Decreases in the number and severity of morphometrically defined vertebral body deformities after kyphoplasty

Abstract

Vertebral body (VB) deformities have been associated with increased patient morbidity and mortality rates. The aim of this retrospective, consecutive single-center cohort study was to determine the effectiveness of kyphoplasty in reducing morphometrically defined VB deformity, including deformity shape types (wedge, biconcave, or crush) and grade (severity). The authors identified 100 patients (70% women; mean age 76.1 years) in whom 138 vertebral fractures (T-4 through L-5; mean fracture age 2.7 months) that were treated between May 2000 and December 2001 were radiographically evaluated preoperatively and at the last follow-up visit (mean follow-up duration 16.9 months). Fractures were divided into four groups by level: T5-9 (28 fractures), T10-12 (41), L1-2 (42), and L3-5 (27). Anterior, midline, posterior, and predicted posterior vertebral heights for fractured and adjacent unfractured reference vertebrae were measured on lateral radiographs. The deformity type and grade were mathematically defined using the modified methods of McCloskey-Kanis and Black. The total number of deformities decreased from 89.9 to 53.6% after kyphoplasty (p < 0.0001). The number of fractures with wedge, biconcave, or crush deformity decreased 22.5, 59.1, and 67.7% (p = 0.0699, p = 0.0222, p = 0.0007), respectively. The number of the more severe Grade 2 deformities decreased (79.7 to 37.0%; p < 0.0001). Kyphoplasty effectively decreased the number of deformed fractures in all vertebral level groups (T5-9, p = 0.0023; T10-12, p = 0.0105; L1-2, p < 0.0001; L3-5, p = 0.0028). Kyphoplasty resulted in significant normalization of vertebral shapes in patients with symptomatic vertebral fractures, reducing the number and severity of deformed fractures postoperatively.