Prevention of recurrent disc herniation after lumbar microdiscectomy and sequestrectomy

Introduction: Degenerative and dystrophic diseases of the lumbar spine in Russia rank 5th among the causes of hospitalization and 3rd among the causes of surgical treatment. Herniated discs are the most common degenerative disease of the lumbar spine causing low back pain and radicular symptoms in the lower extremities. Lumbar microdiscectomy has become one of the most common spinal surgeries. Various worldwide studies cite a postoperative recurrence rate ranging from 1.1% to 27.3%. Recurrences of herniated discs are one of the main reasons for revision surgeries in spinal surgery. Also in a number of cases, radicular pain syndrome persists after microdiscectomy, which may be associated with biochemical changes in the intervertebral disc. Through the annular defect inflammatory mediators (interleukins), cytokines and chemical agents are released from the pulposus nucleus, which cause irritation of the spinal ganglion and nerve root. Purpose of the study: to analyze the frequency and causes of recurrence of herniated discs after microdiscectomy and sequestrectomy according to the literature, which will allow us to develop a device to reduce the number of recurrencesMaterials and methods: we searched available literature sources, including PubMed and eLibrary databases, for the following keywords: «recurrence of disc herniation», «annulus fibrosus defect», «annulus fibrosus prosthesis», «lumbar disc reoperation», «annulus fibrosus defects», «annulus fibrosus prosthesis». The depth of the search was more than 20 years (2002-2023). As a result of the search, 108 articles were found and analyzed.Results: In our opinion and according to the literature, the most complete reduction in the number of disease recurrences is possible only with the help of mechanical obstruction of regenerate or intervertebral disc substance exit into the spinal canal by covering the intraoperative defect of the annulus fibrosus. We analyzed the devices, methods that were used earlier or are used now, formulated the requirements that, in our opinion, the implant should possess. Based on this, we came to the conclusion that at present there is no device that meets all the requirements. The time of implant degradation should coincide with the process of fibrous ring regeneration to ensure proper tissue remodeling. The change in the mechanical properties of the implant as a result of degradation must remain compatible with the repair and regeneration process. Finally, the implant should contribute to the restoration of normal spine biomechanics: restoration of IVD height; correct distribution of load on all areas of the IVD; restoration of physiologic volume of movement, lordosis; achievement of sagittal balance.Conclusion: Based on the analysis of the world literature data, we started to develop a biocompatible biodegradable device for filling the intervertebral disc cavity and closing the defect in the area of the annulus fibrosus after sequestrum and microdiscectomy to restore the biomechanics of the vertebral-motor segment in the lumbar spine and to eliminate postoperative recurrences. At present, the FGBNU «Petrovsky RRCS» together with SIC «Kurchatov Institute» are conducting laboratory tests of prototypes to study the static properties of materials and select the most suitable one