Radiofrequency-assisted Lumbar Semi-endoscopic Manual Discectomy using the Disc-FX System – Preliminary Results of Various Ongoing Clinical Outcome Studies Worldwide

Ever since Mixter and Barr ¹ reported an open surgical treatment for rupture of the intervertebral disc in 1934, numerous procedures have been performed. ^2–5 Low back pain is considered one of the most widely experienced health problems in the US and the world, affecting on average 85 % of the population at some point in their lives.6 It is the second most frequent condition, after the common cold, for which people see a physician or lose days from work. ⁷ Billions of dollars in medical expenditures and lost labour costs for this condition are incurred each year. ^8–10 Rates of spinal surgery in the US have increased sharply over time. ¹¹

Most of the time, low back pain improves with simple treatments, such as anti-inflammatories and painkillers. ^12–14 However, frequent refractory cases are treated with high-cost surgical procedures and have a long recovery period. ^{11, 15,16}

The preferred treatment for intractable discogenic low back pain and sciatica remains controversial. ^17–19 The medical literature contains many studies that demonstrate the efficacy of physical therapy, ²⁰ chiropractic, ²¹ steroid injections (epidural, facet), ²² percutaneous discectomy,²³ open discectomy ²⁴ and fusion and total disc replacement. ²⁵ In recent years, new minimally invasive endoscopic techniques have been developed by Yeung and Yeung. ^26–30 Disc pathology at the extremes of the spectrum have fairly well-accepted surgical indications. Large disc extrusions with severe nerve and/or cauda equina compression and associated neurological deficits are best treated with traditional surgical decompression and disc-fragment removal (laminectomy, laminotomy). Severe disc space collapse with end-stage discogenic changes in the vertebral endplates ± associated instability are best treated with disc fusion and/or replacement. ³¹

In this paper, we describe a radiofrequency-assisted lumbar semi-endoscopic manual discectomy (Disc-FX® system, elliquence, LLC) as an effective tool to treat acute and subacute disc injuries that involve focal contained disc herniations and/or annular tears with minimal degenerative changes (preserved disc height).

Pathoaetiology of a Degenerate Disc
Degenerative changes to the intervertebral discs can, under certain conditions, lead to pain in the area of the lumbar vertebrae with mono- or polysegmental radicular emanation. Likewise, there may be neurological deficiencies, such as transcribed sensory disturbances or weakness in the reference muscles. The intervertebral discs can also cause pain in the corresponding lumbar level by pressing nociceptive nerves and vegetative supply vessels that develop in the inflamed area.

Most of the pain is derived from the sinuvertebral nerve from the intervertebral discs as well as from tissue surrounding the nerves. This often makes it difficult to differentiate between radicular and pseudoradicular symptoms. The pathoaetiology of pain syndromes related to intervertebral discs has not been identified clearly. In addition to mechanical compression, which can often be demonstrated with imaging, vascular and biochemical changes in the segment should be considered along with innervation of the
annular tears.^32–37

In particular, venous stasis in the early phase of the pain syndrome appears to play a large role. The smallest changes in the epidural area can cause clear changes to the venous flow conditions and thereby influence the disease. Compressive processes in the lumbar spinal canal lead to secondary changes, such as impaired capillary blood flow, venous stasis and oedema, which can be demonstrated by magnetic resonance imaging (MRI). ³⁸

The decision to operate should be based primarily on the detailed anamnesis and clinical symptoms. There is extensive documentation of intervertebral-related symptoms that serves as the basis on which to assess the imaging of the morphological conditions. MRI of the spinal column is used as the standard. In exceptional cases, a computer programme can also deliver the desired information. When assessing the imaging, it is important for there to be a correspondence with the clinical mapping.