Prediction of fracture nonunion leading to secondary surgery in patients with distal femur fractures

Direct and indirect costs of long bone fracture nonunions of the lower limb : the economic burden on the German healthcare system

Aims

Fracture nonunion represents a major complication in orthopaedic surgery, occurring in 5% to 10% of fracture patients. Fracture nonunions are associated with pain and loss of function, and lead to a substantial socioeconomic burden. The present retrospective cohort study analyzed direct and indirect costs and length of hospital stay, number of surgical procedures, and hospital (re-)admissions of nonunion patients.

Methods

Data from 18- to 65-year-old patients surgically treated for lower limb fractures and nonunions in a German level I trauma centre between 2012 and 2018 were analyzed. A total of 193 patients with nonunion were included, and 2,511 patients with fractures served as the control group. Direct costs were calculated using reimbursement according to the diagnosis-related group (DRG). Indirect costs were calculated including daily sickness allowance and productivity loss.

Results

The median healing time of nonunion patients was 45 weeks. Treatment expenses showed a 2.6-fold increase in direct costs, a 3.3-fold increase in indirect costs, and a 3.3-fold increase in total costs for nonunion patients compared to the control group. As every patient with a nonunion suffered from a fracture prior to nonunion treatment, costs were calculated by adding the median direct costs of €10,487 (IQR 9,173 to 15,262), median daily sickness allowance of €23,046 (IQR 14,892 to 36,264), median productivity loss of €85,714 (IQR 60,949 to 126,650), and median total socioeconomic burden of €123,334 (IQR 88,630 to 176,329).

Conclusion

Nonunions not only pose a significant burden on the injured individual and on healthcare systems, but also have a substantial socioeconomic impact. High direct and indirect costs illustrate that healing complications need to be detected and addressed as early as possible.

Exploring the relationship between frailty and nonunion fractures in upper extremity injuries: insights from the national inpatient sample

INTRODUCTION

Frailty, a physiological decline in functional capacity, may influence nonunion risk. This study aimed to investigate the association between frailty, as measured by the modified Frailty Index-5 (mFI-5), and the likelihood of nonunion fractures of the upper extremity.

METHODS

This retrospective cohort study utilized the national inpatient sample (NIS) from 2015 to 2019. Patients aged 18 and older with upper extremity fractures, identified by ICD-10-CM codes, were included. Patients were categorized into routine healing and nonunion groups. Frailty was assessed using the mFI-5, classifying patients as robust, prefrail, frail, or severely frail. Multivariate logistic regression, controlling for age, sex, and Injury Severity Score (ISS), was performed to determine the association between frailty and nonunion.

RESULTS

The study included 21,618 patients, with 3782 presenting with nonunion fractures. The median age was 69 years, and 60.5% were female. The most common fracture types in the routine healing group were forearm (40.1%), clavicle (18.4%), and humerus (16.9%), while in the nonunion group, humerus (30.4%) and scapula (32.1%) were most common. Multivariate logistic regression showed that frail and severely frail patients had a decreased risk of nonunion (OR 0.751 and 0.705, respectively, p < 0.001). Each unit increase in mFI-5 score was associated with a decreased risk of nonunion (OR 0.868, p < 0.001). Sub-analysis revealed a decreased risk of nonunion with increasing frailty for humerus, clavicle, scapula, and phalanx fractures, but no significant association for wrist, forearm, or metacarpal fractures.

CONCLUSION

Contrary to expectations, increasing frailty, as measured by the mFI-5, was associated with a decreased risk of nonunion fractures in the upper extremity. This paradoxical finding may be due to closer medical supervision and improved treatment compliance in frail patients. Further prospective studies are needed to explore the complex interplay between frailty, treatment adherence, and fracture healing.

Development and validation of a novel prediction model for osteoporosis : from serotonin to fat-soluble vitamins

Aims

We aimed to develop and validate a novel prediction model for osteoporosis based on serotonin, fat-soluble vitamins, and bone turnover markers to improve prediction accuracy of osteoporosis.

Methods

Postmenopausal women aged 55 to 65 years were recruited and divided into three groups based on DXA (normal, osteopenia, and osteoporosis). A total of 109 participants were included in this study and split into healthy (39/109, 35.8%), osteopenia (35/109, 32.1%), and osteoporosis groups (35/109, 32.1%). Serum concentrations of serotonin, fat-soluble vitamins, and bone turnover markers of participants were measured. Stepwise discriminant analysis was performed to identify efficient predictors for osteoporosis. The prediction model was developed based on Bayes and Fisher's discriminant functions, and validated via leave-one-out cross-validation. Normal and empirical volume under the receiver operating characteristic (ROC) surface (VUS) tests were used to evaluate predictive effects of variables in the prediction model.

Results

Significant variables including oestrogen (E2), total procollagen type 1 amino-terminal propeptide (TP1NP), parathyroid hormone (PTH), BMI, vitamin K, serotonin, osteocalcin (OSTEOC), vitamin A, and vitamin D3 were used for the development of the prediction model. The training accuracy for normal, osteopenia, and osteoporosis is 74.4% (29/39), 80.0% (28/35), and 85.7% (30/35), respectively, while the total training accuracy is 79.8% (87/109). The internal validation showed excellent performance with 72.5% testing accuracy (72/109). Among these variables, serotonin and vitamin K exert important roles in the prediction of osteoporosis.

Conclusion

We successfully developed and validated a novel prediction model for osteoporosis based on serum concentrations of serotonin, fat-soluble vitamins, and bone turnover markers. In addition, interactive communication between serotonin and fat-soluble vitamins was observed to be critical for bone health in this study.

Management of Distal Femoral Non-union: A Systematic Review

Introduction

Managing distal femur fracture nonunion is complex, with unpredictable results. The present investigation systematically updates current evidence, reviews existing modalities, innovations and related outcomes, and discusses future perspectives on the management of nonunion of the distal femur.

Methods

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the 2020 PRISMA statement. In April 2024, PubMed, Web of Science, Google Scholar, and Embase were accessed without time constraints. No additional filters were used in the database search. All the clinical studies investigating treatment options for nonunion of distal femur fractures were accessed.

Results

35 clinical studies (832 patients) were included. Of them, 34.2% (239 of 698 patients) reported an open fracture, and 24.5% (78 of 319 patients) reported infection at the fracture site. The mean length of the follow-up was 28.9 ± 13.2 months. The mean age of the patients was 53.8 ± 14.7 years.

Conclusion

84.5% (703 of 832) of patients reached complete union without major complications, and 3.8% (32 of 832) reached complete union with major complications at a mean of 21.7 ± 20.9 months. 8.7% (72 of 832) patients showed signs of persistent non-union.

Level of evidence

Level III, systematic review.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01205-4.

Mechanism research of elastic fixation promoting fracture healing based on proteomics and fracture microenvironment

Aims

This study aimed to demonstrate the promoting effect of elastic fixation on fracture, and further explore its mechanism at the gene and protein expression levels.

Methods

A closed tibial fracture model was established using 12 male Japanese white rabbits, and divided into elastic and stiff fixation groups based on different fixation methods. Two weeks after the operation, a radiograph and pathological examination of callus tissue were used to evaluate fracture healing. Then, the differentially expressed proteins (DEPs) were examined in the callus using proteomics. Finally, in vitro cell experiments were conducted to investigate hub proteins involved in this process.

Results

Mean callus volume was larger in the elastic fixation group (1,755 mm3 (standard error of the mean (SEM) 297)) than in the stiff fixation group (258 mm3 (SEM 65)). Pathological observation found that the expression levels of osterix (OSX), collagen, type I, alpha 1 (COL1α1), and alkaline phosphatase (ALP) in the callus of the elastic fixation group were higher than those of the stiff fixation group. The protein sequence of the callus revealed 199 DEPs, 124 of which were highly expressed in the elastic fixation group. In the in vitro study, it was observed that a stress of 200 g led to upregulation of thrombospondin 1 (THBS1) and osteoglycin (OGN) expression in bone marrow mesenchymal stem cells (BMSCs). Additionally, these genes were found to be upregulated during the osteogenic differentiation process of the BMSCs.

Conclusion

Elastic fixation can promote fracture healing and osteoblast differentiation in callus, and the ability of elastic fixation to promote osteogenic differentiation of BMSCs may be achieved by upregulating genes such as THBS1 and OGN.