Ascorbic acid reduces Ropivacaine-induced myotoxicity in cultured human osteoporotic skeletal muscle cells.

BACKGROUND: Osteoporosis is a worldwide health issue. Loss of bone mass is a potential risk factor for fragility fractures, and osteoporotic fractures place a considerable burden on society. Bone and muscle represent a functional unit in which the two tissues are intimately interconnected. Ropivacaine is a potent local anesthetic used in clinical practice for intraoperative anesthesia and postoperative pain management, in particular for hip surgery. When injected, Ropivacaine can diffuse locally through, in particular in surrounding skeletal muscle tissue, causing dose-dependent cytotoxicity, oxidative stress and myogenesis impairment. Based on those evidences, we focused our attention on Ropivacaine-induced cytotoxicity on cultured human myoblasts. METHODS: Primary human myoblasts and myotubes from healthy subjects, osteoarthritic and osteoporotic patients (OP) were cultured in the presence of Ropivacaine. In some experiments, ascorbic acid (AsA) was added as a potent antioxidant agent. Cell viability and ROS levels were evaluated to investigate the myotoxic activity and Real-Time PCR and Western blot analysis carried out to investigate the expression of proliferation and myogenic markers. RESULTS: A dose-dependent decrease of cell viability was observed after Ropivacaine exposure in both OP myoblasts and myotubes cultures, whereas those effects were not observed in the presence of Propofol, a general anesthetic. The adding of AsA reduced Ropivacaine negative effects in OP myoblast cultures. In addition, Ropivacaine exposure also increased ROS levels and upregulated Nox4 expression, an enzyme primarily implicated in skeletal muscle ROS generation. AsA treatment counteracted the oxidant activity of Ropivacaine and partially restored the basal condition in cultures. Positive myogenic markers, such as MyoD and Myf5, were downregulated by Ropivacaine exposure, whereas myostatin, a negative regulator of muscle growth and differentiation, was upregulated. The phenotypic deregulation of myogenic controllers in the presence of Ropivacaine was counteracted by AsA treatment. CONCLUSIONS: Our findings highlight the oxidative stress-mediated myotoxic effect of Ropivacaine on human skeletal muscle tissue cell cultures, and suggest treatment with AsA as valid strategy to mitigate its negative effects and allowing an ameliorated functional skeletal muscle recovery in patients undergoing hip replacement surgery for osteoporotic bone fracture.

Gaps and alternative surgical and non-surgical approaches in the bone fragility management: an updated review.

Osteoporotic fractures are one of the major problems facing healthcare systems worldwide. Undoubtedly, fragility fractures of the hip represent a far greater burden in terms of morbidity, mortality, and healthcare costs than other fracture sites. However, despite the significant impact on the health and quality of life of older adults, there is a general lack of awareness of osteoporosis, which results in suboptimal care. In fact, most high-risk individuals are never identified and do not receive adequate treatment, leading to further fragility fractures and worsening health status. Furthermore, considering the substantial treatment gap and the proven cost-effectiveness of fracture prevention programs such as Fracture Liaison Services, urgent action is needed to ensure that all individuals at high risk of fragility fracture are adequately assessed and treated. Based on this evidence, the aim of our review was to (i) provide an overview and comparison of the burden and management of fragility fractures, highlighting the main gaps, and (ii) highlight the importance of using alternative approaches, both surgical and non-surgical, with the aim of implementing early prevention of osteoporotic fractures and improving the management of osteoporotic patients at imminent and/or very high risk of fracture.

Augmentation in fragility fractures, bone of contention: a systematic review.

BACKGROUND: Osteoporosis is a complex multifactorial disease characterized by reduced bone mass and microarchitectural deterioration of bone tissue linked to an increase of fracture risk. Fragility fractures occur in osteoporotic subjects due to low-energy trauma. Osteoporotic patients are a challenge regarding the correct surgical planning, as it can include fixation augmentation techniques to reach a more stable anchorage of the implant, possibly lowering re-intervention rate and in-hospital stay. METHODS: The PubMed database and the Google Scholar search engine were used to identify articles on all augmentation techniques and their association with fragility fractures until January 2022. In total, we selected 40 articles that included studies focusing on humerus, hip, spine, and tibia. RESULTS: Literature review showed a quantity of materials that can be used for reconstruction of bone defects in fragility fractures in different anatomic locations, with good results over the stability and strength of the implant anchorage, when compared to non-augmented fractures. CONCLUSION: Nowadays there are no recommendations and no consensus about the use of augmentation techniques in osteoporotic fractures. Our literature review points at implementing the use of bone augmentation techniques with a specific indication for elderly patients with comminuted fractures and poor bone quality.

DNA Methylation Signatures of Bone Metabolism in Osteoporosis and Osteoarthritis Aging-Related Diseases: An Updated Review.

DNA methylation is one of the most studied epigenetic mechanisms that play a pivotal role in regulating gene expression. The epigenetic component is strongly involved in aging-bone diseases, such as osteoporosis and osteoarthritis. Both are complex multi-factorial late-onset disorders that represent a globally widespread health problem, highlighting a crucial point of investigations in many scientific studies. In recent years, new findings on the role of DNA methylation in the pathogenesis of aging-bone diseases have emerged. The aim of this systematic review is to update knowledge in the field of DNA methylation associated with osteoporosis and osteoarthritis, focusing on the specific tissues involved in both pathological conditions.

Skeletal System Biology and Smoke Damage: From Basic Science to Medical Clinic.

Cigarette smoking has a negative impact on the skeletal system, as it reduces bone mass and increases fracture risk through its direct or indirect effects on bone remodeling. Recent evidence demonstrates that smoking causes an imbalance in bone turnover, making bone vulnerable to osteoporosis and fragility fractures. Moreover, cigarette smoking is known to have deleterious effects on fracture healing, as a positive correlation between the daily number of cigarettes smoked and years of exposure has been shown, even though the underlying mechanisms are not fully understood. It is also well known that smoking causes several medical/surgical complications responsible for longer hospital stays and a consequent increase in the consumption of resources. Smoking cessation is, therefore, highly advisable to prevent the onset of bone metabolic disease. However, even with cessation, some of the consequences appear to continue for decades afterwards. Based on this evidence, the aim of our review was to evaluate the impact of smoking on the skeletal system, especially on bone fractures, and to identify the pathophysiological mechanisms responsible for the impairment of fracture healing. Since smoking is a major public health concern, understanding the association between cigarette smoking and the occurrence of bone disease is necessary in order to identify potential new targets for intervention.

Reviewing Bone Marrow Edema in Athletes: A Difficult Diagnostic and Clinical Approach.

Bone marrow edema (BME) is defined as an area of low signal intensity on T1-weighted (T1W) MRI images and associated with intermediate or high signal intensity findings on T2-weighted (T2W) MRI images. BME represents a typical imaging finding that characterizes common stress-related bone injuries of professional and amateur athletes. The etiology of stress-related injuries is influenced by numerous factors, including the initiation of a new sports activity or changes in an existing training protocol. The clinical significance of BME remains unclear. However, a correlation between the imaging pattern of BME, the clinical history of the patient and the type of sports activity practiced is essential for correct diagnosis and adequate therapeutic treatment. It is also important to clarify whether there is a specific threshold beyond which exercise can adversely affect the bone remodeling process, as the clinical picture may degenerate into the presence of BME, pain and, in the most severe cases, bone loss. In our review, we summarize the current knowledge on the etiopathogenesis and treatment options for BME and highlight the main aspects that make it difficult to formulate a correct diagnosis and establish an adequate therapeutic treatment.

Effects of Simulated Microgravity on Muscle Stem Cells Activity.

BACKGROUND/AIMS: The study of the effects of simulated microgravity on primary cultures of human satellite cells represents a reliable model for identifying the biomolecular processes involved in mechanic load-related muscle mass loss. Therefore, this study aims to investigate the role of myostatin and Bone Morphogenetic Protein-2 in human satellite cells response to simulated microgravity condition. METHODS: In order to identify the main molecules involved in the phenomena of degeneration/regeneration of muscle tissue related to the alteration of mechanic load, we performed a morphological and immunohistochemical study on 27 muscle biopsies taken from control, osteoporotic and osteoarthritic patients, underwent hip arthroplasty. For each patient, we set up primary satellite cell cultures subjected to normogravity and simulated microgravity (110h) regimens. Cellular functionality has been studied through a morphological evaluation performed by optical microscopy, and an ultrastructural evaluation carried out by transmission electron microscopy. Furthermore, we evaluated the expression of Bone Morphogenetic Protein-2 and myostatin through immunocytochemical reactions. RESULTS: Our results showed that in the very early phases of simulated microgravity condition the satellite cells are more active than those subjected to the normogravity regime, as demonstrated by both the increase in the number of myotubes and the significant increase in the expression of Bone Morphogenetic Protein-2 in all experimental groups. However, with prolongated exposure to simulated microgravity regime (>72h), satellite cells and new formed myotubes underwent to cell death. It is important to note that, in early phases, simulated microgravity can stimulate the formation of new myotubes from satellite cells derived by osteoporotic patients. Furthermore, we observed that simulated microgravity can induce changes in myostatin expression levels by group-dependent variations. CONCLUSION: The results obtained allowed us to hypothesize a possible molecular mechanism of response to simulated microgravity, confirming the importance of Bone Morphogenetic Protein-2 and myostatin in the physio-pathogenesis of muscle tissue. In addition, these data can lay the foundation for new therapeutic approached in the prevention/cure of osteoporosis and sarcopenia.

Differences between muscle from osteoporotic and osteoarthritic subjects: in vitro study by diffusion-tensor MRI and histological findings.

BACKGROUND: Osteoarthritis and osteoporosis are strongly coupled with alterations of muscles quality and fats metabolism. However, there are no studies for investigating possible differences between osteoporotic and osteoarthritic muscles. Understanding muscle-bone and muscle-cartilage interactions would be of high clinical value. AIM: Investigate potential microstructural and physiological differences between osteoporotic and osteoarthritic muscles by diffusion Nuclear Magnetic Resonance (NMR) imaging (diffusion MRI) and histological findings. METHODS: Vastus-lateralis muscles excised from osteoporotic (n = 26, T Score < - 2.5, Kellgren-Lawrence ≤ 2) and osteoarthritic (n = 26, T Score > - 2.5, Kellgren--Lawrence 3 and 4) age-matched women were investigated by NMR relaxometry, diffusion-tensor imaging (DTI) at 9.4 T, and histological techniques. Intramyocellular (IMCL) and extramyocellular (EMCL) lipid were quantified. The percentage and mean diameters of fibers I and II were evaluated. Relationship between mean diffusivity (MD), fractional anisotropy (FA), the DTI eigenvalues (λ1, λ2, λ3), histological findings in muscles and clinical data (Kellgren-Lawrence and T score, age, menopausal age, body mass index) were studied. Pairwise comparisons between groups were made using one-way analysis of variance and correlation between variables was assessed with linear correlation analysis (Pearson's r coefficient). RESULTS: Osteoporotic muscles showed higher MD, λ1, λ2, λ3 compared to osteoarthritis ones. This is explainable with a significant higher density of IMCL droplets found inside the osteoarthritic muscles and a large amount of fibrotic tissue and IMCL infiltration between fibers, i.e. in endomysium and perimysium that lead to a more hindered diffusion. Furthermore, histological analysis suggests mitochondrial degeneration as the origin of the greatest amount of IMCL droplets in osteoarthritic muscles. CONCLUSION: This work highlights differences between muscles of osteoporotic and osteoarthritic subjects that can be quantified by NMR DTI investigations.

Bone Morphogenetic Proteins and myostatin pathways: key mediator of human sarcopenia.

BACKGROUND: Sarcopenia, osteoporosis and osteoarthritis are the most frequent musculoskeletal disorders affecting older people. The main aim of this study was to test the hypothesis that the balance between BMPs and myostatin pathways regulates the age-related muscle degeneration in OP and OA patients. To this end, we investigated the relationship among the expression of BMP-2/4-7, myostatin and phosphorylated Smads1-5-8 and the muscle quality, evaluated in term of fibers atrophy and satellite cells activity. METHODS: In this retrospective study, we collected 123 biopsies of vastus lateralis: 48 biopsies from patients who underwent hip arthroplasty for subcapital fractures of the femur (OP), 55 biopsies from patients who underwent hip arthroplasty for osteoarthritis (OA) and 20 biopsies from patients who underwent hip arthroplasty for high-energy hip fractures (CTRL). Muscle biopsies were fixed in 4% paraformaldehyde and paraffin embedded. Serial sections were used for morphometrical and immunohistochemical analysis (BMP/2/4-7, myostatin, Smads1-5-8, Pax7 and myogenin). In addition, 1 mm3 of muscle tissue of each patient was embedded in epon for ultrastructural study. RESULTS: Morphometric data indicated an increase of the number of atrophic fibers in OP patients compare to OA. In line with these data, we found an high regenerative potential in muscle tissues of OA patients due to the significant amount of both Pax7 and myogenin positive satellite cells detected in OA group. In addition, our data showed the decrease of BMP2/4 and -7 expression in OP patients compared to both OA group and CTRL. Conversely, OP patients were characterized by high levels of myostatin expression. A different expression profile was also found for phosphorylated Smad1-5-8 between OP and OA patients. In particular, OP patients showed a low number of positive phosphorylated Smad1-5-8 nuclei. CONCLUSION: The identification of molecular pathways involved in the pathogenesis of sarcopenia open new prospective for the development of drugs able to prevent/treat the muscle impairment that occur in elderly. Results here reported, highlighting the role of BMPs and myostatin pathways in physio-pathogenesis of human sarcopenia, allow us to propose human recombinant BMP-2/7 and anti-myostatin antibodies as a possible therapeutic option for the sarcopenia.

Heavy metals accumulation affects bone microarchitecture in osteoporotic patients.

Bone metabolism is affected by mechanical, genetic, and environmental factors and plays a major role in osteoporosis. Nevertheless, the influence of environmental pollution on the occurrence of osteoporosis is still unclear and controversial. In this context, heavy metals are the most important pollutants capable to affect bone mass. The aim of this study was to investigate whether heavy metals accumulation in bone tissues could be related to the altered bone metabolism and architecture of osteoporotic patients. To this end, we analyzed 25 bone head biopsies osteoporotic patients and 25 bone head biopsies of osteoarthritic patients. Moreover we enrolled 15 patients underwent hip arthroplasty for high-energy hip fracture or osteonecrosis of the femoral head as a control group. Bone head biopsies were studied by BioQuant-osteo software, scanning electron microscopy and Energy Dispersive X-ray microanalysis. We found a prevalence of lead, cadmium and chromium accumulation in osteoporotic patients. Noteworthy, high levels of sclerostin, detected by immunohistochemistry, correlate with the accumulation of heavy metal found in the bone of osteoporotic patients, suggesting a molecular link between heavy metal accumulation and bone metabolism impairment. In conclusion, the presence of heavy metals into bone shed new light on the comprehension of the pathogenesis of osteoporosis since these elements could play a non redundant role in the development of osteoporosis at cellular/molecular and epigenetic level. Nevertheless, in vivo and in vitro studies need to better elucidate the molecular mechanism in which heavy metals can participate to osteoporosis. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1333-1342, 2017.

Densitometric evaluation of bone remodelling around Trabecular Metal Primary stem: a 24-month follow-up.

BACKGROUND: Today, an increasing number of total hip arthroplasty (THA) procedures are being performed. Osseointegration is a physiological phenomenon that leads to the direct anchorage of an implant by the formation of bony tissue around the implant without the growth of fibrous tissue at the bone-implant interface. Several factors may affect this phenomenon: some of these depend on the patient and others may depend on implant design and materials. Variations in periprosthetic bone mineral density (BMD) can be studied through several scans by dual energy X-ray absorptiometry (DEXA) around the femoral stem. AIMS: The purpose of this study is to investigate correlations between periprosthetic BMD and the factors affecting osseointegration. METHODS: We retrospectively analysed patients who underwent primary THA. In all the patients, Trabecular Metal Primary (TMP), a standard uncemented tapered stem with a proximal porous tantalum coating, was implanted. Preoperatively, postoperatively, 3 and 6 months, 1 year and 2 years after implantation, DEXA scans were performed around the femoral stem. The patients were matched for diagnosis, sex, BMD of the lumbar spine and contralateral femur, Body Mass Index and age. RESULTS: One hundred and eight patients (51 males and 57 females) with a mean age of 73 years were studied. Different BMD changing patterns were observed and a greater bone resorption was noted in all the conditions associated with poor bone quality. DISCUSSION: The proximal coating of Trabecular Metal Primary (TMP) seemed to be effective in promoting new bone formation in the proximal femur also in the conditions associated with poor bone quality. CONCLUSIONS: At the present time, DEXA is considered the most reliable tool for evaluating bone remodelling after THA.

Sarcopenia: a histological and immunohistochemical study on age-related muscle impairment.

BACKGROUND: Sarcopenia and osteoporosis increase the risk of bone fracture in the elderly due to the loss of muscle mass and the decrease in bone mineral density. Myostatin and Bone Morphogenetic Proteins (BMPs) are important molecules involved in muscle mass homeostasis. AIM: In this study, we investigated the role of BMP4 and myostatin in the pathophysiogenesis of sarcopenia related to osteoporosis and osteoarthritis. METHODS: Muscle atrophy, BMP4 and myostatin expression were evaluated in 27 biopsies of osteoarthritic (OA) women and 27 biopsies from osteoporotic (OP) group by immunohistochemical reaction. Muscle stem cell niches were investigated by transmission electron microscopy analysis. RESULTS: Myostatin and BMP4 expression was evaluated by counting the number of positive fibers on 25 high-power field. We found that OA muscle biopsies showed a significantly higher number of BMP4-positive fibers (37.35 ± 5.63) as compared with muscle of OP patients (9.60 ± 1.57). Unlike BMP4 expression, the number of myostatin-positive fibers in OP patients (33.95 ± 4.10) was significantly higher compared to OA group (13.86 ± 1.68). The ultrastructural analysis of BMP4-positive tissues displayed the presence of a high rate of satellite cells both single or as syncytium giving proof of muscle regeneration capability. DISCUSSION: Our results indicated that sarcopenia and osteoporosis shared an impairment of metabolic activity. Conversely, the molecular mechanisms of OA seem to inhibit the onset of an age-related sarcopenia. CONCLUSION: The characterization of molecular mechanisms underlying the bone-muscle crosstalk could open new therapeutic perspectives in elderly diseases.

Augmentation of tibial plateau fractures with an injectable bone substitute: CERAMENT™. Three year follow-up from a prospective study.

BACKGROUND: Reduction of tibial plateau fractures and maintain a level of well aligned congruent joint is key to a satisfactory clinical outcome and is important for the return to pre-trauma level of activity. Stable internal fixation support early mobility and weight bearing. The augmentation with bone graft substitute is often required to support the fixation to mantain reduction. For these reasons there has been development of novel bone graft substitutes for trauma applications and in particular synthetic materials based on calcium phosphates and/or apatite combined with calcium sulfates. Injectable bone substitutes can optimize the filling of irregular bone defects. The purpose of this study was to assess the potential of a novel injectable bone substitute CERAMENT™|BONE VOID FILLER in supporting the initial reduction and preserving alignment of the joint surface until fracture healing. METHODS: From June 2010 through May 2011 adult patients presenting with acute, closed and unstable tibial plateau fractures which required both grafting and internal fixation, were included in a prospective study with percutaneous or open reduction and internal fixation (ORIF) augmented with an injectable ceramic biphasic bone substitute CERAMENT™|BONE VOID FILLER (BONESUPPORT™, Lund, Sweden) to fill residual voids. Clinical follow up was performed at 1, 3, 9 and 12 months and any subsequent year; including radiographic analysis and Rasmussen system for knee functional grading. RESULTS: Twenty four patients, balanced male-to-female, with a mean age of 47 years, were included and followed with an average of 44 months (range 41-52 months). Both Schatzker and Müller classifications were used and was type II or 41-B3 in 7 patients, type III or 41-B2 in 12 patients, type IV or 41-C1 in 2 patients and type VI or 41-C3 in 3 patients, respectively. The joint alignement was satisfactory and manteined within a range of 2 mm, with an average of 1.18 mm. The mean Rasmussen knee function score was 26.5, with 14 patients having an excellent result and the remaining 10 with a good result. CONCLUSION: It can be concluded that radiological and clinical outcome was satisfactory and obtained in all cases without complications. This injectable novel biphasic hydroxyapatite and calcium sulfate ceramic material is a valuable armamentarium in the treatment of trauma where bone graft is required.

Conservative surgery for the treatment of osteonecrosis of the femoral head: current options.

The prevention of femoral head collapse and the maintenance of hip function would represent a substantial achievement in the treatment of osteonecrosis of the femoral head; however it is difficult to identify appropriate treatment protocols to manage patients with pre-collapse avascular necrosis in order to obtain a successful outcome in joint preserving procedures. Conservative treatments, including pharmacological management and biophysical modalities, are not supported by any evidence and require further investigation. The appropriate therapeutic approach has not been identified. The choice of surgical procedures is based on patient clinical conditions and anatomopathological features; preservation of the femoral head by core decompression may be attempted in younger patients without head collapse. Biological factors, such as bone morphogenetic proteins and bone marrow stem cells, would improve the outcome of core decompression. Another surgical procedure proposed for the treatment of avascular necrosis consists of large vascularized cortical bone grafts, but its use is not yet common due to surgical technical issues. Use of other surgical technique, such as osteotomies, is controversial, since arthroplasty is considered as the first option in case of severe femoral head collapse without previous intervention.

Algodystrophy in major orthopaedic surgery.

Complex Regional Pain Syndrome (CRPS) describes a diversity of painful conditions following trauma, associated with abnormal regulation of blood flow and sweating, trophic changes, and edema of skin. Epidemiology of this disease is not convincing because of the difficulties and inaccuracies in the diagnosis. Several mechanisms are involved in the genesis of CRPS. The higher incidence of CRPS in women over 65 suggests that some changes involving natural and pathologic processes of aging predispose to onset a CRPS. Many features of the orthopaedic management (surgical time, immobilization, surgical incision, fracture osteosynthesis or prosthetic implants) might influence inflammation status in different way. It is mandatory to improve the understanding of both the pathogenesis of CRPS and the conditions that play a decisive role in its genesis. Furthermore it is important to find some biomarkers that allow early diagnosis before the onset of typical clinical signs.

Osseointegration of Fitmore stem in total hip arthroplasty.

Currently, an increasing number of younger patients undergo total hip arthroplasty surgery. This has led to a minimal invasive approach and the use of short, bone preserving, femoral stems. In this study, we sought to evaluate osseointegration of the Fitmore stem (Zimmer, Inc; Warsaw, IN) during the first 12 mo after surgery, which reflects the biological phenomenon of osseointegration with radiographic evaluation and bone densitometry (dual-energy X-ray absorptiometry). We evaluated 33 patients (mean age 62.3) using dual-energy X-ray absorptiometry scan around the stem and X-ray. Moreover, we studied functional recovery using the Harris Hip Score, timed up and go test, and a quality of life form (SF-36), during the follow-up period. At 12 mo, we observed an increased periprosthetic bone mineral density in region of interest 1 (1.7%) and region of interest 7 (8.3%), where there is usually a greater amount of bone resorption. Also Harris Hip Score, timed up and go test, and SF-36 showed an improvement of clinical conditions of all patients. We also used a control group with a standard stem implanted. Because this is the first study correlating osseointegration and clinical outcome of the Fitmore stem, further clinical studies will be necessary to confirm good/positive results and a long stable fixation.

The clinical significance of wrist fracture in osteoporosis.

Wrist fracture is the most common fragility fracture in perimenopausal and young postmenopausal women in USA and Northern Europe. Recent studies based on high-resolution imaging have shown microarchitectural deterioration of trabecular bone even in premenopausal women presenting with a wrist fracture. These fractures increase the risk of subsequent fractures, especially in the first 7 years. So, wrist fracture female patients must be appropriately screened and treated for osteoporosis in order to preserve bone quality and prevent future, more severe, fractures.

Fragility fractures: the clinical pathway.

The clinical management of fragility fracture is simple but complex at the same time. Patients are different from one another, and advancing age increases the prevalence of comorbidities and conditions that can impair bone quality and healing, while increasing the risk of falls and fractures. Keeping in mind some principles and key points can help identify patients at risk, thus following an ideal path for the identification, treatment and prevention of fragility fractures.

Stress fractures in the elderly: different pathogenetic features compared with young patients.

Stress fractures mainly occur in the lower limb as a result of cyclic submaximal stresses. Most commonly affected by this specific type of fractures are young athletes, military or elderly subjects with metabolic bone diseases like osteoporosis. In consideration of the heterogeneity of affected patients is presumable that there are different pathogenic mechanisms. In young person bone tissue, although metabolically intact, is not able to withstand the stresses to which it is chronically subjected, also because of muscle fatigue. This leads to a macrostructural failure and to the development of "fatigue" fractures. Instead, in elderly patients, there are numerous physiological conditions that determine a bone metabolism alteration. This is the main reason for the structural changes in trabecular and cortical bone, which is reflected in reduced biomechanical strength. In addition, muscular situation, such as muscle fiber atrophy, is unable to correctly support bone tissue, leading to the development of insufficiency fractures.

Total hip arthroplasty revision in elderly patients.

In the last years, the number of total hip arthroplasty is increased both in young patients and elderly with a poor bone quality due to extension of surgical indications. According to this trend, also revision surgery showed a growth of its number, especially in elderly patients, because of implant loosening, failed osseointegration of prosthetic components, errors in biomechanical restoration and infections. The aim of this study is to analyze life quality improvement through evaluation of articular functionality and postoperative pain, and to examine osseointegration of implant components with periprosthetic bone. During total hip arthroplasty revision, the orthopedic surgeon often has to face complex cases, especially in elderly patients with a preexisting status of poor bone quality and sarcopenia. In these cases, a correct planning and a surgical procedure well-executed are able to ensure a good outcome that led to pain relief and functional recovery. Furthermore anti-osteoporotic therapy surely represents a useful resource both in primary total hip arthroplasty and in revisions, mainly for elderly patients with a poor bone quality.