Treatment of Osteonecrosis of the Talus

Outcomes of cobalt-chrome 3D-printed total talus replacement with and without combined total ankle replacement

BACKGROUND

Collapse of the talus and peri-talar arthritis pose treatment challenges due to the anatomy and location of the talus as a keystone of the foot and ankle. Custom 3D-printed total talus replacement (TTR) and combined total ankle total talus replacement (TATTR) have emerged as treatment options for these pathologies. However, the safety and efficacy of these implants is unknown due to the limited number of cases and short follow-up durations.

METHODS

This was a retrospective study to assess surgical outcomes of patients who underwent a TTR and TATTR with or without subtalar fusion. Patient demographics, intraoperative parameters, device related surgical and non-surgical events, imaging and clinical evaluations, and patient reported outcome (PRO) measures were compiled.

RESULTS

A total of 38 patients received a custom 3D-printed implant with mean follow-up time of 22.1 (range: 12-45) months. In this cohort, 7 (18.4 %) required secondary surgery and 3 (7.9 %) required implant removal. Multivariate logistic regression revealed that patient diagnosis of depression was a significant predictor of secondary surgery with an OR 17.50 (p = 0.037). Significant postoperative improvements were observed in the talocalcaneal height (p = 0.005) and talar declination angle (p = 0.013) for the TATTR group. VAS and PROMIS pain interference (PI) scores demonstrated an initial significant improvement in pain, but this improvement did not maintain significance at most recent follow-up. However, there was a significant increase in the PROMIS physical function (PF) scores (p = 0.037) at most recent follow-up.

CONCLUSION

These results demonstrate that TTR and TATTR provide significant improvement in post-operative radiographic foot and ankle alignment and physical function at the two-year timepoint. PRO findings suggest that patients are more active after surgery. Surgeons considering proceeding with either of these procedures should counsel patients about pain and functional outcomes as well as realistic expectations in patients with depression.

LEVEL OF EVIDENCE

Level 3.

Partial talar replacement with a novel 3D printed prosthesis

BACKGROUND

The treatment of talus avascular necrosis (AVN) is challenging owing to its unique anatomical features. Despite decades of studies, till date, there is no appropriate treatment for talus AVN. Therefore, surgeons need to develop newer surgical methods. In the present study we introduce a new surgical method, 3D printed partial talus replacement (PTR), to treat partial talus necrosis and collapse (TNC).

METHODS

A male patient with talus AVN underwent PTR in our hospital. The morphology of the talus was quantified using 3D computed tomography (CT) imaging. A novel 3D printed titanium prothesis was designed and manufactured according to the findings of the CT imaging. The prosthesis was applied during talus replantation surgery to reconstruct the anatomical structure of the ankle. The follow-up period for this patient was 24 months. The visual analog scale (VAS) scores before and after surgery, American Orthopedic Foot and Ankle Score (AOFAS), ankle range of motion, and postoperative complications were recorded to evaluate the prognosis.

RESULTS

The anatomical structure of the talus was reconstructed. The patient was satisfied with the effects of treatment, recovery, and function. The VAS score decreased from 5 to 1. The AOFAS improved from 70 to 93. The range of motion remained the same as that during the pre-operation. The patient returned to a normal life.

CONCLUSION

3D printed PTR is a new surgical method for talus AVN that can provide satisfactory outcomes. In future, PTR might be an effective and preferential treatment for the treatment of partial talus AVN and collapse.

Functional Outcomes and Complications Associated With Total Talus Arthroplasty: A Systematic Review

Total talus arthroplasty (TTA) is a motion sparing procedure which can be utilized in specific and unique cases of talar necrosis and/or collapse. Literature on TTA is limited and predominantly composed of case studies or case reports. The purpose of this publication is to compile a systematic review of functional outcomes and complications associated with TTA. A search of current literature on TTA with >1-year follow-up was performed. Studies that described talar body implants or talonavicular implants were excluded. Twenty articles met inclusion criteria, which represented 161 TTAs. The average follow-up was 37.35 months (9-60 months). The indication for a TTA was predominately avascular necrosis of the talus, comprising 75.78% (122/161) of cases. The overall complication rate was 9.32% (15/161), with wound healing complications (5/161), replacement or implantation of a tibial component (4/161), and medial malleolus fracture (3/161) being the most common. One patient required proximal amputation due to residual pain and deformity. Functionally, American Orthopedic Foot and Ankle Score increased from 27.93 preoperative to 81.99 postoperative and Japanese Society for Surgery of the Foot Score increased from 43.2 preoperative to 89.34 postoperative. Visual analog scale pain score decreased from 6.44 to 2.60. Total ankle range of motion increased from 36.60° to 46.74°. Ankle plantarflexion increased by 3.45° and ankle dorsiflexion increased by 6.69°. Overall, available literature on TTA appears to be in favor of the procedure when indicated.Levels of Evidence: 4.

3D-Printed Total Talus Replacement After Free Vascularized Medial Femoral Condyle Osteocutaneous Flap for Avascular Necrosis of the Talus Leads to Poor Clinical Outcomes: A Case Series

INTRODUCTION

Avascular necrosis (AVN) of the talus is 1 of the most difficult foot and ankle pathologies to diagnose and manage. The purpose of this study was to report on the functional outcomes of 3D-printed total talus replacement (TTR) in 2 patients with talar AVN who both underwent a failed revascularization.

METHODS

This is a case series of 2 patients with TTR after a failed revascularization and a comparison group of 25 patients with primary TTR. Clinical and functional outcomes are used to compare both groups.

RESULTS

Patient 1 had a postrevascularization Visual Analogue Scale (VAS) pain score of 9. Imaging showed failure of the medial femoral condyle to incorporate with talar fragmentation. Patient underwent TTR at 5 months postoperatively. At 2 years postoperatively, the patient underwent a cavovarus foot reconstruction; however, patient continued to suffer from ankle pain (VAS 6) and ultimately underwent below knee amputation at 3 years after the TTR. Patient 2 initially underwent a core decompression for a talar bone infarct followed by revascularization procedure at 6 months postoperatively due to persistent pain and bony infarcts. At 18 months postrevascularization, the patient had a VAS pain score of 9 and progression of the AVN. She underwent a TTR. At 1-year follow-up, the VAS pain score was 8. Both patients had an ankle plantarflexion of 30° at their last TTR follow-up. The comparison group consisted of 25 patients who underwent 3D-printed TTR with mean postoperative VAS score and ankle plantarflexion of 3.7° and 41.8°.

CONCLUSION

Patients 1 and 2 demonstrated reduced plantarflexion and ankle motion after TTR relative to the comparison group which improved in both physical assessments. The first patient needed a below knee amputation for persistent pain. Patient 2 showed less improvement in all the foot and ankle outcome scores as compared with the primary TTR group.

LEVEL OF EVIDENCE

Level V: Retrospective case series.

Early Outcomes of Combined Total Ankle Total Talus Replacement Using a 3D-Printed Talus Component With Hindfoot Arthrodesis

Late-stage talar avascular necrosis (AVN) results in devascularization of the talus with osteonecrosis and subchondral collapse. A combined total ankle and total talus replacement (TATTR) with hindfoot arthrodesis may be utilized for end-stage talar AVN with tibiotalar and hindfoot joint arthritis. The purpose of this study is to evaluate the short-term outcomes of combined TATTR with hindfoot arthrodesis. Patients who underwent a combined TATTR or TTR with a hindfoot arthrodesis (subtalar with or without talonavicular arthrodesis) from 2016 to 2020 were retrospectively reviewed. Patient demographics, comorbidities, and surgical data were collected. Outcomes included the Visual Analog Scale (VAS) scores, range of motion, radiographic parameters, union rates, and complications. A total of 18 patients were reviewed. Nine patients were included with an average of 19.4 months follow-up. Significant postoperative improvements were observed in VAS scores (P < .001), ankle plantarflexion (P = .04), talocalcaneal height (P = .03), and tibiotalar alignment (P = .02). All patients achieved a successful union of their subtalar and talonavicular joints arthrodesis. There was one reoperation for a persistent varus ankle deformity. This is the first study to evaluate the clinical outcomes, radiographic outcomes, and union rate in combined TATTR with hindfoot arthrodesis. The early results demonstrated significant clinical improvement with 100% hindfoot union rate and no prosthetic failure.Level of Evidence: IV.

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.

Incorporating 3D Printing Into Your Practice: Lessons Learned

Three-dimensional (3D) printing has greatly benefited medicine, manufacturing vital organs like skin, hearts, kidneys, and livers. Early studies on 3D printing in surgery have consistently reported decreased operative time and improved precision. This technology has gained popularity with orthopaedic surgeons in knee, hip, and shoulder surgeries because 3D printing is associated with enhancing osseointegration. However, this innovation is still not commonly used among foot and ankle surgeons; one reason is that whereas the literature on 3D printing-assisted surgery is populated with studies on operative techniques and clinical outcomes, there exists an ambiguity on how to incorporate this feature into the clinic. Thus, the aim of this technology column is to consolidate and standardize a workflow to guide foot and ankle surgeons on integrating 3D printing into one's practice. We describe a model developed by a single surgeon at one institution who directs a large caseload of 3D-printed foot and ankle surgeries. From the initial patient visit to the interaction between the surgeon and the implant engineering team, to documentation of data adding to the preliminary literature, this work has great implications on streamlining the assimilation of a highly successful technology to improve foot and ankle surgery for both surgeons and patients.Level of Evidence: Level V.

Anatomical basis of a pedicled cuboid bone graft based on the lateral tarsal artery for talar avascular necrosis

PURPOSE

Vascularized pedicled bone-grafting from the cuboid to the talus provides low donor site morbidity and satisfactory outcomes in patients with early-stage talar avascular necrosis. We investigated the anatomy of the rotational vascularized pedicled bone graft from the cuboid.

METHODS

15 embalmed cadaver specimens were perfused with red latex via the popliteal artery. The lateral malleolus was dissected. The course of the lateral tarsal artery and the vascular territory in the cuboid supplied by the lateral tarsal artery were observed. Vessel diameters were measured.

RESULTS

The course of the lateral tarsal artery to the cuboid was consistent, and a vascularized pedicle of the lateral tarsal artery was present in all specimens. Mean diameter of the lateral tarsal artery was 1.40 ± 0.12 mm (range 1.67-1.25). Mean length of the vascularized pedicle was 67.15 ± 3.18 mm (range 62.43-74.36). The pedicle bone graft was long enough to reach the bony border of both the lateral and medial malleolus.

CONCLUSION

A vascularized pedicled cuboid bone graft based on the lateral tarsal artery has clinical utility for early-stage talar avascular necrosis.

Avascular Necrosis of the Talus

Talar osteonecrosis results from trauma to the fragile blood supply to the talus. Many etiologies exist that can cause talar osteonecrosis, with the most common being talar neck fractures. Patients with talar osteonecrosis frequently present with progressive ankle pain and limited range of motion. Treatment strategy depends primarily on the stage of disease. Conservative care in the form of medications and bracing treatment can be beneficial for patients with low functional status and early disease stages. Surgical options also exist for early disease without talar collapse that can potentially preserve the tibiotalar joint. Once talar collapse develops, surgical treatment is move invasive and typically involves an arthrodesis or talus arthroplasty. Although some treatment guidelines exist based on the disease stage, talar osteonecrosis is a complex problem, and treatment strategy should always be determined on a case-by-case basis carefully examining all clinical aspects.

3D Printed Total Talus Replacement for Avascular Necrosis of the Talus

BACKGROUND

Talus avascular necrosis (AVN) is a challenging entity to treat. Management options depend on disease severity and functional goals. Total talus replacement (TTR) is a treatment option that maintains joint range of motion. The literature on TTR is limited with variability in implant design and material. The purpose of this study was to evaluate outcomes following TTR with a custom 3D printed metal implant.

METHODS

Patients who underwent TTR were retrospectively reviewed over a 3-year period. Basic demographic data and comorbidities were collected. Medical records were reviewed to obtain postoperative and preoperative visual analog scale (VAS) scores, Foot and Ankle Outcome Scores (FAOSs), ankle range of motion, and postoperative complications. Statistical analysis was conducted to compare clinical and patient-reported outcomes pre- and postoperatively. Twenty-seven patients underwent TTR for talar AVN with a mean follow-up of 22.2 months.

RESULTS

Ankle range of motion remained unchanged postoperatively. VAS pain scores improved postoperatively from 7.1 to 3.9 (P < .001). FAOSs improved postoperatively with regard to pain (P < .001), symptoms (P = .001), quality of life (P < .001), and activities of daily living (P < .001). There were 3 complications requiring reoperation in this cohort.

CONCLUSION

3D printed TTRs represent a unique surgical option for patients with severe talar AVN. Patients in this cohort demonstrated significant improvements in pain scores and patient-reported outcomes. TTR allows for symptomatic improvement with the preservation of motion in individuals with talar collapse and AVN.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Talus Fractures: Evaluation and Treatment

The talus is unique in having a tenuous vascular supply and 57% of its surface covered by articular cartilage. Fractures of the head, neck, or body regions have the potential to compromise nearby joints and impair vascular inflow, necessitating surgical treatment with stable internal fixation in many cases. The widely preferred approach for many talar neck and body fractures is a dual anterior incision technique to achieve an anatomic reduction, with the addition of a medial malleolar osteotomy as needed to visualize the posterior talar body. Percutaneous screw fixation has also demonstrated success in certain patterns. Despite this modern technique, osteonecrosis and osteoarthritis remain common complications. A variety of new treatments for these complications have been proposed, including vascularized autograft, talar replacement, total ankle arthroplasty, and improved salvage techniques, permitting some patients to return to a higher level of function than was previously possible. Despite these advances, functional outcomes remain poor in a subset of severely injured patients, making further research imperative.

Medial Femoral Condyle Periosteal Free Flap for the Treatment of Talus Avascular Necrosis

BACKGROUND

In patients with avascular necrosis (AVN) of the talus in the precollapse stage unresponsive to conservative measures, joint preservation should be considered. Good results have previously been reported for vascularized bone grafting. The medial femoral condyle (MFC) free flap has recently been introduced, which consists of corticoperiosteal bone. We present a novel surgical technique using a periosteal-only MFC (pMFC) free flap in the treatment of talus AVN.

METHODS

We retrospectively reviewed all pMFC free flaps performed from 2016 to 2018 in the precollapse stage of talus AVN. Surgical management included an ankle arthroscopy, talus core decompression, and ipsilateral pMFC free flap to the talus. Foot and Ankle Ability Measure (FAAM)-Activities of Daily Living (ADL) and visual analog scale (VAS) pain scores were evaluated, and pre- and postoperative imaging studies were assessed by a musculoskeletal-trained radiologist for all patients. Six pMFC free flaps in 5 patients were included in this case series. AVN etiology included idiopathic, posttraumatic, and sepsis-related treatment. All patients were female with an average age of 44.2 (range, 37-67) years. Average postoperative follow-up was 16.9 (range, 6-28) months.

RESULTS

Pre- to postoperative FAAM-ADL, ADL single assessment numeric evaluation, and VAS scores showed statistically significant improvement (P < .039). No reoperations or flap complications were observed. There was 1 minor complication, which included postoperative paresthesias at the pMFC harvest site. Postoperative x-rays showed no subsequent collapse, and magnetic resonance imaging (MRI) illustrated progressive improvement of bone marrow edema, decreased surrounding areas of AVN, and decreased joint effusion when compared to preoperative MRI.

CONCLUSION

The pMFC free flap is a novel modification of a previously described technique, which appears to have similar results compared to the traditional MFC free flap. It was safe and effective in the short term with excellent clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Level IV, case series.

Vascularized Pedicle Graft for Talar Osteonecrosis

Vascularized bone grafting for talar avascular osteonecrosis is indicated for patients with modified Ficat and Arlet stage I to III disease with minimal subchondral collapse. Outcomes may be more durable than core decompression alone, especially in patients with more advanced disease. Our preferred method, described in this article, involves core decompression followed by use of a vascularized cuboid pedicle graft placed in the defect. Outcomes reported in a small case series have been encouraging, with more than 80% of patients requiring no further surgery.

3D Printed Total Talar Replacement: A Promising Treatment Option for Advanced Arthritis, Avascular Osteonecrosis, and Osteomyelitis of the Ankle

Advanced ankle arthritis, avascular osteonecrosis, and osteomyelitis of the ankle remain a surgical challenge in the foot and ankle arena with limited treatment options. Multiple medical comorbidities contribute to total loss of the talus. Collapse of the talar body as a complication of total ankle arthroplasty, talectomy in infection, and septic talus necrosis or severe bone defects caused by tumor resection may result in need for total talar replacement. Ankle arthrodesis and tibiocalcaneal fusion after talectomy can produce severe disability of the ankle and foot. Total ankle replacement is a viable option for treatment of end-stage ankle arthritis in appropriate patient populations.

Current Concepts in Talar Neck Fracture Management

PURPOSE OF THE REVIEW

Talar neck fractures are a rare but potentially devastating injury, which require a comprehensive understanding of the unique osteology, vasculature, and surrounding anatomy to recognize pathology and treat correctly. The purpose of this article is to describe both classic and current literature to better understand the evolution of talar neck fracture management.

RECENT FINDINGS

Urgent reduction of displaced fractures and dislocations remains the standard of care to protect the soft tissue envelope and neurovascular structures. Delayed definitive fixation has proven to be safe. CT is the imaging modality of choice to fully identify the fracture pattern and associated injuries. Anatomic reduction and restoration of the peritalar articular surfaces are the pillars of talar neck fracture treatment. Dual incision approach with plate and screw fixation has become the modern surgical strategy of choice to accomplish these goals. Although complications such as osteonecrosis (ON) and posttraumatic arthritis (PTA) can still occur at high rates, treatment should be dictated by patient symptoms. Talar neck fractures pose treatment challenges with both initial injury and potential sequelae. Future research will determine whether modern treatment algorithms will decrease complication rate and improve patient outcome.

Tibiotalocalcaneal Arthrodesis With Bulk Talar Allograft for Treatment of Talar Osteonecrosis

Talar body osteonecrosis can be a devastating, painful condition that is difficult to manage surgically when conservative treatments have failed. With early disease, nonoperative treatments can prolong the need for operative correction in the young patient. Later stage disease with extensive involvement may require a tibiotalocalcaneal (TTC) arthrodesis to retain functionality of the limb. This situation frequently requires a structural bone graft. Using the technique described in this article, the void resulting from collapse of the talar body is filled with talar allograft, which offers a more anatomic and structurally rigid construct than previously described methods using an allograft femoral head. We have found this technique to be more resilient and successful than other methods.

LEVEL OF EVIDENCE

Level V, expert opinion.

Management of Nonunited Talar Fractures With Avascular Necrosis by Resection of Necrotic Bone, Bone Grafting, and Fusion With an Intramedullary Nail

BACKGROUND

The presence of nonunion of a talar fracture with displacement, together with complete avascular necrosis, is a challenging entity to treat.

METHODS

Twelve patients, 8 men (66.7%) and 4 women (33.3%), with nonunited talar fractures and extensive avascular necrosis of the talus were included. The average age was 27.7 years (range, 19-38 years). After exclusion of infection, the patients underwent resection of necrotic bone, bulk autograft, and fusion using an intramedullary nail. The posterior approach was used in 11 patients and the anterior approach in 1 patient. The primary outcome was solid osseous union at the ankle and subtalar level and between the talar head anteriorly and the posterior construct, as evidenced by computed tomographic examination. Functional assessment was performed with the American Orthopaedic Foot & Ankle Society score and subjective patient satisfaction Results: After a mean follow-up duration of 23 months (range, 12-60 months), solid osseous union was achieved in 8 patients (66.7%). Stable fibrous union was seen in 1 patient (8.3%). Three patients (25%) required reoperation, and osseous fusion was finally achieved. American Orthopaedic Foot & Ankle Society score improved from a mean of 39.3 (range, 12-56) preoperatively to 76.6 (range, 62-86) at last follow-up. Subjective patient satisfaction was graded good or excellent in all cases.

CONCLUSION

Resection of necrotic talar body and bulk autograft with tibiotalocalcaneal fusion by an intramedullary nail through a posterior approach was a reasonable option for the management of type IV posttraumatic talar deformity.

LEVEL OF EVIDENCE

Level IV, case series.

Development of an internally braced prosthesis for total talus replacement

Total loss of talus due to trauma or avascular necrosis, for example, still remains to be a major challenge in foot and ankle surgery with severely limited treatment options. Implantation of a custom made total talar prosthesis has shown promising results so far. Most important factors for long time success are degree of congruence of articular surfaces and ligamentous stability of the ankle. Therefore, our aim was to develop an optimized custom made prosthesis for total talus replacement providing a high level of primary stability. A custom made hemiprosthesis was developed using computed tomography and magnetic resonance imaging data of the affected and contralateral talus considering the principles and technology for the development of the S.T.A.R. prosthesis (Stryker). Additionally, four eyelets for fixation of artificial ligaments were added at the correspondent footprints of the most important ligaments. Two modifications can be provided according to the clinical requirements: A tri-articular hemiprosthesis or a bi-articular hemiprosthesis combined with the tibial component of the S.T.A.R. total ankle replacement system. A feasibility study was performed using a fresh frozen human cadaver. Maximum range of motion of the ankle was measured and ligamentous stability was evaluated by use of standard X-rays after application of varus, valgus or sagittal stress with 150 N. Correct implantation of the prosthesis was technically possible via an anterior approach to the ankle and using standard instruments. Malleolar osteotomies were not required. Maximum ankle dorsiflexion and plantarflexion were measured as 22-0-28 degrees. Maximum anterior displacement of the talus was 6 mm, maximum varus tilt 3 degrees and maximum valgus tilt 2 degrees. Application of an internally braced prosthesis for total talus replacement in humans is technically feasible and might be a reasonable procedure in carefully selected cases with no better alternatives left.