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Purpose Synovial fluid cultures of periprosthetic joint infections (PJI) may be limited by bacteria living in the fluids as biofilm-aggregates. The antibiofilm pre-treatment of synovial fluids with dithiotreitol (DTT) could improve bacterial counts and microbiological early stage diagnosis in patients with suspected PJI. Methods Synovial fluids collected from 57 subjects, affected by painful total hip or knee replacement, were divided into two aliquots, one pre-treated with DTT and one with normal saline. All samples were plated for microbial counts. Sensitivity of cultural examination and bacterial counts of pre-treated and control samples were then calculated and statistically compared. Results Dithiothreitol pre-treatment led to a higher number of positive samples, compared to controls (27 vs 19), leading to a statistically significant increase in the sensitivity of the microbiological count examination from 54.3 to 77.1% and in colony-forming units count from 1884 ± 2.129 CFU/mL with saline pre-treatment to 20.442 ± 19.270 with DTT pre-treatment (P = 0.02). Conclusions To our knowledge, this is the first report showing the ability of a chemical antibiofilm pre-treatment to increase the sensitivity of microbiological examination in the synovial fluid of patients with peri-prosthetic joint infection. If confirmed by larger studies, this finding may have a significant impact on routine microbiological procedures applied to synovial fluids and brings further support to the key role of bacteria living in biofilm-formed aggregates in joint infections.

Background Ankle periprosthetic joint infections are rising in number, but an evidence-based gold standard treatment has not been defined yet. Methods We made a systematic review about the operative treatment of infections following total ankle arthroplasty. Proportional meta-analysis was used to summarize effects of the surgical techniques included. Primary outcome of this study was infection eradication, followed by complications, re-interventions, amputation rates and functions. Results We included six studies(113 patients) reporting 6 types of surgical interventions, mostly irrigation and debridement (35.4%) and two-stage revisions (24.8%). No differences among all analyzed techniques were found in the infection eradication outcome as well as in the secondary outcomes. Patients receiving a permanent spacer are most likely to end up with amputation. Conclusions Literature dealing with infections after total ankle replacement is currently composed by few low-quality articles. The overlapping of confidence intervals related to all analyzed interventions showed no superiority of either technique. Level of evidence III.

The aim of this study was to investigate the hypothesis that a two-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, may provide better infection cure rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic hip infection. In this case-control study, 27 patients, treated with a two-stage procedure, using cementless implants coated with an antibiotic-loaded hydrogel (DAC®, “Defensive Antibacterial Coating”), were compared with 27 matched controls, treated with a two-stage cementless revision procedure, without the coating. At a mean follow-up of 2.7 (minimum 2.1–maximum 3.5) years, no evidence of infection, implant loosening, or adverse events were observed in the DAC-treated group, compared to four cases of infection recurrence in the control group. Although in a relatively limited series of patients our data show that cementless two-stage hip revision, performed with an antibacterial hydrogel coating, may provide better infection control than two-stage without the coating, with reduced hospitalization time, these findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections.

Thirty years after its description by Masquelet in 1986, this is the first systematic review aiming to critically evaluate the 'induced membrane technique' effectiveness in achieving bone union in children. Only six papers fulfilled our inclusion criteria (54 patients). The relatively small number of reported cases did not allow a formal meta-analysis. The tibia was the most involved bone. Most frequent aetiologies were congenital pseudoarthrosis and tumour resections. Although effective in achieving bone healing in ∼91% of the patients (bone defects ≤24 cm long), the induced membrane technique was associated with a high rate of complications (54% of patients). Level of evidence IV.

The treatment of chronic osteomyelitis often includes surgical debridement and filling the resultant void with antibiotic-loaded polymethylmethacrylate cement, bone grafts or bone substitutes. Recently, the use of bioactive glass to treat bone defects in infections has been reported in a limited series of patients. However, no direct comparison between this biomaterial and antibiotic-loaded bone substitute has been performed. In this retrospective study, we compared the safety and efficacy of surgical debridement and local application of the bioactive glass S53P4 in a series of 27 patients affected by chronic osteomyelitis of the long bones (Group A) with two other series, treated respectively with an antibiotic-loaded hydroxyapatite and calcium sulphate compound (Group B; n = 27) or a mixture of tricalcium phosphate and an antibiotic-loaded demineralised bone matrix (Group C; n = 22). Systemic antibiotics were also used in all groups. After comparable periods of follow-up, the control of infection was similar in the three groups. In particular, 25 out of 27 (92.6%) patients of Group A, 24 out of 27 (88.9%) in Group B and 19 out of 22 (86.3%) in Group C showed no infection recurrence at means of 21.8 (12 to 36), 22.1 (12 to 36) and 21.5 (12 to 36) months follow-up, respectively, while Group A showed a reduced wound complication rate. Our results show that patients treated with a bioactive glass without local antibiotics achieved similar eradication of infection and less drainage than those treated with two different antibiotic-loaded calcium-based bone substitutes. Cite this article: Bone Joint J 2014; 96-B:845–50.

Diagnosis of prosthetic joint infections (PJIs) remains a challenge for microbiologists, despite new techniques for bacteria isolation have been developed in recent years. A widely recognized standard method has not yet been indicated mainly because of limitations due difficult procedures and need of dedicated instrumentation. We evaluated the ability of a sulfhydryl compound routinely used in microbiology laboratories, dithiothreitol (DTT), to dislodge bacteria from biofilm, keeping them alive and cultivable for identification and antibiotic susceptibility testing. We compared DTT treatment against sonication of prosthesis and culture of periprosthetic tissues, in order to establish if it could be introduced in routine microbiological diagnosis of PJIs. The study was conducted on 76 patients, 34 with aseptic loosening of their prosthesis and 42 who were diagnosed for PJI. DTT treatment gave results similar to sonication in terms of bacterial yielding. Sonication provided higher sensitivity (71.4%) and specificity (94.1%) respect to periprosthetic tissue culture, while DTT showed the same specificity of sonication but a better sensitivity (85.7%), especially when the causative microorganism was Staphylococcus epidermidis. In conclusion, we demonstrated that DTT could be used for PJIs diagnosis, thanks to its ease of use and its high sensitivity and specificity.

Biofilms have a tremendous impact on industrial machines working in moist environments, while in biological systems their effect is further complicated by the host's response.Implant-related infections are a complex process, starting with bacterial adhesion and biofilm formation, followed by the variable interaction between host, implant, microorganisms and their by-products. Depending on the balance of these factors, different clinical presentations are observed, which may eventually, at times, shift from one into the other.-"Implant malfunction" displays only mild clinical signs/symptoms - light pain and/or slight soft tissue contracture or functional impairment - with negative infection/inflammatory markers; it requires prolonged cultures, antibiofilm and eventually genomic investigations for pathogen detection;-"Low-grade infection" features recurrent or persistent pain and/or soft tissue contracture with various functional impairment and mixed positive/negative markers of infection/inflammation; pathogen identification requires prolonged cultures and antibiofilm techniques;-"High-grade infection" displays classical signs/symptoms of infection/inflammation with positive tests; pathogen identification is often possible with traditional microbiological techniques, but is better achieved with prolonged cultures and antibiofilm processing.Understanding biofilms-related clinical presentations is crucial for physicians, to implement the best diagnostic and therapeutic measures, and for regulatory bodies, to define the evaluation process of technologies aimed at reducing implants' malfunctions and infections, like anti-adhesive and antibiofilm coatings, that should be regulated as (part of) medical devices, requiring a suitable post-marketing surveillance.Only an effective antibiofilm-targeted approach from all players will hopefully allow the medical community to mitigate the current unacceptable social and economical burden of implant-related infections and malfunctions.

Introduction and methods Contaminated dressings are particularly suitable for growth of microorganisms and a well-known source of bacterial spreading in the hospital environment. This study evaluates the bacterial contamination of white coats and surgical gowns and drapes treated with a novel antibacterial finishing technology of hospital textiles. Bacterial contamination rates of untreated white coats and surgical gowns and drapes were compared to treated textiles. In vitro determination of antibacterial activity against reference bacterial strains and clinical isolates was performed according to the European guideline EN ISO 20645. Efficacy of the treatment was verified in clinical setting by comparing the amount of bacteria isolated from treated and untreated textiles used for clinical and surgical activities.

Purpose. Chronic low back pain (LBP) is often characterized by both nociceptive and neuropathic components. While various monotherapies have been reported of only limited efficacy, combining drugs with different mechanisms of action and targets appears a rational approach. Aim of this systematic review is to assess the efficacy and safety of different combined pharmacological treatments, compared to monotherapy or placebo, for the pharmacological treatment of chronic LBP.Methods. Published papers, written or abstracted in English from 1990 through 2011, comparing combined pharmacological treatments of chronic LBP to monotherapy or placebo were reviewed.Results. Six articles met the inclusion criteria. Pregabalin combined with celecoxib or opioids was shown to be more effective than either monotherapy. Oxycodone-paracetamol versus previous treatments and tramadol-paracetamol versus placebo were also reported as effective, while morphine-nortriptyline did not show any benefit over any single agent.Conclusions. In spite of theoretical advantages of combined pharmacological treatments of chronic LBP, clinical studies are remarkably few. Available data show that combined therapy, including antinociceptive and antineuropathic agents is more effective than monotherapy, with similar side effects.

Two-stage revision is the most widely accepted and performed intervention for chronically infected hip prosthesis and different interim spacers have been proposed. In recent years, antibiotic-loaded preformed spacers have become available on the market. The aim of this retrospective study was to assess the long-term results of two-stage revision with preformed spacers and uncemented hip prosthesis for the treatment of septic hip prosthesis.From 2000 to 2010, 183 consecutive patients underwent two-stage revision of septic hip prosthesis, with a same protocol, including preformed antibiotic-loaded cement spacer and a cementless modular hip revision prosthesis and four to six weeks antibiotic administration. Clinical and radiologic assessment at a minimum follow-up of two years was performed.At a minimum two years follow-up, 10 patients (5.4%) had had an infection recurrence, four (2.2%) an aseptic loosening and four more required partial revision of the modular components of the prosthesis, because of hip instability/dislocation; 21 patients died or were lost to follow-up. Considering all the reasons for revision, survivorship at eleven years was 93.9%. Harris Hip Score improved from 29.1 ± 14.6 pre-operatively to 41.1 ± 15.9 after spacer implant and 81.7 ± 17.6 after hip revision. The main complications after spacer implant included: spacer dislocation (16.4%), intra-operative femoral fractures (2.7%), and thromboembolism (2.1%). Complications after hip revision were: instability/dislocation (4,3%), intra-operative femoral fractures (1.6%), and thromboembolism (3.3%).Two-stage revision of septic hip prosthesis with preformed antibiotic-loaded spacers and cementless hip prosthesis provides satisfactory long-term results, with reduced complications.

Background Isolated reports indicate the efficacy of infrared thermography for monitoring wound healing and septic complications, but no long-term analysis has ever been performed on this, and there are no data on the telethermographic patterns of surgical site healing after uncomplicated total hip prosthesis and after knee prosthesis. Materials and methods In this prospective, observational, nonrandomized cohort study, two groups with forty consecutive patients each, who were operated on respectively for total hip and for total knee replacements, underwent telethermographic examination of the operated and contralateral joints prior to and at fixed intervals for up to 1 year after uncomplicated surgery. A digital, portable telethermocamera and dedicated software were used for data acquisition and processing. Results No thermographic difference was observed preoperatively between the affected side and the contralateral side in both groups. After the intervention, a steep increase in the temperature of the operated joint was recorded after total hip replacement and after knee replacement, with a peak mean differential temperature measured three days postoperatively between the operated and unoperated joint of 3.1 ± 0.8°C after total hip replacement, and 3.4 ± 0.7°C after total knee replacement. Thereafter, the mean differential temperature declined slowly to 0.7 ± 1.1°C and to 0.5 ± 1.3°C at 60 days, and to 0.0 ± 1.0°C and −0.1 ± 1.1°C 90 days post-operatively, respectively. No further changes were observed for up to 1 year after surgery. Results were similar when comparing the average telethermographic values of an elliptical area where the main axis corresponded to the surgical wound. Conclusions The surgical sites after uncomplicated total hip or total knee replacement show similar telethermographic patterns for up to 1 year from surgery, and can easily be monitored using a portable, digital, telethermocamera.

Background The few available studies directly comparing aseptic and septic joint revision surgery report conflicting results. We investigated whether two-stage revision of septic hip prosthesis with a preformed antibiotic-loaded spacer and an uncemented prosthesis provides hip function and quality of life similar to those provided by aseptic revision surgery in the medium term, as well as the associated direct hospital costs. Materials and methods We prospectively evaluated the hip function (Harris hip score) and quality of life (WOMAC and SF-12 scores) of 80 patients who underwent one-stage revision for aseptic loosening (Group A, 40 patients) or two-stage revision for septic total hip prostheses (Group S, 40 patients). Patients were matched for gender, age, and bone loss. A preformed antibiotic-loaded cement spacer was used for two-stage revision, and uncemented modular prostheses were implanted at revision in both groups. The minimum follow-up was 2 years (average 4 years; range 2–6 years). Results We found no difference in infection recurrence or aseptic loosening rate in the two groups. Average Harris hip score increased similarly in both groups: from 19.1 to 74.0 in Group A versus 15.0–71.2 in Group S. Patient-reported quality-of-life questionnaires (SF-12 and WOMAC) at last follow-up were similar postoperatively, but the complication rate for Group S was twice that of Group A (20.8 versus 10%). Mean overall hospital-related costs of two-stage procedures were 2.2 times greater than those for aseptic revisions. Conclusions Two-stage revision for infected hip prostheses, using a preformed antibiotic-loaded cement spacer and uncemented revision prosthesis, offers a success rate comparable to noninfected revisions in the medium term but is associated with a higher complication rate and costs.

Biofilms have a tremendous impact on industrial machines working in moist environments, while in biological systems their effect is further complicated by the host’s response.

According to current knowledge, the most critical pathogenic event in the development of implant-related infection is probably biofilm formation, which starts immediately after bacterial adhesion on implanted devices, leading to their irreversible colonization.

Implanted biomaterials play a key role in current success of orthopedic and trauma surgery. However, implant-related infections remain among the leading reasons for failure with high economical and social associated costs. According to the current knowledge, probably the most critical pathogenic event in the development of implant-related infection is biofilm formation, which starts immediately after bacterial adhesion on an implant and effectively protects the microorganisms from the immune system and systemic antibiotics. A rationale, modern prevention of biomaterial-associated infections should then specifically focus on inhibition of both bacterial adhesion and biofilm formation. Nonetheless, currently available prophylactic measures, although partially effective in reducing surgical site infections, are not based on the pathogenesis of biofilm-related infections and unacceptable high rates of septic complications, especially in high-risk patients and procedures, are still reported. In the last decade, several studies have investigated the ability of implant surface modifications to minimize bacterial adhesion, inhibit biofilm formation, and provide effective bacterial killing to protect implanted biomaterials, even if there still is a great discrepancy between proposed and clinically implemented strategies and a lack of a common language to evaluate them. To move a step forward towards a more systematic approach in this promising but complicated field, here we provide a detailed overview and an original classification of the various technologies under study or already in the market. We may distinguish the following: 1. Passive surface finishing/modification (PSM): passive coatings that do not release bactericidal agents to the surrounding tissues, but are aimed at preventing or reducing bacterial adhesion through surface chemistry and/or structure modifications; 2. Active surface finishing/modification (ASM): active coatings that feature pharmacologically active pre-incorporated bactericidal agents; and 3. Local carriers or coatings (LCC): local antibacterial carriers or coatings, biodegradable or not, applied at the time of the surgical procedure, immediately prior or at the same time of the implant and around it. Classifying different technologies may be useful in order to better compare different solutions, to improve the design of validation tests and, hopefully, to improve and speed up the regulatory process in this rapidly evolving field.

Summary of the BION Shoulder Subluxation and Knee Osteoarthritis Studies. Subacute Shoulder Subluxation Knee OsteoarthritisLocation Kingston, Canada Milan, ItalyDesign Randomized, cross-over Longitudinal, repeated measuresBaseline No Yes, 12 weeksStimulation period 6 weeks 12 weeksOff-stim. period 6 weeks NoStimulation frequency 5 Hz 2 HzAssessment Subluxation, active/passive ROM, strength, arm function, VAS pain, muscle thickness (ultrasound).WOMAC, Knee Function, VAS pain,muscle cross-sectional area (MRI).# subjects (July 2002) 10 (5 TES; 5 control initially) 5# control subjects 3 (out of 5, above) N/Acrossed-over to TES# total TES 8 (5 initial; 3 cross-over from control) 5# noncompliant TES 3 (out of 8, above) 0Final subject distribution 5 compliant TES; 3 noncompliant N/ATES; 5 control# BIONs implanted (July 2002)17 (8 TES subjects—one has two BIONs in the supraspinatus because of technical failure)8 (subjects 1–3 have 2 BIONs each; subjects 4–5 have one BION each) Fig. 3. Top: BION being removed from Subject 1 in theshoulder subluxation study (trapezius). Bottom: histologicsection of excised muscle (left: muscle cells; right: scar tissuearound device).

Irrigation and debridement (ID) has been described as a possible option to eradicate early postoperative periprosthetic hip and knee infections, as well as late, acute, and hematogenous ones. Still, the literature fails to uniquely assess the effectiveness of this procedure and often provides conflicting evidence. To reconcile this difference, a systematic review of the available literature from 1970 to 2013 was undertaken. Fifteen articles, for a total of 796 patients, met the inclusion criteria; the average success rate was 44.9 and 52% after a single or repeated ID procedures, respectively, at an average of 4 years follow-up. Despite the methodological differences and the heterogeneity of the material reviewed, this study demonstrates that this procedure only attains a relatively low success rate of infection eradication, depending on when patients are selected for surgical intervention according to the timeframe of their symptoms.

The aim of the present study was to assess the efficacy of a thrombin-based topical haemostatic in reducing blood requirements after total knee replacement (TKR) revision surgery. This prospective, randomized, controlled study was designed to evaluate the haemostatic efficacy and safety of a thrombin-based topical haemostatic (Floseal) versus standard treatment in patients receiving total knee revision arthroplasty. The decrease in haemoglobin values postsurgery and the blood units transfused were recorded. The decision to transfuse was made by a surgeon blinded to the patient’s group allocation. Forty-eight patients were enroled in the study; twenty-four patients each were randomized to the treatment and control groups, respectively. The median decrease in haemoglobin concentration on the first postoperative day was 2.2 g/dL in the treatment group and 2.7 g/dL in the control group. A significant reduction in units of blood transfused was also observed in the treatment group compared with the control group [1.1 ± 1.13 (range 0–4) vs. 1.9 ± 1.41 (range 0–5) blood units; P = 0.04]. No major treatment-related adverse events were recorded in the study. This study shows that a thrombin-based topical haemostatic reduces the need for blood transfusion in TKR revision surgery. A thrombin-based topical haemostatic agent can be an appropriate solution to enhance haemostasis and vessel sealing at the operative site in TKR revision surgery, in order to reduce the need for blood transfusion after surgery. II.

Our purpose was to evaluate long-term results of two-stage cementless intramedullary nailing without achieving bone-to-bone fusion for treating chronically infected total knee arthroplasty (TKA).Thirty-eight patients treated according to the same protocol were retrospectively evaluated for clinical, functional, laboratory and radiological outcomes.Spacer exchange was necessary for infection persistence in one case. At a minimum two year follow-up, 34 patients (89.5%) showed no infection recurrence; among these 34 patients, 29 (85.3%) reported no or moderate pain [visual analogue scale (VAS) ≤3]; mild to moderate handicap (Lequesne Algofunctional Index 7.5) was observed in 18 patients (52.9%). No patient underwent revision for aseptic loosening, and no nail breakage was observed.Two-stage cementless intramedullary nailing without achieving bone-to-bone fusion is a viable option for treating chronically infected TKA in selected, complex cases.

Diagnosis of prosthetic joint infections (PJIs) remains a challenge for microbiologists, despite new techniques for bacteria isolation have been developed in recent years. A widely recognized standard method has not yet been indicated mainly because of limitations due difficult procedures and need of dedicated instrumentation. We evaluated the ability of a sulfhydryl compound routinely used in microbiology laboratories, dithiothreitol (DTT), to dislodge bacteria from biofilm, keeping them alive and cultivable for identification and antibiotic susceptibility testing. We compared DTT treatment against sonication of prosthesis and culture of periprosthetic tissues, in order to establish if it could be introduced in routine microbiological diagnosis of PJIs. The study was conducted on 76 patients, 34 with aseptic loosening of their prosthesis and 42 who were diagnosed for PJI. DTT treatment gave results similar to sonication in terms of bacterial yielding. Sonication provided higher sensitivity (71.4%) and specificity (94.1%) respect to periprosthetic tissue culture, while DTT showed the same specificity of sonication but a better sensitivity (85.7%), especially when the causative microorganism was Staphylococcus epidermidis. In conclusion, we demonstrated that DTT could be used for PJIs diagnosis, thanks to its ease of use and its high sensitivity and specificity.

BackgroundOsteopetrosis is a rare, inherited, bone disorder, characterized by osteosclerosis, obliteration of the medullary cavity and calcified cartilage. The autosomal dominant form is compatible with a normal life span, although fractures often result from minimal trauma, due to the pathologic nature of bone. Osteomyelitis is common in patients with osteopetrosis because of a reduced resistance to infection, attributed to the lack of marrow vascularity and impairment of white cell function. Only one case of osteomyelitis of the proximal third of the femur has been previously reported, treated with several repeated debridements and finally with femoral head resection. Here we present for the first time a case of a staged implant of a cementless total hip prosthesis for the treatment of a septic hip in femoral neck nonunion in osteopetrosis.Case presentationA 36-years-old woman, affected by autosomal dominant osteopetrosis was referred to our department because of a septic hip arthritis associated with femoral neck septic non-union, with draining fistulas. The infection occurred early after a plate osteosynthesis for a closed perthrocanteric fracture of the femur and persisted in spite of osteosynthesis removal, surgical debridement and external fixation. In our hospital the patient underwent accurate debridement, femoral head and greater trochanter resection, preparation of the diaphyseal intramedullary canal and implant of an antibiotic-loaded cement spacer. The spacer was exchanged after one month, due to infection recurrence and four months later, a cementless total hip arthroplasty was implanted, with no clinical and laboratory signs of infection recurrence at two years follow-up.ConclusionsIn case of hip septic arthritis and proximal femur septic non-union, femoral head resection may not be the only option available and staged total hip arthroplasty can be considered.

Debridement and irrigation has been proposed as a salvage procedure for early post-operative and late acute haematogenous periprosthetic hip and knee infections, however the effective ability of this procedure to avoid recurrent infection is still debated.In this systematic review of the literature we reviewed full-text papers published from 1970 through 2011, that reported the success rate of infection eradication after debridement and irrigation with prosthesis retention for the treatment of early septic complications (within six weeks from surgery) or late acute haematogenous infections after hip or knee prosthesis. In all, 14 original articles, reporting the results of 710 patients were retrieved. The average success rate has been, respectively, 45.9% and 52% after a single or repeated debridement and irrigation procedures, at a mean follow-up of 53.3 months.The methodological limitations of this study and the heterogeneous material in the reviewed papers notwithstanding, this systematic review shows that debridement and irrigation procedure is associated with a rather poor outcome, even in a population of patients selected on the basis of symptoms’ duration and patients should be adequately informed prior to undergo this salvage procedure.

The best method for treating chronic periprosthetic knee infection remains controversial. Randomized, comparative studies on treatment modalities are lacking. This systematic review of the literature compares the infection eradication rate after two-stage versus one-stage revision and static versus articulating spacers in two-stage procedures.We reviewed full-text papers and those with an abstract in English published from 1966 through 2011 that reported the success rate of infection eradication after one-stage or two-stage revision with two different types of spacers.In all, 6 original articles reporting the results after one-stage knee exchange arthoplasty (n = 204) and 38 papers reporting on two-stage revision (n = 1,421) were reviewed. The average success rate in the eradication of infection was 89.8% after a two-stage revision and 81.9% after a one-stage procedure at a mean follow-up of 44.7 and 40.7 months, respectively. The average infection eradication rate after a two-stage procedure was slightly, although significantly, higher when an articulating spacer rather than a static spacer was used (91.2 versus 87%).The methodological limitations of this study and the heterogeneous material in the studies reviewed notwithstanding, this systematic review shows that, on average, a two-stage procedure is associated with a higher rate of eradication of infection than one-stage revision for septic knee prosthesis and that articulating spacers are associated with a lower recurrence of infection than static spacers at a comparable mean duration of follow-up.IV.

While diagnosing infection of a joint prosthesis often requires a multi-modal approach, evaluation of combined multiple diagnostics is still a rather subjective process. Based on the known sensitivity and specificity of commonly performed tests for joint prosthesis infection, we developed the Combined Diagnostic Tool, a software program that automatically allows the Combined Tests Index (CTI) to be calculated. The CTI indicates, in a given subject, the relative probability of a combined series of positive tests being true compared to negative tests. CTI values above 1 indicate a progressively higher chance of a prosthesis being infected and vice versa. Double-blind, prospective evaluation of CTI, compared to intra-operative cultural and histological findings, was performed in a consecutive cohort of 36 patients. 21 patients had positive intra-operative findings for infection. All of them had a pre-operative CTI1 (range: 8.8 to 5552.6; mean: 711 +/- 1298). 15 patients had negative intra-operative results. All had a CTI1 (range: 0.00013 - 0.297; mean 0.074 +/- 0.099). The difference in CTI between the two groups was statistically significant (p = 0.04). Our results show that the Combined Tests Index may be a useful indicator for differential diagnosis of prosthetic infection.

Two-stage revision is the most widely accepted and performed intervention for chronically infected hip prostheses. In recent years short and long stem antibiotic-loaded preformed spacers have become available on the market. The aim of this prospective, comparative study was to assess the safety and efficacy of long stem versus short stem preformed spacers.From year 2000 to 2007 102 consecutive patients underwent two-stage revision of septic hip replacement with a preformed antibiotic-loaded cement spacer and a cementless modular hip revision prosthesis. Patients were divided in two groups: Group L (long stem spacer) (N=60) and Group S (short stem) (N=42) and compared.No systemic toxicity due to local antibiotic release and no spacer breakage were observed in either group. At spacer removal, no statistically significant difference was observed in infection recurrence. After revision, at a mean 4 years follow-up, 2 patients in Group L and 2 in Group S showed infection recurrence. The Harris Hip Score improved in both groups, compared to post spacer implant values: 79.6 ± 15.4 versus 38.4 ± 14.5 in Group L (p < 0.0001) and 82.3 ± 14.4 versus 44.8 ± 16.6 in Group S (p < 0.0001); the difference between groups was not statistically significant.Short and long stem spacers provide comparable low infection recurrence rate and clinical outcome, with negligible risk of breakage and toxicity.

The goal of this review is to present the most updated knowledge derived from basic science, animal studies and clinical trials, concerning biophysical stimulation of bone repair through low-intensity pulsed ultrasound (LIPUS), with particular reference to the management of delayed unions and nonunions. Low-intensity pulsed ultrasound LIPUS has been proved to significantly stimulate and accelerate fresh fracture healing in animal studies and in randomized controlled clinical trials. LIPUS also appears as an effective and safe home treatment of aseptic and septic delayed-unions and nonunions, with a healing rate ranging from 70% to 93% in different, nonrandomized, studies. Advantages of the use of this technology that may avoid the need for additional complex operations for the treatment of nonunions, include efficacy, safety, ease of use and favourable cost/benefit ratio. Outcomes depend on the site of nonunion, time elapsed from trauma, stability at the site of nonunion and host type. The detailed biophysical process by which low-intensity pulsed ultrasound LIPUS stimulates bone regeneration still remains unknown, even if various effects on bone cells in vitro and in vivo have been described.

BIONs/spl trade/ are individually addressable, single channel electrical stimulators that can be injected into one or more muscles through a 12-gauge hypodermic needle. They receive power and command signals from an externally worn RF transmission coil. Two clinical trials are underway to determine their safety and efficacy for strengthening atrophic muscles associated with stroke (7 patients accrued; 6 implanted) and chronic osteoarthritis of the knee (5 patients accrued; 3 implanted). In both studies, BIONs/spl trade/ have proven easy for the clinician to implant and for the patients to use. Thresholds for recruitment of muscle contractions have remained stable and no adverse effects have been reported. Patients generally like the stimulation and most have elected to continue stimulation after the prescribed study period. Stimulation at low frequencies for a total of about 1 hour/day has produced demonstrable reversals of muscle atrophy as measured by imaging. In patients with radiological subluxation of the shoulder, the subluxation has been reduced. Preliminary indications suggest also that chronic pain has been reduced and locomotor function has improved in patients with knee osteoarthritis.

A cyclo-oxygenase (COX)-1 and COX-2 inhibitor (indomethacin) and a selective COX-2 inhibitor (celecoxib) were compared in the prevention of heterotopic ossification after total hip arthroplasty. In 250 patients receiving indomethacin and in 150 patients receiving celecoxib for 20 days after surgery, an overall incidence of heterotopic ossification of 17.5% and 14.3% was seen, respectively (difference not statistically significant: P > .05). No grade III or IV ossifications were seen in either group. Twenty-one patients in the indomethacin group (8.4%) and 3 patients in the celecoxib group (2.0%) required treatment discontinuation, because of side effects (P < .05). Celecoxib, a selective COX-2 inhibitor, shows the same efficacy as indomethacin in the prevention of heterotopic ossification after hip prosthesis with significantly fewer side effects.

We have been using microminiature, single-channel, leadless, RF-powered stimulators called BIONs/sup TM/, in three clinical trials to strengthen muscles weakened by disuse atrophy. Two of these studies are aimed at preventing and reversing shoulder subluxation in post-stroke patients. The third study is aimed at increasing knee function in patients with knee osteoarthritis. Results from these studies (a total of 14 patients implanted) have shown that BIONs are easy for the physicians to implant and easy for the patients to use. Thresholds for recruitment have been stable over time periods as long as 20 months. Significant improvement was seen in the small number of patients under treatment.

INTRODUCTION AND METHODS: Ten currently available classifications were tested for their ability to describe a continuous cohort of 300 adult patients affected by bone and joint infections. Each classification only focused, on the average, on 1.3 ± 0.4 features of a single clinical condition (osteomyelitis, implant-related infections, or septic arthritis), being able to classify 34.8 ± 24.7% of the patients, while a comprehensive classification system could describe all the patients considered in the study. RESULT AND CONCLUSION: A comprehensive classification system permits more accurate classification of bone and joint infections in adults than any single classification available and may serve for didactic, scientific, and clinical purposes.

Background Diagnosis of peri-prosthetic infection remains challenging, often requiring a combination of different tests. Methods In this prospective, case–control study, the diagnostic accuracy of telethermography was evaluated in a group of seventy patients who had had a total knee replacement and were undergoing a reoperation because of infection or another implant-related problem, after a minimum of one year from implant. Results An average differential temperature of the affected versus not affected knee of 1.9°C was observed in infected prosthesis, compared to 0.3°C in aseptic failures. Considering a normal reference value equal or less than 1.0°C, telethermography showed an accuracy, sensitivity, specificity, positive and negative predictive value of, respectively: 0.90, 0.89, 0.91, 0.91, 0.88. Conclusions Digital telethermography is a reliable option for diagnosing peri-prosthetic knee infection.

Background Outcome data on two-stage revision surgery for deep infection after septic hip arthritis are limited and inconsistent. This study presents the medium-term results of a new, standardized two-stage arthroplasty with preformed hip spacers and cementless implants in a consecutive series of adult patients with septic arthritis of the hip treated according to a same protocol. Methods Nineteen patients (20 hips) were enrolled in this prospective, non-randomized cohort study between 2000 and 2008. The first stage comprised femoral head resection, debridement, and insertion of a preformed, commercially available, antibiotic-loaded cement hip spacer. After eradication of infection, a cementless total hip arthroplasty was implanted in the second stage. Patients were assessed for infection recurrence, pain (visual analog scale [VAS]) and hip joint function (Harris Hip score). Results The mean time between first diagnosis of infection and revision surgery was 5.8 ± 9.0 months; the average duration of follow up was 56.6 (range, 24 - 104) months; all 20 hips were successfully converted to prosthesis an average 22 ± 5.1 weeks after spacer implantation. Reinfection after total hip joint replacement occurred in 1 patient. The mean VAS pain score improved from 48 (range, 35 - 84) pre-operatively to 18 (range, 0 - 38) prior to spacer removal and to 8 (range, 0 - 15) at the last follow-up assessment after prosthesis implantation. The average Harris Hip score improved from 27.5 before surgery to 61.8 between the two stages to 92.3 at the final follow-up assessment. Conclusions Satisfactory outcomes can be obtained with two-stage revision hip arthroplasty using preformed spacers and cementless implants for prosthetic hip joint infections of various etiologies.