Wang 2015

Methods	Design: single‐centre, parallel‐group, two‐arm randomised controlled trial Setting: China Timing: 1 January 2012 to 12 February 2014 Interventions: high‐viscosity cement vertebroplasty versus balloon kyphoplasty Sample size:a priori sample size calculation not reported Analysis: intention‐to‐treat analysis planned
Participants	Number of participants 152 patients assessed for eligibility 45 patients excluded (32 did not meet inclusion criteria, 13 refused to participate) 107 enrolled and randomised (53 to vertebroplasty, 54 to balloon kyphoplasty) Data for 105 (53 for vertebroplasty, 52 for kyphoplasty) available at 3‐month assessment Data for 101 (50 for vertebroplasty, 51 for kyphoplasty) available at 12‐month assessment Inclusion criteria Recent lumbar or thoracic vertebral compression fractures (proven by radiographs and MRI) Unsatisfactory pain relief (VAS equal to or more than 5) after at least 4 weeks conventional therapy Confirmed diagnosis of osteoporosis or osteopenia (proven by DEXA) Exclusion criteria Burst fractures Infection Radicular syndrome Primary bone tumours Spinal metastases Baseline characteristics Vertebroplasty group Mean (SD) age: 69.43 (8.94) years; 77.4% female: 22.6% male Mean (SD) VAS pain score: 8.10 (1.23) Mean (SD) ODI score: 71.22 (10.56) Mean (SD) compression rate: 29.98 (18.12) Balloon kyphoplasty group Mean (SD) age: 68.63 (8.39) years; 74.1% female: 25.9% male Mean (SD) VAS pain score: 8.04 (1.13) Mean (SD) ODI score: 71.30 (10.22) Mean (SD) compression rate: 28.67 (19.31)
Interventions	A unipedicular approach was adopted in all patients in this study. Injected cement volume was recorded for patients in both treatment groups. The endpoint of cement injection for both techniques was the presence of radiologically‐adequate filling, the start of leakage, and/or significantly increased pressure during injection. High‐viscosity cement vertebroplasty Vertebroplasty consists of injecting cement into a collapsed vertebra in order to reinforce the fractured vertebra and gain pain relief. The Confidence Spinal Cement System (DePuy Spine Inc, USA) was used. Balloon kyphoplasty An inflatable balloon is inserted into a collapsed vertebral body. Once inflated, the balloon elevates the endplates and creates a cavity. Then the cement is injected at a low pressure into the cavity of the collapsed vertebral body. Injecting cement into a cavity under low pressure reduces the risk of cement leakage. The Kyphon system (USA) was used. A low‐viscosity cement was used (OSTEOPAL V, Heraeus Medican GmbH, Germany) Follow‐up care After the procedure all patients remained supine in bed for 24 hours, and were referred for treatment with calcium and vitamin D supplements, and anti‐resorptive or anabolic agents.
Outcomes	Outcomes were measured at baseline, 1 day, 3 months, and 1 year after treatment. A primary outcome was not specified. Outcomes reported VAS mean pain score (scale and time period not specified) Oswestry Disability Index (ODI) Assessment of cement leakage (based on radiographs, supplemented by postoperative CT scans) Location of leakage (classified as disk space, epidural space, paravertebral areas, or peripheral veins) Changes of the anterior vertebral body height Compression rate (predicted height minus preoperative anterior height, divided by predicted height) Height of restoration rate (post‐operative fracture height minus preoperative fracture height divided by 100 minus preoperative fracture height) Outcomes included in this review Mean pain Oswestry Disability Index (ODI) Adverse events Incidence of new vertebral fractures
Source of funding	Funding source not stated.
Notes	Clinicaltrials.gov trial identifier: not reported. No published protocol found. Triallists reported leakage in 9/68 vertebral joints in the vertebroplasty group and 22/72 joints in the kyphoplasty group, but did not report the number of participants with leakage.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Patients were reportedly randomised into treatment groups, however randomisation method is not reported.
Allocation concealment (selection bias)	Unclear risk	Whether or not treatment allocation was concealed is not reported.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: “Patients were blinded to which group they were assigned.” Not reported whether personnel were blinded to treatment allocation.
Blinding of outcome assessment (detection bias) Self‐reported outcomes (e.g., pain, disability)	Low risk	Quote: “Patients were blinded to which group they were assigned.”
Blinding of outcome assessment (detection bias) Objective outcomes (e.g., radiographic outcomes)	High risk	Not reported whether radiographers were aware of treatment. However, they would be able to tell the difference between vertebroplasty and balloon kyphoplasty on a radiograph. It is stated that blinded data about cement leakage and vertebral body height were collected by radiologists.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data were unavailable for 0 (0%) and 2 (3.3%) participants in the vertebroplasty and balloon kyphoplasty groups respectively at the 3‐month follow‐up. Data were unavailable for 3 (5.7%) and 3 (5.6%) participants in the vertebroplasty and balloon kyphoplasty groups, respectively at the 12‐month follow‐up.
Selective reporting (reporting bias)	Unclear risk	No protocol found. Pain, ODI and vertebral body height data were excluded from participants who had a further vertebral fracture during follow‐up.
Other bias	Low risk	None apparent.