Surgery vs Conservative Care for Cervical Spondylotic Myelopathy: Surgery Is Appropriate for Progressive Myelopathy.

Abstract

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction.1 The condition presents insidiously and is defined in terms of its clinical symptoms (gait instability, bladder dysfunction, fine finger motor difficulties) and signs (hyperreflexia, weakness, alteration of joint position sense). CSM is caused by dynamic repeated compression of the spinal cord from degenerative arthritis of the cervical spine.2 Proposed mechanisms include axonal stretch-associated injury2 and spinal cord ischemia from compression of larger vessels and impaired microcirculation.3,4 Surgery to decompress and stabilize the spine is often advocated for severe or progressive symptoms, with mixed results. About two-thirds of patients improve with surgery, while surgery does not result in improvement in 15%-30%.5 Over 112,400 cervical spine operations for degenerative spondylosis are performed annually in the US (100% increase over the past decade),6 with CSM accounting for nearly 20% of cervical spine operations in the US.7 Annual hospital charges for CSM surgery exceeds 2 billion dollars per year.6 In addition, CSM is associated with substantial postoperative outpatient expenses (e.g., physician visits, imaging, physical therapy, medications). Recently, the Institute of Medicine designated CSM as one of the top 100 national health research priorities for comparative effectiveness research.8 There is a great need for modern prospective studies with validated outcomes tools to assess the effectiveness of surgical treatments for CSM. Most American cervical spine experts (both orthopaedic and neurological surgeons) believe that there is sufficient clinical equipoise to support a comparative randomized clinical trial (RCT) if the study population is carefully defined.9 Most experts feel that surgery can prevent the progression of spinal cord dysfunction and can, in many cases, improve the symptoms of cervical spondylotic myelopathy. It is unclear, however, what the optimal surgical technique might be (ventral versus dorsal), and in up to 30% of cases the clinical outcome is not satisfactory.5 Furthermore, the complication rate for CSM surgery is high (17% in a recent prospective study),10 particularly in patients over 74 years of age,11 which is a growing segment of the US population.12 Lastly, the 5-year re-operation rate following surgery for CSM is nearly 15%.13