Risk Factors for the Occurrence of InsufficientCement Distribution in the Fractured Area afterPercutaneous Vertebroplasty in OsteoporoticVertebral Compression Fractures

BACKGROUND: Insufficient cement distribution (ICD) in the fractured area has been advocated to be responsible for unsatisfied pain relief after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs). However, little is known about risk factors for the occurrence of ICD. OBJECTIVE: The present study aimed to identify independent risk factors of the emergence of ICD. STUDY DESIGN: A retrospective cohort study. SETTING: Department of spinal surgery, an affiliated hospital of a medical university. METHODS: Patients who underwent PVP for single-level OVCF from January 2012 to September 2014 and met this study's inclusion criteria were retrospectively reviewed. Associations of ICD with co-variates (age, gender, bone mass density with a T-score, amount of injected cement, cement leakage, fracture level, fracture age, fracture severity grade, and location of the fractured area) and the influence of ICD on pain relief were analyzed. RESULTS: A total of 225 patients were included. ICD was found in 26 (11.6%) patients. Fractured area located in the superior portion of the index vertebra was significantly associated with occurrence of ICD. No further significant associations between the studied co-variates and emergence of ICD were seen in the adjusted analysis. In addition, patients with ICD had significantly higher immediate postoperative visual analog scale scores of back pain compared with those with sufficient cement distribution in the fractured area. LIMITATION: Location of the fractured area and cement distribution in the fractured area could not be evaluated quantitatively. CONCLUSIONS: The incidence of ICD is higher in patients with the fractured area located in the superior portion of the index vertebra and ICD might be responsible for unsatisfied pain relief after PVP for OVCFs. KEY WORDS: Percutaneous vertebroplasty, insufficient cement distribution, fractured area, risk factor, osteoporosis, vertebral compression fracture, spine, unsatisfied pain relief, cement augmentation.