Objective To determine whether an injection of platelet rich plasma improves outcomes after acute Achilles tendon rupture.
Design Randomised, placebo controlled, two arm, parallel group, participant and assessor masked, superiority trial.
Setting Secondary care trauma units across 19 hospitals in the United Kingdom’s health service.
Participants Recruitment commenced in July 2015 and follow-up was completed in March 2018. 230 adults aged 18 years and over were included, with acute Achilles tendon rupture presenting within 12 days of injury and managed with non-surgical treatment. Exclusions were injury at the insertion or musculotendinous junction, major leg injury or deformity, diabetes mellitus, platelet or haematological disorder, systemic corticosteroids, anticoagulation treatment, and other contraindicating conditions.
Interventions Participants were randomised 1:1 to platelet rich plasma (n=114) or placebo (dry needle; n=116) injection. All participants received standard rehabilitation care (ankle immobilisation followed by physiotherapy).
Main outcomes and measures Primary outcome was muscle tendon function at 24 weeks, measured objectively with the limb symmetry index (injured/uninjured×100) in maximal work done during the heel rise endurance test (an instrumented measure of repeated single leg heel rises until fatigue). Secondary outcomes included patient reported function (Achilles tendon rupture score), quality of life (short form 12 version 2®), pain (visual analogue scale), goal attainment (patient specific functional scale), and adverse events. A central laboratory analysed the quality and content of platelet rich plasma. Analyses were by modified intention to treat.
Results Participants were 46 years old on average, and 57 (25%) of 230 were female. At 24 weeks, 202 (88%) participants completed the heel rise endurance test and 216 (94%) the patient reported outcomes. The platelet rich plasma was of good quality, with expected growth factor content. No difference was detected in muscle tendon function between participants receiving platelet rich plasma injections and those receiving placebo injections (limb symmetry index, mean 34.7% (standard deviation 17.7%) v 38.5% (22.8%); adjusted mean difference −3.9% (95% confidence interval −10.5% to 2.7%)) or in any secondary outcomes or adverse event rates. Complier average causal effect analyses gave similar findings.
Conclusions There is no evidence to indicate that injections of platelet rich plasma can improve objective muscle tendon function, patient reported function, or quality of life after acute Achilles tendon rupture compared with placebo, or that they offer any patient benefit.
Trial registration ISRCTN54992179.

目的确定注射富含血小板的血浆是否能改善急性跟腱断裂后的预后。
设计随机，安慰剂对照，两臂，平行组，参与者和评估者掩盖的优越性试验。
设置在英国的卫生服务，全国19家医院二级保健创伤单位。
参加者招募工作于2015年7月开始，随访于2018年3月完成。其中包括230名18岁及以上的成年人，急性跟腱断裂在受伤后12天内出现，并接受了非手术治疗。排除因素包括插入处或肌腱连接处的损伤，大腿损伤或畸形，糖尿病，血小板或血液疾病，全身性糖皮质激素，抗凝治疗以及其他禁忌症。
干预措施参与者以1：1的比例随机分配至富含血小板的血浆（n = 114）或安慰剂（干针； n = 116）注射。所有参与者均接受了标准的康复护理（固定踝关节，然后进行理疗）。
主要成果和措施主要结局是24周时的肌腱功能，以脚后跟耐力测试过程中进行的最大工作（用仪器测量单腿脚后跟反复抬起直至疲劳）的肢体对称性指标（受伤/未受伤×100）客观测量。次要结果包括患者报告的功能（跟腱断裂评分），生活质量（简短表格12版本2®），疼痛（视觉模拟评分），目标达成情况（患者特定的功能评分）和不良事件。中央实验室分析了富含血小板血浆的质量和含量。分析是通过修改意向进行的。
结果参与者的平均年龄为46岁，其中230位女性中有57位（25％）是女性。在第24周，有202名（88％）的参与者完成了脚跟抬起耐力测试，并且有216名（94％）的患者报告了结局。富含血小板的血浆质量良好，具有预期的生长因子含量。接受富血小板血浆注射的参与者与接受安慰剂注射的参与者之间的肌腱功能未检测到差异（肢体对称指数，平均34.7％（标准偏差17.7％）v 38.5％（22.8％）；调整后的平均差异为-3.9％（95） ％置信区间-10.5％到2.7％）或任何次要结果或不良事件发生率。编制者的平均因果效应分析得出了相似的发现。
结论没有证据表明与安慰剂相比，注射富含血小板的血浆可以改善急性跟腱断裂后的客观肌腱功能，患者报告的功能或生活质量，或者它们可以为患者带来任何好处。
试用注册ISRCTN54992179。