These days almost all surgeons have a specialist area so that generalisations on the subject are impossible.  However, from a legal point of view there are recurring issues that are important.

Perhaps the most obvious issue central to all surgical cases is the issue of consent.  Except for emegency situations, all surgeons need to have taken the patients agreement to have the surgery in advance.  There is a line of case law that describes what the surgeon must (and need not) explain to the patient so that the consent is valid.  When a patient has sufferd from a poor outcome, it is natural that they might wish that they had never undergone an operation.  Hindsight however must be disregarded and we must consider what the alternative course would have been if the surgery had not been performed, different surgery had been performed or a second opinion sought.

Other issues that need consideration are the degree of the surgeon's skil during the procedure itself, the preplanning ahead of the surgery and the post-operative care.