Background: Although there has been a recent increase in interest regarding injectable therapy for noninsertional Achilles tendinosis, there are currently no clear treatment guidelines for managing patients with this condition. The objective of this study was (1) to conduct a systematic review of clinical outcomes following injectable therapy of noninsertional Achilles tendinosis, (2) to identify patient-specific factors that are prognostic of treatment outcomes, (3) to provide treatment recommendations based on the best available literature, and (4) to identify knowledge deficits that require further investigation.
Methods: We searched MEDLINE (1948 to March week 1 2012) and EMBASE (1980 to 2012 week 9) for clinical studies evaluating the efficacy of injectable therapies for noninsertional Achilles tendinosis. Specifically, we included randomized controlled trials and cohort studies with a comparative control group. Data abstraction was performed by 2 independent reviewers. The Oxford Level of Evidence Guidelines and GRADE recommendations were used to rate the quality of evidence and to make treatment recommendations.
Results: Nine studies fit the inclusion criteria for our review, constituting 312 Achilles tendons at final follow-up. The interventions of interest included platelet-rich plasma (n = 54), autologous blood injection (n = 40), sclerosing agents (n = 72), protease inhibitors (n = 26), hemodialysate (n = 60), corticosteroids (n = 52), and prolotherapy (n = 20). Only 1 study met the criteria for a high-quality randomized controlled trial. All of the studies were designated as having a low quality of evidence. While some studies showed statistically significant effects of the treatment modalities, often studies revealed that certain injectables were no better than a placebo.
Conclusions: The literature surrounding injectable treatments for noninsertional Achilles tendinosis has variable results with conflicting methodologies and inconclusive evidence concerning indications for treatment and the mechanism of their effects on chronically degenerated tendons. Prospective, randomized studies are necessary in the future to guide Achilles tendinosis treatment recommendations using injectable therapies.
Level of evidence: Level II, systematic review.
Keywords: Achilles tendon; injections; midsubstance; tendinopathy; tendinosis.