Field 2007

Methods	RCT Exp: Trapeziectomy with LRTI (half FCR) C: Trapeziectomy
Participants	Age (mean): 55 Gender (female/male): Exp/C = 28:5/28:4 Stage of OA (number): Exp/C = 15 gr III, 18 gr IV/14 gr III, 18 gr IV
Interventions	Surgery Exp/C: Exp: Trapeziectomy with LRTI (using half of FCR). All patients immobilised in Bennett's type cast for 4 weeks, then mobilised for further 4 to 6 weeks. C: Trapeziectomy.
Outcomes	Pain: Pain was measured on a VAS. Physical function: Not reported. Patient global assessment: Not reported. Range of motion: Palmar and radial abduction was measured in degrees and first web space span was measured in cm. Strength: Grip and key and tip pinch strength were measured in kg. Trapeziometacarpal joint imaging: Mean scapho‐metacarpal distance (mm) was measured pre‐operatively and at 12 months postoperatively. Adverse events: complications including superficial wound infections, radial nerve irritation, adherent scars and CRPS were reported.
Notes	Follow‐up at 3, 6 and 12 months. We contacted a trial author who provided mean and SD values for range of motion, pain and strength and information on blinding.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: Computer randomised numbers.
Allocation concealment (selection bias)	Unclear risk	Comment: Sealed envelopes, unclear if they were opaque, sequentially numbered or kept by someone other than the surgeon until needed or when allocation occurred.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: Unclear if participants were informed of surgery performed prior to final review.
Blinding of outcome assessment (detection bias) Subjective outcomes (patient reported)	Unclear risk	Comment: Unclear if participants were informed of surgery performed prior to final review.
Blinding of outcome assessment (detection bias) Objective outcomes	Low risk	Comment: Assessors appropriately blinded (personal communication).
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: All patients attended for 12‐month follow‐up.
Selective reporting (reporting bias)	Unclear risk	Comment: We identified a protocol (http://www.controlled‐trials.com/isrctn/pf/05154295) which provided limited information on outcomes.