Long-term outcome after surgery and revision surgery for sciatica

Low back pain (LBP) is a major global health problem. While most cases of LBP are non-specific, this thesis focuses on low back pain with leg pain, commonly referred to as sciatica or lumbosacral radicular syndrome (LRS). Sciatica is characterised by spine-related radiating leg pain and can have a profound impact on patients’ physical, psychological, and social well-being. Diagnosis is primarily clinical and based on patient history, physical examination, and neurological assessment. In most cases, sciatica is caused by nerve root compression due to lumbar disc herniation, often accompanied by inflammatory processes. The prognosis of sciatica caused by disc herniation is generally favourable. Approximately 60% of patients recover within three months and about 70% within one year. Nevertheless, up to 30% of patients experience persistent symptoms beyond one year. Treatment options range from conservative approaches, such as physical therapy and pharmacological pain management, to more invasive interventions including epidural steroid injections and multidisciplinary rehabilitation programmes. Surgical treatment is considered when conservative measures fail to provide sufficient improvement, when symptoms severely affect quality of life, or when surgery aligns with the informed preference of the patient. This thesis focuses on open microdiscectomy, performed using loupe magnification and headlight assistance through a small skin incision. Although short-term surgical outcomes are generally good, a subset of patients develop recurrent sciatica due to disc re-herniation, sometimes requiring revision surgery. Therefore, this thesis evaluates long-term outcomes of both primary and revision surgery and identifies factors associated with unsatisfactory results. Chapter 2 presents the five-year follow-up results of the multicentre, prospective, randomised Sciatica Trial, which compared early surgery with prolonged conservative treatment followed by surgery if necessary in patients with 6–12 weeks of sciatica. Regardless of initial treatment strategy, 21% of patients reported unsatisfactory recovery at long-term follow-up. Additionally, 31% of patients experienced a change in outcome status over time. Predictors of an unfavourable outcome included age over 40 years, severe leg pain at baseline, and higher affective McGill pain scores. Chapter 3 contextualises these findings through a retrospective cohort study of patients treated with open microdiscectomy, with a follow-up of eight years. In this cohort, 34% of patients reported an unfavourable perceived recovery. Poor outcomes were associated with higher levels of leg and back pain and greater disability. Re-operation for recurrent sciatica was required in 26% of patients and was strongly associated with an increased risk of an unsatisfactory outcome. Patients who underwent only one surgical procedure had a 75% likelihood of good recovery, compared with 43% among those who required two or more operations. In Chapter 4, long-term outcomes of revision microdiscectomy were evaluated. After ten years of follow-up, 60% of patients reported an unfavourable outcome, and the risk of further revision surgery was substantial. Despite these disappointing results, and given the limited effectiveness of alternative treatment options, revision microdiscectomy remains a valid therapeutic option for recurrent lumbar sciatica. Chapter 5 explores posterior lumbar interbody fusion (PLIF) using stand-alone trabecular metal cages in patients with repeatedly recurrent disc herniation and associated low back pain. Although spinal fusion theoretically offers advantages by reducing segmental mobility and eliminating the intervertebral disc, only 46% of patients reported a good recovery. Given these suboptimal results, the indication for stand-alone PLIF has diminished. Finally, Chapter 6 critically examines the methodological choice of dichotomising Likert-scale satisfaction scores to define favourable and unfavourable outcomes. Different dichotomisation strategies resulted in large differences in reported success rates, raising questions about how patient satisfaction should be interpreted. The thesis concludes with a proposal for a large, multicentre, prospective cost-effectiveness study using standardised outcome measures to optimise long-term treatment strategies for patients with sciatica.