Endres 2012

Methods	Design: two‐arm open‐label single‐centre quasi‐randomised controlled trial Setting: Germany Timing: not stated Interventions: percutaneous vertebroplasty, balloon kyphoplasty or shield kyphoplasty Sample size:a priori sample size calculation not reported Analysis: completers' analysis
Participants	Number of participants Numbers screened for eligibility and number excluded or declined to participate is not stated. 66 participants quasi‐randomised (22 to each of the three groups) Data for 59 (21/22 (95%) for vertebroplasty, 20/22 (91%) for balloon kyphoplasty and 18/22 (82%) for shield kyphoplasty available at the 6‐month follow‐up. Two participants were deceased at the time of follow‐up and five refused to participate and these participants were excluded from the analysis. Inclusion criteria Patients with osteoporosis proven on DXA scan Fresh painful single‐level vertebral fracture in middle and lower thoracic spin. Symptom duration 6 weeks or less Magnetic resonance imaging demonstrating oedema in the affected vertebral body Conservative treatment (analgesics according to the WHO scheme, physiotherapy, physical therapy, orthotics adjustment) ineffective for at least 4 weeks Provoked percussion pain in the spinous process agreed with the site of the radiologically proven compression fracture Exclusion criteria No painful vertebral deformation or considerable degenerative damage Vertebral deformation (e.g. vertebra plana) Tumour and metastasis Local or systemic infection Untreated clotting disorder Baseline characteristics Vertebroplasty group: Mean (range) age: 71.3 (63‐77) years; 12 female:8 male (gender of one participant not specified) Prevalent vertebral fractures at baseline: 1 Mean (SD) baseline pain score: 78.2 (9.36) Mean (SD) baseline Oswestry Disability Index: 68.2 (5.7) Balloon kyphoplasty: Mean (range) age: 63.3 (53‐77) years; 14 female:6 male Prevalent vertebral fractures at baseline: 1.25 (range 1 ‐ 3) Mean (SD) baseline pain score: 90.0 (7.07) Mean (SD) baseline Oswestry Disability Index: 77.0 (4.2) Shield kyphoplasty: Mean (range) age: 67.1 (47‐79) years; 14 female:4 male Prevalent vertebral fractures at baseline: 1.14 (range 1‐2) Mean (SD) baseline pain score: 88.16 (15.06) Mean (SD) baseline Oswestry Disability Index: 75.7 (9.1)
Interventions	All procedures were performed by the same orthopaedic surgeon under biplane fluoroscopy and general anaesthesia. Vertebroplasty This was performed through a unipedicular transpedicular approach with one 13‐gauge bone biopsy needle (Stryker) placed in the anterior third of the vertebral body. Once the needle was in place, liquid and powder PMMA (high viscosity SpinePlex, Stryker, Germany) were mixed to toothpaste consistency. Under biplane guidance, the cement was injected through the needle until the vertebral body was filled in the posterior 25% or until there was leakage. No postural manoeuvre was performed to retain alignment before or during the procedure. Balloon kyphoplasty This was also performed through a unipedicular approach with a unilateral working cannula and standard kyphoplasty equipment (high viscosity KyphX HV‐R, Medtronic, Germany). A drill passing through the cannula created a tract for the 20 mm balloon to be inserted in the centre of the vertebral body. Cement, mixed according to the manufacturer's recommendations, was injected as described for vertebroplasty. Injection was usually about 14 minutes after start of mixing. Shield kyphoplasty The Soteira shield kyphoplasty is a percutaneous minimally invasive system that enables a fractured vertebral body to be accessed through a unipedicular approach. The implant site was prepared by manually creating a cavity, and bone cement (Soteira, high viscosity) was delivered via an implantable cement director, the Shield Implant. This is a hollow, self‐expandable, coated implant that is marketed in a range of sizes and is attached to a disposable delivery system. Follow‐up All participants were discharged 2 days after surgery. All participants received daily standard doses of oral aminobisphosphonate, 1000 mg calcium and 1000 IU vitamin D3. In addition, physiotherapy and pain medication was prescribed as required.
Outcomes	Outcomes were reported immediately postoperatively and a mean of 5.8 months (range: 4 to 7 months) after treatment. Primary outcomes Mean pain, measured on a VAS scale (scale not specified but appeared to be on a 0 to 100 scale) Mean disability, measured by the Oswestry Low Back Disability Index (ODI), 0 to 100 scale (0 is no disability) Secondary outcomes Beck Index (assesses vertebral height) Surgery and fluoroscopy times Dose‐area product (cGy x cm2) Cement leakage Incidence of new adjacent vertebral fractures Other adverse events Outcomes included in this review Mean pain Disability as measured by the ODI Incidence of new vertebral fractures Adverse events
Source of funding	BioMedEs funded translation and copyediting. It is not reported whether or not other funding was received.
Notes	Trial registration: not found. The authors stated that there were no significant differences in baseline characteristics between groups but the review authors judged there to be significant pre‐treatment group differences: there were significant differences between groups with respect to age (mean age of participants in the vertebroplasty group was greater than the other groups) and participants allocated to the kyphoplasty groups appeared to have worse scores for pain and ODI at baseline compared with the vertebroplasty group. We extracted data from vertebroplasty and balloon kyphoplasty groups only. We converted the 0 to 100 pain scale to a 0 to 10 pain scale for the purposes of pooling data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "The included participants were distributed quasi‐randomly into three groups."
Allocation concealment (selection bias)	High risk	Quasi‐random method of allocation likely precluded concealment of sequence to the single investigator who allocated the participants to treatment as it was predictable.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Participants were blinded to treatment allocation. A single investigator who performed all procedures was not blinded to treatment allocation.
Blinding of outcome assessment (detection bias) Self‐reported outcomes (e.g., pain, disability)	Low risk	Pain and disability was self‐assessed by participants who were unaware of their treatment allocation. Another orthopaedic surgeon not involved in the primary surgery performed the final follow‐up.
Blinding of outcome assessment (detection bias) Objective outcomes (e.g., radiographic outcomes)	High risk	Images were analysed by the (unblinded) orthopaedic surgeon who performed the procedures, as well as by a radiologist. It is not reported whether or not the radiologist was blinded to treatment allocation.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Data were unavailable for 7 participants (two deaths and five participants who refused follow‐up: treatment group not specified, however data were not reported for 1 participant in the vertebroplasty, 2 in the balloon kyphoplasty group and 4 in the shield kyphoplasty group).
Selective reporting (reporting bias)	Unclear risk	Trial not registered and trial protocol was not published. All outcomes listed in the methods are reported.
Other bias	Unclear risk	Participants in the vertebroplasty group were older on average than participants in other groups (71.3 versus 63.3 and 67.1 years in the balloon and shield vertebroplasty groups respectively). Participants in the kyphoplasty groups also appeared to have worse pain and disability scores at baseline compared to the vertebroplasty group (vertebroplasty: 78.2 and 68.2; balloon kyphoplasty: 90.0 and 77.0; and shield kyphoplasty 88.16 and 75.7, respectively). It is not clear if BioMedEs had any role in the study other than funding translation and copyediting.