The Use of Micronized Amniotic Membrane as an Adjunct in Long Bone Nonunion Surgery

Purpose: Nonunions are difficult to treat and carry a high financial burden. Human amniotic membrane tissue (AM) has been used in multiple orthopedic procedures to augment healing. Due to the complexity of nonunion repair, along with the difficulty with healing, micronized AM may aid in obtaining union during the patients’ nonunion repair surgery. Methods: : A single-center retrospective review at a level II trauma center was performed on consecutive patients 18 years of age or greater that were surgically treated for atrophic long bone (humerus, radius/ulna, femur, tibia) nonunion with adjunctive micronized AM (Clarix Flo®) from January 2020 through May 2022. Results: : A total of 26 patients (14 male, 12 female) aged 52.8 ± 18.8 years (range: 20-95 years) with 29.2 ± 8.0 BMI met the eligibility criteria and were included in the study analysis. All patients who had their nonunion repaired were followed for at least one year (range: 12- 24 months). Twenty-three patients 23/26, healed their nonunion, for overall union rate of 88.5%. The three patients that did not heal had co-morbidities including osteoporosis, Diabetes Mellitus, Ankylosis Spondylitis and Chronic Kidney Disease. There were no complications observed related to the micronized AM. Conclusion: Micronized AM added at the time of nonunion repair surgery resulted in 88.5% union rate in a diverse population of atrophic long bone nonunions.