Adjacent intervertebral space infection after lumbar fusion.

BACKGROUND: Surgical site infection is a catastrophic complication after spinal surgery, which seriously affects the progress of rehabilitation and clinical outcome. Currently the clinical reports on spinal surgical site infections are mostly confined to the surgical segment itself and there are few reports on adjacent segment infections after spinal surgery. STUDY DESIGN: Case report. OBJECTIVE: To report a clinical case with adjacent level infection after spinal fusion. METHODS: We report the case of a 68-year-old woman who underwent posterior lumbar 4­5 laminectomy, posterolateral fusion and internal fixation. The patient showed signs of surgical site infection, such as surgical site pain, high fever and increase of the inflammatory index 1 week after the operation. Magnetic resonance imaging (MRI) confirmed the diagnosis of adjacent intervertebral disc infection. The patient received early combined, high-dose anti-infection treatment instead of debridement. RESULTS: After the conservative treatment, the infection was controlled and the patient subsequently enjoyed a normal daily life. CONCLUSION: Adjacent level infections can occur after spinal surgery. Early diagnosis and anti-infection treatment played an important role in the treatment of this kind of complication.

Biological evaluation of human degenerated nucleus pulposus cells in functionalized self-assembling peptide nanofiber hydrogel scaffold.

Nucleus pulposus (NP) tissue engineering has been proposed as a novel biological treatment for early-stage intervertebral disc degeneration. In this study, a novel functional self-assembling peptide PKP was first designed by linking the short functional motif of bone morphogenetic protein-7 (BMP7) to the C-terminal of RADA16-I, and another new functional self-assembling peptide was obtained by mixing RKP with RADA16-I. Then, the biocompatibilities and bioactivities of RKP and RAD-RKP for human degenerated nucleus pulposus cells (hNPCs) were studied in vitro. Atomic force microscopy and scanning electron microscopy (SEM) confirmed that both RKP and RAD-RKP could self-assemble into three-dimensional (3D) nanofiber hydrogel scaffolds in a culture medium at 37°C. After the hNPCs were cultured in 3D scaffolds, both RKP and RAD-RKP exhibited reliable attachment and extremely low cytotoxicities (<14%), which were verified by SEM and cytotoxity assays, respectively. Our results also showed that the functional-based scaffolds could increase the proliferation and migration of hNPCs after 7 days compared with culture plates and pure RADA16-I. Quantitative real-time polymerase chain reaction demonstrated that the expressions of collagen II α1, Sox-9, and aggrecan were upregulated, while collagen I α1 was downregulated by functional-based scaffolds after 28 days. Furthermore, we also confirmed that RAD-RKP exhibited a higher hNPC proliferation, migration, and expression of Sox-9 and aggrecan compared with pure RKP. Therefore, the results of this study indicated that the BMP7 short motif-designed functional self-assembling peptide nanofiber hydrogels could be used as excellent scaffolds in NP tissue engineering, and RAD-RKP might have further potential application in human mild degenerated NP tissue regeneration.