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

Positive buttress reduction in femoral neck fractures: a literature review

BACKGROUND

Femoral neck fractures (FNFs) in young adults are usually caused by high-energy trauma, and their treatment remains a challenging issue for orthopedic surgeons. The quality of reduction is considered an important factor in improving the poor prognosis of patients with FNFs. In recent years, positive buttress closed reduction technique has received widespread attention in the treatment of FNFs. This comprehensive literature review is designed to encapsulate the impacts of both non-anatomic and anatomic reduction on the biomechanical stability, clinical outcomes, and postoperative complications in the management of FNFs, conjecture the efficacy of positively braced reduction techniques and provide a thorough summarization of the clinical outcomes.

METHODS

In this literature review, we have examined all clinical and biomechanical studies related to the treatment of FNFs using non-anatomical reduction or positive and negative buttress reduction. PubMed, Web of Science, Google Scholar and Embase Library databases were searched systematically for studies published before September 1, 2023. Published literature on fracture reduction techniques for treating FNFs was reviewed. In addition, we evaluated the included literature using the MINORs tool.

RESULTS

Although the "arch bridge" structure formed by the positive buttress reduction technique improved the support to the cortical bone and provided a more stable biomechanical structure, no significant differences were noted in the clinical efficacy and incidence of postoperative complications between the positive buttress reduction and anatomical reduction.

CONCLUSION

Positive buttress reduction is an effective treatment method for young patients with FNFs. When facing difficult-to-reduce FNF, positive buttress reduction should be considered first, followed by anatomical reduction. However, negative buttress reduction should be avoided.

High-energy Femoral Neck Fractures in Young Patients

Femoral neck fractures in physiologically young patients typically occur from high-energy axial loading forces through the thigh with the hip in an abducted position. These fractures have a high rate of associated head, chest, abdominal, and musculoskeletal injuries. High-energy hip fractures differ from traditional geriatric hip fractures regarding incidence, mechanism, management algorithms, and complications. After adequate resuscitation, goals of treatment include anatomic reduction and stable fixation while maintaining vascularity of the femoral head, which can be achieved through a variety of different techniques. Prompt recognition and treatment of these fractures is crucial to achieve a successful outcome because these injuries are often associated with complications such as osteonecrosis, fixation failure, and nonunion.

Association of hardware removal with secondary osteonecrosis following femoral neck fractures: a systematic review and meta-analysis

BACKGROUND

It has been controversial that whether hardware removal will increase the risk of osteonecrosis of femoral head (ONFH) in fracture-healed patients who underwent internal fixation for femoral neck fractures (FNFs). This meta-analysis aimed to clarify the association of hardware removal with secondary hardware removal-induced ONFH (HR-ONFH).

METHODS

Four electronic databases (PubMed, Embase, Web of Science, Cochrane Library) were searched for eligible studies published up to March 10, 2023. Studies reporting the relative risk of hardware status (i.e., risk rate, odds ratio [OR], or hazard ratio [HR]) were included. Newcastle-Ottawa scale (NOS) was used to assess risk of bias of included observational studies. Review Manager software was used to pool ORs and adjusted ORs.

RESULTS

Five studies were included into quantitative synthesis. Hardware removal was associated with a reduced risk of HR-ONFH in the synthesis of crude odds ratios (OR, 0.62, 95% CI 0.39-0.96). In the synthesis of adjusted odds ratios, hardware removal was associated with an increased risk of HR-ONFH (OR, 1.76, 95% CI 1.23-2.51).

CONCLUSION

This study demonstrates that hardware removal was associated with an increased incidence of HR-ONFH in fracture-healed patients who underwent internal fixation due to FNFs.

Comparison of percutaneous compression plate to parallel screws in the treatment of nondisplaced femoral neck fractures in elderly patients: a prospective, randomized study

BACKGROUND

The optimal internal fixation for non-displaced femoral neck fractures remains controversial. This study aimed to compare the clinical results of the percutaneous compression plate (PCCP) with parallel screws (PS) in treating femoral neck fractures in elderly patients.

MATERIALS AND METHODS

A total of 218 patients who underwent internal fixation were randomized to receive either a percutaneous compression plate (PCCP group) or parallel screws (PS group) using a computerized random sequence generator which was used to assign the order of randomization. Patients were assessed by the operating time, intraoperative blood loss, hemoglobin level drop, postoperative hospital stay, the time to full weight-bearing, reduction quality, fracture healing time, Harris hip score, and postoperative complications.

RESULTS

There was no significant difference between PCCP and PS groups regarding operative time, intraoperative blood loss, hemoglobin level drop, postoperative hospital stays, reduction quality, and Harris hip score (p > 0.05). The time to full weight-bearing and the fracture healing time in the PCCP group were shorter than those in the PS group (p < 0.05). The overall complication rates were slightly lower in the PCCP compared to the PS patients, but there was no significant difference (p > 0.05). However, the implant failure rate was significantly higher in the PS group compared to the PCCP group (p < 0.05).

CONCLUSIONS

The present study suggests that the PCCP is superior to the parallel screws fixation in the treatment of non-displaced elderly femoral neck fractures in terms of earlier full weight-bearing, shorter fracture healing time, and lower implant failure rate. Therefore, it may be a better therapeutic strategy for non-displaced femoral neck fractures in elderly patients.

Surgical management of neck of femur fractures in patients younger than sixty-five years: a comparative study of three fixation methods

PURPOSE

Several surgical implants have been used for the treatment of neck of femur fracture (NOF) in younger patients such as dynamic hip screw (DHS) and cannulated compression screw. However, the superiority of one or another osteosynthesis device remains a matter of debate. The aim of this work is to evaluate and compare three fixation modalities: Cannulated Hip Screws (CHS), DHS and DHS associated to anti-rotating screw for surgical treatment of femoral neck fracture in young adults.

METHODS

It is a retrospective comparative study of three series of NOF fractures treated surgically over a period of ten years; including young adult patients (age > 18 years and < 65 years) treated conservatively using closed or open reduction and internal fixation. All types of NOF fractures according to Garden classification were included. Pathological, basi-cervical fractures and fractures on previously operated hips were excluded. The minimum follow-up recommended was two years. Clinical evaluation was based on the Postel Merle d'Aubigné score (PMA), the visual analogue scale (VAS), the Parker score, and the Hip Disability and Osteoarthritis Outcome Score (HOOS score). Reduction quality was assessed on X-rays.

RESULTS

Our series included 72 patients that were divided in three groups: Group A: Fixation using cannulated hip screws (33 patients). Group B: Fixation using DHS only (21 patients). Group C: Fixation using DHS associated to anti-rotation screw (18 patients). The patients of group A had better PMA and VAS scores, but there was no statistically significant difference. However, a significant difference (p=0.001) was found for the HOOS score. The fractures treated with DHS associated with anti-rotating screws, had the highest loss of reduction in the vertical axis (Yp) with the highest femoral head collapse (Zp) values. Group A had the lowest loss of reduction in the horizontal axis (Xp). There was no significant difference between the three methods of osteosynthesis in terms of loss of correction though.

CONCLUSION

We found comparable results in terms of healing and complication rates and loss of reduction for the three groups with no significant difference. However, the HOOS score was significantly better in the cannulated hip screw group.

Factors associated with early failure of the femoral neck system (FNS) in patients with femoral neck fractures

BACKGROUND

Femoral neck system (FNS) is a new type of internal fixation system which has been widely used for treating femoral neck fractures (FNFs).Compared with other internal fixation methods, FNS is minimally invasive and stable, and often achieves satisfactory short-term efficacy.Early failure of FNS (EFFNS) is not uncommon, however, there are few literatures and reports on factors associated with EFFNS.This study aimed to survey the prevalence and risk factors of EFFNS.

METHODS

We retrospectively analysed 62 patients with FNFs and underwent FNS fixation between 2019 and 2021. Demographic data, clinical characteristics, radiographic features and treatment process were described. Multifactor logistic regression analysis was used to analyse the different influencing factors.

RESULTS

Out of the 62 FNFs patients, 10 patients (16.1%) developed EFFNS, including 6 cases of severe femoral neck shortening, 2 cases of screw-out, 1 case of avascular necrosis of the femoral head and 1 case of nonunion. In the failure group, all patients were younger than 65 years old, which was significantly higher than 59.6% in the healing group (P = 0.012). There were no significant differences in sex(P = 0.490), BMI (P = 0.709), injured side (P = 0.312), injury mechanism (P = 0.617), reduction method(P = 0.570),femoral neck-shaft angle(P = 0.545), Pauwels classification (P = 0.564) and Garden classification (P = 0.195). Moreover, we not found that Garden classification (P = 0.464) and age (P = 0.128) were statistically significant risk factors for EFFNS at multivariate analysis.

CONCLUSION

In this study, sex, BMI, injury side, injury mechanism, reduction method, Pauwels angle, femoral neck-shift angle, Pauwels classification and Garden classification were excluded as EFFNS risk factors. Moreover, our study demonstrated that age and Garden classification were not significant risk factors at multivariate analysis.

TRIAL REGISTRATION

ChiCTR, ChiCTR2100051360. Registered on 21 September, 2021. https://www.chictr.org.cn/index.aspx .

The association between three-dimensional measurement of posterior tilt angle in impacted femoral neck fractures and osteonecrosis of the femoral head

BACKGROUND

Hollow screw internal fixation is commonly used in clinical treatment of impacted femoral neck fractures. Previous studies have demonstrated a correlation between the preoperative posterior tilt angle of the femoral head and failure of internal fixation, but there are fewer studies related to the occurrence of postoperative femoral head necrosis and the posterior tilt angle.

METHODS

To examine the relationship between three-dimensional posterior tilt angle measurements in affected femoral neck fractures and postoperative osteonecrosis of the femoral head and related risk variables. We retrospectively examined 130 Yantaishan Hospital patients with affected femoral neck fractures from 2019 to 2022. Three-dimensional reconstruction technology assessed the posterior tilt angle of the femoral head and separated patients into necrosis and non-necrosis groups based on postoperative femoral head necrosis. Univariate analysis compared clinical data between groups, and multivariate logistic regression analyzed risk variables for femoral head necrosis. Postoperative femoral head necrosis was predicted by posterior tilt angle using Receiver operating characteristic (ROC) curve analysis.

RESULTS

Out of 130 patients who were followed up for 16-68 months postoperatively, 20 developed femoral head necrosis. Multivariate logistic regression analysis indicated that the posterior tilt angle and reduction quality level C were risk factors for the occurrence of femoral head necrosis. The ROC curve analysis showed that the three-dimensional measurement of the posterior tilt angle had predictive value for postoperative femoral head necrosis, with a cut-off value of 20.6°.

CONCLUSIONS

These results suggest that, for patients with impacted femoral neck fractures, the posterior tilt angle and reduction quality level C are risk factors for femoral head necrosis following closed reduction and internal fixation surgery. Fracture patients with a posterior tilt angle ≥ 20.6°are more likely to experience postoperative femoral head necrosis.

Analysis of Factors Influencing Postoperative Femoral Head Collapse in Patients With Ficat I, II, and III Stages of Aseptic Necrosis of the Femoral Head

OBJECTIVE

To investigate the factors influencing postoperative femoral head collapse (FHC) in patients with Ficat I, II, and III stages of aseptic necrosis of the femoral head (ANFH).

METHODS

Retrospective analysis of 178 patients with ANFH admitted to our hospital from October 2018 to October 2021 was studied, and patients were categorized into the FHC group and no FHC group according to whether FHC occurred after surgery. The influencing factors causing postoperative FHC were analyzed by univariate and multifactor logistic regression.

RESULTS

In the collapsed group, there were statistically significant differences in etiology, extent of necrosis, mechanism of injury, preoperative waiting time, Japanese Femoral Necrosis Research Society staging, distance from the tip of the tantalum rod to the center of necrosis, and Harris score after treatment ( P < 0.05). The etiology, extent of necrosis, mechanism of injury, preoperative waiting time, Japanese Femoral Osteonecrosis Research Society classification, distance between the tantalum rod tip and the center of necrosis, and Harris score after treatment were set as independent variables, and postoperative FHC in patients with Ficat I, II, and III stages of ANFH was used as the dependent variable in the univariate logistic regression analysis.

DISCUSSION

Hormonal osteonecrosis of the femur, extent of necrosis, type C1 and type C2 in the Japanese Society for the Study of Femoral Osteonecrosis staging, and distance of the tip of the tantalum rod from the center of necrosis are risk factors for postoperative FHC in patients with Ficat I, II, and III stages of ANFH.

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 Risk of Avascular Necrosis Following the Stabilization of Femoral Neck Fractures: A Systematic Review and Meta-Analysis

Background: Avascular necrosis (AVN) of the femoral head often requires surgical treatment and is often associated with femoral neck fractures. We conducted a systematic review and meta-analysis of recent research on the risk of AVN following the stabilization of fractured femoral neck with implants in PubMed. We assessed the effect of age on AVN incidence among patients aged > 50 and younger, depending on fracture type, Garden stage, Pouwels degree, Delbet stage, and age category. We followed PRISMA guidelines. Relevant studies were defined as research articles describing real-world studies reporting on the risk of AVN following primary surgical fracture stabilization with implants, published between 1 January 2011 and 22 April 2021. Fifty-two papers met the inclusion criteria, with a total of N = 5930 with surgically managed fractures. The pooled mean AVN incidence was significantly higher among patients with displaced fractures (20.7%; 95% CI: 12.8−28.5%) vs. those with undisplaced fractures (4.7%; 95% CI: 3.4−6.0%). No significant correlation was observed between AVN incidence weighted by sample size and time interval from injury to surgery (p = 0.843, R2 = 0.01). In conclusion, the risk of AVN following femoral neck fractures was generally high, especially in patients with displaced fractures. The time from injury to surgery did not correlate with AVN incidence.

Investigation of the process intergrowth of bone tissue into the hole in titanium implants (Experimental research)

INTRODUCTION

Despite the use of modern implants, complications such as nonunion and avascular necrosis of the femoral head are observed in femoral neck fractures (FNF). We have created a new perforated I-beam implant for FNF osteosynthesis and developed a new osteosynthesis philosophy based not only on the mechanical and biomechanical interaction of the bone-implant system, but also on the interaction of the biological properties of the bone and the implant. The purpose of the work is to study the interaction of the biological process of the bone - its regeneration (germination) of bone tissue into the holes of the implant.

MATERIALS AND METHODS

The experiment was carried out on fourteen Chinchilla rabbits in accordance with all international standards. A perforated implant specially made of titanium (ChM, Poland) was surgically implanted into the proximal femur. The implant measurements were as follows: length - 6 mm, width - 3 mm, thickness - 2 mm, 2 holes with a diameter of 2 mm. The 14 rabbits were divided into 7 groups. After 1, 2, 3, 4, 5, 10 and 12 weeks the animals were withdrawn from the experiment according to the standard rules in sequential order. The preparations were placed in a formalin solution and sent to the pathomorphology laboratory (CITO, Russia) for histological studies.

RESULTS

Weekly histopathological studies revealed a gradual transition from the organization of a hematoma to the formation of mature bone tissue in the holes of the implants. The titanium implant is bioinert and did not cause any visible reactions from the bone tissue. Simultaneous integration of vascular proliferation and newly formed bone tissue into the implant holes were revealed. On 10-12-week preparations, the formation of trabecular structures of mature bone tissue was revealed in the holes of the implants and elements of adipose and bone marrow tissue were observed. Macroscopic examination of 4-5-week preparations showed almost complete filling of the holes with bone tissue. On 10-12-week preparations, the bone tissue in the holes of the implants did not differ from the bone tissue surrounding the implant. The processes of formation of mature bone tissue in the holes of the implants were similar to the processes of physiological bone healing (regeneration) at the fracture site.

CONCLUSIONS

The obtained results show the following: 1.The titanium implant is bioinert and does not cause any visible reactions from the bone tissue; 2. There is a gradual process of formation of new vessels, and then the formation of new bone tissue in the holes of the implant instead of the one damaged during implantation. Thus, the results of this experiment indirectly confirm our assumption that a perforated implant for FNF osteosynthesis will participate not only in the mechanical and biomechanical interaction of the bone-implant system, but will also include the 3rd element in this system - the biological properties of the bone itself. We assume that these properties of the new implant will increase blood flow in the femoral neck and partially replenish the volume of bone tissue destroyed during osteosynthesis which does not occur with FNF osteosynthesis by any of the known implants.

Avascular Necrosis of Femoral Head-Overview and Current State of the Art

Avascular necrosis (AVN) of the femoral head is caused by disruption of the blood supply to the proximal femur. The alterations in the blood supply may occur following a traumatic event or result from a non-traumatic cause. Femoral neck fracture and hip dislocation and associated surgical procedures, corticosteroid therapy, and alcohol abuse frequently lead to AVN development. Type of fracture (displaced or undisplaced) and time between injury and surgery are the most critical factors in assessing the risk of developing AVN. Diagnosis of AVN can be established based on patients’ complaints, medical history, and radiographic findings. There is no consensus on the treatment of patients with AVN to date. Non-surgical methods are dedicated to patients in the early pre-collapse stages of the disease and consist of pharmacotherapy and physiotherapy. Surgery is recommended for patients with advanced disease.

Finite element analysis of new headless compression supporting screw for the treatment of unstable femoral neck fracture

BACKGROUND

Femoral neck fracture is an unsolved challenge in orthopedics. The complication rate in particular is high. There remains a lack of consensus on the optimal choice of internal fixation for unstable femoral neck fracture.

OBJECTIVE

The study aimed to develop a new headless compression supporting screw (HCSS) for the treatment of unstable foemoral neck fracture.

METHODS

We designed a new HCSS and used a femoral neck fracture (Pauwels III fracture) model (left, fourth-generation composite, Sawbones) and three-dimensional finite element analysis to compare the biomechanical performance of HCSSs with that of cannulated compression screws (CCSs) for treatment of unstable femoral neck fracture.

RESULTS

Maximum displacement, peak von Mises stress, peak strain, and rotation for the HCSS were smaller than those for the CCS. The stress was more widely distributed for the HCSS, whereas the stress was concentrated for the CCS.

CONCLUSIONS

The HCSS resulted in better biomechanical stability than that from the CCS. For Pauwels III fractures the HCSS exhibits better resistance to shear forces and better support, providing a new clinical treatment.

Treatment of Pauwels type III femoral neck fracture with medial femoral neck support screw: a biomechanical and clinical study

A femoral neck fracture is currently one of the most common types of fracture in clinical practice. The incidence continues to increase due to traffic accidents, trauma, and osteoporosis. This research includes a biomechanical study and a clinical retrospective study. In the biomechanical studies, three groups' effects (Control Group: 3CCS, DHS group, and study Group: 3CCS + mFNSS group) were compared by vertical compression tests, torsion tests, and fatigue tests. All the data were collected and analyzed. We subsequently performed a retrospective analysis of 131 patients with femoral neck fractures. The operative time, intraoperative blood loss, quality of postoperative fracture reduction, and follow-up observation of fracture healing, screw retreatment rates and fixation failure rates, as well as femoral head necrosis rates and hip function in two groups with 3CCS and 3CCS + mFNSS were compared. By the biomechanical study, we found that 3CCS + Mfnss group were biomechanically superior to 3CCS group and superior to the DHS group in terms of resistance to torsion. However, it was less effective than the DHS group in compressive strength and fatigue resistance. In terms of clinical application, 3CCS + mFNSS group was found to have lower screw retreatment rates and femoral head necrosis rates, and to have better fracture healing rates than group with 3CCS, indicating that medial support screws can effectively resist the vertical shear forces of fracture ends and promote the stability and healing of fracture ends, as well as to reduce the incidence of postoperative complications.

Blood biomarkers related to osteonecrosis of femoral head by internal fixation after Garden I femoral neck fracture: a cohort study

BACKGROUND

Internal fixation is currently considered the gold standard in treatment for femoral neck fractures in adults. However, osteonecrosis of the femoral head (ONFH) after internal fixation would occur in quite proportion of patients with femoral neck fracture, even in Garden I femoral neck fracture. The purpose of this study was to determine the association between the blood biomarkers (serum albumin, pre-albumin, total protein and total lymphocyte count) and ONFH following internal fixation of Garden I femoral neck fracture in adults.

METHOD

This is a single center cohort study, in which each patient who sustained a Garden I femoral neck fracture had been treated with internal fixation, and had adequate preoperative blood examinations. The serum albumin was categorized as ≥ 40g/L or < 40g/L. The pre-albumin was categorized as ≥ 22mg/dL or < 22mg/dL. The total protein was categorized as ≥ 65g/L or < 65 g/L. The total lymphocyte count was categorized as ≥1.1× 10⁹ /L or <1.1×10⁹ /L. Multivariate cox proportional hazards analysis was used to assess the association between blood markers and the osteonecrosis of femoral head during the 2-years follow-up period controlling the confounders.

RESULT

A total of 10 cases of ONFH were identified. Multivariate Cox regression analysis revealed that low total lymphocyte count and hypertension state were significant independent risk factors for ONFH after internal fixation for Garden I femoral head fractures.

CONCLUSION

Blood biomarkers were potential predictors for ONFH after internal fixation Garden I femoral neck fractures. We suggest that routine laboratory tests might can be used to assist surgeons to identify patients at great risk of ONFH.

Comparison of Early Clinical Results for Femoral Neck System and Cannulated Screws in the Treatment of Unstable Femoral Neck Fractures

Objective

To compare early clinical effects of the femoral neck system (FNS) and three cannulated screws for the treatment of patients with unstable femoral neck fractures.

Methods

A retrospective analysis with pair matching of 81 patients who received FNS or cannulated screw internal fixation for Pauwels type‐3 femoral neck fracture in our hospital from January 2019 to December 2019 was conducted. Patients who received FNS were the test group, and those who received cannulated screws comprised the control group. Matching requirements were as follows: same sex, similar age, and similar body mass index (BMI). A total of 30 pairs were successfully matched at a 1:1 ratio, including 12 males and 18 females. The average age of the patients in the FNS group was 54.53 ± 6.71 years. In the cannulated screw group, the average age of the patients was 53.14 ± 7.19 years. The operation time, intraoperative blood loss, hospital stay, hospitalization cost, postoperative visual analog scale (VAS) score, time to walking without crutches, Harris score, femoral head necrosis rate, and complication rate were compared between the groups.

Results

Postoperative re‐examination of radiographs showed satisfactory reduction in all patients, and all patients were followed up for 10–22 months. Those in the FNS group had lower postoperative VAS scores, earlier times to walking without crutches, higher Harris scores at the last follow‐up, and lower complication rates (P < 0.05). VAS scores were lower in the FNS group (3.13 ± 1.07 scores) than in the cannulated screw group (3.77 ± 1.04 scores) (P = 0.018). Patients in the FNS group (5.23 ± 1.33 months) recovered to walking without crutches earlier than did those in the cannulated screw group (6.03 ± 1.45 months) (P<0.001). In addition, a statistically higher postoperative Harris score was detected in the FNS group (86.16 ± 7.26) than in the cannulated screw group (82.37 ± 7.52) (P = 0.039). Overall, a higher incidence of complications was observed in the cannulated screw group (9/30) than in the FNS group (2/30) (P = 0.042). However, intraoperative blood loss and hospitalization costs were greater in the FNS group (P < 0.05). Intraoperative blood loss was greater in the FNS group (99.73 ± 4.69) than in the cannulated screw group (30.27 ± 9.04) (P<0.001). In addition, patients in the FNS group (46976 ± 2270 ¥) spent more on hospitalization costs than did those in the cannulated screw group (15626 ± 1732 ¥) (P<0.001). No statistically significant difference in operation time, hospital stay, or femoral head necrosis rate was observed between the two groups (P > 0.05).

Conclusion

For patients with unstable femoral neck fractures, FNS has better clinical efficacy than cannulated screws, though it is also more expensive.

Clinical observation and finite element analysis of cannulated screw internal fixation in the treatment of femoral neck fracture based on different reduction quality

Objective

Femoral neck fracture is one of the most common bone types. The effect of reduction quality on hip joint function and complications after screw internal fixation is not fully understood. To investigate the clinical efficacy and mechanical mechanism of positive buttress, anatomical reduction, and negative buttress in the treatment of femoral neck fracture after cannulated screw fixation.

Methods

Retrospective analysis of patients with femoral neck fracture treated with three cannulated screws internal fixation in our hospital from January 2013 to December 2018. According to the quality of fracture reduction, the patients were divided into positive buttress group, anatomical reduction group, and negative buttress group. Basic information such as injury mechanism, time from injury to surgery, Garden classification and Pauwels classification was collected, Harris scores were performed at 3 months, 6 months, and 12 months after surgery, and postoperative complications (femoral head necrosis, femoral neck shortening, and femoral neck nonunion) were collected. At the same time, three groups of finite element models with different reduction quality were established for stress analysis, their stress clouds were observed and the average displacement and stress of the three groups of models were compared. P < 0.05 was used to represent a statistically significant difference.

Results

A total of 225 cases of unilateral femoral neck fractures were included and followed up for an average of 4.12 ± 0.69 years. There was no significant difference in age, gender, side, injury mechanism, time from injury to surgery, BMI, Garden classification, Pauwels classification, and follow-up time among the three groups (P > 0.05). However, there was significant difference in Harris score at 6 and 12 months after operation among the three groups (P < 0.05), which was higher in the positive buttress group and anatomical reduction group than in the negative buttress group. In addition, the incidence of osteonecrosis of the femoral head in the negative buttress group (32.2%) was greater than that in the anatomical reduction group (13.4%) and the positive buttress group (5.4%) (P < 0.05). In addition, the incidence of femoral neck nonunion and femoral neck shortening in the negative buttress group was also higher than that in the anatomical reduction positive buttress group (P < 0.05). The finite element results showed that the stress and fracture end displacement in the negative buttress group were greater than those in the positive buttress group (P < 0.05).

Conclusion

Both positive buttress and anatomical reduction in the treatment of femoral neck fracture with cannulated screw internal fixation can obtain better clinical effect and lower postoperative complications. Positive brace support and anatomic reduction can limit the restoration of femoral stress conduction. Therefore, it is not necessary to pursue anatomical reduction too deliberately during surgery, while negative buttress reduction should be avoided.

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.

Prediction of femoral head avascular necrosis following femoral neck fracture: "pin-tract sign" of 99mTc-HDP pinhole bone scan after metallic fixation

OBJECTIVE

To evaluate the predicting value of ^99mTc-hydroxydiphosphonate (HDP) pinhole bone scan in development of osteonecrosis of femoral head (ONFH) in patients with femoral neck fracture after cannulated screw fixation.

METHODS

Pinhole bone scan of patients with metallically fixed femoral neck fracture from 2001 to 2015 were retrospectively reviewed. Initial pinhole bone scan was obtained within 2-3 weeks after surgery. Findings of initial pinhole bone scan were divided in to 4 groups. Group CU included cold defect in affected femoral head, group HU with no cold defect. Group PP with increased uptake along the inserted screws and group PN with no increased uptake along the inserted screws. More than 6 months of follow-up with pinhole bone scan and clinico-radiological evidence for ONFH was reviewed.

RESULTS

72 patients (mean age 54.01 years, male 22, female 50) were included. 19 patients were in group CU, 53 in group HU. 60 patients were in group PP, 12 in group PN. During the follow-up, 13 patients were diagnosed as ONFH. 9 (47.36%) patients in group CU developed ONFH and 4 (7.5%) in group HU. 4 (6.66%) patients in group PP developed ONFH and 9 (75%) in group PN.

CONCLUSIONS

To predict ONFH of femoral head followed by neck fracture, many imaging techniques with variable results were known. In this study, cold defect in early postoperative pinhole bone scans could predict ONFH, and loss of increased uptake along screw inserted site could be a strong indicative sign of ONFH. Further evaluation with a larger population is necessary.

Osteonecrosis of femoral head in young patients with femoral neck fracture: a retrospective study of 250 patients followed for average of 7.5 years

Objective

To investigate the risk factors for osteonecrosis of the femoral head (ONFH) after the treatment of femoral neck fracture in patients under 60 years old.

Methods

A total of 250 cases of femoral neck fracture treated at 3 hospitals in Xuzhou from January 2002 to January 2016 were studied. The patients were followed up for 1~15 years, and the clinical data on femoral head necrosis after the femoral neck operation were analysed retrospectively. Risk factors were recorded, including age, gender, preoperative traction, time from injury to operation, reduction method, type of reduction, BMI, ASA classification, and quality of reduction. Logistic regression analysis was used to evaluate the independent risk factors for ONFH after treatment of femoral neck fracture.

Results

The duration of follow-up was 1~15 years, with an average of 7.5 years. None of the 250 patients had fracture non-union, but 40 (16%) had necrosis of the femoral head. The time to necrosis of the femoral head was 1~7 years after the operation, with an average of 3.8 years. Univariate analysis showed that the type of fracture, the quality of reduction, the removal of internal fixation, BMI and ASA classification were risk factors affecting necrosis of the femoral head in patients with femoral neck fracture, and the difference was statistically significant (P < 0.05). Multivariate analysis showed that internal fixation, fracture type (displacement), reduction quality (dissatisfaction), BMI (> 25), and ASA grade (III + IV) were independent risk factors affecting femoral head necrosis in patients with femoral neck fracture.

Conclusion

A variety of high-risk factors for femoral head necrosis are present after surgery with hollow compression screws for femoral neck fracture in adults. Removal of internal fixation, type of fracture, quality of reduction, BMI, and ASA classification were the most important risk factors influencing the development of femoral head necrosis. During treatment, there should be some targeted measures to reduce the incidence of necrosis of the femoral head.

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.

Efficacy of extracorporeal shock wave combined spinal core decompression for the treatment of patients with femoral head necrosis: A protocol for systematic review and meta-analysis

BACKGROUND

Previous studies have reported that extracorporeal shock wave (EPSW) combined spinal core decompression (SCD) has been used for the treatment of patients with femoral head necrosis (FHN) effectively. However, their results are still inconsistent. Therefore, this study will systematically assess the efficacy and safety of EPSW and SCD for the treatment of patients with FHN.

METHODS

This study will systematically search the following databases from inception through March 1, 2020: MEDLINE, Web of Science, Scopus, EMBASE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, and China National Knowledge Infrastructure. All searches will be performed without language and publication date restrictions. This study will only include randomized controlled trials investigating the efficacy and safety of EPSW and SCD for the treatment of patients with FHN. Two authors will independently assess all literatures, extract data, and appraise risk of bias. Any confusion between 2 authors will be cleared up by a third author through discussion. RevMan 5.3 software will be utilized to analyze the data and to perform a meta-analysis if necessary.

RESULTS

This study will summarize up-to-date evidence and provide a detailed summary related to the efficacy and safety of EPSW and SCD for the treatment of patients with FHN.

CONCLUSION

This study may provide helpful evidence to determine whether or not EPSW combined SCD is effective and safety for the treatment of patients with FHN.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202040092.

Dynamic compression locking system versus multiple cannulated compression screw for the treatment of femoral neck fractures: a comparative study

BACKGROUND

Femoral neck fractures are one of the problems in clinical treatment. The prognosis is uncertain. Currently, No internal fixation method is superior to other internal fixation methods in the treatment of femoral neck fractures. Therefore, the internal fixation system needs to be further explored. The aim of this study was to compare clinical outcomes of femoral neck dynamic compression locking system (DCLS) and multiple cannulated compression screws(MCCS) in the treatment of femoral neck fractures.

METHODS

A prospective analysis of 54 cases of femoral neck fractures treated with either a DCLS (n = 28) or MCCS (n = 26) was conducted between December 2015 and November 2017 in authors' hospitals. The perioperative and postoperative parameters of the two groups were recorded and evaluated.

RESULTS

Fifty-four patients were followed up for 24-47 months. The etiology was caused by a fall. There was no significant difference in follow-up time, operation time, incision length, surgical blood loss, the incidence of perioperative and postoperative healing complications, and mobility in the two groups (all P > 0.05). The Harris score, fracture healing time, femoral neck shortening, partial weight-bearing time and complete weight-bearing time were significantly better in the DCLS group than in the MCCS group (all P < 0.05). The fracture healing rate in the DCLS group was higher than that in the MCCS group.

CONCLUSIONS

The DCLS and MCCS might be equally effective in terms of operation time, incision length, surgical blood loss, the incidence of perioperative and postoperative healing complications, and mobility in the treatment of femoral neck fractures. However, the DCLS is superior to the MCCS in Harris score, fracture healing time, femoral neck shortening, weight-bearing time and fracture healing rate. So, DCLS deserves further study.

Risk Factors for Functional Outcomes of the Elderly with Intertrochanteric Fracture: A Retrospective Cohort Study

Objective

To identify baseline factors relevant to functional outcomes and health‐related quality of life in the elderly with intertrochanteric fractures.

Methods

For the present study, 168 patients with intertrochanteric fracture who were assigned to different treatments between January 2016 and December 2017 were retrospectively selected. Hip function was assessed by Harris hip score (HHS), and health‐related quality of life was evaluated by Barthel index (BI) of activities of daily living (ADL) and EuroQol 5‐dimensions (EQ‐5D) score, respectively. Data were analyzed by t‐test, ANOVA, Pearson's correlation, χ²‐test, and multivariate linear regression.

Results

A total of 164 (97.6%) patients completed the follow‐up, with an average follow‐up time of 15.7 ± 6.9 months; 39 (23.8%) patients died during the follow‐up period and 125 (76.2%) patients were eligible for the functional analysis. HHS at final follow‐up of 125 patients was 71.8 ± 13.1, and the following were associated with hip functional recovery: age (−0.45, 95% confidence interval (CI) −0.73 to −0.18, P < 0.01), serum albumin (0.65, 95% CI 0.04 to 1.27, P < 0.05), and ADL at discharge (0.18, 95% CI 0.01 to 0.33, P < 0.05). The Barthel index at final follow up in this cohort was 80.2 ± 18.1, and multivariable linear regression analysis showed that age (−0.49, 95% CI −0.85 to −0.12; P < 0.05), ADL score at discharge (0.29, 95% CI 0.07 to 0.51; P < 0.05) and internal fixation (16.3, 95% CI 3.3 to 29.3; P < 0.05) were associated with ADL at final follow‐up. EQ‐5D at final follow‐up was 0.74 ± 0.2, with which HHS (0.012, 95% CI 0.011 to 0.013; P < 0.01) was positively associated.

Conclusion

We identify several baseline factors associated with hip functional outcome, health utility, and ADL in the elderly after an intertrochanteric fracture, of which we could modify mutable factors to achieve better outcomes. These findings could help to inform treatment and functional prognosis.

Risk factors associated with osteonecrosis of femoral head after internal fixation of femoral neck fracture:a systematic review and meta-analysis

BACKGROUND

Although the risk factors associated with osteonecrosis of femoral head (ONFH) after internal fixation of femoral neck fracture (IFFNF) have been frequently reported, the results remain controversial. Therefore, its related risk factors were systematically evaluated and meta-classified in this study.

METHODS

Literature on risk factors of ONFH caused by IFFNF was retrieved in PubMed, Embase and Cochrane Library due June 2019. Review Manager 5.3 software was applied to data synthesis, and Stata 13.0 software was adopted for analyses of publication bias and sensitivity.

RESULTS

A total of 17 case-control studies with 2065 patients were included. The risk of ONFH after IF was 0.40-fold higher in patients with Garden III-IV FNF than that in patients with Garden I-II (OR: 0.40, 95%CI: 0.29-0.55). The risk of OFNH with retained IF was uplifted by 0.04 times (OR: 0.04, 95%CI: 0.02-0.07). There was nonsignificant relationship between gender and ONFH after IFFNF (OR: 1.27, 95%CI: 0.84-1.94). Moreover, ONFH after IFFNF presented no association with age (OR:1.66, 95%CI: 0.89-3.11), injury-operation interval (OR:1.29, 95%CI: 0.82-2.04), fracture reduction mode (OR:1.98, 95%CI: 0.92-4.26), preoperative traction (OR:1.69, 95%CI: 0.29-9.98) and mechanism of injury (OR:0.53, 95%CI: 0.06-4.83). Egger's and Begg's tests indicated a publication bias (P = 0.001).

CONCLUSION

It was demonstrated that Garden classification and retained IF were important influencing factors of ONFH after IFFNF. Gender, age, injury-operation interval, fracture reduction mode, preoperative traction and the mechanism of ONFH were irrelevant to the complication.

Three-dimensional analyses to predict surgical outcomes in non-displaced or valgus impaction fractures of the femoral neck: A multicenter retrospective study

INTRODUCTION

The aim of our study was to (1) report our surgical outcomes of internal fixation in patients with non-displaced or valgus impaction fractures of the femoral neck, (2) introduce our new three-dimensional assessment method using a combination of X-ray and CT imaging, and (3) determine which radiologic measurements significantly predicted fixation failure.

HYPOTHESIS

We hypothesized that high posterior tilt angle and retroversion angle are related to high incidence of non-union and osteonecrosis.

MATERIALS AND METHODS

From January 2009 to December 2016, 64 elderly patients in two institutions with non-displaced or valgus impaction fractures of the femoral neck who had internal fixation using multiple parallel cannulated screws were enrolled. To determine the independent predictors of non-union, osteonecrosis, and re-operation, various clinical variables and radiologic variables, including the valgus angle on coronal CT images, the posterior tilt angle on Lorenz images, and the retroversion angle on axial CT images, were analyzed.

RESULTS

Non-union was identified in nine of the 64 patients (14.1%) and nine of the 55 patients (16.4%) who achieved bony union had femoral head osteonecrosis with subsequent segmental collapse. The multiple logistic regression model showed that a low bone mineral density of the femur, a higher posterior tilt angle on Lorenz image, and a higher retroversion angle on axial CT images were independent predictors of non-union and re-operation.

DISCUSSION

Primary hip arthroplasty should be considered when a posterior tilt angle of more than 9 degrees on Lorenz images or a retroversion angle of more than 13 degrees on axial CT images is identified in patients with osteoporotic valgus impaction fractures.

TYPE OF STUDY AND LEVEL OF PROOF

III, Retrospective comparative study.

Femoral neck shortening after internal fixation of Garden I fractures increases the risk of femoral head collapse

BACKGROUND

Arthroplasty has not been proven superior over internal fixation for the treatment of non-displaced femoral neck fractures. However, internal fixation has been followed by high rates of revision for mechanical complications and of femoral neck impaction within the first postoperative year. The objective of this study was to determine whether femoral neck impaction was associated with avascular necrosis (AVN).

HYPOTHESIS

Fracture healing with femoral neck shortening by impaction after internal fixation of a femoral neck fracture is associated with AVN.

MATERIAL AND METHODS

A single-centre retrospective study in patients with Garden I fractures managed by screw fixation was performed to compare outcomes in the groups with and without femoral neck impaction. Follow-up radiographs were assessed for evidence of the femoral neck impaction during fracture healing. The occurrence of AVN was the primary evaluation criterion. The secondary evaluation criteria were risk factors for impaction and complications.

RESULTS

Of the 75 included patients, 9 (12%) experienced AVN. Impaction was significantly associated with AVN (p=0.02; relative risk, 4.38). Significant risk factors for impaction were a higher body mass index (p=0.0003) and valgus-impacted fracture reduction between the radiographs at baseline and immediately after surgery (p=0.0001).

DISCUSSION

Femoral neck impaction was a significant risk factor for AVN after screw fixation of Garden I fractures. Valgus-impacted fracture reduction must receive careful attention during fixation. We suggest static internal fixation if the impaction is reduced on a traction table and advise caution when using parallel screws. The diagnostic and therapeutic strategy proposed here deserves to be evaluated in a prospective study.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Minimally invasive open reduction combined with proximal femoral hollow locking plate in the treatment of Pauwels type III femoral neck fracture

Objective

This study was performed to investigate the clinical effects of minimally invasive open reduction and internal fixation with a proximal femoral hollow locking plate on Pauwels type III femoral neck fractures.

Methods

The clinical data of 45 patients aged 32.0 ± 8.1 years (range, 19–45 years) with Pauwels type III femoral neck fractures treated from March 2012 to August 2016 were retrospectively analyzed. All patients underwent anterolateral minimally invasive open reduction and proximal femoral hollow locking plate fixation of the hip joint. Garden’s index was used to evaluate the quality of fracture reduction. Complications and fracture healing were recorded in all patients. At the last follow-up, the functional outcome was recorded using the Harris hip score.

Results

No complications such as femoral neck shortening, internal fixation loosening, or refracture occurred. However, three patients required reoperation (one with nonunion and two with femoral head necrosis). At the last follow-up, the mean Harris hip score was 92.1 ± 4.5 (range, 76–98). The rate of excellent and good Harris hip scores was 93.3%.

Conclusion

The herein-described strategy for Pauwels type III femoral neck fractures is advantageous in terms of high reduction quality, firm fixation, and prevention of neck shortening.

A safe percutaneous technique for the reduction of irreducible femoral neck fractures using ultrasound localization of the femoral vascular and nervous structures at the hip

We present a safe percutaneous technique for the placement of Kirschner wires into the femoral head to assist in the reduction of irreducible femoral neck fractures using ultrasound to identify the vascular and nervous structures about the hip.From January 2011 to June 2014, a total of 36 patients (25 males and 11 females) were enrolled in this study. Patients were placed on a fracture reduction table for limb traction. After 3 unsuccessful reductions with limb traction, ultrasound-guided localization of the patient's femoral artery, vein, and nerve at the hip was performed. These structures were marked on the overlying skin and then Kirschner wires were inserted into the femoral head avoiding these marked structures. After the surgery, the Kirschner wire insertions were routinely reviewed by ultrasound, the hip fracture reduction and the femoral nerve sensorimotor function were routinely examined as well.All 36 patients with an irreducible variant of a femoral neck fracture showed anatomic reduction under C-arm fluoroscopy using ultrasound to avoid K wire injury to the femoral vascular structures and nerve. No major vascular injury during operation. In post-surgical ultrasound examination, local hematoma formation was not evident. There was normal function of the femoral nerve. On follow-up, there were no infections, wound problems, recurrence of fracture displacement, laxity, or implant breakage.Preoperative ultrasonic localization of the femoral artery, vein, and femoral nerve safely allowed. Kirschner wire placement under C-arm fluoroscopy into the femoral head to assist in fracture reduction. This assisted reduction method for irreducible femoral neck fractures had a number of advantages, including closed anatomic reduction with minimal attempts, used simple equipment, and avoided further destruction of the blood supply to the femoral head.

Treatment of femoral neck fractures in patients 45-64 years of age

INTRODUCTION

Young patients with femoral neck fractures are optimally treated with reduction and stable fixation, while patients over the age of sixty-five are often treated with arthroplasty. This study analyzes in-hospital outcomes associated with total hip arthroplasty, hip hemiarthroplasty and internal fixation for treatment of femoral neck fractures in patients aged 45-64.

METHODS

Records of patients between the ages of 45-64, from 2002 to 2014, sustaining femoral neck fractures and treated with internal fixation, hip hemiarthroplasty or total hip arthroplasty were obtained from the Nationwide Inpatient Sample (NIS). Examined variables were age, sex and Charlson Comorbidity Index (CCI). Outcome measures included hospital length of stay (LOS), complications, and inpatient hospitalization charge.

RESULTS

From 2002-2014 74,678 femoral neck fractures were available for analysis. THA use increased from 5.3% of operatively managed fractures in 2002 to 22.3% of operatively managed fractures in 2014 (p < 0.0001). Patients undergoing THA had higher hospital cost, higher in hospital complication rates and longer length of stay than patients undergoing internal fixation (p < 0.0001). The in-hospital mortality for patients undergoing a hip hemiarthroplasty was higher (1.2%) than either total hip arthroplasty (0.2%) or internal fixation (0.5%) (P = 0.007).

CONCLUSION

This study demonstrates that the use of total hip arthroplasty in treatment of femoral neck fractures in patients from the age of 45-64 increased 4.2-fold over the study period. This treatment is associated with increased hospital cost, length of stay and complications. Additionally, as age increased in our study population, there was a stepwise increase in the use of arthroplasty, and it appears that hemiarthroplasty is being used with a different patient population.

Using Naive Bayes Classifier to predict osteonecrosis of the femoral head with cannulated screw fixation

Predictive models permitting personalized prognostication for patients with cannulated screw fixation for the femoral neck fracture before operation are lacking. The objective of this study was to train, test, and cross-validate a Naive Bayes Classifier to predict the occurrence of postoperative osteonecrosis of cannulated screw fixation before the patient underwent the operation. The data for the classifier model were obtained from a ambispective cohort of 120 patients who had undergone closed reduction and cannulated screw fixation from January 2011 to June 2013. Three spatial displaced parameters of femoral neck: displacement of centre of femoral head, displacement of deepest of femoral head foveae and rotational displacement were measured from preoperative CT scans using a 3-dimensional software. The Naive Bayes Classifier was modelled with age, gender, side of fractures, mechanism of injury, preoperative traction, Pauwels angle and the three spatial parameters. After modelling, the ten-fold cross-validation method was used in this study to validate its performance. The ten-fold cross-validation method uses the whole dataset to be trained and tested by the given algorithm. Two of the three spatial parameters of femoral neck (displacement of center of femoral head and rotational displacement) were included successfully in the final Naive Bayes Classifier. The Classifier achieved good performance of the accuracy (74.4%), sensitivity (74.2%), specificity (75%), positive predictive value (92%), negative predictive value (42.9%) and AUC (0.746). We showed that the Naive Bayes Classifier have the potential utility to be used to predict the osteonecrosis of femoral head within 5 years after surgery. Although this study population was restricted to patients treated with cannulated screws fixation, Bayesian-derived models may be developed for application to patients with other surgical procedures at risk of osteonecrosis.

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.

The clinical application of a novel method of internal fixation for femoral neck fractures-dynamic locking compression system

Background

Femoral neck fractures are the commonly encountered injury in orthopedic practice and result in significant morbidity and mortality. Currently, how to treat femoral neck fractures safely and effectively is still a challenge. The objective of this study is to evaluate the efficiency of dynamic compression locking system for femoral neck fractures.

Methods

This is a retrospective study conducted from May 2015 to October 2016. The study included 36 patients suffering from femoral neck fractures who underwent closed reduction and were fixed using dynamic compression locking system. All surgeries were performed by the same surgeon. The study was conducted by telephone and on-site follow-up. The Garden classification and anatomical site classification were categorized for all patients. We assessed radiographic outcomes of union, femoral neck shortening, screw back-out, and femoral head avascular necrosis. We also evaluated functional outcome using the Harris hip score. Other outcomes included the length of surgery, duration of hospital stay, injury to surgery time, intraoperative hemorrhage, time to clinical bone union, and other fracture complications.

Results

All patients were followed up 12 to 29 months with an average of 21.58 ± 5.41 months. All cases were caused by falls including 17 males and 19 females with an average age of 65.33 ± 9.30 years old ranging from 53 to 82 years old. Among them, injury to surgery time ranged between 1 and 4 days with an average of 2.58 ± 1.05 days. Duration of hospital stay was 8 to 21 days with an average of 15.33 ± 3.71 days. Intraoperative hemorrhage was 40 to 80 ml with an average of 61.67 ± 12.31 ml. Operation time was from 35 to 80 min with average of 50.25 ± 11.77 min. According to Garden classification, 9 cases (25%) were type II and 27 cases (75%) were type III. According to the anatomical site classification, 8 cases (22.2%) were subcapital femoral neck fractures, 19 cases (52.8%) trans-cervical, and 9 cases (25%) basi-cervical. At present, the follow-up has not found the fracture complications of femoral head avascular necrosis, fracture nonunion, and re-fracture. All patients achieved solid bone union. The mean time of clinical bone union was 3 to 4 months. Among all patients, there were only 3 cases of femoral neck shortening < 5 mm and 1 case of screw back-out = 4 mm. For Harris scoring, average Harris scale at the end of the follow-up was 93.42 ± 3.95 ranging from 85 to 98. There were 32 cases of excellent function scores on the Harris scale and 4 cases of good function scores on the Harris scale. Therefore, the excellent and good rate of Harris hip scores was 100%.

Conclusions

Femoral neck dynamic compression locking system for femoral neck fractures in elderly patients can provide effective stability and reduce complications and revision rates.

Femoral shortening does not impair functional outcome after internal fixation of femoral neck fractures in non-geriatric patients

INTRODUCTION

Aim of this study was to investigate the incidence and extent of femoral shortening in non-geriatric patients after internal fixation of femoral neck fractures in relation to the clinical outcome at mid-term follow-up.

MATERIALS AND METHODS

Reviewing our admission data, we identified non-geriatric patients (18-65 years) with femoral neck fractures treated with either dynamic hip screw or cancellous screws between 2007 and 2015. Patients were then contacted and invited to a follow-up clinical investigation including whole-leg standing X-rays.

RESULTS

A total of 40 patients with a mean age at surgery of 52 ± 9 years returned for the follow-up examination. Overall, 31 patients (77.5%) had undergone a dynamic hip screw fixation, while 9 patients were treated with cancellous screws (22.5%). The median follow-up time was 65.5 months (5.5 years). We observed shortening of the ipsilateral femur neck in the majority of cases (92.5%). Still, functional outcome in the overall study population was excellent with a median Harris Hip Score of 96.

CONCLUSIONS

Femoral neck shortening is common in non-geriatric patients after internal fixation of femoral neck fractures. Nonetheless, observed excellent functional outcome at mid-term follow-up supports joint-preserving strategies in non-geriatric femoral neck 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.

Bone Microarchitecture and Biomechanics of the Necrotic Femoral Head

The mechanism behind osteonecrosis of the femoral head (ONFH) remains unclear. The aim of this study was to explore the pathogenesis of ONFH from a biomechanical standpoint to provide a theoretical basis for improved treatments. We compared the bone structure of fractured femoral heads with that of necrotic femoral heads by Micro-CT scanning and histological evaluation. In addition, we compared the biomechanical properties of each zone in fractured femoral heads with those in necrotic femoral heads by using biomechanical tests. Compared with fractured femoral heads, bone microarchitecture and bone morphometry in necrotic zone and sclerotic zone of necrotic femoral heads have altered markedly. In addition, the biomechanical properties of the necrotic zone in femoral heads weaken markedly, while those of the sclerotic zone strengthen. We hypothesize that discordance between bone structure and function of the femoral head may be involved in the pathogenesis of ONFH and that more attention should be paid to the prevention and treatment of such discordance.

Interventions for treating displaced intracapsular femoral neck fractures in the elderly: a Bayesian network meta-analysis of randomized controlled trials

Displaced intracapsular femoral neck (AO type 31 B2/3) fractures have various treatments, including internal fixation (IF), unipolar uncemented hemiarthroplasty (HA), bipolar uncemented HA, unipolar cemented HA, bipolar cemented HA, uncemented total hip replacement (THR), and cemented THR. Systematic literature retrieval was performed from the databases to compare them in a network meta-analysis. Forty studies (85 arms) containing 6141 patients were included. Overall, our network meta-analysis rank the orders of 7 procedures in reoperation, mortality, dislocation and infection, which indicates that IF may provide the highest reoperation incidence, unipolar cemented HA may provide the lowest reoperation incidence; uncemented THR contributes the highest dislocation incidence; and bipolar uncemented HA provides the lowest infection incidence. No differences in mortality were observed among the treatments. This conclusion is indirect; higher-quality direct comparisons are required.

DHS osteosynthesis with internal bone grafting in unstable delayed presented intracapsular neck femur fractures

OBJECTIVES

The aim of this study was to assess fracture union and complications following use of dynamic hip screw (DHS) with internal bone grafting in treatment of unstable delayed presented intracapsular neck femur fractures in patients younger than 65 years of age.

MATERIAL AND METHODS

Thirty two patients with displaced intracapsular neck femur fractures(Garden III and IV, Pauwels III, with comminution) with delayed presentation (15-60 days) in the 45-65 year age group (mean 54.4±10.2 years) were included in this study. All patients were treated with dynamic sliding hip screw with closed cancellous bone grafting through a tunnel of a triple reamer. The average time to union was 3.8 months (3-5 months). Satisfactory union was achieved in all patients except two. One case developed avascular necrosis of the femoral head. Other complications were coxa vara in two, shortening of less than 10mm in three cases but there were no cases of infection or implant failure. Excellent results were achieved in 27, good/fair in 4 and poor in 1 patient.

CONCLUSION

Osteosynthesis with DHS and primary cancellous bone grafting in indicated cases is a simple, providing biological stimulation for early union. Failure in a particular case can be treated with any appropriate second procedure.

The efficacy of pregabalin for the management of postoperative pain in primary total knee and hip arthroplasty: a meta-analysis

Objective

A systematic review of randomized controlled trials (RCTs) was conducted to evaluate the efficacy of pregabalin for the management of postoperative pain in patients undergoing primary total knee arthroplasty (TKA) and primary total hip arthroplasty (THA).

Method

The PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched for related articles using search strategy. RevMan 5.3 software was selected to conduct the meta-analysis.

Results

Seven RCTs were included in our meta-analysis. There were significant differences in visual analogue scale (VAS) at 24 and 48 h with rest, knee flexion degree, mean morphine consumption, and postoperative side effects (nausea, vomiting, pruritus, and dizziness) when comparing the pregabalin group to the placebo group after TKA and THA. However, the differences in VAS at 72 h with rest and at 24 h on movement were not significant between the two groups.

Conclusions

Pregabalin was found to improve pain control at 24 and 48 h with rest, reduce morphine consumption, improve the knee flexion degree, decrease the incident rate of nausea, vomiting, and pruritus, and increase the incident rate of dizziness after TKA and THA but could not improve the pain control at 72 h with rest. In summary, the use of pregabalin may be a valuable asset in pain management within the first 48 h after TKA and THA. However, future studies regarding doses and pregabalin medication are required.

Pathophysiology and risk factors for osteonecrosis

Osteonecrosis, also known as avascular necrosis or AVN, is characterized by a stereotypical pattern of cell death and a complex repair process of bone resorption and formation. It is not the necrosis itself but rather the resorptive component of the repair process that results in loss of structural integrity and subchondral fracture. Most likely, a common pathophysiological pathway exists involving compromised subchondral microcirculation. Decreased femoral head blood flow can occur through three mechanisms: vascular interruption by fractures or dislocation, intravascular occlusion from thrombi or embolic fat, or intraosseous extravascular compression from lipocyte hypertrophy or Gaucher cells. In this review, we emphasize etiologic relationships derived mostly from longitudinal cohort studies or meta-analyses whose causal relationships to osteonecrosis can be estimated with confidence. Understanding risk factors and pathophysiology has therapeutic implications since several treatment regimens are available to optimize femoral head circulation, interrupt bone resorption, and preserve the subchondral bone.