A biomechanical enigma: why are tibial fractures not more frequent in the elderly?

Epidemiology revealed that diaphyseal fractures of the tibia affect young people, particularly young men; no increase was noticed for the elderly. This indicates that osteoporosis does not lead to increased bone fragility. Obviously, this is a biomechanical enigma. Torque measurements were carried out on human cadaveric tibiae and revealed a great correlation between the polar moment of inertia of the cortical bone at the tibial isthmus and the ultimate torque at failure (r = 0.83) and a lesser correlation between the cross-sectional density at the isthmus and the torque at failure (r = 0.57). Therefore, the size is more important than the degree of osteoporosis. We can speculate that endosteal resorption due to osteoporosis is compensated for by periosteal apposition and therefore does not lead to bone weakness.     

Positron emission tomography–computed tomography in the assessment of viability of femoral head in acetabular fractures

Purpose

The aim of this study was to use positron emission tomography–computed tomography (PET-CT) imaging as a tool for assessment of viability of femoral head in acetabular fractures and help in early detection of complications like avascular necrosis (AVN) of the femoral head.

Methods

In our study PET-CT was done pre-operatively and six weeks postoperatively in 31 patients who underwent open reduction and internal fixation (ORIF) of acetabular fractures and fracture–dislocations. There were 26 male and five female patients who were treated in our institute between January 2009 and July 2010. Patients were subsequently followed up with plain radiographs for a mean period of 3.8 years and minimum of two years.

Results

Although seven out of 31 patients showed avascularity of the femoral head on PET-CT in the pre-operative period, only two patients progressed to AVN at final follow up, whereas the other five patients regained the vascularity at the end of six weeks. There was no statistically significant correlation between vascular status on pre-operative scan and the presence of AVN on final follow-up radiograph. There was a significant correlation between avascularity of the femoral head on the sixth week PET-CT and AVN in the final radiograph.

Conclusion

PET-CT seems to be useful as a prognostic investigation in the assessment of the vascular status of the femoral head following injuries around the hip. Both pre-operative and postoperative imaging are necessary to understand the time-dependent changes in blood flow following injury.     

Impact of cement-augmented condylar screws in locking plate osteosynthesis for distal femoral fractures — A biomechanical analysis

IntroductionCompromised bone quality and the need for early mobilization continue to lead to implant failure in elderly patients with distal femoral fractures. The cement augmentation of screws might facilitate improving implant anchorage. The aim of this study was to analyse the impact of cement augmentation of the condylar screws on implant fixation in a human cadaveric bone model.Material and methodsTen pairs of osteoporotic femora (mean age: 90 years, range: 84–99 years) were used. A 2-cm gap osteotomy was created in the metaphyseal region to simulate an unstable AO/OTA 33-A3 fracture. All specimens were treated with a polyaxial locking plate. Specimens randomly assigned to the augmented group received an additional cement augmentation of the condylar screws using bone cement. A servohydraulic testing machine was used to perform incremental cyclic axial loading using a load-to-failure mode.ResultsAll specimens survived at least 800 N of axial compressive force. The mean compressive forces leading to failure were 1620 N (95% CI: 1382–1858 N) in the non-augmented group and 2420 N (95% CI: 2054–2786 N) in the group with cement-augmented condylar screws (p = 0.005).Deformation with cutting out of the condylar screws and condylar fracture were the most common reasons for failure in both groups. Whereas axial stiffness was comparable between both osteosyntheses (p = 0.508), significant differences were observed for the plastic deformation of the constructs (p = 0.014).ConclusionThe results of the present study showed that the cement augmentation of the condylar screws might be a promising technique for the fixation of distal femoral fractures in elderly patients with osteoporotic bones.     

The Kapandji technique for fixation of distal radius fractures – a biomechanical comparison of primary stability

The goal of this study was to compare Kapandji-K-wiring and established K-wiring techniques of the distal radius fracture for primary stability in a biomechanical model: dorsal K-wiring according to Kapandji using different angles of the K-wire, parallel and diagonal alignment of the K-wires. A new testing system which uses a synthetic material enabled us to carry out the cantilever bending test. By application of a lower load, the Kapandji procedure shows a higher reactive torque and stiffness. A higher reaction force of the other techniques, especially of the parallel wiring, are only observable under high-grade bending stress. Application of the Kapandji procedure with K-wires at a smaller angle to the axis of the radius results in the highest primary stability of the procedures investigated in the essential range of initial deformation. Received: 29 March 2000     

Prosthetic replacement in treatment of subcapital femoral neck fractures in the elderly

OBJECTIVE: To compare the results of femoral head replacement (FHR) and total hip replacement (THR) in treatment of subcapital femoral neck fractures (SFNF). METHODS: Between May 1987 and July 1998, 56 elderly patients (6 5-90 years; average 73.5 years) with SFNF were treated with prosthetic replacement. Six cases were treated with unipolar FHR, 18 cases with Bateman bipolar FHR, and 32 cases with Bateman bipolar THR. All domestic prostheses were installed with cement. RESULTS: There was no significant difference between the 2 groups in operating time and blood transfusion. Forty-nine patients were followed-up for an average of 5 years and 10 months. No wound infection or death was related to surgery. Complications in Group FHR were significantly higher than that i n Group THR. CONCLUSIONS: Since FHR is difficult to fit the bony acetabulum, it is only indicated for senile cases with poor conditions. However, the bi polar THR installed with cement is indicated for most elderly patients. Since th e femoral head and acetabulum can fit each other completely, it is more stable for taking weight-bearing earlier with less complications.     

Is there a benefit of proximal locking screws in osteoporotic distal radius fractures? – A biomechanical study

IntroductionThe distal radial fracture is a common fracture and frequently seen in geriatric patients. During the last years, volar plating has become a popular treatment option. While the application of locking screws at the distal fragment is widely accepted, there is no evidence for their use at the radial shaft.Materials and methodsIn six osteoporotic pairs of matched human cadaver radii an extra-articular model creating an AO 23-A2.1 fracture was employed. Osteosynthesis were performed using the APTUS 2.5 Adaptive TriLock Distal Radius System (Medartis AG) with locking (LS) or non-locking screws (NLS) for proximal fixation. Biomechanical testing was performed in a staircase fashion: starting with 50 cycles at 200 N, the load was continuously increased by 50 N every 80 cycles up to a maximum force of 400 N. Finally, load to failure was analyzed with failure defined as sudden loss of force measured (20%) or major deformation of the radii (10 mm).ResultsAt 200 N, 250 N, 300 N, 400 N and load to failure, the NLS group showed a higher degree of elastic modulus. In contrast, the LS group showed higher elastic modulus at 350 N. Maximum force was higher in the LS group without reaching statistical significance. Reasons for loss of fixation were longitudinal shaft fractures, horizontal peri-implant fractures and distal cutting out. No difference was seen between the two groups concerning the development of the above mentioned complications.ConclusionOur study did not show biomechanical superiority for distal radius fracture fixation by using locking screws in the proximal holes in an osteoporotic cadaver study. At load to failure, longitudinal shaft fractures and peri-implant fractures seemed to be a more relevant problem rather than failure of the proximal fixation.     

Low-energy distal radius fractures in middle-aged and elderly women—seasonal variations, prevalence of osteoporosis, and associates with fractures

Summary  

There is a lack of data on the prevalence of osteoporosis in patients with distal radius fractures occurring at the various seasons. The prevalence of osteoporosis is high, both in patients with indoor and outdoor fractures and higher than in controls. All female distal radius fracture patients ≥50 years should be referred for osteoporosis assessment.     

What is the value of 3D virtual reality in understanding acetabular fractures?

Background

Acetabular fractures are difficult to classify owing to the complex three-dimensional (3D) anatomy of the pelvis. 3D printing helps to understand and reliably classify acetabular fracture types. 3D-virtual reality (VR) may have comparable benefits. Our hypothesis is that 3D-VR is equivalent to 3D printing in understanding acetabular fracture patterns.

Methods

A total of 27 observers of various experience levels from several hospitals were requested to classify twenty 3D printed and VR models according to the Judet–Letournel classification. Additionally, surgeons were asked to state their preferred surgical approach and patient positioning. Time to classify each fracture type was recorded. The cases were randomized to rule out a learning curve. Inter-observer agreement was analyzed using Fleiss’ kappa statistics (κ).

Results

Inter-observer agreements varied by observer group and type of model used to classify the fracture: medical students: 3D print (κ = 0.61), VR (κ = 0.41); junior surgical residents: 3D print (0.51) VR (0.54); senior surgical residents: 3D print (0.66) VR (0.52); junior surgeons: 3D print (0.56), VR (0.43); senior surgeons: 3D print (κ = 0.59), VR (κ = 0.42).

Using 3D printed models, there was more agreement on the surgical approach (junior surgeons κ = 0.23, senior surgeons κ = 0.31) when compared with VR (junior surgeons κ = 0.17, senior surgeons 0.25). No difference was found in time used to classify these fractures between 3D printing and VR for all groups (P = 1.000).

Conclusions

The Judet–Letournel acetabular classification stays difficult to interpret; only moderate kappa agreements were found. We found 3D-VR inferior to 3D printing in classifying acetabular fractures. Furthermore, the current 3D-VR technology is still not practical for intra-operative use.

     

Japanese orthopedists’ interests in prevention of fractures in the elderly from falls

The aim of the present study was to survey the interest of Japanese orthopedists in preventing fractures in the elderly, and investigate their awareness with regard to main prevention strategies such as medications and hip protectors. From the list of 20,899 members of the Japanese Orthopedic Association, we randomly selected a sample of 2035 people. Each orthopedist was sent an anonymous survey consisting of 12 questions during July to August 2001. At that time, risedronate, raloxifene, and parathyroid hormone had not been approved for clinical use in Japan, and even alendronate had just been approved. Of the survey forms sent, 1011 responses were received, for a response rate of 50%. Analysis of these responses showed a very high interest in osteoporosis, fractures in the elderly from falls, and the prevention of such fractures. This interest was associated with physician age, with those above the age of 50 years being 2.3 times more likely to have an interest in each of these than physicians below that age. The respondents considered the most promising measure for the prevention of fractures in the elderly from falls to be fall prevention, followed by exercise and osteoporosis medications. The medication considered to be effective as a monotherapy by the overwhelming number of respondents was bisphosphonates, followed by vitamin D₃ and calcitonin. Combination agents cited were vitamin D₃, bisphosphonates, and calcitonin, in that order. Forty-two percent of respondents had some knowledge of hip protectors, but confidence in them as a means to prevent fractures was still low. The practical information from our survey should serve as a starting point for comparison to periods when new bisphosphonates or hip protectors become commonly available to Japanese orthopedists. The overall results indicate that Japanese orthopedists are very positive toward fracture prevention.     

Unipolar or bipolar hemiarthroplasty for femoral neck fractures in the elderly?

This prospective randomized trial compared the efficacy of unipolar versus bipolar hemiarthroplasty in elderly patients (> or = 65 years) with displaced femoral neck fractures in terms of quality of life and functional outcomes. One hundred fifteen patients with a mean age of 82.1 years were enrolled in this study and randomized to either unipolar or bipolar hemiarthroplasty. Quality of life and functional outcomes were assessed using the Musculoskeletal Functional Assessment instrument and Short Form-36 health survey. Seventy-eight patients completed 1 year of followup. There were no differences between the groups in estimated blood loss, length of hospital stay, mortality rate, number of dislocations, postoperative complications, or ambulatory status at 1 year. There also were no significant differences between the two groups at either point in postoperative Short Form-36 or Musculoskeletal Functional Assessment instrument scores. Results of this prospective randomized study suggest that the bipolar endoprosthesis provides no advantage in the treatment of displaced femoral neck fractures in elderly patients regarding quality of life and functional outcomes.     

Are there advances in the treatment of extracapsular hip fractures in the elderly?

While the rate of failure following hip fracture surgery for extracapsular hip fractures in the elderly is low, an incidence of implant cutout from the femoral head remains regardless of whether fixation is by sliding hip screw or intramedullary nail. In general, a well-executed osteosynthesis is the best assurance of a good outcome with few complications, and typically a less than ideal placement of the implant in the femoral head is the reason for cut-out and failure of the operation. It is clear that there is no difference in the incidence of complications or functional outcome between a sliding hip screw and an intramedullary nail for pertrochanteric fractures (AO/OTA 31-A1 and A2), while the implant of choice in the elderly for the true intertrochanteric fracture (AO/OTA 31-A3; reverse intertrochanteric) is a nail. However, what is less clear is whether there are newer ideas and/or implant designs that represent true advances in the treatment of extracapsular fractures in the elderly. The following review focuses on just this issue.     

Complex fractures of the proximal humerus in the elderly—outcome and complications after locking plate fixation

Open reduction and internal fixation (ORIF) with locking plates or primary arthroplasty remains a controversial issue in the management of complex proximal humerus fractures. Aim of this study was to evaluate the surgeon- and patient-based outcome of patients older than 65 years who underwent ORIF using locking plate fixation of a 3- or 4-part fracture of the proximal humerus. Twenty-seven patients older than 65 years were treated with locking plate fixation (PHILOS, Fa. Synthes, Umkirch, Germany). At an average follow-up of 44 months, the clinical and the subjective outcome were evaluated, and complications were analyzed. The mean age- and gender-related Constant score was 70% (30–100%) compared with 92% (47–108%) of the contralateral non-injured shoulder. The mean DASH score was 29 points (0–71). Five patients (18.5%) showed clinical signs of an impingement, which was related to malpositioning of the plate in 3 cases. Screw cutout was seen in 22.2% (6 patients). Avascular necrosis of the head or the tubercula was found in 8 patients (29.6%). The revision rate was 29.6%. However, the patients considered the functional status of their shoulder as “good” or “satisfactory.” The functional and patient-orientated results of the locking plate fixation of complex displaced proximal humerus fractures in the elderly are comparable to those of primary arthroplasty and minimally invasive treatment. Proper surgical technique (screw length, plate position) is mandatory for reducing the revision rate.     

Proximal femoral fractures in the elderly: how are we measuring outcome?

Introduction

Patients with proximal femoral fractures present a difficult problem to health care systems in view of their complex presentations and co-morbidities. Traditionally, the focus of outcome measurement for this patient group has been on mortality and surgical implant success. Increasing recognition of the need to diversify outcome measurements has led to the creation and use of a number of outcome scales. We sought to examine how these scales are being used in the current literature.

Methods

Abstracts to over 4000 papers related to proximal femoral fracture research were screened to identify commonly used scales in the five main categories of general quality of life measures (QoL), Activities of Daily Living scales (ADL), mobility and physical performance scales, disease-specific scales and hip-specific scales. The 14 identified scales were then searched for directly, and papers analysed for scale usage, timing and interpretation.

Results

ADL scales were the most commonly used group, followed by QoL measures, which are validated for elderly patients. Scale timing and use varied widely between studies. A large number of scales were found in addition to the 14 identified scales. None of the 14 identified scales were validated for the proximal femoral fracture population.

Discussion

A good scale must be appropriate in content, method and clinical utility. Its method of application must be reliable, responsive, and validated for the population in question. Outcome scale usage was difficult to assess in proximal femoral fracture research due to difficulties in isolating the relevant research, and in differences in scale timing and interpretation. Scale prevalence was skewed by use by specific research groups.

Conclusion

There is no single unifying scale in widespread use for proximal femoral fracture patients. We would recommend the validation of commonly used scales for this population, and would advise the use of scales from more than one category to assess outcome.     

Proximal humerus fractures in the elderly are we operating on too many?

Proximal humerus fractures in the elderly are a relatively rare injury, the treatment of which remains controversial, especially regarding Neer displaced two-part, and three-part and four-part fractures. Operative indications for most displaced proximal humerus fractures in the elderly remain poorly defined, but recent literature is actually supporting less aggressive approaches except for the most severe fractures. Recent epidemiological and larger scale retrospective studies fail to show a significant functional difference between operative and non-operative treatment of displaced two-part and three-part fractures in the elderly. Most four-part fractures appear to be best treated with hemiarthroplasty. Recent meta-analyses show a need for well-executed, randomized, prospective studies that can be used to provide evidence-based templates for appropriate management of displaced proximal humerus fractures in the elderly.     

Can we stop bone loss and prevent hip fractures in the elderly?

The two main determinants of hip fractures are falls and bone loss leading to an intrinsic femoral fragility. Substantial femoral bone loss continues throughout old age, with a continuous and exponential increase in the risk of hip fracture; thus any reduction or arrest of this loss will induce an important reduction in the incidence of hip fracture. Preventive measures may be achieved during childhood by increasing peak bone mass with calcium and exercise, by using long-term estrogen replacement therapy after menopause, but also by using vitamin D and calcium supplements for late prevention in the elderly. Vitamin D insufficiency and a deficit in calcium intake are very common in the elderly living either in institutions or at home and the cumulative response to these deficits is a negative calcium balance which stimulates parathyroid hormone secretion. This senile secondary hyperparathyroidism is one of the determinants of femoral bone loss and can be reversed by calcium and vitamin D supplements. We have shown in a 3-year controlled prospective study that the daily use of supplements (1.2 g calcium and 800 IU vitamin D₃) given in a large population of 3270 elderly ambulatory women living in nursing homes reduced the number of hip fractures by 23% (intention-to-treat analysis). In parallel, serum parathyroid hormone concentrations were reduced by 28% and low baseline serum 25-hydroxy vitamin D concentration returned to normal values. After 18 months of treatment the bone density of the total proximal femoral region had increased by 2.7% in the vitamin D₃-calcium group and decreased by 4.6% in the placebo group (p<0.001). this=" prevention=" is=" safe=" and=" can=" be=" recommended=" for=" people=" living=" in=" institutions.=" it=" could=" also=" be=" useful=" in=" other=" elderly=" subjects=" at=" particular=" risk=" due=" to=" a=" low=" calcium=" intake,=" an=" absence=" of=" solar=" exposure,=" a=" low=" femoral=" bone=" density,=" a=" high=" serum=" parathyroid=" hormone=" concentration,=" a=" low=" serum=" 25-hydroxyvitamin=" d=" concentration=" and=" a=" previous=" history=" of=" falls.=" prospective=" studies=" are=" needed=" for=" further=" evaluation=" of=" these=" risk=">