黄色靱帯骨化症

BACKGROUND: Thoracic ossification of the ligamentum flavum (T-OLF) is an important cause of progressive thoracic myelopathy and may be particularly debilitating in professional baseball pitchers, in whom surgical treatment must restore neural function while preserving the spinal biomechanics required for elite pitching. Although open laminectomy has traditionally been the standard treatment, extensive muscle dissection and disruption of posterior elements may compromise postoperative stability and return to play. OBSERVATIONS: The authors applied a refined full-endoscopic interlaminar decompression technique for single-level and multilevel T-OLF in professional pitchers. The key surgical strategy involved thinning the ossified lesion to a paper-thin shell and elevating it around a lateral hinge point, thereby minimizing direct vertical compression on the vulnerable thoracic spinal cord. When transient intraoperative neurophysiological monitoring deterioration occurred, staged decompression was performed to reduce neurological risk. LESSONS: Both patients showed marked neurological recovery and returned to professional pitching within 6 months, without evidence of biomechanical compromise. These findings suggest that full-endoscopic decompression, by preserving the posterior tension band and paraspinal musculature, may represent a viable primary surgical option for T-OLF in high-demand athletes requiring preservation of spinal mobility and kinetic chain function. https://thejns.org/doi/10.3171/CASE26537.

We present an exceptionally rare case of a late 30 s female with a known history of Cowden syndrome who developed extensive thoracic ossification of the yellow ligament (OYL) causing severe spinal cord compression. OYL is the abnormal ossification of the ligamentum flavum that can compress the spinal cord. The patient underwent a T10-11 posterior decompressive laminectomy and fusion that resulted in recovery of ambulatory function and improvement of motor strength. This case raises awareness of OYL as a potential, though unconfirmed, complication in patients with PTEN-related disorders, highlighting the possible value of spinal surveillance in this population.

Objective: To investigate the efficacy and safety of unilateral biportal endoscopy (UBE) for the treatment of thoracic myelopathy caused by thoracic ossification of the ligamentum flavum (TOLF). Methods: A retrospective case series analysis was conducted on the clinical data of 80 patients with short-segment (≤2 levels) TOLF who underwent UBE surgery at our institution between January 2020 and December 2024. The cohort comprised 44 males and 36 females with an age of (55.8±10.7) years (range: 34 to 76 years). Fifty-nine cases involved a single segment, and 21 cases involved two segments; 27 cases had concomitant dural ossification. Intraoperatively, a diamond burr was used to perform full-thickness drilling of the ossified ligamentum flavum, and the "floating technique" was applied in cases with dural ossification. Operative time, length of hospital stays, and perioperative complications were recorded. Spinal canal area and sagittal diameter were measured preoperatively, at postoperative day 3, and at the final follow-up. The Oswestry disability index (ODI) and Japanese Orthopaedic Association (JOA) score were assessed preoperatively, at postoperative day 3 and 3 months, and at the final follow-up. Repeated measures ANOVA was used to compare pre- and postoperative data, with pairwise comparisons adjusted using Bonferroni post-hoc tests. Results: All procedures were completed successfully without conversion to open surgery. The operative time was (141.4±44.6) min (range: 80 to 220 min), and the length of hospital stay was (11.7±5.5) d (range: 7 to 28 d). The follow-up period was (33.5±13.1)months (range: 12 to 60 months). Postoperative cerebrospinal fluid leakage occurred in 20 cases (25.0%, 20/80), all of which were associated with concomitant dural ossification or severe dural adhesion, and after conservative treatment, no cerebrospinal fluid leakage occurred. Epidural hematoma occurred in 3 cases (3.8%, 3/80), all of which were successfully managed by emergency endoscopic hematoma evacuation with subsequent recovery of muscle strength. Neurological deterioration due to improper drain placement occurred in 4 cases (5.0%, 4/80), all of which recovered to preoperative muscle strength levels by the final follow-up. Compared with preoperative values, spinal canal area and sagittal diameter were significantly increased at postoperative day 3 and at the final follow-up (all P<0.05). ODI and JOA scores showed significant improvement at all postoperative time points compared with preoperative values (all P<0.05). No symptom recurrence or neurological deterioration was observed at the final follow-up. Conclusions: UBE is an effective technique for the treatment of thoracic myelopathy caused by short-segment TOLF, achieving adequate spinal canal decompression and significant improvement in neurological function. Appropriate preoperative surgical approach planning and correct intraoperative decompression strategies are essential for ensuring surgical safety.

To delineate the dynamic transcriptomic landscape of ossification of the ligamentum flavum (OLF) across normal, immature, and mature stages, identify core genes, and screen stage-specific drug candidates. Normal, immature, and mature OLF tissues (nine samples) from three patients with multilevel OLF were collected for RNA-seq. Differential expression, functional enrichment, and dynamic trend analyses were performed. Key genes were validated using an external GEO dataset. Single-cell and spatial transcriptomics were integrated to determine cellular origin and spatial localization. AI-based drug prediction and molecular docking were conducted. Between normal versus immature, 1026 DEGs were identified; between immature versus mature, 713 DEGs; and between normal versus mature, 1285 DEGs. Upregulated genes were enriched in RNA processing and ribosome biogenesis, whereas downregulated genes were enriched in ECM-receptor interaction. LTBP4 showed progressive downregulation during ossification (AUC = 0.88). Single-cell transcriptomics and spatial transcriptomic analysis of a public multi-omics dataset (GSE255942) revealed that LTBP4 is expressed in fibroblasts, with lower expression in ossified than normal tissues. Virtual knockout of Ltbp4 in fibroblasts recapitulated the OLF transcriptomic signature. AI-based drug prediction identified stage-specific candidates; BRD-K59831625 exhibited the lowest binding energy with LTBP4 (-8.9 kcal/mol). Sustained LTBP4 downregulation drives OLF progression, with fibroblasts as core effector cells. Stage-specific drug candidates were identified. These findings provide new targets for molecular diagnosis and precision treatment of OLF.

BACKGROUND: Ossified ligamentum flavum (OLF) in the thoracic segments is a rare but significant cause of progressive myelopathy characterized by spinal canal stenosis. While OLF is commonly reported in East Asian populations, it remains under-recognized in other regions, including India. CASE PRESENTATION: We present a case of a 60-year-old Indian male laborer who developed progressive lower-limb weakness, sensory deficits, and immobility over several months. This case is notable for its occurrence in an Indian patient, within a population in which OLF remains significantly underreported, and for advanced neurological compromise (preoperative Medical Research Council [MRC] grade 2/5 bilaterally) and intraoperative dural ossification requiring complex surgical decision-making. Imaging revealed severe spinal cord compression at D10-D11 due to OLF, with associated dural calcification. Surgical decompression via laminectomy resulted in significant neurological improvement, with motor power improving to MRC grade 3/5 bilaterally and complete resolution of sensory deficits, highlighting the importance of timely intervention. CONCLUSION: This case highlights the need for increased awareness of OLF in underrepresented populations and emphasizes the critical role of advanced imaging and surgical management in achieving favorable outcomes. The rarity of reported cases of OLF from India and the presence of concurrent dural calcification further distinguish this report and highlight a diagnostic gap that warrants attention.