Schepull 2010.

Methods	Randomised controlled trial: randomisation occurred as blocks of 6 participants, assignment kept in sealed envelopes. Allocation concealment was kept until the operative time. Participants and outcome assessors were blind to the intervention. Participants were followed for 1 year Trial conducted: Linköping University, Linköping, Sweden; recruitment: September 2007‐April 2008
Participants	Participants: 30 undergoing open repair of acute achilles tendon rupture Inclusion criteria: participants aged 18‐60 years, with an acute (< 3 days) rupture of Achilles tendon Exclusion criteria: diabetes mellitus; a history of cancer or lung or heart diseases; or diseases that could compromise the locomotor system Age: PRT group mean (range): 39.8 years (6.2) No PRT mean (range): 39.4 years (8.3) Gender: PRT group (number of men:women): 13:3 No PRT (number of men:women): 11:3 Sports activity: All participants were recreational athletes injured during sports or sports‐related activities
Interventions	All participants underwent open repair of acute Achilles tendon injuries, with implantation of tantalum beads to aid in image analyses PRT (number of participants = 16): 450 mL blood derived a mean volume of 21 mL PRP. PRP was prepared and stored, with constant rotation, up to 20 hours before use. Platelet viability was assessed, and found to have been maintained in all cases PRT preparation: no dedicated kit. Authors stated that they utilised a credited procedure (Europe 2007) Quantification of platelet concentrates after preparation: 3673 (SD 1051) x 109 platelets per mL No PRT (number of participants = 14): no platelet‐rich therapy controls Co‐interventions: same rehabilitation protocol
Outcomes	Tendon strain per load: distance between the tantalum beads (roentgen stereophotogrammetric analysis (RSA)) while participants resisted different dorsal flexion moment over the ankle joint Estimate of elasticity modulus (using callus dimensions from computed tomography) Functional outcome: heel‐raise index and Achilles tendon Total Rupture Score
Other quality issues	Sample size: the authors did not calculate the sample size Validation of PRT: the exact composition of the PRP is unknown
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation	Low risk	Used permuted blocks of 6 participants
Allocation concealment	Low risk	Used sequentially‐numbered, opaque and sealed envelopes
Blinding All outcomes	Low risk	The participants and outcome assessors were blinded to the treatment
Incomplete outcome data addressed All outcomes	High risk	Missing outcome data were not balanced in numbers across intervention groups; more participants in the PRP group were lost to follow‐up (4/16 (25%) PRP versus 0/14 (0%) control)
Free of selective reporting	Unclear risk	The study protocol is not available, but all expected outcomes were assessed
Free of other bias	Low risk	The study appears to be free of other bias