Disc Arthroplasty¶

Overview¶

Disc arthroplasty (artificial disc replacement) is a motion-preserving alternative to fusion for degenerative disc disease, primarily performed in the cervical spine (C3–C7) and less commonly in the lumbar spine. The prosthetic disc replaces the native disc and maintains segmental mobility, theoretically reducing adjacent segment degeneration compared to fusion.

Imaging¶

Radiography¶

• Prosthesis position and alignment
• Dynamic flexion-extension views confirm preserved motion at the operative level
• Heterotopic ossification grading (can reduce or eliminate motion)

CT¶

• Detailed assessment of device position
• Heterotopic ossification around the device
• Subsidence into the endplates

MRI¶

• Limited by metal artifact (varies by device material)
• Evaluate adjacent segments and the cord

Complications¶

• Heterotopic ossification — Bone formation around the device that can eliminate the intended motion, effectively converting to a spontaneous fusion
• Device migration or subsidence — Movement or sinking of the prosthesis into the endplates
• Wear and loosening — Long-term concerns
• Adjacent segment degeneration — Still occurs, though potentially at a lower rate than after fusion

Key Points¶

• Motion-preserving alternative to fusion, primarily cervical
• Flexion-extension radiographs confirm preserved motion
• Heterotopic ossification is the most common complication
• Metal artifact limits MRI evaluation — CT is better for device assessment
• Adjacent segment degeneration may still occur

References¶

1. Mehren C, Suchomel P, Grochulla F, et al. Heterotopic ossification in total cervical artificial disc replacement. Spine (Phila Pa 1976). 2006;31(24):2802-6. PMID: 17108833. doi:10.1097/01.brs.0000245852.70594.d5
2. Murtagh RD, Quencer RM, Cohen DS, Yue JJ, Sklar EL. Normal and abnormal imaging findings in lumbar total disk replacement: devices and complications. Radiographics. 2009;29(1):105-18. PMID: 19168839. doi:10.1148/rg.291075740
3. Robinson Y, Sandén B. Spine imaging after lumbar disc replacement: pitfalls and current recommendations. Patient Saf Surg. 2009;3:15. PMID: 19619332. doi:10.1186/1754-9493-3-15
4. Jin YJ, Park SB, Kim MJ, Kim KJ, Kim HJ. An analysis of heterotopic ossification in cervical disc arthroplasty: a novel morphologic classification of an ossified mass. Spine J. 2013;13(4):408-20. PMID: 23332520
5. Petscavage-Thomas JM, Ha AS. Imaging current spine hardware: part 1, cervical spine and fracture fixation. AJR Am J Roentgenol. 2014;203(2):394-405. PMID: 25055276. doi:10.2214/AJR.13.12216
6. Byvaltsev VA, Kalinin AA, Aliyev MA, Riew KD. Postoperative MRI visualization of the cervical spine following cervical disc arthroplasty: a prospective single-center comparison of a titanium and cobalt-chromium prosthesis. Global Spine J. 2023;13(1):67-73. PMID: 33504201. doi:10.1177/2192568221991105
7. Cervical disc arthroplasty. Radiopaedia.org. https://radiopaedia.org/articles/cervical-disc-arthroplasty
8. Lumbar disc arthroplasty. Radiopaedia.org. https://radiopaedia.org/articles/lumbar-disc-arthroplasty

Related Articles¶

• ACDF
• Adjacent Segment Disease