Avascular necrosis of the femoral head after femoral neck fracture

Does capsulotomy in closed reduction of garden type 3 femoral neck fractures decrease incidence of avascular necrosis? A randomized controlled trial

BACKGROUND

Femoral neck fractures, pose significant risks of AVN and non-union. Recent studies suggest that adding capsulotomy to CRIF could reduce complications by alleviating intracapsular pressure and enhancing femoral head vascularity. This study aims to assess the efficacy of capsulotomy combined with CRIF in reducing the incidence of AVN and non-union in Garden III femoral neck fractures compared to CRIF alone.

METHODS

Participants aged 18-55 with Garden III femoral neck fractures were randomly assigned to either the CRIF-only group or the CRIF with capsulotomy group. Outcomes included rates of AVN and non-union, assessed at 3 and 6 months postoperatively. Functional outcomes were measured using the Harris Hip Score (HHS).

RESULTS

67 patients were included, with 32 in the capsulotomy group and 35 in the CRIF-only group. The capsulotomy group demonstrated significantly lower rates of AVN (6.25% vs. 11.4%) and non-union (0% vs. 5.7%) compared to the CRIF-only group. Additionally, the capsulotomy group achieved a significantly higher mean HHS at 3 months, indicating improved functional outcomes.

CONCLUSION

Adding capsulotomy to CRIF in the management of Garden III femoral neck fractures may reduce complications, specifically AVN and non-union, and enhance functional recovery. The combination of randomization and blinding methods in this study underscores the reliability of these findings, supporting capsulotomy as a potentially beneficial adjunct to CRIF in specific fracture patterns.

Hip arthroscope-assisted percutaneous reduction and fixation of displaced subcapital femoral neck fracture

Reduction quality is associated with fracture prognosis. Displaced subcapital femoral neck fracture has highest possibility of avascular necrosis of femoral head and non-union among the femoral neck fractures, which commonly necessitate revisions or hip replacement. This study introduces for the first time of using hip arthroscope to directly visualize and assist the reduction of displaced subcapital femoral neck fracture when closed reduction is unsatisfactory. Due to the minimally invasive advantage of arthroscopic assistance, radiation exposure or intraoperative bleeding can be reduced, open reduction is avoided so that the blood supply of femoral head can be preserved. Through direct visualization, the complete removal of hematoma and fracture debris can be achieved, which is not possible with closed reduction, and can potentially reduce the risk of non-union during bone healing.

Femoral neck system (FNS) versus 4 cannulated compression screws (CCSs) in the treatment of young patients with Pauwels type III femoral neck fracture: a retrospective comparative study

OBJECTIVE

This study aimed to evaluate the clinical effectiveness of the femoral neck system (FNS) compared to four cannulated compression screws (CCSs) for managing Pauwels type III femoral neck fractures in young patients.

METHODS

A retrospective analysis was conducted on young patients with Pauwels type III femoral neck fractures treated at our hospital from January 2021 to December 2022. Patients were categorized into two groups based on their respective internal fixation methods: the FNS group (32 cases) and the CCSs group (41 cases). Various demographic and clinical variables, including age, gender, fracture side, mechanism of injury, Garden classification, and time interval between injury and surgery, were collected. Comparisons were made between the two groups regarding operative duration, intraoperative blood loss, length of hospital stay, hospitalization expenses, time to fracture healing, and Harris hip score at one year post-surgery. Additionally, postoperative complications such as wound infections, nonunion, femoral neck shortening, avascular necrosis of the femoral head, and hardware failure were analyzed. Follow-up duration ranged from 12 to 24 months for all patients.

RESULTS

There were no significant differences between the FNS and CCSs groups in terms of demographic characteristics, fracture characteristics, time to fracture healing, duration of hospital stay, and Harris hip score at one year post-surgery (p > 0.05). However, the CCSs group exhibited significantly shorter operative time, reduced intraoperative blood loss, and lower hospitalization costs compared to the FNS group (p < 0.05). Patients treated with FNS had longer operative durations (82.33 ± 28.85 min vs. 66.58 ± 14.38 min, p = 0.006), higher blood loss (106.67 ± 65.83 mLvs.70.00 ± 27.39 mL, p < 0.001), and increased hospitalization expenses (58,345.98 ± 3706.57 RMB vs. 35,427.63 ± 3019.30 RMB, p < 0.0001). The incidence of postoperative complications was 21.8% in the FNS group and 26.8% in the CCSs group (p > 0.05), with no significant differences observed in the rates of wound infections, femoral neck shortening, femoral head necrosis, nonunion, and hardware failure between the two groups (p > 0.05).

CONCLUSION

In the management of Pauwels type III femoral neck fractures in young patients, FNS demonstrates clinical efficacy comparable to CCSs. However, considering factors such as operative time, intraoperative blood loss, and hospitalization costs, CCSs may be preferred.

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.

The small screw-apex distance is potentially associated with femoral head osteonecrosis in adults with femoral neck fractures treated by closed reduction and percutaneous 3 parallel cannulated screws

OBJECTIVE

Femoral neck fractures (FNFs) are among the most common fractures in elderly individuals. Surgery is the main treatment for FNFs, and osteonecrosis of the femoral head (ONFH) is one of the unacceptable complications. This study aimed to assess both the clinical and radiological outcomes in patients with FNFs treated with three parallel cannulated screws and to identify relationship between screws position and ONFH.

PATIENTS AND METHODS

A total of 100 patients who were treated with closed reduction and fixed with 3 parallel cannulated screws met the inclusion criteria between January 2014 and December 2020 at authors' institution. The follow-up duration, age, sex, affected side, and injury-to-surgery interval were collected; the neck-shaft angle of both hips, screw-apex distance (SAD) and the tip-apex distance (TAD)were measured; and the Garden classification, quality of reduction and presence of ONFH were evaluated.

RESULTS

The sample consisted of 37 males and 63 females, with 60 left and 40 right hips affected. The mean age of patients was 54.93 ± 12.24 years, and the mean follow-up was 56.3 ± 13.38 months. The overall incidence of ONFH was 13%. No significant difference was observed in the incidence of ONFH by affected side, age, fracture displacement, injury-to-surgery interval, neck-shaft angle deviation, or reduction quality. The SAD was significantly shorter in ONFH patients than in normal patients for all three screws (p = 0.02, 0.02, and 0.01, respectively).

CONCLUSIONS

The short SAD of all screws is associated with femoral head necrosis of FNFs treated with 3 cannulated screws. The short SAD indicated that screws malpositioning in the weight-bearing area of the femoral head, potentially harming the blood supply and compromising the anchorage of the primary compressive trabeculae in this region.

Non-traumatic osteonecrosis of the femoral head induced by steroid and alcohol exposure is associated with intestinal flora alterations and metabolomic profiles

OBJECTIVE

Osteonecrosis of the femoral head (ONFH) is a severe disease that primarily affects the middle-aged population, imposing a significant economic and social burden. Recent research has linked the progression of non-traumatic osteonecrosis of the femoral head (NONFH) to the composition of the gut microbiota. Steroids and alcohol are considered major contributing factors. However, the relationship between NONFH caused by two etiologies and the microbiota remains unclear. In this study, we examined the gut microbiota and fecal metabolic phenotypes of two groups of patients, and analyzed potential differences in the pathogenic mechanisms from both the microbial and metabolic perspectives.

METHODS

Utilizing fecal samples from 68 NONFH patients (32 steroid-induced, 36 alcohol-induced), high-throughput 16 S rDNA sequencing and liquid chromatography with tandem mass spectrometry (LC-MS/MS) metabolomics analyses were conducted. Univariate and multivariate analyses were applied to the omics data, employing linear discriminant analysis effect size to identify potential biomarkers. Additionally, functional annotation of differential metabolites and associated pathways was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Subsequently, Spearman correlation analysis was employed to assess the potential correlations between differential gut microbiota and metabolites.

RESULTS

High-throughput 16 S rDNA sequencing revealed significant gut microbial differences. At the genus level, the alcohol group had higher Lactobacillus and Roseburia, while the steroid group had more Megasphaera and Akkermansia. LC-MS/MS metabolomic analysis indicates significant differences in fecal metabolites between steroid- and alcohol-induced ONFH patients. Alcohol-induced ONFH (AONFH) showed elevated levels of L-Lysine and Oxoglutaric acid, while steroid-induced ONFH(SONFH) had increased Gluconic acid and Phosphoric acid. KEGG annotation revealed 10 pathways with metabolite differences between AONFH and SONFH patients. Correlation analysis revealed the association between differential gut flora and differential metabolites.

CONCLUSIONS

Our results suggest that hormones and alcohol can induce changes in the gut microbiota, leading to alterations in fecal metabolites. These changes, driven by different pathways, contribute to the progression of the disease. The study opens new research directions for understanding the pathogenic mechanisms of hormone- or alcohol-induced NONFH, suggesting that differentiated preventive and therapeutic approaches may be needed for NONFH caused by different triggers.

Perfusion Imaging of the Musculoskeletal System

Perfusion imaging is the aspect of functional imaging, which is most applicable to the musculoskeletal system. In this review, the anatomy and physiology of bone perfusion is briefly outlined as are the methods of acquiring perfusion data on MR imaging. The current clinical indications of perfusion related to the assessment of soft tissue and bone tumors, synovitis, osteoarthritis, avascular necrosis, Keinbock's disease, diabetic foot, osteochondritis dissecans, and Paget's disease of bone are reviewed. Challenges and opportunities related to perfusion imaging of the musculoskeletal system are also briefly addressed.

Avascular Necrosis of the Femoral Head Following Intramedullary Nailing of a Femoral Shaft Fracture in a Skeletally Mature Adult: A Case Report

Avascular necrosis (AVN) of the femoral head is a well-documented complication that occurs following femoral neck fractures in both adults and pediatrics. Incidence of AVN following intramedullary nailing (IMN) for femoral shaft fractures is relatively rare. We are reporting an exceptional case of a 28-year-old skeletally mature adult, with no risk factors, who developed stage 3 AVN following trochanteric entry-point IMN for a traumatic femur shaft fracture. Our case contributes to the existing literature by adding to the limited number of reported cases available. In addition, it emphasizes the importance of observation and anticipation for such complications and shows the need for further studies to understand the relationship between this modality of treatment and the development of AVN of the femoral head.

"Mulligan Bent Leg Raise" Technique in Avascular Necrosis

This case report examines the effectiveness of the "Mulligan bent leg raise" (MBLR) method for treating femoral head avascular necrosis (AVN). A professional physiotherapist directed a six-week rehabilitation program for a 37-year-old male patient with AVN that included this innovative physiotherapeutic method. According to radiographic results and standardized evaluations, the patient showed significant improvements in hip range of motion, functional ability, and pain levels. As a viable supplement to conventional rehabilitation techniques, the MBLR method has shown promise in improving joint function and reducing symptoms in individuals with acute compartment syndrome. The present study provides significant contributions to the discipline. It highlights the necessity for more investigation to examine the wider relevance and enduring effectiveness of this methodology in various population affected.

Characteristics and Treatment Strategies for Basicervical and Transcervical Shear Fractures of the Femoral Neck

This study aimed to define basicervical and transcervical shear fractures using area classification and to determine the optimal osteosynthesis implants for them. The clinical outcomes of 1042 proximal femur fractures were investigated. A model of the proximal femur of a healthy adult was created from computed tomography images, and basicervical and transcervical shear fractures were established in the model. Osteosynthesis models were created using a short femoral nail with a single lag screw or two lag screws and a long femoral nail with a single lag screw or two lag screws. The minimum principal strains of the fracture surfaces were compared when the maximum loads during walking were applied to these models using finite element analysis software. Basicervical fractures accounted for 0.96% of all proximal femur fractures, 67% of which were treated with osteosynthesis; the failure rate was 0%. Transcervical shear fractures accounted for 9.6% of all proximal femur fractures, 24% of which were treated with osteosynthesis; the failure rate was 13%. Finite element analysis showed that transcervical shear fracture has high instability. To perform osteosynthesis, multiple screw insertions into the femoral head and careful postoperative management are required; joint replacement should be considered to achieve early mobility.

Comparing the volume of vascular intersection of two femoral neck fracture fixation implants using an In silico technique

Femoral neck fracture displacement with subsequent vascular disruption is one of the factors that contribute to trauma-induced avascular necrosis of the femoral head. Iatrogenic damage of the intraosseous arterial system during fixation of femoral neck fracture is another possible cause of avascular necrosis that is less well understood. Recently, Zhao et al (2017) reconstructed 3D structures of intraosseous blood supply and identified the epiphyseal and inferior retinacular arterial system to be important structures for maintaining the femoral head blood supply after femoral neck fracture. The authors therefore recommended placing implants centrally to reduce iatrogenic vascular injuries. Our in vitro study compared the spatial footprint of a traditional dynamic hip screw with an antirotation screw versus a newly developed hip screw with an integrated antirotation screw on intraosseous vasculature.

Methods

Three dimensional (3D) µCT angiograms of 9 cadaveric proximal femora were produced. Three segmented volumes-porous or cancellous bone, filled or cortical bone, and intraosseous vasculature-were converted to surface files. 3D in silico models of the fixation systems were sized and implanted in silico without visibility of the vascular maps. The volume of vasculature that overlapped with the devices was determined. The ratio of the vascular intersection to the comparator device was calculated, and the mean ratio was determined. A paired design, noninferiority test was used to compare the devices.

Results

Results indicate both significant (P < 0.001) superiority and noninferiority of the hip screw with an integrated antirotation screw when compared with a dynamic hip screw and antirotation screw for the volume of vasculature that overlapped with each device in the femoral neck.

Conclusions

Combining established methods of vascular visualization with newer methods enables an implant's impact on vascular intersection to be assessed in silico. This methodology suggests that when used for femoral neck fracture management, the new device intersects fewer blood vessels than the comparator. Comparative clinical studies are needed to investigate whether these findings correlate with the incidence of avascular necrosis and clinical outcomes.

The incidence of focal osteonecrosis of the femoral head and its impact on conversion hip arthroplasty after screw fixation of femoral neck fractures: a multicenter retrospective study based on postoperative magnetic resonance imaging

PURPOSE

Osteonecrosis of the femoral head (ONFH) and subsequent head collapse is a major concern after internal fixation of femoral neck fracture (FNF). Previous studies focused on ONFH incidence using plain radiography; postoperative magnetic resonance imaging (MRI) was rarely performed. We performed a multicenter retrospective study to investigate the incidence of ONFH and the need for conversion hip arthroplasty after FNF screw fixation.

METHODS

We reviewed 195 patients who underwent screw fixation during closed FNF reduction between 2012 and 2017 at three institutions. Except for patients who did not consent to MRI, all patients underwent postoperative MRI either 1-3 years after screw fixation. The occurrence of ONFH was investigated through plain radiography and MRI.

RESULTS

Thirty patients were diagnosed with ONFH through plain radiography, and an additional 33 patients were diagnosed with MRI, resulting in a total of 63 patients (32.3%) diagnosed with ONFH. The mean time to ONFH diagnosis was 18.9 months and the conversion rate to hip arthroplasty was 10.2%. Of the 33 patients who were normal on hip radiography but exhibited ONFH on MRI, all had small focal lesions not associated with head collapse at the last follow-up. The ONFH group diagnosed through plain radiography had more unstable FNFs than the group diagnosed through MRI.

CONCLUSION

Although postoperative MRI revealed a higher incidence of ONFH after FNF screw fixation than reported previously, the small focal MRI lesions were not associated with increased risks of femoral head collapse or conversion to arthroplasty.

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.

Hidden osteonecrosis of the femoral head after healed femoral neck fractures: magnetic resonance imaging study of 58 consecutive patients

INTRODUCTION

Several studies investigated the posttraumatic osteonecrosis of the femoral head (ONFH) after femoral neck fracture (FNF). However, no study has investigated the hidden ONFH after FNF, which is missed by simple radiographs, using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

This retrospective study involved 58 consecutive patients who underwent implant removal surgery after internal fixation due to FNF. MRI was used to investigate the incidence of hidden ONFHs, which were not initially revealed on plain radiographs. The comparisons between hidden ONFH and other groups were performed for patent demographics and clinical variables including ONFH location, lesion size, the progression rate of ONFH collapse, and end-stage arthroplasty conversion rate.

RESULTS

Of the 58 patients, 38 exhibited no evidence of ONFH on plain radiograph screening. However, 13 of the 38 patients were confirmed of hidden ONFH via MRI. The collapse progressed in four of the 13 patients, and one of them underwent total hip arthroplasty surgery. No significant differences were found between the hidden and definite ONFH groups in demographics and clinical variables. However, a significant difference exists between the hidden ONFH and the normally healed FNF groups in terms of the Garden type (P < 0.001).

CONCLUSIONS

A large number of cases with hidden ONFH were confirmed using MRI following healed FNF, and most of them were initially displaced FNF. Thus, the treatment method between internal fixation and hip arthroplasty should be carefully selected, particularly with displaced FNF.

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.

Value of SPECT/CT in the diagnosis of avascular necrosis of the head of femur: A meta-analysis

INTRODUCTION

To evaluate the diagnostic value of single photon emission computed tomography/computed tomography (SPECT/CT) in patients with avascular necrosis (AVN) of the femoral head.

METHODS

A search of the databases PubMed, ScienceDirect, and Google Scholar was undertaken using targeted index word. Studies satisfying inclusions and exclusions criteria were identified and additional related literature sources were considered. Analysis included pooled sensitivity and specificity, odds ratio (OR), and receiver operating characteristic (ROC) analysis.

RESULTS

Seven studies were identified that specifically related to the diagnostic accuracy of SPECT/CT in the detection or characterisation of AVN of the femoral head. These were included in the meta-analysis. The pooled sensitivity and specificity were 94% (95% confidence interval of 87-97%) and 75% (95% confidence interval of 68-81%) respectively, the OR was 44.5 (with a 95% confidence interval of 18.2-108.6), and the area under the SROC was 93.73% (with a 95% confidence interval of 89.2%-98.3%).

CONCLUSION

This meta-analysis provides strong evidence of the high diagnostic efficacy of SPECT/CT in the evaluation of AVN of the femoral head.

IMPLICATIONS FOR PRACTICE

In the absence of or contraindication to MRI, SPECT/CT is able to provide a suitable alternative for diagnosis of AVN of the head of femur.

Changes in radiological parameters during reduction of femoral neck fractures: A radiographic evaluation of cadavers

OBJECTIVE

To investigate changes in the Garden index and other radiological parameters during reduction of femoral neck fractures.

METHODS

Ten healthy, human femoral specimens were obtained. A 2.0 mm diameter Kirschner wire was implanted in the centre of the femoral head. A perpendicular osteotomy was made in the middle of the femoral neck. The distal osteotomy surface was used as the angle of rotation (pronation and supination up to 90° at 10° intervals). Anterior-posterior and lateral view radiographs were taken at different angles. The Garden index and other relevant data were analysed using the picture archiving and communication system. Changes in the area of the femoral head fovea at different rotation angles were measured.

RESULTS

There were no significant differences in the Garden index between 0-30° of pronation and supination (p > .05). For angles of 40-90°, there were statistically significant differences in the Garden index (p < .05). The area of femoral head fovea decreased with increasing pronation angle, and increased with increasing supination angle.

CONCLUSIONS

The Garden index does not change significantly if the angle of fracture rotation is 0-30° (in either pronation or supination) during femoral neck fracture reduction. Therefore, it is impossible to judge the rotation of fracture in this range of angles. The Garden index can detect the rotation of fracture for rotation angles of 40-90° (in either pronation or supination). Changes in the area of the femoral head fovea can help determine the rotation of femoral neck fractures.

LEVEL OF EVIDENCE

Level V.

Neglected Neck of Femur Fracture Managed by Surgical Hip Dislocation: A Case Report and Literature Review

Introduction

Femoral neck fractures (FNFs) in young adults are relatively uncommon emergency that requires early diagnosis and management possible to prevents joint complications.

Case Report

A 24-year-old male presented with a right hip pain for 3 months after a heavy physical exercise during military training. The imaging exhibited a transcervical FNF with displacement and a potential of avascular necrosis (AVN). The patient was managed by Open reduction and internal fixation through surgical hip dislocation (SHD) and bone grafting from the right iliac bone. The patient returned to his full military services 14 weeks following the surgery and was followed for 3 years without any symptomatic or functional problems.

Conclusion

SHD could be one of the surgical options hired in the management of late presentations of FNFs in young adults with high suspicion of AVN.

Combination of CRP with NLR is a sensitive tool for screening fixation-related infection in patients undergoing conversion total hip arthroplasty after failed internal fixation for femoral neck fracture

AIMS

Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture.

METHODS

We retrospectively included 340 patients who underwent conversion THA after internal fixation for femoral neck fracture from January 2008 to September 2020. Those patients constituted two groups: noninfected patients and patients diagnosed with FRI according to the 2013 International Consensus Meeting Criteria. Receiver operating characteristic (ROC) curves were used to determine maximum sensitivity and specificity of these two preoperative ratios. The diagnostic performance of the two ratios combined with preoperative CRP or ESR was also evaluated.

RESULTS

The numbers of patients with and without FRI were 19 (5.6%) and 321 (94.4%), respectively. Areas under the ROC curve for diagnosing FRI were 0.763 for MLR, 0.686 for NLR, 0.905 for CRP, and 0.769 for ESR. Based on the Youden index, the optimal predictive cutoffs were 0.25 for MLR and 2.38 for NLR. Sensitivity and specificity were 78.9% and 71.0% for MLR, and 78.9% and 56.4% for NLR, respectively. The combination of CRP with MLR showed a sensitivity of 84.2% and specificity of 94.6%, while the corresponding values for the combination of CRP with NLR were 89.5% and 91.5%, respectively.

CONCLUSION

The presence of preoperative FRI among patients undergoing conversion THA after internal fixation for femoral neck fracture should be determined. The combination of preoperative CRP with NLR is sensitive tool for screening FRI in those patients. Cite this article: Bone Joint J 2021;103-B(9):1534-1540.

Inhibition of miR-93-5p promotes osteogenic differentiation in a rabbit model of trauma-induced osteonecrosis of the femoral head

Trauma‐induced osteonecrosis of the femoral head (TIONFH) is characterized by femoral head collapse accompanied by degenerative changes of the hip. We previously reported that miR‐93‐5p expression is abnormally high in patients with TIONFH, but the role of miR‐93‐5p in the TIONFH process remains unclear. Herein, we investigated the role of miR‐93‐5p in TIONFH in a rabbit model. Bone marrow mesenchymal stem cells (BMSCs) were used for both in vivo and in vitro experiments. A rabbit model of TIONFH was injected with BMSCs transfected with miR‐93‐5p inhibitor. In addition, both an miR‐93‐5p mimic and negative control were transfected into BMSCs. Expression of miR‐93‐5p was significantly increased in the model group compared with control samples. An miR‐93‐5p inhibitor induced the expression of bone morphogenetic protein 2 (BMP‐2) and alkaline phosphatase. Furthermore, expression of osteogenesis‐related markers (BMP‐2, secreted phosphoprotein 1, RUNX family transcription factor 2 and Osterix) was higher in the miR‐93‐5p inhibitor group, as revealed by quantitative PCR and western blotting. In addition, in vitro experimentation revealed that an miR‐93‐5p mimic decreased BMP‐2 and TNF receptor superfamily member 11b expression, but increased receptor activator of nuclear factor‐kappaB ligand expression. In summary, the miR‐93‐5p inhibitor could promote osteogenic differentiation by increasing BMP‐2 expression during the development of TIONFH. Thus, miR‐93‐5p may have potential as a therapeutic target for TIONF treatment.

Cell therapy for post-traumatic hip osteonecrosis in young patients

PURPOSE

To investigate the effects of mesenchymal stem cells injections for treatment of post-traumatic osteonecrosis of the femoral head.

METHODS

A total of 46 patients were eligible and enrolled in the study. Twenty-three patients were treated with cell therapy and 23 patients with hip arthroplasty (control group). During a minimum follow-up duration of 10years, radiographs were used to evaluate the radiological results, and the Harris Hip Score (HHS) and visual analog scale were chosen to assess the clinical results.

RESULTS

For the cell therapy group, the product obtained by bone marrow aspiration in the iliac crest before concentration had a mean value of 2480 MSCs/mL (range 730 to 3800). The concentration product was containing average 9300 MSCs/mL (range 3930 to 19,800). At the most recent follow-up (average 15years after the first surgery, range 10 to 20years), among the 23 hips treated with cell therapy (concentrate bone marrow), 6 hips (26%) had collapsed and had required total hip arthroplasty (THA) without revision. Among the 23 hips treated with a primary THA, 7 (30.4%) had required one revision (second THA) at a mean follow-up of 6years (range 1 to 12years); two of these 7 hips had a re-revision; principal causes of revision were recurrent dislocations (3 cases) aseptic loosening (3 revisions) and infection (1 revision). As consequence, we observed significant (P<0.01) better survival time before revision for the cell therapy group. Better results with cell therapy were obtained for treatment at early stages before collapse.

CONCLUSION

The present study has demonstrated encouraging effects of cell therapy in early post-traumatic hip osteonecrosis and provides another choice for treatment in early stages I to II.

Osteonecrosis of the distal tibia after pilon fractures

BACKGROUND

Pilon fractures are devastating injuries with high complication rates. Osteonecrosis has been previously described after Weber C fracture-dislocations but has not been reported following fixation of pilon fractures.

METHODS

All AO/OTA 43-C pilon fractures from 2007 to 2018 were reviewed. Injury factors and demographics were recorded. Computed tomography (CT) scans of the fracture pattern were analyzed to determine risk factors for ON.

RESULTS

71 pilon fractures in 69 patients were included. Mean follow-up was 21.6 months. 18 patients demonstrated ON at a mean 7.3 months' post-injury. Regression analysis demonstrated no differences between cohorts with respect to smoking status, open injury, or diabetic status. ON was associated with small anterolateral fragment less than 2.0cm² (OR=19.47, p=0.012), higher comminution (OR=3.00, p=0.005), use of calcium phosphate bone substitute (OR=20.72, p=0.013).

CONCLUSIONS

ON of the distal tibia was not associated with patient factors but was associated with fracture characteristics.

High incidence of "in-out-in" posterosuperior screws after cannulated screw fixation of femoral neck fractures

INTRODUCTION

Cadaveric models have demonstrated a high incidence of extraosseous "in-out-in" (IOI) posterosuperior screws after cannulated screw fixation of femoral neck fractures. The purpose of this study was to determine the incidence of IOI screws in vivo and to evaluate their association with osteonecrosis and revision surgery.

METHODS

A total of 104 patients with 107 hips with a pelvis computed tomography (CT) scan after cannulated screw fixation of a femoral neck fractures were included. Screw position was evaluated on postoperative radiographs and CT scan to determine if screws were IOI or all-in. Osteonecrosis and revision surgeries were documented.

RESULTS

IOI posterosuperior screws were identified on CT scan in 58 (54%) hips. On postoperative AP and lateral radiographs, IOI screws were a median (interquartile range) of 10 mm (7-11 mm) and 3 mm (0-4 mm) from the cortex, respectively. The sensitivity and specificity of radiographs to detect IOI screws was 39% and 92%, respectively. The incidence of osteonecrosis and revision surgeries in hips, with and without IOI screws, was 6% versus 6% [Odds ratio (OR) 1.1, 95% confidence interval (CI) 0.2-5.3] and 10% versus 10% (OR 1.0, CI 0.3-3.1), respectively; a true clinical difference cannot be excluded due to the width of the confidence intervals.

CONCLUSIONS

There was a high incidence of IOI posterosuperior screws on CT scans. Postoperative radiographs had a poor sensitivity for detecting IOI screws. A larger sample size is necessary to evaluate the association of IOI screws with osteonecrosis and revision surgery.

LEVEL OF EVIDENCE

Level III, comparative cohort study.

Total Hip Arthroplasty for the Sequelae of Femoral Neck Fractures in the Pediatric Patient

Although rare, total hip arthroplasty (THA) may be indicated in pediatric patients with degenerative changes of the hip joint after previous trauma. To illustrate management principles in this patient population, this study describes the case of a 15-year-old female who sustained bilateral femoral neck fractures after a generalized tonic-clonic seizure, an atypical, low-energy mechanism for this injury. These fractures were not diagnosed until 14 weeks after the seizure episode, at which point they had progressed to nonunion on the left side, malunion on the right side, and degenerative hip joint changes were developing bilaterally. Bilateral THA was ultimately performed, and the patient had favorable outcomes at 1 year postoperatively. In determining the optimal management strategy for such patients, a multidisciplinary approach should be used, with input from the patient’s family, pediatrician, pediatric endocrinologist, pediatric orthopaedic surgeon, and adult reconstruction surgeon. From a surgical standpoint, this report highlights the importance of selecting the appropriate bearing surfaces, broaching technique, mode of implant fixation, and implant features when performing THA in the active pediatric patient.

Outcomes of Femoral Neck Fractures Treated with Cannulated Internal Fixation in Elderly Patients: A Long-Term Follow-Up Study

Objectives

To evaluate the long‐term efficacy of cannulated internal fixation in patients who sustain femoral neck fracture (FNF) and risk factors influencing the outcomes.

Methods

This retrospective study analyzed data from 73 elderly patients aged ≥60 years old, hospitalized for FNF and treated with cannulated internal fixation between August 2008 and July 2016. The inclusion criteria were: (i) patients aged ≥60 years; (ii) patients with recent femoral neck fracture, with times of injury ranging from 12–72 h; and (iii) patients who underwent Garden II–IV closed reduction and internal fixation. Patients were classified based on the Garden fracture type and Pauwels angle. Clinical data and radiographs before and after the surgery were collected. Subsequently, surgery was performed with the patient in supine position, under general or lumbar epidural anesthesia. Closed reduction was performed until satisfactory fracture reduction quality was achieved. The weight of all included patients were <75 kg, and thus, minimal internal fixation was performed. The ischemic necrosis of the femoral head was diagnosed by considering the symptoms, signs, and radiological findings. Harris hip scores were used to evaluate postoperative recovery of hip function. Furthermore, relationships between Garden fracture type and necrosis rate of the femoral head, Pauwels angle and necrosis rate of the femoral head, Garden fracture type and Harris hip score, and age and Harris hip score were analyzed.

Results

The mean duration of surgery was 1 ± 0.17 h and blood loss for all the patients was approximately 15 mL. The included patients were followed up for 13–128 months, with an average follow‐up of 61 months. Among the included 73 patients, 65 (89.0%) exhibited satisfactory union, seven (9.6%) had femoral head necrosis, and one (1.4%) had nonunion. For seven patients with femoral head necrosis, there were two, two, and three patients classified as Garden IV, Garden III, and Garden II, respectively, and two and five patients classified as Pauwels II and Pauwels III, respectively. Among the seven cases, four underwent hip replacement. Garden fracture type was not significantly associated with femoral head necrosis (χ² = 0.44, P > 0.05) or Harris score (χ² = 1.43, P > 0.05). Patients with Pauwels I (0%) and II (4.3%) fractures exhibited a significantly lower necrosis rate than those with Pauwels III fractures (41.7%) (P < 0.05).

Conclusions

Cannulated internal fixation was more suitable for older Chinese patients with Pauwels I/II fractures than those with Pauwels III fractures.

Therapeutic Applications of Genes and Gene-Engineered Mesenchymal Stem Cells for Femoral Head Necrosis

Osteonecrosis of the femoral head (ONFH) is a common and disabling joint disease. Although there is no clear consensus on the complex pathogenic mechanism of ONFH, trauma, abuse of glucocorticoids, and alcoholism are implicated in its etiology. The therapeutic strategies are still limited, and the clinical outcomes are not satisfactory. Mesenchymal stem cells (MSCs) have been shown to exert a positive impact on ONFH in preclinical experiments and clinical trials. The beneficial properties of MSCs are due, at least in part, to their ability to home to the injured tissue, secretion of paracrine signaling molecules, and multipotentiality. Nevertheless, the regenerative capacity of transplanted cells is impaired by the hostile environment of necrotic tissue in vivo, limiting their clinical efficacy. Recently, genetic engineering has been introduced as an attractive strategy to improve the regenerative properties of MSCs in the treatment of early-stage ONFH. This review summarizes the function of several genes used in the engineering of MSCs for the treatment of ONFH. Further, current challenges and future perspectives of genetic manipulation of MSCs are discussed. The notion of genetically engineered MSCs functioning as a "factory" that can produce a significant amount of multipotent and patient-specific therapeutic product is emphasized.

Platelet-Rich Plasma-Incorporated Autologous Granular Bone Grafts Improve Outcomes of Post-Traumatic Osteonecrosis of the Femoral Head

BACKGROUND

To investigate the effects of platelet-rich plasma (PRP)-incorporated autologous granular bone grafts for treatment in the precollapse stages (Association of Research Circulation Osseous stage II-III) of posttraumatic osteonecrosis of the femoral head.

METHODS

A total of 46 patients were eligible and enrolled in the study. Twenty-four patients were treated with core decompression and PRP-incorporated autologous granular bone grafting (treatment group), and 22 patients were treated with core decompression and autologous granular bone grafting (control group). During a minimum follow-up duration of 36 months, X-ray and computed tomography were used to evaluate the radiological results, and the Harris hip score (HHS) and visual analog scale were chosen to assess the clinical results.

RESULTS

Both the treatment and control groups had a significantly improved HHS (P < .001). The minimum clinically important difference for the HHS was reached in 91.7% of the treatment group and 68.2% of the control group (P < .05). The HHS and visual analog scale in the treatment group were significantly improved than that in the control group at the last follow-up (P < .05). Successful clinical and radiological results were achieved 87.5% and 79.2% in the treatment group compared with 59.1% and 50.0% in the control group (P < .05), respectively. The survival rates based on the requirement for further hip surgery as an endpoint were higher in the treatment group in comparison to those in the control group (P < .05).

CONCLUSION

PRP-incorporated autologous granular bone grafting is a safe and effective procedure for treatment in the precollapse stages (Association of Research Circulation Osseous stage II-III) of posttraumatic osteonecrosis of the femoral head.

Magnesium and vitamin C supplementation attenuates steroid-associated osteonecrosis in a rat model

Magnesium (Mg)-based biometal attracts clinical applications due to its biodegradability and beneficial biological effects on tissue regeneration, especially in orthopaedics, yet the underlying anabolic mechanisms in relevant clinical disorders are lacking. The present study investigated the effect of magnesium (Mg) and vitamin C (VC) supplementation for preventing steroid-associated osteonecrosis (SAON) in a rat experimental model. In SAON rats, 50 mg/kg Mg, or 100 mg/kg VC, or combination, or water control was orally supplemented daily for 2 or 6 weeks respectively. Osteonecrosis was evaluated by histology. Serum Mg, VC, and bone turnover markers were measured. Microfil-perfused samples prepared for angiography and trabecular architecture were evaluated by micro-CT. Primary bone marrow cells were isolated from each group to evaluate their potentials in osteoblastogenesis and osteoclastogenesis. The mechanisms were tested in vitro. Histological evaluation showed SAON lesions in steroid treated groups. Mg and VC supplementation synergistically reduced the apoptosis of osteocytes and osteoclast number, and increased osteoblast surface. VC supplementation significantly increased the bone formation marker PINP, and the combination significantly decreased the bone resorption marker CTX. TNFα expression and oxidative injury were decreased in bone marrow in Mg/VC/combination group. Mg significantly increased the blood perfusion in proximal tibia and decreased the leakage particles in distal tibia 2 weeks after SAON induction. VC significantly elevated the osteoblast differentiation potential of marrow cells and improved the trabecular architecture. The combination supplementation significantly inhibited osteoclast differentiation potential of marrow cells. In vitro study showed promoting osteoblast differentiation effect of VC, and anti-inflammation and promoting angiogenesis effect of Mg with underlying mechanisms. Mg and VC supplementation could synergistically alleviate SAON in rats, indicating great translational potentials of metallic minerals for preventing SAON.

Correlation Between Reduction Quality of Femoral Neck Fracture and Femoral Head Necrosis Based on Biomechanics

Objective

To investigate the biomechanical effects of reduction quality on patients after femoral neck fracture internal fixation.

Methods

The data of individual patients with femoral neck fractures were reviewed. Data for patients with simple unilateral femoral neck fractures whose reduction quality was evaluated as good by hip X‐ray films after internal fixation were collected from January 2013 to January 2017. The CT data of the patients was used to reconstruct 3D models of the femur and the screw. The spatial displacement after the operation of femoral neck fracture was measured, which included the displacement of the deepest portion of the femoral head fovea, the displacement of the center of the femoral head, and the rotational angle. The cases were followed up by telephone consultation and clinical review to determine whether the osteonecrosis of the femoral head occurred. Follow‐up time should be more than 18 months after surgery. The cases were grouped according to the results into an osteonecrosis of the femoral head group and a non‐osteonecrosis of the femoral head group. Finally, the differences in postoperative spatial displacement between the two groups were compared and analyzed. In addition, a mechanical analysis of femoral force during gait was performed via finite element analysis.

Results

Data for 241 patients with femoral neck fractures who were treated with closed reduction and internal fixation were collected. 3D measurement showed the average displacement value, including the center of the femoral head (5.90 ± 3.4 mm), the deepest portion of the femoral head fovea (9.32 ± 4.8 mm), and the rotational angle (16.1° ± 9.4°). After telephone consultation and clinical review, osteonecrosis of the femoral head was diagnosed in 28 (11.62%) of the patients. In the osteonecrosis of the femoral head (ONFH) group, the displacement of the deepest portion of the femoral head fovea was 10.92 ± 9.18 mm; the displacement was 8.86 ± 6.29 mm in the non‐ONFH group. The displacement of the center of the femoral head in the ONFH group was 7.575 ± 5.69 mm and 5.31 ± 4.05 mm in non‐ONFH group. The rotational angle was 20.11° ± 10.27° in the ONFH group and 14.19° ± 11.09° in the non‐ONFH group. The statistical analysis showed that the postoperative spatial displacements, including the displacement of the deepest portion of the femoral head fovea, the displacement of the center of the femoral head, and the rotational angle between the two groups, had statistical differences. Finite element analysis showed that as the spatial displacement increased, the stress, the displacement, and the equivalent strain of the proximal femur also increased.

Conclusion

Poor reduction quality after femoral neck fracture is a risk factor for re‐fracture and femoral head necrosis, and the measurement method of this study can be used to predict the occurrence of femoral head necrosis early after femoral neck fracture.

[Pathophysiology of aseptic femoral head necrosis: Pathogenesis and histopathological differential diagnosis]

BACKGROUND

Aseptic osteonecrosis is characterized by a complete death of the tissue (necrosis), more specifically, an ischemic necrosis of the lamellar bone tissue. The denotation aseptic refers to causal pathogenesis; therefore, it is not a matter of an infectious, septic-induced bone necrosis as in the case of acute infectious osteomyelitis. Formal pathogenesis leads to either (1) a hypoperfusion of the lamellar bone in the sense of an ischemic necrosis or (2) to directly induced damage of osteocytes and osteoblasts, which causes aseptic osteonecrosis.

CAUSE

The causes of hypoperfusion/ischemia are manifold and entail vascular malformations, coagulopathies, haemoglobinopathies, thrombotic embolisms, myeloproliferative illnesses, air embolisms, decompression-caused illnesses, macro as well as micro traumata and, finally, vasculitis with necrosis, which complete the vascular-induced spectrum. Direct toxic damage to the osteocytes and osteoblasts is primarily caused by alcohol abuse, medical drug therapies (i. e. chemotherapeutic substances or cortisone) and disorders of the lipid embolism. Contemporary molecular and cellular models of pathogenesis assume a so-called dysbalance of the catabolic and anabolic osseous metabolism in osteocytes and osteoblasts. The RANKL-RANK system, the ROS system and PPAR-gamma signal transduction are involved in the molecular pathogenesis.

DIFFERENTIAL DIAGNOSIS

The most relevant histopathologic differential diagnosis entails the complete spectrum of focal osseous changes among which osteonecrosis can occur to a diverse extent: infectious osteomyelitis, chronic immunologic induced osteomyelitis, pseudoarthrosis, infected pseudoarthrosis, bone fractures and malignant metastatic intraosseous diseases and non-metastatic intraosseous malignant diseases.

The relationship between femoral neck fracture in adult and avascular necrosis and nonunion: A retrospective study

Background

One of the most serious sequelae of femoral neck fractures (FNFs) is avascular necrosis (AVN), and this complication translates to significant morbidity and mortality. This study was conducted to determine the relationship between the etiologies and management of FNFs at our institution and the development of AVN or nonunion.

Materials and methods

This study was a retrospective medical chart review of all adult patients admitted and managed for FNF.

Results

There were a total of 69 FNF patients reviewed. FNF was caused by a fall in 37 patients (53.6%), a road traffic accident in 16 (23.2%), motorcycle and motorbike accidents in 8 (11.6%), and heavy exercise in 8 (11.6%). Twenty-four patients (34.8%) had fixation within 24 h of injury, and 45 (65.2%) went more than 24 h before fixation. The mean RUSH score at 6 months was 21.4 ± 5.1. There were 4 patients (5.8%) with a collapsed FNF and 4 patients (5.8%) had a nonunion FNF. AVN was documented in 12 patients (17.4%). Of the 12 patients who had AVN, 8 (66.7%) received fixation within 24 h from the time of the injury, whereas only 4 (33.3%) received fixation more than 24 h after the injury. There was a significant negative correlation between the time of fixation and AVN.

Conclusion

We report a 17.4% incidence of AVN over 10 years in patients managed with FNF. AVN was found to be significantly correlated with the mode of injury (fall and RTA among younger male patients).

•

Avascular necrosis is a serious sequelae of femoral neck fracture.

•

It has been noted that time is essential in the management of FNFs.

•

We found that there is no association between late fixation of the FNF and the development of AVN.

The effect of patient, fracture and surgery on outcomes of high energy neck of femur fractures in patients aged 15-50

INTRODUCTION:

High-energy femoral neck fractures in young patients can be devastating, with the risk of osteonecrosis, nonunion, malunion and lifelong morbidity. The aim of this study is to define the effects of patient, fracture and surgical factors on the outcome of high-energy femoral neck fractures in patients aged from 15 to 50 years.

METHODS:

A retrospective review was conducted of high-energy femoral neck fractures in patients aged 15-50 managed surgically at a Level 1 Trauma Centre, using a prospectively recorded trauma database. Low energy trauma (including falls from <1 m), medical conditions adversely affecting bone density, and pathological fractures were excluded. A clinical and radiological review was performed. The primary outcome measures were the development of osteonecrosis or nonunion leading to total hip arthroplasty (THA). Secondary outcome measures included osteotomy or other surgical procedures, quality of reduction and malunion.

RESULTS:

32 patients meeting the inclusion criteria were identified between January 2008 and July 2015. The mean follow-up was 58.5 months (range 980-3,048 days). 3 patients (9.4%) required THA. No other surgical procedures were performed. None of the 29 other patients developed radiologically apparent osteonecrosis. Fracture type, displacement, anatomical reduction and fixation type were not statistically significant risk factors affecting these outcomes. For all patients, an average of 8% loss of femoral neck height and 10% femoral neck offset were seen.

CONCLUSIONS:

At a mean 4.9-year follow-up, the incidence of high-energy femoral neck fractures leading to THA was 9.4%, as a consequence of osteonecrosis or nonunion. Malunion was common.

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.

Femur neck fracture in young adults, is it really an urgent surgery indication: retrospective clinical study

Introduction

Femur neck fracture comprises a significant part of intracapsular femur fracture in the intracapsular area of proximal femur and it is mostly seen in elder people. However, these kinds of fractures may be seen in young adults. The present study aims to search factors that affect femoral neck fractures in young adults after surgery carried out by internal determination method.

Methods

Files of patients who were applied internal determination through closed reduction and cannulated screw because of intracapsular femur neck fractures between 2010 and 2015 were analyzed retrospectively. Fractures were evaluated by means of Garden classification, which is based on radiological appearance. The cases were examined in terms of timing of surgery in two groups. Cases operated in the first 24 hours after trauma consisted of group 1 and after 24 hours group 2. Radiological staging in femoral head avascular necrosis was evaluated by Ficat-Arlet classification system whereas acetabular fractures and hip functionality was evaluated by Letournel and Judet system, which is based on direct graph of fracture line.

Results

Mean age at the time of surgery for 31 cases included in the study was 40.04 ± 9.63 year. The average duration from injury to surgery was 6.6 (1-20) days. Thirty nine percent of fractures was nondisplaced whereas 61% was displaced. The average follow-up period was 4.9 ± 1.35 years. The rate of nonunion was found 16% and femoral head avascular necrosis 6.4%. According to Judet System, 67.7% of cases showed excellent/good and 32.3% moderate/bad functional results. Six cases had a secondary surgery. Cases who had displaced fractures statistically showed worse functional results and underwent more secondary surgery than patients with nondisplaced fractures (P>0.05). As a result of logistic regression analysis, presence of displacement was a factor negatively affecting the judet score but did not affect the rate of complication. There were no significant differences between the two groups according to the surgical timing in terms of functional outcomes and complications.

Conclusion

Because of surgical treatment of femoral neck fractures in the first 24 hours does not affect functional outcomes and complication rate, surgery is recommended in optimal conditions. In the case of displacement, care must be taken in terms of poor functional results.

Threading the Needle: Intrapelvic Displacement of a Femoral Neck Fracture through the Obturator Foramen

Despite timely and appropriate management, displaced femoral neck fractures are often devastating injuries for the young patient. The risk of negative sequelae is further amplified with increasing displacement and vertical fracture patterns. Open anatomic reduction with rigid internal fixation is essential to maximize the healing potential in displaced fractures of the femoral neck. Successful primary osteosynthesis of significantly displaced femoral neck fractures in the young patient has been reported in the literature. We present a unique case of open reduction and internal fixation of a high-energy femoral neck fracture with extrusion of the head through the obturator foramen into the pelvis without associated acetabular or pelvic injury.

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 AND 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.

A systematic review of undisplaced femoral neck fracture treatments for patients over 65 years of age, with a focus on union rates and avascular necrosis

BACKGROUND

It remains unclear whether conservative treatment should be used to treat the common undisplaced femoral neck fractures that develop in the elderly. Herein, we systematically review the rates of union and avascular necrosis after conservative and surgical treatment of undisplaced femoral neck fractures.

METHODS

We searched the EMBASE, PubMed, OVID, Cochrane Library, Web of Science, and Scopus databases for randomized controlled trials or observational studies that assessed the outcomes of conservative or surgical treatments of undisplaced femoral neck fractures. No language or publication year limitation was imposed. Statistical analyses were performed with the aid of the chi-squared test. We evaluated the quality of each publication and the risk of bias.

RESULTS

Twenty-nine studies involving 5071 patients were ultimately included; 1120 patients were treated conservatively and 3951 surgically. The union rates were 68.8% (642/933) and 92.6% (635/686) in the former and latter groups, respectively (p < 0.001). The avascular necrosis rate in the conservatively treated group was 10.3% (39/380), while it was 7.7% (159/2074) in the surgically treated group (p = 0.09).

CONCLUSIONS

Surgery to treat undisplaced femoral neck fractures was associated with a higher union rate and a tendency toward less avascular necrosis than conservative treatment.

Dimethyloxaloylglycine increases bone repair capacity of adipose-derived stem cells in the treatment of osteonecrosis of the femoral head

Mesenchymal stem cells have been widely studied to promote local bone regeneration of osteonecrosis of the femoral head (ONFH). Previous studies observed that dimethyloxaloylglycine (DMOG) enhanced the angiogenic and osteogenic activity of mesenchymal stem cells by activating the expression of hypoxia inducible factor-1α (HIF-1α), thereby improving the bone repair capacity of mesenchymal stem cells. In the present study, it was investigated whether DMOG could increase the bone repair capacity of adipose-derived stem cells (ASCs) in the treatment of ONFH. Western blot analysis was performed to detect HIF-1α protein expression in ASCs treated with different concentrations of DMOG. The results showed DMOG enhanced HIF-1α expression in ASCs in a dose-dependent manner at least for 7 days. Furthermore, DMOG-treated ASCs were transplanted into the necrotic area of a rabbit model of ONFH to treat the disease. Four weeks later, micro-computed tomography (CT) quantitative analysis showed that 58.8±7.4% of the necrotic area was regenerated in the DMOG-treated ASCs transplantation group, 45.5±3.4% in normal ASCs transplantation group, 25.2±2.8% in only core decompression group and 10.6±2.6% in the untreated group. Histological analysis showed that transplantation of DMOG-treated ASCs clearly improved the bone regeneration of the necrotic area compared with the other three groups. Micro-CT and immunohistochemical analysis demonstrated the revasculation of the necrotic area were also increased significantly in the DMOG-treated ASC group compared with the control groups. Thus, it is hypothesized that DMOG could increase the bone repair capacity of ASCs through enhancing HIF-1α expression in the treatment of ONFH.

Is Disuse Osteopenia a Favorable Prognostic Sign After Femoral Neck Fracture?

OBJECTIVES

Avascular necrosis (AVN) of the femoral head is a devastating complication following fixation of femoral neck fractures in younger adults. In this study, we investigate the prognostic utility of disuse osteopenia.

DESIGN

Retrospective study.

SETTING

Three academic Level 1 trauma centers.

PATIENTS

One hundred twenty patients younger than 60 years treated for a femoral neck fracture.

INTERVENTION

N/A.

MAIN OUTCOME MEASURES

The presence of sclerosis or osteopenia, compared to the contralateral femoral head, was measured 6 weeks from injury both subjectively and using a novel radiographic measure, the relative density ratio (RDR). The outcome measure was radiographic development of AVN.

RESULTS

The presence of relative sclerosis was associated with AVN and overall treatment failure. Patients with subjective relative sclerosis had a 12.6 (95% confidence interval, 2.9-61.3; P < 0.001) times higher odds of developing AVN. Multiple logistic regression showed that for every 0.10 increase in the RDR, there was a 5.2 increase in the odds (95% confidence interval, 2.1-26.9; P = 0.009) of developing AVN. Patients with an RDR of ≥1.2 have an 80% probability of AVN, whereas those with an RDR ≤0.8 have a <1% probability of developing AVN.

CONCLUSIONS

Disuse osteopenia detected on 6-week radiographs is a favorable prognostic sign following fixation of femoral neck fractures. Patients who have relative sclerosis of the femoral head at 6-week follow-up are at a higher risk of developing AVN.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

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.

Guideline for Diagnostic and Treatment of Osteonecrosis of the Femoral Head

There is a new knowledge for clinical presentations and findings of imagine in patients with osteonecrosis of the femoral head (ONFH) in recent more than ten years. According to clinical data in Chinese huge patients with ONFH, the guideline for diagnosis and treatment of ONFH has been put forward by Chinese specialists. The newer contents of guideline include the definition for predisposing risk factors of ONFH, the new knowledge for clinical manifestations, the new interpretation for changes of imagine, important differential diagnosis. Based on the supplementary and revision for widely used staging and classification system, the new Chinese staging and classification system have been established. The advantages of Chinese staging and classification system accord with clinical and pathological features, it could be predicted the prognosis, and clinical applications are convenient. The guideline gives a brief account of principles for treatment selection and treatment methods for enhancement of diagnosis and treatment for ONFH.

Outcome of transtrochanteric rotational osteotomy for posttraumatic osteonecrosis of the femoral head with a mean follow-up of 12.3 years

INTRODUCTION

This study examined the outcomes of applying transtrochanteric rotational osteotomy (TRO) for posttraumatic osteonecrosis of the femoral head (ON).

PATIENTS AND METHODS

We retrospectively reviewed 28 hips in 28 patients (male, n = 17; female n = 11) with a mean age of 34.8 years (12-61 years) at the time of TRO. Transtrochanteric anterior rotational osteotomy (ARO) was used when the lesion was localized on the anterior aspect of the femoral head, and transtrochanteric posterior rotational osteotomy (PRO) was indicated in patients with lesions limited to the posterior aspect of the femoral head. The mean follow-up period was 12.3 years (5.0-21.3 years). We investigated the patients' clinical and radiological factors, including age, sex, body mass index, preoperative Harris Hip Score (HHS), type of antecedent trauma, preoperative stage, and postoperative intact ratio (the ratio of the intact articular surface of the femoral head to the weight-bearing surface of the acetabulum). We divided the patients into a hip-survival group and a conversion-to-total hip arthroplasty (THA) group and then compared these factors between the two groups.

RESULTS

At the final follow-up, 22 hips had survived with a mean HHS of 85.8. The remaining six hips underwent THA at a mean of 10.2 years after TRO. The preoperative stage was correlated with hip survival. Furthermore, the postoperative intact ratio was significantly lower in the conversion-to-THA group. Based on the receiver operating characteristic curve, a ratio of less than 33.6 % was found to be associated with the need to convert to THA.

CONCLUSIONS

TRO to correct posttraumatic ON resulted in favorable midterm results. The possible risk factors for conversion to THA were an advanced preoperative stage and a postoperative intact ratio of less than 33.6 %.

Predictive value of single photon emission computerized tomography and computerized tomography in osteonecrosis after femoral neck fracture: a prospective study

PURPOSE

Osteonecrosis of the femoral head (ONFH) is a very common complication after femoral neck fracture. The purpose of this study was to assess the femoral head vascularity after femoral neck fracture using single photon emission computerized tomography and computerized tomography (SPECT/CT), and to evaluate its value in predicting ONFH.

METHODS

Between January 2008 and March 2011, 120 patients diagnosed with femoral neck fracture underwent SPECT-CT before the internal fixation. The fracture was classified according to the Garden classification. The ratios of the radionuclide uptake of the fractured femoral head to that of the contralateral femoral head (F/N) were calculated to assess the femoral head vascularity. After a minimum of two years' follow-up, magnetic resonance imaging (MRI) was used as the "gold standard" for the diagnosis of possible ONFH.

RESULTS

A total of 114 patients completed the study. The SPECT/CT examination showed that the F/N ratios of Garden I, II, III and IV were 2.6, 1.8, 0.8, and 0.6, respectively. At the time of the most recent follow-up, osteonecrosis developed in two of the 27 patients who had a Garden Stage-II fracture, in eight of the 34 patients who had a Garden Stage-III fracture, and nine of the 27 patients who had a Garden Stage-VI fracture. With a cutoff of 0.55 from the receiver operating characteristic (ROC) curve, F/N ratio showed a sensitivity of 97%, a specificity of 79%, a positive predictive value of 95%, and a negative predictive value of 19%.

CONCLUSION

SPECT-CT proved to be reliable and valid for predicting ONFH after femoral neck fracture.