A study published in the Journal of Spinal Disorders & Techniques examines which radiographic parameters are predictive of the clinical outcomes of spinal disc replacement procedures.
The researchers analyzed radiographic parameters and clinical outcomes of cervical disc replacement patients who underwent surgery in the Discover artificial cervical disc investigative device exemption trial. There were 243 patients included who had surgery at 304 levels; there were 182 one-level procedures and 61 two-level procedures.
Here are five findings from the study:
1. Patients with a preoperative disc height less than 3.5 mm were associated with a 3.4 times greater risk of not achieving a minimal clinically important difference in the Neck Disability Index score.
2. When the functional spinal unit angle increased by more than three degrees, there was a 3.5 times greater risk of not reaching a minimal clinically important difference in NDI.
3. There were 21 patients who didn't achieve the minimal clinically important difference in NDI threshold; all of those patients had at least one abnormal radiographic finding and 16 had multiple abnormal radiographic findings.
4. Among the levels treated, 70 percent had severe or bridging heterotopic ossification at three years after surgery.
5. Severe or bridging heterotopic ossification incidences increased linearly over time.