Degree of paraspinal muscle fat infiltration predicts non-infectious poor wound healing following lumbar surgery
BACKGROUND: Non-infectious poor wound healing following lumbar surgery is a significant clinical complication that prolongs hospitalization and increases the risk of reoperation. However, its predictive indicators remain unclear. Based on the hypothesis that paraspinal muscle degeneration may impede tissue repair by altering the local microenvironment, this study aimed to investigate the predictive value of preoperative paraspinal muscle fatty infiltration for non-infectious poor wound healing and its association with osteoporosis. OBJECTIVE: To quantify the degree of paraspinal muscle fatty infiltration using preoperative MRI and evaluate its predictive value for non-infectious poor wound healing after lumbar surgery. METHODS: A retrospective analysis was conducted on medical records of 4,368 patients who underwent traditional open posterior lumbar surgery at Third Affiliated Hospital of Guangzhou University of Chinese Medicine between 2019 and 2024. We screened 190 patients with a postoperative hospital stay of 15 days or longer. Based on postoperative wound healing and infection indicators, 41 patients with non-infectious poor healing were selected as the poor healing group. From the remaining 4,178 patients, 40 patients with good healing were selected as the good healing group. The poor healing group was further subdivided into osteoporosis and non-osteoporosis subgroups. Preoperative lumbar MRI images were collected, and Image J software was used to measure the cross-sectional area of the psoas major muscle and the percentage of fat infiltration in the erector spinae and multifidus muscles. RESULTS AND CONCLUSION: (1) There were no significant differences in gender, age, or diabetes between the poor healing and good healing groups (P > 0.05). (2) The functional cross-sectional area and fat infiltration percentage of the psoas major, erector spinae, and multifidus muscles were significantly different between the two groups (P < 0.05). (3) Logistic regression analysis showed that fat infiltration percentage was an independent risk factor for poor wound healing. (4) Receiver operating characteristic curve analysis showed that fat infiltration percentage had high predictive value for poor wound healing (area under the curve > 0.7). (5) One-way ANOVA indicated that osteoporosis was a risk factor for fat infiltration in the L4 multifidus muscle (P < 0.05). (6) The results indicate that paraspinal muscle fat infiltration percentage is an important predictor of non-infectious poor wound healing after traditional open posterior lumbar surgery, providing clinical reference. Osteoporosis was also confirmed as a risk factor for L4 multifidus fat infiltration, but due to the small subgroup sample size, whether osteoporosis affects non-infectious poor healing after lumbar surgery requires further clinical trials.