Hanschen 2014.

Study characteristics
Methods	Prospective RCT
Participants	Setting: 4 university trauma centres in South Germany Size: 27 participants; 12 to LISS group, 15 to NCB group) Recruitment period: 2008–2011 Baseline characteristics: 8 males, 19 females; mean age 63.9 years in LISS group, 73.1 years in NCB group; fractures included were AO/OTA type A (11 fractures), B (3 fractures), C (7 fractures); 6 periprosthetic fractures and 5 open fractures. Inclusion criteria: fractures of distal femur; all type 33‐A (11), 33‐B (3) and 33‐C (7) fractures were included, as well as periprosthetic fractures of the distal femur. Exclusion criteria: none listed
Interventions	Either a standardised antero‐lateral or additional medial approach used to reduce fragments. Temporary fixation achieved using K‐wires, screws or clamps. Locking plate then applied with temporary K‐wire fixation. Plate then fixed. Participants randomised to: LISS; NCB. All participants received prophylactic antibiotics. Physiotherapy commenced postoperatively with range of motion exercises. Participants instructed to be non‐weight‐bearing for 6–8 weeks.
Outcomes	Schedule: 1 and 6 weeks; 3, 6, 9 and 12 months Outcomes: mean operating time, mean intraoperative x‐ray time, mean skin cut length, need for skin cut extension, mean size of implant, intraoperative arthroscopy, surgical complication (wound infection, peroneal lesions, compartment syndrome), range of motion, cruciate ligament stability, collateral ligament stability, VAS, OKS, Rasmussen score, Lysholm score, Tegner score
Notes	Funding/sponsor/declarations of interest: study author instructor for a course provided by 1 of the companies producing implants. No information provided on funding or sponsors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised according to a randomisation plan (Randlist). To ensure balanced randomisation in all 4 trauma centres, randomisation performed blockwise.
Allocation concealment (selection bias)	Unclear risk	No mention of allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Nature of interventions meant that the operating surgeons were not blinded. No details relating to participant blinding. All surgeons described as experienced.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No mention of blinding.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Numbers of participants with data for each variable not reported, though no reporting of missing data.
Selective reporting (reporting bias)	Unclear risk	No study prospectively published protocol or registration exists.
Other bias	Low risk	We identified no other sources of bias.