A Randomized Controlled Single-Blind Study Demonstrating Superiority of Amniotic Suspension Allograft Injection Over Hyaluronic Acid and Saline Control for Modification of Knee Osteoarthritis Symptoms

J Knee Surg. 2019 Nov;32(11):1143-1154. doi: 10.1055/s-0039-1696672. Epub 2019 Sep 18.


Placental-derived tissues are a known source of anti-inflammatory and immune modulating factors. Published pilot data on amniotic suspension allograft (ASA) for the treatment of osteoarthritis (OA) demonstrated safety and trends for improved pain and function. A multicenter randomized controlled trial was designed to evaluate the efficacy of symptom modulation with ASA compared with saline and hyaluronic acid (HA) in subjects with knee OA. A total of 200 subjects were randomized 1:1:1 to ASA, HA, or saline, with subjects blinded to their allocation. Changes from baseline of patient-reported outcomes (PROs)-EQ-5D-5L, Knee Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS), Tegner, and Single Assessment Numerical Evaluation (SANE)-were compared between groups. Patients reporting unacceptable pain at 3 months were considered treatment failures and withdrawn from the study. Statistical analysis was completed by comparing changes in PROs from baseline to 3 and 6 months for all groups. Comparison of demographics between treatment groups showed no significant differences between groups. Patients reporting unacceptable pain at 3 months in each group were ASA (13.2%), HA (68.8%), and saline (75%). Patients receiving ASA demonstrated significantly greater improvements from baseline for overall pain (VAS), KOOS pain, and KOOS-activities of daily living scores compared with those in the HA group (3 months) and both groups (6 months). ASA patients had significantly greater improvements in KOOS symptom scores compared with HA and saline at 3 and 6 months, respectively. OMERACT-OARSI responder rates for ASA, HA, and saline groups were 69.1, 39.1, and 42.6%, respectively (p = 0.0007). Subjects receiving ASA treatment showed greater improvements in PROs and fewer patients reported unacceptable pain compared with HA and saline. The evidence presented in this Level I Randomized Controlled Trial suggests that ASA injection is an effective treatment for the nonoperative management of symptomatic knee OA.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Activities of Daily Living
  • Adult
  • Aged
  • Amniotic Fluid*
  • Female
  • Humans
  • Hyaluronic Acid / administration & dosage*
  • Injections, Intra-Articular
  • Male
  • Middle Aged
  • Osteoarthritis, Knee / complications
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / therapy*
  • Pain Measurement
  • Single-Blind Method
  • Transplantation, Homologous
  • Treatment Outcome
  • Viscosupplements / administration & dosage*
  • Visual Analog Scale


  • Viscosupplements
  • Hyaluronic Acid