Torsional stability of fixation methods in basicervical femoral neck fractures: a biomechanical study.

BACKGROUND: Basicervical femoral neck fracture is a rare proximal femur fracture with a high implant failure rate. Biomechanical comparisons between cephalomedullary nails (CMNs) and dynamic hip screws (DHSs) under torsion loading are lacking. This study compared the biomechanical performance of three fixations for basicervical femoral neck fractures under torsion load during early ambulation. METHODS: The biomechanical study models used three fixations: a DHS, a DHS with an anti-rotation screw, and a short CMN. Finite element analysis was used to simulate hip rotation with muscle forces related to leg swing applied to the femur. The equivalent von Mises stress (EQV) on fixation, fragment displacement, and strain energy density at the proximal cancellous bone were monitored for fixation stability. RESULTS: The EQV of the short CMN construct (304.63 MPa) was comparable to that of the titanium DHS construct (293.39 MPa) and greater than that of the titanium DHS with an anti-rotation screw construct (200.94 MPa). The proximal fragment displacement in the short CMN construct was approximately 0.13 mm, the greatest among the constructs. The risk of screw cutout for the lag screw in short CMNs was 3.1-5.8 times greater than that for DHSs and DHSs with anti-rotation screw constructs. CONCLUSIONS: Titanium DHS combined with an anti-rotation screw provided lower fragment displacement, stress, and strain energy density in the femoral head than the other fixations under torsion load. Basicervical femoral neck fracture treated with CMNs may increase the risk of lag screw cutout.

Comparison of femoral neck shortening after femoral neck system and cannulated cancellous screw fixation for displaced femoral neck fractures in young adults.

BACKGROUND: The purpose of this study was to compare the outcomes of femoral neck shortening between the femoral neck system (FNS) and the cannulated cancellous screws (CCS) for displaced femoral neck fractures in young adults PATIENTS AND METHODS: In this retrospective analysis, 225 patients aged 18-65 years with displaced femoral neck fracture were divided into two groups according to internal fixation: 135 patients in the FNS group and 90 patients in the CCS group. The length of hospital stay, duration of surgery, intraoperative blood loss, quality of reduction, extent of femoral neck shortening, incidence of femoral neck shortening, femoral neck shortening at each follow-up visit, Harris hip score (HHS), reoperation, and complications were compared between the two groups. RESULTS: The median follow-up time was 28.2 (26.0, 31.2) months in the FNS group and 30.2 (26.3, 34.7) months in the CCS group. The follow-up time, age, sex distribution, body mass index (BMI), mechanism of injury, injured side, length of hospital stay, time from injury to surgery, and fracture classification were similar between the groups. Duration of surgery was longer in the FNS group (65.0 (55.0, 87.0) min versus 55.0 (50.0, 65.0) min, P<0.001); intraoperative blood loss was greater in the FNS group (50.0 (20.0, 60.0) ml versus 20.0 (10.0, 35.0) ml, P<0.001). Femoral neck shortening was 2.4 (1.0, 4.5) mm in the FNS group versus 0.6 (0.0, 2.6) mm in the CCS group at 1 month postoperatively (P<0.001); 3.7 (1.8, 6.4) mm in the FNS group versus 1.2 (0.6, 3.8) mm in the CCS group at 3 months (P<0.001); 4.1(2.4, 7.7) mm in the FNS group versus 2.3 (1.1, 4.4) mm in the CCS group at 6 months (P<0.001); 4.2 (2.6, 7.7) mm in the FNS group versus 2.6 (1.3, 4.6) mm in the CCS group at 12 months (P<0.001); and 4.5 (2.8, 8.0) mm in the FNS group versus 2.8 (1.5, 4.8) mm in the CCS group at 18 months (P<0.001). The two groups showed no significant differences in HHS, reoperation, and reduction quality. CONCLUSION: Compared to CCS, FNS is deficient in preventing femoral neck shortening. Future research should focus on improving FNS in terms of preventing femoral neck shortening.

The case for decreased surgeon-reported complications due to surgical volume and fellowship status in the treatment of geriatric hip fracture: An analysis of the ABOS database.

INTRODUCTION: American orthopaedists are increasingly seeking fellowship sub-specialization. One proposed benefit of fellowship training is decrease in complications, however, few studies have investigated the rates of medical and surgical complications for hip fracture patients between orthopedists from different fellowship backgrounds. This study aims to investigate the effect of fellowship training and case volume on medical and surgical outcomes of patient following hip fracture surgical intervention. METHODS: 1999-2016 American Board of Orthopedic Surgery (ABOS) Part II Examination Case List data were used to assess patients treated by trauma or adult reconstruction fellowship-trained orthopedists versus all-other orthopaedists. Rates of surgeon-reported medical and surgical adverse events were compared between the three surgeon cohorts. Using binary multivariate logistic regression to control of demographic factors, independent factors were evaluated for their effect on surgical complications. RESULTS: Data from 73,427 patients were assessed. An increasing number of hip fractures are being treated by trauma fellowship trained surgeons (9.43% in 1999-2004 to 60.92% in 2011-2016). In multivariate analysis, there was no significant difference in type of fellowship, however, surgeons with increased case volume saw significantly decreased odds of complications (16-30 cases: OR = 0.91; 95% CI: 0.85-0.97; p = 0.003; 31+ cases: OR = 0.68; 95% CI: 0.61-0.76; p<0.001). Femoral neck hip fractures were associated with increased odds of surgical complications. DISCUSSION: Despite minor differences in incidence of surgical complications between different fellowship trained orthopaedists, there is no major difference in overall risk of surgical complications for hip fracture patients based on fellowship status of early orthopaedic surgeons. However, case volume does significantly decrease the risk of surgical complications among these patients and may stand as a proxy for fellowship training. Fellows required to take hip fracture call as part of their training regardless of fellowship status exhibited decreased complication risk for hip fracture patients, thus highlighting the importance of additional training.

The oblique triangle configuration of three parallel screws for femoral neck fracture fixation using computer-aided design modules.

Closed reduction and internal fixation with three cannulated compression screws is a common method for treating femoral neck fractures in young and middle-aged patients. Protocols including the inverted triangle configuration and dispersion of the screws still needed further supports. The purpose of this study was to explore a novel oblique triangle configuration (OTC) of three screws in fixing femoral neck fractures based on the morphology of the femoral neck isthmus (FNI). The computer-aided design modules were used to explore the ideal spatial configuration with largest triangle by three parallel screws. A univariate evaluation model was established based on the oval-like cross-section of the FNI. When the three screws were positioned by the OTC, Inverted Equilateral Triangle Configuration (IETC), and the Maximum Area Inverted Isosceles Triangle Configuration (MA-IITC) respectively, the proportion of area and circumference in the cross-section of FNI and the changing trend of proportion were compared under various torsion angles, eccentricity, and cross-sectional area of FNI. The area and circumference ratios of the parallel screws using the OTC method were significantly higher than in the IETC and MA-IITC groups. In the univariate evaluation model, the OTC area ratio and circumference ratio remained stable under the different femoral neck torsion angles, FNI cross-sectional area, and eccentricity. The OTC method provided an ideal spatial configuration for the FNA fixation with the largest area using three parallel screws. The position of the posterior screw was also away from the metaphyseal artery, potentially reducing the possibility of vascular injury and screw penetrating.

Analysis on risk factors for neck shortening after internal fixation for Pauwels II femoral neck fracture in young patients.

BACKGROUND: Femoral neck shortening can occur in young patients receiving internal fixation for Pauwels type II femoral neck fracture. The risk factors for neck shortening, which can affect hip function, are not clear. This study aimed to retrospectively identify risk factors for neck shortening after internal fixation with parallel partially threaded cannulated cancellous screws (FPTCS) for Pauwels type II femoral neck fracture in relatively young patients. METHODS: Clinical data from 122 cases with Pauwels type II femoral neck fracture from February 2014 to February 2019 were reviewed and analyzed, and causes of neck shortening were statistically analyzed. And the Chi-squared test or Fisher's exact test was used to compare indicators. Multivariate analysis was conducted with non-conditional logistic regression analysis. RESULTS: Statistically significant differences were found in age, sex, BMD, BMI, fracture type, posterior medial cortex comminution, and reduction quality between patients with femoral neck shortening and those without femoral neck shortening. Logistic regression analysis showed that fracture type, posterior medial cortex comminution, and reduction quality were the main risk factors for neck shortening. CONCLUSION: Fracture type, posterior medial cortex comminution, and reduction quality can be used as important reference indexes to predict the possibility of neck shortening after internal fixation with FPTCS for Pauwels type II femoral neck fracture in young patients. BMD and BMI may be also risk factors.

The Application of Fascia Iliaca Compartment Block for Acute Pain Control of Hip Fracture and Surgery.

PURPOSE OF REVIEW: Over 300,000 patients are hospitalized annually following hip fractures in the USA. Many patients experienced inadequate analgesia. We will review the perioperative effects of the fascia iliaca compartment block (FICB) in hip fracture patients. RECENT FINDINGS: FICB by injecting local anesthetics beneath the fascia iliaca results in significant pain relief in hip fractures. Neuropathies and vascular injuries are almost unlikely. Single-shot FICB is faster to place, yet providing about 8 h of analgesia when bupivacaine is used. Continuous FICB provides prolonged titratable analgesia, improved patient satisfaction, and leads to faster hospital discharge. FICB reduces opioid consumption, decreases morbidity and mortality, reduces hospital stay, reduces delirium, and improves satisfaction. FICB should form part of a multimodal analgesic regime, in the context of a multidisciplinary approach to the management of hip fracture patients. More clinical investigations are needed to validate the long-term outcome benefits of FICB in hip fracture patients.

Integrating real-world data and modeling to project changes in femoral neck bone mineral density and fracture risk in premenopausal women.

Decline of bone mineral density (BMD) during menopause is related to increased risk of fractures in postmenopausal women, however, this relationship in premenopausal women has not been established. To quantify this relationship, real-world data (RWD) from the National Health and Nutrition Examination Survey (NHANES), and longitudinal data from the elagolix phase III clinical trials were modeled across a wide age range, and covariates were evaluated. The natural changes in femoral neck BMD (FN-BMD) were well-described by a bi-exponential relationship with first-order BMD formation (k1 ) and resorption (k2 ) rate constants. Body mass index (BMI) and race (i.e., Black) were significant predictors indicating that patients with high BMI or Black race experience a relatively lower BMD loss. Simulations suggest that untreated premenopausal women with uterine fibroids (UFs) from elagolix phase III clinical trials (median age 43 years [minimum 25-maximum 53]) lose 0.6% FN-BMD each year up to menopausal age. For clinical relevance, the epidemiological FRAX model was informed by the simulation results to predict the 10-year risk of major osteoporotic fracture (MOF). Premenopausal women with UFs, who received placebo only in the elagolix phase III trials, have a projected FN-BMD of 0.975 g/cm2 at menopause, associated with a 10-year risk of MOF of 2.3%. Integration of modeling, RWD, and clinical trials data provides a quantitative framework for projecting long-term postmenopausal risk of fractures, based on natural history of BMD changes in premenopausal women. This framework enables quantitative evaluation of the future risk of MOF for women receiving medical therapies (i.e., GnRH modulators) that adversely affect BMD.

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.

The local concentration of Ca2+ correlates with BMP7 expression and osseointegration in patients with total hip arthroplasty.

BACKGROUND: A successful osseointegration of total hip arthroplasty (THA) relies on the interplay of implant surface and bone marrow microenvironment. This study was undertaken to investigate the impact of perioperative biochemical molecules (Ca2+, Mg2+, Zn2+, VD, PTH) on the bone marrow osteogenetic factors (BMP2, BMP7, Stro-1+ cells) in the metaphyseal region of the femoral head, and further on the bone mineral density (BMD) of Gruen R3. METHODS: Bone marrow aspirates were obtained from the discarded metaphysis region of the femoral head in 51 patients with THA. Flow cytometry was used to measure the Stro-1+ expressing cells. ELISA was used to measure the concentrations of bone morphologic proteins (BMP2 and BMP7) and the content of TRACP5b in serum. TRAP staining was used to detect the osteoclast activity in the hip joint. The perioperative concentrations of the biochemical molecules above were measured by radioimmunoassay. The BMD of Gruen zone R3 was examined at 6 months after THA, using dual-energy X-ray absorptiometry (DEXA). RESULTS: Our data demonstrated that the concentration of Ca2+ was positively correlated with BMP7 expression, and with the postoperative BMD of Gruen zone R3. However, the concentration of Mg2+ had little impact on the R3 BMD, although it was negatively correlated with the expression of BMP7. Osteoclast activity in hip joint tissue of patients with femoral neck fractures was increased. Compared with the patients before THA, the levels of TRACP5b in serum of patients after THA were decreased. The data also suggested that the other biochemical molecules, such as Zn2+, VD, and PTH, were not significantly correlated with any bone marrow osteogenetic factors (BMP2, BMP7, Stro-1+ cells). The postoperative R3 BMD of patients of different gender and age had no significant difference. CONCLUSIONS: These results indicate the local concentration of Ca2+ may be an indicator for the prognosis of THA patients.

Age related changes in the bone microstructure in patients with femoral neck fractures.

BACKGROUND: The risk of femoral neck fracture progressively increases with age. However, the reasons behind this consistent increase in the fracture risk can't be completely justified by the decrease in the bone mineral density. The objective of this study was to analyze the correlation between various bone structural features and age. STUDY DESIGN & METHODS: A total of 29 consecutive patients who suffered an intracapsular hip fracture and underwent joint replacement surgery between May 2012 and March 2013 were included in this study. A 2 cm × 1 cm Ø cylindrical trabecular bone sample was collected from the femoral heads and preserved in formaldehyde. Bone mineral density (BMD), microarchitecture, organic content and crystallography were analyzed using a Dual-energy X-ray absorptiometry scan, micro-CT scan, and high resolution magic-angle-spinning-nuclear magnetic resonance (MAS-NMR), respectively. Statistical correlations were made using Spearman´s or Pearson´s correlation tests depending on the distribution of the continuous variables. RESULTS: The mean patient age was 79.83 ± 9.31 years. A moderate negative correlation was observed between age and the hydrogen content in bone (1H), which is an indirect estimate to quantify the organic matrix (r = -0.512, p = 0.005). No correlations were observed between BMD, trabecular number, trabecular thickness, phosphorous content, apatite crystal size, and age (r = 0.06, p = 0.755; r = -0.008, p = 0.967; r = -0.046, p = 0.812; r = -0.152, p = 0.430, respectively). A weak positive correlation was observed between Charlson´s comorbidity index (CCI) and c-axis of the hydroxiapatite (HA) crystals (r = -0.400, p = 0.035). CONCLUSION: The femoral head relative protein content progressively decreases with age. BMD was not correlated with other structural bone parameters and age. Patients with higher comorbidity scores had larger HA crystals. The present results suggest that the progressive increase in the hip fracture risk in elderly patients could be partially explained by the lower bone protein content in this age group.

Gotfried positive reduction promotes the repair of femoral neck fracture potentially via enhancing osteogenesis and angiogenesis.

The aim of this study was to investigate the effect of Gotfried positive reduction (GPR) on repair of femoral neck fracture in rabbits and its underlying mechanisms. Male New Zealand white rabbits were employed to establish the model of femoral neck fracture. All the rabbits were randomly divided into four groups: control, open accurate reduction (OR), closed Gotfried negative support reduction (CR-N) and closed Gotfried positive support reduction (CR-P). At the 8th and 12th week after surgery, the anteroposterior and lateral radiographs of their hip joints were taken by X-ray, and local hemodynamics of their hip joints was detected by ultrasound. Histological examination was evaluated by HE staining and bone biological strength test was measured by testing machine, which was performed to study the repair of femoral neck fracture. Osteogenesis and angiogenesis-related proteins were measured by western blot in bone tissues and synovial tissues. The results revealed that the fracture healing intensity and blood supply in CR-P were better than those in CR-N and much more excellent than those in OR. In addition, the content of bone morphogenetic protein2 (BMP2), platelet derived growth factor (PDGF) and ocsteocalcin was higher in CR-P group than in CR-N, while lower in CR-P than OR. Furthermore, the expression of BMP2, COL-2 and angiopoietin (ANGPT) was upregulated in CR-P compared to CR-N and OR. Taken together, our results indicated that GPR was able to promote the repair of femoral neck fracture via enhancing osteogenesis and angiogenesis, which is valuable to us and shows good application prospect in bone tissue repair.

Association between osteoporotic femoral neck fractures and DXA-derived 3D measurements at lumbar spine: a case-control study.

A case-control study assessing the association of DXA-derived 3D measurements at lumbar spine with osteoporotic hip fractures was performed. Stronger association was found between transcervical hip fractures and integral (AUC = 0.726), and cortical (AUC = 0.696) measurements at the lumbar spine compared with measurements at the trabecular bone (AUC = 0.617); although femur areal bone mineral density (aBMD) remains the referent measurement for hip fracture risk evaluation (AUC = 0.838). PURPOSE: The aim of the present study was to evaluate the association between DXA-derived 3D measurements at lumbar spine and osteoporotic hip fractures. METHODS: We analyzed a case-control database composed by 61 women with transcervical hip fractures and 61 age-matched women without any type of fracture. DXA scans at lumbar spine were acquired, and areal bone mineral density (aBMD) was measured. Integral, trabecular and cortical volumetric BMD (vBMD), cortical thickness, and cortical surface BMD (sBMD) at different regions of interest were assessed using a DXA-based 3D modeling software. Descriptive statistics, tests of difference, odds ratio (OR), and area under the receiver operating curve (AUC) were used to compare hip fracture and control groups. RESULTS: Integral vBMD, cortical vBMD, cortical sBMD, and cortical thickness were the DXA-derived 3D measurements at lumbar spine that showed the stronger association with transcervical hip fractures, with AUCs in the range of 0.685-0.726, against 0.670 for aBMD. The highest AUC (0.726) and OR (2.610) at the lumbar spine were found for integral vBMD at the posterior vertebral elements. Significantly, lower AUC (0.617) and OR (1.607) were found for trabecular vBMD at the vertebral body. Overall, total femur aBMD remains the DXA-derived measurement showing the highest AUC (0.838) and OR (6.240). CONCLUSION: This study showed the association of DXA-derived measurements at lumbar spine with transcervical hip fractures. A strong association between vBMD at the posterior vertebral elements and transcervical hip fractures was observed, probably because of global deterioration of the cortical bone. Further studies should be carried out to investigate on the relative risk of transcervical fracture in patients with long-term cortical structural deterioration.

Direct anterior versus posterolateral approach for bipolar hip hemiarthroplasty in femoral neck fractures: a prospective randomised study.

INTRODUCTION: Femoral neck fractures are a major problem in orthopaedic practice, having a huge impact on society, and involving a large number of elderly patients for whom early recovery is paramount. Thus, the aim of this study was to compare 2 surgical approaches, direct anterior (DA group) versus posterolateral (PL group), used for bipolar hip hemiarthroplasty (BHA) with femoral neck fractures in order to assess pain recovery after surgery. Our hypothesis was that early pain recovery would be faster in the DA group. METHODS: 100 patients were randomised to surgery using either a DA group or PL group approach, and were then followed up for 6 months. Surgical time, intra- and postoperative complications were recorded for each patient. The main outcome, pain, was recorded using an NRS scale at 3 days, 1, 3 and 6 months after surgery. At the same time, patient status was evaluated using Activities of Daily Living and Cumulated Ambulation Score scales. RESULTS: Surgical time was longer in the DA group (p < 0.0001). Pain perception at 3 days and at 1 month after surgery was significantly lower in DA group patients (p < 0.0001). The results of the other scales were comparable in the 2 groups (at 3 days, 1 and 3 months after surgery). DISCUSSION: The DA approach offers a significant advantage in terms of pain perception up to 1 month after the operation. Early recovery in terms of pain perception is an important finding. Future studies should explore whether this early pain reduction could translate into a faster rehabilitation programme for an earlier recovery of full function.Clinical trial registration: Protocol 423/CE; Study n. CE 41/15.

Adverse plasma fatty acid composition in patients with femoral neck fracture1.

Our study aimed to examine the status of plasma fatty acids (FAs), inflammatory markers, and lipid peroxidation in patients with femoral neck fractures. The study included 20 patients (64-86 years) with femoral neck fractures indicated for surgery and a control group of 17 elderly subjects without fractures or serious chronic diseases. Plasma was obtained during the first 12 h postfracture and presurgery and 7 days postop. Compared to the control, patients had significantly higher saturated FA (SFA) and monounsaturated FA as well as increased TNF-α and IL-6. Opposite to that, levels of individual and total n-6 polyunsaturated FA (PUFA), individual and total n-3 PUFA, n-6/n-3 ratio, and levels of thiobarbituric acid reactive substances (TBARS) were markedly lower in the patient than in the controls. On the seventh day after the surgery, we showed a further rise in the SFA, oleic acid, and TNF-α and reductions of n-6 PUFA and IL-6. Taken together, our results suggest that altered FA status, especially reduced PUFA, may influence hip fracture repair and even contribute to femoral fracture susceptibility in the elderly. A potential benefit from nutritional intervention with PUFA in prevention and (or) fracture healing should be considered.

Topical cutaneous application of carbon dioxide via a hydrogel for improved fracture repair: results of phase I clinical safety trial.

BACKGROUND: Clinicians have very limited options to improve fracture repair. Therefore, it is critical to develop a new clinically available therapeutic option to assist fracture repair biologically. We previously reported that the topical cutaneous application of carbon dioxide (CO2) via a CO2 absorption-enhancing hydrogel accelerates fracture repair in rats by increasing blood flow and angiogenesis and promoting endochondral ossification. The aim of this study was to assess the safety and efficacy of CO2 therapy in patients with fractures. METHODS: Patients with fractures of the femur and tibia were prospectively enrolled into this study with ethical approval and informed consent. The CO2 absorption-enhancing hydrogel was applied to the fractured lower limbs of patients, and then 100% CO2 was administered daily into a sealed space for 20 min over 4 weeks postoperatively. Safety was assessed based on vital signs, blood parameters, adverse events, and arterial and expired gas analyses. As the efficacy outcome, blood flow at the level of the fracture site and at a site 5 cm from the fracture in the affected limb was measured using a laser Doppler blood flow meter. RESULTS: Nineteen patients were subjected to complete analysis. No adverse events were observed. Arterial and expired gas analyses revealed no adverse systemic effects including hypercapnia. The mean ratio of blood flow 20 min after CO2 therapy compared with the pre-treatment level increased by approximately 2-fold in a time-dependent manner. CONCLUSIONS: The findings of the present study revealed that CO2 therapy is safe to apply to human patients and that it can enhance blood flow in the fractured limbs. TRIAL REGISTRATION: This study has been registered in the UMIN Clinical Trials Registry (Registration number: UMIN000013641, Date of registration: July 1, 2014).

Biomechanics of Osteoporotic Fracture Fixation.

PURPOSE OF REVIEW: Fractures of osteoporotic bone in elderly individuals need special attention. This manuscript reviews the current strategies to provide sufficient fracture fixation stability with a particular focus on fractures that frequently occur in elderly individuals with osteoporosis and require full load-bearing capacity, i.e., pelvis, hip, ankle, and peri-implant fractures. RECENT FINDINGS: Elderly individuals benefit immensely from immediate mobilization after fracture and thus require stable fracture fixation that allows immediate post-operative weight-bearing. However, osteoporotic bone has decreased holding capacity for metallic implants and is thus associated with a considerable fracture fixation failure rate both short term and long term. Modern implant technologies with dedicated modifications provide sufficient mechanical stability to allow immediate weight-bearing for elderly individuals. Depending on fracture location and fracture severity, various options are available to reinforce or augment standard fracture fixation systems. Correct application of the basic principles of fracture fixation and the use of modern implant technologies enables mechanically stable fracture fixation that allows early weight-bearing and results in timely fracture healing even in patients with osteoporosis.

A quantitative biomechanical study of positive buttress techniques for femoral neck fractures: a finite element analysis.

BACKGROUND: Refractory femoral neck fractures cannot be anatomically reduced by closed traction reduction which may affect fracture healing. We evaluated the biomechanical effects of positive, negative, and anatomic reduction of various degrees of displacement in Pauwels I femoral neck fractures by a finite element analysis. METHODS: Five reduction models of Pauwels type I femoral neck fracture were established using the Mimics 17.0 (Materialize, Leuven, Belgia) and Hypermesh 12.0 (Altair Engineering, Troy, MI, USA). According to the degree of fracture displacement, there were three models of positive support, an anatomic reduction model, and a negative 2 mm reduction model. Finite element analysis was conducted using the ABAQUS 6.9 software (Simulia, Suresnes, France). The von Mises stress distribution and the stress peak of internal fixation in different models, the displacement between fracture blocks, and the principal strain of the femoral neck cancellous bone model were recorded under the axial stress of 2100 N. RESULTS: The peak von Mises stress on screw of each model was located at the thread of the screw tip. The peak von Mises stress was the lowest at the tip of the anatomic reduction model screw (261.2 MPa). In the positive 4 mm model, the von Mises stress peak was the highest (916.1 MPa). The anatomic reduction model showed the minimum displacement (0.388 mm) between fracture blocks. The maximum displacement was noted in the positive 4 mm model (0.838 mm). The displacement in the positive 3 mm model (0.721 mm) was smaller than that in the negative 2 mm model (0.786 mm). Among the five models, the strain area of the femoral neck cancellous bone was mainly concentrated around the screw hole, and the area around the screw hole could be easily cut. CONCLUSIONS: Compared with negative buttress for femoral neck fracture, positive buttress can provide better biomechanical stability. In Pauwel type I fracture of femoral neck, the range of positive buttress should be controlled below 3 mm as far as possible.

Hidden blood loss after hip hemiarthroplasty using the superPATH approach: A retrospective study.

OBJECTIVE: The purpose of this study was to compare perioperative hidden blood loss after hip hemiarthroplasty via the SuperPATH approach and the conventional posterior approach (the Moore approach). PATIENTS AND METHODS: From January 2015 to January 2017, 130 patients (80.7 ±â€¯6.0 years) with displaced femoral neck fracture (Garden type III or IV) undergoing hip hemiarthroplasty were included in this study. As a non-randomisation study, Fifty-two patients (SuperPATH group) were operated using the SuperPATH approach, and 78 patients (Moore group) were operated with the conventional posterior approach (Moore approach). The demographic and relevant clinical information of the patients were collected. According to the combination formulas of Nadler, Gross and Sehat, the hidden blood loss (HBL) of each patient was calculated. Student's t-test for independent samples was used to compare the normally distributed variables and the Mann-Whitney U test was used to compare variables not following a normal distribution. RESULTS: The visible blood loss (VBL) in the SuperPATH group was 123.7 ±â€¯47.5 ml, the hidden blood loss (HBL) was 1084.1 ±â€¯816.8 ml and the HBL% was 82.7 ±â€¯16.5%. In the Moore group, the VBL was 303.6 ±â€¯139.6 ml, the HBL was 700.2 ±â€¯563.8 ml and the HBL% was 61.5 ±â€¯23.8%. The patients in the SuperPATH group had more HBL and HBL% (P < 0.05). However, no significant difference was observed of total blood loss (TBL) between the two groups (P = 0.125). CONCLUSIONS: HBL should not be ignored in patients who underwent hip hemiarthroplasty for displaced femoral neck fractures, as it is a significant portion of TBL. Compared with the conventional approach, the SuperPATH approach had a greater amount of HBL. A better understanding of HBL after hip hemiarthroplasty may help surgeons improve clinical assessment and ensure patient safety.

Treatment of the displaced intracapsular fracture for the 'fitter' elderly patients: A randomised trial of total hip arthroplasty versus hemiarthroplasty for 105 patients.

Controversy exists for the optimum method of surgical treatment for the 'fitter' elderly patient with a displaced intracapsular fracture. 105 patients were randomised to treatment with either a cemented polished tapered stem hemiarthroplasty or a cemented total hip arthroplasty (THR) with a cemented acetabular cup. All patients were followed up for a minimum of one year using a blinded assessment of functional outcome. Those patients treated with a THR had a tendency to a longer hospital stay and increased medical (12 versus 62) and surgical complications (4 versus 2) in comparison to those treated by hemiarthroplasty. Mean operative times (842 versus 52 min) and operative blood loss (335mls versus 244mls) were increased for THR. Final outcome measures of residual pain and regain of function were similar for both methods of treatment. We recommend that caution should be exercised regarding the increased promotion of THR for intracapsular hip fractures until further studies are completed.

Total Hip Arthroplasty or Hemiarthroplasty for Hip Fracture.

BACKGROUND: Globally, hip fractures are among the top 10 causes of disability in adults. For displaced femoral neck fractures, there remains uncertainty regarding the effect of a total hip arthroplasty as compared with hemiarthroplasty. METHODS: We randomly assigned 1495 patients who were 50 years of age or older and had a displaced femoral neck fracture to undergo either total hip arthroplasty or hemiarthroplasty. All enrolled patients had been able to ambulate without the assistance of another person before the fracture occurred. The trial was conducted in 80 centers in 10 countries. The primary end point was a secondary hip procedure within 24 months of follow-up. Secondary end points included death, serious adverse events, hip-related complications, health-related quality of life, function, and overall health end points. RESULTS: The primary end point occurred in 57 of 718 patients (7.9%) who were randomly assigned to total hip arthroplasty and 60 of 723 patients (8.3%) who were randomly assigned to hemiarthroplasty (hazard ratio, 0.95; 95% confidence interval [CI], 0.64 to 1.40; P = 0.79). Hip instability or dislocation occurred in 34 patients (4.7%) assigned to total hip arthroplasty and 17 patients (2.4%) assigned to hemiarthroplasty (hazard ratio, 2.00; 99% CI, 0.97 to 4.09). Function, as measured with the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score, pain score, stiffness score, and function score, modestly favored total hip arthroplasty over hemiarthroplasty. Mortality was similar in the two treatment groups (14.3% among the patients assigned to total hip arthroplasty and 13.1% among those assigned to hemiarthroplasty, P = 0.48). Serious adverse events occurred in 300 patients (41.8%) assigned to total hip arthroplasty and in 265 patients (36.7%) assigned to hemiarthroplasty. CONCLUSIONS: Among independently ambulating patients with displaced femoral neck fractures, the incidence of secondary procedures did not differ significantly between patients who were randomly assigned to undergo total hip arthroplasty and those who were assigned to undergo hemiarthroplasty, and total hip arthroplasty provided a clinically unimportant improvement over hemiarthroplasty in function and quality of life over 24 months. (Funded by the Canadian Institutes of Health Research and others; ClinicalTrials.gov number, NCT00556842.).