Outcome of Hemiarthroplasty and Total Hip Replacement for Active Elderly Patients with Displaced Femoral Neck Fractures: A Meta-Analysis of 8 Randomized Clinical Trials

Background

Displaced fracture of the femoral neck has been a common clinical problem, especially in aged patients. However, the optimal treatment choice remains controversial. The purpose of this study is to conduct a systematic review of randomized clinical trials assessing the results of hemiarthroplasty and total hip replacement in patients undergoing either alternative using meta-analysis.

Methods

A literature search for randomized clinical trials was conducted through Medline, Embase and Cochrane library between 1969 and 2013 with no restrictions. Additional relevant articles were referred as source of information by way of manual searches on major orthopedic journals. Upon the search, two authors independently evaluated study quality and relevant data was extracted.

Results

A total of 8 studies with 983 patients were included in this meta-analysis. After pooling the available data, a significant dominance of Harris hip score was found for total hip replacement compared with hemiarthroplasty (SMD: −7.11, 95%:−10.70,−3.53) one year postoperatively and the advantage kept over (SMD: −6.91, 95%:−12.98, −0.85) two years after surgery. A trend toward a higher dislocation rate was found in total hip replacement group (RR: 0.46, 95%: 0.21, 1.02), of which the difference was considered insignificant. The risk of revision in group hemiarthroplasty appeared to be more than two folds higher than that after total hip replacement (RR: 4.14, 95%CI: 2.09, 8.19).

Conclusion

Even though there is a higher rate of dislocation after total hip replacement, this disadvantage could be accounted for, on the basis of a better functional score and the lower revision rate. However, from the results, it stands to reason that total hip replacement should be strongly suggested in elderly active patients with femoral neck fracture.     

Cemented versus Uncemented Hemiarthroplasty for Femoral Neck Fractures in Elderly Patients: A Meta-Analysis

Objective

Controversy still exists regarding using cemented or uncemented hemiarthroplasty for femoral neck fractures in elderly patients. The aim of this study is to compare the effectiveness and safety of the two surgical techniques in femoral neck fracture patients over 70 years old.

Methods

We searched PUBMED, EMBASE, Cochrane Library, CNKI and VIP Database from inception to December 2012 for relevant randomized controlled trials (RCTs). Outcomes of interest include postoperative hip function, residue pain, complication rates, mortality, reoperation rate, operation time and intraoperative blood loss. Odds ratios (OR) and weighted mean differences (WMD) from each trial were pooled using random-effects model or fixed-effects model given on the heterogeneity of the included studies.

Results

7 RCTs involving 1,125 patients (1,125 hips) were eligible for meta-analysis. Our results demonstrate that cemented hemiarthroplasty is associated with better postoperative hip function (OR = 0.48, 95% CI, 0.31–0.76; P = 0.002), lower residual pain (OR = 0.43, 95%CI, 0.29–0.64; P<0.0001), less implant-related complications (OR = 0.15, 95%CI, 0.09–0.26; P<0.00001) and longer operation time (WMD = 7.43 min, 95% CI, 5.37–9.49 min; P<0.00001). No significant difference was observed between the two groups in mortality, cardiovascular and cerebrovascular complications, local complications, general complications, reoperation rate and intraoperative blood loss.

Conclusions

Compared with uncemented hemiarthroplasty, the existing evidence indicates that cemented hemiarthroplasty can achieve better hip function, lower residual pain and less implant-related complications with no increased risk of mortality, cardiovascular and cerebrovascular complications, general complications, local complications and reoperation rate in treating elderly patients with femoral neck fractures.     

Total Hip Replacement for the Treatment of End Stage Arthritis of the Hip: A Systematic Review and Meta-Analysis

Background

Evolvements in the design, fixation methods, size, and bearing surface of implants for total hip replacement (THR) have led to a variety of options for healthcare professionals to consider. The need to determine the most optimal combinations of THR implant is warranted. This systematic review evaluated the clinical effectiveness of different types of THR used for the treatment of end stage arthritis of the hip.

Methods

A comprehensive literature search was undertaken in major health databases. Randomised controlled trials (RCTs) and systematic reviews published from 2008 onwards comparing different types of primary THR in patients with end stage arthritis of the hip were included.

Results

Fourteen RCTs and five systematic reviews were included. Patients experienced significant post-THR improvements in Harris Hip scores, but this did not differ between impact types. There was a reduced risk of implant dislocation after receiving a larger femoral head size (36 mm vs. 28 mm; RR = 0.17, 95% CI: 0.04, 0.78) or cemented cup (vs. cementless cup; pooled odds ratio: 0.34, 95% CI: 0.13, 0.89). Recipients of cross-linked vs. conventional polyethylene cup liners experienced reduced femoral head penetration and revision. There was no impact of femoral stem fixation and cup shell design on implant survival rates. Evidence on mortality and complications (aseptic loosening, femoral fracture) was inconclusive.

Conclusions

The majority of evidence was inconclusive due to poor reporting, missing data, or uncertainty in treatment estimates. The findings warrant cautious interpretation given the risk of bias (blinding, attrition), methodological limitations (small sample size, low event counts, short follow-up), and poor reporting. Long-term pragmatic RCTs are needed to allow for more definitive conclusions. Authors are encouraged to specify the minimal clinically important difference and power calculation for their primary outcome(s) as well CONSORT, PRISMA and STROBE guidelines to ensure better reporting and more reliable production and assessment of evidence.     

全髋关节置换术与双极人工股骨头置换术治疗老年股骨颈骨折的临床疗效

目的：探讨全髋关节置换术（THA）与双极人工股骨头置换术（BHA）治疗老年股骨颈骨折的临床疗效。方法：选择2013 年7 月-2015 年3 月我院收治的老年股骨颈骨折患者90 例,根据手术方法不同将患者分为全髋关节置换组（THA 组）和双极人工股 骨头置换组（BHA 组）,每组45 例。观察并比较两组患者的手术时间、术中出血量、住院时间、术后并发症的发生率及手术效果。结 果：两组患者的手术时间、术中出血量及住院时间比较,差异无统计学意义（P>0.05）;THA 组并发症的发生率明显低于BHA 组, 差异具有统计学意义（P<0.05）;术后1 年,两组手术优良率比较,差异无统计学意义（P>0.05）;术后两年及三年,THA 组手术优良 率明显高于BHA 组,差异具有统计学意义（P<0.05）。结论：THA和BHA 治疗老年股骨颈骨折均具有良好的临床疗效,但THA具 有更好的远期疗效,而且术后并发症的发生率较低。     

Bone related health status in adolescent cyclists

Purpose

To describe bone status and analyse bone mass in adolescent cyclists.

Methods

Male road cyclists (n = 22) who had been training for a minimum of 2 years and a maximum of 7 years with a volume of 10 h/w, were compared to age-matched controls (n = 22) involved in recreational sports activities. Subjects were divided in 2 groups based on age: adolescents under 17 yrs (cyclists, n = 11; controls, n = 13) and over 17 yrs (cyclists, n = 11; controls, n = 9). Peak oxygen uptake (VO₂max) was measured on a cycloergometer. Whole body, lumbar spine, and hip bone mineral content (BMC), density (BMD) and bone area were assessed using dual x-ray absorptiometry (DXA). Volumetric BMD (vBMD) and bone mineral apparent density (BMAD) were also estimated.

Results

The BMC of cyclists was lower for the whole body, pelvis, femoral neck and legs; BMD for the pelvis, hip, legs and whole body and legs bone area was lower but higher in the hip area (all, P≤0.05) after adjusting by lean mass and height. The BMC of young cyclists was 10% lower in the leg and 8% higher in the hip area than young controls (P≤0.05). The BMC of cyclists over 17 yrs was 26.5%, 15.8% and 14.4% lower BMC at the pelvis, femoral neck and legs respectively while the BMD was 8.9% to 24.5% lower for the whole body, pelvis, total hip, trochanter, intertrochanter, femoral neck and legs and 17.1% lower the vBMD at the femoral neck (all P≤0.05). Grouped by age interaction was found in both pelvis and hip BMC and BMD and in femoral neck vBMD (all P≤0.05).

Conclusion

Cycling performed throughout adolescence may negatively affect bone health, then compromising the acquisition of peak bone mass.     

Structural changes of hip osteoarthritis using magnetic resonance imaging

Introduction

Few data are available concerning structural changes at the hip observed by magnetic resonance imaging (MRI) in people with or without hip osteoarthritis (OA). The aim of this study was to compare cartilage volume and the presence of cartilage defects and bone marrow lesions (BMLs) in participants with and without diagnosed hip OA.

Methods

Femoral head cartilage volume was measured by MRI for 141 community-based persons with no diagnosed hip OA, and 19 with diagnosed hip OA. Cartilage defects and BMLs were regionally scored at the femoral head and acetabulum.

Results

Compared with those without diagnosed hip OA, people with diagnosed hip OA had less femoral head cartilage volume (1763 mm³ versus 3343 mm³; p <0.001) and more prevalent cartilage defects and BMLs (all p ≤0.05) at all sites other than the central inferomedial region of the femoral head. In those with no diagnosed hip OA, cartilage defects in the anterior and central superolateral region of the femoral head were associated with reduced femoral head cartilage volume (all p ≤0.02). Central superolateral BMLs at all sites were associated with reduced femoral head cartilage volume (all p ≤0.003), with a similar trend occurring when BMLs were located in the anterior region of the hip (all p ≤0.08).

Conclusions

Compared with community-based adults with no diagnosed hip OA, people with diagnosed hip OA have less femoral head cartilage volume and a higher prevalence of cartilage defects and BMLs. For people with no diagnosed hip OA, femoral head cartilage volume was reduced where cartilage defects and/or BMLs were present in the anterior and central superolateral regions of the hip joint. Cartilage defects and BMLs present in the anterior and central superolateral regions may represent early structural damage in the pathogenesis of hip OA.     

Radiotherapy induced hip joint avascular necrosis—Two cases report

Background

Avascular necrosis (AVN) refers to the death of osteocytes and osteoblasts. Sites such as the femoral head, the head of the humerus and the mandibula with restricted access to local blood supply are particularly vulnerable to osteonecrosis.A combination of several factors is responsible for ischaemia and is associated with AVN: corticosteroids, alcohol abuse, Cushing''s syndrome, SLE, systemic vasculitis, RA, scleroderma, haemoglobinopathies, radiotherapy. Management is based on proper diagnosis and treatment – conservative, pharmacological or surgical.Radiotherapy has become an integral part of the therapeutic programme of cancer patients. However, early and late after-effects of irradiation still constitute a significant issue in clinical practice.

Aim

The aim of this report is to present two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic irradiation and draw physicians’ attention to that clinical problem which continues to be underestimated.

Materials and methods

This report documents two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic radiation.

Results

Avascular necrosis (AVN) constitutes a severe and challenging long-term complication in radiation oncology.

Conclusion

It is necessary to take into account bone structures among organ at risk (OAR) involved in irradiation fields. The detailed analysis of the dose distribution and the use of collimators allow to decrease the total dose to OAR.An adequate management, early diagnosis and prompt, proper treatment may protect patients from long-term morbidities.     

Deformation of the Durom Acetabular Component and Its Impact on Tribology in a Cadaveric Model—A Simulator Study

Background

Recent studies have shown that the acetabular component frequently becomes deformed during press-fit insertion. The aim of this study was to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the Durom large head metal-on-metal (MOM) total hips in simulators.

Methods

Six Durom cups impacted into reamed acetabula of fresh cadavers were used as the experimental group and another 6 size-paired intact Durom cups constituted the control group. All 12 Durom MOM total hips were put through a 3 million cycle (MC) wear test in simulators.

Results

The 6 cups in the experimental group were all deformed, with a mean deformation of 41.78±8.86 µm. The average volumetric wear rate in the experimental group and in the control group in the first million cycle was 6.65±0.29 mm³/MC and 0.89±0.04 mm³/MC (t = 48.43, p = 0.000). The ion levels of Cr and Co in the experimental group were also higher than those in the control group before 2.0 MC. However there was no difference in the ion levels between 2.0 and 3.0 MC.

Conclusions

This finding implies that the non-modular acetabular component of Durom total hip prosthesis is likely to become deformed during press-fit insertion, and that the deformation will result in increased volumetric wear and increased ion release.

Clinical Relevance

This study was determined to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the prosthesis. Deformation of the cup after implantation increases the wear of MOM bearings and the resulting ion levels. The clinical use of the Durom large head prosthesis should be with great care.     

The Mechanical Benefit of Medial Support Screws in Locking Plating of Proximal Humerus Fractures

Background

The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures.

Methods

Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed.

Results

Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001). When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P≤0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture.

Conclusions

Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure.     

Meta-Analysis of a Complex Network of Non-Pharmacological Interventions: The Example of Femoral Neck Fracture

Background

Surgical interventions raise specific methodological issues in network meta-analysis (NMA). They are usually multi-component interventions resulting in complex networks of randomized controlled trials (RCTs), with multiple groups and sparse connections.

Purpose

To illustrate the applicability of the NMA in a complex network of surgical interventions and to prioritize the available interventions according to a clinically relevant outcome.

Methods

We considered RCTs of treatments for femoral neck fracture in adults. We searched CENTRAL, MEDLINE, EMBASE and ClinicalTrials.gov up to November 2015. Two reviewers independently selected trials, extracted data and used the Cochrane Collaboration’s tool for assessing the risk of bias. A group of orthopedic surgeons grouped similar but not identical interventions under the same node. We synthesized the network using a Bayesian network meta-analysis model. We derived posterior odds ratios (ORs) and 95% credible intervals (95% CrIs) for all possible pairwise comparisons. The primary outcome was all-cause revision surgery.

Results

Data from 27 trials were combined, for 4,186 participants (72% women, mean age 80 years, 95% displaced fractures). The median follow-up was 2 years. With hemiarthroplasty (HA) and total hip arthroplasty (THA) as a comparison, risk of surgical revision was significantly higher with the treatments unthreaded cervical osteosynthesis (OR 8.0 [95% CrI 3.6–15.5] and 5.9 [2.4–12.0], respectively), screw (9.4 [6.0–16.5] and 6.7 [3.9–13.6]) and plate (12.5 [5.8–23.8] and 7.8 [3.8–19.4]).

Conclusions

In older women with displaced femoral neck fractures, arthroplasty (HA and THA) is the most effective treatment in terms of risk of revision surgery.

Systematic Review Registration

PROSPERO no. CRD42013004218.

Level of Evidence

Network Meta-Analysis, Level 1.     

Slipped capital femoral epiphysis and hypothyroidism in a young adult: a case report

Introduction

Slipped capital femoral epiphysis is the most common hip disorder affecting the adolescent population, usually individuals between 8 and 15 years old. However, there are few case reports of older patients in the literature to date. It is believed that the etiology is multifactorial and may include obesity, trauma and, less frequently, endocrine pathologies comprising hypothyroidism, hypogonadism and panhypopituitarism.

Case presentation

We present the case of a 28-year-old Latino woman diagnosed with hypothyroidism secondary to arachnoidocele associated with skeletal immaturity and slipped capital femoral epiphysis.

Conclusions

It is important to conduct clinical and radiographic studies in these patients to rule out endocrine pathologies, especially hypothyroidism in those of sexual maturity.

Electronic supplementary material

The online version of this article (doi:10.1186/1752-1947-8-336) contains supplementary material, which is available to authorized users.     

Risk of Maltreatment-Related Injury: A Cross-Sectional Study of Children under Five Years Old Admitted to Hospital with a Head or Neck Injury or Fracture

Objectives

To determine the predictive value and sensitivity of demographic features and injuries (indicators) for maltreatment-related codes in hospital discharge records of children admitted with a head or neck injury or fracture.

Methods

Study design: Population-based, cross sectional study. Setting: NHS hospitals in England. Subjects: Children under five years old admitted acutely to hospital with head or neck injury or fracture. Data source: Hospital Episodes Statistics, 1997 to 2009. Main outcome measure: Maltreatment-related injury admissions, defined by ICD10 codes, were used to calculate for each indicator (demographic feature and/or type of injury): i) the predictive value (proportion of injury admissions that were maltreatment-related); ii) sensitivity (proportion of all maltreatment-related injury admissions with the indicator).

Results

Of 260,294 childhood admissions for fracture or head or neck injury, 3.2% (8,337) were maltreatment-related. With increasing age of the child, the predictive value for maltreatment-related injury declined but sensitivity increased. Half of the maltreatment-related admissions occurred in children older than one year, and 63% occurred in children with head injuries without fractures or intracranial injury.

Conclusions

Highly predictive injuries accounted for very few maltreatment-related admissions. Protocols that focus on high-risk injuries may miss the majority of maltreated children.     

3D non-linear analysis of the acetabular construct following impaction grafting

The study investigates the short-term behaviour of the acetabular construct following revision hip arthroplasty, carried out using the Slooff–Ling impaction grafting technique; using 3D finite element analyses. An elasto-plastic material model is used to describe the constitutive behaviour of morsellised cortico-cancellous bone (MCB) graft, since it has been shown that MCB undergoes significant plastic deformation under normal physiological loads. Based on previous experimental studies carried out by the authors and others, MCB is modelled using non-linear elasticity and Drucker Prager Cap (DPC) plasticity. Loading associated with walking, sitting down, and standing up is applied to the acetabular cup through a femoral head using smooth sliding surfaces. The analyses yield distinctive patterns of migration and rotation due to different activities. These are found to be similar to those observed in the clinical setting.     

3D non-linear analysis of the acetabular construct following impaction grafting

The study investigates the short-term behaviour of the acetabular construct following revision hip arthroplasty, carried out using the Slooff-Ling impaction grafting technique; using 3D finite element analyses. An elasto-plastic material model is used to describe the constitutive behaviour of morsellised cortico-cancellous bone (MCB) graft, since it has been shown that MCB undergoes significant plastic deformation under normal physiological loads. Based on previous experimental studies carried out by the authors and others, MCB is modelled using non-linear elasticity and Drucker Prager Cap (DPC) plasticity. Loading associated with walking, sitting down, and standing up is applied to the acetabular cup through a femoral head using smooth sliding surfaces. The analyses yield distinctive patterns of migration and rotation due to different activities. These are found to be similar to those observed in the clinical setting.     

Coffee Consumption and Risk of Fracture in the Cohort of Swedish Men (COSM)

Background

Recent research in a large cohort of women showed that coffee consumption is not associated with increased risk of fracture. Whether this is the case also among men is less clear.

Methods

In the Cohort of Swedish Men (COSM) study, 42,978 men aged 45–79 years old at baseline in 1997 answered a self-administered food frequency questionnaire covering coffee consumption and a medical and lifestyle questionnaire covering potential confounders. Our main outcomes first fracture at any site and first hip fracture were collected from the National Patient Registry in Sweden. The association between coffee consumption and fracture risk was investigated using Cox’s proportional hazards regression.

Results

During a mean follow-up of 11.2 years, 5,066 men had a first fracture at any site and of these, 1,186 (23%) were hip fractures. There was no association between increasing coffee consumption (per 200 ml) and rate of any fracture (hazard ratio [HR] 1.00; 95% confidence interval [CI] 0.99–1.02) or hip fracture (HR 1.02; 95% CI 0.99–1.06) after adjustment for potential confounders. For men consuming ≥4 cups of coffee/day compared to those consuming <1 cup of coffee/day, HR for any type of fracture was 0.91 (95% CI 0.80–1.02) and for hip fracture: 0.89 (95% CI 0.70–1.14).

Conclusions

High coffee consumption was not associated with an increased risk of fractures in this large cohort of Swedish men.     

Serum Metalloproteinases 2 and 9 as Predictors of Gait Status,Pressure Ulcer and Mortality after Hip Fracture

Introduction

The aim of this study is to evaluate the serum activity of metalloproteinases (MMPs) -2 and -9 as predictors of pressure ulcer (PU), gait status and mortality 6 months after hip fracture.

Methods

Eighty-seven patients over the age of 65 admitted to the orthopedic unit from January to December 2010 with hip fracture were prospectively evaluated. Upon admission, patient demographic information, including age, gender and concomitant diseases, was recorded. Blood samples were taken for analysis of MMP -2 and -9 activity by gel zymography and for biochemical examination within the first 72 hours of the patient’s admission, after clinical stabilization. The fracture pattern (neck, trochanteric or subtrochanteric), time from admission to surgery, surgery duration and length of hospital stay were also recorded.

Results

Two patients were excluded due to the presence of pathological fractures (related to cancer), and three patients were excluded due to the presence of PU before admission. Eighty-two patients, with a mean age of 80.4 ± 7.3 years, were included in the analysis. Among these patients, 75.6% were female, 59.8% had PU, and 13.4% died 6 months after hip fracture. All patients underwent hip fracture repair. In a univariate analysis, there were no differences in serum MMP activity between hip fracture patients with or without PU. In addition, the multiple logistic regression analysis models, which were adjusted by age, gender, length of hospital stay and C-reactive protein, showed that the pro-MMP-9 complexed with neutrophil gelatinase-associated lipocalin form (130 kDa) was associated with gait status recovery 6 months after hip fracture.

Conclusions

In conclusion, serum pro-MMP-9 is a predictor of gait status recovery 6 months after hip fracture.     

Cortical Hand Bone Porosity and Its Association with Distal Radius Fracture in Middle Aged and Elderly Women

Objective

Reduced bone mineral density (BMD), assessed by Dual Energy X-ray absorptiometry (DXA), is a well-known risk factor for fragility fracture. A large proportion of patients with fracture have only slightly reduced BMD. Assessment of other bone structure features than BMD may improve identification of individuals at increased fracture risk. Digital X-ray radiogrammetry (DXR), which is a feasible tool for measurement of metacarpal cortical bone density, also gives an estimate of cortical bone porosity. Our primary aim was to explore the association between cortical porosity in the hand assessed by DXR and distal radius fracture.

Methods

This case-control study included 123 women >50 years with distal radius fracture, and 170 controls. DXR was used to measure metacarpal BMD (DXR-BMD), cortical porosity (DXR-porosity), thickness (DXR-CT) and bone width (DXR-W) of the hand. Femoral neck BMD was measured by DXA.

Results

The fracture group had a statistically significant lower DXR-BMD (0.492 vs. 0.524 g/cm² p<0.001), higher cortical DXR-porosity (0.01256 vs. 0.01093, p<0.001), less DXR-CT (0.148 vs. 0.161cm, p<0.001) and lower femoral neck DXA-BMD (0.789 vs. 0.844 g/cm², p = 0.001) than the controls. In logistic regression analysis adjusted for age, a significant association with distal radius fracture (OR, 95% CI) was found for body mass index (0.930, 0.880–0.983), DXA-BMD (0.996, 0.995–0.999), DXR-BMD (0.990, 0.985–0.998), DXR-porosity (1.468, 1.278–1.687) and DXR-CT (0.997, 0.996–0.999). In an adjusted model, DXR-porosity remained the only variable associated with distal radius fracture (1.415, 1.194–1.677).

Conclusion

DXR derived porosity is associated with fracture at distal radius and might be a sensitive marker for skeletal fragility.     

Correlation between Parameters of Calcaneal Quantitative Ultrasound and Hip Structural Analysis in Osteoporotic Fracture Patients

Background

Calcaneal quantitative ultrasound (QUS), which is used in the evaluation of osteoporosis, is believed to be intimately associated with the characteristics of the proximal femur. However, the specific associations of calcaneal QUS with characteristics of the hip sub-regions remain unclear.

Design

A cross-sectional assessment of 53 osteoporotic patients was performed for the skeletal status of the heel and hip.

Methods

We prospectively enrolled 53 female osteoporotic patients with femoral fractures. Calcaneal QUS, dual energy X-ray absorptiometry (DXA), and hip structural analysis (HSA) were performed for each patient. Femoral heads were obtained during the surgery, and principal compressive trabeculae (PCT) were extracted by a three-dimensional printing technique-assisted method. Pearson’s correlation between QUS measurement with DXA, HSA-derived parameters and Young’s modulus were calculated in order to evaluate the specific association of QUS with the parameters for the hip sub-regions, including the femoral neck, trochanteric and Ward’s areas, and the femoral shaft, respectively.

Results

Significant correlations were found between estimated BMD (Est.BMD) and BMD of different sub-regions of proximal femur. However, the correlation coefficient of trochanteric area (r = 0.356, p = 0.009) was higher than that of the neck area (r = 0.297, p = 0.031) and total proximal femur (r = 0.291, p = 0.034). Furthermore, the quantitative ultrasound index (QUI) was significantly correlated with the HSA-derived parameters of the trochanteric area (r value: 0.315–0.356, all p<0.05) as well as with the Young’s modulus of PCT from the femoral head (r = 0.589, p<0.001).

Conclusion

The calcaneal bone had an intimate association with the trochanteric cancellous bone. To a certain extent, the parameters of the calcaneal QUS can reflect the characteristics of the trochanteric area of the proximal hip, although not specifically reflective of those of the femoral neck or shaft.     

The effects of femoral head size on the deformation of ultrahigh molecular weight polyethylene acetabular cups

Late loosening of cemented acetabular cups is increasingly being recognized as a clinical problem. One of the factors which may contribute to loosening is high localized deformation and stress at the cement-bone interface, the magnitude of which depends on the size of the total hip replacement (THR) femoral head. The effects of varying the femoral head size, from 22 to 32 mm, on strain values measured on the surface of the cup were investigated using experimental stress analysis techniques. The largest absolute strains were recorded when loading with the 22 mm head size. Peak strain values decreased to a minimum with the 26 mm head size and increased steadily with head sizes beyond 26 mm. The selection of an acetabular cup size and corresponding femoral head size in a total hip arthroplasty should not be an arbitrary one, but should be based on scientific studies which indicate minimum states of stress within the cup and cement mantle, as well as clinical evidence that the combination of components shows a reduced incidence of failure. This study experimentally quantifies the states of stress on the surface of the acetabular cup and points to the possible existence of an optimum component size to minimize surface stress.