Toksvig‐Larsen 1998.

Methods	RCT, sealed envelopes. The primary outcome measure in this study was RSA. For the secondary outcome measure, i.e. the clinical data, the assessor was not blinded.
Participants	Inclusion: Osteoarthrosis: 27 participants (28 knees). No exclusion criteria were specified. Average age: 71 years. Average body weight: 79 kg. Five participants were lost.
Interventions	Randomized tibial component fixation: Cemented or uncemented without hydroxyapatite. The femoral component was inserted without cement, and the patella was not resurfaced. The cement was applied to the horizontal cut surface but not around the stem. All knees received a porous‐coated anatomic total knee prosthesis (PCA Universal; Howmedica) with a porous‐coated anatomic modular cruciform stem tibial component. The cementing technique included vacuum‐mixing of the cement, lavage, and pressurization.
Outcomes	RSA (MTPM, subsidence and inducible displacement), HKA, Hospital for Special Surgery, extension, flexion, and walking distance.
Notes	Duration of follow‐up: 2 years. The prostheses that was inserted with cement subsided 0.0 ± 0.1 millimeter, and the prostheses that was inserted without cement subsided 0.5 ± 0.1 millimeter at the two year follow‐up evaluation (P = 0.008). Some data were obtained by personal communication (Toksvig‐Larsen 1998).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	In a personal communication (Toksvig‐Larsen 1998), the author stated: "All knees were randomized, patients with bilateral surgery were operated with an interval of more than 3 months."
Allocation concealment (selection bias)	Low risk	Personal communication (Toksvig‐Larsen 1998) ‐ The allocation was performed using sealed envelopes.
Was the patient blinded?	Unclear risk	This item was not mentioned in the trial report.
Was the surgeon blinded?	High risk	It is impossible to blind the surgeon to prosthesis fixation.
Was the outcome assessor blinded?	Unclear risk	This item was not mentioned in the trial report.
Was the withdrawal/drop‐out rate described, acceptable (<20%), and comparable in both groups?	High risk	The withdrawal/drop‐out rate was described, was not acceptable and was not comparable between the groups.
Selective reporting (reporting bias)	Low risk	The study protocol is available, and all of the study’s prespecified (primary and secondary) outcomes that were of interest in the review were reported in the prespecified manner.