The continuous acceleration of the aging process has made hip fracture among the top ten causes of disability worldwide[15], and hip fracture has become a global public health problem. Although the progress in surgical treatment is remarkable, a series of problems can affect postoperative recoveries, such as difficult predicted complications, surgical site infections, and refractures. In the study by Mingli et al.[16], 18.7% still had poor recovery after surgical treatment. In the study by Xia et al.[17], the excellent and good rate of recovery 1 year after surgery was only 77.11% (64/90). In this study, the good recovery rate after femoral neck fracture was 77.83%, which is consistent with the data of the above scholars, indicating that the postoperative outcome of hip fracture is relatively severe. The factors affecting the outcome of patients with femoral neck fracture should be paid attention to and identified, and the rate of good recovery should be improved after femoral neck fracture.
Nutritional status is both an inducement and a prognostic factor for femoral neck fractures. Malnutrition can increase the risk of falls, diminish bone mass, and increase the risk of refracture[18]. During the healing of femoral neck fractures, multiple pathophysiological changes are strongly associated with nutritional status. Preoperative nutritional reserve directly affects immune function and healing ability and has a direct impact on fracture recovery. This study exhibited that the MNA-SF score of the good recovery group after hip fracture was higher than that of the poor recovery group, which also indicated that preoperative nutritional status could affect the postoperative recovery of hip fracture. It is suggested that perioperative nutritional management of patients should be done well in the clinic, attention should be paid to the nutritional status before the operation, adequate nutritional assessment should be carried out, and nutritional support should be actively provided.
In addition to nutritional status, postoperative activity also affects the recovery after fractures. Although there are good reasons to apply immobilization measures in the early stage of fracture surgery, neglect may lead to secondary dysfunction and affect postoperative recovery [19–20]. Biomechanical and animal studies have shown that the stress of early adaptation to the fracture site has a positive effect on postoperative recovery after fractures. In the present study, the time of starting weight-bearing in the good recovery group after hip fracture surgery was shorter than that in the poor recovery group, indicating that weight-bearing after surgery could improve the postoperative recovery of hip fracture. Because the postoperative healing of fractures is affected by active factors such as blood supply, mechanical stress stimulation, and the degree of injury, mechanical stimulation is the main factor. On the one hand, it can stimulate osteoblast proliferation, differentiation, and secretion of extracellular matrix. On the other hand, by acting on the bone microenvironment, it can promote the release of local growth factors, which is conducive to angiogenesis at the fracture end. Therefore, early postoperative weight-bearing can create favorable conditions for the early recovery of fractures.
The development of the biopsychosocial medical model makes modern medical work no longer limited to diseases, but to recognize the relationship between human health and diseases from a holistic and systematic perspective, gradually paying attention to the psychology, behavior, and sociality of patients. Due to the behavioral alterations induced by hip fractures, these patients are worried about their future adaptability. Furthermore, when the body is injured, the spirit and mind are also severely hit beyond the stress threshold, which affects patient’s social role and is not conducive to postoperative recovery of fractures. The studies by Smith et al.[21]and Gilboa et al.[22] exhibit that social support is one of the most potential resources for hip fracture patients in the process of coping with fracture and treatment. Effective social support can enable patients to overcome negative coping emotions. Koivunen et al.[23] found that social support for independent living after fracture in elderly patients is a predictor of mortality. Sale et al.[24] concluded that physical and emotional support provided by nursing staff can improve the outcome of patients with insufficiency fractures. In this study, the SSRS score of the good recovery group after femoral neck fracture was higher than that of the poor recovery group, confirming the importance of social support. Social support is the psychological and material support or assistance that an individual receives from society, family, and other aspects under stress. As an important resource that can be used in nursing work, it has a positive relationship with human health and has both a stimulatory effect and a direct independent protective effect. Therefore, nursing workers should establish a sound social support system to help patients effectively use the social support network, and help them actively seek more effective and multi-faceted support and help, which can mobilize patients to consciously adjust their psychological pressure and actively participate in treatment and nursing with a positive attitude to speed up recovery.
The advent of the era of big data has made data mining and machine learning more and more extensively utilized in the medical field. The decision tree model algorithm can deal with the interaction between variables, analyze the specific form of a factor acting on each subgroup, and provide a reasonable analysis method for predictions. There are many factors affecting the postoperative recovery of hip fractures. In this study, the constructed decision tree model algorithm contained six features, including MNA-SF score, SSRS score, time of starting weight-bearing after the operation, operation time, Charlson comorbidity index, and walking aids. The five-layer model had the highest accuracy. However, FI-CGA, fasting blood glucose, hemoglobin, albumin, age, intraoperative blood loss, and blood transfusion volume were not included in the decision tree model. This is probably associated with the following factors: MNA-SF scale consists of somatometric measurement, diet evaluation, overall evaluation, and self-evaluation; compared with FI-CGA, fasting blood glucose and hemoglobin can fully reflect the nutritional status of patients; intraoperative blood loss is timely treated. Decision tree analysis revealed that the root node of the decision tree model was the MNA-SF score, which indicated that the MNA-SF score had the highest correlation with the postoperative recovery of femoral neck fractures, and was the most important influencing factor. Internal validation results of patients included in the study using the best parameters obtained demonstrated that the model had an accuracy of 88.18%, a sensitivity of 93.33%, a specificity of 86.71%, a positive predictive value of 66.67%, and a negative predictive value of 97.86%. The decision tree model intuitively presented the importance of the influencing factors such as MNA-SF score, SSRS score, and the time of starting weight-bearing after surgery on the postoperative recovery of femoral neck fractures and the interaction between variables, which is conducive to better understanding the relationship between various factors and the relationship with the postoperative recovery of femoral neck fractures, and provide a theoretical basis for the development of clinical nursing work.
In summary, preoperative nutritional status is the most important factor affecting the postoperative recovery of elderly femoral neck fractures, and the establishment of a decision tree model can better show various factors affecting postoperative recovery of femoral neck fractures in elderly patients. This study also has some limitations. The sample size is small. Only one type of fracture, femoral neck fractures, is discussed, and only the included cases are used for internal verification, which may lead to bias in the results. The amount of data will be further expanded in the future for external validation to optimize model parameters.