Although the diagnosis and treatment of osteomyelitis has improved, it remains a significant challenge to physicians. Management of osteomyelitis involves using antibiotic, radical debridement, and reconstruction with well-vascularized tissue. Several studies reported the efficacy of using free tissue transfer in treatment of chronic osteomyelitis. [5–10] Free flaps regardless of the composition provide reliable tissues not only to cover large defects but also to obliterate dead space, without further compromising local tissue. [2, 11] In this study, the authors aimed to evaluate the influence of co-morbidities and other factors such as diabetic foot ulcers, flap types, using antibiotic-beads and NPWT on the outcome of osteomyelitis treated with free flaps. The only factor that had a significant correlation with recurrence rate was ESRD. Patients with ESRD had 16.5 times higher odds of OM recurrence (p = 0.011). Renal failure has been known to impair wound healing in several ways. [12, 13] Additionally, it has been considered as a risk factor for free flap failure and limb amputation. [14–16] Therefore, caution must be taken when treating OM in patients with ESRD and free flaps should be carefully monitored post-operation.
PAOD is closely related to diabetes and smoking. Atherosclerotic changes decrease blood supply to the distal parts of the extremities. Consequently, it compromises the wound healing process and increases the rate of flap failure. Lee et al. reported a high rate of flap loss when they performed a combination of revascularization and free flap for severe PAOD patients. [16] Similarly, Oh et al. reported 10.212 times higher odds of flap failure in PAOD patients. [17] Nevertheless, our previous study showed the safe utilization of free flaps in PAOD patients following a successful angioplasty, particularly in cases where angioplasty achieved the complete revascularization of the pedal arch. [18] Similarly, in this study, all 21 patients with severely stenotic arteries underwent angioplasty before flap surgery, and complete flap necrosis was only seen in two cases. We believe that maximizing the blood flow by arterial intervention played a critical role in the reconstruction of ischemic wounds of the lower extremities.
Osteomyelitis following diabetic foot ulcers is a critical condition associated with complications and a high rate of lower limb amputation. [19] Choosing conservative or surgical treatment for diabetic foot osteomyelitis has been debated for years; however, the management of diabetic foot osteomyelitis still varies from center to center. [1, 20–22] In our institute, we believe that the combination of surgical and medical treatment would provide the better result. Although radical debridement often results in a large defect, this defect is frequently able to obliterate by the free flap transfer. With this in mind, the surgeon can completely resect the infected and unviable tissue including skin, soft tissue and bone without any hesitation. The result of our study showed no statistically significant difference of the outcomes between the group with diabetic foot ulcer and those with non-diabetic foot ulcer. Other studies also revealed similar results with a relatively high rate of limb salvage, which was very encouraging for the treatment of osteomyelitis secondary to a diabetic foot. [17, 23]
Besides the typical treatment modalities, adjuvant therapies including antibiotic-beads and NPWT have been proven effective in the management of OM. [24–26] Data analysis revealed that there were a tendency of reduced recurrence in patients who used antibiotic beads and NPWT. However, it was not statistically significant.
This study has several limitations since it was a single-center, retrospective, non-randomized study with a small sample size. Additionally, the small number of patients who underwent major amputation (two patients) were the reason we could not perform statistical analysis in this group. However, it revealed a high rate of limb salvage (96.9 percent) comparable to other studies. The relatively short duration of follow-up was the other limitation, as osteomyelitis can recur several years after treatment. Hence, further investigation should be continued in these patients. Despite these limitations, we believe that this study showed the efficacy of free flaps in the treatment of osteomyelitis and limb salvage even in patients with co-morbidities.