China is the most populated country in the world, and now has the second-largest economy in the world [7]. As nearly 166 million Chinese are aged more than 65 years [8]. The demand for healthcare, including hip arthroplasty is increasing [9, 10]. There are several predict complications model have be reported [11, 12, 13], but on one is modeling by Chinese. In this study, 59 of the 414 elderly total hip replacement patients who underwent surgical treatment were developed postoperative complication, the incidence is 14.3%, morbidity is much higher than 3.9% [14]. Probably because our definition of complications not only included dislocation, pulmonary embolism, and infection as reported previously, but included systemic inflammatory response syndrome, delirium which are common in elderly. Among 566 older patients (mean age, 76.7 years) undergoing a variety of elective operations (including orthopedic, general, and vascular), 23.9% patients developed postoperative delirium [15]. The incidence of postoperative delirium was reported as 7.0%-30.2% in hip arthroplasty [16, 17]. In this study the average age is 75.09 ± 7.8. As a result, the morbidity 14.3% is considered to be reasonable.
Age is a recognized risk factor for postoperative complications. The results of this study indicate that elderly patients with renal failure and diabetes are more likely to have postoperative complications after total hip replacement. It is Consistent with the research results of Robert K [18] et al. One possible reason is that elderly patients have more comorbidities will make them less able to withstand the stresses of anesthesia and surgery [19, 20]. Diabetes have been reported to be significant predictors for complications such as surgical site infections [21]. The available data suggest that diabetes may promote the development of osteoarthritis [22]. Our results for the outcome measure indicate that elderly patients with renal failure and diabetes increase the weight of the nomogram model score by 25 points and 24 points, respectively.
Interestingly, our data suggest that low preoperative albumin levels can predict the incidence of postoperative complications following surgery for total hip replacement. Since ALB is a biomarker of visceral protein and immune-competence status, it is commonly used for nutritional assessment [23]. Preoperative albumin bears strong potential as a practical metric to assess a patient’s overall health [24]. Recent studies even show that low ALB rather reflects a state of persistent inflammation [25]. Our results pointed out that the weight of 12.7 points in the nomogram model score will be increased for every 5 g/L decrease in ALB. We recommend surgeons and anesthetists should ideally attempt to optimize patient nutritional status before total hip replacement in elderly in order to avoid a greater likelihood of postoperative complications or mortality.
However our study has several limitations. First, our data were limited only 414 patients, it only represents an elective patient population. Second, complications were only collected while in hospital, some of these complications could have occurred after discharge. Third, the predict model quality checks only with internal validation, so external validation will have to be included in future studies in order to promote use. Fourth, this was a retrospective study that relied on 9th edition coding, which can lead to errors and/or incomplete coding.
Risk calculators should serve as a tool to help clinical decision-making, promote individualized medicine, and aid in the shared decision-making process [26]. Many of the studies report poor discrimination and calibration of the investigated risk calculators. In our study, founded that age, diabetes, renal failure, and Albumin value are independent risk factors for postoperative complications in elderly patients with total hip replacement, ROC curve shows the AUC is 0.8254, indicating that the nomogram model has a good discrimination. The Hosmer-Lemeshow fit goodness test x2 = 10.16, P = 0.4264 and calibration curve is a straight line with a slope close to 1, indicating that the nomogram model has good accuracy in predicting the risk of postoperative complications in elderly patients with total hip replacements surgery and has clinical application value.