Dalsgaard 1986.

Study characteristics
Methods	Quasi‐randomised; parallel design Review comparison group: Ender versus SSP
Participants	Total number of randomised participants: 101 Inclusion criteria: pertrochanteric fractures Exclusion criteria: not reported Setting: single centre, hospital, Denmark Baseline characteristics Intervention group 1 (Ender) Age, average (range): 79 (47 to 97) years Fracture classification, stable/unstable, n: 21/36 Intervention group 2 (SSP) Age, average (range): 80 (49 to 93) years Fracture classification, stable/unstable, n: 17/27 Note: study provided no baseline characteristics
Interventions	General details: prophylactic antibiotics were not used. 30% of participants were operated on by senior house officers, and remaining were operated on by consultants and senior registrars; regular clinical follow‐up for minimum of 6 months Intervention group 1: Ender nails (manufacturer not reported) Number randomised to group = 57; losses = not reported, number analysed = 57 Intervention group 2: Sliding nail plate (manufacturer not reported) Number randomised to group = 44; losses = not reported, number analysed = 48
Outcomes	Outcomes measured/reported by study authors: unplanned return to theatre (available at six months); operations time; distal slipping; deep infection; shortening of the leg; walking ability Outcomes relevant to the review: unplanned return to theatre (reported at 6 months); mortality (6 months)
Notes	Funding/sponsor/declarations of interest: no details on funding or conflict of interest are provided Study dates: not reported Note:  study reported in Danish. We used an English translation of this paper by SU Sjølin.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Randomised using date of birth
Allocation concealment (selection bias)	Unclear risk	Method of allocation not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	It is not possible to blind surgeons to treatment groups.
Other performance bias: surgeon experience of both implants	Unclear risk	Study authors do not report the experience and skills of the surgeons and we could not be certain whether surgeons were equally experienced with both types of implants.
Blinding of outcome assessment: unplanned return to theatre (detection bias)	High risk	It is not possible to blind surgeons to treatment groups. We judged that knowledge of the type of intervention could influence judgments made by surgeons when assessing this subjective outcome.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses are reported.
Selective reporting (reporting bias)	Unclear risk	Study authors did not report pre‐published protocol or clinical trial registration. It is not feasible to effectively assess risk of selective reporting bias without these documents.
Other bias	Low risk	We identified no other sources of bias.