The inhibition of neutrophil antibacterial activity by ultra-high molecular weight polyethylene particles.

Following infection, bacterial killing by polymorphonuclear leukocytes (neutrophils) is the main host defense against bacteria. Our hypothesis is that particles of ultra-high molecular weight polyethylene (UHMWP) may impair local neutrophil function and consequently reduce neutrophil bacterial killing. To determine how the in vitro phagocytic-bactericidal activity of neutrophils was affected by exposure to wear particles, tests were run comparing the effects of different particle composition, and different concentrations and sizes of UHMWP particles. There was a significant correlation between the number of particles and the decrease in neutrophil bactericidal activity (p<0.01), and the greatest effect was obtained with a concentration of 10(7) UHMWP/ml. There was a significant decrease in neutrophil bactericidal activity by incubation with particles of 0.1-5 microm (p<0.01), but not with larger size. The results suggest that neutrophil functional defects triggered by the presence of UHMWP particles may potentially contribute to the susceptibility of loose implants to bacterial infections

Hip fracture surgery: Is the pre-operative American Society of Anesthesiologists (ASA) score a predictor of functional outcome?

Background and aims: Many studies have identified specific demographic, social, health or life-style pre-operative indicators of long-term outcome among older hip fracture patients who underwent surgical treatment. The purpose of this study was to determine the predictive value of peri- and intra-operative factors, and more specifically of the pre-operative American Society of Anesthesiologists (ASA) score on functional outcome in these patients. Methods: A questionnaire designed to assess pre-fracture functional and health status was administered to surgically treated hip fracture patients. Post-fracture functional and health status was further ascertained by in-home interview one year after the operation. Among 140 consecutive eligible patients older than 65 years, 10 either refused subsequent interviews or could not be contacted; an additional 16 patients died during the year of follow-up, leaving 114 patients available for this study. Results: The average age of the patients was 82.4 years. Almost two-thirds of them suffered from severe systemic disease, whether or not incapacitating (ASA grades III-IV). Subjects classified in these categories presented more frequently with cardiovascular disorders, were more frequently disoriented, and already had some pre-fracture difficulty with ambulation. The mortality at one year was almost nine times higher in severely impaired patients (grades III-IV) than in healthy or mildly affected patients (grades I-II). Functional outcome and/or ambulatory ability assessed at one year did not reveal any statistically significant difference between the ASA I-II and III-IV groups. The most pronounced difference was noticed for the functional independence measured by the ADL score (p=0.236). Better prognoses were consistently recorded for patients with an intracapsular fracture, for those who were operated within 24 hours, for those treated with a prosthesis as opposed to internal fixation, and for those whose operating time was less than 1½ hours. Conclusions: Although the ASA classification is a good predictor of long-term mortality, the findings of the present investigation do not conclusively associate ASA score with post-operative restoration of mobility and functional independenc

Trends in the treatment of orthopaedic prosthetic infections

The most commonly used therapy for prosthetic joint infection is a two-stage prosthetic exchange separated by 6 weeks of intravenous antibiotic therapy. This often results in long periods of hospitalization, morbidity, severe functional impairment and sometimes increased mortality. Therefore novel and challenging therapeutic approaches have been attempted, particularly in hip prosthetic infection. This includes, whenever possible, according to the type of microorganism, antibacterial susceptibility and clinical presentation (including age and comorbidities): (i) less aggressive surgical techniques (debridement and prosthesis retention, or re-implantation with a single-stage exchange arthroplasty); and (ii) antibiotic combinations active against biofilm-associated bacteria, including rifampicin (particularly with quinolones) with excellent bio-availability which allow prolonged and efficient oral therap

Upper extremity fractures in the elderly: consequences on utilization of rehabilitation care

Background and aims: While hip fractures represent the most dramatic consequence of osteoporosis, fractures of the humerus, forearm and wrist account for one-third of the total incidence of fractures due to osteoporosis in the older population. The aim of this retrospective cohort study was to evaluate rehabilitation care utilization and associated factors in elderly individuals with upper limb fracture. Methods: Over two years, 667 patients 65 years of age or older were studied, who presented to the emergency department either from their private homes or nursing homes with an upper extremity fracture. The following outcome variables were collected: gender; age; residence; location of fracture; treatment; discharge destination; length of hospitalization; length of stay in a rehabilitation facility; and ultimate place of habitation after the event. Results: The most frequent sites of fracture were distal radius (37.2%) and proximal humerus (29.1%). Two-thirds of the patients were treated non-operatively. Inpatient rehabilitation care was necessary for 248 patients (37.2%; length of stay, 46 days). Factors associated with increased care included older age (≥80 years), coming from private home, sustaining two fractures, fractures of the humerus, and operative treatment. Six percent of the patients required permanent nursing home care. Conclusions: Upper extremity fractures in older people often require prolonged hospitalization and therefore account for considerable health care costs. Reasons are more related to advanced age and living conditions than to particular injury or treatmen

Prospective randomised study comparing screw versus helical blade in the treatment of low-energy trochanteric fractures

Purpose: The purpose of this study was to compare femoral head placement, rates of reoperation and cephalic implant cut-out of a screw versus a blade for patients over age 60 with low energy trochanteric fractures (AO/OTA 31-A1, A2, and A3) treated either with sliding hip screw or cephalomedullary nail. Methods: After surgeon selection of either hip screw or nail, hip screw patients were randomised to either a DHS (dynamic hip system screw) or DHS blade (dynamic hip system blade), while nail patients were randomised to either a Gamma3 Trochanteric Nail or a PFNA (proximal femoral nail antirotation). This resulted in a screw group (DHS and Gamma nail), and a blade group (DHS blade and PFNA). Outcome measures included tip-apex distance and zone location of the cephalic implant, as well as reoperation and implant cut-out within the first postoperative year. Results: A total of 335 patients were randomised, 172 to a screw and 163 to a blade. There was no significant difference concerning mean tip-apex distance, percentage of patients with a tip-apex distance >25mm, and patients with a centre-centre position of the cephalic implant. There were 137 patients in the screw group and 132 in the blade group available for follow-up. They did not differ regarding rates of reoperation or cut-out (screw group = 2.9%; blade group = 1.5%). Conclusions: Both a screw and a blade performed equally well in terms of implant placement in the femoral head and outcom

The safety and efficacy of high-dose daptomycin combined with rifampicin for the treatment of Gram-positive osteoarticular infections

Purpose: Treatment of Gram-positive osteoarticular infections requires an adequate surgical approach combined with intensive antimicrobial therapy. The aim of this study was to evaluate the safety and efficacy of a combined regimen of high-dose daptomycin and rifampicin, in patients with various types of Gram-positive osteoarticular infections. Methods: This single centre, non-comparative, prospective study evaluated the safety and efficacy of a combined regimen of intravenous daptomycin (8mg/kg/day) and oral rifampicin (600mg/day) in patients with Gram-positive osteoarticular infections, with a minimal follow-up of oneyear. Creatine phosphokinase, transaminases, bilirubinaemia, and serum creatinine, were measured at baseline and regular intervals. Results: The median daily doses of daptomycin and rifampicin, administered for a median duration of 21 (range, 10-122) days to 16 patients (median age, 63.5years; 11 males, five females) presenting with staphylococcal (n = 15) or streptococcal (n = 1) osteoarticular infections, were 8.15 (range, 6.6-8.9) mg/kg/day and 600 (range, 600-900) mg/day, respectively. The combined regimen of daptomycin and rifampicin was well tolerated by all except one patient, without requiring treatment adjustment or discontinuation. One patient developed allergic responses probably due to rifampicin after 42days. Fifteen (94%) patients showed favourable clinical and microbiological outcomes. Conclusions: The combined regimen of high-dose daptomycin and rifampicin was well tolerated and may provide a useful alternative to standard glycopeptide therapy for Gram-positive osteoarticular infection

Prognosis of Functional Recovery 1 Year After Hip Fracture: Typical Patient Profiles Through Cluster Analysis

Background. Many investigators have identified distinct medical, demographic and psychosocial prefracture conditions that influence the functional outcome of patients surgically treated for a fracture of the hip. However, to design efficient intervention care programs addressing the needs of these patients, at optimal economic and social costs, more information is required on the typical combinations of prognostic determinants actually encountered. Methods. Data on specific descriptors of the prefracture status and on mobility and functioning 1 year after surgical intervention were collected by interview from 253 consecutive patients hospitalized for a fracture of the proximal femur. Cluster analysis was used to form homogeneous groups of patients with similar profiles in terms of the 13 predictive variables and the 7 outcome variables significantly interrelated. The modeling procedure generated four clusters of patients with a typical profile sharply contrasted by their structure. Results. Subjects of two clusters could walk without difficulty and were functionally independent prior to their hip fracture. One year later, however, mobility and functioning were only fully recovered by the members of one cluster. The majority of predictors were of less favorable prognostic value for the members of the second cluster. The other two clusters regrouped patients with impaired prefracture mobility that were either unaltered or even aggravated 1 year later. Conclusions. Cluster analysis identified typical profiles of elderly hip fracture patients. Close scrutiny of their respective global structure, in terms of combined prognostic determinants and outcomes, may help to develop specific management strategies that are more efficiently adapted to these different groups of patient