Platelet-rich Plasma or Autologous Blood Do Not Reduce Pain or Improve Function in Patients with Lateral Epicondylitis: A Randomized Controlled Trial

Abstract

Background Platelet-rich plasma (PRP) and autologous blood are commonly used therapies for lateral epicondylitis, but the evidence from randomized, placebo-controlled trials is conflicting. Thus, it is still unclear if patients benefit from these treatments. Questions/purposes In the setting of a randomized, placebo-controlled trial, we compared PRP, autologous blood, and saline injections in the treatment of lateral epicondylitis with respect to: (1) VAS pain scores, and (2) functional outcomes (DASH score and grip strength) 1 year after treatment. Methods We performed a parallel-group, randomized, controlled participant- and assessor-blinded study including adults with clinically diagnosed lateral epicondylitis. We defined lateral epicondylitis as pain in the lateral humeral epicondyle area exacerbated during resisted wrist extension and epicondyle compression. The participants were recruited from a secondary referral center, after not responding to initial nonoperative treatment. Patients with other concomitant upper-limb symptoms and surgical treatment of the elbow were excluded. Randomization sequence was generated with computer software and concealed from the investigators. We randomized 119 participants to receive an injection of PRP, autologous blood, or saline (1:1:1) in the proximal insertion of the extensor carpi radialis brevis muscle; 40 participants received PRP, 40 received autologous blood, and 39 received a saline injection. To prepare the PRP, we collected venous blood with a syringe kit followed by centrifugation, whereas autologous blood group received unprepared blood injection. Two unblinded investigators gave injections while the participant was unable to see the injection. There was no formal postinjection rehabilitation protocol and the use of NSAIDs was similar between different treatment arms. Follow-up visits were at 4, 8, 12, 26, and 52 weeks after the injection. The primary outcome measure was improvement in pain, measured with VAS scale (without specification as to whether the pain was activity related or at rest; range 0-10; a higher score indicates worse pain; the minimum clinically important difference [MCID] on the 10-cm scale was 1.5 cm), from baseline to 52 weeks. The secondary outcomes were the DASH score (range 0-100; a higher indicates a poorer outcome, and the MCID was 10.2 points) and grip strength. All patients were included in the analyses, and analyses were performed using the intention-to-treat principle. There was no crossover between treatment groups. At 52 weeks, nearly all (95% [38 of 40]) participants in autologous blood group were available for analysis whereas 78% (31 of 40) and 82% (32 of 39) were available in PRP and saline groups. This study was registered at ClinicalTrials.gov and funded by the local hospital district. With 40 patients in each group, we had 80% power to detect a clinically important improvement in pain (1.5 cm on the 10-cm VAS pain scale). Results There were no clinically important differences in the mean VAS pain or DASH scores among the groups at any timepoint. At 52 weeks, the mean difference in the VAS score for pain was -0.2 (95% CI -1.5 to 1.1; p = 0.75) for PRP versus saline and 0.5 (95% CI -0.7 to 1.7; p = 0.40) for autologous blood versus saline. The corresponding mean differences in the DASH score were 0.0 (95% CI -9.2 to 9.2; p > 0.99) and 7.7 (95% CI -1.3 to 16.7; p = 0.09) and those for grip strength were 1.4 kg (95% CI -3.3 to 6.1; p = 0.56) and -0.2 kg (95% CI -5.0 to 4.5; p = 0.92). No complications occurred because of the injections. Conclusions PRP or autologous blood injections did not improve pain or function at 1 year of follow-up in people with lateral epicondylitis compared with those who were given a saline injection. However, because the 95% CIs did not exclude the MCID in VAS scores for autologous blood versus saline at 52 weeks, it is possible that a larger study could identify a between-group difference that we missed, but the effect size of that difference (based on our findings), even if present, is likely still to be small. Until or unless future randomized trials convincingly show a benefit either to PRP or autologous blood injections, we recommend against their use in patients with lateral epicondylitis. Level of Evidence Level II, therapeutic study.

Standardized Tendon Fenestration with Injection of Autologous Blood for Treatment of Lateral Epicondylitis

“…14 The therapeutic effect of autologous blood as well as PRP was debated by different randomized controlled trials, who found no different outcome after autologous blood and PRP versus saline injections. 15,16 Uygur et al investigated percutaneous dry needling or fenestration, promoting beneficial bleeding into new channels created through mucoid degeneration as a potential treatment. The mechanical disruption may initiate a healing response in the tendon.…”

Comparative analysis of leucocyte poor vs leucocyte rich platelet-rich plasma in the management of lateral epicondylitis: Systematic review & meta-analysis of randomised controlled trials

“…While 5/ 26 did not mentioned any data on the funding sources, rest 11/26 were non-funded studies. On further analysing the source of funding of those 10 studies, it was noted that 3 studies 27,28,31 received institutional research funding, and remaining 7 studies were funded directly or indirectly by commercial agents. Of the commercial sponsors we noted that Biomet Biologics Inc. (Warsaw, Indiana) funded 5 of the included studies involving LR-PRP 21,24,3,32,41 while 2 studies 30,34 involving LP-PRP was supported by Arthrex ®, Naples, FL, USA who were the manufactures of the extraction kits used in these trials.…”

“…DASH score DASH score was reported in 11 of the included studies, 21,22,25,27,28,31,32,34,36,40,41 of which six studies 21,27,28,31,36,41 utilized LP-PRP involving 424 patients while rest 5 studies utilized LR-PRP involving 345 patients. There was a significant heterogeneity observed between the included studies.…”

Editorial Commentary: Elbow Lateral Epicondylitis Treatment Using Platelet-Rich Plasma

“…[11][12][13][14] Other studies, however, dispute the efficacy of PRP injections for the treatment of chronic lateral epicondylitis. 11,15,16 In their systematic review entitled "To Improve Pain and Function, Platelet-Rich Plasma Injections May Be an Alternative to Surgery for Treating Lateral Epicondylitis: A Systematic Review," Hardy, Tori, Fuchs, Larson, Brand, and Monroe 17 seek to determine whether PRP injections offer patients comparable outcomes versus surgical intervention for lateral epicondylitis. After a search of various databases, more than 7,000 articles were identified, but only 3 articles met the authors' inclusion criteria (1 Level II and 2 Level III studies).…”

“…Indeed, PRP injections have shown efficacy in some previous studies, 3,6,7 but not all studies have made similar determinations. [14][15][16]20 Likewise, previously published systematic reviews and meta-analyses comparing PRP use with other interventions for the treatment of lateral epicondylitis have reached variable conclusions. [20][21][22][23][24][25] Hardy et al also commented on the low complication rate after PRP injections.…”