Tibiotalocalcaneal Arthrodesis for Severe Talar Avascular Necrosis

Midfoot Tarsectomy in Cavovarus: Why PSI Makes a Difference?

The cavovarus foot is a complex deformity that can be treated using multiple surgical procedures, ranging from soft tissue surgery to triple arthrodesis. Among these options, anterior midfoot tarsectomy is a three-dimensional closed-wedge osteotomy, traditionally performed slowly and progressively in a blind fashion, and remaining a challenge for unexperimented surgeons with variable outcomes. As such, we investigated and discussed the use of patient-specific cutting guides (PSCGs) in computer-assisted anterior midfoot tarsectomy in terms of accuracy, reproducibility, and safety.

The use of a 3D printed titanium implant for arthrodesis in the management of large osseous defects in the ankle

BACKGROUND

Large osseous defects (LOD) in the ankle occur because of multiple aetiologies. Advancement in 3-dimensional (3D) printing technologies has led to the use of custom implants and instrumentation their management. A 3D printed patient-specific porous titanium cage which allows for peripheral osteo-integration and autogenous bone-grafting could be an ideal implant in these cases.

METHODS

Retrospective review of a multi-centre, multi-surgeon consecutive cohort of patients requiring either TTC or AA for a large osseous defect between June 2019 - August 2020. A custom titanium prosthesis was 3D-printed according to CT measurements for implantation.

RESULTS

Mean follow up was 19.5 months (range 12-24 months). Plain radiographs and CT scans at 12 months confirmed osseointegration (stability) in 11of 13 patients (84%). Two patients developed late infection, one requiring revision surgery.

CONCLUSIONS

3D-Printed titanium implants in the management of LODs in the ankle offer a comparable success rate to other reported procedures, with unlimited geometric possibilities in the design allowing for accurate length correction. Their structural stability may offer an advantage over conventional bone graft techniques and limits the amount of bone-graft required.

LEVELS OF EVIDENCE

LOE III.

Revision of Subtalar Joint Arthrodesis: Considerations for Bone Grafting, Fixation Constructs, and Three-Dimensional Printing

Subtalar joint arthrodesis is a commonly used procedure for numerous pathologic conditions in the foot and ankle. Although rarely performed in isolation, this procedure can provide successful resolution of various lower-extremity complaints. There are traditional approaches to isolated subtalar joint arthrodesis; however, when these fail, the authors recommend alternatives to enhance the success of revisional surgery. These include the use of intramedullary nailing, larger harvest of autograft, and metallic wedge.

Tibiotalar and Tibiotalocalcaneal Arthrodesis with Paragon28 SilverbackTM Plating System in Patients with Severe Ankle and Hindfoot Deformity

BACKGROUND AND OBJECTIVES

The treatment of end-stage ankle osteoarthritis (OA) and associated hindfoot deformities remains a major challenge for orthopedic surgeons. Numerous techniques and surgical approaches have been proposed for tibiotalar (TT) and tibiotalocalcaneal (TTC) arthrodesis, from arthroscopic to open, as well as numerous devices proposed for internal fixation (retrograde intramedullary nails, cannulated screws, and plating systems). The aim of this study was to retrospectively analyze the results, with at least 18 months of follow-up, with Silverback^TM TT/TTC Plating System Paragon28 in a group of 20 patients with severe OA and hindfoot deformities (mainly secondary post-traumatic OA).

MATERIALS AND METHODS

The demographic characteristics and past medical history of the patients were collected and analyzed to identify the cause of the pathology. The degree of OA and deformity were quantified based on foot and ankle weight-bearing radiography and CT examination. Pre- and post-operative clinical and functional scores (ROM, VAS, AOFAS, FFI, and SF-36) and radiographic parameters (anterior distal tibial angle, tibiotalar angle, coronal tibiotalar angle, and hindfoot alignment angle) were evaluated.

RESULTS

All of the patients showed clinical and radiographic fusion at an average of 14 weeks (range 12-48), with improvement in pain and functional scores, without major surgical complications and/or infections.

CONCLUSIONS

Despite the limitations of our study, the results with this new plating system showed good results in terms of bone consolidation, post-operative complications, and improvement of pain and quality of life in patients with severe OA and deformities of the ankle and hindfoot.

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.

Improved Pain and Function After TTC Fusion With a Custom Cage

BACKGROUND

Three-dimensional custom cages can be used to treat complex ankle and hindfoot pathology and bone loss with potentially better patient satisfaction and higher fusion rates than tibiotalocalcaneal (TTC) fusion alone or in combination with bulk femoral head allograft. Yet there is limited literature to support this procedure. The purpose of this study is to objectively quantify the clinical and radiologic outcomes of patients undergoing patient-specific 3D-printed custom cage implantation to fill large defects around the ankle joint region as part of a limb-salvaging TTC fusion.

METHODS

This is a retrospective review of 21 patients (mean age 59.3 years) who underwent custom cage implantation with a TTC retrograde fusion nail by a single surgeon for massive bone loss of the ankle and hindfoot. Patient charts were reviewed for pain and functional outcomes, complications, and various demographics, including number of previous surgeries to the ipsilateral ankle. Mean follow-up was 32 months. All 21 patients had preoperative and postoperative pain and function scores available for analysis.

RESULTS

A total of 20 (95.2%) of the 21 patients had their cage in situ at final follow-up. Overall, with the numbers available, visual analog scale (VAS) for pain, Foot and Ankle Ability Measure (FAAM) activities of daily living subscale, and the 12-Item Short Form Health Survey (SF-12) mental and physical health scores significantly improved from preoperative to final follow-up. However, when compared to the overall US population of age-matched 55- to 64-year-old individuals, patients still remained relatively disabled. There were 2 failures, one of which required amputation and the other was treated nonoperatively with bracing.

CONCLUSION

In conclusion, in this relatively small, single-surgeon series, we found that 3D-printed custom cage technology offered a viable option for complex TTC fusion procedures performed in the presence of significant bone loss, with good fusion rates, however relatively modest improvement in functional outcomes.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Tibiotalocalcaneal Arthrodesis with Structural Allograft for Management of Large Osseous Defects of the Hindfoot and Ankle: A Systematic Review and Meta-Analysis

Large osseous defects of the hindfoot and ankle pose a surgical challenge. Tibiotalocalcaneal (TTC) arthrodesis utilizing a structural allograft may be required to fill the osseous void, preserve limb length and achieve fusion. Several authors have reported small case series on this topic, however outcomes have varied and no systematic review of this data has been published to date. The primary aim of this study is to report rates of osseous union, limb salvage and complications in patients undergoing TTC arthrodesis with a structural allograft. A total of 11 publications were identified that met the inclusion criteria. One hundred seventy-five patients were included with a weighted mean age of 60.5 (range 50-72) years and follow-up period of 29.7 (range 3-62) months. Femoral head allograft was the most commonly utilized structural graft and a retrograde intramedullary nail was the most common fixation construct. Results demonstrated an overall union rate of 67.4%, limb salvage rate of 92.5% and complication rate of 26.6%. Allograft-related complications were rare with an allograft fracture rate of 0.1% and allograft collapse rate of 1.2%. There was no significant difference in union rate when using a retrograde intramedullary nail versus a plate construct (p = .9148). TTC arthrodesis with use of a structural allograft is a viable treatment option for limb salvage when faced with complex hindfoot and ankle pathology involving large osseous defects. Despite high rates of radiographic nonunion, this approach can provide patients with a stable and functional limb while avoiding amputation.

Biologic Augmentation of Tibiotalocalcaneal Arthrodesis With Allogeneic Bone Block Is Associated With High Rates of Fusion

BACKGROUND

The orthopaedic conditions and systemic comorbidities that occur in patients who require bone block tibiotalocalcaneal (TTC) arthrodesis have made this procedure associated with a higher-than-normal risk of nonunion, graft collapse, hardware failure, and amputation. Here, we present a novel approach to bone block TTC arthrodesis using adjunctive osteoinductive agents and a prolonged course of protected weightbearing to assess if we could improve on historical outcomes. We also evaluated the efficacy of a vascularized medial femoral condyle (MFC) free flap to augment TTC arthrodesis.

METHODS

Fourteen adult patients underwent bone block TTC arthrodesis biologically augmented with fresh-frozen femoral head allograft, bone marrow aspirate concentrate, and demineralized bone matrix cortical fibers. Three patients with soft tissue defects underwent vascularized reconstruction with an MFC free flap. Radiographic union, the Foot Function Index (FFI), and PROMIS pain interference (PI), and physical function (PF) scores were assessed at follow-up.

RESULTS

TTC fusion was documented on plain radiograph in 13 of 14 patients (92.9%) and CT in 10 of 11 patients (90.9%). Mean time to fusion was 183.2 ± 83.2 days. One patient (7.1%) experienced nonunion and persistent infection requiring amputation. Patients who underwent vascularized bone grafting had significantly shorter time to fusion (112.3 ± 31.7 days vs 204.4 ± 82.7 days, P = .05). Patient-reported outcomes revealed mild to moderate pain and dysfunction after 1 year (mean FFI = 41.0% ± 23.1%, PROMIS PI = 58.3 ± 1.8, PROMIS PF = 39.0 ± 2.2).

CONCLUSION

In this relatively small series, the biologic augmentation of bone block TTC arthrodesis with osteoinductive agents and protective weightbearing resulted in excellent rates of fusion, modest pain, and preserved function of the lower extremity in almost all those treated. Osseous healing appears to be enhanced and accelerated with application of an MFC flap. We believe that this approach offers a viable salvage option for these challenging clinical problems.

LEVEL OF EVIDENCE

Level IV, case series.

Treatment of Severe Avascular Necrosis of the Talus Using a Novel Keystone-Shaped 3D-Printed Titanium Truss Implant

Background

Avascular necrosis (AVN) of the talus most commonly occurs secondary to trauma. Significant bone loss and collapse in severe talar AVN remains an operative challenge. Tibiotalocalcaneal arthrodesis (TTC) using femoral head allograft is at risk of collapse and subsidence. The use of a void-filling titanium truss can mitigate against this. This study describes the use of a novel keystone shaped 3D-printed titanium truss for treatment of severe talar AVN.

Methods

Three patients with end-stage AVN of the talus were included. Each patient underwent a TTC arthrodesis with a custom-made, 3D-printed, keystone-shaped, truss implant in conjunction with a hindfoot intramedullary nail. Modified patient American Orthopaedic Foot & Ankle Society (AOFAS) scores were recorded at the preoperative, 6-month, 12-month, and annual postoperative timepoints.

Results

All patients progressed to satisfactory radiological union by one year. Mean follow up time was 32 months (24-48 months). Mean preoperative modified AOFAS score was 5. There was progressive improvement in AOFAS scores from 6 months postoperatively. Mean modified AOFAS score improved from 28 at 6 months to 37 at 2 years postoperatively.

Conclusion

Custom-made 3D-printed titanium trusses provide promising outcomes for treating severe AVN of the talus. The "keystone" design is advantageous as it allows for bone stock preservation and conforms to the shape of the native calcaneum. All patients showed progressive improvements in outcomes at sequential time intervals postoperatively. The implant provides a strong mechanical structure resisting collapse and subsidence during the arthrodesis process.

Level of Evidence

Level IV, retrospective case series.

Avascular Osteonecrosis of the Talus: Current Treatment Strategies

Avascular osteonecrosis (AVN) of the talus (AVNT) is a painful and challenging clinical diagnosis. AVNT has multiple known risk factors and etiologies and presents at different stages in severity. Given these unique factors, the optimal treatment solution has yet to be determined. Both joint-preserving and joint-sacrificing procedures are available, including core decompression and arthrodeses. Recently, new salvage and replacement techniques have been described including vascularized pedicle bone grafts and total talus replacement using patient-specific prosthesis; however, evidence remains limited. This review examines the current trends AVNT treatment and the emerging data behind these novel techniques.

The King's Sliding Hindfoot Osteotomy for the Treatment of Talus Body Defects-Results of a New Technique in Tibiotalocalcaneal Arthrodesis

Bone loss after avascular necrosis of the talus secondary to acute traumatic or chronic pathologies often requires surgical reconstruction. This study reports the early results of a sliding oblique hindfoot osteotomy for salvage procedures combined with tibiotalar arthrodesis to achieve a well-aligned, painless, plantigrade foot. All patients presenting to our institution with severe talus body defects requiring corrective surgery between January 2016 and August 2020 were included. An oblique osteotomy of the diseased talus was performed to correct anterior talus subluxation and prevent excessive loss of height at the tibiotalar apposition and to correct varus-valgus deformity. A retrograde hindfoot nail was used for intramedullary tibiotalocalcaneal arthrodesis. Patients were prospectively followed. Primary outcomes included assessment of mobility and union at 6 months. Secondary outcomes included 30-day postoperative complications, patient satisfaction and change in American Orthopaedic Foot & Ankle Society (AOFAS) score at 1-year postoperation. Nine patients underwent this procedure with a mean follow-up of 18 months (4-36 months). Average age was 66 (58-81) years. Mean body mass index was 33.7 (22-38) kg/m². All patients went on to fusion and were ambulating at 6 months (n = 8). At 1 year, the mean improvement in AOFAS was 28.9 points (p < .05) (n = 7) and all patients were satisfied with the outcome of their treatment. This technique represents an alternative to conventional hindfoot salvage techniques showing predictable outcomes in complex hindfoot deformity with talar body collapse and anterior subluxation. Further quantitative studies are needed to define if this technique minimizes limb shortening/limb-length discrepancies when compared to traditional horizontal cuts.

Outcome of Pantalar Fusion With Femoral Head Allograft in Avascular Necrosis of Talus

Background: Avascular necrosis (AVN) of the talus is a challenging condition that is caused primarily by trauma. The severity of the talus fracture determines the risk of AVN. Severe osteonecrosis with the loss of talar integrity can be treated with arthrodesis and structural bone graft.

Method: This study shows the experience of pantalar arthrodesis using hindfoot arthrodesis nail, screw fixation, and femoral head allograft in four patients.

Result: All patients were satisfied in terms of pain and function after an average of 4 months postsurgery. Limb length discrepancy was <1 cm and hindfoot fusion was achieved by 3 months. The mean score for SF-36 physical function and AOFAS hindfoot score at a 2-year postpantalar arthrodesis was 88 and 80.8, respectively.

Conclusion: Hindfoot ankle arthrodesis, with the usage of femoral head allograft, can be successfully used for the treatment of traumatic AVN of talus.

Total Ankle Total Talus Replacement Using a 3D Printed Talus Component: A Case Report

The 3D custom total talus replacement is a novel treatment for avascular necrosis of the talus. However, patients who require a total talus replacement often have concomitant degenerative changes to the tibiotalar, subtalar, or talonavicular joints. The combined 3D custom total ankle-total talus replacement (TATTR) is used for patients with an unreconstructable talus and adjacent tibial plafond involvement. The goal of performing a TATTR is to provide pain relief, retain motion at the tibiotalar joint, maintain or improve the patient's functional status, and minimize limb shortening. TATTR is made possible by 3D printing. The advent of 3D printing has allowed for the accurate recreation of the native talar anatomy with a talar dome that can be matched to a total ankle replacement polyethylene bearing. In this article, we will discuss a case of talar avascular necrosis treated with a combined TATTR and review the current literature for TATTR.

Three-dimension correction of Charcot ankle deformity with a titanium implant

BACKGROUND

Charcot neuroarthropathy of the ankle is an extremely challenging clinical dilemma, and its surgical management can be highly complicated. The goal of Charcot ankle treatment is to to restore a plantigrade and stable foot, and thus to avoid ulceration with subsequent infection. This report aims to introduce a method of correcting ankle deformity using a novel 3D printing technique.

PATIENT AND METHODS

One patient with Charcot ankle deformity was operated in this study. The ankle deformity of this patient was quantified in three dimensions through computed tomography. On the basis of the computed tomography scans, a new titanium implant was designed and manufactured using 3D printing. The implant was applied in the surgery of tibio-talo-calcaneal arthrodesis to restore local anatomy of the affected ankle of the patient with Charcot neuroarthropathy.

RESULTS

Evaluation of the post-operative radiography indicated union in the affected ankle. After surgery, the planar foot in this patient was restored. The patient was satisfied with the post-operative course, and joint fusion was successful as indicated by 2-year post-operative evaluation. The results of post-operative follow-up showed that the lower limb length of the patient with Charcot neuroarthropathy was salvaged, and the patient retained the plantigrade foot.

CONCLUSION

Three-dimensional printing technique combined with tibio-talo-calcaneal arthrodesis may help to correct ankle deformity in patients with Charcot neuroarthropathy.

Revision of the Malaligned Ankle Arthrodesis

A malaligned ankle arthrodesis is a painful and complicated pathology. Deformities may be present in the frontal, sagittal, or transverse plane or a combination of planes. Thorough preoperative evaluation of the deformity and the patient as a whole is crucial to successful revision. Surgical site for revision should be based on center of rotation of angulation, when possible. Revision commonly is performed through opening wedge osteotomy. Closing wedge and focal dome osteotomies, however, are excellent options. Revision also may be performed through external fixation or total ankle replacement. Although the literature is not rich with data, the options discussed provide favorable results.

Medial Femoral Condyle Free Flap Reconstruction of Complex Foot and Ankle Pathology

Background:

Complex hindfoot pathology may benefit from vascularized bone flap reconstruction rather than traditional bone grafting techniques. Medial femoral condyle (MFC) flaps provide vascularized periosteum, skin, and corticocancellous bone.

Methods:

A retrospective, single-institution cohort study of consecutive MFC flaps performed for complicated hindfoot reconstruction between 2013 and 2019 was reviewed. Radiologic follow-up assessed osseous union and clinical outcomes were evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score. Thirty MFC flaps were performed in 28 patients for complex hindfoot pathology. Twenty-seven flaps had adequate clinical and radiographic follow-up (mean 15.8 months).

Results:

The majority presented with avascular necrosis (83%) and failed prior operations (67%, mean 3.1). Most hindfoot procedures involved arthrodesis (n = 24, 80%); tibiotalocalcaneal (n = 11) and talonavicular (n = 7) most frequently. Mean osseous flap volume was 10.3 cm3 (range 1.7-18.4 cm3); one flap required takeback for venous congestion but no total flap losses occurred. Primary osseous union was initially achieved in 20 patients (74%, mean 217 days). Six flaps developed interface nonunion; 5 underwent revision arthrodesis and ultimately achieved union in 24/27 flaps (89%, mean 271 days). Risk factors for nonunion were body mass index (BMI) >30 ( P = .017) and prior arthrodesis ( P = .042). Mean AOFAS hindfoot scores increased significantly from 52.3 preoperatively to 70.7 postoperatively ( P < .001). Subscore analysis demonstrated significant improvement in postoperative pain scores from 14.2 to 27.3 out of 40 ( P < .001).

Conclusion:

The MFC free flap provided vascularized bone for complicated foot and ankle reconstruction with relatively low donor site morbidity, promising osseous union results, and improved functional outcomes.

Level of Evidence:

Level IV, retrospective case series.