Early prediction of femoral head avascular necrosis following neck fracture

Residual deformity after femoral neck fracture affects the location of osteonecrosis of the femoral head

Aims

The localization of necrotic areas has been reported to impact the prognosis and treatment strategy for osteonecrosis of the femoral head (ONFH). Anteroposterior localization of the necrotic area after a femoral neck fracture (FNF) has not been properly investigated. We hypothesize that the change of the weight loading direction on the femoral head due to residual posterior tilt caused by malunited FNF may affect the location of ONFH. We investigate the relationship between the posterior tilt angle (PTA) and anteroposterior localization of osteonecrosis using lateral hip radiographs.

Methods

Patients aged younger than 55 years diagnosed with ONFH after FNF were retrospectively reviewed. Overall, 65 hips (38 males and 27 females; mean age 32.6 years (SD 12.2)) met the inclusion criteria. Patients with stage 1 or 4 ONFH, as per the Association Research Circulation Osseous classification, were excluded. The ratios of anterior and posterior viable areas and necrotic areas of the femoral head to the articular surface were calculated by setting the femoral head centre as the reference point. The PTA was measured using Palm's method. The association between the PTA and viable or necrotic areas of the femoral head was assessed using Spearman's rank correlation analysis (median PTA 6.0° (interquartile range 3 to 11.5)).

Results

We identified a negative correlation between PTA and anterior viable areas (rho -0.477; p = 0.001), and no correlation between PTA and necrotic (rho 0.229; p = 0.067) or posterior viable areas (rho 0.204; p = 0.132).

Conclusion

Our results suggest that residual posterior tilt after FNF could affect the anteroposterior localization of necrosis.

What are the differences in the recovery of physical function and clinical score between patients with steroid-related osteonecrosis of the femoral head and hip osteoarthritis undergoing total hip arthroplasty? A propensity score-matched study

PURPOSE

Steroid-related osteonecrosis of the femoral head (ONFH), arising from steroid administration for underlying diseases, represents a unique pathology for total hip arthroplasty (THA) and typically affects a younger demographic compared to osteoarthritis (OA). Given the significant age-related differences, this study aims to employ propensity score matching to align patient backgrounds between these two diseases and compare physical function. Additionally, our objective is to scrutinize the patterns of clinical score recovery over the course of one year following THA.

METHODS

Using propensity score matching, 29 patients each with steroid-related ONFH and OA were selected. Muscle strength (hip abductor and knee extensor) were assessed before and after THA. Additionally, recovery of the Harris Hip Score (HHS) and Oxford Hip Score (OHS) up to one year postoperatively was analyzed.

RESULTS

The steroid-related ONFH group exhibited gender bias and significantly younger age compared to the OA group. Propensity score matching achieved balanced patient backgrounds. Physical function showed trends of lower hip abduction and knee extensor strength on the operative side in the steroid-related ONFH group. Notably, nonoperative knee extensor strength decreased significantly after matching. HHS and OHS were poor in steroid-related ONFH up to three months postoperatively but recovered after six months.

CONCLUSIONS

Patients with steroid-related ONFH experience positive outcomes in clinical score following THA. Propensity score matching effectively identified muscle weakness on both operative and nonoperative sides, highlighting its utility in comparative analyses.

Osteosynthesis, hemiarthroplasty, total hip arthroplasty in hip fractures: All I need to know

Recent data from the UK's National Hip Fracture Database (NHFD) demonstrate an upward trajectory in the incidence of hip fractures, a trend which is expected to persist. In 2023 alone, the NHFD reported 72,160 cases, underscoring the prevalence of these injuries. These fractures are associated with significant morbidity, mortality, and economic costs. National guidelines for the surgical management of these fractures are established, although the implementation of total hip arthroplasty (THA) as a primary treatment modality varies. This review offers a narrative synthesis of contemporary literature on hip fractures, focusing on epidemiology, classification systems, and treatment options, with a particular emphasis on the outcomes of THA.

Bioinformatic analysis of related immune cell infiltration and key genes in the progression of osteonecrosis of the femoral head

Objective

Osteonecrosis of the femoral head (ONFH) is a common orthopedic condition that will prompt joint dysfunction, significantly impacting patients' quality of life. However, the specific pathogenic mechanisms underlying this disease remain elusive. The objective of this study is to examine the differentially expressed messenger RNAs (DE mRNAs) and key genes linked to ONFH, concurrently investigating the immune cell infiltration features in ONFH patients through the application of the CIBERSORT algorithm.

Methods

Microarray was applied to scrutinize mRNA expression profiles in both ONFH patients and healthy controls, with data integration sourced from the GEO database. DE mRNAs were screened using the Limma method. The biological functions of DE mRNAs were explored through the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, Gene Ontology (GO) functional analysis, and Gene Set Enrichment Analysis (GSEA). Additionally, support vector machine-recursive feature elimination (SVM-RFE) and the least absolute shrinkage and selection operator (LASSO) were employed to discern diagnostic biomarkers associated with the disease. Receiver operating characteristic (ROC) analysis was utilized to assess the statistical performance of the feature genes. The validation of key genes was performed using qRT-PCR in bone tissues obtained from ONFH patients and healthy controls. Osteogenic differentiation of BMSC was then performed and detected by alkaline phosphatase staining (ALP) and qRT-PCR to verify the correlation between key genes and osteogenic differentiation. Finally, immune cell infiltration analysis was executed to evaluate immune cell dysregulation in ONFH, concurrently exploring the correlation between the infiltration of immune cells and key genes.

Results

After consolidating the datasets, the Limma method revealed 107 DEGs, comprising 76 downregulated and 31 upregulated genes. Enrichment analysis revealed close associations of these DE mRNAs with functions such as cell migration, osteoblast differentiation, cartilage development and extracellular region. Machine learning algorithms further identified APOD, FBXO43 and LRP12 as key genes. ROC curves demonstrated the high diagnostic efficacy of these genes. The results of qRT-PCR showed that the expression levels of key genes were consistent with those of microarray analysis. In addition, the results of in vitro experiments showed that APOD was closely related to osteogenic differentiation of BMSC. Immune infiltration analysis suggested a close correlation between ONFH and imbalances in levels of Neutrophils, Monocytes, Macrophages M2, Dendritic cells activated and Dendritic cells resting.

Conclusion

APOD is closely related to osteogenic differentiation of BMSCs and can be used as a diagnostic marker of ONFH. Immune cell infiltration significantly differs between controls and ONFH patients.

Management of Garden-I and II Femoral Neck Fractures: Perspectives on Primary Arthroplasty

This review compares internal fixation versus arthroplasty in the treatment of nondisplaced femoral neck fractures (FNFs) calling attention to evolving areas of consensus that influence clinical decision-making. The Garden classification system, typically dichotomized into nondisplaced (types I and II) and displaced (types III and IV) fractures, has been used as a guide for surgical decision-making. Conventionally, treatment of nondisplaced FNF in the elderly has been with internal fixation, and treatment of a displaced FNF has been hemi-, or more recently total hip, arthroplasty. Studies over the last decade have raised concern over the appropriate treatment of nondisplaced FNFs due to high rates of reoperation of nondisplaced FNFs treated with internal fixation. Avascular necrosis (AVN), failure of internal fixation, secondary malunion, and pin/nail penetration through the femoral head have all been observed. Several studies have attributed fixation failure to a degree of femoral neck tilt ≥20°, either posteriorly or anteriorly as seen on the lateral X-ray. Because of these observations of fixation failures, the suggestion has been made that arthroplasty be used when the degree of posterior tilt exceeds a threshold of ≥20° tilt with the expectation of diminishing failure of fixation, decreasing the risk of reoperation and preserving function without increasing mortality rate. Frustrating additional analyses are uncertainties over the mechanisms of failure of internal fixation with ≥20° tilt and the persistently substantial 1-year mortality rate after FNF, which has not been influenced by fixation or replacement type. Due to the lack of consensus regarding the determination of the appropriate surgical intervention for nondisplaced FNFs, an improved algorithm for surgical decision-making for these fractures may prove useful.

Methods to predict osteonecrosis of femoral head after femoral neck fracture: a systematic review of the literature

BACKGROUND

Femoral neck fracture (FNF) is a very common traumatic disorder and a major cause of blood supply disruption to the femoral head, which may lead to a severe long-term complication, osteonecrosis of femoral head (ONFH). Early prediction and evaluation of ONFH after FNF could facilitate early treatment and may prevent or reverse the development of ONFH. In this review paper, we will review all the prediction methods reported in the previous literature.

METHODS

Studies on the prediction of ONFH after FNF were included in PubMed and MEDLINE databases with articles published before October 2022. Further screening criteria were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. This study highlights all the advantages and disadvantages of the prediction methods.

RESULTS

There were a total of 36 studies included, involving 11 methods to predict ONFH after FNF. Among radiographic imaging, superselective angiography could directly visualize the blood supply of the femoral head, but it is an invasive examination. As noninvasive detection methods, dynamic enhanced magnetic resonance imaging (MRI) and SPECT/CT are easy to operate, have a high sensitivity, and increase specificity. Though still at the early stage of development in clinical studies, micro-CT is a method of highly accurate quantification that can visualize femoral head intraosseous arteries. The prediction model relates to artificial intelligence and is easy to operate, but there is no consensus on the risk factors of ONFH. For the intraoperative methods, most of them are single studies and lack clinical evidence.

CONCLUSION

After reviewing all the prediction methods, we recommend using dynamic enhanced MRI or single photon emission computed tomography/computed tomography in combination with the intraoperative observation of bleeding from the holes of proximal cannulated screws to predict ONFH after FNF. Moreover, micro-CT is a promising imaging technique in clinical practice.

Concomitant valgus hip osteotomy in operative fixation of displaced proximal femoral neck fractures

Total hip arthroplasty (THA) is considered the preferred treatment for displaced proximal femoral neck fractures. However, in many countries this option is economically unviable. To improve outcomes in financially disadvantaged populations, we studied the technique of concomitant valgus hip osteotomy and operative fixation (VOOF). This prospective serial study compares two treatment groups: VOOF versus operative fixation alone with cannulated compression screws (CCSs). In the first series, 98 hip fixation procedures were performed using CCS. After fluoroscopic reduction of the fracture, three CCSs were placed. In the second series, 105 VOOF procedures were performed using a closing wedge intertrochanteric osteotomy with a compression lag screw and lateral femoral plate. The alignment goal was to create a modified Pauwel's fracture angle of 30°. After fluoroscopic reduction of fracture, lag screw was placed to achieve the calculated correction angle, followed by inter-trochanteric osteotomy and placement of barrel plate. Patients were followed for a minimum of two years. Mean follow-up was 4.6 years (4.1 to 5.0) in the CCS group and 5.5 years (5.25 to 5.75) in the VOOF group. The mean Harris Hip Score at two-year follow-up was 83.85 in the CCS group versus 88.00 in the VOOF group (p < 0.001). At the latest follow-up, all-cause failure rate was 29.1% in the CCS group and 11.7% in the VOOF group (p = 0.003). The total cost of the VOOF technique was 7.2% of a THA, and total cost of the CCS technique was 6.3% of a THA. The VOOF technique decreased all-cause failure rate compared to CCS. The total cost of VOOF was 13.5% greater than CCS, but 92.8% less than a THA. Increased cost of VOOF was considered acceptable to all patients in this series. VOOF technique provides a reasonable alternative to THA in patients who cannot afford a THA procedure.

Combined Deflection Angle Classification: A Novel Typing System of Adult Femoral Neck Fracture

OBJECTIVE

Femoral neck fracture (FNF) is a common clinical trauma with high mortality and disability rates. Furthermore, its incidence increases exponentially with increasing age. Existing classifications have some disadvantages. Thus, this study aimed to establish a novel typing system for FNF.

METHODS

We retrospectively analyzed all adult patients with FNF admitted to our hospital between December 2015 and November 2017 for cannulated screw internal fixation. The study population was divided into the femoral varus offset group (VAR) and the valgus offset group (VAL). The data collected included sex, age, affected side, injury mode, body mass index, complications, pelvic incidence (PI), hip deflection angle (HDA), combined deflection angle (CDA), and neck shaft angle. Statistical analysis was conducted to determine the correlation between complications and deviation angles. A novel typing system was developed and compared with the Garden classification to detect its superiority.

RESULTS

A total of 108 patients were recruited, with 59 patients in the VAR and 49 patients in the VAL groups. The incidence of complications in the VAR group was significantly higher than that in the VAL group (P < 0.05). Moreover, there were more male participants in the VAR group. Compared with the VAL group, the VAR group had significantly higher PI, HDA, and CDA (P < 0.05). The CDA classification (CDAC) was defined, with CDA as the main criterion and HDA as the supplementary criterion. Furthermore, there was a hierarchical correlation between the actual incidence of complications and the typing level, which was increased in CDAC but not in the Garden classification. This showed that CDAC was more accurate.

CONCLUSION

A novel typing system, CDAC, for FNF was established, which was more accurate than the Garden classification. We suggest combining CDAC and Garden classifications for the preoperative diagnosis, treatment selection, and prognostic evaluation for patients with FNF.

Comparative Study Between Closed Reduction Internal Fixation Alone Versus Closed Reduction Internal Fixation and Addition of Muscle Pedicle Bone Graft for Prevention of Osteonecrosis in Cases of Displaced Femoral Neck Fractures

BACKGROUND

In patients of less than 60 years of age, osteosynthesis is the treatment of choice for displaced femoral neck fractures (Garden 3 and 4). Most of these fractures unite well but chances of osteonecrosis are quite high even after early operations and till date there is no well-defined method of prediction and prevention of osteonecrosis. Vascularized bone graft may prevent the development of osteonecrosis.

MATERIALS AND METHODS

This is a retrospective case control study done in an urban Medical College in eastern India and tried to evaluate efficacy of addition of quadratus femoris muscle pedicle bone graft in cases of osteosynthesis comparing the results of cases treated with closed reduction and internal fixation alone for femoral neck fractures We have taken into consideration 45 consecutive cases from each group with identical demographic background and of very similar age pattern of 20 years to 60 years.For further reference, we will describe Group I for closed reduction and CHS/DHS only, and Group II for closed reduction CHS and quadratus femoris muscle pedicle graft.

RESULTS

Satisfactory bony union occurred in 42 out of 45 follow-up patients in Group 1 (93.3%) and 43 out of 45 patients in Group 2. (95.5%) In 2- to 10-year follow-up period, eight patients (18.6%) developed osteonecrosis in Group I, and in Group 2, in the same period, there were no cases of osteonecrosis.

CONCLUSION

Addition of quadratus femoris muscle pedicle bone graft is a very effective procedure for prevention of osteonecrosis when we attempt osteosynthesis by closed reduction and internal fixation for displaced femoral neck fractures.

The role of internal fixation in the treatment of femoral head necrosis with ipsilateral hip fracture

Whether internal fixation or hip arthroplasty is the most appropriate initial treatment for patients with ipsilateral hip fracture and osteonecrosis of the femoral head remains unknown. In this study, the prognoses of patients who underwent internal fixation or hip arthroplasty were analyzed and compared to explore the role of internal fixation in treating such patients. We retrospectively reviewed 69 patients diagnosed with osteonecrosis of the femoral head and ipsilateral hip fracture from 1999 to 2018. They were divided into the hip arthroplasty or internal fixation group. The visual analog scale and Harris score were used. The incidence of complications and the conversion to arthroplasty were also investigated to further explore the role of internal fixation. Male patients (male/female: 25/31 vs 20/38, P = .015), younger patients (average age: 46.80 ± 13.14 vs 61.07 ± 15.61, P < .001), and patients with femoral neck fractures (fracture type, femoral neck/trochanter: 21/31 vs 12/38, P = .003) were more likely to receive 1-stage hip arthroplasty. Of 38 patients undergoing internal fixation, fracture nonunion was identified in 9, and progression of osteonecrosis was identified in 16. Meanwhile, conversion to secondary hip arthroplasty occurred in 13 patients. Four independent risk factors for conversion to secondary hip arthroplasty were identified: age of ≤60 years (odds ratio [OR] = 9.786, 95% confidence interval [CI] = 2.735-35.015), male sex (OR = 6.790, 95% CI = 1.718-26.831), collapse of the femoral head before injury (OR = 7.170, 95% CI = 2.004-25.651), and femoral neck fracture (OR = 8.072, 95% CI = 2.153-30.261). A new scoring system was constructed for predicting conversion to hip arthroplasty in patients undergoing internal fixation treatment. A cutoff of ≤2 points indicated low risk for conversion, 3 to 4 points indicated moderate risk, and ≥5 points indicated high risk. Patients who underwent internal fixation had worse prognoses than those who underwent 1-stage hip arthroplasty. However, in this study, hip arthroplasty conversion did not occur in most patients who received internal fixation. Using the new scoring system to identify patients who may require conversion to replacement may help make appropriate patient management and clinical decisions.

Musculoskeletal Trauma and Infection

MR is often the most definitive imaging for assessment of musculoskeletal trauma and infection. Although it is not possible to address all the intricacies of these complex topics in a single article, this review will attempt to provide a useful toolbox of skills by discussing several common clinical scenarios faced by emergency radiologists in interpretation of adult trauma and infection. These scenarios include MR assessment of hip and pelvic fracture, traumatic soft tissue injuries, septic arthritis, soft tissue infection, and osteomyelitis.

Multiple cannulated screw fixation of femoral neck fractures with comminution in young- and middle-aged patients

Objective

To investigate the distribution and influence of comminution in femoral neck fracture (FNF) patients after cannulated screw fixation (CSF).

Methods

From January 2019 to June 2020, a total of 473 patients aged 23–65 years with FNF treated by CSF were included in the present study. Based on location of the cortical comminution, FNF patients were assigned to two groups: the comminution group (anterior comminution, posterior comminution, superior comminution, inferior comminution, multiple comminutions) or the without comminution group. The incidence of postoperative complications, quality of life and functional outcomes was recorded at 1-year follow-up.

Results

Comminution was more likely to appear in displaced FNF patients (86.8%) compared with non-displaced FNF patients (8.9%), and the rate of comminution was closely associated with Pauwels classification (3.2% vs 53.5% vs 83.9%, P < 0.05). The incidence of osteonecrosis of the femoral head (ONFH, 11.3% vs 2.9%, P < 0.05), nonunion (7.5% vs 1.7%, P < 0.05), femoral neck shortening (21.6% vs 13.4%, P < 0.05) and internal fixation failure (11.8% vs 2.9%, P < 0.05) was significantly higher in FNF patients with comminutions, especially with multiple comminutions, than those without. Furthermore, there was a significant difference in the Harris hip score (HHS, 85.6 ± 15.6 vs 91.3 ± 10.8, P < 0.05) and EuroQol five dimensions questionnaire (EQ-5D, 0.85 ± 0.17 vs 0.91 ± 0.18, P < 0.05) between FNF patients with comminution and those without. There was no significant difference in Visual analogue scale scores (VAS, 1.46 ± 2.49 vs 1.13 ± 1.80, P > 0.05) between two groups at 1 year post-surgery.

Conclusion

Comminution is a risk factor for postoperative complications in young- and middle-aged patients with displaced and Pauwels type III FNF who undergo CSF. This can influence the recovery of hip function, thereby impacting quality of life. Further evaluation with a more comprehensive study design, larger sample and long-term follow-up is needed.

The Significance of Evaluating the Femoral Head Blood Supply after Femoral Neck Fracture: A New Classification for Femoral Neck Fractures

Objective

To compare a new classification with the Garden classification by exploring their relationships with vascular injury.

Methods

This retrospective study enrolled 73 patients with subcapital femoral neck fracture from July 2015 to November 2018, including 32 males and 41 females with an average age of 47.2 years. All patients were classified by the Garden classification using anteroposterior X‐ray imaging and by a new classification system based on three‐dimensional CT imaging. The blood supply of the affected femoral head in these patients was evaluated based on DSA images. Correlations between the two classifications and the degree of vascular injury were assessed.

Results

The results of the DSA examination indicated that eight patients had no retinacular vessel injury, 20 patients had one retinacular vessel injury, 35 patients had two retinacular vessel injuries, and 10 patients had three retinacular vessel injuries. The degree of vascular injury was used to match the two fracture classifications. Forty‐nine Garden classifications (Type I‐IV: 8, 12, 23, 6, respectively, 67.12%) and 66 new classifications (Type I‐IV: 8, 20, 32, 6, respectively, 90.41%) corresponded to the degree of vascular injury (p < 0.05). The Garden classification showed moderate reliability, and the new classification showed near perfect agreement (Interobserver agreement of k = 0.564 [0.01] in Garden classification vs. Garden classification k = 0.902 [0.01] for the five observers).

Conclusions

The new classification system can accurately describe the degree of fracture displacement and judge the extent of vascular injury.

Does the association of therapeutic exercise and supplementation with sucrosomial magnesium improve posture and balance and prevent the risk of new falls?

Background

Fracture of the proximal femur is the most feared complication of osteoporosis. Given the numerous physiological functions that magnesium performs in our body, in the literature there is a correlation between osteoporosis and low serum levels of magnesium.

Aim

Evaluate the incidence of hypomagnesemia in patients with lateral fragility fracture of the proximal femur, the possible correlation between serum magnesium levels and fractures, and the effectiveness of supplementing Sucrosomial^® magnesium associated with therapeutic exercise on the outcome of these patients.

Methods

We divided the study into two parts. In the first part, we assessed the preoperative incidence of hypomagnesemia in patients using a blood test. In the second part, patients with hypomagnesemia were divided, in the post-operative period, into two groups, who received, respectively, only therapeutic exercise or oral supplementation with sucrosomial magnesium associated with therapeutic exercise.

Results

Half of the patients with fragility femoral fracture had hypomagnesemia, with a higher incidence of the subclinical form. From the comparison between the two groups, the T1 treatment group showed a significant improvement in blood levels of magnesium (2.11 ± 0.15 vs. 1.94 ± 0.11; p < 0.05), on the NRS scale (5.7 ± 0.81 vs. 6.6 ± 1.18; p < 0.05), the Tinetti scale (17.3 ± 1.15 vs. 15.2 ± 2.98; p < 0.05) and the SarQoL questionnaire (47.3 ± 5.21 vs. 44.9 ± 5.54; p < 0.05).

Conclusions

More attention would be needed in the diagnosis and correction of subclinical hypomagnesemia and not just the simple and clinically evident one, including hypomagnesemia among the modifiable risk factors for osteoporosis.

Global Trends and Current Status in Osteonecrosis of the Femoral Head: A Bibliometric Analysis of Publications in the Last 30 Years

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) is a progressive and disabling disease with severe socioeconomic burdens. In the last 30 years, a growing number of publications have reported significant advances in understanding ONFH. However, only a few studies have clarified its global trends and current status. Thus, the purpose of our study was to summarize the global trends and current status in ONFH through bibliometrics.

MATERIALS AND METHODS

Publications related to ONFH from 1991 to 2020 were searched from the Web of Science (WOS) core collection database. The data were analyzed with bibliometric methods. Microsoft Excel was used for statistical analysis and to draw bar charts. SPSS was applied to perform linear regression analysis. VOSviewer was used to conduct bibliographic coupling analysis, co-authorship analysis, co-citation analysis and co-occurrence analysis.

RESULTS

A total of 5,523 publications were covered. The United States consistently ranked first in total publications, sum of times cited, average citations per item and H-index. Kyushu University was the main contributor to ONFH. Clinical Orthopaedics and Related Research was the major publishing channels for ONFH-related articles. Takuaki Yamamoto published the most ONFH-related articles. Studies regarding ONFH could be divided into five clusters: 1) mechanism study, 2) treatment study, 3) complication study, 4) radiological study and 5) etiological study. Mechanism study might become a hot spot in the future.

CONCLUSIONS

The total number of publications in ONFH has generally increased over the last three decades. The United States was the leading country in ONFH research. Transplantation, engineering, cell and molecular biology, pharmacology and endocrinology have gradually increased and become hot topics in ONFH research. Mechanism study in ONFH including mesenchymal stem cells, apoptosis, oxidative stress, adipogenesis, osteogenic differentiation and endothelial progenitor cells, have attracted more attention and will become a hot spot in the future.

Evolutionary course of the femoral head osteonecrosis: Histopathological - radiologic characteristics and clinical staging systems

Osteonecrosis of the femoral head (ONFH) is a recalcitrant ischemic disorder, which could be classified into two major categories: traumatic and nontraumatic. Regardless of different risk factors, it has been testified that ONFH results from primitive vascular problems, leading to temporary or permanent loss of blood supply to bone tissue. Histopathological and microarchitectural alterations ensues, which is a gradual evolutionary process involving bone marrow and osteocyte necrosis, progressive destruction of subchondral bone, unsuccessful reparative process, and eventual articular collapse and degenerative arthritis. Based on the imaging features of ONFH, different classification systems have been developed to evaluate the severity and prognosis of the disease, which is pivotal for implementation of treatment strategy, especially the joint-preserving surgery. However, patients classified with the same severity stage, especially in the peri-collapse stage, sometimes responded differently after similar joint-preserving surgery. The unusual phenomenon may be attributed to the limitation of the current imaging classification systems, which might underestimate the disease severity, especially when referring to the early stages. In this review, we briefly summarize the etiology and pathogenesis of ONFH. The imaging features and staging classification systems of ONFH are also described. More importantly, we focus on histopathological and microstructural alterations of the femoral head, and provide an overview of their essential contribution to ONFH progression. Given the observation of discordance between imaging characteristics and histopathological alterations, a substantial amount of research on the relationship between imaging and histopathological features is required to further modify and revise the current wide-accepted classification systems.

Quantitative contrast enhanced dual energy CT to predict avascular necrosis: a feasibility study of proximal humerus fractures

BACKGROUND

Avascular necrosis is a delayed complication of proximal humerus fractures that increases the likelihood of poor clinical outcomes. CT scans are routinely performed to guide proximal humerus fracture management. We hypothesized iodine concentration on post-contrast dual energy CT scans identifies subjects who develop avascular necrosis and ischemia due to compromised blood flow.

MATERIALS AND METHODS

55 patients with proximal humerus fractures enrolled between 2014 and 2017 underwent clinical, radiographic and contrast enhanced dual energy CT assessment. Iodine densities of the humeral head and the glenoid (control) were measured on CT. Subjects managed with open reduction internal fixation or conservatively (non-surgical) were followed for up to two years for radiographic evidence of avascular necrosis. Arthroplasty subjects underwent histopathologic evaluation for ischemia of the resected humeral head.

RESULTS

17 of 55 subjects (30.9%) were treated conservatively, 21 (38.2%) underwent open reduction internal fixation and 17 of 55 (30.9%) underwent arthroplasty. Of the 38 subjects treated conservatively or with ORIF, 20 (52.6%) completed 12 months of follow up and 14 (36.8%) 24 months of follow up. At 12 months follow up, two of 20 subjects (10%) and at 24 months 3 of 14 subjects (21.4%) developed avascular necrosis. At 12 months, the mean humerus/glenoid iodine ratio was 1.05 (standard deviation 0.24) in subjects with AVN compared to 0.91 (0.24) in those who did not. At 24 months, subjects with avascular necrosis had a mean humerus/glenoid iodine concentration ratio of 1.06 (0.17) compared to 0.924 (0.21) in those who did not. Of 17 arthroplasty subjects, 2 had severe ischemia and an iodine ratio of 1.08 (0.30); 5 had focal ischemia and a ratio of 1.00 (0.36); and 8 no ischemia and a ratio of 0.83 (0.08).

CONCLUSIONS

Quantifying iodine using dual energy CT in subjects with proximal humerus fractures is technically feasible. Preliminary data suggest higher humeral head iodine concentration may increase risk of avascular necrosis; however, future studies must enroll and follow enough subjects managed with open reduction internal fixation or conservatively for two or more years to provide statistically significant results. Trial Registrations NCT02170545 registered June 23, 2014, ClinicalTrials.gov.

Non-operative predictors for subsequent interventions after intracapsular femoral neck fractures in elderly: A comprehensive analysis of the Hungarian nationwide health insurance database

OBJECTIVES

To investigate the correlation between non-operative prognostic factors and non-prosthetic fracture-related treatments following internal fixation of intracapsular femoral neck fractures in elderly patients.

DESIGN AND SETTING

Retrospective observational cohort study. Comprehensive analysis of the Hungarian nationwide health insurance database.

PARTICIPANTS

Data of in-patient records with S7200 ICD-10 codes were collected from the Hungarian National Health Insurance Fund Administration (HNHIFA) and from the health care provider institutes. The patients with femoral neck fractures in the year of 2000, following reduction and internal fixation aged 60 years or older were evaluated. The secondary, non-prosthetic fracture related treatments during the 8 year follow-up period were registered.

MAIN OUTCOME MEASURES

Of the prognostic factors, age, gender, type of fracture, season and day of the primary surgery, length of waiting time to the operation and the accompanied diseases were evaluated as risk factors for all type of fracture-related further interventions, with the exception of arthroplasties.

RESULTS

A total of 2895 patients with intracapsular femoral neck fractures met the study criteria. The mean age was 77.96 years (SD: 8.54). The cohort of the patients was observed for a total of 10,077.8 person-years. The non-prosthetic fracture related treatment was performed in 265 patients (9,2%); the median of the time elapsed to the secondary definitive treatment was 3.5 months. With Cox regression analysis, significant correlation was revealed between the incidence of non-prosthetic treatment and younger age (year, HR = 0.977, p = 0.002), surgical delay (12-24 h vs 0-6 h, HR = 1.518, p = 0.023; 24h+ vs 0-6 h, HR = 1.372, p = 0.050), season of primary osteosynthesis (fall vs summer, HR = 0.636, p = 0.012), and type of femoral neck fracture (intracapsular displaced vs intracapsular undisplaced, HR = 1.340, p = 0,047). There was no significant effect of the day of primary surgery, the gender and the presence of co-morbidities on the incidence of further surgical interventions.

CONCLUSION

The summertime primary surgical intervention, delay of surgery longer than 12 h and type of femoral neck fracture are independent predictors of non-prosthetic further treatment of femoral neck fractures in elderly patients.

LEVEL OF EVIDENCE

Level IV, evidence from cohort studies.

Development and validation of a predictive nomogram for postoperative osteonecrosis of the femoral head with cannulated screws fixation

Background

Osteonecrosis of the femoral head (ONFH) remains a major complication of femoral neck fractures. Early interventions require preliminary prediction and detection. In this study, we aimed to evaluate the perioperative variables of postoperative ONFH in femoral neck fracture patients with closed reduction and cannulated screw fixation. We also established and validated an individualized nomogram for the prediction of postoperative ONFH.

Methods

We included 470 patients with ONFH from two hospitals [First Affiliated Hospital of University of Science and Technology of China (n=360) and Southern Branch of the First Affiliated Hospital of the University of Science and Technology of China (n=110)]. We evaluated the prognostic value of multiple perioperative variables using a Cox regression model in the training cohort. We developed a nomogram for the prediction of ONFH using a logistic regression model. We assessed the performance of this nomogram in a validation cohort and evaluated its clinical value.

Results

Of the 470 patients who met the inclusion criteria, 141 (30.0%) developed postoperative ONFH. We found alcohol use [odds ratio (OR), 1.743, 95% confidence interval (CI), 1.042-2.901, P=0.033], cerebrovascular disease (OR, 5.357, 95% CI, 2.318-13.13, P<0.001), interval to surgery (OR, 5.273, 95% CI, 2.724-10.43, P<0.001), Garden classification (OR, 23.17, 95% CI, 6.812-145.3, P<0.001), Garden index (OR, 5.935, 95% CI, 2.670-14.184, P<0.001), interval to partial weight-bearing (OR, 0.053, 95% CI, 0.006-0.296, P=0.002), and six-month Harris hip score (OR, 0.856; 95% CI, 0.792-0.919, P<0.001) were independent predictors of postoperative development of ONFH. Based on these variables, we developed a nomogram that showed good discrimination in both the training [area under the curve (AUC) =0.865] and the validation cohort (AUC =0.877). The favorable performance of this nomogram was also confirmed in the validation cohort.

Conclusions

We developed and validated an easy-to-use nomogram for predicting postoperative ONFH. This nomogram can aid decision-making of intraoperative interventions and postoperative rehabilitation plans for patients, surgeons, and osteo-rehabilitative physicians.

The diagnostic value of SPECT/CT in predicting the occurrence of osteonecrosis following femoral neck fracture: a prospective cohort study

Backgrounds

One of the most significant complications after a femoral neck fracture is osteonecrosis of the femoral head (ONFH). The concomitant use of single-photon emission computed tomography (SPECT) with computed tomography (CT) increases the sensitivity for detecting the anatomic location and severity of ONFH. In this study, we evaluated the diagnostic value of SPECT/CT for the occurrence of ONFH by quantifying the perfusion status of the femoral head.

Methods

A total of 30 patients who had multiple pinnings for femur neck fractures were included in this study. We classified the perfusion status into three groups: normal perfusion, decreased perfusion, and avascular groups, and compared the occurrence of femoral head necrosis between them. For quantitative analysis, we evaluated the uptake ratio of both femur heads (head-to-head uptake ratio). If the patient’s contralateral hip was incomparable, we measured the uptake ratio from the superior dome of the ipsilateral acetabulum (head-to-acetabulum uptake ratio).

Results

Twenty-four patients out of 30 achieved bone union, whereas the others developed ONFH. When the population was divided into intact and defective perfusion groups on scintigraphy, the sensitivity, specificity, and accuracy of the test were 83.3, 75.0, and 76.7%, respectively. The mean head-to-head uptake ratio value with a 95% confidence interval (CI) was 1.10 (95% CI: 0.85–1.36). In the osteonecrosis group, the mean value of the head-to-head uptake ratio was 0.33 (95% CI: 0.28–0.38). In contrast, the ratio was 1.30 (95% CI: 1.03–1.57) in the non-osteonecrosis group, demonstrating a significant difference in the uptake ratio (P < 0.001). When the cutoff value of the uptake ratio was set to 0.5, both the sensitivity and specificity were 100%. There was also a significant difference in the head-to-acetabulum uptake ratio between the two groups (P <  0.001).

Conclusions

SPECT/CT was useful in evaluating the perfusion status of the femoral head, showing high accuracy in predicting the occurrence of avascular necrosis. To demonstrate the reliability and validity of SPECT/CT, further prospective studies on a larger scale are warranted.

Efficacy of total hip arthroplasty for the treatment of patients with femoral head avascular necrosis: A protocol for systematic review and meta-analysis

BACKGROUND

Femoral head avascular necrosis (FHAN) is a very common condition among elderly population. Previous studies have reported that total hip arthroplasty (THAP) can benefit patients with such condition. However, no study systematically addressed this topic. Thus, this study will systematically explore the efficacy and safety of THAP for the treatment of patients with FHAN.

METHODS

We will search the following electronic bibliographic databases from inception to the February 29, 2020: MEDLINE, EMBASE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, China National Knowledge Infrastructure, and Chinese Scientific Journal Database. Randomized controlled trials of THAP for the treatment of patients with FHAN will be included, which were reported in any language. All process of study selection, data collection, and study quality assessment will be performed independently by 2 authors independently. Any divergences will be solved by discussion with another author. RevMan 5.3 software will be carried out for data synthesis and analysis.

RESULTS

This study will provide a detailed summary of current evidence related to the efficacy and safety of THAP for the treatment of patients with FHAN through assessing pain intensity of hip or knee joints, function and limitation of attacked femoral head, health-related quality of life, and complications.

CONCLUSION

The findings of this study may provide helpful guidance of THAP for the treatment of patients with FHAN.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202040067.

Guidelines for clinical diagnosis and treatment of osteonecrosis of the femoral head in adults (2019 version)

Osteonecrosis of the femoral head (ONFH) is a common and refractory disease in orthopaedic clinics. The number of patients with ONFH is increasing worldwide every year. There are an estimated 8.12 million patients with nontraumatic osteonecrosis in China alone. Treatment of nontraumatic osteonecrosis has always been a clinical challenge for orthopaedic surgeons. To further standardize diagnosis and treatment of ONFH, these guidelines provide not only basic diagnosis, treatment, and evaluation systems for ONFH but also expert advice and standards in many aspects, including epidemiology, aetiology, diagnostic criteria, pathological staging, prevention and treatment options, and postoperative rehabilitation. The aetiological factors of ONFH can currently be divided into two major categories: traumatic and nontraumatic; however, the specific pathological mechanism of ONFH is not completely clear. Currently, the staging system of ONFH formulated by the Association Research Circulation Osseous is widely used in clinical practice. Based on the changes in the intraosseous blood supply at different stages, the corresponding nonsurgical and surgical treatments are recommended, and when there are risk factors for possible ONFH, certain preventive measures to avoid the occurrence of osteonecrosis are recommended. These guidelines provide brief classification criteria and treatment regimen for osteonecrosis. Specification of the aetiology, treatment plan based on comprehensive consideration of the different stages of osteonecrosis, hip function, age, and occupation of the patients are important steps in diagnosis and developing treatment strategies.

TRANSLATIONAL POTENTIAL OF THIS ARTICLE

New advances in the epidemiology, etiology, pathophysiology, imaging, diagnosis and treatment of ONFH have been renewed in this revision. This guideline can be used for reference by orthopedic professionals and researchers, and for standardized diagnosis and treatment management under the clinical guidance, which is conducive to the prevention, treatment and further research of ONFH, improving the diagnosis and treatment level, making patients' symptoms under good control, and improving their quality of life.

Identification of potential miRNA biomarkers for traumatic osteonecrosis of femoral head

Traumatic osteonecrosis of femoral head (TONFH) is a common orthopedic disease caused by physical injury in hip. However, the unclear pathogenesis mechanism of TONFH and lacking of simple noninvasive early diagnosis method cause the necessity of hip replacement for most patients with TONFH. In this study, we aimed to identify circulating microRNAs (miRNAs) by integrated bioinformatics analyses as potential biomarker of TONFH. mRNA expression profiles were downloaded from the Gene Expression Omnibus database. Then we combined two miRNA screen methods: Weighted gene co-expression network analysis and fold change based differentially expressed miRNAs analysis. As a result, we identified 14 key miRNAs as potential biomarkers for TONFH. Besides, 302 target genes of these miRNAs were obtained and the miRNA-mRNA interaction network was constructed. Furthermore, the results of Kyoto Encyclopedia of Gene and Genome pathway analysis, Gene Ontology function analysis, protein-protein interaction (PPI) network analysis and PPI network module analysis showed close correlation between these 14 key miRNAs and TONFH. Then we established receiver operating characteristic curves and identified 6-miRNA signature with highly diagnosis value including miR-93-5p (area under the curve [AUC] = 0.93), miR-1324 (AUC = 0.92), miR-4666a-3p (AUC = 0.92), miR-5011-3p (AUC = 0.92), and miR-320a (AUC = 0.89), miR-185-5p (AUC = 0.89). Finally, the results of quantitative real-time polymerase chain reaction confirmed the significantly higher expression of miR-93-5p and miR-320a in the serum of patients with ONFH. These circulating miRNAs could serve as candidate early diagnosis markers and potential treatment targets of TONFH.

Complications After Pediatric Hip Fractures: Evaluation and Management

Pediatric proximal femur fractures are high-energy injuries with predictable and morbid complications. Osteonecrosis of the femoral head is the most common complication with identified risk factors including fracture type, patient's age, degree of displacement, timing to reduction, and stability of fixation. Additional complications include nonunion, coxa vara, and premature physeal arrest. The mainstay of treatment for traumatic pediatric osteonecrosis is hip preservation with total hip arthroplasty being reserved as a salvage procedure. An anatomic fracture reduction and a biomechanically stable construct are critical to prevent both nonunion and osteonecrosis. This review will look at the individual surgical interventions for the management of the associated complications of pediatric proximal femur fractures.

Efficacy of artificial femoral head replacement for femoral head avascular necrosis

BACKGROUND

Femoral head avascular necrosis (FHAN) is one of the most common progressive orthopedic disorders. Previous studies have reported that artificial femoral head replacement (AFHR) can effectively treat patients with FHAN. However, no systematic review has investigated the efficacy of AFHR for FHAN. This study will assess the efficacy of AFHR for patients with FHAN.

METHODS

We will search MEDLINE, EMBASE, Web of Science, Cochrane Library, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure up to March 1, 2019 without any restrictions. Any randomized controlled trials for assessing the efficacy of AFHR for patients with FHAN. The methodological quality for each eligible study will be assessed by using Cochrane risk of bias tool. Statistical analysis will be conducted by using RevMan 5.3.

RESULTS

This study will provide current evidence of AFHR for patients with FHAN from several aspects, including pain intensity, function, and limitation of femoral head, health-related quality of life, and safety.

CONCLUSION

This study will provide latest evidence on assessing the efficacy and safety of AFHR for FHAN.PROSPERO registration number: PROSPERO CRD42019126249.

Incidence and severity of femoral head avascularity after femoral neck or intertrochanteric fractures on preoperative bone single photon emission computed tomography/computed tomography: preliminary study

OBJECTIVE

The aim of the present study was to evaluate the incidence and degree of femoral head avascularity depending on the types of femoral neck or intertrochanteric fractures using preoperative bone single photon emission computed tomography (SPECT)/computed tomography (CT).

PATIENTS AND METHODS

A total of 131 patients with femoral neck or intertrochanteric fractures who underwent preoperative bone SPECT/CT were enrolled. Femoral head avascularity was evaluated using bone SPECT/CT images. Visual scores ranged from 1 to 5 based on visually assessed diagnostic confidence: 1=definitely avascular femoral head, 2=likely avascular, 3=equivocal, 4=likely not avascular, and 5=definitely not avascular. In quantitative analysis, contralateral, ipsilateral, and size ratios were measured.

RESULTS

Among 131 patients, 39 of 54 (72.22%) with femoral neck fractures and 23 of 77 (29.87%) with intertrochanteric fractures showed avascular femoral heads. The incidence of femoral head avascularity was significantly higher in patients with femoral neck fracture than those with intertrochanteric fracture. While the incidence and severity of femoral head avascularity increased with higher Garden stage in femoral neck fracture, neither was related to AO/Orthopaedic Trauma Association classification of intertrochanteric fracture. In addition, the number of bony fragments around intertrochanteric fractures was not a significant predictor of femoral head avascularity.

CONCLUSION

Although avascular femoral head on bone SPECT/CT does not directly indicate avascular necrosis, assessing the incidence and severity of femoral head avascularity using qualitative and quantitative parameters could give clinically useful information related to the classification. Additional studies with larger sample sizes would be a next step to expand the clinical role of bone SPECT/CT.

Factors associated with the development of avascular necrosis of the femoral head after non-displaced femoral neck fracture treated with internal fixation

OBJECTIVE

To identify the factors with influence on the development of avascular necrosis of the femoral head (ANFH) in patients with non-displaced femoral neck fractures treated with internal fixation.

MATERIAL AND METHOD

Retrospective study of cases and controls. We included non-displaced femoral neck fractures treated with internal fixation, and that presented ANFH with a postoperative follow-up of at least 2 years. The baseline variables, active comorbidities of the patients, the time for surgery and the number of screws used for osteosynthesis were recorded. Comparisons were made between the groups, those that presented ANFH and those that did not. By area under the curve, the cut-offs of age and time for surgery were located.

RESULTS

An association between sex, active comorbidities and number of screws used and the development of ANFH was not observed. The cut-off points for age and time for surgery were≤69 years and≤43hours, respectively. No significant correlation was observed for the cut-off time for surgery. In the multivariate analysis, age≤69 years was a significant predictor of the development of ANFH (OR 4.6; 95% CI 1.1 to 17.9; P=.028).

CONCLUSIONS

The patients aged 69 years or younger were at increased risk of developing ANFH after undisplaced femoral neck fracture treated with percutaneous screws.

Pediatric proximal femur fractures

Pediatric proximal femur fractures are rare injuries resulting from high-energy trauma. The Delbet classification is used when describing these injuries, and associates fracture type to the development of avascular necrosis. Historically, casting was utilized in the treatment of these injuries, but high complication rates following this approach have changed the treatment modality to early and anatomic fixation. Complications associated with these injuries including avascular necrosis, non-union, coxa-vara, and premature physeal fusion. Achieving anatomic reduction and performing internal fixation within 24 h from time of injury has become the standard of care in the treatment of pediatric proximal femur fractures.

Identifying Patients Who Will Most Benefit from Single Photon Emission Computerized Tomography and Computerized Tomography After Femoral Neck Fracture

Background

Single photon emission computerized tomography and computerized tomography (SPECT/CT) is useful for assessing blood supply within the femoral head after femoral neck fracture, but its use in all femoral neck fracture patients is not feasible. Therefore, the present study aimed to identify the patients for whom SPECT/CT examination will be most beneficial.

Material/Methods

Sixty-five patients with a unilateral femoral neck fracture who underwent SPECT/CT examination of the hip and were treated via closed reduction and internal fixation with three screws were enrolled between January 2009 and March 2011. A decision tree model (C 5.0) was used to identify the factors that best reflect blood supply and to build a flowchart for identifying patients who would benefit from SPECT/CT.

Results

Fracture type was most strongly associated with the Fracture/Normal (F/N) ratio, which reflects the blood supply to the fractured femoral head. Age and the time interval from injury to examination were also associated with the F/N ratio. SPECT/CT examination is most beneficial for patients with a displaced fracture, especially if they are over 58 years old and the time interval from injury to examination is less than 10 days.

Conclusions

Our results indicate that elderly people with a displaced fracture are most likely to benefit from SPECT/CT examination, which can show the blood supply to the femoral head within a relatively short window of time after the injury.

Dyslipidaemia for patients with low-energy femoral neck fractures after the treatment of cancellous screws: a retrospective study with a 3-year minimum follow-up

Background

Avascular necrosis of the femoral head (AVNFH) occurs infrequently following femoral neck fracture. The association between AVNFH and dyslipidaemia remains controversial. Although major risk factors for AVNFH have been proposed, most of them remain under discussion. Our purpose herein was to evaluate the association between dyslipidaemia and AVNFH following low-energy femoral neck fractures treated with cancellous screws in elderly patients in our tertiary care centre.

Methods

Four hundred and seventy-two consecutive patients (472 hips) with low-energy femoral neck fractures were identified and treated with cancellous screws from July 2007 to April 2013. Patients underwent evaluations preoperatively and each subsequent postoperative visit (months 1, 6, 12, 18, 24, 30, and 36). Clinical and radiographic evaluations were documented at each visit. The risk factors of AVNFH were assessed by multivariate binary logistic analysis.

Results

Follow-up was available for 277 patients, which included 135 patients diagnosed with AVNFH (AVNFH group) and 142 patients without AVNFH (control group). The median follow-up for patients alive at the time of analysis was 40 months (range, 37 to 46 months). The mean total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), and apolipoprotein B (Apo-B) values were considerably higher in the AVNFH group compared with those in the control group. The mean high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1(Apo-A1) values were significantly lower in the AVNFH group compared with those in the control group. A multivariate logistic backward regression model showed that HDL-C and LDL-C were the only variables associated with the development of postoperative AVNFH in patients with a femoral neck fracture (Odds ratio[OR] 33.09, 95% Confidence Interval[CI]: 2.65–19.42, p < 0.001 and OR 45.94, 95% CI: 0.47–27.75, p < 0.001, respectively).

Conclusion

Our results suggest that both low HDL-C and high LDL-C have a tendency to result in the occurrence of AVNFH in elderly patients with low-energy femoral neck fractures treated with cancellous screws.

The treatment of femoral neck fracture using VEGF-loaded nanographene coated internal fixation screws

Purpose

Previous studies have proved that vascular endothelial growth factor (VEGF) has a dual role in the promotion of new bone formation and blood vessel repair during fracture healing. However, how to introduce VEGF to a fracture site safely and effectively is still a challenge. This study aimed to prepare a VEGF-loaded nanographene coated internal fixation screw and to evaluate its effects in the treatment of femoral neck fracture.

Methods

Nanographene coated screws were prepared by direct liquid-phase exfoliation of the graphite method, and the surface characteristics were observed through scanning electron microscopy (SEM). VEGF was loaded on nanographene coatings through physical adsorption, and the VEGF controlled release was examined by ELISA. Then a canine femoral neck fracture model was built to examine both the angiogenic and osteogenic properties of the VEGF-loaded coated screws. X-ray, micro-CT-based microangiography, and histopathologic evaluation were used to assess the fracture healing progress.

Results

The results demonstrated that nanographene could load VEGF effectively, and the accumulative release of VEGF clearly increased during the entire testing period (9 days) without burst release. In canine fracture models, the results of X-ray, microangiography, and histopathologic examination proved that the speed of fracture healing, new bone formation area, and revascularization of the fractured femoral heads in the VEGF-loaded coated screws groups were significantly higher than in the control groups.

Conclusion

Our study proved that VEGF-loaded nanographene coated screws were effective in the treatment of femoral neck fracture and prevention of avascular necrosis of femoral head.

Focal osteonecrosis in the femoral head following stable anatomic fixation of displaced femoral neck fractures

INTRODUCTION

Femoral head (FH) osteonecrosis (ON) and subsequent segmental collapse is a major concern following displaced femoral neck fractures (FNF). We aimed to quantify residual perfusion to the FH following FNF and evaluate the viability of the FH overtime after surgical fixation.

MATERIALS AND METHODS

Twenty-three patients with FNF underwent dynamic contrast-enhanced (DCE)-MRI to estimate bone perfusion in the FH, using the contralateral side as control. Following open anatomic reduction and a length/angle-stable fixation, a special MRI sequence evaluated the FH for ON changes over time at 3 and 12 months after surgery.

RESULTS

We found significant compromise of both arterial inflow [83.1%-initial area under the curve (IAUC) and 73.8%-peak) and venous outflow (243.2%-elimination rate (K _el)] in the FH of the fractured side. The supero-medial quadrant suffered the greatest decrease in arterial inflow with a significant decrease of 71.6% (IAUC) and 68.5% (peak). Post-operative MRI revealed a high rate (87%-20/23) of small ON segments within the FH, and all developed in the anterior aspect of the supero-medial quadrants. Fracture characteristics, including subcapital FNF, varus deformity, posterior roll-off ≥20° and Pauwel's angle of 30°-50° demonstrated a greater decrease in perfusion compared to contralateral controls.

CONCLUSION

FNF significantly impaired the vascular supply to the FH, resulting in high incidence of small ON segments in the supero-medial quadrant of the FH. However, maintained perfusion, probably through the inferior retinacular system, coupled with urgent open anatomic reduction and stable fixation resulted in excellent clinical and radiographic outcomes despite a high rate of small ON segments noted on MRI.

LEVEL OF EVIDENCE

Level I: Prognostic Investigation.

Chinese Guideline for the Diagnosis and Treatment of Osteonecrosis of the Femoral Head in Adults

The treatment of adult osteonecrosis of the femoral head (ONFH), with 8.12 million patients in China, remains a challenge to surgeons. To standardize and improve the efficacy of the treatment of ONFH, Chinese specialists updated the experts' suggestions in March 2015, and an experts' consensus was given to provide a current basis for the diagnosis, treatment and evaluation of ONFH. The current guideline provides recommendations for ONFH with respect to epidemiology, etiology, diagnostic criteria, differential diagnosis, staging, treatment, as well as rehabilitation. Risk factors of non-traumatic ONFH include corticosteroid use, alcohol abuse, dysbarism, sickle cell disease and autoimmune disease and others, but the etiology remains unclear. The Association Research Circulation Osseous (ARCO) staging system, including plain radiograph, magnetic resonance imaging, radionuclide examination, and histological findings, is frequently used in staging ONFH. A staging and classification system was proposed by Chinese scholars in recent years. The major differential diagnoses include mid-late term osteoarthritis, transient osteoporosis, and subchondral insufficiency fracture. Management alternatives for ONFH consist of non-operative treatment and operative treatment. Core decompression is currently the most common procedure used in the early stages of ONFH. Vascularized bone grafting is the recommended treatment for ARCO early stage III ONFH. This guideline gives a brief account of principles for selection of treatment for ONFH, and stage, classification, volume of necrosis, joint function, age of the patient, patient occupation, and other factors should be taken into consideration.

Epiphyseal Arterial Network and Inferior Retinacular Artery Seem Critical to Femoral Head Perfusion in Adults With Femoral Neck Fractures

BACKGROUND

A better understanding of the blood supply of the femoral head is essential to guide therapeutic strategies for patients with femoral neck fractures. However, because of the limitations of conventional techniques, the precise distribution and characteristics of intraosseous arteries of the femoral head are not well displayed.

QUESTIONS/PURPOSES

To explore the characteristics and interconnections of the intraosseous vessel system between different areas of the femoral head and the possible blood supply compensatory mechanism after femoral neck fracture.

METHODS

The three-dimensional (3-D) structures of the intraosseous blood supply in 30 uninjured normal human femoral heads were reconstructed using angiography methods and microCT scans. The data were imported in the AMIRA^® and MIMICS^® software programs to reconstruct and quantify the extra- and intraosseous arteries (diameter, length). In a separate experiment, we evaluated the residual blood supply of femoral heads in 27 patients with femoral neck fractures before surgery by analyzing digital subtraction angiography data; during the study period, this was performed on all patients in whom hip-preserving surgery was planned, rather than arthroplasty. The number of affected and unaffected subjects included in the three groups (superior, inferior, and anterior retinacular arteries) with different types of fractures (Garden Types I-IV) were recorded and analyzed (Fisher's exact test) to reflect the affected degrees of these three groups of retinacular arteries in patients after femoral neck fractures.

RESULTS

The main results of our cadaver study were: (1) the main blood supply sources of the femoral head were connected by three main network structures as a whole, and the epiphyseal arterial network is the most widely distributed and the primary network structure in the femoral head; (2) the main stems of the epiphyseal arteries which were located on the periphery of the intraosseous vascular system have fewer anastomoses than the network located in the central region; (3) compared with the round ligament artery and anterior retinacular artery, the inferior retinacular artery has a relatively large caliber. Digital subtraction angiography of the 27 patients with hip fractures indicated that the inferior retinacular arterial system had a high likelihood of being unaffected after femoral neck fracture (100% [14 of 14] in nondisplaced fractures and 60% [six of 10] in Garden Type III fractures).

CONCLUSIONS

The epiphyseal arterial network and inferior retinacular arterial system appear to be two important structures for maintaining the femoral head blood supply after femoral neck fracture. Increased efforts to protect these key structures during surgery, such as drilling and placing internal implants closer to the central region of the femoral head, might be helpful to reduce the effect of iatrogenic injury of the intraosseous vascular system.

CLINICAL RELEVANCE

3-D anatomic evidence of intraosseous arterial distribution of the femoral head and the high frequency with which the inferior retinacular arteries remained patent after femoral neck fracture lead us to consider the necessity of drilling and placing internal implants closer to the central region of the femoral head during surgery. Future controlled studies might evaluate this proposition.

Three-year outcomes of intracapsular femoral neck fractures fixed with sliding hip screws in adults aged under sixty-five years

INTRODUCTION

Intracapsular femoral neck fractures remain associated with high rates of post-traumatic femoral head necrosis, non-union, and revision surgery.

AIM

Our aim was to identify factors associated with revision surgery in intracapsular femoral neck fractures treated with sliding hip screws (SHS) in adults aged <65 years.

PATIENTS AND METHODS

Consecutive admissions were identified retrospectively from the Royal Victoria Hospital, Belfast, which was the largest volume hospital on the National Hip Fracture Database. Of 2201 hip fractures between 1st August 2008 and 31st December 2010, 97 (4%) intracapsular fractures treated with SHS in adults <65 years were followed for a mean of 2.9 years (range 0-6.6).

RESULTS

Twenty-one (22%) hips were revised to arthroplasty. Avascular necrosis developed in 28 (29%) femoral heads. Eight (8%) fractures proceeded to non-union. Displaced fractures (p<0.001, Fisher's exact [FE]), posterior comminution (p=0.049, FE), chronic respiratory disease (p=0.006, FE) and residual distraction (p=0.011, χ²) were associated with revision to arthroplasty. Multiple regression found displaced fractures (p=0.006) and chronic respiratory disease (p=0.017) significant; in the latter 4 of 6 were revised (67%), including all four patients with chronic obstructive pulmonary disease (COPD). Eleven (11%) individuals required walking aids before injury, which rose to 34 (35%) at one year (p<0.0001, χ²). Eighty-nine (92%) individuals could walk alone outdoors before injury, but only 76 (78%) at one year (p=0.009, χ²).

CONCLUSIONS

Displaced fractures in individuals with chronic respiratory disease should be considered high risk for revision to arthroplasty. Posterior cortex deficiency should be evaluated prior to choice of operation. Fracture biology and revascularisation play a greater role than operation timing. A significant proportion of individuals do not recovery pre-morbid mobility by one year.

Risk Stratification for Avascular Necrosis of the Femoral Head After Internal Fixation of Femoral Neck Fractures by Post-Operative Bone SPECT/CT

PURPOSE

Avascular necrosis (AVN) of the femoral head is a major complication after internal fixation of a femoral neck fracture and determines the functional prognosis. We investigated postoperative bone single-photon emission computed tomography/computed tomography (SPECT/CT) for assessing the risk of femoral head AVN.

METHODS

We retrospectively reviewed 53 consecutive patients who underwent bone SPECT/CT within 2 weeks of internal fixation of a femoral neck fracture and follow-up serial hip radiographs over at least 12 months.

RESULTS

Nine patients developed femoral head AVN. In 15 patients who showed normal uptake on immediate postoperative SPECT/CT, no AVN occurred, whereas 9 of 38 patients who showed cold defects of the femoral head later developed AVN. The negative predictive value of immediate postoperative SPECT/CT for AVN was 100 %, whereas the positive predictive value was 24 %. Among 38 patients with cold defects, 1 developed AVN 3 months postoperatively. A follow-up bone SPECT/CT was performed in the other 37 patients at 2-10 months postoperatively. The follow-up bone SPECT/CT revealed completely normalized femoral head uptake in 27, partially normalized uptake in 8, and persistent cold defects in 2 patients. AVN developed in 3.7 % (1/27), 62.5 % (5/8), and 100 % (2/2) of each group, respectively.

CONCLUSIONS

According to the time point of imaging, radiotracer uptake patterns of the femoral head on postoperative bone SPECT/CT indicate the risk of AVN after internal fixation of femoral neck fractures differently. Postoperative bone SPECT/CT may help orthopedic surgeons determine the appropriate follow-up of these patients.

[Femoral neck fractures in young patients]

Femoral neck fractures in young patients are rare but of high clinical relevance due to the complexity of risk factors and complications. Early stabilization and accurate reduction are of high priority. Femoral head-preserving stabilization by dynamic hip screws or threefold screw osteosynthesis are the methods of choice. Postoperative results should be closely controlled in every case in order to be able to treat possible complications in time.

Assessment of Osteonecrosis in the Presence of Instrumentation for Femoral Neck Fracture Using Contrast-Enhanced MAVRIC Sequence

BACKGROUND

Evaluating postoperative femoral neck facture (FNF) with metal fixation hardware is commonly performed using radiographs. MRI has greater sensitivity and specificity to evaluate osteonecrosis (ON) but is often challenging due to the image distortion caused by metallic hardware.

QUESTIONS/PURPOSES

The aim of this study is to compare fast spin-echo (FSE) and multi-acquisition variable-resonance image combination (MAVRIC) sequences in assessing ON following metallic fixation of FNF and determining feasibility of semi-quantitative perfusion using MAVRIC.

METHODS

Radiography and MRI were performed at 3 and 12 months postoperatively, using FSE and pre- and post-gadolinium contrast MAVRIC sequences in 21 FNF patients. The presence and volume of ON were recorded. Signal intensity (SI) enhancement was measured on the MAVRIC sequences within the center and rim of ON; with the ilium and femoral diaphysis as controls. The detection rate of ON between MAVRIC and FSE images was evaluated as the difference of percent enhancement across the defined regions of interest.

RESULTS

ON was detected in 0% of radiographs, in 67% of FSE, and in 76% of MAVRIC images at 3 months follow-up, with similar results at 12 months. MAVRIC images had larger ON volume than FSE images at both time points. A significant percentage SI enhancement was only detected in the ON rim.

CONCLUSION

Radiographs could not detect ON following metallic fixation of FNF. MAVRIC is more sensitive than FSE for determining the volume of ON. SI measurements using MAVRIC may provide an indirect assessment of perfusion.

Vascular evaluation after cervical hip fractures in children: a case series of eight children examined by scintigraphy after surgery for cervical hip fracture and evaluated for development of secondary radiological changes

Femoral neck fractures in children and young adults are rare, but have a high risk of avascular necrosis (AVN) and subsequent gradual collapse of the femoral head. In 2006, we initiated the use of scintigraphy for the diagnosis of vascular impairment after a cervical fracture in children. In the present retrospective case study, we evaluated the effect of the remaining postoperative circulation in the femoral head after fracture in terms of the development of AVN and secondary degenerative changes of the hip joint. Eight children, four girls and four boys [mean age 11.5 years (7-16)], had been operated for a cervical or a basocervical hip fracture between 2006 and 2012. The femoral head circulation was evaluated postoperatively with scintigraphy and all children had been followed radiographically for a minimum of 1 year. The Ficat classification was used to stage the AVN and the Stulberg classification was used to stage the sphericity of the femoral head at follow-up. In two patients, the femoral head had normal circulation postoperatively and they also had normal radiographs at follow-up. In two patients, the entire femoral head was avascular postoperatively and at follow-up, one patient had normal radiographs and one had both subchondral sclerosis and flattening. These two patients had been treated with bisphosphonates and prolonged non-weight-bearing. Four patients had postoperatively retained circulation in parts of the femoral head. Three of these four patients had normal radiographs at follow-up. Evaluation of the remaining circulation after surgery may help to predict the outcome and guide the postoperative regime in children with a femoral neck fracture.

Anatomy, classification and treatment of intracapsular hip fractures

Hip fractures are increasingly common, given the increasing ageing, osteoporotic population with significant medical comorbidities. This review summarizes the anatomy of the proximal femur, reviews classification systems and gives recommendations for use of each treatment modality.

Proximal Femoral Fractures: What the Orthopedic Surgeon Wants to Know

Each year, more than 250,000 hip fractures occur in the United States, resulting in considerable patient mortality and morbidity. The various types of adult proximal femoral fractures require different treatment strategies that depend on a variety of considerations, including the location, morphologic features, injury mechanism, and stability of the fracture, as well as the patient's age and baseline functional status. The authors discuss femoral head, femoral neck, intertrochanteric, and subtrochanteric fractures in terms of injury mechanisms, specific anatomic and biomechanical features, and important diagnostic and management considerations, including the diagnostic utility of imaging modalities. The authors review clinically important classification systems, such as the Pipkin, Garden, Pauwels, and Evans-Jensen classification systems, with emphasis on differentiating subchondral insufficiency fractures from avascular necrosis of the femoral head and typical subtrochanteric fractures from atypical (often bisphosphonate-related) subtrochanteric fractures. In addition, the authors describe the potential complications and management strategies for each fracture type on the basis of the patient's age and physical condition. A clear understanding of these considerations allows the radiologist to better provide appropriate and relevant diagnostic information and management guidance to the orthopedic surgeon.

Treatment of neglected femoral neck fracture

Intra-capsular femoral neck fractures are seen commonly in elderly people following a low energy trauma. Femoral neck fracture has a devastating effect on the blood supply of the femoral head, which is directly proportional to the severity of trauma and displacement of the fracture. Various authors have described a wide array of options for treatment of neglected/nonunion (NU) femoral neck fracture. There is lack of consensus in general, regarding the best option. This Instructional course article is an analysis of available treatment options used for neglected femoral neck fracture in the literature and attempt to suggest treatment guides for neglected femoral neck fracture. We conducted the "Pubmed" search with the keywords "NU femoral neck fracture and/or neglected femoral neck fracture, muscle-pedicle bone graft in femoral neck fracture, fibular graft in femoral neck fracture and valgus osteotomy in femoral neck fracture." A total of 203 print articles were obtained as the search result. Thirty three articles were included in the analysis and were categorized into four subgroups based on treatment options. (a) treated by muscle-pedicle bone grafting (MPBG), (b) closed/open reduction internal fixation and fibular grafting (c) open reduction and internal fixation with valgus osteotomy, (d) miscellaneous procedures. The data was pooled from all groups for mean neglect, the type of study (prospective or retrospective), classification used, procedure performed, mean followup available, outcome, complications, and reoperation if any. The outcome of neglected femoral neck fracture depends on the duration of neglect, as the changes occurring in the fracture area and fracture fragments decides the need and type of biological stimulus required for fracture union. In stage I and stage II (Sandhu's staging) neglected femoral neck fracture osteosynthesis with open reduction and bone grafting with MPBG or Valgus Osteotomy achieves fracture union in almost 90% cases. However, in stage III with or without AVN, the results of osteosynthesis are poor and the choice of treatment is replacement arthroplasty (hemi or total).

Analysis of risk factors for femoral head necrosis after internal fixation in femoral neck fractures

Femoral head necrosis is a rare but devastating complication following femoral neck fracture. The reported incidence of avascular necrosis after femoral neck fracture fixation varies widely, and there is no consensus regarding its risk factors. The aim of this study was to analyze the risk factors for femoral head necrosis after internal fixation in femoral neck fracture. This retrospective study included 166 patients with femoral neck fractures treated with surgical reduction and internal fixation at the authors' institution from January 2004 to December 2008. Eight patients died for reasons unrelated to the surgery, and 12 patients were lost to follow-up. The remaining 146 patients (146 fractures) were followed until union or until conversion to total hip arthroplasty. The patients included 61 males and 85 females with an average age of 47.5 years (range, 18-68 years). The authors analyzed the following factors: age, sex, Garden classification, reduction quality, surgical methods, injury-to-surgery interval, preoperative traction, weight-bearing time, and implant removal. All patients were followed for a mean of 52 months (range, 6-90 months). The incidence of femoral head necrosis was 14.4% (21/146). Garden classification (P=.012), reduction quality (P=.008), implant removal (P=.020), and preoperative traction (P=.003) were significantly associated with femoral head necrosis. Patient age (P=.990), sex (P=.287), injury-to-surgery interval (P=.360), weight-bearing time (P=.868), and surgical methods (P=.987) were not significantly associated with femoral head necrosis. In multivariate logistic regression analysis, implant removal was not a significant risk factor for femoral head necrosis development (P=.498). Garden classification, reduction quality, and preoperative traction had a significant effect on femoral head necrosis development.

Regional analysis of femoral head perfusion following displaced fractures of the femoral neck

PURPOSE

To assess regional variations in the arterial and venous blood supply to the femoral head following displaced fracture of the femoral neck using dynamic contrast enhanced (DCE)-MRI quadrant analysis.

MATERIALS AND METHODS

A total of 27 subjects with displaced femoral neck fractures were enrolled in the study. Quadrant specific DCE-MRI perfusion analysis was performed on a 1.5 Tesla MRI scanner. Simultaneous imaging of control and displaced fractured hips was done for comparison.

RESULTS

Quadrant specific decreases were found in the arterial (A (0.52 versus 0.27; P = 5.7E-13), Akep (1.0/min(-1) versus 0.41/min(-1) ; P = 1.3E-9) and venous (kel (0.05/min(-1) versus -0.02/min(-1) ; P = 5.1E-5) supply to the femoral head between control and injured sides using a two-factor analysis of variance test. The fractional perfusion (initial area under the curve) in the supero/inferolateral quadrants was 49% min/54% min, in the supero/inferomedial quadrants was 43% min/46% min and for the total femoral head was 39% min on the fracture versus control sides.

CONCLUSION

Quadrant specific decreases in arterial and venous perfusion on the fracture side were observed when compared with control.

Logistic regression analysis of factors associated with avascular necrosis of the femoral head following femoral neck fractures in middle-aged and elderly patients

BACKGROUND

Risk factors for femoral neck fracture-induced avascular necrosis of the femoral head have not been elucidated clearly in middle-aged and elderly patients. Moreover, the high incidence of screw removal in China and its effect on the fate of the involved femoral head require statistical methods to reflect their intrinsic relationship.

METHODS

Ninety-nine patients older than 45 years with femoral neck fracture were treated by internal fixation between May 1999 and April 2004. Descriptive analysis, interaction analysis between associated factors, single factor logistic regression, multivariate logistic regression, and detailed interaction analysis were employed to explore potential relationships among associated factors.

RESULTS

Avascular necrosis of the femoral head was found in 15 cases (15.2 %). Age × the status of implants (removal vs. maintenance) and gender × the timing of reduction were interactive according to two-factor interactive analysis. Age, the displacement of fractures, the quality of reduction, and the status of implants were found to be significant factors in single factor logistic regression analysis. Age, age × the status of implants, and the quality of reduction were found to be significant factors in multivariate logistic regression analysis. In fine interaction analysis after multivariate logistic regression analysis, implant removal was the most important risk factor for avascular necrosis in 56-to-85-year-old patients, with a risk ratio of 26.00 (95 % CI = 3.076-219.747).

CONCLUSION

The middle-aged and elderly have less incidence of avascular necrosis of the femoral head following femoral neck fractures treated by cannulated screws. The removal of cannulated screws can induce a significantly high incidence of avascular necrosis of the femoral head in elderly patients, while a high-quality reduction is helpful to reduce avascular necrosis.

The effects of autologous bone marrow mesenchymal stem cell arterial perfusion on vascular repair and angiogenesis in osteonecrosis of the femoral head in dogs

PURPOSE

The purpose of this study was to observe the effects of marrow mesenchymal stem cell (MSCs) arterial perfusion on vascular repair and angiogenesis in osteonecrosis of the femoral head (ONFH).

METHODS

Twelve healthy male adult Beagle dogs were randomly divided into two groups: group A (the control group) and group B (the MSCs arterial perfusion group). ONFH animal models were established by hip dislocation and liquid nitrogen. At the same time, MSCs were obtained, cultured and proliferated. After three weeks, arterial perfusion was performed in all animals. Group B was given 1 ml MSCs (5 × 10(6)-1 × 10(7)/ml), while 0.9 % normal saline was used in group A. After four weeks or eight weeks, the dogs were put to death. The changes of main arteries, the expression of vascular endothelial growth factor (VEGF), VEGF mRNA and microvessel density (MVD) of ONFH were observed. All the data were analysed by SPSS13.0.

RESULTS

In digital subtraction angiography (DSA), after four or eight weeks of treatment, the quantity and diameter of the main arteries of the femoral head in group B were improved, compared to group A (P < 0.05,P < 0.01). Concerning histology and immunohistochemistry, after four or eight weeks of treatment, the expression of VEGF and MVD were significantly higher than that of group A (P < 0.05, P < 0.01). For real-time quantitative polymerase chain reaction (RT-PCR), after four or eight weeks of treatment, the expression of VEGF mRNA in group B was significantly higher than that of group A (P < 0.05, P < 0.01), and after eight weeks of treatment, the expression of VEGF mRNA were significantly higher than that of four-weeks treatment in group A (P <0.01).

CONCLUSIONS

MSCs arterial perfusion can promote vascular repair and angiogenesis and then improve blood supply and repair of femoral head.