Reconstructive Arthrodesis for Advanced Ankle and Subtalar Joint Destruction in Neuropathic and Infected Feet

TL;DR

This study examines the outcomes of reconstructive surgery for severe ankle and foot damage, finding it can be a viable alternative to amputation in some high-risk patients.

Contribution

The study provides real-world evidence on the effectiveness of limb-preserving surgery for advanced ankle and subtalar joint destruction.

Findings

Successful arthrodesis was achieved in 74% of cases.

Tibiotalocalcaneal arthrodesis with external fixation had the lowest union rate at 17%.

42% of patients experienced surgical site infections or abscesses.

Abstract

Background/Objectives: Advanced destruction of the ankle and subtalar joints due to neuropathy, chronic infection, or inflammatory conditions presents a major surgical challenge, often resulting in limb amputation. This descriptive retrospective study aims to evaluate outcomes of reconstructive surgery in patients, in whom limb preservation was prioritized over amputation despite significant soft tissue and osseous involvement. Methods: Between January 2013 and December 2022, 31 reconstructive procedures were performed on 29 patients (16 women and 13 men) with severe hindfoot deformities. Etiologies included Charcot arthropathy (55%), osteomyelitis (25%), combined pathology (10%), and rheumatoid deformity with skin defect (10%). Surgical procedures included tibiotalocalcaneal arthrodesis (39%), astragalectomy with tibiocalcaneal arthrodesis (32%), tibiotalar arthrodesis (23%), and multistage procedures (6%). Fixation methods varied based on the extent of deformity and infection. The union was assessed via radiographs and CT imaging, and outcomes were statistically analyzed using Fisher’s exact test. Results: Successful arthrodesis was achieved in 74% of cases (23/31). The union rate was significantly influenced by the type and level of fixation (p = 0.0199), with the lowest rate observed in tibiotalocalcaneal arthrodesis using external fixation (17%). Complications included surgical site infection or abscess in 42% of cases, requiring reoperation in 35%. Limb amputation was ultimately necessary in five patients (16%). Conclusions: Despite high complication rates, limb-preserving reconstructive surgery remains a viable alternative to amputation in selected high-risk patients with severe hindfoot pathology. Appropriate preoperative planning, tailored surgical strategy, and patient compliance are essential to achieving functional limb salvage and restoring weight-bearing capacity.

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1. Introduction

Advanced destruction and deformity of the ankle and subtalar joints due to neuropathy, chronic infection, or inflammatory conditions remain challenging to treat and are often associated with significant morbidity [1,2,3]. Common causes include Charcot neuroarthropathy, osteomyelitis, and severe rheumatoid deformities, which progressively lead to joint instability, bone destruction, and soft tissue compromise [4,5]. The risk of complications further increases in patients with impaired vascular supply, smoking habits, or alcohol abuse [6,7,8].

Surgical treatment of advanced ankle and subtalar joint deformities with bone destruction, osteomyelitis, or soft tissue defects remains an unresolved clinical challenge. Several factors must be considered before intervention, particularly the etiology and extent of bone loss, the condition of the soft tissues, patient comorbidities, and overall compliance [9]. The goal of reconstructive surgery is not to preserve joint mobility but to achieve stable, vital bone alignment and a plantigrade, weight-bearing limb [10]. Proper reconstruction and stabilization of the ankle and subtalar joints improve foot stability, reduce skin calluses and ulceration, and enhance the quality of life [11]. Therefore, some studies recommend early arthrodesis before severe complications develop [12,13]. Ankle and subtalar fusions include isolated tibiotalar or talocalcaneal arthrodesis, tibiotalocalcaneal arthrodesis, or astragalectomy with tibiocalcaneal arthrodesis, which is indicated when the talus is destroyed or dislocated.

Amputation is generally indicated in patients with uncontrolled infection, non-salvageable bone loss, extensive soft tissue defects that cannot be reconstructed, or when previous limb salvage attempts have failed. While below-knee amputation can effectively eliminate infection and allow early mobilization, it also results in loss of proprioception and may severely limit the patient’s ability to ambulate independently, especially in neuropathic patients with balance impairment. Deciding between limb salvage and amputation requires careful evaluation of patient expectations, risk tolerance, and potential functional outcomes. In addition, many patients prefer to preserve the limb despite the risks.

The purpose of this descriptive retrospective case series was to evaluate the outcomes of reconstructive arthrodesis in patients with severe ankle and hindfoot pathology where limb preservation was prioritized over amputation, despite extensive osseous and soft tissue involvement. We hypothesized that, despite the high risk of complications, reconstruction could achieve a functional, weight-bearing limb in the majority of patients.

2. Materials and Methods

This retrospective study included patients who underwent reconstructive surgery for ankle and subtalar joint deformities associated with bone destruction, infection, or soft tissue defects at our department between January 2013 and December 2022.

2.1. Inclusion and Exclusion Criteria

Patients were included if they had bone destruction of the ankle or subtalar joint due to Charcot neuroarthropathy, osteomyelitis, or rheumatic foot deformity with a soft tissue defect. Patients with rheumatic deformities without soft tissue defects or with other etiologies were excluded. A positive preoperative culture for an infectious agent did not preclude inclusion.

All patients underwent standardized radiographic imaging (anteroposterior, lateral, and oblique views) and a CT scan to assess the extent of bone destruction and deformity. Additional laboratory tests, including inflammatory markers (CRP and ESR), microbiological cultures, and vascular status evaluation, were performed where indicated. Surgical indication and procedure planning were decided by an orthopedic surgeon specializing in foot and ankle surgery, after comprehensive review of patient comorbidities, risk factors, and compliance.

2.2. Surgical Timing

In Charcot neuroarthropathy, surgery was performed only after resolution of the active inflammatory phase, confirmed by clinical signs and normalized inflammatory markers. In osteomyelitis cases, definitive arthrodesis was delayed until infection stabilization, ensured by targeted antibiotic therapy guided by preoperative cultures.

2.3. Surgical Procedure Selection

The level of arthrodesis and fixation method were determined according to the extent and location of bone destruction, presence and site of osteomyelitis, and soft tissue condition. Tibiotalocalcaneal arthrodesis with an intramedullary nail was preferred for extensive bone loss with intact soft tissues. Isolated tibiotalar or talocalcaneal arthrodesis was performed for limited joint destruction. External fixation was chosen in patients with significant soft tissue defects or active infection. Astragalectomy was indicated for severe talus destruction or dislocation.

2.4. Monitored Parameters

For each patient, the following data were collected: etiology, age, sex, Body Mass Index (BMI), comorbidities, risk factors, surgical procedure (type and level of arthrodesis, fixation method, use of multistage procedures), complications, reoperations, arthrodesis union, and ability to bear weight on the operated limb and infectious status (pathogen type and culture positivity pre- and postoperatively) (Table 1).

2.5. Postoperative Follow-Up

Arthrodesis union was assessed both clinically (pain-free weight-bearing and absence of abnormal mobility) and radiographically (standard X-rays) at 6 and 12 weeks postoperatively, then at monthly intervals until radiographic fusion was confirmed. If fusion was uncertain, CT imaging was performed. Patients were then monitored at six-month intervals to assess long-term outcomes, with follow-up ranging from 9 months to 11 years.

2.6. Statistical Analysis

Data were processed and analyzed using NCSS 2023 Statistical Software (NCSS, LLC, Kaysville, UT, USA). Quantitative data are reported as median and range due to non-normal distribution. Categorical variables are presented as counts and percentages. Associations between union rates and etiology or type of fusion were tested using Fisher’s exact test in contingency tables. A p-value < 0.05 was considered statistically significant.

3. Results

The study cohort comprised 29 patients (16 women and 13 men). Two patients underwent bilateral procedures, resulting in a total of 31 surgical interventions (Table 1).

The underlying causes of deformity were Charcot arthropathy in 17 cases (55%), osteomyelitis in 8 cases (25%), a combination of Charcot arthropathy and osteomyelitis in 3 cases (10%), and rheumatic foot deformity with a soft tissue defect in 3 cases (10%). The most common comorbidity was diabetes mellitus, present in 22 patients (71%), followed by hepatopathy in 9 (29%), rheumatoid arthritis in 8 (26%), and ischemic heart disease in 4 patients (13%). Notable risk factors included active smoking in 6 patients (19%), corticosteroid therapy in 5 (16%), immunosuppression in 5 (16%), and active alcohol abuse in 4 patients (13%). The mean BMI was 29.6, with a range of 19 to 48.

Pathogenic organisms were cultured preoperatively or intraoperatively in 14 cases (45%). Staphylococcus aureus was the most frequent isolate (6 cases), followed by Enterococcus faecalis and Pseudomonas aeruginosa (2 cases each). Postoperative cultures were positive in 10 cases (32%), with Staphylococcus aureus (4 cases) and methicillin-resistant Staphylococcus aureus (MRSA) (2 cases) being the most common pathogens.

The choice of the arthrodesis level and fixation method was based on the location and extent of bone destruction, the presence of osteomyelitis, and the condition of the soft tissues. Tibiotalocalcaneal arthrodesis was the most frequent procedure, performed in 12 limbs (39%); half of these used an external fixator for stabilization and the other half an intramedullary nail. Astragalectomy combined with tibiocalcaneal arthrodesis using an external fixator was carried out in 10 limbs (32%), and tibiotalar arthrodesis was performed in 7 limbs (23%). In two cases, a multistage procedure was selected.

In the first multistage case, a patient with ankle osteomyelitis underwent initial resection of the articular surfaces of the tibia and talus, placement of an antibiotic-loaded cement spacer, and stabilization with an external fixator. Seven months later, the spacer was replaced with an autograft spongioplasty (Figure 1). In the second case, involving an infected ankle nonunion, the destroyed talus and tibial articular surface were resected and filled with a cement spacer, bridged with an external fixator. Two months later, the spacer was replaced with autologous bone grafts following the Masquelet technique and the soft tissue defect was covered with a rotational flap. Five months after the initial surgery, tibiocalcaneal arthrodesis with a trabecular metal spacer nail was performed (Figure 2).

Overall, successful arthrodesis was achieved in 23 of 31 cases (74%). By etiology (Table 2, Figure S1), fusion was successful in 13 of 17 Charcot arthropathy cases (76%), 7 of 8 osteomyelitis or septic arthritis cases (88%), 1 of 3 cases with combined Charcot arthropathy and osteomyelitis (33%), and 2 of 3 cases with rheumatic foot deformity and a soft tissue defect (66%). Statistical analysis showed no significant association between union rate and etiology (p = 0.377).

Regarding the level and type of fusion (Table 3, Figure S2), tibiotalocalcaneal arthrodesis stabilized with an external fixator had the lowest union rate, healing in only 1 of 6 cases (17%). In contrast, tibiotalocalcaneal arthrodesis with an intramedullary nail healed in 5 of 6 cases (83%). Tibiocalcaneal arthrodesis with an external fixator healed in 8 of 10 cases (80%). All tibiotalar arthrodeses and both multistage procedures achieved fusion (100%). There was a statistically significant association between the union rate and the level and type of fusion (p = 0.0199), primarily due to the lower success rate of tibiotalocalcaneal arthrodesis using external fixation.

Nonunion occurred in 8 interventions (26%). In three cases, the nonunion was stable and patients could bear weight with ankle-foot orthosis. However, five patients (16%) ultimately required below-knee amputation. Case 1: A patient with preoperative Staphylococcus aureus infection underwent amputation 8 months postoperatively due to progressive foot osteomyelitis. Case 2: A patient with a persistent infected nonunion of the subtalar joint required amputation 30 months after the initial procedure. Case 3: A patient with Charcot arthropathy and a soft tissue defect developed calcaneal osteomyelitis, leading to amputation 24 months after surgery. Case 4: A patient with overlap syndrome (rheumatoid arthritis and systemic lupus erythematosus) under corticosteroids and immunosuppression developed foot gangrene; despite below-knee amputation at 9 months, the patient died of sepsis. Case 5: A patient with bilateral Charcot arthropathy, alcoholism, liver cirrhosis, and chronic pancreatitis developed osteomyelitis with skin defects; an initial below-knee amputation failed to heal, resulting in transfemoral reamputation 16 months after the primary procedure. Four of these had pre-existing infections (three with Staphylococcus aureus and one with Enterococcus faecalis); all developed postoperative infections, including MRSA in two cases.

Complicated wound healing, phlegmon, or abscess formation occurred in 13 cases (42%), mostly due to pre-existing infection. In three cases, Vacuum-Assisted Closure (VAC) therapy was sufficient for healing, but ten required reoperation. An occult tibial fracture occurred in one patient during nail insertion and was subsequently treated with intramedullary fixation. In total, reoperation was necessary in 11 interventions (35%). The mean duration from primary surgery to removal of the external fixator was 117 days (range: 87–363 days).

4. Discussion

Reconstructive surgery for advanced deformities of the ankle and subtalar joint due to Charcot neuroarthropathy, osteomyelitis, or rheumatoid arthritis remains a significant challenge and is often associated with a high complication rate. The goal of treatment is to eliminate the infection and to achieve a limb capable of bearing weight in the plantigrade position. Although amputation may offer a definitive solution, it can severely limit independent ambulation, especially in neuropathic patients with compromised balance.

In our high-risk cohort of 31 interventions, despite significant comorbidities, the presence of infection, and soft tissue defects, the limb was preserved, and weight-bearing capacity was restored in 26 limbs. This makes our study one of the largest single-center series addressing this topic.

Previous studies have reported similarly high complication rates for ankle and subtalar arthrodesis in high-risk patients. Love et al. reported nonunion in 8 of 18 patients and wound complications in 4 cases [14]. Perlman et al. observed nonunion rates of 38% in diabetic patients and 27% in non-diabetics [15]. Other reports highlight a higher risk of reoperation when patients present with multiple risk factors such as diabetes, immunosuppression, or obesity [3,16]. In our cohort, the overall nonunion rate was 26% and infection-related complications occurred in 42% of interventions. Ultimately, five patients required amputation, highlighting the need for careful patient selection and thorough preoperative planning [17]. Patients should be informed about the considerable risk of complications, including delayed union, persistent infection, or even eventual amputation despite multiple surgical attempts. Strict compliance with postoperative care, wound hygiene, and frame management is crucial, but can be particularly demanding for neuropathic patients [11].

Charcot neuroarthropathy is characterized by progressive joint instability, deformity, soft tissue ulceration, and frequent secondary osteomyelitis [18]. Conservative management during the acute inflammatory phase includes immobilization and off-loading, but surgery is indicated once the inflammation subsides if the foot cannot be maintained in a plantigrade position.

For osteomyelitis-related deformity, the primary aim is infection control using broad-spectrum antibiotics, targeted therapy once cultures are available, and debridement of necrotic bone, followed by definitive arthrodesis once infection has resolved [19].

In our series, the choice of arthrodesis level and fixation method was tailored to the extent of bone destruction, infection, and soft tissue status. Tibiotalar arthrodesis was preferred for isolated tibiotalar joint damage, while tibiotalocalcaneal arthrodesis was used when both the tibiotalar and subtalar joints were involved or when greater mechanical stability was needed, such as in cases with severe osteoporosis. Astragalectomy with tibiocalcaneal fusion was reserved for severe talar destruction or dislocation [20,21,22]. While astragalectomy can correct deformity, it often results in limb shortening [23]. In one exceptional case in our cohort, a trabecular metal spacer nail was used to maintain leg length after talus removal.

A total of 21 interventions in our cohort were stabilized using an external fixator. This method offers important advantages, particularly in cases with soft tissue defects or active infection: by anchoring the fixator into healthy bone, it provides reliable reduction, compression at the fusion site, and stable immobilization even in compromised bone conditions [24,25,26]. Moreover, wound care is facilitated because skin defects can be dressed more easily, and adjunctive therapies such as Vacuum-Assisted Closure (VAC) can be effectively applied [27,28]. However, external fixation comes with notable drawbacks, especially the frequent occurrence of pin tract infections, which require diligent local care and can complicate healing [18,29]. In our study, this was evident in the subgroup of patients who underwent tibiotalocalcaneal arthrodesis stabilized with an external fixator—this subgroup had the lowest observed fusion rate, with successful union achieved in only 1 of 6 cases. Most patients in this group presented with a combination of Charcot neuroarthropathy, septic arthritis, and insufficient soft tissue coverage—a complex scenario that often represents a borderline indication for limb salvage. Our average duration of external fixation was 117 days (approximately 16.7 weeks). After fixator removal, we routinely applied a custom-made plastic orthosis for an additional 6 to 12 weeks to protect the fusion site during the final consolidation phase. This contrasts with other published series, where the fixator typically remains in place for 18 to 27.7 weeks without subsequent bracing [2,14,30]. We believe that the additional immobilization after frame removal may contribute to improved mechanical stability, but this approach also demands strict patient compliance and extended rehabilitation.

This study has several limitations. First, it is a retrospective descriptive case series without a control group, which limits the ability to draw direct causal inferences. Second, the sample includes a heterogeneous patient population with various comorbidities, which may affect the generalizability of the results. Third, the absence of patient-reported outcome measures and standardized functional scoring restricts the assessment of long-term functional results. Despite these limitations, the study provides valuable insight into the feasibility and challenges of limb salvage procedures in complex hindfoot pathology.

5. Conclusions

In conclusion, our study highlights the importance of meticulous preoperative planning, including thorough assessment of soft tissues, neurovascular status, and bone defects, to achieve successful surgical management of complex ankle and foot deformities. For patients with extensive bone destruction but intact soft tissues, we recommend tibiotalocalcaneal arthrodesis with an intramedullary nail for optimal mechanical stability. In cases with limited joint destruction, isolated tibiotalar or talocalcaneal arthrodesis is sufficient. An external fixator remains a valuable option for achieving stable arthrodesis in patients with soft tissue defects and active infection. Astragalectomy should be reserved for cases with severe talus destruction or dislocation.

Despite the high risk of complications, reconstructive surgery offers a viable alternative to amputation for selected high-risk patients, providing the potential to preserve the limb and restore weight-bearing function. Careful patient selection, individualized surgical strategy, and strict postoperative care are key to maximizing treatment success and maintaining patient mobility.