gms | German Medical Science

Objective: To evaluate the influence of fat distribution, measured from preoperative images, for surgical wound infections after dorsal lumbar spine surgery.

Method: 663 consecutive patients (54 % male, 46 % female) who underwent lumbar spine surgery in a five year period were identified and retrospectively analysed. The abdominal a.p. diameter on the pathological level (skin to skin), the maximum abdominal a.p. diameter (skin to skin), the thickness of the subcutaneous fat tissue, the diameter of the autochthonous muscles and the distance from lamina to skin were determined by an integrated analysis tool on preoperative scans (MRI, CT). Furthermore, the body mass index (BMI) was calculated. The relevance of these parameters for postoperative infections was analysed.

Results: 30 of 663 patients (4.5%) developed a surgical site infection. Within this patient group the BMI was significant higher (31.0, SD±5.7 compared to 28.38, SD±5.6, p<0.01). Corresponding results could be observed for the abdominal a.p. diameter on the pathological level (294mm, SD±39.7 vs. 270mm, SD±48.3, p<0.039). No statistical difference was found for the thickness of subcutaneous fat tissue (27.9mm, SD±20.4 vs. 23.5mm, SD±13.3), the muscle size (38.7mm, SD±9.0 vs. 39.8mm, SD±11.9), the maximum a.p. diameter (307.2mm, SD±37.9 vs. 291mm, SD±47.5) or the lamina to skin distance (69.7mm, SD±20.4 vs. 64.7mm, SD±31.9).

Conclusions: BMI and the abdominal a.p. diameter on the pathological level, but none of the other analysed items of differential fat distribution correlated with the risk of postoperative surgical site infection. Both parameters may be used for risk analysis and patient counselling.