Pilot Experience on the Use of S54P4 Bioactive Glass in the Surgical Management of Diabetic Foot Osteomyelitis

Gel Based on Hydroxyethyl Starch with Immobilized Amikacin for Coating of Bone Matrices in Experimental Osteomyelitis Treatment

A polysaccharide gel containing covalently bound amikacin, a broad-spectrum antibiotic, was produced by using epichlorohydrin-activated hydroxyethyl starch (HES). The structure of the polymers was analyzed by 13C and 1H nuclear magnetic resonance (13C NMR and 1H NMR) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The sites of covalent attachment of amikacin to the epoxypropyl substituent and the HES backbone were determined. The antibacterial activity of the polymer was evaluated in vitro using the agar well diffusion method with the Staphylococcus aureus P209 strain. It was demonstrated that the polymer retained activity in the presence of bacterial amylase, which is released upon bacterial attack. The gel was applied for coating pores and surfaces of a biocomposite material based on a xenogenic bovine bone matrix. In vivo experiments showed the effectiveness of utilizing amikacin-containing biocomposite bone-substitute materials in the treatment of experimental osteomyelitis in rats using objective histological control and X-ray tomography.

Diabetic Pedal Osteomyelitis and Its Treatment

Diabetes is a fast-growing chronic metabolic disorder that is widely associated with foot ulcers. The major challenge among these ulcers is wound infections, altered inflammatory responses, and a lack of angiogenesis that can complicate limb amputation. The foot, because of its architecture, becomes the part most prone to complications and the infection rate is higher mainly between the toes due to the humid nature. Therefore, the infection rate is significantly higher. Wound healing in diabetes is a dynamic process usually delayed due to poor immune function. Diabetes-related pedal neuropathy and perfusion disturbances can lead to a loss of sensation in the foot. This neuropathy can further be a risk factor for ulcer development due to repetitive mechanical stress that later might get infected by the invasion of microorganisms extending to the bone and causing an infection called pedal osteomyelitis. This review details the pathophysiology, the biomaterials aiding in the infection cure and regeneration of bone along with their limitations, as well as their future prospects.

Bioactive glass, a new tool for the treatment in the diabetic foot recalcitrant osteomyelitis: A case series with 24-month follow-up

BACKGROUND

The bioactive glass (BAG) is a promising solution for the reconstruction of bone defects and the eradication of infection in patients with osteomyelitis, however references to the treatment of diabetic foot osteomyelitis are scarce in the literature.

METHODS

Our experience in patients with diabetic foot osteomyelitis, who required surgical debridement and void filling, in which we use bioactive glass (n = 6), was evaluated. During a minimum follow-up of 24 months, the presence of persistent infection and healing rate, post-surgical complications, surgical reinterventions, degree of osseointegration and BAG-related side effects was analyzed.

RESULTS

At the end of the follow-up, none of the patients showed signs of persistent infection and the healing rate was 66.6% (4/6). Postoperative complications were noted in 3 patients and two of the them required new surgical intervention, both due to skin coverage or vascular complications. A complete osseointegration in the 66.6% of the patients and no cases of local adverse effects were recorded.

CONCLUSIONS

The bioactive glass can be a useful tool in the treatment of certain cases of diabetic foot osteomyelitis, provided that a multidisciplinary approach and strict patient selection is in place.

LEVEL OF EVIDENCE

IV.

Possible Advantages of S53P4 Bioactive Glass in the Treatment of Septic Osteoarthritis of the First Metatarsophalangeal Joint in the Diabetic Foot

Biomechanically, the great toe with its metatarsophalangeal (MTP) joint plays a key role in standing and walking, making the first MTP joint one of the main predilection sites for ulcer formation, and consequently for bone and joint infection and even amputation. If conservative treatment fails, the main goal of surgery is to remove all infected tissue and preserve the first ray. To improve surgical outcomes, development of new biomaterials like Bioactive Glass S53P4 has begun. Bioactive Glass is useful because of its antibacterial properties; furthermore, its osteostimulative and osteoconductive qualities make the bone substitute particularly suitable as a bone defect filler for the treatment of osteomyelitis. The aim of our retrospective observational study was to compare the outcomes following ulcerectomy with segmental resection of the infected joint and bone and temporary stabilization with an external fixator, both with and without added Bioactive Glass. A comparison of added Bioactive Glass with the traditional surgical treatment in septic osteoarthritis of the first MTP joint showed Bioactive Glass to be effective. During a one-year follow-up, patients with Bioactive Glass required no additional antibiotic therapy or surgical intervention. Bioactive Glass, when applied to the diabetic foot, showed itself to be a safe bone substitute biomaterial.