Prolotherapy is an injection technique. Its success relies heavily on the ability of the doctor to be an expert at creating the inflammatory healing response. This is covered in my article Osteoarthritic bone repair. Most doctors who are doing PRP injections are not Prolotherapists, they are surgeons. In one interesting case, a young lady had seen an orthopedic surgeon who apparently had gone to a weekend course and now was doing PRP injections. The orthopedic surgeon as far as I could tell had absolutely no training in Prolotherapy. All he was doing was injecting PRP into an area that he normally would inject steroids.