Guan F, et al. – This retrospective study aimed to elucidate the risk factors of postoperative low back pain (LBP) for low–grade degenerative spondylolisthesis. Risk factors for the postoperative LBP were lumbar multifidus (LM) intramuscular adipose tissue (IMAT) and symptom duration. Before the operation, patients with severe LM IMAT reported more severe LBP. In patients with shorter symptom duration, postoperative LBP disappeared more often.

• The physicians included 239 patients who underwent posterior lumbar fusion between January 2011 and January 2015 in this analysis.
• Patient characteristics, surgical characteristics, and radiographic characteristics were investigated.

• After the operation, the mean visual analogue scale (VAS) score of LBP decreased dramatically.
• In patients with severe LM IMAT, the mean preoperative VAS score was greater.
• Among patients with shorter symptom duration, the postoperative VAS score was dramatically lower.
• In patients with shorter symptom duration, postoperative LBP disappeared more often.
• LBP VAS changing demonstrated significant differences in different symptom duration groups and LM IMAT groups.