Introduction-Diabetic Foot Osteomyelitis
Diabetic foot osteomyelitis is one of the most severe complications of the diabetic foot and is closely associated with major amputation, prolonged hospitalization, and increased mortality. Osteomyelitis occurs in approximately 10–15% of moderate and up to 50% of severe diabetic foot infections, while its presence nearly doubles the risk of limb loss (1). Therefore, its effective management requires early diagnosis and a coordinated medical and surgical approach within a multidisciplinary diabetic foot team.
Pathogenesis / Pathophysiology of Diabetic Foot Osteomyelitis
Diabetic foot osteomyelitis typically develops through the contiguous spread of infection from a chronic foot ulcer to the underlying bone. Peripheral neuropathy leads to loss of protective sensation, foot deformities, and abnormal pressure distribution across the plantar surface, predisposing to skin breakdown and ulcer formation over bony prominences. Peripheral arterial disease and microvascular dysfunction further impair tissue perfusion and host defense mechanisms, facilitating the penetration of microorganisms into deeper tissues (2).
Once microorganisms reach the bone, the infection triggers an intense inflammatory response, accompanied by vascular thrombosis, increased intraosseous pressure, and disruption of local blood supply. These processes lead to ischemia and necrosis of bone segments, with the formation of necrotic bone fragments (sequestra) surrounded by reactive new bone (involucrum), which are characteristic findings of chronic osteomyelitis. The combination of neuropathy, ischemia, and impaired immune response in patients with diabetes promotes the chronicity of infection and the progressive destruction of bone.
Diagnosis and Preoperative Assessment of Diabetic foot Osteomyelitis
Diagnosis and preoperative assessment aim to confirm the presence of osteomyelitis, determine the extent of bone involvement, and evaluate the vascular status of the limb prior to surgical intervention (3). Clinical examination includes the probe-to-bone test, which, when positive in a high-risk ulcer, strongly suggests the presence of underlying bone infection (4). Plain radiography is usually the first imaging modality and may reveal bone destruction, periosteal reaction, or foot deformities. Magnetic resonance imaging (MRI) is considered one of the most sensitive imaging techniques for assessing the extent of osteomyelitis and the involvement of soft tissues, and is particularly useful for preoperative planning (5).
Bone biopsy for histological examination and culture may be performed when clinical and imaging findings are inconclusive or when targeted microbiological identification is required. The vascular status of the limb is assessed by measuring the ankle–brachial index (ABI) and, when necessary, with duplex Doppler ultrasound to evaluate arterial perfusion. In selected patients with suspected significant peripheral arterial disease, digital subtraction angiography may be performed for detailed mapping of the arterial tree and planning of endovascular or open revascularization (6).
In cases of significant ischemia, revascularization of the limb should precede surgical management of osteomyelitis in order to restore adequate perfusion and improve tissue healing potential. Finally, careful assessment of soft tissue infection—including erythema, edema, abscess formation, or necrosis—is essential for determining the extent of surgical debridement and guiding perioperative antibiotic therapy.
Indications for Surgical Managemen of Diabetic foot Osteomyelitis
Surgical intervention is indicated in patients with diabetic foot osteomyelitis when there is necrotic or non-viable bone, extensive bone destruction, or failure of conservative treatment with antibiotics. The presence of an abscess, extension of infection into the surrounding soft tissues, exposure of bone within the ulcer, or progressive worsening of infection despite appropriate antimicrobial therapy are also common indications for surgery (7).
In addition, mechanical instability of the foot, severe deformities, or recurrent ulcers associated with infected bone may require surgical correction. The primary goal of surgical treatment is to eradicate the infection through removal of the infected and necrotic bone, while preserving as much as possible the functional architecture of the foot.
Surgical Management of Diabetic Foot Osteomyelitis
The surgical management of diabetic foot osteomyelitis aims to eradicate infection while preserving a functional and stable foot capable of weight-bearing. Initial surgical debridement includes removal of necrotic soft tissue, biofilm, and clearly non-viable bone, along with obtaining bone samples for microbiological culture. Bone resection is typically extended until healthy, bleeding bone is identified, ensuring that the remaining bone margins are free of infection. The residual healthy bone is left embedded within the final surgical wound and covered by viable soft tissues, avoiding exposure (7,8).
When feasible, conservative resection of the infected bone segment is performed (e.g., phalangectomy, metatarsal head resection, or joint resection) without the need for formal amputation. These limb-preserving procedures have been associated with high healing rates and a reduced need for major amputation.
In cases of extensive infection or significant bone destruction, minor amputations may be required, such as toe amputation, ray amputation, or transmetatarsal amputation. The goal is to remove non-salvageable tissue while preserving as much limb length as possible and maintaining the biomechanical stability of the foot. These procedures are part of broader limb-salvage strategies, where limited resections or distal amputations, combined with appropriate antibiotic therapy, can achieve long-term remission of osteomyelitis and high rates of limb preservation, avoiding more proximal amputations in the majority of patients (7,8).
Postoperative Management
Postoperative management aims to prevent recurrence of infection and achieve stable wound healing. During surgery, samples from the resected bone and surrounding tissues are obtained for microbiological culture, in order to guide targeted antimicrobial therapy. Systemic antibiotic treatment is subsequently adjusted according to intraoperative culture results and administered for an appropriate duration, depending on the extent of infection and the adequacy of bone resection.
Local wound care includes regular clinical assessment and, when necessary, repeat surgical debridement, maintenance of a moist wound environment, and close monitoring for early signs of infection recurrence (9,10). In selected cases, negative-pressure wound therapy may be used to promote granulation tissue formation and control local infection prior to definitive wound closure.
Strict off-loading of the affected limb, using Total Contact Cast (TCC), removable immobilization boots, or specialized postoperative/therapeutic footwear, is essential for protecting the surgical site and preventing new ulcer formation. In parallel, optimization of glycemic control, nutritional status, and cardiovascular risk factors contributes to improved immune function and tissue healing.
Finally, close postoperative follow-up is required, including clinical evaluation and, when indicated, imaging studies for early detection of possible recurrence of osteomyelitis and timely adjustment of treatment.
Conclusions
Diabetic foot osteomyelitis is a complex clinical entity that requires early diagnosis and a comprehensive therapeutic approach. Successful management is based on the combination of appropriate antimicrobial therapy, surgical intervention when indicated, proper off-loading, and close follow-up. The collaboration of a multidisciplinary team is crucial for improving outcomes and preserving the limb.
