Summary
Cryogenically preserved Amniotic Suspension Allograft hip injection appears to be a safe, effective treatment for moderate hip osteoarthritis, with sustained clinical benefit at one year post-injection in this pilot study.
Abstract
Background
/ Purpose: There is increasing interest in strategies for management of patients with moderate osteoarthritis (OA) of the hip. Treatment of these patients can be challenging, as they are less likely to benefit from arthroscopy but may not yet be indicated for arthroplasty or due to age, are trying to delay arthroplasty. One orthobiologic solution includes cryogenically preserved amniotic suspension allograft (ASA). This is an allograft tissue composed of particularized amniotic membrane and cells from the amniotic fluid, which has been shown to improve pain in patients with knee OA. The purpose of our study was to evaluate the safety and efficacy of one ASA product injection in a patient population with moderate hip OA. We hypothesize that clinical results, as measured by patient-reported outcome tools (PROMs), will demonstrate at 12 months post-injection.
Methods
This was an IRB approved, multi-center, open-label pilot study of a cryogenically preserved ASA delivered as a single intra-articular injection for treatment of moderate hip OA. Ten patients with symptomatic hip osteoarthritis, defined as Tonnis grade 1 or 2 on radiographic examination, were prospectively enrolled. Other inclusion criteria included a minimum score of 2 on the Tegner activity scale, a seven-day average pain score of 4 or greater for the involved hip, and body mass index (BMI) less than 40. Exclusion criteria included a history of diabetes mellitus, rheumatoid arthritis or other autoimmune disorders, malignancy within 5 years, morbid obesity (BMI >40), pain medication or NSAID within 15 days prior to injection, use of pain medication for conditions unrelated to hip OA, anticoagulant use, use of immunosuppressive medication, corticosteroid or viscosupplementation injection within 6 months, infection within 3 months, hip dysplasia (CEA < 25 degrees and/or Tonnis angle > 10 degrees) and surgery of either hip within 6 months.
PROMs, including the iHOT12, mHHS, and SANE scores, were recorded at baseline, 6 months, and 12 months post-injection. A linear regression model was performed to detect differences in outcome scores from baseline.
Results
Ten patients were enrolled per the protocol. One patient did not feel the injection was properly administered, and had total hip arthroplasty 6 weeks after the injection. This left nine patients, all had completed 12-month data and were available for analysis. The cohort includes 5 males and 4 females, ages 47-67. iHOT scores demonstrated a significant improvement between baseline and 12 months (p = 0.02). SANE scores demonstrated a significant difference between baseline and 6 months (p < 0.01), as and between baseline and 12 months (p < 0.01). mHHS scores demonstrated a significant difference between baseline and 6 months (p = 0.02) and baseline and 12 months (p = 0.01). There were no major adverse events in the course of the study period.
Conclusion
The ASA hip injection is a safe, effective treatment for moderate hip osteoarthritis, with sustained clinical benefit at one year post-injection. Further randomized controlled trials are needed to compare the results of this ASA hip injections to other traditional treatment modalities and other ASA products.