Foreman CW, Callaghan JJ, Brown TS, Elkins JM, Otero JE Total Joint Arthroplasty in the Morbidly Obese: How Body Mass Index >/=40 Influences Patient Retention, Treatment Decisions, and Treatment Outcomes. J Arthroplasty. 2020 Jan;35(1):39-44. doi: 10.1016/j.arth.2019.08.019. Epub 2019 Aug 17.
Friedman RJ, Hess S, Berkowitz SD, Homering M Complication rates after hip or knee arthroplasty in morbidly obese patients. Clin Orthop Relat Res. 2013 Oct;471(10):3358-66. doi: 10.1007/s11999-013-3049-9. Epub 2013 May 14.
Milone MT, Shenoy K, Pham H, Jazrawi LM, Strauss EJ MRI analysis of peripheral soft tissue composition, not body mass index, correlates with outcomes following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2018 Dec;26(12):3711-3716. doi: 10.1007/s00167-018-4966-7. Epub 2018 May 3.
Muller M, Tohtz S, Winkler T, Dewey M, Springer I, Perka C MRI findings of gluteus minimus muscle damage in primary total hip arthroplasty and the influence on clinical outcome. Arch Orthop Trauma Surg. 2010 Jul;130(7):927-35. doi: 10.1007/s00402-010-1085-4. Epub 2010 Mar 11.
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.