Dolor lumbar persistente en pacientes con hernia de disco sintomática tratada mediante microdiscectomíafactores de riesgo y propuesta de índice pronóstico

Abstract

Introduction. Lumbar disc herniation (LDH) refers to the rupture of the intervertebral disc into the spinal canal compressing one or more nerve roots. This produces a clinical syndrome characterized by radicular and lumbar pain and, sometimes, neurological deficit. The Initial treatment of choice is medical, with anti-inflammatory drugs, physical therapy and postural control. Surgery is recommended when symptoms persist more than 4-6 weeks or if a neurological deficit is present. LDH surgery consists of resecting the herniated fragment with microsurgical techniques using minimal invasive approach to the spine, which is called microdiscectomy. This technique is highly effective in resolving pain and early restoring the normal work and physical activity. However, some patients complain of persistent lumbar pain (PLP) after surgery due to progressive degeneration of the operated intervertebral disc. This is a recognized complication in clinical practice but there are few studies about PLP and there is no consensus about its definition and its management. Objectives. The aim of this study was to clarify the PLP definition, to know its prevalence and associated risk factors. Proposing a prognostic index for PLP was another objective of this study. Recurrent disc herniation prevalence, risk factors and its association with PLP was also analyzed. Finally, we described the facet subluxation and its association with PLP. Methods. Retrospective study that included patients who were operated by microdiscectomy for lumbar disc herniation (LDH) in our department in the period from 2015 to 2019. We divided the enrolled patients into a PLP group and a non-PLP group, and compared some clinical, radiological and anatomical variables. We analyzed the relationship between PLP and the following variables: age, sex, disc herniation level, disc herniation recurrence, body mass index (BMI), Modic changes, facet subluxation, preoperative lumbar pain and lumbosacral transitional vertebrae (LSTV). Risk factors for recurrent disc herniation was analyzed with the same methodology. Results. Among 332 eligible patients, PLP was diagnosed in 99 (29.8%) patients. L5-S1 disc herniation level, recurrent disc herniation, obesity, Modic changes, and facet subluxation was independent risk factors for PLP after using multiple logistic regression analysis. We proposed a prognostic index for PLP based on these risk factors. The prognostic index classified the study participants into two groups: high and low risk of PLP after microdiscectomy. High risk patients according to the prognostic index had significant higher risk for PLP compared to patients with low risk. Women and patients under 50 years had an increased risk of suffering PLP but this did not reach statistical significance. Recurrent disc herniation was diagnosed in 60 (18.1%) patients. We found that obesity was significantly associated with recurrent disc herniation. Conclusions. PLP after microdiscectomy is a frequent and understudied condition. We found that L5-S1 disc herniation level, recurrent disc herniation, obesity, Modic changes, and facet subluxation were risk factors for PLP. Obesity was a risk factor for recurrent disc herniation, a frequent complication after microdiscectomy. These results can help us to improve the knowledge about lumbar microdiscectomy outcomes.