On October 13, 2012, a Saturday morning, I came to the home of Mrs. Bu (a pseudonym is used here to protect the patient’s privacy), who lives in Shangnan New Village, Pudong New Area, to make a follow-up visit after her artificial joint surgery. It had been exactly six months since Bu had undergone total hip surgery for a fractured femoral neck. Although I called her daughter again and again and asked her to come to the hospital for a follow-up visit at her convenience, she always refused. The daughter said that the old woman had recovered well from the surgery and was walking at home as usual, basically without being able to tell that she had broken a bone or that she was using an artificial joint. The old man was stubborn and felt that there was no problem after the surgery, so he did not want to go to the hospital for a review, and said that it was a waste of money to review the film. With the purpose of being responsible for the patient, I decided to make a special home visit after communicating with Mrs. Bu’s daughter several times and obtaining her consent. At Mrs. Bu’s home, I saw that, as her daughter said, she had recovered very well from the surgery, and her gait was smooth and painless when she walked, and she had no problem going up and down stairs, so she was very satisfied. At the same time, I did a special physical examination and found that the surgical incision was healing well, with no local redness, swelling or heat, no pressure pain or percussion pain, good range of motion in all directions of the hip joint, and equal length of both lower limbs. The only thing left to do was to take post-operative x-rays, as this could only be done in the hospital and the old lady did not want to go there. Next, I spent about fifteen minutes doing my best to persuade Mrs. Bu to go to the hospital to have the post-operative films taken in one visit. To do this, I stated the following reasons: First, outpatient follow-up after artificial joint surgery is a routine part of post-operative care for joint disease. This is not quite the same as seeing a doctor in the usual sense. Usually, people go to the hospital only when they are uncomfortable, but after artificial joint surgery, patients need to go to the hospital for regular checkups whether they are uncomfortable or not; second, the purpose of follow-up visits after artificial joint surgery is to evaluate the recovery of patients and guide them to further rehabilitation exercises to improve the results of surgery; third, another important purpose of postoperative follow-up visits is to detect possible complications as early as possible through physical examination and radiographs. Third, another important purpose of postoperative follow-up is to detect some possible complications, such as deep vein embolism in the lower extremity, periprosthetic osteolysis and prosthetic loosening, through physical examination and radiographs, so that the doctor can deal with them in time to improve the survival rate of the artificial joint and prolong its service life. Therefore, doctors hope that patients who have undergone artificial joint surgery will gradually develop the concept of regular follow-up, that is, do not go to the hospital to see the doctor only when they feel that something is wrong, but when they feel fine, they can not go to the doctor! This is because some long-term complications become difficult to deal with if they wait until the patient has obvious conscious symptoms, which not only increases the cost of treatment, but also makes the surgery more difficult and less effective. Whether it is the patient or the doctor, these are things we do not want to see! However, the current situation is that patients generally do not develop good habits of postoperative follow-up, and surgeons often seriously neglect the importance of this task! Although I realized this early on, I could only carry out proactive follow-up on a small scale with my own patients who had undergone surgery. Even among my own patients, I encountered patients like Mrs. Bu who were stubborn and could not be “invited” repeatedly! After my explanation and persuasion, Mrs. Bu finally agreed to come to the hospital once in the near future to complete the routine postoperative radiographs. This follow-up visit finally achieved the intended purpose and effect! This reminds me of my own study at the University of Hong Kong School of Medicine, where I was extremely impressed by the long-standing standardized and meticulous post-operative follow-up work of the Department of Joint Replacement Surgery at Queen Mary Hospital. Instead of going into the details of the follow-up, I would like to illustrate the importance of follow-up through the “lining replacement surgery”. I have been involved in this surgery many times in Hong Kong. The patients were several years after total hip replacement, because of the asymmetric wear of the polyethylene lining after long-term use of the artificial hip joint. At this time, the patient had no symptoms or signs, only changes in lining thickness on radiographs, but no signs of osteolysis yet, and no loosening of the prosthesis, so there did not seem to be an urgent need for treatment. However, it is in this situation that the patient needs to undergo “liner replacement surgery”. This is a partial revision procedure, since, in addition to removing the granulation tissue containing the worn particles, only the worn lining is replaced with a new one, leaving the other parts (acetabular cup, femoral prosthesis stem and artificial femoral head) in place. The operation was simple, quick, minimal damage, and inexpensive, but the results were excellent, because it stopped further wear of the old lining, removed a large number of fine wear particles, effectively delayed the two major complications of periprosthetic osteolysis and prosthetic loosening, and avoided the extensive and difficult revision operations that could have resulted. This is a very necessary and timely remedial surgery as it postpones the scrapping of the whole machine. The diagnosis of visible wear of the polyethylene lining came from a plain radiograph taken during a long-term post-operative follow-up of the artificial joint! Without the surgeon’s attention to post-operative follow-up and the patient’s cooperation with post-operative follow-up, these small details that can cause major problems can easily be overlooked. If the patient is not treated until the clinical signs of osteolysis and loosening occur, the surgeon may be faced with a complex and difficult revision surgery with a much higher failure rate. Unfortunately, it seems to be becoming more and more common for me to have to do this kind of revision surgery. This shows how important post-operative follow-up is! I’ve always liked the phrase “be prepared for a rainy day”, which not only describes the importance of preoperative preparation, but also perfectly captures the essence of the post-operative follow-up process for artificial joints. Whenever I think of my clinical experience in the Department of Orthopaedics at the University of Hong Kong and the follow-up cases that are deeply imprinted in my mind, I ask myself not only to do a good job in every artificial joint surgery, but also to persevere in the post-operative follow-up of every patient!