osteogenic properties. As a result, they are considered highly suitable biomaterials for repairing bone defects. Despite the rapid development of 3D-printed porous tantalum scaffolds, they still encounter challenges and issues when used as bone defect implants in clinical applications. Ultimately, a concise overview of the primary challenges faced by 3D-printed porous tantalum scaffolds is offered, and corresponding insights to promote further exploration and advancement in this domain are presented.

Ten-Year Follow-Up of a Customized Total Talar Prosthesis for Revision Total Ankle Arthroplasty: A Case Report

CASE

A 74-year-old woman with rheumatoid arthritis had undergone total ankle arthroplasty (TAA) for severe ankle joint destruction at our hospital 14 years earlier. Radiographs of the ankle revealed displacement of the tibial component and subsidence of the talar component. Revision TAA was performed using a customized alumina ceramic total talar prosthesis.

CONCLUSION

The 10-year outcome of revision TAA with a total talar prosthesis was satisfactory, with no postoperative complications, such as displacement of the tibial component, dislocation of alumina ceramic artificial talus, or progression of degenerative changes in the talonavicular and subtalar joints.

Tibiotalocalcaneal Arthrodesis in Severe Hindfoot Deformities

Tibiotalocalcaneal arthrodesis (TTCA) is the most common and reliable procedure in the treatment of patients with end-stage ankle arthritis combined with severe deformity. Many of these patients present with difficult previous sequelae that include nonunion, malunion, broken implants, vascular deficiencies, skin problems, or a combination of the previous. In that complex scenario, sometimes the only alternative treatment is a below-the-knee amputation. Image studies--weightbearing X-rays, tomography, and magnetic resonance - are fundamental to evaluate alignment and bone stock. When all conservative treatments fail to alleviate pain and dysfunction, the combination of osteotomies and arthrodesis is the procedure of choice. Surgical planning needs to be very detailed and thorough with a special focus on bone loss after debridement of non-healthy tissue and removal of metalwork. TTCA with grafting allows for the preservation of the limb in more than 80% of cases but at the expense of many complications with nonunion rates of approximately 20% of cases. There is controversy about the use of a retrograde nail versus specific TTCA plate and screws but results from biomechanical studies do not show a clear superiority of one specific construct. Amputation rates are close to 5% of cases after repeated failed surgeries. Bulk allografts increase the rate of nonunions but apparently do not have an influence on postoperative infections. Valgus positioning of the ankle/hindfoot is paramount to allow for maximal sagittal plane compensation from the midtarsal joints. Most patients are satisfied with the results of these salvage operations. The studies presented in this article have a considerable wide array of different scenarios that obviously bias some of the results, complications, and outcomes but together they present a persuasive pattern toward considering TTC with grafting and nail or plate fixation as a good salvage procedure that may help the patients to maintain their foot and ankle with a better alignment, function, and pain relief.

Two-Staged Revision Total Ankle Arthroplasty Surgery with Primary Total Ankle Arthroplasty System: A Case Report

CASE

Case of a 2-staged revision surgical technique for the treatment of an aseptic total ankle arthroplasty (TAA) loosening: first surgery: removal of the loosened and painful TAA Scandinavian Total Ankle Replacement, with exclusion of infection, and reconstruction of the large bone defect (bone-defect downsizing surgery); proof of successful ankle bone reconstruction by CT-scan imaging; second surgery: implantation of a primary VANTAGE TAA (ankle reconstruction with new primary TAA).

CONCLUSION

The present case shows the management of a failed TAA with bone defect by performing a 2-step surgical approach: removal of loosened TAA with simultaneous bone stock restoration and then implantation of a new primary TAA. This concept is a possible alternative to a post-TAA ankle arthrodesis or to the use of a TAA revision system.

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.

Midterm Results of Radiographic and Functional Outcomes After Tibiotalocalcaneal Arthrodesis With Bulk Femoral Head Allograft

Background: Tibiotalocalcaneal (TTC) arthrodesis implementing adjunctive allografts is a method of limb salvage for patients with complex hindfoot osseous deficits, though outcome results are limited. The purposes of this study were to assess functional and radiographic outcomes after TTC arthrodesis with femoral head allograft and retrospectively identify prognostic factors. Methods: The authors reviewed 24 TTC arthrodesis procedures with bulk femoral head allografts performed by a single surgeon from 2004 to 2016. Radiographic union at the ankle and subtalar joints along with stability of the allograft were assessed. Patients who had clinically successful arthrodeses were contacted to score the Foot and Ankle Ability Measure-Activities of Daily Living (FAAM-ADL) questionnaire, Visual Analog Scale (VAS) for pain, and Short Form-12 (SF-12) at a mean of 58.0 months (range, 28-102) postoperatively. Results: Complete radiographic union of involved joints was achieved in 15 patients (63%) and in 75% (36/48) of all joints; 21 ankles (88%) were assessed to be radiographically stable at final follow-up. Three patients (13%) underwent revision arthrodesis at a mean of 18.9 months postoperatively, and 21 patients (88%) did not require additional surgery as of final follow-up. Patients significantly improved to a mean FAAM-ADL score of 71.5 from 36.3 (P < .001). The mean VAS for pain significantly improved from 77.2 to 32.9 (P < .001). Male sex (P = .08) and a lateral operative approach (P = .03) both resulted in worse outcomes. Conclusion: Use of a femoral head allograft with TTC arthrodesis can offer improved functional scores and sustained radiographic outcomes.Level of Evidence: Level IV: Case series.

Porous Tantalum and Titanium in Orthopedics: A Review

Porous metal is metal with special porous structures, which can offer high biocompatibility and low Young's modulus to satisfy the need for orthopedic applications. Titanium and tantalum are the most widely used porous metals in orthopedics due to their excellent biomechanical properties and biocompatibility. Porous titanium and tantalum have been studied and applied for a long history until now. Here in this review, various manufacturing methods of titanium and tantalum porous metals are introduced. Application of these porous metals in different parts of the body are summarized, and strengths and weaknesses of these porous metal implants in clinical practice are discussed frankly for future improvement from the viewpoint of orthopedic surgeons. Then according to the requirements from clinics, progress in research for clinical use is illustrated in four aspects. Various creative designs of microporous and functionally gradient structure, surface modification, and functional compound systems of porous metal are exhibited as reference for future research. Finally, the directions of orthopedic porous metal development were proposed from the clinical view based on the rapid progress of additive manufacturing. Controllable design of both macroscopic anatomical bionic shape and microscopic functional bionic gradient porous metal, which could meet the rigorous mechanical demand of bone reconstruction, should be developed as the focus. The modification of a porous metal surface and construction of a functional porous metal compound system, empowering stronger cell proliferation and antimicrobial and antineoplastic property to the porous metal implant, also should be taken into consideration.

The Use of Tantalum Metal in Foot and Ankle Surgery

There are several reconstructive procedures in foot and ankle surgery wherein structural grafts are needed to fill defects, restore height, and maintain correction while providing an osteoconductive environment until fusion occurs. Traditionally used autografts and allografts have their disadvantages and limitations. Porous tantalum, with stiffness similar to bone and its biocompatibility, can be a viable option in foot and ankle reconstructive procedures.

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).

Custom-made total ankle arthroplasty for the salvage of major talar bone loss

Aims

A failed total ankle arthroplasty (TAA) is often associated with much bone loss. As an alternative to arthrodesis, the surgeon may consider a custom-made talar component to compensate for the bone loss. Our aim in this study was to assess the functional and radiological outcome after the use of such a component at mid- to long-term follow-up.

Patients and Methods

A total of 12 patients (five women and seven men, mean age 53 years; 36 to77) with a failed TAA and a large talar defect underwent a revision procedure using a custom-made talar component. The design of the custom-made components was based on CT scans and standard radiographs, when compared with the contralateral ankle. After the anterior talocalcaneal joint was fused, the talar component was introduced and fixed to the body of the calcaneum.

Results

At a mean follow-up of 6.9 years (1 to 13), 11 ankles were stable with no radiological evidence of loosening. Only one was lost to follow-up. The mean arc of movement was 21° (10° to 35°). A total of nine patients (75%) were satisfied or very satisfied with the outcome, two (17%) were satisfied but with reservations and one (8%) was not satisfied. All but one patient had an improvement in the American Orthopaedic Foot and Ankle Society hindfoot score (p = 0.01). Just one patient developed deep infection, leading to arthrodesis.

Conclusion

A custom-made talar component yielded satisfactory results with regard to function, stability and satisfaction. This should encourage the use of such components as an alternative to arthrodesis of the ankle in patients with a failed TAA. Cite this article: Bone Joint J 2017;99-B:231–6.

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.

Total ankle replacement

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Incidence of Complications During Initial Experience with Revision of the Agility and Agility LP Total Ankle Replacement Systems: A Single Surgeon's Learning Curve Experience

As the frequency in which foot and ankle surgeons are performing primary total ankle replacement (TAR) continues to build, revision TAR will likely become more commonplace, creating a need for an established benchmark by which to evaluate the safety of revision TAR as determined by the incidence of complications. Currently, no published data exist on the incidence of intraoperative and early postoperative complications during revision of the Agility or Agility LP Total Ankle Replacement Systems during the surgeon learning curve period; therefore, the authors sought to determine this incidence during the senior author's learning curve period.

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.

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.

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.

Strategies for Revision Total Ankle Replacement

As the frequency of primary total ankle replacement (TAR) continues to build, revision will become more commonplace. At present there are no “standard principles” associated with revision TAR. What is clear is that the current approaches are technically complex, fraught with complications and no one approach represents the only answer. Exchange of TAR metallic components to the same system standard or dedicated revision components are viable options with limited occurrence of complications. Explantation and conversion to custom-design long stemmed components has limited availability. Explantation and conversion to another TAR system is high-risk and has strong potential for complications. The use of metal reinforced polymethylmethacrylate cement augmentation of failed TAR systems and tibio-talo-calcaneal arthrodesis should be reserved for very select situations where other options are not possible. There is a real need for long-term survivorship following revision TAR and future efforts ought to be directed in this area.