I have a PubMed alert for studies involving search with “machine learning”. This study was included in the search list recently: “One-year Follow-Up Results with Hydrogel Implant in Therapy of Hallux Rigidus: Case Series with 44 Patients“. That really stood out. But yes, they indeed used machine learning algorithm to investigate risk factors for treatment failure in a case series with 44 patients. Unfortunately I have no access for the full-text.