Adjacent disc height reduction and clinical outcome after intradiscal cement leakage

Abstract

Objective: The purpose of this study is to evaluate the effect of intradiscal cement leakage on the height of adjacent cement-containing discs and the resulting clinical efficacy after kyphoplasty.

Methods: A total of 124 patients were included and classified into two groups: group A included 20 patients with intradiscal leakage, and group B contained 104 patients without intradiscal leakage. The mean follow-up time was 20.56±3.51 months. The height of the corresponding discs in both groups was measured using Farfan's method. Clinical efficacy was assessed using the Visual Analog Scale and Oswestry Disability Index scores at each follow-up time.

Results: The anterior disc height, posterior disc height and Farfan Index significantly decreased in both groups at last follow-up. The disc height reduction was 9.19±2.89% in group A and 3.88±2.70% in group B, which was significantly different between the groups (P<0.01). The disc height reduction rate was 29.39±7.90% in group A and 12.75±8.18% in group B, which was also a statistically significant difference (P<0.01). The VAS and ODI scores improved significantly after surgery and maintained at last follow-up, and there was no statistically significant difference between Groups A and B.

Conclusion: Intradiscal cement leakage was associated with the degeneration of cement-containing disc but did not reduce the clinical efficacy at early stages.

Keywords: clinical efficacy; disc height reduction; intradiscal cement leakage; percutaneous balloon kyphoplasty.

Fig. 1

Measurement of disc height (A) and disc diameter (B). Anterior disc height (Ha) and posterior disc height (Hp) were the shortest distances between the anterior and posterior edges of the neighboring endplates, respectively. Lines a and b (black lines) were drawn from the anterior and posterior endpoints of the superior vertebral endplate to the inferior, respectively. Disc diameter (DM, white line) was measured between the midpoints of line a and b.

Fig. 2

A 70-year-old female who suffered from a vertebral compression fracture at T12. Lateral radiograph 19 months postoperatively (B) shows disc height reduction compared with the image one day after surgery (A). The Farfan index was 34.55% and 24.97% on lateral radiograph one day after surgery (A) and 19 months postoperatively (B), respectively.