What are the types and treatments of spinal disc displacement?

Spinal Disc Displacement: Types and Treatment Approaches

Classification of Disc Displacement

Spinal disc displacement is categorized into distinct pathological types based on the nature of herniation, each requiring specific treatment strategies. 1

Primary Pathological Types

Damage-Herniation Type (Soft Disc Herniation)

• Characterized by soft herniation typically caused by acute injury 1
• The disc capsule is easily cut, with broken disc tissue that overflows or is easily removed 1
• Represents the "extruded or sequestered type" of disc herniation 2
• Complete removal of broken disc substances is required 1
• Responds well to minimally invasive endoscopic surgery 1
• Noncontained disc herniations of this type typically have a shorter clinical course and rarely require surgery if symptoms can be tolerated for the first 2 months 3

Degeneration-Protrusion Type (Hard Disc Protrusion)

• Characterized by hard and tough protrusions resulting from degenerative and proliferative processes 1
• The pathological process involves degeneration with proliferative reaction 1
• Treatment focuses on nerve decompression and relaxation with minimally invasive removal of the posterior wall 1
• The bulged or protruded disc often does not require excision 1
• Contained disc herniations of this type typically have a longer preoperative clinical course 3

Posterior Vertebral Osteochondrosis with Disc Protrusion

• Features deformity of the posterior vertebral body with osteochondral nodules and intervertebral disc protrusion 1
• Requires removal of herniated and fragmented disc tissue along with partially protruding osteochondral nodules 1

Intervertebral Disc Cyst

• Characterized by a cyst that communicates with the disc 1
• Pathogenesis remains uncertain 1
• Resection of the cyst under microscopic or endoscopic control achieves good results 1
• Whether simultaneous resection of the affected disc is necessary remains controversial 1

Anatomical Classification by Location

Central-Paracentral Type

• Disc material extrudes in a central or paracentral direction 2
• Commonly associated with root pain complications 2

Posterolateral Type

• Disc material extrudes in a posterolateral direction 2
• Also shows complications of root pain 2

Treatment Strategies Based on Disc Type

Conservative Management

Initial Conservative Treatment Duration

• Conservative treatment of at least 2 months' duration is recommended for all patients with lumbar disc herniation 3
• This approach significantly reduces the number of herniotomies required, especially for noncontained disc herniation 3
• Patients with noncontained lumbar disc herniation can often be treated without surgery if symptoms can be tolerated for the first 2 months 3

Conservative Treatment Modalities

• Multiple treatment options exist, though evidence for drug treatments is limited 4
• Conservative measures provide relief for most patients 5

Surgical Indications and Approaches

For Damage-Herniation Type (Soft Disc)

• Minimally invasive endoscopic surgery is the preferred approach 1
• Complete removal of broken disc substances is essential 1
• In cervical spine cases, half of soft disc herniation cases required removal of extruded disc material, while others improved with conservative treatment 2

For Degeneration-Protrusion Type (Hard Disc)

• Minimally invasive removal of the posterior wall for nerve decompression 1
• The protruded disc itself often does not require excision 1

For Posterior Vertebral Osteochondrosis

• Surgical removal of herniated disc tissue and partially protruding osteochondral nodules 1

For Disc Cysts

• Microscopic or endoscopic resection of the cyst 1

Fusion Considerations

Primary Disc Herniation with Radiculopathy

• Routine fusion at the time of primary lumbar disc excision is NOT recommended 6
• Level III evidence shows no statistically significant difference in functional outcomes between discectomy alone versus discectomy with fusion (p = 0.31) 6
• The definite increase in cost and complications associated with fusion are not justified in routine situations 6, 7
• Discectomy alone resulted in 70% return to work versus 45% in the fusion group 6

Specific Indications for Fusion at Primary Discectomy

• Manual laborers or athletes with significant preoperative axial low-back pain 6
• Patients with preoperative lumbar instability (though incidence is very low, <5% in general disc herniation population) 6
• Presence of radiographic instability or deformity 6

Recurrent Disc Herniation

• Reoperative discectomy alone provides satisfactory outcomes similar to primary disc excision 6
• Good outcomes demonstrated in 69-85% of patients with reoperative discectomy alone 6
• Fusion at revision discectomy is recommended primarily for patients with associated lumbar instability, radiographic degenerative changes, chronic axial low-back pain, or spondylolisthesis 6, 7
• Patients with "simple" recurrent herniation without instability do not require fusion 7
• In recurrent herniation with low-back pain and spondylolisthesis, fusion yields 93% patient satisfaction and 82% radiographic fusion rates 6

Critical Pitfalls to Avoid

Timing of Surgical Intervention

• Avoid premature surgery for noncontained disc herniation, as these rarely require surgery if symptoms can be tolerated for 4 months or more after onset 3
• Ensure adequate conservative treatment duration (minimum 2 months) before considering surgery 3

Inappropriate Fusion

• Do not perform routine fusion for isolated disc herniation without instability 6, 7
• The increase in morbidity, cost, and potential complications associated with routine fusion are not justified 7

Pathological Type Recognition

• Accurately identify the pathological type of disc displacement, as this dictates the appropriate surgical technique 1
• For degeneration-protrusion type, avoid unnecessary disc excision when nerve decompression alone is sufficient 1