
12/03/2024
L-S: Incidence of and risk factors for lumbar disc herniation with radiculopathy in adults: A Systematic Review
Analysis by Physio Meets Science
👉 “Radiculopathy due to lumbar disc herniation (LDH) is one of the most recognizable disorders of the low back. The diagnosis is typically based on a combination of symptoms and signs suggesting lumbar spinal nerve root compression or irritation, such as radicular pain with nerve root tension signs, neurologic deficits, and imaging findings that correlate with the clinical syndrome (https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD007431.pub2/full, https://pubmed.ncbi.nlm.nih.gov/24239490/).
👉 LDH, defined as the localised displacement of disc material beyond the margins of the intervertebral disc space (s. figure below, https://pubmed.ncbi.nlm.nih.gov/24768732/), is the most common cause of lumbosacral radiculopathy (https://www.ncbi.nlm.nih.gov/books/NBK430837/). Compared with nonspecific low back pain without radiculopathy, LDH with radiculopathy is typically associated with greater pain, disability, healthcare use, and intervention (https://pubmed.ncbi.nlm.nih.gov/9516703/, https://pubmed.ncbi.nlm.nih.gov/15125627/, https://pubmed.ncbi.nlm.nih.gov/21358478/, https://pubmed.ncbi.nlm.nih.gov/31296665/).
📘 However, little is known about the incidence of LDH with radiculopathy, and consequently, risk factors are not well understood. The aim of a brand-new Systematic Review by Hincapié and colleagues was to synthesise the evidence on the incidence of and risk factors for LDH with radiculopathy in adults. (https://pubmed.ncbi.nlm.nih.gov/39453541/)
🔍 Methods
A systematic search of five electronic databases was conducted, covering research published from 1970 to September 2023. The databases included Medline, Embase, Cochrane Central Trials Registry, among others. The researchers focused on cohort and case-control studies while excluding cross-sectional, cadaveric, and animal studies. A total of 87 studies were critically reviewed, with 59 studies (68%) assessed as having low to moderate risk of bias, and thus included in the best evidence synthesis.
📊 Results
👉 Incidence of LDH with Radiculopathy
The incidence rates varied significantly depending on the population and case definitions used:
▶︎ For surgical cases, the annual incidence ranged from 0.3 to 2.7 per 1,000 persons.
▶︎ For hospital-based cases, the incidence was between 0.04 to 1.5 per 1,000 persons.
▶︎ For clinical cases (based on symptoms without surgery), estimates varied widely, from 0.1 to 298.3 per 1,000 persons. The variability in incidence rates was due to differences in diagnostic criteria, population characteristics, and settings (e.g., general, occupational, or healthcare-specific populations).
👉 Risk Factors for LDH with Radiculopathy:
👩🦳 Age: Middle-aged adults (30-50 years) showed a higher incidence compared to younger adults: Risk ratio 1.3 (1.2–1.5) to 1.8 (1.5–2.0).
👉 Behavioral and Lifestyle Factors:
🚬 Smoking increased the risk, especially in women, with a risk ratio of 1.4.
⚖️ Higher Body Mass Index (BMI) and other 🫀 cardiovascular risk factors were linked to a higher likelihood of developing LDH in women with associations ranging from 1.1 (1.0–1.3) to 1.5 (1.2–2.0)
👉 Occupational Factors:
🛠️ Jobs involving heavy lifting, repetitive forward bending, or prolonged sitting significantly contributed to the risk with associations ranging from 1.6 (1.1–2.7) to 3.7 (2.3–6.0).
🪚 Manual material handling and physically demanding work environments were particularly high-risk.
👉 Other Factors:
🤯 Mental stress and number of psychological distress symptoms were associated with LDH with radiculopathy in exploratory phase II studies (compared with none), with associations ranging from 1.6 to 3.0 (0.9–5.9).
💡 Conclusion:
The annual incidence of LDH with radiculopathy varies widely, reflecting the variability in evidence due to differences in case definitions and study populations. From phase III and low risk of bias studies, key risk factors have been identified. These include occupational physical factors, particularly cumulative lumbar load from activities like forward bending and manual materials handling, which show a strong association with LDH. Lifestyle factors such as smoking and high BMI are also contributors. Additionally, mental stress has been highlighted as a potential risk factor.
📷 Figure: CT and MRI Terminology for Herniated Disks. Panel A shows a normal lumbar intervertebral disk. Panel B shows a bulging disk. The dashed line indicates the normal disk space. Annular tissue extends beyond the normal disk space. Panel C shows protrusion of a disk. The greatest measure of the displaced material is less than the measure of the base of the displaced material. Panel D shows extrusion of a herni-ated disk. The greatest measure of the displaced disk material is greater than the measure of the base of the displaced disk material. Panel E shows sequestration of a herniated disk. The displaced disk material has lost all connection with the disk of origin.” (https://pubmed.ncbi.nlm.nih.gov/27144851/)
- Physio Meets Science