Nakamura 2001.

Methods	RCT; randomisation procedure not described
Participants	Medial osteoarthritis of the knee
Interventions	I: HCO (n = 23) C: dome osteotomy (DMO; n = 23) Follow‐up: 12 months No dropout
Outcomes	FTA Patellar height Inclination angle of tibial plateau Tibial condylar offset
Notes	Quote: "No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "They were randomly allocated to either a DMO or [an] HCO"
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	High risk	Not possible
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not possible
Blinding of outcome assessment (detection bias) All outcomes	High risk	Relevant leg not covered to conceal the operative technique
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts mentioned
Selective reporting (reporting bias)	Unclear risk	No study protocol available
Other bias	Low risk	No issue