Möckel 2004.

Methods	RCT stated Randomisation technique not stated Duration of study: 6 months
Participants	Inclusion criteria: PCL sufficient Exclusion criteria: other existing implants in lower extremities, factors influencing gait analysis, BMI > 35 Germany: 53 participants 45 female, 17 male, mean age 69 years
Interventions	Fixed: Natural Knee (Centerpulse) or Maxim (Biomet Merck) Mobile: PFC Sigma, rotating platform (DePuy) No patellar resurfacing All components cemented
Outcomes	ROM, KSS, gait analysis, alignment 3 months and 6 months follow‐up given Average and some range given
Notes	No funding stated No declarations of interest reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised allocation
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Participant blinding not described; surgeon not blinded
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Outcome assessor blinding not described
Incomplete outcome data (attrition bias) All outcomes	High risk	Drop‐out rate given: > 20% lost at 6 months; intention‐to‐treat analysis
Selective reporting (reporting bias)	Unclear risk	No protocol available
Other bias	Low risk	Homogeneity in participant groups on prognostic factors; co‐interventions described in sufficient detail