Heikkilä 2011.

Study characteristics
Methods	Single‐centre RCT
Participants	Country of study: Finland Sample size: 25 participants Age: mean 54 years, range 25 to 82 years Sex: 12 males (48%) and 13 females Fracture type: closed depressed unilateral tibial comminuted plateau fracture (AO classification 41 B2 and B3). Injury severity: injury severity score not reported; unknown number resulted from traffic accidents. Inclusion criteria: all patients were healthy, without systemic diseases and with normal bone structure. Joint line depression of more than 3 mm was indication for operative treatment. Exclusion criteria: not formally defined.
Interventions	Surgical procedure: the lateral condyle was exposed through an anterolateral posteriorly curved incision. Intact lateral meniscus and ACL were observed in all knees. Lateral meniscus was detached at its tibial insertion to visualise the joint line. After lateral cortical fenestration, the articular surface was elevated under direct visual control. The fracture was then temporarily fixed using K‐wires, and the elevation of articular surface was confirmed by preoperative plain films. Bone filler 1: synthetic bone graft group (n = 14); granules were packed manually to quantitatively fill the defect caused by the fracture and the elevation. Bone filler 2: autograft group (n = 11); defect was filled with autologous bone harvested from anterior iliac crest. The iliac crest was exposed using an incision along the superior iliac crest, which was chiselled temporarily aside, and medial lamina and corticocancellous bone chips were used as filler material.
Outcomes	Follow‐up: clinical evaluation at 3 and 12 months postoperatively, and radiological evaluation immediately postoperatively then at 3 and 12 months. An 11‐year follow‐up of 15 participants is also reported. Outcome measures: lower limb function, KOOS at 11 years, complications, range of knee motion, knee stability, blood loss, articular depression, presence of radiologically detected osteoarthritis
Notes	The demographics were not specified, but study authors reported no statistical differences with regard to the fracture anatomy, surface area of the fracture or the degree of depression on condyle surface between groups. Source of funding: none reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The randomisation was reported as being "performed using closed envelopes". The method of sequence generation was not reported.
Allocation concealment (selection bias)	Unclear risk	The randomisation was reported as being "performed using closed envelopes". Insufficient description of methods to safeguard allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No mention of blinding. Given the contrast in the interventions, it is unlikely that blinding was done.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No mention of blinding.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	The abstract of the long‐term report of this trial refers to the recruitment of 29 patients, but the main report only provides results for 25. Otherwise there was no reported loss to follow‐up in the main report. The loss to follow‐up was unbalanced at 11 years' follow‐up. Incomplete outcome data.
Selective reporting (reporting bias)	High risk	All outcome measurements outlined in the methods section were reported in the results section, but numerical data were often not available. No published protocol or trial registration number available.
Other bias	Unclear risk	Baseline balance claimed, but data were not provided, and there was a 7‐year difference in the mean ages (57 years bioactive glass versus 50 years autograft). No other risk of bias identified.