A review 1 of the clinical literature regarding lumbar disc herniation (LDH), particularly as it relates to the phenomenon known as “spontaneous LDH regression,” in which the herniation reduces or resolves without surgical treatment, concludes that the inflammatory response that contributes to nerve pain and damage may also be responsible for the spontaneous re-absorption of the herniation. Therefore, except in extreme cases where a neurological deficit or intolerable pain is experienced by the LBP patient, treatment for LDH should be conservative and custom-tailored to address the specific biochemical mechanisms at play in the patient.
What’s at Stake?
The pain and economic disability caused by LDH affects roughly 9 percent of the world’s population and is strongly associated with the aging process. Recent studies have indicated that the malady is more often caused by a failure in the endplate junction, rather than an annulus fibrosis (AF) failure, with its associated nerve ingrowth. This explains why up to 40 percent of patients diagnosed with LHD after imaging tests are asymptomatic.
Typically, LDH and degenerative disc treatments may be surgical, or conservative (non-surgical), with the decision about which approach is appropriate determined cooperatively by the clinician and patient. Because disc herniations often regress spontaneously, without surgical intervention, the authors of this review emphasize the need for clinicians to better understand the biomechanisms at work in LDH in order to make better-informed decisions about which treatment approach might be best for their patients.
Subtypes of LDH that More Frequently Regress
Magnetic Resonance Imaging (MRI) and CT Scan evidence of LDH regression indicate that particular subsets of herniations are more likely to spontaneously regress than others. Specifically, large-sized and sequestered herniations at the L4-L5 spinal segment level are more apt to partially or completely regress than other types of herniations. It is thought the regression is facilitated by the herniation’s exposure to the epidural vascular supply when the posterior longitudinal ligament ruptures. In fact, MRI studies have shown that the spontaneous regression of herniated disc materials is associated less with the size of the rupture and more with the vessels extending beyond the ligaments and supplying blood and nutrients to the inflamed herniation.
Of 36 analyzed herniations imaged in one study, 25 of them resolved spontaneously—17 percent subligamentous, 48 percent transligamentous, and a whopping 82 percent of sequestered herniations, respectively. This suggests the size of the hernia is less of a factor than the PLL rupture. In another study, all sequestered discs self-resolved within 9 months, while extruded discs took a full 12 months to resolve. Disc protrusions did not resolve, even after a full year.
Clinicians should pay particular attention to the subset type of LDH in their patients when deciding whether to treat their condition surgically or conservatively. Further study into the biochemical mechanisms involved in LDH and its potential for self-resolution would be beneficial in long-term LDH patient outcomes and should be a focus of research for clinicians treating patients with LDH.