A new form of surgical treatment for patients with avascular necrosis of the talus and secondary osteoarthritis of the ankle

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 Radiographic Outcomes of Vascularized Pedicle Bone Grafting in Foot: A Case Series

Background Navicular nonunion and talar avascular necrosis may result from limited blood supply predisposing to injury and impaired healing. Vascularized pedicled bone grafting is a promising adjunct to treat these challenging conditions, offering the susceptible diseased site structural and vascular support. We report the early radiographic and clinical outcomes of vascularized pedicled bone grafting in patients with navicular nonunion, talonavicular fusion nonunion, and talar avascular necrosis.

Methods Patients with navicular nonunion, talonavicular fusion nonunion, or talar avascular necrosis who underwent vascularized pedicled bone grafting at our institution from January 2014 to February 2019 were retrospectively identified. Radiographic evidence of healing was monitored postoperatively as defined by: progression toward union on CT for nonunion and absence of disease progression on MRI or CT for avascular necrosis. Surgical complications and need for additional surgeries were documented.

Results Eight patients were included who underwent vascularized pedicled bone grafting for navicular nonunion (N = 5), talonavicular fusion nonunion (N = 1), and talar avascular necrosis (N = 2). Average clinical follow-up was 10.8 months (range 4–37). All patients had 4 or more months postoperative radiographic follow-up with MRI or CT. Seven of eight patients demonstrated evidence of radiographic healing. One patient required additional surgery due to external fixator pin site infection. No other complications were reported.

Conclusion Our results corroborate prior case series suggesting vascularized pedicled bone grafting is a safe and reliable procedure for treating navicular nonunion, talonavicular fusion nonunion, or talar avascular necrosis with potential to spare or delay need for salvage procedures in the younger patient population.

Level of Evidence The evidence level is Level V.

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.

Three dimension printing talar prostheses for total replacement in talar necrosis and collapse

Background

Reconstructing bone structures and stabilizing adjacent joints are clinical challenges in treating talar necrosis and collapse (TNC). 3D printing technology has been demonstrated to improve the accuracy of talar replacement. This study aimed to evaluate anatomical talar replacement and the clinical results.

Methods

Nine patients with TNC were enrolled between 2016 and 2020. The prosthetic shape and size were designed by CT post-processing and mirror symmetry technology. The clinical outcomes included radiographic parameters of the forefoot, hindfoot, and ankle alignment, ankle activity, recurrent pain, and peri-operative complications.

Results

After a mean follow-up of 23.17 ± 6.65 months, degenerative arthritis and prosthetic dislocation and other complications were not observed on plain radiographs. Each 3D-printed talar prosthesis was placed in the original anatomical position. The parameters which have significant changes pre-operative and post-operative are as follows: talar height, 27.59 ± 5.99 mm and 34.56 ± 3.54 mm (95% CI − 13.05 to − 0.87, t = 2.94, P = 0.032) and Meary’s angle, 11.73 ± 4.79° and 4.45 ± 1.82° (95% CI 1.29~22.44, t = 2.89, P = 0.034). The AOFAS hindfoot score improved from 26.33 ± 6.62 to 79.67 ± 3.14 at the final follow-up (95% CI 43.36~63.30, t = 13.75, P = 0.000). The VAS score decreased from 6.33 ± 1.03 to 0.83 ± 0.75 (95% CI 4.40~6.60, t = 12.84, P = 0.000). The post-operative satisfaction scores regarding pain relief, activities of daily living, and return to recreational activities were good to excellent, and the change of activity range was statistically significant.

Conclusions

The 3D printing patient-specific total talar prostheses allowed anatomical reconstruction in TNC. This novel treatment with 3D-printed prostheses could serve as a reliable patient-specific alternative in TNC.

Vascularized Medial Femoral Condyle Autografts for Osteochondral Lesions of the Talus: A Preliminary Prospective Randomized Controlled Trial

Talar osteochondral lesions (OCLs) lead to progressive stages of talar destruction. Core decompression with cancellous bone grafting (CBG) is a common treatment for Berndt and Harty stages II and III. However, in a subset of patients, talar revascularization may fail. Surgical angiogenesis using vascularized medial femoral condyle (MFC) autografts may improve on these outcomes. These 2 treatment strategies were directly compared via a prospective preliminary randomized trial including 20 participants with talar core decompression followed by either cancellous (CBG group, n = 10) or vascularized MFC (MFC group, n = 10) bone grafting. Outcome analysis was performed with visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Lower Extremity Functional Scale (LEFS), and contrast-enhanced magnetic resonance imaging (MRI) scans. At 12 months of follow-up, the mean VAS score was reduced from 6.6 ± 2.5 preoperatively to 4 ± 1.9 in the CBG group and from 5.2 ± 2.9 preoperatively to 1 ± 1.1 in the MFC group (p < .001). The LEFS improved from 53.4 ± 13.1 to 62.6 ± 16.2 CBG and from 53 ± 9.3 to 72.4 ± 7.4 MFC (p = .114). AOFAS improved from 71 ± 12.1 to 84.1 ± 12.5 in CBG and from 70.5 ± 7.4 to 95.1 ± 4.8 in MFC (p = .019). The MRI scans in the CBG group demonstrated 9 partial malperfusions and 1 hypervascularized bone graft, whereas the MFC group had 8 well-vascularized grafts incorporated into the talus and 1 partial malperfusion. Vascularized MFC autografts provide superior pain relief along with improvement of physical function in patients with talar OCL stage II and III compared with CBG. To confirm these promising results, further multicenter randomized controlled trials are required.

Natural History of Avascular Necrosis in the Talus: When to Operate

Avascular necrosis (AVN) of the talus bone is a progressive and debilitating consequence of trauma or exposure to a variety of risk factors. The Ficat classification describes current understanding of the natural history of AVN, including preclinical, preradiographic, precollapse, postcollapse, and arthritic stages. The size and location of the avascular region likely determines risk of progression; however, symptoms do not correlate with stage. Patients may be minimally symptomatic despite diffuse involvement for long periods. Joint-sparing strategies have shown promise but do not universally prevent progression of the disease. When bone structure fails, joint-sacrificing strategies may be required.

Stem cell therapy in early post-traumatic talus osteonecrosis

PURPOSE

Avascular necrosis of the talus is one of the most notable complications associated with talar neck fractures with frequent evolution of the osteonecrosis into a difficult arthrodesis. We tested whether the injection of bone marrow mesenchymal stem cells (MSCs) could improve the repair process of the osteonecrosis.

MATERIAL AND METHODS

Forty-five early (without collapse) post-traumatic talus osteonecroses (group 1; study group) were treated between 1995 and 2012 with percutaneous injection of progenitor cells (autologous bone marrow concentrate from the iliac crest). The number of MSCs transplanted in each ankle of group 1 was 124 × 103 cells (range 101 × 10³ to 164 × 10³ cells). The evolution of these osteonecroses treated with autologous bone marrow implantation was compared with the evolution of a control group of 34 talar osteonecroses without collapse and treated with only core decompression (group 2; control group) between 1985 and 1995. The outcome was determined by progression in radiographic stages to collapse, by the need of arthrodesis, and by the time to successfully achieve fusion for patients who needed arthrodesis.

RESULTS

For the 45 ankles with autologous concentrate bone marrow grafting, collapse frequency was lower (27%, 12 among 45 versus 71%, 24 among 34; odds ratio 0.1515, 95% CI 0.0563-0.4079; P = 0.0002) and follow-up showed longer duration of survival before collapse or arthrodesis, compared to 34 ankles of the control patients with core decompression alone. Furthermore, the time to successfully achieve fusion after arthrodesis was significantly shorter in patients treated with bone marrow progenitors as compared with the other ankles, which had core decompression alone.

CONCLUSION

In our study the early conservative surgical treatment with autologous bone marrow grafting improved the natural course of the disease as compared with core decompression alone.

Management Options in Avascular Necrosis of Talus

Avascular necrosis (AVN) of the talus can be a cause of significant disability and is a difficult problem to treat. The most common cause is a fracture of the talus. We have done a systematic review of the literature with the following aims: (1) identify and summarize the available evidence in literature for the treatment of talar AVN, (2) define the usefulness of radiological Hawkins sign and magnetic resonance imaging in early diagnosis, and (3) provide patient management guidelines. We searched MEDLINE and PUBMED using keywords and MESH terminology. The articles' abstracts were read by two of the authors. Forty-one studies met the inclusion criteria of the 335 abstracts screened. The interventions of interest included hindfoot fusion, conservative measures, bone grafting, vascularized bone graft, core decompression, and talar replacement. All studies were of Level IV evidence. We looked to identify the study quality, imprecise and sparse data, reporting bias, and the quality of evidence. Based on the analysis of available literature, we make certain recommendations for managing patients of AVN talus depending on identified disease factors such as early or late presentation, extent of bone involvement, bone collapse, and presence or absence of arthritis. Early talar AVN seems best treated with protected weight bearing and possibly in combination with extracorporeal shock wave therapy. If that fails, core decompression can be considered. Arthrodesis should be saved as a salvage procedure in late cases with arthritis and collapse, and a tibiotalocalcaneal fusion with bone grafting may be needed in cases of significant bone loss. Role of vascularized bone grafting is still not defined clearly and needs further investigation. Future prospective, randomized studies are necessary to guide the conservative and surgical management of talar AVN.

Arthrodesis of the ankle using an anterior sliding tibial graft for osteoarthritis secondary to osteonecrosis of the talus

Aims

This retrospective cohort study compared the results of vascularised and non-vascularised anterior sliding tibial grafts for the treatment of osteoarthritis (OA)of the ankle secondary to osteonecrosis of the talus.

Patients and Methods

We reviewed the clinical and radiological outcomes of 27 patients who underwent arthrodesis with either vascularised or non-vascularised (conventional) grafts, comparing the outcomes (clinical scores, proportion with successful union and time to union) between the two groups. The clinical outcome was assessed using the Mazur and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores. The mean follow-up was 35 months (24 to 68).

Results

The mean outcome scores increased significantly in both groups. In the vascularised graft group, the mean Mazur score improved from 36.9 to 74.6 and the mean AOFAS scale improved from 49.6 to 80.1. In the conventional arthrodesis group, the mean Mazur score improved from 35.5 to 65 and the mean AOFAS scale from 49.2 to 67.6. Complete fusion was achieved in 13 patients (76%) in the vascularised group, but only four (40%) in the conventional group. The clinical outcomes and proportion achieving union were significantly better in the vascularised group compared with the conventional arthrodesis group, although time to union was similar in the two groups. Take home message: Vascularised sliding tibial grafts may be used to achieve arthrodesis in patients with OA of the ankle secondary to osteonecrosis of the talus. Cite this article: Bone Joint J 2016;98-B:359–64.