Treating Iatrogenic Calcaneal Osteomyelitis Following A Plantar Heel Injection
Upon removal of the cast, a hemorrhagic bulla was encompassing the entire heel (see figure 3). Compression of the lesion resulted in the expression of purulent drainage. No crepitus was present within the soft tissue. The patient complained of chills and was tachycardic, but she was afebrile and normotensive. The patient was admitted to the hospital for empiric antibiotic therapy.
We performed the first of four excisional debridements in the operating room setting (see figure 4). We also obtained a biopsy and culture of the calcaneus. Following the first operation, a repeat MRI revealed a mottled T1 signal intensity suggestive of osteomyelitis of the calcaneus (see figure 5). Bone cultures of the calcaneus revealed infection with methicillin-resistant Staphylococcus aureus (MRSA) and a bone biopsy showed fibrotic and chronic inflammation consistent with osteomyelitis.
The young patient was not amenable to total or subtotal calcanectomy. We formulated a course of long-term antibiotic therapy in conjunction with the infectious disease service. We employed weekly sharp debridements, negative pressure wound dressing and hyperbaric oxygen therapy (HBOT).
Three months after the first admission, the patient was hospitalized for a Clostridium difficile infection secondary to chronic antibiosis. Ten months after her initial presentation, the patient was admitted for a third time with a diagnosis of cellulitis, which emanated from an open wound at the plantar heel that was 1 cm in circumference (see figure 6). One year after her initial presentation, the patient was admitted a fourth time due to cellulitis and abscess formation.
The patient went to the operating room where we excised the wound and sinus tract, and performed a calcaneal debridement. We took multiple cores from the calcaneus via trephination and packed the deficits with OsteoSet (Wright Medical) calcium sulfate beads impregnated with vancomycin (see figure 7). The original bone culture organisms were sensitive to vancomycin and the use of calcium sulfate beads obviated the need for removal. Upon discharge, we followed the patient closely as an outpatient and placed her on eight weeks of intravenous cefazolin (Ancef, Sagent Pharmaceuticals) therapy.
Nine weeks after the debridement of the calcaneus and implantation of the antibiotic-laden beads, a small hyperkeratotic lesion arose on the plantar foot, which we debrided (see figure 8). No local signs of infection were present. The patient did complain of pain to the lateral calcaneus, which we attributed to the alteration of her gait due to the presence of the wound. The infectious disease service discontinued intravenous antibiotics and prescribed oral cephalexin as suppressive therapy for a duration of five years. Refer to the table “Insights On The Treatment Of The Patient” at left for a concise summary of the patient’s course of treatment.