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Updated: Jan 9, 2026
Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum TOLF Using Ultrasonic and Conventional Osteotomes
Published on: April 21, 2023
Impact of Posterior Cord Compression from Ligamentum Flavum on Clinical Outcomes Following ACDF or CDR
Andrea Pezzi1, Tomoyuki Asada1, Atahan Durbas1
1Department of Spine Surgery, Hospital for Special Surgery, 535 E 70th St, New York, (NY), USA, 10021.
Insights
Hypertrophied ligamentum flavum (HLF) did not significantly impact outcomes after anterior cervical discectomy and fusion (ACDF) or cervical disc replacement (CDR). Both ACDF and CDR showed significant improvements in patient-reported outcomes.
Area of Science:
- Spine surgery
- Degenerative cervical spine disease
- Cervical myelopathy
Background:
- Hypertrophied ligamentum flavum (HLF) contributes to cervical myelopathy and spinal cord compression.
- The impact of HLF on outcomes following anterior cervical discectomy and fusion (ACDF) is debated.
- The role of cervical disc replacement (CDR) in patients with HLF is not well-defined.
Purpose of the Study:
- To determine the impact of hypertrophied ligamentum flavum (HLF) on patient-reported outcomes after ACDF and CDR.
- To compare the effectiveness of ACDF versus CDR in patients with HLF.
Main Methods:
- Retrospective cohort study of 228 patients undergoing 1- or 2-level ACDF or CDR for cervical myelopathy/myeloradiculopathy.
- HLF status was dichotomized (Non-HLF vs. HLF, with HLF further categorized as mild or severe).
- Longitudinal outcomes assessed using Neck Disability Index (NDI), Numerical Rating Scale (NRS), and SF-12 PCS via multivariable linear mixed-effects models (LMMs), including IPTW-adjusted analyses.
Main Results:
- Both ACDF and CDR groups showed significant improvements in NDI, NRS neck, and NRS arm over time.
- HLF status did not significantly influence outcomes in either ACDF or CDR cohorts.
- IPTW-adjusted comparisons in HLF patients revealed no significant difference in NDI trajectories between ACDF and CDR.
Conclusions:
- HLF does not significantly affect outcomes following ACDF or CDR for cervical myelopathy/myeloradiculopathy.
- CDR can be considered for carefully selected patients with mild HLF, offering significant improvements in patient-reported outcomes.
- Findings challenge traditional views on excluding patients with HLF from CDR.
Study Design:
Retrospective cohort study.
Objective:
To determine the impact of hypertrophied ligamentum flavum (HLF) on outcomes following anterior cervical discectomy and fusion (ACDF) and cervical disc replacement (CDR).
Summary Of Background Data:
HLF contributes to spinal cord compression in cervical myelopathy. While ACDF's effectiveness in decompressing HLF is debated and severe HLF may worsen its outcomes, CDR's role with HLF is unclear.
Material And Methods:
A retrospective study was performed on patients following 1- or 2-level ACDF or CDR for cervical myelopathy or myeloradiculopathy. Patients with cervical deformity, fracture, or OPLL were excluded. HLF was dichotomized as Non-HLF and HLF based on previously reported HLF grading. HLF group, was then categorized in "severe" and "mild" cases. PROMs included Neck Disability Index (NDI), Numerical Rating Scale (NRS) for neck and arm, and SF-12 PCS. Multivariable linear mixed-effects models (LMMs) were used for longitudinal outcome assessments including three-way interaction term among postoperative time, ACDF or CDR, and HLF. IPTW-adjusted LMM was utilized to compare outcomes in patients with HLF between ACDF and CDR.
Results:
A total of 240 patients were assessed, of whom 228 met the inclusion criteria, with 160 ACDF and 68 CDR. Both groups experienced significant improvements in NDI, NRS neck and arm over time (F(5, 835.67)=70.03, P<0.001). HLF status did not significantly influence these outcomes in both ACDF and CDR cohorts (F(5, 835.68)=0.65, P=0.66). Subgroup analyses by existing of radiculopathy, and number of surgical levels revealed no significant impact of HLF. IPTW-adjusted comparisons in HLF patients with balanced-cohort showed no significant difference in NDI trajectories between ACDF and CDR (F(5, 472.19)=1.30, P=0.26).
Conclusion:
CDR can be offered to carefully selected patients with mild HLF, challenging the traditional view that excludes them from arthroplasty, with significant improvements in patient-reported outcomes.
