Smejkal 2011.

Study characteristics
Methods	Method of randomisation: computer‐generated block randomisation with sealed envelopes Assessor blinding: no mention in the paper Loss to follow‐up: 4 lost to follow‐up and 2 died of breast cancer during the study period
Participants	University Hospital in Hradec Králové, Czech Republic Period of study recruitment: January 2006 to January 2010 61 participants with AO type A2, A3, B1 and C1 (2‐part and 3‐part) proximal humeral fractures aged between 18 and 80 years able to give informed consent Exclusion criteria: open fracture, associated injury (Abbreviated Injury Scale (AIS) > 2), open growth plates, or patient's health would limit the extent of surgery Of 55: 45 females, 10 males; mean age 61 years, range 21 to 81 years
Interventions	Interventions started 0 to 24 days after injury. 1. Open reduction and internal fixation group: consisted of participants undergoing open reduction with angle‐stable osteosynthesis using a PHILOS plate (Synthes, Switzerland). 2. Minimally invasive group: Zifko method of minimally invasive osteosynthesis with intramedullary K‐wire (Kirschner wire) insertion (distally inserted) – figure in article shows 8 wires inserted into humeral head along medullary canal. Assigned: number in each group not known (total 61) Completed: 28/27
Outcomes	Length of follow‐up: mean 2 years Days to operation Constant score (relative to healthy limb) Time to recover normal upper‐limb function Complications Time to radiographically‐assessed recovery Anatomical position X‐ray exposure Length of operation Length of hospital stay
Funding and conflict of interest statements	There was no statement on funding. There was no statement on conflicts of interest.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“The patients were randomised to the groups by a computer programme which facilitates the maintenance of homogeneity of the groups compared.” Web‐based translation implied use of random numbers and permuted blocks so as to get similar numbers on each group. Produced independently by a statistical company.
Allocation concealment (selection bias)	Low risk	The sealed envelopes were created by a professional statistical company (Pharm test s. r. o., Hradec Králové): in accordance with the randomisation sheet, each numbered envelope had sealed inside either "zifko" or "LCP". The sealed envelopes were opened sequentially.
Blinding (performance bias and detection bias) Functional outcomes, pain, clinical outcomes, complications	High risk	Not possible to blind participant/providers. No mention of outcome assessment
Blinding (performance bias and detection bias) Death, reoperation	Unclear risk	May not affect assessment
Incomplete outcome data (attrition bias) Functional outcomes, pain, clinical outcomes, complications	High risk	Incomplete data (and group of 6 excluded participants not noted)
Incomplete outcome data (attrition bias) Death, reoperation	High risk	Incomplete data (and group of 2 deaths not stated)
Selective reporting (reporting bias)	Unclear risk	No protocol
Balance in baseline characteristics?	Unclear risk	Aside from age – no details or confirmation of this
Free from performance bias?	Unclear risk	No details – including of surgeon’s experience