title: The short-term effect after a single injection of high-molecular-weight hyaluronic acid in patients with enthesopathies (lateral epicondylitis, patellar tendinopathy, insertional Achilles tendinopathy, and plantar fasciitis): a preliminary study.
abstract: BACKGROUND
  Hyaluronic acid (HA) with a high molecular weight of 2700 kDa is approved in Japan to treat osteoarthritis of the knee, periarthritis scapulohumeralis, and knee pain associated with rheumatoid arthritis. The purpose of this preliminary study was to investigate the short-term efficacy, safety, and injectable volume of HA in the treatment of enthesopathies.
  
  
  METHODS
  A total of 61 patients (16 with lateral epicondylitis, 14 with patellar tendinopathy, 15 with insertional Achilles tendinopathy, and 16 with plantar fasciitis) were each administered a single injection of HA (up to 2.5 ml). Efficacy and safety were assessed by comparing the visual analog scale (VAS) for pain and local symptoms before injection (baseline) and at 1 week after injection. We also investigated the injectable volume by means of the difference in syringe weight before and after injection and by the judgment of the administering investigator.
  
  
  RESULTS
  The injection of HA resulted in a change in VAS (mean ± SD) of -2.20 ± 2.26 cm for the four sites overall and -2.55 ± 2.43 cm for lateral epicondylitis, -2.01 ± 2.16 cm for patellar tendinopathy, -1.80 ± 1.91 cm for insertional Achilles tendinopathy, and -2.38 ± 2.61 cm for plantar fasciitis. The injection of HA also improved local symptoms in each site. It was also determined that 2.5 ml of HA can be injected in each of the four sites.
  
  
  CONCLUSIONS
  A single injection of HA resulted in similar improvements of pain in each of the four enthesopathies (lateral epicondylitis, patellar tendinopathy, insertional Achilles tendinopathy, and plantar fasciitis). These results suggest that HA could be clinically effective in the treatment of enthesopathies.
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan, kumakumat@aol.com.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Kumai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Muneta
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tsuchiya
authors.forename: Masaharu
authors.initials: M
authors.lastname: Shiraishi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Ishizaki
authors.forename: Kazuya
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Norihiro
authors.initials: N
authors.lastname: Samoto
authors.forename: Shinji
authors.initials: S
authors.lastname: Isomoto
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takakura
mesh_terms: D000125:Achilles Tendon; D000328:Adult; D036981:Fasciitis, Plantar / Q000188:drug therapy*; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D007267:Injections; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010329:Patella; D011446:Prospective Studies; D052256:Tendinopathy / Q000188:drug therapy*; D013716:Tennis Elbow / Q000188:drug therapy*; D013997:Time Factors; D055815:Young Adult
chemical_list: D006820:Hyaluronic Acid