Progressive disc herniation often occurs to the annulus over the course of many individual injuries.
Disc herniation is now classified into protrusion, extrusion, sequestered as well as contained or not contained. It is often progressive in nature. It all begins with radial tears to the inner most annulus when the lemellae delaminate as the hydraulic stresses out compete the tensile strength between the endplates.
As the outer annulus is innervated, continued stress and tearing to the fibres can begin to reach the innervation of the disc. Repetitive flexion pushes the nucleus pulposus posterior into the sensitive outer third of the anulus. When this fissure becomes chronically spread apart, often granulation tissue forms around the tear causing intradiscal inflammation. It is now believed that disc innervation is similarly innervated like an organ with sympathetic nerves which is why it may lead to chronic spinal pain syndromes. When these nerves (sinuvertebral nerves) embedded in the posterior annulus are irritated from the stresses of the nucleus–often done in lumbar and cervical flexion– people often complain of morning stiffness. This is a cardinal sign of degenerative disc.
Dynamic Disc Designs manufactures models that provide the practitioner with models to describe a patient’s spinal symptoms. Whether the concept of nerve root entrapment due to extrusion requires surgery, or the patient is experiencing facetogenic pain due to disc height loss and would respond to manipulation, or the patient has a symptoms of stenosis due to a thickened ligamentum flavum and experiences bilateral leg symptoms after a period of walking, these new dynamic models are helpful in the connecting what doctors know and what patients are often confused about. ddd hopes to build better doctor patient communication through more effective spine education for all spine professionals.
Dr. Jerome Fryer, the founder of ddd, has been lecturing on topics of education to professionals to help improve outcomes for spine.