Nonrandomized cohort: microdiscectomy speeds relief in lumbar radiculopathy

Microdiscectomy provided faster relief than autologous conditioned serum in a 12-month exploratory cohort study of adults with degenerative lumbar disc disease and persistent radiculopathy, although the groups showed no significant differences in major patient-reported outcomes by the final assessment. The prospective study included 140 patients whose symptoms had not improved after at least six months of conservative treatment: 86 underwent surgery and 54 received injections of autologous conditioned serum, marketed as Orthokine. Both approaches were associated with large improvements in pain, disability, pain quality, physical and mental quality of life, life satisfaction, fatigue and sexual satisfaction that were sustained through one year. Because treatment was selected according to clinical findings and patient preference rather than randomized allocation, the results show an association rather than establishing that either treatment caused the observed outcomes.

The participants were 24 to 60 years old, with a mean age of 48.7 years, and 86 were men and 54 were women. All 140 completed clinical, questionnaire, blood and magnetic resonance imaging assessments before treatment and at three, six and 12 months. Most patients had moderate or severe radiculopathy, and baseline pain and disability were similar between the groups. Researchers measured pain with the Visual Analogue Scale and Numerical Rating Scale, disability with the Oswestry Disability Index and pain quality with the Short-Form McGill Pain Questionnaire. Broader assessments included the 36-item Short-Form Health Survey, the Satisfaction With Life Scale, the FACIT-Fatigue subscale and the 21-item Davies Sexual Satisfaction Scale. Serum C-reactive protein and MRI measures of canal occupancy, disc height, nerve-root compression and other structural features were also evaluated.

Treatment allocation followed shared decision-making after the treating physician reviewed each baseline MRI. Extrusions and sequestrations generally favored microdiscectomy because removal of the offending material could directly decompress a nerve root, whereas contained protrusions generally favored the injection approach. Patients and physicians also weighed invasiveness, expected recovery and personal preference. This created important baseline differences: surgery patients were older on average, at 50.4 years compared with 46.1 years, and were more likely to have extrusions or sequestrations. Protrusions made up 61.1% of the conditioned-serum group, compared with 24.4% of the surgery group. The researchers described this as confounding by indication, meaning that the treatment groups did not begin with fully comparable anatomical and clinical profiles. An additional analysis adjusted for baseline score, age and herniation type, but statistical adjustment could not eliminate unmeasured differences.

Microdiscectomy was performed under general anesthesia through a limited posterior mini-open approach using microscopic or loupe magnification. Surgeons removed the herniated or sequestered disc fragment to decompress the affected nerve root, preserving uninvolved disc structures where feasible. The conditioned-serum pathway required four image-guided periradicular epidural injections of 4 millilitres each, delivered at approximately seven-day intervals at the affected disc level and the level immediately below it. The serum was prepared from the patient’s own blood, incubated in glass tubes containing chromium-treated beads and then centrifuged. It is enriched with interleukin-1 receptor antagonist and other anti-inflammatory mediators. The study compared the treatments over one year, but it did not include a no-intervention control group that could distinguish treatment-specific changes from the natural history of contained herniations.

The clearest separation appeared at the three-month assessment. Mean visual analogue pain scores were 3.26 with microdiscectomy and 3.92 with conditioned serum, a statistically significant difference. Numerical pain scores and Oswestry Disability Index scores also favored surgery, with mean disability scores of 37.7% and 43.0%, respectively. Patients undergoing surgery reported better physical and mental quality-of-life scores and higher overall sexual-satisfaction scores at this point. At six months, pain intensity and pain quality remained significantly better in the surgery group, but differences in disability, physical or mental quality of life and overall sexual satisfaction were no longer statistically significant. By 12 months, none of those outcomes differed significantly between the groups. Adjusted analyses reproduced this sequence: pain and disability remained significantly better with surgery at three months, while adjusted differences were not significant at one year.

Across the full cohort, every major patient-reported outcome improved substantially with both treatments and remained improved through 12 months. The statistical analysis found a significant effect of time for pain, disability, pain quality, quality of life, life satisfaction, fatigue and sexual satisfaction, with large within-group effect sizes at one year. Life satisfaction and fatigue did not show a significant group-by-time interaction, indicating broadly parallel improvement in the two groups. Mean serum C-reactive protein concentrations also fell similarly: from 2.65 to 1.92 milligrams per litre with microdiscectomy and from 2.67 to 1.87 milligrams per litre with conditioned serum. The investigators cautioned that C-reactive protein is a nonspecific marker of systemic inflammation, not a direct measure of inflammation within the intervertebral disc or activity in the interleukin-1 pathway. The parallel decline therefore did not establish a treatment-specific anti-inflammatory effect.

MRI showed persistent structural differences between the groups. The percentage of the spinal canal occupied by tissue was lower after microdiscectomy at three, six and 12 months, consistent with the direct removal of disc material during surgery. Intervertebral disc height did not differ at baseline or at three months, but it was greater after conditioned serum at six months—8.39 millimetres versus 8.02 millimetres—and at 12 months. The group-by-time interaction for disc height had a partial eta-squared of 0.292, the largest interaction effect among the variables examined. This observation remains uncertain: a conventional morphometric measurement cannot show that the disc matrix regenerated or that the underlying degeneration changed. Reduced inflammation or altered mechanical loading could produce a similar change in measured height, and the investigators said dedicated imaging with compositional methods would be required to distinguish those possibilities. Nerve-root compression and high-intensity zones improved over time in both groups without sustained between-group differences.

The inclusion of fatigue, life satisfaction and a dedicated sexual-satisfaction instrument expanded the study beyond conventional pain and disability endpoints. Sexual-satisfaction scores rose from moderate levels at baseline to near-maximal values in both groups. Surgery led at three months, but the overall difference was no longer significant at 12 months. Exploratory subscale analysis showed a conditioned-serum advantage for the physical component at one year, a borderline emotional-component difference and no significant control-component difference. Sex-stratified results were also exploratory: improvement after microdiscectomy was similar for men and women, while the conditioned-serum analysis produced higher scores among men at 12 months. These smaller subgroup analyses, together with the broad battery of outcomes and multiple time points, were not adjusted for multiplicity and should be treated as hypothesis-generating rather than conclusive evidence of a treatment-specific difference.

Several limitations restrict how the findings can be generalized. Treatment was not randomized, groups differed in age and herniation morphology, and the conditioned-serum group was smaller, limiting statistical power for modest subgroup differences. Analgesic use and physiotherapy during follow-up were not systematically recorded, while follow-up MRI readers could not be fully blinded to treatment because postoperative changes could reveal allocation. The cohort was restricted to people classified as White or Caucasian, so applicability to other populations remains uncertain. Follow-up ended at 12 months and cannot establish longer-term durability or late recurrence. The one-year window also fell within the study’s exploratory design rather than a longer comparative-effectiveness assessment. The authors therefore said the results warrant confirmation in randomized trials with longer follow-up, blinded compositional imaging and the same multidimensional outcome battery, as well as a conservative-treatment arm that could help distinguish treatment effects from spontaneous changes in contained herniations.

Subject of Research: Comparative outcomes of microdiscectomy and autologous conditioned serum for persistent lumbar radiculopathy

Article Title: Microdiscectomy versus autologous conditioned serum for degenerative lumbar disc disease with radiculopathy: a 12–month exploratory study

Article References: Gogol, P., Wiśniewski, R., Pasztaleniec, R., Szczepaniak, R., Sobstyl, M., Staszkiewicz, R., Ratuski, P., & Grabarek, B. O. (2026). Microdiscectomy versus autologous conditioned serum for degenerative lumbar disc disease with radiculopathy: a 12–month exploratory study. Frontiers in Neurology, 17, Article 1972710. https://doi.org/10.3389/fneur.2026.1972710

Image Credits: AI Generated

DOI: 10.3389/fneur.2026.1972710

Keywords: microdiscectomy, autologous conditioned serum, lumbar radiculopathy, degenerative disc disease, cohort study, pain relief, quality of life, MRI, disc height, sexual satisfaction, versus, autologous