Painful knee prosthesis: surgical approach

There are many conditions that may be responsible of a painful knee prosthesis. The possible causes are not always easily diagnosed. Common causes of prosthetic failure, such as aseptic loosening, infection, instability, progressive patellar arthropathy and recurrent synovitis are associated with clearly defined radiographic and/or clinical evidence. Prosthetic infection should always be considered first until any other cause has been demonstrated. In the presence of an infected prosthesis we carry out a two-step revision. Aseptic loosening needs implant revision more often with increasing prosthesis stability. Varus-valgus, anteroposterior, global and patello-femoral instability are failures often due to technical errors; superstabilized or constrained implants are needed depending on the instability entity

Surgical strategies for high-energy fractures in patients with osteoporosis

The most obvious clinical pattern of osteoporosis is represented by the so-called low energy fractures. These are slight trauma bone lesions that would not occur in a subject with normal bone mineral density (BMD). The most frequently affected sites of this type of fracture are the last dorsal and lumbar vertebrae, the proximal femur, humerus, and the distal radius. These fractures are a challenge for the orthopedic surgeons because they occur on an altered bone, with decreased load resistance, reduced elasticity and decreased ability to absorb mechanical stresses. This physio-pathological pattern results in lower stability of the hardware, lower screws purchase, less resistance to bone-prosthesis interface, lower quality of the healing process. The problem becomes more complex when high-energy trauma occur in osteoporotic bone with fractures in nontypical locations such as distal femur, tibial plate, tibial malleolus, elbow or peri-phrostetic fractures after Total Knee or Hip Replacement. The surgical approach to these fractures aims to use devices that assure greater bone-implant stability and a great distribution of stresses by reducing the forces acting on the bone-implant interface. It is possible to use scaffolds such as bioactive cement and porous coating surfaces to increase the hardware purchase and homologous/autologous transplantation, post-operative pharmacological implementation and growth factors to stimulate potential repair of fractures. The use of locking plates allows converting the sliding forces, which the traditional plates generated, into compression forces to increase the stability of the system. There are also versatile hardware with dynamic angular stability screws that can be freely oriented in space unlike conventional plates where the direction of the screw is dictated by the placement of the plate. The philosophy of minimal invasive surgery is well represented by the use of intramedullary nails, which can stabilize the fracture from the inside of the bone marrow. This characteristic ensures a load distribution within the bone especially in meta-diaphysis areas, which are most affected by typical reduction of bone quality of osteoporosis. In the elderly, the total joint replacement is also indicated in cases of peri-articular fractures in which there is a high risk of bone fragments necrosis. Such fractures can be treated with a prosthetic implant to ensure immediate joint stability and thus allow an early recovery of the range of motion and the function of the affected limb. Treatment of peri-prosthetic fractures is another important chapter in surgery of traumatic fractures in osteoporosis as we find more and more frequent patients who have a prosthetic implant and who undergo a trauma that causes a peri-implant fracture. In this case, the evaluation of the implant's stability to the bone-prosthesis interface is crucial to decide whether to perform a synthesis with angular stability, nails and/or cerclage wires, or to perform a revision. In all cases, treatment of traumatic fractures in osteoporosis requires a multidimensional evaluation of the problem, as it is not only the type of fracture and site that can be considered, but also the bone quality by carefully evaluating the patient's functional and metabolic state and its comorbidity. It is a surgery that requires specific implants and devices that must be carried out by experienced hands

Atypical femur fractures

Already from the late 1970s, some fractures of the subtrochanteric and diaphyseal region of the femur were defined "atypical" and described as "fatigue" fractures. In 2005, Odvina reported an unusual type of femoral fracture after the administration of alendronate as a result of a severely repressed bone turnover and Lenart defined femoral fractures occurring on the subtrocanteric or diaphyseal region in post-menopause women after alendronate therapy as "atypical" (AFFs). Hence the hypothesis that these fractures could be associated with the use of bisphosphonates (BP). Even with a "normal" dose of BP, the risk of fracture is highest if therapy lasts more than 5 years, although cases have recently been reported with short-term therapies. However, many of the studies on this association did not consider the radiographic patterns and the atypical or typical radiographic definition did not evaluate the BP doses used and patient compliance; they just state if there was an association or not, and this had led to an underestimation of the real incidence of these fractures. It is the latest revision of the diagnostic criteria made in 2013 by the American Society for Bone and Mineral Research (ASBMR) Task Force to determine that to be defined as AFF, a fracture localized along the femoral diaphysis just distal from the small trochanter to just proximal to the supracondylar region must have certain clinical and radiographic patterns. They also defined exclusion and minor criteria. In general, incidence is still low. Considering the incidence of all femoral fractures of about 460/100,000 people-year, the sub-trochanteric ones represent 7 to 10% of these, and atypical ones are even rarer: 32 per million people-year and 5, 9 per 100,000 person-years in a retrospective study from 1996 to 2009. Morbidity and mortality are similar to neck or intertrochanteric femoral fractures. However, AFF was also found in patients who had never used BP, so BP therapy could not be the only risk factor. Among them, recent attention has been given to hypoposphatasia, picnodisostosis with mutant catepsin gene, osteopetrosis, tumors, use of glucocorticoids (GC), high body mass index (BMI) and use of proton pump inhibitors (PPI). About pathogenesis it seems that the accumulation of microlesions, the increase of mineralization with reduced heterogeneity of mineralization, accumulation of Advanced Glycation End-products (AGEs), reduced vascularization and reduced antiangiogenic effects, alterations of normal collagen reticulation and maturation variations of crosslinks of collagen are all factors involved. Histological studies have demonstrated how these stress fractures occur: at the fracture site there are thin cracks that even micro-movements can distort and bring to their enlargement. In presence of predisposing conditions (femoral conformation, hypophosphatasia, use of GC...) in BP patients, these cracks are trapped in free mineral deposits at the site of the fracture, particularly at intracortical level and act longer by suppressing just in that site where the remodeling processes are essential to healing. Initial alteration occurs precisely on the lateral cortex, which is subjected to increased stress in the subtrochanteric and diaphyseal region, causing a femur bending. This observation has led to studies that have shown how femoral conformation plays a role in determining an increased risk of AFF. With a same BP therapy duration, for conformation characteristics, more is the lateral curvature of the femur and greater the knee valgus and more frequent are the AFFs; these features are more common in some breeds (Asiatic). Recently AFF case reports have also been published with denosumab, a monoclonal antibody that similarly to BP has an anti-resorptive effect. Some Authors and the ASBMR themselves have outlined guidelines for AFF diagnosis and management. Following patients who are taking BP therapy with DEXA is useful: evidence of certain pre-lesions to DEXA and the presence of prodromal symptoms are strong predictors of a subsequent fracture. Also useful is the dosage and monitoring of biochemical markers of bone remodeling. With regard to surgical strategy, the use of an intramedullary nail is the best treatment. In cases of particularly curved femur it is more appropriate to use angular stability plates because in the case of incomplete fracture the use of a nail may turn it into complete and because even in the case of complete fractures, the risk of non-union is higher. To date, even stopping of BP alone in the AFF suspect and the use of teriparatide as supportive drug therapy are two key elements to enable proper AFF healing

Hip arthrosis and surgical intervention: what and when?

Osteoarthritis of the hip is a common pathology and involves forms of disability and need for treatments that affect the quality of life of patients and their families, and in general of the whole society. It should be considered as such degenerative joint disease is increasing as the increase in life expectancy and musculoskeletal trauma, the latter responsible for secondary forms of osteoarthritis. The treatment of osteoarthritis of the hip has changed a lot over the years, since the earlier diagnosis and, before, with prevention through proper lifestyle. More in-depth knowledge of the biology of the tissues involved, first of all hyaline cartilage, has lead to non-surgical treatments such as infiltration with hyaluronic acid (viscosupplementation) and autologous growth factors derived from platelets (platelet rich plasma). Surgical therapy with prosthetic replacement is finally a choice to share with the patient based on pain and functional limitation, bearing in mind always the best technology and tribology and the possibility of less invasive surgical access, while recognizing that there are not still eternal prosthesis. Of particular importance then is the age of the patient. There are also other types of surgery (hip arthroscopy, forage) for other pathologies of the hip which can be resolutive, or, in a sense, can delay the arrival to the prosthetic replacement. We will discuss below the decision-making process that leads the surgeon with the patient to the surgery optio

Impact on Mobility and Environmental Data of COVID-19 Lockdown on Florence Area

According to the changed operative conditions due to lockdown and successive reopening a number of facts can be analysed. The main effects have been detected on: mobility, environment, social media and people flows. While in this first report only mobility, transport and environment are reported. The analysis performed identified a strong reduction of the mobility and transport activities, and in the pollutants. The mobility reduction has been assessed to be quite coherent with respect to what has been described by Google Global mobility report. On the other hand, in this paper a number of additional aspects have been put in evidence providing detailed aspects on mobility and parking that allowed us to better analyze the impact of the reopening on an eventual revamping of the infection. To this end, the collected data from the field have been compared from those of google and some considerations with respect to the Imperial college Report 20 have been derived. For the pollutant aspects, a relevant reduction on most of them has been measured and rationales are reported.</jats:p

How COVID-19 Lockdown Impacted on Mobility and Environmental data

According to the COVID-19 lockdown and successive reopening a number of facts can be analysed. The main effects have been detected on: mobility and environment, and specifically on traffic, environmental data and parking. The mobility reduction has been assessed to be quite coherent with respect to what has been described by Google Global mobility report. On the other hand, in this paper a number of additional aspects have been put in evidence providing detailed aspects on mobility and parking that allowed us to better analyse the impact of the reopening on an eventual revamping of the infection, also taking into account of the Rt index. To this end, the collected data from the field have been compared from those of Google and some considerations with respect to the Imperial college Report 20 have been derived. For the pollutant aspects, a relevant reduction on most of them has been measured and rationales are reported. The solution has exploited the Snap4City IOT smart city infrastructure and data collector and Dashboard in place in Tuscany.</jats:p