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Charcot foot arthropathy is a severe complication of diabetes mellitus, characterized by progressive destruction of bones, joints, and soft tissues of the foot and ankle . Deformity and foot instability ensuing from this process is associated with a significantly increased risk of ulceration, infection, and, ultimately, major amputation . This often mandates surgical intervention to correct deformity and restore function to the foot while attempting to avoid further complications. Surgery, however, is intrinsically risky in patients with diabetes, particularly concerning wound-healing, infections and cardiovascular complications, which can be significantly increased due to poor glycaemic control .

The perioperative glycaemic level is a very important factor in the reduction of postoperative complications in patients with diabetes undergoing elective foot and ankle surgery. National guidance recommend a HbA1c value of less than 8.5 % (IFCC 69 mmol/mol) before an elective surgery . This proves quite difficult to achieve in those patients with a Charcot foot deformity as most of them suffer from poor mobility, inability to exercise and a subsequent high body mass index (BMI) . In addition, Charcot foot deformities often present with infected ulcers that contribute to hyperglycaemia and a poor glycaemic control. Unlike those diabetic foot presentations with severe infection or ischemia, that require urgent interventions to save the limb, Charcot foot reconstructions are considered as non-urgent and booked as elective procedures in the National Health Service (NHS). However, we recognise these procedures as ‘time-critical’ as prolonged delay or repeated cancellations due to the raised HbA1C above the recommend threshold can lead to poor outcomes and a limb loss .

In our unit, all patients undergoing elective Charcot foot reconstructions are supported by our multidisciplinary diabetic foot team (MDFT) with the aim of achieving the target HbA1C level of less than 8.5 %. However, despite these measures, if the HbA1C level remains above 8.5 %, we still continue to proceed with these time-critical elective procedures. We have performed a study comparing the outcomes of Charcot foot reconstructions among the patients who had achieved the pre-operative target HbA1C level and those who did not.

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The aim of the study was to identify the proportion of patients undergoing elective Charcot foot reconstructions with history of diabetes that achieved the pre-operative target HbA1C value of below 8.5 %, evaluate the post-operative outcomes and compare the outcomes between those that achieved the target value and against that did not.

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We retrospectively evaluated the prospectively collected data on consecutive patients with diabetes, who underwent elective Charcot foot reconstructions under a single consultant over a 22-month period, with a minimum follow-up of 12 months post-surgery. Patients’ data, including demographics, preoperative HbA1c levels, types of surgical procedures, and postoperative outcomes, were collected and analysed. We recorded the pre-operative comorbidities such as hypertension, (defined as a blood pressure levels above 140/80 mmHg, or patients already on antihypertensive treatment), hypercholesterolemia (defined as an LDL cholesterol level of ≥130 mg/dl (3.35 mmol/l) or patients already on lipids lowering treatment), obesity (defined as a body mass index of more than 30), atrial fibrillation, ischemic heart disease and cerebrovascular disease. A thorough clinical examination of the foot and ankle focusing on the deformity, instability, soft-tissue contractures, muscle imbalance, and joint range of motion status was done.

Radiological imaging for preoperative planning included weight bearing dorsoplantar and lateral radiographs of both feet and anteroposterior and lateral radiographs of the ankle. CT imaging and 3D printed plastic model of the affected foot/ ankle were performed for surgical planning of complex presentations. All patients underwent vascular assessment with ABPI and arterial Doppler before the procedure to ensure adequate vascular supply pre-surgery . Those with inadequate vascular supply underwent a revascularisation procedure prior to Charcot reconstruction.

We reviewed the glycaemic control of patients at 12 months post-reconstruction, along with any postoperative complications recorded during the follow up. The clinical outcomes including postoperative complications, ambulation and radiological results, were categorized and analysed.

Statistical analysis was performed using IBM SPSS Statistics for windows (version 26). Preoperative and postoperative HbA1c levels and the outcomes were compared between patients who achieved the preoperative HbA1c target of 8.5 % and those who did not. Continuous variables, such as HbA1c levels, were expressed as mean ± standard deviation (SD) and analysed using paired t -tests. Categorical variables, such as complication rates, were expressed as percentages and analysed using the chi-square test. A p-value of < 0.05 was considered statistically significant.

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Effective preoperative management in optimizing surgical outcomes in patients with Charcot foot deformity is especially important in those with suboptimal glycaemic control. The multidisciplinary foot team (MDFT) plays a crucial role in providing comprehensive preoperative care. In our diabetic foot unit, the MDFT includes diabetologists, orthopaedic surgeons, podiatrists, microbiologists, physiotherapists and specialized nurses, working together in providing holistic patient care ^,, .

The preoperative management incorporates a detailed assessment of the general health status of the patients, including diabetes control, in particular, the HbA1c level, fasting and post prandial blood glucose levels, and evaluation of diabetes related complications, such as nephropathy, neuropathy, or cardiovascular disease. Those patients with the HbA1c above the target levels had received an individualised plan from the MDFT to optimize their glycaemic control as much as possible before surgery .

Improving glycaemic control involves dietary modification, alteration of diabetes medications and initiation or intensification of insulin treatment. The patients are also educated on foot hygiene, monitoring for any signs of infection or ulceration, and adherence to the prescribed treatment regimen and offloading ^, .

The diabetic foot ulcers can be classified as low, moderate and high risk . Based on the ulcer risk level the frequency of follow-ups is arranged and appropriate management instituted . Infection control plays a crucial role in ulcerated Charcot feet, and this includes debridement, monitoring of the inflammatory markers such as CRP and WBC count and administering targeted antibiotic according to cultures from tissue samples .

Given the time-critical nature of Charcot foot reconstructions, surgery often cannot be delayed waiting for optimal glycaemic control. Reduced mobility is a significant factor in these patients’ failure to reach perioperative HbA1c target, as their poor level of mobility allows for very little physical activity . In these circumstances, the decision made by the MDFT to proceed with surgery balances the risks of suboptimal glycaemic control against the probable benefits of timely surgical intervention. Coupled with this, the team makes the patient fully aware of the possible risks and benefits, and the perioperative care formulated to reduce the risks associated with poor glycaemic control .

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The aim of Charcot foot reconstruction is to achieve a stable and plantigrade foot that is infection and ulcer-free and allows full weight bearing in a custom pair of footwear with custom insoles. A detailed surgical planning is made for each patient based on individual presentation ^,, . The deformity is corrected by releasing contracted soft tissues and performing wedge/rhomboid bone resections on the convex side. The corrected deformity is stabilised with internal fixation devices following our established principle of ‘a durable long-segment and rigid internal fixation in optimal bone opposition’. In the presence of any previous history of ulceration or local infection, an adjuvant antibiotic loaded injectable bio-composite material is instilled in the bone voids and around osteotomies . Appropriate soft tissue balancing is achieved by performing tendon transfers, as required, before the wound closure.

If there is an associated actively infected foot ulcer, we perform the reconstruction as a two-staged procedure- the first stage involves debridement of infected ulcer and bones, application of local antibiotic eluting calcium preparation and temporary stabilisation of any unstable part with threaded wires fixation. The second stage is performed after clinical and serological evidence of eradication of infection, usually in 6 weeks. This included definitive deformity correction, internal fixation using the standard principles and application of local antibiotic eluding calcium preparation . Post-operatively, the operated limb is offloaded in a total contact cast, non-weight bearing for about 3 months following which, patients can transition into custom shoes when adequate bone healing response is noted on radiographs .

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Postoperative management is equally vital for successful Charcot foot reconstructions. The postoperative care plan is individualized to each patient’s needs; it must address wound care, proper offloading, glycaemic control, infection control, and rehabilitation .

Wound care is very important in the immediate postoperative period. Patients are closely monitored by the MDFT for any signs of wound infection. Dressings are changed accordingly, and signs of infection addressed immediately with interventions, which include antibiotics and local debridement as needed .

Good glycaemic control is important during the post-operative phase because it facilitates wound healing and reduces complications. The patient’s blood glucose levels are closely monitored, with modification of diabetes medications and insulin therapy as appropriate. Patients receive continuous education from the MDFT on how to manage diabetes effectively during recovery .

The rehabilitation process is a vital part of postoperative care. Patients are advised to participate in physiotherapy, which helps augment mobility and strength. Such progressive rehabilitation can be undertaken with non-weight-bearing exercises that go on to become weight-bearing activities, depending on bone healing response .

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A total of 18 diabetic patients underwent Charcot foot reconstructions between October 2020 and August 2022 under the senior author. The cohort consisted of 11 males and 7 females, with a mean age of 56.7 years (range 34–77 years). Table 1 is a summary of the patient baseline demographics; 10 patients had type 1 diabetes and 8 patients type 2 diabetes. We recorded the following comorbidities among those patients before surgery: Hypertension , hypercholesterolemia , obesity , and atrial fibrillation .

The waiting time to surgery was defined as time between when the patient was listed for surgery and the date of actual surgery performed at our hospital. The mean duration for waiting time to surgery was 11 months with a minimum waiting duration of 6 months and a maximum of 14 months. The types of reconstructions included 8 midfoot, 2 hindfoot, and 8 combined hindfoot and midfoot surgeries. All patients had satisfactory vascular supply assessed by ABPI and ultrasound Doppler performed within 2 months prior to surgery.

Preoperative glycaemic control was variable before surgery, with HbA1c levels ranging from 5.4 % to 11.8 % with a mean of 7.9 %. Target HbA1c was not achieved in 7 patients. The mean HbA1c in the non-target group was 9.6 % and in the target group 7.2 %. The mean HbA1c levels postoperatively was 6.4 % in the target group and 8.9 % in the non-target group, indicating an overall improvement in glycaemic control.

With regards to the pre-surgical infection status, 11 patients had active ulcers which were managed with local debridement, oral antibiotics and total contact casting prior to reconstruction that resulted in full ulcer healing. There were two patients who presented with actively infected ulcers that required two-stage reconstructions. These two patients earlier had developed ulcerated deformities and the ulcers improved with conservative management. Subsequently, while already on the waiting list for surgery they developed infection and hence were admitted for 1st stage procedure which was done urgently.

Early postoperative complications were observed in 4 patients, but all resolved with conservative treatment. These included wound infection, wound discharge and a new ulceration among the patients in target group, and an infected blister in the non-target group. All these resolved with local debridement, antibiotics, and close monitoring of blood glucose levels.

At the 12-month follow-up, no deaths were recorded, and there were no major cardiovascular complications such as myocardial infarction (MI) or transient ischemic attacks (TIA). Repeat surgical procedure was needed in 3 patients for metal work related complications. No significant differences in complication rates were observed between patients who met the preoperative HbA1c target and those who did not.

Radiological assessments showed satisfactory bone healing and fusion in 15 cases. Metalwork failure was observed in two cases, with one showing no progression of deformity whereas the second patient developed recurrence of deformity that was managed conservatively. One patient developed non-union of the fused part with no metal work failure or deformity recurrence. Table 2 is a summary of post operative complications and outcomes.

Clinically, most patients demonstrated significant improvements in mobility and functional status. Specifically, 11 patients were independently mobile both indoors and outdoors in custom shoes, 3 patients were independently mobile indoors and used wheelchair for outdoor mobilisation, 3 patients were independently mobile indoors with no support and required crutches for outdoor mobilisation, and 1 patient used a Zimmer frame for mobility.