Progression of Ossification Common After Spinal Fusion
High percentage of patients with mild ossification progress to advanced ossification
TUESDAY, Dec. 11 (HealthDay News) -- In patients treated with anterior cervical arthrodesis with plates, those developing degenerative changes in adjacent discs within one year after surgery have a high likelihood of progressing to advanced ossification by two years, reports a study published in the November-December issue of the Spine Journal.
Jong-Beom Park, M.D., Ph.D., of Washington University School of Medicine in St. Louis, and colleagues compared the timing of adjacent-level ossification in 62 patients treated with cervical arthrodesis whose plate-to-disc distance (PDD) was less than 5 mm versus equal to 5 mm.
Patients who had any ossification in adjacent levels by three, six or 12 months had a high likelihood of progressing to advanced ossification by 24 months (87.5 percent, 62.5 percent and 37.5 percent, respectively). For those without ossification at three or six months, a substantial percentage still developed ossification by 24 months (23.5 percent and 14.9 percent, respectively), while only 1.8 percent of those without ossification at 12 months progressed to advanced ossification. Ossification rates were higher when the PDD was less than 5 mm compared to greater than 5 mm.
"We conclude that any ossification within the first postoperative 12 months has a substantial likelihood of progression on to advanced ossification by 24 months. However, if a patient has no ossification at 12 or 24 months or only mild ossification at 24 months, it is very unlikely for advanced ossification to develop," the authors write.