01 · The Patient
A 70-year-old man in a state of extreme systemic frailty came to our attention after developing a surgical site infection following amputation of the left big toe and subsequent transmetatarsal surgery.
The patient had a long history of diabetic foot disease. He had been diabetic for approximately twenty years and suffered from chronic non-revascularizable peripheral arterial disease, diabetic chronic renal failure and neuropathy. His cardiovascular history was also severe: in 2003 he underwent placement of a drug-eluting coronary stent for ischemic coronary artery disease, and in 2022 he was admitted for acute myocardial infarction, treated with coronary stenting. He had also undergone right carotid endarterectomy.
The patient had previously undergone amputation of the left big toe in 2010 due to bone exposure and had been known to our center since 2017 for recurrent lesions on a mixed diabetic foot.
Pharmacological therapy included pantoprazole, rivaroxaban, aspirin, bisoprolol, rosuvastatin-ezetimibe, dutasteride, silodosin, pioglitazone, Suliqua and metformin.
02 · The Wound
The patient returned to our care in October 2025 after hospitalization at another center for osteomyelitis and septic condition, which had required transmetatarsal amputation of the fourth and fifth metatarsals of the left foot.
At presentation on October 4, 2025, the wound showed dehiscence with sutures still in place. The lesion measured 1.62 cm² and showed signs of local infection, with exposure of the bone stump at the proximal end of the wound.
Pain could not be reliably assessed because of pre-existing diabetic neuropathy. Standard assessment using oximetry and hyperspectral imaging was also not feasible because the inflammatory-infectious state would have compromised test reliability.
The clinical risk was high: in the context of diabetic neuropathy, chronic non-revascularizable PAD, renal impairment and exposed bone, the wound carried a concrete risk of progression toward major amputation.
03 · Prior treatment history
The patient had been known to our center for several years because of recurrent diabetic foot complications.
Between 2017 and 2024, four lesions had developed on a mixed diabetic foot characterized by both vasculopathy and neuropathy. He had also undergone resection of the first phalanx of the right big toe. These events were associated with persistent use of unsuitable footwear and poor adherence to dietary guidelines, resulting in poor glycemic control.
In October 2025, after the recent septic episode and transmetatarsal amputation, the patient was offered a mid-thigh amputation elsewhere, but refused it and sought our opinion.
At our center, antibiotic therapy was maintained based on intraoperative bone culture results. Sutures were removed and an initial debridement was performed. The patient confirmed his determination not to accept amputation, and the risks were clearly explained.
04 · Decision and protocol
Given the high risk of amputation and the patient’s refusal of a destructive surgical option, a conservative limb-salvage strategy was proposed.
The treatment plan included surgical revision, removal of compromised tissue, local infection control, off-loading and mononuclear cell therapy.
Three applications of mononuclear cells were scheduled, spaced approximately 30 to 40 days apart. Each session combined infiltrative E-PRP with CGF coverage.
Hyperbaric oxygen therapy was also considered, but it was later ruled out because the patient was claustrophobic.
The regenerative procedure was performed using the High Q Cell® All-In-One procedural kit. E-PRP was infiltrated along the angiosome line of the anterior tibial and peroneal arteries, while CGF was applied to cover the lesion.
05 · Clinical response
On October 13, 2025, the patient was admitted for wound revision, resection of the clinically compromised fifth metatarsal and application of negative pressure wound therapy for five days.
During the same treatment phase, infiltrative E-PRP was administered along the anterior tibial and peroneal arterial lines, and the wound was covered with CGF. The postoperative course was uneventful.
The patient tolerated off-loading with a pneumatic compression system and walker. After the perioperative phase, local treatment with silver-based antiseptics was continued.
On November 27, 2025, the second E-PRP and CGF procedure was performed in a day hospital setting. At that point, the wound measured 4.53 cm². The same approach was used: E-PRP infiltration along the anterotibial and peroneal arterial lines, combined with CGF coverage.
The postoperative course remained uneventful, and the lesion progressively improved. Glycemic and renal control parameters also improved, and hydrofiber dressings were introduced to promote granulation.
06 · Outcome and follow-up
On December 18, 2025, the lesion had already reduced significantly to 0.73 cm², corresponding to a reduction of more than 83%.
In early January, after six weeks of therapy, antibiotic treatment was discontinued.
On January 16, 2026, the wound showed a substantially stable area of 0.86 cm². The third E-PRP and CGF graft was performed as planned, using the same procedural method and kit. Because a plantar lesion had appeared at the head of the second toe, that toe was removed at the same time. The postoperative course was uneventful, and the patient was discharged on the third day.
On February 26, 2026, after an uneventful period of local treatment with hydrofiber dressings, the case was considered resolved. The patient was discharged with a prescription for suitable custom-made footwear.
On April 13, 2026, six months after the first procedure, follow-up confirmed a stable final result with good scarring. :contentReference[oaicite:1]{index=1}
07 · Discussion
This case illustrates the potential role of combined E-PRP and CGF therapy as part of a controlled limb-salvage strategy in a fragile diabetic patient with surgical site infection and exposed bone.
The case was particularly complex because the wound developed after transmetatarsal amputation in a patient with neuropathy, chronic non-revascularizable PAD, renal impairment and severe cardiovascular disease. Standard therapeutic margins were narrow, and the risk of major amputation was high.
The treatment did not replace the gold standards of care. Surgical revision, removal of non-viable tissue, infection control, antibiotic therapy, off-loading and appropriate footwear remained essential elements of the protocol.
Within this structured approach, mononuclear cell therapy may have contributed to improving the local biological environment by supporting targeted vascular stimulation, tissue repair and local defense mechanisms.
The use of the woundosome concept was particularly relevant: E-PRP was infiltrated along the anterior tibial and peroneal arterial lines to concentrate regenerative factors in the vascular territory involved by the lesion.
The most meaningful result was not only wound closure, but the preservation of the limb in a patient who had already been considered at high risk for amputation. The case resolved within ten weeks, and the stable scar observed at six-month follow-up suggests a durable clinical response.