Impact of Renal Function on the Surgical Outcomes of Displaced Femoral Neck Fracture in Elderly Patients

The Nomogram Model and Factors for the Postoperative Mortality of Elderly Patients with Femoral Neck Fracture Undergoing Artificial Hip Arthroplasty: A Single-Institution 6-Year Experience

OBJECTIVE

Artificial hip arthroplasty (AHA) is widely accepted in elderly patients with femoral neck fractures, but it is associated with high risk of death and various postoperative complications due to old age and accompanying chronic diseases. Therefore, this study aimed to explore the risk factors for death in elderly patients with femoral neck fractures after AHA and to establish a nomogram risk prediction model, which is expected to reveal high-risk patients and improve the postoperative quality of life and survival rate of patients.

METHODS

Elderly patients who underwent AHA for femoral neck fractures in our hospital from September 2014 to May 2021were retrospectively analyzed. These patients were divided into a survival group and a death group according to their clinical outcomes. The following clinical data were recorded for the patients in the two groups: sex, age, underlying diseases, smoking and drinking history, preoperative nutritional risk score (NRS) and American Society of Anesthesiologists (ASA) score, as well as relevant indicators about the operation. These data were subject to univariate analysis and then logistic analysis to determine the risk factors of death. Subsequently, a nomogram risk prediction model was established and further validated with the receiver operating characteristic curve (ROC) and the Hosmer-Lemeshow test. Finally, the effects of predictive risk factors were analyzed using the Kaplan-Meier survival curve.

RESULTS

Follow-up was completed by 260 patients, including 206 patients in the survival group and 54 patients in the death group; the overall death rate was 20.77%, and the follow-up time, age, postoperative 1, 3 and 5-year death rates were 3.47 ± 1.93 years, 75.32 ± 9.12 years, 5.77%, 12.51%, and 25.61%, respectively. The top three causes of death in 54 patients were respiratory disease, cerebrocardiovascular disease, and digestive disease, respectively. The logistic analysis indicated that elderly patients with femoral neck fractures, the risk factors for death after AHA were age ≥ 80 years, preoperative NRS ≥ 4, HB ≤ 90 g/L, CR ≥ 110 umol/L, and ASA score ≥ 3, as well as postoperative albumin ≤ 35 g/L, the nomogram was established, and then its predictive performance was successfully validated using the ROC curve (AUC = 0.814, 95% confidence interval = 0.749-0.879) and the Hosmer-Lemeshow test (p = 0.840). Furthermore, Kaplan-Meier survival curve analysis revealed that the abovementioned six indicators were correlated with the post-AHA survival time of elderly patients with femoral neck fractures (pLog Rank  < 0.05).

CONCLUSION

Old age, preoperatively high NRS and ASA score, anemia, poor renal function, and postoperative hypoproteinemia are the major risk factors for death in elderly patients with femoral neck fractures after AHA; they are also associated with postoperative survival. Early identification and effective interventions for optimization of modifiable risk factors are recommended to improve the postoperative quality of life and survival rates.

The impact of chronic kidney disease and dialysis therapy on outcomes of elderly patients with hip fractures: A systematic review and meta-analysis

BACKGROUND AND AIMS

Hip fractures are a commonly occurring comorbidity in patients with chronic kidney disease. To evaluate the comparative rates of post-operative complications, revision surgery, and mortality after hip fracture surgery in chronic kidney disease patients undergoing hemodialysis.

METHODS

A systematic search of the academic literature was performed according to the PRISMA guidelines across five databases: Web of Science, EMBASE, CENTRAL, Scopus, and MEDLINE. A random-effect meta-analysis was conducted to evaluate the overall comparative risks of post-operative complications in chronic kidney disease patients.

RESULTS

Out of 993 studies, 11 eligible studies were included in the review, with a total of 72618 chronic kidney disease patients (mean age: 75.3  ±  3.0 years), and 50566 healthy controls (75.3  ±  2.6 years). Meta-analysis revealed a higher risk of post-operative complications (Odd's ratio: 1.76), revision surgeries (1.69), and mortality-related outcomes (2.47) after hip fracture surgery in chronic kidney disease patients undergoing hemodialysis as compared to chronic kidney disease patients not undergoing hemodialysis.

CONCLUSION

We report higher risks of post-operative complications, revision surgery, and mortality in chronic kidney disease patients undergoing hemodialysis as compared to chronic kidney disease patients not undergoing hemodialysis.

Reoperation rate and implant survivorship compared between cementless and cemented bipolar hemiarthroplasty in femoral neck fracture patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is commonly associated with aging and disorders of mineral and bone metabolism. Femoral neck fracture (FNF) is one of the most common fractures among older adults with coexisting CKD, and bipolar hemiarthroplasty (BHA) is a preferred treatment. However, the optimal method of stem fixation has not been conclusively determined. Accordingly, this study aimed to investigate the reoperation rate and implant survivorship compared between cementless and cemented BHA in FNF patients with CKD.

METHODS

A total of 183 FNF patients with moderate to severe CKD who underwent BHA during 2003 to 2019 were recruited and divided into either the cemented (CT group, n = 56) or cementless (CL group, 127) groups. Demographic data, preoperative laboratory investigations, preoperative radiographic outcomes, perioperative outcomes, and 90-day morbidity, mortality, and reoperation rates for any reason were recorded and compared between groups. Kaplan-Meier survival analysis was used to compare implant survivorship between the CT and CL groups. Cox proportional hazards regression model was used to identify independent risk factors for implant survivorship.

RESULTS

There were no significant differences in patient characteristics or preoperative data between groups, except for Dorr's classification of proximal femoral geometry. The CT group had a significantly lower proportion of Dorr type A (p = 0.020), and a higher proportion of Dorr type C (p<0.001). The CT group also had significantly more intraoperative blood loss (p<0.01). No significant differences in morbidity or mortality were observed. The median follow-up time in the CT group and CL group was 22.6 months (range: 0-151) and 22.6 months (range 0-154), respectively (p = 0.607). The reoperation rate was 5.4% and 4.7% among CT and CL patients, respectively (p = 1.000). There was no significant difference in the mean survival time between the CT (139.5 ± 6.3 months, 95%CI: 127.1-151.8) and CL (142.5 ± 4.7 months, 95%CI: 133.2-151.7) groups (p = 0.880). Univariate and multivariate analyses revealed no independent risk factors for implant survivorship.

CONCLUSION

The results of this study showed no significant differences in the reoperation rate or implant survivorship between cemented and cementless BHA for treating FNF in moderate to severe CKD patients. A well-designed larger and longer-term study is needed to confirm these results.

A quantitative biomechanical study of positive buttress techniques for femoral neck fractures: a finite element analysis

Background:

Refractory femoral neck fractures cannot be anatomically reduced by closed traction reduction which may affect fracture healing. We evaluated the biomechanical effects of positive, negative, and anatomic reduction of various degrees of displacement in Pauwels I femoral neck fractures by a finite element analysis.

Methods:

Five reduction models of Pauwels type I femoral neck fracture were established using the Mimics 17.0 (Materialize, Leuven, Belgia) and Hypermesh 12.0 (Altair Engineering, Troy, MI, USA). According to the degree of fracture displacement, there were three models of positive support, an anatomic reduction model, and a negative 2 mm reduction model. Finite element analysis was conducted using the ABAQUS 6.9 software (Simulia, Suresnes, France). The von Mises stress distribution and the stress peak of internal fixation in different models, the displacement between fracture blocks, and the principal strain of the femoral neck cancellous bone model were recorded under the axial stress of 2100 N.

Results:

The peak von Mises stress on screw of each model was located at the thread of the screw tip. The peak von Mises stress was the lowest at the tip of the anatomic reduction model screw (261.2 MPa). In the positive 4 mm model, the von Mises stress peak was the highest (916.1 MPa). The anatomic reduction model showed the minimum displacement (0.388 mm) between fracture blocks. The maximum displacement was noted in the positive 4 mm model (0.838 mm). The displacement in the positive 3 mm model (0.721 mm) was smaller than that in the negative 2 mm model (0.786 mm). Among the five models, the strain area of the femoral neck cancellous bone was mainly concentrated around the screw hole, and the area around the screw hole could be easily cut.

Conclusions:

Compared with negative buttress for femoral neck fracture, positive buttress can provide better biomechanical stability. In Pauwel type I fracture of femoral neck, the range of positive buttress should be controlled below 3 mm as far as possible.