Dural Tears and Cerebrospinal Fluid Leakage in Anterior Cervical Spine Surgery: Mechanism, Management, and Repair Advances

What causes dural tears and cerebrospinal fluid leakage in anterior cervical spine surgery?

Dural tears and cerebrospinal fluid (CSF) leakage in anterior cervical spine surgery are primarily caused by adhesions between the dura mater and ossified posterior longitudinal ligament (OPLL), which eliminate the normal epidural dissection plane. During decompression procedures such as ACDF or ACCF, the rigid ossified ligament adheres tightly to the dura, making it highly susceptible to tearing even with minimal manipulation. Risk is significantly higher in OPLL patients, especially when dural ossification is present. Once a defect occurs, continuous pulsatile CSF pressure in the confined cervical space may prevent spontaneous sealing, leading to persistent leakage. Additional risk factors include revision surgery, trauma, infection, and long-term steroid use. Early recognition and layered biological repair strategies are essential for preventing complications.

Histological examination reveals the ossification process comprising both immature and mature OPLL.

Background – Why CSF Leakage Matters in Cervical Spine Surgery

Dural tears and cerebrospinal fluid (CSF) leakage are rare but clinically significant complications in anterior cervical spine surgery. Although the incidence is generally below 0.5% in standard ACDF or ACCF procedures, it increases dramatically in patients with ossification of the posterior longitudinal ligament (OPLL), reaching 4–32%. In cases with dural ossification, reported rates may exceed 60%.

These complications are associated with prolonged hospitalization, infection risk, neurological deterioration, and potential need for revision surgery.

Two-dimensional sagittal reconstructed CT images show the "double-track sign" (white arrows) (A, B).

Lateral X-ray and two-dimensional sagittal reconstructed CT images show OPLL with a "K-line negative" status (white arrows) (A, B).

Pathophysiology and Mechanism of Dural Injury

OPLL-Related Adhesion and Ossified Interface

The primary mechanism of dural injury is the loss of the normal epidural plane due to dense adhesion between the dura mater and the ossified posterior longitudinal ligament.

OPLL forms a rigid bone–fibrous complex that eliminates the natural separation between ligament and dura, making standard decompression hazardous.

Mechanical Vulnerability During Decompression

During anterior cervical decompression, even minimal manipulation may lead to:

• Micro-tears of the dura

• Incomplete separation of ossified mass

• Persistent CSF leakage under pulsatile pressure

Risk Factors for Dural Tears

Disease-Related Factors

• OPLL (highest risk)

• Dural ossification

• Severe spinal canal stenosis

Surgical and Patient Factors

• Revision surgery

• Trauma cases

• Chronic steroid use

• Prior infection or scarring

Radiological Predictors

• Double-layer sign

• Hook sign

• K-line negative alignment

• OPLL occupying >60% canal width

• 3D CT evidence of ossified dura interface

Surgical Strategy Evolution in OPLL

From Radical Resection to Floating Decompression

Earlier surgical strategies focused on complete removal of ossified ligament, which was associated with dural tear rates up to 30%.

Modern techniques emphasize:

• “Floating decompression”

• Partial thinning of ossified mass

• Preservation of adherent dura

This transition significantly reduced CSF leakage rates.

Management of Dural Tears and CSF Leakage

Intraoperative Repair Techniques

Stratified Bioaugmentation Strategy Based on Defect Size:

Postoperative Management

Key principles include:

Complications of Persistent CSF Leakage

Persistent leakage may result in:

• Wound swelling (30–40%)

• Infection risk (0.5–2%)

• Intracranial hypotension

• Rare intracranial hemorrhage

• Implant failure or subsidence

• Pseudomeningocele formation

• Reoperation (~5%)

Emerging Technologies in Repair

Future directions include:

• Bioactive hydrogels for dural sealing

• 3D-printed dural scaffolds

• AI-assisted imaging for risk prediction

• Regenerative biomaterials for dural healing

These technologies remain under clinical validation.

Conclusion

Dural tears and cerebrospinal fluid leakage in anterior cervical spine surgery are primarily driven by OPLL-related dural adhesion and ossification. Modern surgical management has shifted toward protective decompression and multilayer biological repair strategies. Early detection and standardized treatment significantly improve outcomes, while emerging biomaterials and digital technologies may further enhance future surgical safety.