Without knowing more about your father, his hip problems, and the study goals, it isn’t possible to say why your father should or shouldn’t participate. However, speaking about studies in general, there are advantages to participating if you meet the requirements.
When people participate in studies held at academic centers and hospitals, they are usually exposed to intense scrutiny. They are examined thoroughly before the study and during the study. In non-study situations, a patient may only be seen briefly by his or her surgeon, with some follow up. For patients in studies, they are seen more often by doctors and nurses who work within the study and are often available to answer questions and troubleshoot if there are any problems.
The major drawback that some people see with studies is that the study subjects, the patients, don’t usually know what treatment they are getting, the new one that is being tried, or the old one, or a sham treatment – depending on what the trial is. Ultimately, the decision has to be the patient’s.