Background: We found a spontaneous fusion after percutaneous vertebroplasty (PVP) or kyphoplasty in osteoporotic compression fractures and analsze the radiologic & clinical characteristics.
Methods: Between January 2000 and January 2013, 555 patients were treated with PVP or kyphoplasty for osteoporotic compression fracture in our department. We classified the spontaneous fusion as two groups. One is absolute spontaneous fusion group with at least three cortical continuity to adjacent vertebrae, the other is partially fusion group which progressed fusion compared with previous radiologic finding. We reviewed the plain film and analysed the radiologic characteristics of those patients with duration of fusion, location and extent of fused segments. A clinical characteristic by visual analogue score (VAS) compared to our previous report was checked.
Results: Among them, 54 patients (9.7%) had an absolute spontaneous fusion and 43 patients (7.7%) had partially fused on plane image. In absolute fusion group, the average duration of fusion was 19 months ranged of 3 to 48 months. Forty-six cases (85%) of absolute fusion patients had occurred with proximal adjacent vertebrae and 7 cases (13%) had proximal with distal adjacent vertebrae. 41 cases (76%) of spontaneous fusion occurred within 1 segment and 13 cases within multiple segments. The most cases of absolute fusion group were occurred at thoracolumbar junction.(40 patients, 74%) Mean VAS score of absolute fusion group was 2.0 at final follow-up and were analysed relatively low score compared with mean VAS of our previous report (2.0, 2.8, respectively).
Conclusion: After percutaneous vertebroplasty or kyphoplasty in osteoporotic compression fracture, unpredictable spontaneous fusion could develop more than 10% rate, especially with proximal vertebra within 1 segment at thoracolumbar junction in radiologic aspect. Clinically, patients with spontaneous fusion had a tendency of more reduced pain than others.
Disclosure: The authors declared no competing interests.