Osteomyelitis in the Nonunion of a Patellar Fracture.

Osteomyelitis is by definition any infection of the bone. It can have a hematogenous or non-hematogenous mechanism of infection, but comorbidities such as cardiovascular disease, diabetes mellitus, and the presence of orthopedic hardware can increase the risk of osteomyelitis. Our case focuses on a 64-year-old Caucasian female with multiple comorbidities who presented with a fractured right patella that was not healing four months after the occurrence of the fracture. The patient reported cramping, fasciculations, and severe pain that was worsening. She also reported that she received nine X-rays from different orthopedists before receiving an MRI, ordered by internal medicine. The MRI showed a small knee effusion with mild generalized edema of the nearby subcutaneous tissues and evidence of nonunion of the fracture as evidenced by fracture fragments of the right patella. The MRI additionally showed increased signal in the bone fragments of the right patella, as well as the anterior and posterior superior rims of the right tibial plateau, concerning for potential osteomyelitis. Referral to infectious disease confirmed the diagnosis of patellar osteomyelitis, a rather rare diagnosis. The patient was promptly started on cefdinir and doxycycline, and within days of starting antibiotic therapy, her right knee pain was reduced to zero. Surgical debridement was not necessary, and the patient was able to resume her daily activities with the pain resolved. The possibility of patients only having to undergo antibiotic treatment for patellar osteomyelitis improves their chances of a full recovery and reduces the risks associated with undergoing surgical debridement.