Lateral radiograph 6 years ago
Recent lateral radiograph
A 42-year-old woman presents to the office with left shoulder pain radiating into the biceps for the past 2 months. She has a history of an anterior cervical discectomy and fusion (ACDF) 6 years ago for pain and weakness in the left triceps muscle. On examination, she has mild wrist extension weakness on the left. Lateral radiograph after ACDF 6 years ago is shown in Figure 1 and recent lateral radiograph in Figure 2.
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An anterior cervical discectomy and fusion (ACDF) is the most common surgical procedure to treat cervical spondylotic radiculopathy and myelopathy. An ACDF involves the removal of all disc material and a bony decompression at the level of pathology. Graft material is used to fill the disc space and fuse the vertebral bodies together. Fusion at one level causes hypermobility and increased stress at adjacent levels. This increased mobility of the cervical spine at adjacent levels causes accelerated degenerative changes at these levels, or a condition called adjacent segment degeneration. The incidence of adjacent segment degeneration after ACDF varies widely, but up to 90% of patients who undergo an ACDF may have adjacent segment degeneration. In contrast, patients with cervical spondylosis who do not have surgery have a 60% to 70% incidence of degenerative progression. This supports the fact that adjacent segment degeneration is not a condition of natural progression but rather caused by the biomechanical stresses of the ACDF. Not all patients with adjacent segment degeneration after ACDF will become symptomatic or require additional surgery. Of the patients who develop the condition, 9% to 17% of patients actually become symptomatic enough to require further surgery.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor-in-chief of the Journal of Orthopedics for Physician Assistants (JOPA).
- Rao RD, Gore DR, Tang SJ, Rebholz BJ, Yoganandan N, Wang M. Radiographic changes in the cervical spine following anterior arthrodesis: a long-term analysis of 166 patients. J Bone Joint Surg Am. 2016;98:1606-1613.
- Cho, SK, Riew DK. Adjacent segment disease following cervical spine surgery. J Am Acad Ortho Surg. 2013;21:3-11.