Background. Recently, some studies have focused attention on the possibility that anaerobic pathogens of low virulence could constitute an etiological factor in disc herniation. There have been isolated such strains, predominantly Propionibacterium acne, between 7 and 53% of patients undergoing surgery for disc pathology. According to these studies, patients with anaerobic infections of the disc are more likely to develop Modic changes in the adjacent vertebrae. The aim of this work was to test this hypothesis by growing in specific media the disc material extracted in a series of lumbar discectomy and relating this factor with the presence of pre-intervention Modic changes. Methods. A total of 22 consecutive patients undergoing primary unisegmental discectomy for lumbar disc herniation (77.2% male, mean age 40.1 ± 9.1 years) were included. All patients were immunocompetent and none had previously received an epidural steroid injection prior surgery. MRI study confirmed the disc herniation. Following strict antiseptic protocols, the extracted disc material was sent for slow-growth anaerobic enriched culture (>10 days). Results. In total, anaerobic cultures were positive in 7 cases (31.8%) all men. In 5 of these cases, the symptoms developed with an acute onset. The isolated germs were always unique: Propionibacterium acne (3), Streptococcus parasanguinis (1), Actinomyces naeslundii (1), Actinomyces meyeri (1) and methicillin sensitive Staphylococcus epidermidis. Only two (28.6%) of these 7 patients had Modic changes on MRI prior surgery (one type I, one type 2). None of the patients with negative cultures had Modic changes. Conclusions. These findings support the theory that anaerobic infections of low virulence and slow growth may contribute to the pathogenesis of herniated discs. However, these cases do not necessarily develop type 1 Modic changes as previously speculated. Level of evidence. Level IV

Lumbar disc herniation represents by far the most prevalent pathology, causing pain and sciatica and constitutes an important cause of disability and one of the most cost-intensive health problems. The aetiology is very complex. In recent years, it has been suggested in twin and family studies that genetic risk factors contribute to the development of LDH. Our purpose is to analyse genetic susceptibility to symptomatic LDH in Spanish surgical patients treated with different surgical techniques. Single-nucleotide polymorphisms (SNPs) in VDR, GDF5, Col1A1, THBS2 and CHST were genotyped in a case-control study with 50 symptomatic LDH in Spanish surgical patients and 50 Spanish health controls. All patients provided signed informed consent. Sampling was carried out with a puncture of the pad of a finger using a sterile, single-use lancet. SNPs were determined by real-time polymerase chain reaction (PCR) using specific, unique probes with the analysis of the melting temperature of hybrids. The X2 test compared genotypes between groups. Multivariate logistic regression analysed the significance of many covariates and the incidence of LDH. We found significant differences in age, gender and smoking status between the two groups. There were significant differences in the CC (rs2228570) genotype in VDR in patients with LDH (p<0.05). There were significant differences in the GT (rs1800012) genotype in Col1A1 in patients with LDH (p=0.001). In Col1A1, T allele was more frequent in the case group than in the control group (p<0.001). Regarding surgical techniques, of the 50 patients included in the cases group, 25 were treated with open microdiscectomy and 25 received endoscopic discectomy. Outcomes were assessed at 12 months using VAS, and NASS instrument. Postoperative pain and pain medication were significantly reduced in the endoscopic group. Patient satisfaction is greater in the endoscopic group, with shorter hospital stays and earlier return to normal activity. GT genotype in Col1A1 was more frecuent in the endoscopic group compared to the microdiscectomy group (p=0.002). CC genotype in VDR and GT genotype in Col1A1 are associated with symptomatic LDH susceptibility in Spanish surgical patients. GT genotype in Col1A1 is associated with symptomatic LDH treated with full-endoscopic discectomy

Objectives

Degenerative disc disease (DDD) and osteoarthritis (OA) are relatively frequent causes of disability amongst the elderly; they constitute serious socioeconomic costs and significantly impair quality of life. Previous studies to date have found that aggrecan variable number of tandem repeats (VNTR) contributes both to DDD and OA. However, current data are not consistent across studies. The purpose of this study was to evaluate systematically the relationship between aggrecan VNTR, and DDD and/or OA.