Kwofie MK, Shastri UD, Gadsden JC, Sinha SK, Abrams JH, Xu D, Salviz EA The effects of ultrasound-guided adductor canal block versus femoral nerve block on quadriceps strength and fall risk: a blinded, randomized trial of volunteers. Reg Anesth Pain Med. 2013 Jul-Aug;38(4):321-5. doi: 10.1097/AAP.0b013e318295df80.
Macfarlane AJ, Prasad GA, Chan VW, Brull R Does regional anesthesia improve outcome after total knee arthroplasty? Clin Orthop Relat Res. 2009 Sep;467(9):2379-402. doi: 10.1007/s11999-008-0666-9. Epub 2009 Jan 7. Review.
Turnbull ZA, Sastow D, Giambrone GP, Tedore T Anesthesia for the patient undergoing total knee replacement: current status and future prospects. Local Reg Anesth. 2017 Mar 8;10:1-7. doi: 10.2147/LRA.S101373. eCollection 2017. Review.
Postoperative Pain in Total Knee Arthroplasty: a Comparison Between General and Spinal Anesthesia
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.