[Perforator-based keystone flap in the reconstruction of extensive tissue defects after lumbosacral spondylodesis]

Prolonged surgical site infections after spinal fusion surgery may lead to exposure of the implant due to the formation of extensive tissue defects and endanger the clinical outcome.

This study aims to enlighten the role of the keystone perforator flap method in the reconstruction of lumbar soft tissue defects.

The retrospective study included 11 consecutive patients with a wound dehiscence of over 6 × 6 cm defect area persisting for 2 weeks after spinal fusion. The keystone perforator flap was applied for the reconstruction of tissue defects, whereas the arterial blood supply of the flaps was based on the intramuscular and intermuscular perforating branches of the dorsal branches of the lumbar arteries.

The median age of our cohort was 58 years. The median body mass index (BMI) and Charlson comorbidity index (CCI) were 29.9 and 3.4, respectively. In eight cases a lumbosacral was carried out whereas in the remaining series a lumbar fusion was performed. In the course of the subsequent wound revision, on average 4 applications of negative pressure wound therapy (NPWT) were performed. The average defect size was 7.5 cm in width and 16.5 cm in length. The microbiological analysis of the tissue samples obtained intraoperatively after repeated NPWT revealed positive evidence of pathogenic bacteria in all cases. The average duration of inpatient treatment after flap surgery was 15 days, which was significantly shorter than the NPWT management of the open defect wounds (15.5 ± 2.5 vs. 37 ± 16.5, p < 0.05).

The keystone perforator flap offers a stable coverage for soft tissue defects and supports infection control after spinal fusion.