Outcome assessment
blood loss, pain
BLOOD LOSS, LEAKAGE
Radiological assessment was done by a blinded radiologist while functional assessment was done by another blinded assessor. Baseline data included gender, age, body mass index (BMI), bone mineral density (BMD), the time from injury to surgery, affected lumbar level, vertebral body height ratio, and VAS scores. If injury time was uncertain, the onset of back pain was recorded. Vertebral height was presented as anterior, middle, and posterior vertebral body height ratios, which were measured on lateral radiographs. Assessment during operation involved operation time, fluoroscopic times, injected cement volume, and occurrence of cement leakage. The cement leakage was defined as leakage in any direction extraosseously. The hidden blood loss was evaluated as the reduction of perioperative hemoglobin value. Following the surgery, all patients underwent both functional (VAS scores) and radiological (anterior–posterior and lateral images) assessments at postoperative 1 day, 1, 3, 6, and 12 months of follow-up. If a participant failed to visit assessors in our hospital, telephone contact was carried out. Radiographs could be performed at local hospitals and sent to us via WeChat or Email. The intention to treat principle was used for missing data.