Osteopenic Bone Research Articles

Long-term management of the successful adult liver transplant: 2012 practice guideline by the American Association for the Study of Liver Diseases and the American Society of Transplantation

Michael R. Lucey, Norah Terrault, Lolu Ojo, J. Eileen Hay, James Neuberger, Emily Blumberg, and Lewis W. Teperman Division of Gastroenterology and Hepatology, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI; Gastroenterology Division, Department of Medicine, University of California San Francisco, San Francisco, CA; Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI; Mayo Clinic, Rochester, MN; Liver Unit, Queen Elizabeth Hospital, Birmingham, United Kingdom; Division of Infectious Diseases, University of Pennsylvania School of Medicine, Philadelphia, PA; and Department of Surgery, NYU Transplant Associates, New York, NY

Proximal humeral fractures: The role of calcium sulphate augmentation and extended deltoid splitting approach in internal fixation using locking plates

The aim of our study is to analyse the results of our surgical technique for the treatment of proximal humeral fractures and fracture dislocations using locking plates in conjunction with calcium sulphate bone-substitute augmentation and tuberosity repair using high-strength sutures. We used the extended deltoid-splitting approach for fracture patterns involving displacement of both lesser and greater tuberosities and for fracture-dislocations. Optimal surgical management of proximal humeral fractures remains controversial. Locking plates have become a popular method of fixation. However, failure of fixation may occur if they are used as the sole method of fixation in comminuted fractures, especially in osteopenic bone. MethodsWe retrospectively analysed 22 proximal humeral fractures in 21 patients; 10 were male and 11 female with an average age of 64.6 years (range 37–77). Average follow-up was 24 months. Eleven of these fractures were exposed by the extended deltoid-splitting approach. Fractures were classified according to Neer and Hertel systems. Preoperative radiographs and computed tomography (CT) scans in three- and four-part fractures were done to assess the displacement and medial calcar length for predicting the humeral head vascularity. According to the Neer classification, there were five two-part, six three-part, five four-part fractures and six fracture-dislocations (two anterior and four posterior). Results were assessed clinically with disabilities of the arm, shoulder and hand (DASH) scores, modified Constant and Murley scores and serial postoperative radiographs. ResultsThe mean DASH score was 16.18 and the modified Constant and Murley score was 64.04 at the last follow-up. Eighteen out of twenty-two cases achieved good clinical outcome. All the fractures united with no evidence of infection, failure of fixation, malunion, tuberosity failure, avascular necrosis or adverse reaction to calcium sulphate bone substitute. There was no evidence of axillary nerve injury. Four patients had a longer recovery period due to stiffness, associated wrist fracture and elbow dislocation. The CaSO4 bone substitute was replaced by normal appearing trabecular bone texture at an average of 6 months in all patients. ConclusionIn our experience, we have found the use of locking plates, calcium sulphate bone substitute and tuberosity repair with high-strength sutures to be a safe and reliable method of internal fixation for complex proximal humeral fractures and fracture-dislocations. Furthermore, we have also found the use of the extended deltoid-splitting approach to be safe and to provide excellent exposure facilitating accurate reduction for fixation of the fracture patterns involving displacement of both lesser and greater tuberosities and for fracture-dislocations.

Positive skeletal effects of cladrin, a naturally occurring dimethoxydaidzein, in osteopenic rats that were maintained after treatment discontinuation

Effects of cladrin treatment and withdrawal in osteopenic rats were studied. Cladrin improved trabecular microarchitecture, increased lumbar vertebral compressive strength, augmented coupled remodeling, and increased bone osteogenic genes. A significant skeletal gain was maintained 4weeks after cladrin withdrawal. Findings suggest that cladrin has significant positive skeletal effects. We showed that a standardized extract of Butea monosperma preserved trabecular bone mass in ovariectomized (OVx) rats. Cladrin, the most abundant bioactive compound of the extract, promoted peak bone mass achievement in growing rats by stimulating osteoblast function. Here, we studied the effects of cladrin treatment and withdrawal on the osteopenic bones. Adult female Sprague-Dawley rats were OVx and left untreated for 12weeks to allow for significant estrogen deficiency-induced bone loss, at which point cladrin (1 and 10mg/kg/day) was administered orally for another 12weeks. Half of the rats were killed at the end of the treatments and the other half at 4weeks after treatment withdrawal. Sham-operated rats and OVx rats treated with PTH or 17β-estradiol (E2) served as various controls. Efficacy was evaluated by bone microarchitecture using microcomputed tomographic analysis and fluorescent labeling of bone. qPCR and western blotting measured mRNA and protein levels in bone and uterus. Specific ELISA was used for measuring levels of serum PINP and urinary CTx. In osteopenic rats, cladrin treatment dose dependently improved trabecular microarchitecture, increased lumbar vertebral compression strength, bone formation rate (BFR), cortical thickness (Cs.Th), serum PINP levels, and expression of osteogenic genes in bones; and reduced expression of bone osteoclastogenic genes and urinary CTx levels. Cladrin had no uterine estrogenicity. Cladrin at 10mg/kg maintained acquired skeletal gains 4weeks after withdrawal. Cladrin had positive skeletal effects in osteopenic rats that were maintained after treatment withdrawal.

Locked Versus Standard Unlocked Plating of the Pubic Symphysis

Although locked plating has been shown to have advantages for diaphyseal and metaphyseal fracture fixation, its benefits for pubic symphyseal disruption have not been established. With traditional plate fixation of the disrupted pubic symphysis, normal physiological symphyseal pelvic motion eventually results in plate breakage, screw breakage, and loosening of screws. A concern exists that common modes of locked plate construct failure could result in abrupt and complete loss of symphyseal fixation. The purposes of this study were to determine, using an open-book pelvic injury model, whether locked plating of the pubic symphysis 1) offers any advantage over standard unlocked plating; and 2) results in a potential increased risk of abrupt fixation failure. Twelve osteopenic cadaver pelvic specimens were acquired and dual-energy x-ray absorptiometry scans were obtained to ensure uniformity of the specimens' bone density. Sacrospinous, sacrotuberous, and anterior sacroiliac ligaments were released and the symphysis pubis was transected to simulate a partially stable open book (AO/Orthopaedic Trauma Association 61-B3.1) injury. Using a six-hole 3.5-mm plate specifically designed for the symphysis pubis with the capability of fixation in locked or unlocked mode, six pelvises were fixed with locked screws and six pelvises were fixed standard unlocked bicortical screws. There was no significant difference between these 2 groups with regard to bone density (P = 0.47). Two equally osteopenic pelvic specimens from each fixation group were selected for the purpose of obtaining failure data and determining an acceptable load for trialing. Both specimens failed at 1985 N. The remaining 10 pelvises were then mounted on a materials testing apparatus using the bilateral stance model as described by Tile. In accordance with the failure data, each pelvis was stressed at 440 N for a total of one million cycles (equivalent to 6.5 months of daily walking) or until fixation failure. All pelvic specimens in both fixation groups completed one million cycles without plate or screw failure. However, diastasis of the initial pubic symphysis reduction was found in all pelvises (mean, 2.45 mm; range, 1.5-4.0 mm) regardless of fixation method. This loss of reduction was not significantly different between the 2 fixation groups (P = 0.914). No abrupt failures occurred in either plating group. Consequently, any fear of catastrophic (ie, abrupt and complete) failure of locked symphyseal plates appears to be unfounded for open-book injuries treated in patients with low bone density. However, minor loss of the symphyseal reduction was evident in all pelvises regardless of the fixation method. Therefore, locked plating of the pubic symphysis does not appear to offer any advantage over the standard unlocked technique for an AO/Orthopaedic Trauma Association 61-B3.1 partially stable open-book pelvic injury pattern in osteopenic bone.

Idiopathic Transient Osteoporosis of the Talus: A Cause for Unexplained Foot and Ankle Pain

A 53-year-old woman was investigated for several neoplastic, inflammatory, and infective conditions for her left foot, and ankle pain associated with swelling, which she developed unexpectedly without history of trauma or infection. Gross osteopenia in the talus raised the possibilities of several differential diagnoses, but a magnetic resonance imaging scan showed diffuse bone marrow edema in the talus. With negative infective and inflammatory markers, the condition was ultimately labeled as “transient osteoporosis.” She was reassured and followed up regularly. At the end of 12 months, she was completely asymptomatic, and her radiograph and magnetic resonance images showed significant improvement, with a normal-appearing talus and ankle joint, and there was complete resolution of bone marrow edema. Although “transient osteoporosis” of the foot is an uncommon condition, clinicians should be aware of this. Unexplained foot pain, with osteopenic bone and diffuse bone marrow edema on magnetic resonance imaging scan, is a feature of this condition. However, the diagnosis is established once other causes are excluded. The condition is self-limiting, and watchful expectancy of a normal recovery is the mainstay of treatment.

A proteomic study of protein variation between osteopenic and age-matched control bone tissue

The focus of this study was to identify changes in protein expression within the bone tissue environment between osteopenic and control bone tissue of human femoral neck patients with osteoarthritis. Femoral necks were compared from osteopenic patients and age-matched controls. A new method of bone protein extraction was developed to provide a swift, clear view of the bone proteome. Relative changes in protein expression between control and osteopenic samples were quantified using difference gel electrophoresis (DIGE) technology after affinity chromatographic depletion of albumin and IgG. The proteins that were determined to be differentially expressed were identified using standard liquid chromatography mass spectrometry (LC/MS/MS) and database searching techniques. In order to rule out blood contamination, blood from age-matched osteoporotic, osteopenic and controls were analyzed in a similar manner. Image analysis of the DIGE gels indicated that 145 spots in the osteopenic bone samples changed at least ± 1.5-fold from the control samples (P < 0.05). Three of the proteins were identified by LC/MS/MS. Of the proteins that increased in the osteopenic femurs, two were especially significant: carbonic anhydrase I and phosphoglycerate kinase 1. Apolipoprotein A-I was the most prominent protein that significantly decreased in the osteopenic femurs. The blood samples revealed no significant differences between groups for any of these proteins. In conclusion, carbonic anhydrase I, phosphoglycerate kinase 1 and apolipoprotein A-I appeared to be the most significant variations of proteins in patients with osteopenia and osteoarthritis.

Clinical and Radiological Results of PMMA-Augmented Pedicle Screws in Patient with Osteopenic Bone

Introduction: In osteopenic patients (e.g., osteoporosis, tumors), stability of transpedicular fixation can be increased by injection of polymethylmethacrylate (PMMA) through fenestrated screws. We have retrospectively analyzed a consecutive series of 15 patients (n = 15) treated with thoracic or lumbar PMMA-augmented pedicle screws, to determine the safety of the procedure and the stability of the implant.

Bisphosphonate treatment does not impair load adaptation in osteopenic mouse bones

Bisphosphonate treatment does not impair load adaptation in osteopenic mouse bones

Lack of CD47 leads to impaired bone cell differentiation and results in an osteopenic bone phenotype

Lack of CD47 leads to impaired bone cell differentiation and results in an osteopenic bone phenotype

Psoriatic arthritis or could it be Singleton-Merten syndrome?

Aims To describe Singleton-Merten Syndrome as an unusual cause of arthritis associated with a psoriasiform rash. Methods Case report. Results We present this case of a girl who at 11 months suffered from discrete red scaly areas on the trunk, limbs and scalp. She was given a diagnosis of psoriasis which remained poorly controlled throughout childhood, despite phototherapy and methotrexate treatment. In infancy, slow gross motor development was noted and felt to be related to hypermobility. She also began complaining of morning stiffness and pain in her hands and knees. The ESR was slightly raised at 17 but all other investigations were negative including ANA, rheumatoid factor and HLA-B27. X-rays showed osteopenic bones but no joint erosion. A diagnosis of psoriatic arthritis was made and although wheelchair bound, she never had significant joint inflammation. Dental concerns also emerged with delayed eruption and very malformed teeth with short roots. She was of proportional short stature with height at the 3rd centile at 10 years. At 11 years a systolic murmur was first heard although she had no cardiac symptoms. An echocardiograph revealed a moderately stenosed valve which rapidly progressed with syncopal episodes 18 months later. At this point the ejection fraction was 21% and a computed tomography scan revealed calcification of the aortic arch to the transverse arch. She had an aortic root replacement with pulmonary autograft. Around this time, she had repeat X-rays which were felt to not be typical of psoriatic arthritis. Instead they showed acro-osteolysis with periarticular osteopaenia, and medullary widening. Subsequently given her other clinical features, Singleton-Merten Syndrome was diagnosed. Conclusions Singleton-Merten Syndrome is a rare autosomal dominant multisystem condition with less than 10 cases reported in the literature. It is thought to be due to abnormal calcium deposition although its genetic basis is not known. Manifestations include aortic valve calcification, osteoporosis with widened medullary cavities, muscle weakness, short stature, psoriasiform eruptions, glaucoma and dentin dysplasia. Rheumatologists commonly treat arthropathies and therefore although this is a rare cause we hope to highlight awareness of this syndrome.

Vitamin D and Bone

All cells comprising the skeleton-chondrocytes, osteoblasts, and osteoclasts-contain both the vitamin D receptor and the enzyme CYP27B1 required for producing the active metabolite of vitamin D, 1,25 dihydroxyvitamin D. Direct effects of 25 hydroxyvitamin D and 1,25 dihydroxyvitamin D on these bone cells have been demonstrated. However, the major skeletal manifestations of vitamin D deficiency or mutations in the vitamin D receptor and CYP27B1, namely rickets and osteomalacia, can be corrected by increasing the intestinal absorption of calcium and phosphate, indicating the importance of indirect effects. On the other hand, these dietary manipulations do not reverse defects in osteoblast or osteoclast function that lead to osteopenic bone. This review discusses the relative importance of the direct versus indirect actions of vitamin D on bone, and provides guidelines for the clinical use of vitamin D to prevent/treat bone loss and fractures.

Cement Emerges As the Most Predictable Option for Hip Hemiarthroplasty

Commentary It happens every day in our hospitals. A frail eighty-five-year-old woman with various medical problems is admitted with a displaced femoral neck fracture. After the workup, she is deemed fit for surgery with recommendations to “minimize hypotension and keep the hematocrit above 30.” She is brought to the operating room late in the afternoon and the attending surgeon is asked, “Is this a cemented or press-fit hemiarthroplasty?” The surgeon is fond of the shorter procedure time and the supposedly reduced cardiovascular effects associated with cementless arthroplasty, which would be valuable for this frail patient. However, on reviewing the radiographs, the surgeon notes osteopenia and a wide, patulous femoral canal. The surgeon is worried about failing to obtain a good press-fit, causing an intraoperative fracture, or seeing subsidence on the follow-up postoperative radiographs. Up until now, he or she has had to base the decision on limited literature that primarily employed old Austin Moore implants. Taylor et al. have released the results of a randomized controlled trial comparing hemiarthroplasty with modern cemented and uncemented implants to treat a femoral neck fracture. One hundred and sixty patients were randomized, and outcomes were measured with use of validated functional outcome scores, visual analog pain scores, and complication rates. The results are quite compelling. The functional outcome scores were essentially the same in the two groups at six months and at one year postoperatively. The operating room time and intraoperative blood loss were virtually identical. The rate of cardiovascular and respiratory complications was identical. However, the uncemented group had significantly more orthopaedic technical problems than the cemented group. The uncemented group had a 7.5% rate of intraoperative fractures and a 15% rate of postoperative fractures within two years. No intraoperative fractures and one postoperative fracture were observed in the cemented group. These differences were both significant at the key p < 0.05 level. Subsidence occurred in 22.5% of the uncemented prostheses and 1.3% of the cemented prostheses (p < 0.001). The reoperation rate was similar in the two groups. The study had two significant limitations. First, forty-six patients were excluded from randomization because they were believed to be too frail for arthroplasty with cemented implants. Thus, the sickest population, which would in theory be most susceptible to cardiovascular collapse during placement of bone cement, was excluded. Unfortunately, this cohort represents the group in which surgeons are the most concerned about introducing bone cement, and the exclusion of these patients limits the generalizability of the study by biasing the study toward arthroplasty with cement. Second, the procedures were performed primarily by registrars. The technical complexity of press-fitting a femoral stem implant into osteopenic bone requires a degree of surgical experience before it can be properly employed. Therefore, studying inexperienced surgeons also biases the study toward arthroplasty with cement. That said, I submit that in the United States the majority of hip fracture care is undertaken by surgeons in the early stage of their practice, and it is rarely undertaken by surgeons who are dedicated to total joint replacement. What, then, should the surgeon in our example do? The reality is that there is support for use of both press-fit and cemented hemiarthroplasty components for the treatment of femoral neck fractures. Given the multiple frailties and comorbidities of the population with such fractures, their true independence and functional status after the surgery probably has little to do with whether the prosthesis is fixed with cement or a press-fit interface, as long as a stable construct is obtained. Knowing that the functional results of the two procedures were very similar, and that we are unlikely to have larger studies to identify a clinically meaningful difference, the decision-making perspective shifts toward choosing a procedure that causes the least complications. The results of the study by Taylor et al. demonstrate that obtaining a good press-fit in patients treated with hemiarthroplasty for hip fracture is challenging (as demonstrated by the higher intraoperative fracture rate and higher rate of postoperative subsidence) and that the purported benefits of shorter operating room time and lower blood loss are nonexistent. Hemiarthroplasty with cement remains the gold standard against which all other procedures must be measured.

Evaluation of trabecular microarchitecture in nonosteoporotic postmenopausal women with and without fracture

This study compared microscopic magnetic resonance imaging (µMRI) parameters of trabecular microarchitecture between postmenopausal women with and without fracture who have normal or osteopenic bone mineral density (BMD) on dual-energy X-ray absorptiometry (DXA). It included 36 postmenopausal white women 50 years of age and older with normal or osteopenic BMD (T-scores better than -2.5 at the lumbar spine, proximal femur, and one-third radius on DXA). Eighteen women had a history of low-energy fracture, whereas 18 women had no history of fracture and served as an age, race, and ultradistal radius BMD-matched control group. A three-dimensional fast large-angle spin-echo (FLASE) sequence with 137 µm × 137 µm × 400 µm resolution was performed through the nondominant wrist of all 36 women using the same 1.5T scanner. The high-resolution images were used to measure trabecular bone volume fraction, trabecular thickness, surface-to-curve ratio, and erosion index. Wilcoxon signed-rank tests were used to compare differences in BMD and µMRI parameters between postmenopausal women with and without fracture. Post-menopausal women with fracture had significantly lower (p < 0.05) trabecular bone volume fraction and surface-to-curve ratio and significantly higher (p < 0.05) erosion index than postmenopausal women without fracture. There was no significant difference between postmenopausal women with and without fracture in trabecular thickness (p = 0.80) and BMD of the spine (p = 0.21), proximal femur (p = 0.19), one-third radius (p = 0.47), and ultradistal radius (p = 0.90). Postmenopausal women with normal or osteopenic BMD who had a history of low-energy fracture had significantly different (p < 0.05) µMRI parameters than an age, race, and ultradistal radius BMD-matched control group of postmenopausal women with no history of fracture. Our study suggests that µMRI can be used to identify individuals without a DXA-based diagnosis of osteoporosis who have impaired trabecular microarchitecture and thus a heretofore-unappreciated elevated fracture risk.

Osteoblast-specific overexpression of human interleukin-7 rescues the bone mass phenotype of interleukin-7–deficient female mice

Interleukin-7 is a critical cytokine for lymphoid development and a direct inhibitor of in vitro osteoclastogenesis in murine bone marrow cultures. To explore the role of IL-7 in bone, we generated transgenic mouse lines bearing the 2.3-kb rat collagen 1α1 promoter driving the expression of human IL-7 specifically in osteoblasts. In addition, we crossed these mice with IL-7-deficient mice to determine if the alterations in lymphopoiesis, bone mass, and osteoclast formation observed in the IL-7 knockout (KO) mice could be rescued by osteoblast-specific overexpression of IL-7. Here, we show that mice overexpressing human IL-7 in the osteoblast lineage showed increased trabecular bone volume in vivo by µCT and decreased osteoclast formation in vitro. Furthermore, targeted overexpression of IL-7 in osteoblasts rescued the osteopenic bone phenotype and B-cell development of IL-7 KO mice but did not have an effect on T lymphopoiesis, which occurs in the periphery. The bone phenotypes in IL-7 KO mice and targeted IL-7-overexpressing mouse models were observed only in females. These results likely reflect both direct inhibitory effects of IL-7 on osteoclastogenesis in vivo and sex-specific differences in responses to IL-7.

Combination of Micronutrients for Bone (COMB) Study: Bone Density after Micronutrient Intervention

Along with other investigations, patients presenting to an environmental health clinic with various chronic conditions were assessed for bone health status. Individuals with compromised bone strength were educated about skeletal health issues and provided with therapeutic options for potential amelioration of their bone health. Patients who declined pharmacotherapy or who previously experienced failure of drug treatment were offered other options including supplemental micronutrients identified in the medical literature as sometimes having a positive impact on bone mineral density (BMD). After 12 months of consecutive supplemental micronutrient therapy with a combination that included vitamin D3, vitamin K2, strontium, magnesium and docosahexaenoic acid (DHA), repeat bone densitometry was performed. The results were analyzed in a group of compliant patients and demonstrate improved BMD in patients classified with normal, osteopenic and osteoporotic bone density. According to the results, this combined micronutrient supplementation regimen appears to be at least as effective as bisphosphonates or strontium ranelate in raising BMD levels in hip, spine, and femoral neck sites. No fractures occurred in the group taking the micronutrient protocol. This micronutrient regimen also appears to show efficacy in individuals where bisphosphonate therapy was previously unsuccessful in maintaining or raising BMD. Prospective clinical trials are required to confirm efficacy.

Hemiarthroplasty for Three- and Four-part Proximal Humerus Fractures

Displaced three- and four-part proximal humerus fractures are among the most challenging shoulder conditions to manage. Because of the risk of symptomatic malunion, nonunion, and humeral head osteonecrosis, surgical management is preferred. Locking plate technology has provided an alternative to hemiarthroplasty for certain three- and four-part fracture patterns, even in the setting of osteopenic bone. Prosthetic humeral head replacement has been advocated for head-splitting fractures and fracture-dislocations as well as four-part fractures with significant initial varus displacement (>20°). Technical challenges, including obtaining proper humeral head height, retroversion, and optimal positioning and fixation of the tuberosities, have a substantial effect on patient outcomes.

Hemiarthroplasty for Three- and Four-part Proximal Humerus Fractures

Displaced three- and four-part proximal humerus fractures are among the most challenging shoulder conditions to manage. Because of the risk of symptomatic malunion, nonunion, and humeral head osteonecrosis, surgical management is preferred. Locking plate technology has provided an alternative to hemiarthroplasty for certain three- and four-part fracture patterns, even in the setting of osteopenic bone. Prosthetic humeral head replacement has been advocated for head-splitting fractures and fracture-dislocations as well as four-part fractures with significant initial varus displacement (>20°). Technical challenges, including obtaining proper humeral head height, retroversion, and optimal positioning and fixation of the tuberosities, have a substantial effect on patient outcomes.

Does Using Autograft Bone Chips Achieve Consistent Bone Ingrowth in Primary TKA?

Cementless fixation remains controversial in TKA due to the challenge of achieving consistent skeletal attachment. Factors predicting durable fixation are not clearly understood, but we presumed bone ingrowth could be enhanced by the quantity of host bone and application of autograft bone chips. We asked: (1) Did the amount of bone ingrowth exceed the amount of periprosthetic and host bone with the addition of autograft bone chips? (2) Did the amount of bone ingrowth increase with implantation time? And (3) did osteolysis along the porous-coated interface and screw tracts progress with implantation time? We measured the amount of bone in the porous-coated, periprosthetic, and host bone regions in 19 postmortem retrieved cementless primary total knee implants. The amount of bone in apposition to the implant surface, and alternatively lysed bone, was analyzed radiographically to assess the progression of osteolysis. While bone ingrowth tended to be less than periprosthetic and host bone in all three components, it was only significantly less in the patellar component. Bone ingrowth increased in all three components over time, but progression of osteolysis did not. Even after long-term followup, the amount of bone ingrowth did not surpass host bone levels, suggesting the amount of a patient's host bone is a limiting factor in the amount of bone ingrowth achievable for this cementless design. It remains unknown whether compromised osteopenic bone could achieve the amount of bone attachment necessary to provide durable fixation over time.

Acute total hip replacement combined with open reduction internal fixation (ORIF) for the management of acetabular fracture in the elderly

The elderly patient with an acetabular fracture presents a unique surgical challenge because of medical comorbidities, decreased physiological reserve, reduced healing capacity, osteopenic bone, and atypical fracture patterns. Goals include rapid mobilization, early weight bearing, and a pain-free functional hip. Treatment options include initial nonoperative management with delayed total hip arthroplasty (THA), open reduction and internal fixation (ORIF), minimally invasive osteosynthesis, and acute total hip replacement combined with ORIF. Advantages of acute THA combined with ORIF in the elderly patient include the potential for 1-stage treatment with faster recovery and the avoidance of problems that can occur with delayed arthroplasty. Disadvantages include major technical challenges of simultaneously obtaining both implant and fracture stability. This review discusses the indications, contraindications, technique, and results of acute THA combined with ORIF for the management of acetabular fractures in the elderly. The technique for combined surgical treatment of an associated posterior wall/posterior column acetabular fracture with an ipsilateral femoral neck fracture is described.

A New System to Improve Screw Fixation to Bones

Plates and non-locked screws used in the treatment of osteoporotic bone fractures frequently become loose due to everyday mechanical demands. Currently, locking plates and screws are the gold standard treatment for these fractures. However, their use has several limitations and complications as they are technically demanding, and their cost is very expensive. To improve the fixation strength of traditional unlocked plate and screw constructs, we have developed a new fixation system based on a very old concept. The system consists of a screw locking element (SLE) manufactured from PEEK, which is attached to the end of the screw shaft once it has traversed both bone cortices. A specially designed tool is used to facilitate its attachment to the screw. This tool makes it possible for the screw to traverse an osteosynthesis plate or lockwasher as well as both bone cortices and to easily find the SLE, fixing it against the far cortex. We tested the pull-out strength of SLEs and compared the results with previously published data for human femoral cortex pull-out strength. Our laboratory tests demonstrate that the mean SLE pull-out strength was 3864 ± 47.61 N, while that observed for a human femoral diaphysis cortex was 4071.54 ± 1461.69 N. This difference was not significant (p &gt; 0.05). This new system can easily be used with any type of osteosynthesis in osteoporotic or osteopenic bones, with the screws being placed on weakened areas of the bone (e.g., fissure lines, previous orifices, or thinned metaphyseal bone cortex), or to replace over-torqued screws. It is particularly suitable for veterinary trauma, where immediate weight-bearing protection after fracture treatment is nearly impossible.