Fig. 3

Representative histological sections in patients with PVM degeneration. A female patient aged 66 years old (A): Adipocytes infiltration of multifidus muscle, the red arrow indicates adipocytes. A male patient aged 25 years old (B): Inflammatory cells infiltration of multifidus muscle without adipocytes, black arrow indicates inflammatory cells (mainly neutrophils). A male patient aged 43 years old (C): Adipocytes and inflammatory cells infiltration, red and black arrows indicate adipocytes and inflammatory cells (mainly lymphocytes), respectively. (scale bar =100 μm)