I would like to know if there is any medical negligence concerning aftercare from a surgery.

Blood clots following knee surgery are well known complication which should be anticipated. You woud expect when a patient complains of symptoms consistent with a DVT following knee surgery that the condition will be ruled out because DVTs can turn into pulmonary embolisms or strokes, which can be life-threatening.  You have not explained the outcome of the failure to diagnose the condition. If it was merely a delay in diagnosis and no additional harm occurred, you probably do not have a financially viable malpratice. If the delay resulted in complications that lead to a permanent injury, you should contact an attorney to investigate a case. If you want to investigate a malpractice case, you should contact a local medical malpractice attorney (one in your state).  They take these cases on a contingency basis which means you only have to pay if you succeed.  Additionally, initial consultations are usually free. You can use the "Find a Lawyer" service through this website to research medical malpractice attorneys.  Then, visit each attorney's website and look for a firm that has a record of successful verdicts,  ideally with experience in cases that involve your medical issue. If you are unable to find a lawyer who meets these qualifications within your state, sometimes you may contact an out of state lawyer who can refer you to a qualified attorney in your state while providing support related to the issues of medicine. Below are some articles you may find helpful.  They are written for a New Jersey audience (where I practice) but the ideas discussed in these articles usually apply in most other jurisdictions as well. Click here for an article that discusses the three main questions I ask when deciding whether to investigate a potential medical malpractice case. This discusses the issue of financial viability. Click here for an article that explains what you can and should expect when pursuing a medical malpractice case. Click here, here  and here for more information about me. Click here for summaries of some of the cases that I have litigated. Since I am a lawyer, I need to advise you of the following when I communicate with you: Please note that by attempting to answer your question, I am not acting as your attorney. I will do nothing further to protect or preserve your interests in the absence of any additional discussion with you about this matter. John Ratkowitz, Esq. Starr, Gern, Davison & Rubin, P.C. 105 Eisenhower Parkway Roseland, NJ 07068 Office: (973) 830-8441 Cell: (732) 616-6278 Fax: (973) 226-0031 Email: jratkowitz@starrgern.com  Skype: john_ratkowitz Click here for my website.