Sun 2014.

Methods	Randomised controlled trial, blinded, parallel group. Follow‐up of 6 months, at baseline, 2 weeks, 1 month, 3 months and 6 months.
Participants	75 participants, unilateral ankle pain for at least 6 months; Age between 20 and 85. 37 Hyalgan group (mean age 50.6 (SD 10.3), 14 female, 23 male) and 38 in Botuline group (mean age 49.5 (SD 10.9), 15 female, 23 male) At baseline a AOS score of > 30 and < 90 was mandatory. Ankle OA based on an X ray within 6 months of baseline and equivalent with Kellgren Lawrence grade II
Interventions	Single injection of 2 ml Hyalgan intra‐articular versus Botuline, combined with 12 session (3 weekly for 4 weeks of physical therapy (PT)).
Outcomes	Primary outcome total AOS. Pain (AOS, AOFAS, VAS, Rescue Medication), Safety (registering amount of adverse events), Physical function (AOS, AOFAS, Single Leg stance test (SLS), Timed up and go Test (TUG)), analgesic consumption, satisfaction.
Notes	Two totally different injections are compared, and one group even had a physical therapy program added. Unclear why they compared these two treatments, as it made more sense to compare without physical therapy. The study was supported by a grant of VGHKS100‐061 (an academic research fund from the hospital's medical research council).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Block randomisation: groups of 4.
Allocation concealment (selection bias)	Low risk	Block randomisation: groups of 4.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Injection compared to injection followed by PT makes it likely that the participants communicated which treatment they underwent. Impossible to blind participants to the therapy they underwent.
Blinding of outcome assessment (detection bias) All outcomes	High risk	The secondary outcomes like SLS might be affected by knowing which therapy the participant underwent.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data.
Selective reporting (reporting bias)	Low risk	Results show same outcomes as described in the Method section.
Other bias	Unclear risk	Unclear what the effect is of two completely different treatment options where one injection + exercise therapy is compared to another injection.