Remarkable epidural scar formation compressing the cervical cord after osteoplastic laminoplasty with hydroxyapatite spacer

Case report

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The authors report on an 81-year-old woman whose condition deteriorated 2 months after undergoing osteoplastic laminoplasty with placement of hydroxyapatite spacers. Magnetic resonance imaging showed postlaminectomy scar formation compressing the cervical spinal cord. The patient underwent laminectomy and removal of remarkably thick epidural scar tissue, which resulted in resolution of her symptoms. Histological diagnosis of the scar was fibrous granulation tissue with foreign body granuloma, characterized by multinucleated giant cells and marked increases of capillary vessels, fibroblasts, and collagen fibers. This case of symptomatic postlaminectomy scar formation after osteoplastic laminoplasty suggests that osteoplastic laminoplasty cannot always prevent laminectomy membrane formation.

Abbreviation used in this paper: JOA = Japanese Orthopaedic Association.

Article Information

Address correspondence to: Keita Kuraishi, M.D., Ph.D., Spinal Disorders Center, Fujieda Heisei Memorial Hospital, 123-1 Mizukami, Fujieda, Shizuoka 426-8662, Japan. email:

Please include this information when citing this paper: published online August 12, 2011; DOI: 10.3171/2011.6.SPINE10930.

© AANS, except where prohibited by US copyright law.



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    A–C: Lateral radiographs of the cervical spine obtained before laminoplasty in flexion (A), neutral (B), and extension (C) positions, demonstrating slight kyphotic change without remarkable instability. D: Sagittal T2-weighted MR image obtained before laminoplasty showing compression of the dural tube from C3–4 to C5–6 levels and an intramedullary high-intensity area.

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    A: Lateral radiograph obtained 4 months after laminoplasty demonstrating adequate positioning of the hydroxyapatite spacers. B: Sagittal T2-weighted MR image of the cervical spine 1 month after the first operation showing decompression of the spinal cord with slight residual stenosis at the C5–6 level. C: Sagittal MR image obtained 3 months after laminoplasty demonstrating progression of cord compression.

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    A and B: Sagittal (A) and axial (B) T1-weighted MR images obtained after intravenous injection of gadolinium revealing massive epidural scar formation compressing the spinal cord. C: Axial CT images showing ideal positions of hydroxyapatite spacers without lamina subsidence or hinge fracture.

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    Intraoperative photographs obtained during the second operation showing the hydroxyapatite spacers and fibrous granulated tissue (A), casts with clear margins after removal of the spacers (B), and complete decompression (C).

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    Photomicrographs of sections from the epidural scar. A: Image showing fibrous granulation tissue with foreign body granuloma, characterized by multinucleated giant cells and marked increases of capillary vessels, fibroblasts, and collagen fibers. B: Image showing an example of the inorganic material, thought to be hydroxyapatite, that was included within the cytoplasm of the multinucleated giant cells. H & E, original magnification × 40 (A) and × 400 (B).

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    Sagittal T2-weighted MR image obtained 14 months after revision surgery demonstrating successful decompression of the spinal cord.



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