Nilsson 2010

Methods	RCT Exp: Artelon TMC Spacer C: Trapeziectomy with tendon interposition (APL, ECRL or FCR)
Participants	Age (mean): Exp/C = 59/61 Gender (female/male): Exp/C = 61/9:33/4 Stage of OA (number of subjects): Exp/C = Eaton stage 1‐3 verified radiographically. Preoperative Eaton stage 4 were excluded.
Interventions	Surgery Exp/C: Exp A: Artelon TMC Spacer. Dosral approach used. Postopeartively 5 to 6 weeks of plaster fixation followed by mobilisation program. C: Trapeziectomy with interposition (22 cases with APL; 6 cases with ECRL; 9 cases with 9 cases). Same postoperative care as experimental group.
Outcomes	Pain: VAS was used, with 0 representing no pain, 10 maximum pain. Note: measurements were recorded at maximum loading during key pinch Physical Function: DASH Score Patient global assessment: Patient satisfaction was recorded from 1 (not at all satisfied) to 5 (very satisfied/very good) Range of motion: Radial and palmar abduction was measured in degrees with a goniometer Strength: grip strength was measured with a Jamar dynamometer, key and tripod pinch measured with a pinch gauge (North Coast Medical, Inc) Imaging: Joint space was measured (preoperatively and at 1 year) using plain x‐rays. Degree of OA was evaluated preoperatively. Complications: Joint swelling and pain.
Notes	Acknowledgements: Artelon manufacturer funded the trial Results reporting: Some results were reported using an ITT analysis while some were reported using a per‐protocol analysis. Data used for meta‐analysis was ITT data unless otherwise stated.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quotes: "according to a randomization list". Comment: unclear how the list was generated but appears to be randomised appropriately but using non‐patient related generation (i.e. not year of birth or date of procedure). Allocation was suggested to have prior to procedural anaesthesia: "After giving informed consent, the patients were randomized".
Allocation concealment (selection bias)	Unclear risk	Quote: "by using closed envelopes". Comment: unclear if the envelopes were sequential or chosen at random, and who stored the envelopes prior to them being used.
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	Quote: "the observers carrying out the follow‐up investigations were not informed about which surgical procedure the individual patient had undergone".
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: Reasons and allocation of participant attrition clearly identified but many more participants excluded at follow‐up from experimental group. Exp: 9 participants were excluded after surgery (6 reoperation, 1 serious illness, 2 did not attend follow‐up). C: 2 participants did not attend follow‐up.
Selective reporting (reporting bias)	Unclear risk	Comment: We did not identify a protocol.