、。
She's been troubled by back pain for years.
Literal
She [topic-は] long-years, lower-back-pain [by-で] is-troubled.
腰痛 ('lower back pain') combines 腰 (lower back/waist) and 痛 (pain). で marks it as the cause of 困っている ('being troubled'). 長年 ('for many years') as a standalone adverb sets the duration. 困る expresses being at a loss or inconvenienced — not just pain, but the practical difficulty it causes.