Evidence based management of intracapsular neck of femur fractures

The significance of reduction of valgus-intercalated femoral neck fracture with valgus angle > 15°and the selection of internal fixation by finite element analysis

BACKGROUND

Currently, consensus is lacking on the necessity of internal fixation after reducing valgus-intercalated femoral neck fractures with abduction > 15°. This study employs finite element analysis to compare the biomechanical differences between the femoral neck dynamic cross nail system (FNS) and inverted cannulated screw (ICS), aiming to provide a foundation for clinical procedures.

METHODS

Human femur CT scan data were processed using MimICS21.0 and Geomagic 2021 software, imported into Solidworks2021 to create fracture models, based on Garden I abduction and Valgus-intercalated femoral neck fractures. The internal fixation model was divided into two groups: A-Anatomic reduction group; B-Valgus-intercalated femoral neck fracture group. ANSYS software facilitated meshing, material assignment, and data calculation for stress and displacement comparisons when ICS and FNS were applied in reduction or non-reduction scenarios.

RESULTS

Without internal fixation, peak femur stress in both groups was 142.93 MPa and 183.62 MPa. Post FNS fixation, peak stress was 254.11 MPa and 424.81 MPa; peak stresses for the two FNS models were 141.26 MPa and 248.33 MPa. Maximum displacements for the two FNS groups were 1.91 mm and 1.26 mm, with peak fracture-end stress at 50.751 MPa and 124.47 MPa. After ICS fixation, femur peak stress was 204.76 MPa and 274.08 MPa; maximum displacements were 1.53 mm and 1.15 mm. ICS peak stress was 123.88 MPa and 174.61 MPa; maximum displacements were 1.17 mm and 1.09 mm, with peak fracture-end stress at 61.732 MPa and 104.02 MPa, respectively.

CONCLUSIONS

Our finite element study indicates superior mechanical stability with internal fixation after reducing valgus-intercalated femoral neck fractures (> 15°) compared to in situ fixation. Additionally, ICS biomechanical properties are more suitable for this fracture type than FNS.

Bone Grafting Can Promote the Prognosis of Displaced Femoral Neck Fractures: A Follow-up of the Clinical Significance of Bone Defects

Background

Femoral neck fractures (FNFs) comprise a large proportion of osteoporotic fractures in Asia. However, the full range of prognostic variables that affect prognosis remains unclear. Here, we aimed to determine whether the severity of bone defects at the fracture site and other variables impact the prognosis of displaced FNFs.

Methods

We evaluated the incidence of FNF internal fixation failures at regular intervals after surgery in data collected retrospectively. Digital Imaging and Communications in Medicine (DICOM) magnetic resonance imaging data of the displaced FNFs of 204 patients (> 20 years old; mean age, 52.3 years; men, 55.4%) who underwent internal fixation were used to construct three-dimensional (3D) virtual models of the femoral neck region. We calculated the position and volume of bone defect (VBD) using our independently developed algorithm and Mimics software. Each participant was followed up for at least 24 months; complications were noted and correlated with VBD and demographic and clinical variables.

Results

On the basis of VBD values calculated from virtual reduction models, 57 patients were categorized as having a mild defect, 100 as having a moderate defect, and 47 as having a severe defect. Age (p = 0.046) and VBD (p < 0.001) were significantly correlated with internal fixation failure. Multivariate analysis revealed that severe bone defects were associated with internal fixation failure (adjusted odds ratio [aOR], 23.073; 95% confidence interval [CI], 2.791-190.732) and complications (aOR, 8.945; 95% CI, 1.829-43.749). In patients with a severe defect, bone grafting was inversely associated with internal fixation failure (aOR, 0.022; 95% CI, 0.002-0.268) and complications (aOR, 0.023; 95% CI, 0.002-0.299).

Conclusions

Bone defect severity was associated with internal fixation failure and other complications. For young adults with large VBDs, bone grafting of the defect can reduce the risk of internal fixation failure. These results provide useful new quantitative information for precisely classifying displaced FNFs and guiding subsequent optimal treatments.

[Femoral neck fractures]

Femoral neck fractures (FNF) are the most frequent fractures in the older population and are also of high socioeconomic importance due to the high risk of mortality. The diagnostics are based on the clinical examination and imaging procedures. The classification systems used in the routine clinical practice are oriented towards the prognosis and are therefore a valuable aid in making decisions for the selection of the treatment procedure. Early surgery is decisive for the success of treatment. Older patients (> 60 years) with arthritically damaged hips and a high degree of fracture dislocation benefit from prompt hip replacement (bipolar systems, total hip arthroplasty, dual mobility systems). In contrast, joint-preserving surgery by osteosynthesis is indicated in younger patients with a low degree of dislocation. This article summarizes the clinically relevant aspects of FNF and gives an overview of current treatment strategies with inclusion of the scientific literature.

Is the Revision Rate for Femoral Neck Fracture Lower for Total Hip Arthroplasty Than for Hemiarthroplasty?: A Comparison of Registry Data for Contemporary Surgical Options

BACKGROUND

When arthroplasty is indicated for a femoral neck fracture (FNF), it is unclear whether total hip arthroplasty (THA) or hemiarthroplasty (HA) is best. This study compares data from the Australian Orthopaedic Association National Joint Replacement Registry using contemporary surgical options.

METHODS

Patients from 60 to 85 years old who were treated with arthroplasty for FNF, between September 1999 and December 2019, were included if the femoral stems were cemented. Only THAs with femoral heads of ≥36 mm or dual-mobility articulations were included. Patients who had monoblock HA were excluded. Rates of revision for all aseptic failures and dislocation were compared. Competing risks of revision and death were considered using the cumulative incidence function. Subdistribution hazard ratios (HRs) for revision or death from a Fine-Gray regression model were used to compare THA and HA. Interactions of procedure with age group and sex were considered. Secondary analysis adjusting for body mass index (BMI) and American Society of Anesthesiologists (ASA) classification was also considered.

RESULTS

There were 4,551 THA and 29,714 HA procedures included. The rate of revision for THA was lower for women from 60 to 69 years old (HR = 0.58 [95% confidence interval (CI), 0.39 to 0.85]) and from 70 to 74 years old (HR = 0.65 [95% CI, 0.43 to 0.98]) compared with HA. However, women from 80 to 85 years old (HR = 1.56 [95% CI, 1.03 to 2.35]) and men from 75 to 79 years old (HR = 1.61 [95% CI, 1.05 to 2.46]) and 80 to 85 years old (HR = 2.73 [95% CI, 1.89 to 3.95]) had an increased rate of revision when THA was undertaken compared with HA. There was no difference in the rate of revision for dislocation between THA and HA for either sex or age categories.

CONCLUSIONS

When contemporary surgical options for FNF are used, there is a benefit with respect to revision outcomes for THA in women who are <75 years old and a benefit for HA in women who are ≥80 years old and men who are ≥75 years old. There is no difference in dislocation rates.

LEVEL OF EVIDENCE

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

Mortality associated with cemented and uncemented fixation of hemiarthroplasty and total hip replacement in the surgical management of intracapsular hip fractures: A systematic review and meta-analysis

BACKGROUND

The use of bone cement for implant fixation in the surgical management of intracapsular hip fractures (IHFs) remains controversial. Although UK national guidance supports cementation, many surgeons remain cautious of its use. In this systematic review and meta-analysis, we aimed to evaluate evidence surrounding post-operative mortality associated with cemented and uncemented total hip replacement and hemiarthroplasty implants.

METHODS

We conducted a search of MEDLINE and Embase databases for randomised controlled trials (RCTs) from commencement until 17 June 2020. Articles reporting mortality or patient survival as an outcome following total hip replacement (THR) or hemiarthroplasty (HA) to manage IHFs were included. Articles not comparing cemented and uncemented fixation were excluded. A meta-analysis on mortality stratified by post-operative follow-up period was conducted using a fixed-effects model. The Revised Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias.

RESULTS

Our initial search found 77 references, 13 of which were eligible for full-text review. Mortality data from 12 studies were pooled and included in the meta-analysis. 1 599 operations were reported: 882 involved cemented fixation; 717, uncemented. Mortality outcome reporting ranged from less than 7 days to 5 years post-operation. No significant difference was observed between the two groups in mortality at any follow-up period. Study quality assessment revealed low certainty in mortality estimates.

CONCLUSION

Existing evidence indicates that cementation has no effect on mortality at any reported follow-up time period. Even with the use of evidence synthesis, the sample size remains relatively low for mortality outcomes and insufficiently powered to reliably determine differences between groups.

Hip Hemiarthroplasty for Fractured Neck of Femur Revised to Total Hip Arthroplasty: Outcomes Are Influenced by Patient Age Not Articulation Options

BACKGROUND

Hip hemiarthroplasty is the most common arthroplasty option for fractured neck of femur (FNOF). Revision to total hip arthroplasty (THA) is occasionally required. This study aimed to assess the outcome of hemiarthroplasty revised to THA and to assess the impact of femoral head size, dual mobility (DM), and constrained liners.

METHODS

All aseptic 1^st revisions reported to the Australian Joint Replacement Registry after hemiarthroplasty performed for FNOF when a THA was used as the revision procedure were included from September 1999 to December 2019. The primary outcome measure was the cumulative percent revision for all-causes and dislocation. The impact of prosthesis factors on revision THA was assessed: standard head THA (≤32 mm), large head THA (≥36 mm), DM, and constrained liners. Outcomes were compared using Kaplan Meyer and competing risk.

RESULTS

There were 96,861 hemiarthroplasties performed, with 985 revised to THA. The most common reasons for 1^st revision were loosening (49.3%), fracture (17.7%), and dislocation (11.0%). Of the hemiarthroplasty procedures revised to THA, 76 had a 2^nd revision. The most common reasons for 2^nd revision were fracture (27.6%), dislocation (26.3%), loosening (23.7%), and infection (18.4%). Femoral head size, DM, or constrained liner use did not alter the incidence of all-cause 2^nd revision. This did not change when solely looking at patients still alive. A 2^nd revision was more likely in patients aged <75 years.

CONCLUSION

The outcome of hemiarthroplasty performed for FNOF revised to THA is influenced by patient age, not by the articulation used.

Total Hip Arthroplasty (THA) for Femoral Neck Fractures: Comparison between Standard and Dual Mobility Implants

The purpose of this retrospective study is to compare the short-term clinical and radiological results between standard and dual mobility THA for femoral neck fractures (FNF) in older patients. The hypothesis is that the dual mobility cup (DMC) has the same outcomes but a lower dislocation rate than the standard THA. The study population included 56 patients (mean age 77.7 years, range 71–85) that underwent THA for displaced FNF. Patients were divided in two comparable groups for baseline characteristics (age, sex and comorbidities): 28 patients underwent THA with a standard cup (SC) and 28 THA with DMCs. The clinical records and radiograms were reviewed to search relevant data in their postoperative history. Two postoperative dislocations occurred in the SC group and none in the DMC group. At an average follow up of 23 months (12–40), 48 patients were available for the final evaluation. The WOMAC score for all patients averaged 6.26 (0–46) and was slightly better in the DMC group (4.94 vs. 7.58; p-value = 0.41); scores were significantly better in presence of neurological comorbidities (p-value = 0.04), in the absence of diabetes (p-value = 0.04) and in the case of psychiatric disorders (p-value = 0.02). Radiographic evaluation at one year showed signs of osteointegration in 42/48 (87.5%) acetabular components (20 DMCs, 22 SC). According to our experience, DMCs proved to be a valid option for the treatment of displaced FNF in older patients, since it allowed them to achieve short-term outcomes comparable to conventional THA, while decreasing the incidence of postoperative dislocations.

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.

The management of displaced femoral neck fractures: a narrative review

This article serves to review the existing clinical guidelines, and highlight the most recent medical and surgical recommendations, for the management of displaced femoral neck fractures (FNFs). It stresses the need for multi-disciplinary intervention to potentially improve mortality rates, limit adverse events and prevent further economic liability.Globally, the incidence of FNFs continues to rise as the general population ages and becomes more active. The annual number of FNFs is expected to exceed six million by 2050. The increased burden of FNFs exacerbates the demand on all services associated with treating these injuries.The management of FNFs may serve as an indicator of the quality of care of the geriatric population. However, despite escalating health costs, a significant 30-day and one-year mortality rate, increased rate of peri-operative adverse events and sub-optimal functional clinical outcomes, continued controversy exists over optimal patient care.Much debate exists over the type of surgery, implant selection and peri-operative clinical care and rehabilitation. FNF care models, systematized clinical pathways, formal geriatrics consultation and specialized wards within an established interdisciplinary care framework may improve outcomes, mitigate adverse events and limit unnecessary costs. Cite this article: EFORT Open Rev 2021;6:139-144. DOI: 10.1302/2058-5241.6.200036.

THA for a Fractured Femoral Neck: Comparing the Revision and Dislocation Rates of Standard-head, Large-head, Dual-mobility, and Constrained Liners

BACKGROUND

THA is a reasonable surgical option for some patients with fragility fractures of the femoral neck, but it has the risk of prosthesis dislocation. The prosthesis combination that reduces the risk of dislocation and the rate of revision surgery is not known.

QUESTIONS/PURPOSES

In patients receiving primary THA for a femoral neck fracture, does (1) the rate of all-cause revision or (2) the reason for revision and rate of revision for dislocation differ among THA with a standard head size, large head size, dual mobility (DM), or constrained liner? (3) Is there a difference in the revision risk when patients are stratified by age at the time of surgery?

METHODS

Data were analyzed for 16,692 THAs performed to treat fractures of the femoral neck reported in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from January 2008 to December 2018, as this included the first use of DM prostheses. The AOANJRR includes information on more than 98% of arthroplasty procedures performed in Australia. Most patients were female (72%) and the mean age was 74 years ± 11. There were 8582 standard-head prostheses, 5820 large-head prostheses, 1778 DM prostheses, and 512 constrained prostheses identified. The cumulative percent revision (CPR) was determined for all causes as well as CPR for dislocation. The time to the first revision was described using Kaplan-Meier estimates of survivorship, with right censoring for death or closure of the database at the time of analysis. The unadjusted CPR was estimated each year of the first 10 years for standard heads, 10 years for large heads, 8 years for constrained liners, and 7 years for DM prostheses, with 95% confidence intervals using unadjusted pointwise Greenwood estimates. The results were adjusted for age, sex, femoral fixation, and head size where appropriate and were considered by age groups < 70 and ≥ 70 years.

RESULTS

When adjusted for age, sex, femoral fixation and head size, there was no difference in the rate of all-cause revision at 7 years for any of the four groups. There was no difference in the rate of all-cause revision when patients were stratified by < 70 or ≥ 70 years of age. Dislocation was the most common reason for revision (32%). When analyzing revision for dislocation alone, large-head THA had a lower rate of revision for dislocation compared with standard head (HR 0.6 [95% CI 0.4 to 0.8]; p < 0.001) and DM prostheses had a lower rate of revision for dislocation than standard head for the first 3 months (HR 0.3 [95% CI 0.1 to 0.7]; p < 0.004) but not after this time point.

CONCLUSION

The Australian registry shows that there is no difference in the rate of all-cause revision for standard-head, large-head, DM prostheses or constrained liner THA after femoral neck fractures for all patients or for patients stratified into younger than 70 years and at least 70 years of age groups. Dislocation is the most common cause of revision. Large-head prostheses are associated with a lower revision risk for dislocation and DM prostheses have a lower rate of revision for dislocation than standard heads for the first 3 months only. Surgeons treating a femoral neck fracture with THA might consider a large head size if the diameter of the acetabulum will allow it and a DM prosthesis if a large head size is not possible. The age, life expectancy and level of function of patients with femoral neck fractures minimizes the potential long-term consequences of these prostheses. The lack of significant differences in survival between most prosthesis combinations means surgeons should continue to look for factors beyond head size and prosthesis to minimize dislocation and revision surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

What Predicts Health-Related Quality of Life for Patients With Displaced Femoral Neck Fractures Managed With Arthroplasty? A Secondary Analysis of the HEALTH Trial

BACKGROUND

Total hip arthroplasty (THA) has been argued to improve health-related quality of life (HRQoL) and function in femoral neck fracture patients compared with hemiarthroplasty (HA). The HEALTH trial showed no clinically important functional advantages of THA over HA. The current analysis explores factors associated with HRQoL and function in this population.

METHODS

Using repeated measures regression, we estimated the association between HRQoL and function [Short Form-12 (SF-12) physical component score (PCS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function score] and 23 variables.

RESULTS

THA as compared to monopolar HA, but not bipolar HA, was more likely to improve PCS scores (adjusted mean difference [AMD] 1.88 points, P = 0.02), whereas higher American Society of Anesthesiologists score (AMD -2.64, P < 0.01), preoperative use of an aid (AMD -2.66, P < 0.01), and partial weight-bearing status postoperatively (AMD -1.38, P = 0.04) demonstrated less improvement of PCS scores over time. THA improved WOMAC function scores over time compared with monopolar HA (but not bipolar HA) (AMD -2.40, P < 0.01), whereas higher American Society of Anesthesiologists classification (AMD 1.99, P = 0.01) and preoperative use of an aid (AMD 5.39, P < 0.01) were associated with lower WOMAC function scores. Preoperative treatment for depression was associated with lower functional scores (AMD 7.73, P < 0.01).

CONCLUSION

Patients receiving THA are likely to receive small and clinically unimportant improvements in health utility and function compared with those receiving monopolar HA and little improvement compared with those receiving bipolar HA. Patient-specific characteristics seem to play a larger role in predicting functional improvement among femoral neck fracture patients.

LEVEL OF EVIDENCE

Prognostic Level II.

Clinical Practice Guidelines in Action: Differences in Femoral Neck Fracture Management by Trauma and Arthroplasty Training

INTRODUCTION

The purpose of this study was to survey trauma and arthroplasty surgeons to investigate associations between subspecialty training and management of geriatric femoral neck fractures and to compare treatments with the American Academy of Orthopaedic Surgeons clinical practice guidelines.

METHODS

Five hundred fifty-six surgeons completed the online survey consisting of two sections: (1) surgeon demographics and (2) two geriatric hip fracture cases with questions regarding treatment decisions.

RESULTS

In both clinical scenarios, arthroplasty surgeons were more likely than trauma surgeons to recommend total hip arthroplasty (THA) (case 1: 96% versus 84%; case 2: 29% versus 10%; P ≤ 0.02) and spinal anesthesia (case 1: 70% versus 40%; case 2: 62% versus 38%; P < 0.01). Surgeons who have made changes based on clinical practice guidelines (n = 96; 21% of surveyed) cited more use of THA (n = 56; 58% of respondents) and cemented stems (n = 28; 29% of respondents).

CONCLUSION

Arthroplasty surgeons are more likely to recommend THA over hemiarthroplasty and have a higher expectation for spinal anesthesia for the management of geriatric femoral neck fractures.