Outcomes of Tibiocalcaneal Arthrodesis in High-Risk Patients: An Institutional Cohort of 18 Patients

Abstract

Introduction

Tibiocalcaneal (TC) arthrodesis is commonly performed in patients with severe hindfoot disease. These include severe Charcot deformities, ankle malformations, chronic osteomyelitis (COM), and avascular necrosis (AVN). The talar vascular becomes disrupted to the point that the bone can no longer be salvaged. The procedure involves performing a talectomy and fusing the tibia to the calcaneus. This helps in preserving the remaining hindfoot anatomy, while allowing the patient to regain function and mobility. Our study highlights certain risk factors that influence the rate of postoperative complication after tibiocalcaneal surgery.

Materials and Methods

We retrospectively reviewed the charts of 18 patients from a single institution who underwent tibiocalcaneal between the years of 2011 and 2019. Preoperative diagnoses, comorbidities, and post-operative outcomes were noted among all patients. Then, the rates of non-union, below-knee amputations, revision surgeries, postoperative infections, and hardware failure were recorded. These data were then analyzed to determine which preoperative and perioperative factors affected postoperative outcomes for patients after tibiocalcaneal arthrodesis surgery.

Results

Nonunion was the most commonly reported complication in this series. Eight of the eighteen patients were documented to have nonunion including three patients with stable pseudarthrosis. Diabetic patients had a slightly higher incidence of nonunion (4 of 7 patients) compared to those without diabetes (4 of 11 patients). Of the nine patients diagnosed with Charcot arthropathy, five had nonunion. Three of the five individuals with a BMI ranging from 25 to 30, and four of the six individuals with a BMI of greater than 30 had a nonunion. Infection was a post-operative complication for four of the eighteen patients. Two of the four patients had multiple comorbidities in addition to chronic infections in the joint which were recurrent after surgery.

Conclusion

In conclusion, TC arthrodesis provides a viable option for high-risk patients with complicated ankle pathology who have not had successful outcomes from previous treatment. It is not without complications considering the comorbidities the patients present with before requiring this procedure. Further studies are necessary to validate the trends of outcomes and comorbidities of patients with TC arthrodesis.

Electronic supplementary material

The online version of this article (10.1007/s43465-020-00048-z) contains supplementary material, which is available to authorized users.

Introduction

Tibiocalcaneal (TC) arthrodesis with talectomy is performed when the talus is not salvageable because of significant damage, contamination, and/or gross degenerative changes. There are a variety of conditions including talar body necrosis from previous trauma [1], severe deformity [2], inflammatory arthritis [3], and Charcot neuroarthropathy [4, 5]. The talus has a unique structure and blood supply making it vulnerable to avascular necrosis (AVN) after a traumatic event. Atraumatic causes have also been connected to talus AVN. In addition to the prominence of articular cartilage, the talus has a complex blood supply [6–10]. The first documented talectomy was performed for an open talar fracture [11]. Since this procedure, talectomy performed alone has fallen out of favor due to being associated with unsatisfactory results in adults with persistent pain and residual leg-length discrepancy [12]. If traditional management fails for AVN or other damage to the talus, talectomy with subsequent tibiocalcaneal (TC) arthrodesis becomes a viable option.

Most hindfoot and ankle deformities with or without associated neuropathy may be treated with a brace. If the pathology is more severe, conservative treatment with special shoes, ankle/foot orthoses, or braces are frequently unsuccessful [13]. Generally, tibiotalocalcaneal (TTC) arthrodesis is indicated for patients in whom bracing has failed. When there is enough damage to the talus requiring removal, TC arthrodesis after talectomy is the alternative [14, 15]. Performing the talectomy in conjunction with an arthrodesis of the hindfoot provides more stability making it a better salvage option than talectomy alone. TC arthrodesis allows for some preserved motion in the midfoot, increased hindfoot stability and an overall normal cosmetic appearance of the foot; however, it causes considerable shortening of the limb [16]. A below-the-knee amputation (BKA) may be required if surgery fails to improve patient pain and mobility.

Alternatively, large bony defects in the hindfoot can be treated with tibiotalocalcaneal arthrodesis using an allograft, autograft, or tantalum material to fill gaps [17, 18]. Advantages of tibiotalocalcaneal arthrodesis with intercalary structural grafting can include restoration of limb length and improved soft tissue tension with preservation of musculotendinous function. Reported fusion rates from small case series are between 58 and 93% [18]. Disadvantages of bone block TTC arthrodesis include additional bone interfaces that are required to heal, potential for late collapse of the structural graft, and the possibility that the bone block graft either slowly or never fully incorporates into the host. Patients with multiple comorbidities are at the highest risk of impaired healing when grafts are used [17]. In contrast, tibiocalcaneal arthrodesis has been shown to have better success in high-risk patients (86–100%) [17]; however, results have shown notable shortening of the limb.

Overall, TC arthrodesis is utilized for patients with a variety of indications affecting the integrity of the talus vasculature and structure. In the literature, reports about TC arthrodesis typically focus on the type of fixation or surgical approach. There is currently a disparity in the literature about the relationship of comorbidities in high-risk patients receiving TC arthrodesis and the outcomes associated with the procedure. Other small case series exist but there is not a strong consensus about the outcomes of the procedure [13, 19]. This study aims to describe the comorbidities, demographics, and outcomes of 18 high-risk individuals who have undergone tibiocalcaneal arthrodesis. This case series is similar in size to current studies and can add to the current literature.

Materials and Methods

A retrospective analysis of the records of 18 patients who underwent a primary tibiocalcaneal arthrodesis procedure was conducted. All surgeries were performed by three fellowship-trained foot and ankle orthopedic surgeons at a single institution between January 2011 and December 2018. Average follow-up time was 1.08 years with a range of 3 months–4.25 years. Indications for surgery were Charcot neuroarthropathy, severe osteoarthritis, AVN of the talus, Planovalgus foot with peritalar dislocation (Supplementary Figure 1), traumatic conditions, aneurysmal bone cyst (giant cell rich chondroblastoma) of the talus (Fig. 1), and complex deformity of the hindfoot. Patients who were undergoing revision TC arthrodesis after a failed hindfoot fusion surgery or who had a complex open fracture were excluded from the study. Restrictions were not made based on patient demographic or comorbid conditions. Approval from the institutional review board was obtained.

Fig. 1.

Preoperative MRI and 6-month postoperative radiographs following tibiocalcaneal arthrodesis after removal of a talar aneurysmal bone cyst

Demographic information, including age, sex, and body mass index (BMI), was recorded. The average age of the patients included in the study was 48 ± 12. The average body mass index (BMI) was 29.4 ± 9.1. All preoperative diagnoses were documented.

Patient outcome was determined by analyzing common postoperative complications after primary TC arthrodesis. These included nonunion, postoperative infection, hardware failure, and below-knee amputation (BKA). The definition of union or nonunion was determined by the presence of radiographic union on plain films as read by a musculoskeletal radiologist and orthopaedic surgeon. CT scan was used for secondary confirmation of nonunion when described in radiographs. A second orthopaedic surgeon provided the final interpretation.

Results

Nonunion was the most commonly reported complication in this series (Table 1). Eight of the eighteen patients were documented to have nonunion including three patients with stable pseudarthrosis. Diabetic patients had a slightly higher incidence of nonunion (4 of 7 patients) compared to those without diabetes (4 of 11 patients). Of the 9 patients diagnosed with Charcot arthropathy, 5 had nonunion. Stable pseudarthrosis was documented in two of the patients with Charcot arthropathy with nonunion. One of the seven individuals with a BMI of less than 25, three of the five individuals with a BMI ranging from 25 to 30, and four of the six individuals with a BMI of greater than 30 had a nonunion. Hardware failure was an additional complication for two of the patients with nonunion.

Table 1.

Patient demographics that underwent tibiocalcaneal arthrodesis

Case no.	Age	Sex	BMI	Any cardiovascular disease	Diabetes mellitus	Smoking	Alcohol	Diagnosis	Etiology of arthritis	Other medical history	Preoperative osteomyelitis or infection	Bone graft used	Non-union	BKA	Hardware failure	Infection post-op
1	25	M	22.14	No	No	No	Yes	Comminuted talus fracture	Post-traumatic	None	No	Yes	Yes—some healing	No	No	No
2	40	M	24.5	Yes	No	Yes	No	Severe planovalgus foot and peritalar dislocation	Non-traumatic	Psoriatic arthritis, HTN	No	Yes	No	No	No	Yes
3	60	F	21.91	No	Yes	No	No	Charcot arthropathy	Charcot	Hypothyroid	No	Yes	No	No	No	No
4	62	M	43.33	Yes	Yes	No	Yes	Charcot arthropathy	Charcot	HTN, GERD, HLD	No	Yes	No	No	No	No
5	29	M	28.25	No	No	No	No	Aneurysmal bone cyst	Non-traumatic	None	No	Yes	No	No	No	No
6	57	F	35.33	No	No	Yes	No	Bimalleolar ankle fracture	Post-traumatic	None	Yes	No	Yes	No	No	No
7	44	M	25.5	No	No	Yes	No	Non-union right ankle/COM with sinus	Non-traumatic	None	Yes	Yes	Yes—pseudarthrosis	No	No	No
8	52	M	19.11	No	No	No	No	Cavovarus deformity	Non-traumatic	Hyperlipidemia, GERD	No	No	No	No	No	Yes
9	56	M	23.63	No	No	Yes	Yes	AVN of talus	Post-traumatic	HTN	Yes	Yes	No	No	No	No
10	45	F	27.41	Yes	Yes	No	No	Charcot arthropathy	Charcot	HTN, HLD	No	Yes	Yes—pseudarthrosis	No	No	No
11	38	F	23.73	No	No	No	No	Charcot arthropathy	Charcot	None	No	Yes	No	No	No	No
12	24	M	19.2	No	No	Yes	No	Ankle deformities due to trauma	Post-traumatic	None	No	Yes	No	No	No	No
13	41	M	38.52	Yes	Yes	No	Yes	Charcot arthropathy	Charcot	HTN	Yes	Yes	Yes—pseudarthrosis	No	No	No
14	70	M	26.12	Yes	No	Yes	Yes	Osteoarthritis	Non-traumatic	HTN	No	No	No	No	No	No
15	44	M	52.77	Yes	Yes	No	Yes	Charcot arthropathy	Charcot	HTN	Yes	No	No	No	No	No
16	41	M	38.52	No	Yes	No	Yes	Charcot arthropathy	Charcot	Osteoarthritis	Yes	No	Yes	No	Yes	Yes
17	52	M	25.01	Yes	Yes	No	No	Charcot arthropathy	Charcot	Chronic kidney disease, HTN, HBV, anemia	Yes	No	Yes	Yes	No	Yes
18	59	M	34.83	Yes	No	No	No	Charcot arthropathy	Charcot	HTN, GERD, sleep apnea	No	Yes	Yes	No	Yes	No

Infection was a post-operative complication for four of the eighteen patients. Two patients had no prior history of infection and developed infection after surgery. The other two patients had multiple comorbidities in addition to chronic infections in the joint which were recurrent after surgery. Both of these patients had nonunion and received recommendations to have below-knee amputations because of recurrent local and systemic infection related to osteomyelitis (Fig. 2).

Fig. 2.

Preoperative radiographs and 6-month postoperative radiographs after tibiocalcaneal arthrodesis with a fibular bone graft to treat chronic osteomyelitis

Discussion

The goal of this case series was to review systemic and local factors that affect postoperative outcomes after TC arthrodesis in high-risk patients. Complications after this procedure include nonunion, hardware removal, infection, and below-knee amputation. The total number of TC arthrodesis procedures performed is small due to the severe nature of the talus pathology and complex medical history of the patients. The predominate indication in this series for TC arthrodesis with talectomy is failing previous treatment for complicated ankle pathology. These included Charcot arthropathy, post-traumatic arthritis, talar avascular necrosis, congenital and acquired ankle deformities, aneurysmal bone cyst, and chronic osteomyelitis [20–22].

Patients in this series were considered high risk due to multiple systemic and local factors that have been identified as contributing to complications and poor wound healing after ankle surgery [21–24]. In one review of the predisposing factors leading to nonunion in ankle arthrodesis, patients with major medical problems (including renal failure, a significant smoking history, diabetes, and alcohol abuse) suffered an 85% nonunion rate [24]. Another study demonstrated that the need for additional surgery was more likely if two or more of the high-risk designated criteria were met, which included immunosuppression, obesity and diabetes [24]. Factors that may have contributed to post-surgical complications that were present in this series of patients include the following: Charcot arthropathy, diabetes, cardiovascular disease, chronic osteomyelitis, increased BMI, and alcohol use. Patients with multiple risk factors appear to have the highest exposure to poor outcomes. Bone healing is a complex and unique physiological process which can be disrupted by processes that are inflammatory and decrease access to oxygen and nutrients.

An increased incidence of nonunion was identified in the patients in this series with hypertension and hyperlipidemia. Peripheral vascular disease, related to hypertension and high cholesterol, can adversely affect blood flow to tissues; which can include bone and surrounding soft-tissues. This impairs delivery of oxygen, inflammatory cells, and nutrients as well as removal of carbon dioxide and other metabolites at the fracture site which is likely to be detrimental to fracture repair [25]. The quality of vascular supply to bone tends to decline with age and may be compromised by diabetes, anemia, chronic airway diseases and immobility, as well as by tumors. Reduction in vascular supply is associated with bone loss. This may be due in part to the direct effects of hypoxia, which blocks osteoblast function and bone formation but causes reciprocal increases in osteoclast genesis and bone resorption [26].

An increased incidence of nonunion in diabetic patients compared to nondiabetic patients was consistent with previous studies [22, 27]. Diabetes impairs the healing process by reducing cellular proliferation and suppressing osteoblastic activity likely impairing osseous healing diabetes is also associated with delayed enchondral ossification and impaired collagen synthesis, which leads to decreased biomechanical strength of the fracture callus. Hyperglycemia and hypoinsulinemia are factors that recent evidence has linked to bone pathophysiology in diabetics [21]. In a retrospective review of 67 ankle fusions, Perlman and Thordarson reported a higher incidence of nonunion in patients with diabetes (38%) compared with those without the disease (27%) [22].

The diabetic patients with Charcot arthropathy in this series also demonstrated the earlier reported increased incidence of nonunion in comparison to the patients without Charcot [27, 28]. Charcot arthropathy is a complication of peripheral neuropathy in which patients experience multiple microtraumas that progress to global joint destruction in the setting of a disruptive inflammatory response. The incidence of Charcot neuroarthropathy in individuals with diabetes mellitus is estimated to be a 0.1–2.5% [27]. This subgroup of individuals makes up a large percentage of those undergoing TC arthrodesis and this holds true for this cohort. Recent studies have found that performing early ankle arthrodesis for patients who have Charcot neuroarthropathy has positive outcomes including the avoidance of deep skin infections and the ability to return to independent ambulation [4, 28]. These studies are small but help to support the efficacy of the procedure.

Chronic osteomyelitis and septic arthritis were present in patients with trauma as well as patients with comorbidities such as diabetes, cardiovascular disease, and Charcot arthropathy [21, 23]. Case 2 had a history of psoriatic arthritis and hypertension, and required incision and drainage with placement of antibiotic beads in the joint space and 6–8 weeks of IV antibiotics at home 4 months after initial surgery. Case 8 had a history of tobacco abuse and alcohol use, and developed septic joint requiring incision and drainage, nail removal with antibiotics spacer insertion, and 6 months of antibiotic treatment. A below-knee amputation has been recommended for Case 16 due to a history of recurrent MRSA bacteremia/septic arthritis/osteomyelitis after injury which continued to recur postoperatively. Case 17 with an extensive history of comorbidities including immunosuppression after renal transplant, cardiovascular disease and type 1 diabetes, Charcot arthropathy, and chronic foot infection ultimately required a below-knee amputation (BKA) after right TC arthrodesis due to recurrent infection after surgery.

Frey et al. reviewed 78 patients who underwent ankle fusion and revealed a nonunion rate of 83% in patients who had an open fracture, 89% in patients with AVN and 60% in those with a history of infection, frequently involving septic arthritis or osteomyelitis [28]. Complex ankle arthrodesis success rates are decreased in the presence of infection. Once the joint becomes infected, the cartilage is at high risk for bacterial enzymatic degradation predisposing the patient to arthritic damage. As infection worsens and joint cartilage is destroyed, the infection can spread to the distal tibia and talus. In patients with currently active or recent periarticular infection, radical debridement is needed to achieve successful fusion, bone contact, stable fixation, and minimal compromise of the marginal blood supply [21, 23]. Kolker and Wilson performed a TC arthrodesis in four such patients with 100% union at 14 weeks [21].

Patients with a BMI greater than 25 had complications such as nonunion, hardware failure, and infection which may indicate a possible interference with the healing process. Although there is little evidence supporting obesity as a direct risk factor, it may lead to challenges with cast and brace fitting as well as difficulty maintaining non-weight bearing postoperatively. These circumstances have the potential to compromise the fixation and place increased mechanical load on the implants fusion site, leading to unwanted motion at the arthrodesis [23, 29].

Alcohol use was another risk factor we reviewed in the group of patients who had nonunion. Previous studies have shown an association between excessive alcohol consumption and osteoporosis, an increased fracture incidence, inhibition of osteoblast cell activity, impaired callus formation, and the development of Charcot arthropathy from alcohol-induced peripheral neuropathy [29]. Several studies have suggested an association between alcohol use and poor bone healing, but the data did not demonstrate an association independent of confounding comorbidities [22, 29]. However, one study found that a documented current or historical concern of alcohol consumption independent of other comorbidities was significantly associated with progression to nonunion after foot and ankle long bone fracture (odds ratio 2.7, 95% confidence interval 1.2–6.2) [29].

This small series did not show an increased incidence of complications in the patients who used tobacco. According to multiple studies, smoking is associated with poor clinical outcomes including lower rates of fracture union, bony fusion, and higher rates of post-operative infection and wound breakdown [30]. Several studies have shown that the results of lower limb arthroplasty, tibia shaft fracture healing, spine and hind foot arthrodesis are adversely affected by cigarette smoking [30]. The lower rate of consolidation of arthrodesis among smokers may be due to a lower oxygen carrying capacity of the bloodstream. Tobacco combustion releases tissue damaging oxygen free radicals, in addition to other non-organic particles. Inhaled carbon monoxide reduces tissue oxygenation and impairs the microcirculation within healing soft tissue and bone [31]. Recent animal studies have shown that nicotine is also a potent vasoconstrictor and impairs the revascularization of healing bone. Smoking is also shown to be detrimental to superficial wound healing. Physiological studies have shown that most of the smoking induced changes are reversible to some degree and patients are advised to quit 6–8 weeks before surgery [30, 31].

This case series report has reviewed the multiple comorbidities and pathologies which must be considered when determining how to manage high-risk patients who are candidates for TC arthrodesis. Multiple case series have been conducted to report the feasibility of various surgical applications for achieving successful TC arthrodesis. However, there is a lack of literature demonstrating which factors to consider when choosing who would be an ideal candidate for the procedure.

This study has several limitations. The first of these being that it is a retrospective descriptive study with a small sample size of 18 patients performed at a single institution. With this in mind, multicenter collaboration would allow an opportunity to increase the sample size and decrease sampling bias allowing for reliable statistical analysis and generalizability. Recommendations for future research include prospective studies designed to identify methods to improve outcomes and prevent complications.

Conclusion

In conclusion, TC arthrodesis provides a viable option for high-risk patients with complicated ankle pathology who have not had successful outcomes from previous treatment. It is not without complications considering the comorbidities the patients present with before requiring this procedure. Further studies are necessary to validate the trends of outcomes and comorbidities of patients with TC arthrodesis.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Compliance with Ethical Standards

Conflict of interest

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

Ethical standard statement

The authors had IRB approval to perform this retrospective study. There were no animal subjects.

Informed consent

For this type of study informed consent is not required.