Navigating diagnostic challenges:

Background: Escherichia coli ( Case Description: A 54-year-old man who underwent lumbar spinal fusion surgery. Initially treated for delayed onset postsurgical spondylodiscitis, the diagnosis of rhBMP-2 induced vertebral endplate osteolysis was only established after clinical and radiological reassessment. The patient presented with non-specific lower back pain 3 months after surgery. Initial magnetic resonance imaging (MRI) revealed single-level intradiscal fluid with adjacent endplate erosions, mild disc cage subsidence, marrow edema, and a rim-enhancing fluid collection. Biochemical markers were not convincing for spondylodiscitis and blood cultures were negative. Nonetheless, he was treated empirically with oral antibiotics. The patient showed significant improvement 3 weeks after the initial diagnosis was made, with subsequent imaging findings demonstrating the development of endplate osteolysis and implant subsidence. Conclusions: This case demonstrates the difficulty in diagnosing rhBMP-2 induced endplate osteolysis as it mimics spondylodiscitis on imaging. Clinicians should consider this complication as a differential diagnosis to avoid unnecessary antibiotic treatment and to improve postoperative monitoring protocols, even with newer rhBMP-2 formulations.