Cervical Disc Arthroplasty for Myelopathy in McCune-Albright Syndrome
Siraj Shaikh, Daniel Coban, George Abdelmalek, Ahmad Abu Awwad, Jibran Khan, Arash Emami, Nikhil SahaiStudy Design:
Case report.
Objective:
To describe cervical disc arthroplasty (ACDR) for cervical myelopathy in a patient with McCune-Albright syndrome (MAS) and polyostotic fibrous dysplasia (FD), a context in which poor bone quality is often viewed as a contraindication to arthroplasty.
Summary of Background Data:
MAS is a rare genetic disorder caused by somatic mutations in the GNAS gene, activating the Gsα-cAMP signaling pathway. The syndrome is characterized by FD, café-au-lait spots, precocious puberty, and endocrinopathies. Spinal FD may cause instability or cord compression, and fusion has traditionally been the preferred surgical approach due to concerns about fixation in dysplastic bone. Reports of successful arthroplasty in MAS are rare. Case: A 39-year-old woman with MAS and polyostotic FD presented with progressive neck pain, bilateral paresthesias, and right-hand weakness. Imaging demonstrated C6–C7 spondylosis with a central disc herniation causing ventral spinal cord compression. Given myelopathy, intact facets, and acceptable endplate integrity, ACDR at C6–C7 was planned with a predefined contingency to convert to fusion if intraoperative bone quality proved unsuitable.
Results:
Anterior decompression with C6–C7 ACDR was performed uneventfully with stable neuromonitoring and minimal blood loss. At two weeks, the patient reported marked symptom improvement; by six weeks, strength was full and physical therapy commenced. At 18-month follow-up, radiographs demonstrated stable implant position and alignment. MRI showed expected postoperative changes without migration or subsidence. Neurological function and pain relief were sustained. No heterotopic ossification was identified on interval radiographs.
Conclusions:
This case demonstrates that cervical disc arthroplasty can be a safe and effective option for myelopathy in carefully selected MAS patients with adequate bone quality and stable alignment. Under appropriate conditions, motion preservation may offer an alternative to fusion in metabolic bone disease traditionally considered a contraindication to arthroplasty.