Question:
In patients with chronic tendinopathy, what is the effectiveness of autologous blood injection (ABI)?
Data sources:
Studies were identified in MEDLINE with use of PubMed (to January 2010) and the Cochrane Central Register of Controlled Trials (to January 2010) and with use of the Google search engine.
Study selection and assessment:
Studies were included if they evaluated the use of ABI in tendinopathies of the elbow, patella, Achilles tendon, rotator cuff, or plantar fascia. Animal studies, conference abstracts, lesser-quality Internet publications, and human studies with no clinical outcomes were excluded. Levels of evidence were applied to the studies on the basis of the Centre for Evidence-Based Medicine criteria (www.cebm.net/index.aspx?o=1025).
Main outcome measures:
Primary outcome measures included improvement in pain assessed with visual analog scale (VAS) scores and Nirschl scores; return to normal activities, work, and sport; function assessed with the Tegner activity score, the Mayo Elbow Performance Score, and the Victorian Institute of Sport Assessment questionnaire; and tendon appearance on ultrasonography.
Main results:
15 studies (n = 526 patients) met the inclusion criteria: three randomized controlled trials (RCTs) (two on plantar fasciitis and one on Achilles tendinopathy), one cohort study on lateral and medial elbow epicondylitis, one systematic review on lateral elbow epicondylitis, nine case series (three on lateral elbow epicondylitis, one on medial elbow epicondylitis, one on lateral and medial elbow epicondylitis, one on Achilles tendinopathy, two on patellar tendinopathy, and one on plantar fasciitis), and one case report on plantar fasciitis. No study on rotator cuff tendinopathy met the inclusion criteria. The publication dates for the RCTs ranged from 2000 to 2007; the other studies’ dates ranged from 2003 to 2009. The RCTs showed no difference between ABI and control interventions (Table). The cohort study showed improved VAS and Mayo Elbow Performance Scores at six months among patients with lateral or medial elbow epicondylitis who received ABI. The systematic review showed improvement with autologous whole blood, platelet-rich plasma, polidocanol, and prolotherapy injections in patients with lateral elbow epicondylitis. Among the nine case series, improvement in pain scores was seen in two patellar studies, five elbow epicondylitis studies, and one plantar fasciitis study, and improvement in ultrasonic appearance was seen in one study of patellar tendinopathy and three studies of elbow epicondylitis. One study of Achilles tendinopathy showed an earlier return to gentle running.
Conclusion:
In patients with chronic tendinopathy, the evidence from small, mostly uncontrolled studies shows improvement in pain with autologous blood injections, but this is not borne out in trials.
NYU Hospital for Joint Diseases New York, NY
This comprehensive review by Kampa and Connell examines low and high-quality studies on the use of ABIs from whole blood injections or platelet-rich plasma for the treatment of chronic tendinopathies.
The resolution of chronic tendinopathies has consistently ranked among the most difficult and frustrating problems for patients and physicians. Too often treatment modalities provide outcomes that are little or no better than those achieved by simply decreasing the stress placed on an injured tendon and allowing the passage of time. The weaker studies in the review showed that patients with chronic tendinopathy treated with ABI had improvement in their pain symptoms, but past studies have consistently shown significant placebo effect for injection therapy. This issue is further complicated by the possibility that “peppering” or “needling” (a technique used in many of the studies in the review) the tissue is believed to have some therapeutic benefit on its own in the treatment of chronic tendinopathy.
Platelet-rich plasma may prove to be effective when such variables as timing of injection, number and frequency of injections, and concentration of platelets are examined, but the current research is not sufficient to direct its clinical use.
As long as platelet-rich plasma is in the news, injured athletes in particular will continue to request this treatment. On January 1, 2011, the World Anti-Doping Agency eased restrictions on platelet-rich plasma, citing that there was no evidence that the procedure enhanced performance (http://www.usada.org/prohibited-list/major-changes/). Perhaps the health-insurance companies that consistently refuse to reimburse for platelet-rich plasma are ahead of the curve regarding the question of efficacy. If the evidence continues to be less than compelling, we may need to remove this costly procedure from our treatment armamentarium.