Total knee revision arthroplasty: comparison between tibial tubercle osteotomy and quadriceps snip approach. Complication rate.

BACKGROUND AND AIM OF THE WORK: The total knee arthroplasty (TKA) revision is not a second time of primary implant surgery but is a very complex issue for orthopedic surgeon. When local conditions make necessary a greater visualization, medial para-patellar access with quadriceps snip (QS) or the osteotomy of the tibial tuberosity (TTO) can be the solutions. This work aims to compare the quadriceps snip and the detachment of the tibial tubercle, focusing on possible complications. MATERIALS AND METHODS: At our institution, between January 2017 and February 2019 52 TKA revision for periprosthetic joint infection (PJI) or aseptic mobilization were performed. In 43 cases an extensive surgical approach was required: for patients with range of movement (ROM) < 60° was chosen TTO, while with ROM > 60° a QS was performed. Clinical and radiological follow-up was available for all the 43 cases. RESULTS: The data about clinical outcome in our study show that both groups have a positive trend in KSS score over time with similar ROM results. Two partial avulsions of patellar tendon during revision surgery were reported. Clinical outcome in both groups has shown good results at the end of follow-up with no post-operative incidence of complications. CONCLUSION: We can assert that both QS and TTO are good approach for TKA revision. Future studies will be needed to understand if preparatory ROM is a good way to decide which surgical approach to use.(www.actabiomedica.it).

Leukocyte esterase strip test as a reliable intraoperative PJIs biomarker. Our experience.

ackgroud and aim of work: Prosthetic joint infection (PJI) is the most common cause of total knee replacement failure and the third most common cause of total hip replacement failure, accounting for 16.8% of all knee revisions and 14.8% of the hip revisions; nevertheless, the diagnosis of PJI is often a challenge for the orthopaedic surgeon. The aim of these study was to evaluate the reliability of the LE strip test for diagnosis of PJI. MATERIALS AND METHODS: From December 2016 to January 2019, we enrolled 50 patients with suspected PJI; 32 females and 18 males, the average age at the time of the surgery was 76 years. Twenty-four patients underwent knee revision surgery and twenty-six hip revision surgery. In all patients during the surgery, the synovial fluid was aspirated and used for leukocyte esterase strip test. The result of the tests was compared to periprosthetic tissues culture, histological examination and sonication fluid culture for PJI. RESULTS: Comparing the results obtained from the LE test with the results obtained from the other diagnostic methods, we found that the concordance between the results of the leukocyte-esterase test and those of the culture test with peri-prosthetic tissue or synovial fluid was shown to be 93%, between LE and histological examinations, the concordance was 93% and finally with the culture of the sonicated fluid the concordance was 86% of the cases. CONCLUSIONS: The results of our serie show a good intraoperative diagnostic accuracy of the LE test, especially in its ability to exclude the hypothesis of periprosthetic infection in case of a negative result.

Onlay versus Inlay humeral steam in Reverse Shoulder Arthroplasty (RSA): clinical and biomechanical study.

BACKGROUND AND AIM OF THE WORK: Reverse shoulder arthroplasty (RSA) is becoming treatment of choice in glenohumeral arthropathies with massive lesion of the rotator cuff, due to a gradual extension of indications and new designs that provide better outcome. In this study we compared two different reverse shoulder prosthesis designs, defined as Inlay (or typical Grammont type) and a relatively new model defined as Onlay (that preserves tuberosity bone stock). We analyzed clinical, biomechanical and radiological outcomes, as well as complications of RSA in these two groups. METHODS: We performed a prospective study on a population of 42 patients undergoing Reverse Shoulder Replacement by a single expert surgeon. We consider 21 patients (group A) who underwent to reverse shoulder replacement with a curved onlay steam with 145° inclination (Ascend Flex group, Wright medical, Memphis, TN, USA)  and 21 patients who underwent to reverse shoulder replacement with a traditional Inlay Grammont steam (Modular Shoulder System SMR, Systema Multiplana Randelli; Lima-LTO, San Daniele del Friuli, Italy) between August 2010 and October 2018. We studied the following items: active range of motion (AROM), radiological parameters (lateralization shoulder angle LSA, Distalization Shoulder Angle DSA), functional scale (Constant-Murley Score), post-operative complications (infection, aseptical implant mobilitazion, residual pain, scapular notching, fractures, tuberosity reabsorbtion, dislocation, bleedings, nerve palsy, pulmonary embolus). RESULTS: A significant improvement in ROM and functional score (Constant Shoulder Score) were observed in both groups. Group A (Onlay design 145°, medial tray) provides improvement in adduction, extension and external rotation compared to group B. No significant differences were found in abduction, external rotation and forward flexion. At 6 months follow-up, pain relief was detected in all patients. Although complications occur in a high percentage of patients in literature, no postoperative complications were observed in our cases series. CONCLUSIONS: Our results showed how RSA is a real solution to improve quality of life and to restore pain-free shoulder ROM in patients where cuff tear arthropathy occurs. Onlay design 145° may provides better active external rotation, extension, adduction: it is necessary to continue follow up and include more cases to prove these data.

Pre-operative and post-operative kinematic analysis in total knee arthroplasty. A pilot study.

INTRODUCTION: Total knee replacement is the treatment of choice in knee osteoarthritis. Despite this, there is still a percentage of unsatisfied patients. Recently, prosthetic designs have been developed to improve the kinematics of the prosthetic knee. MATERIALS AND METHODS: Between June 2016 and November 2016 we enrolled 26 patients underwent to total knee arthroplasty divided in two groups (A and B) treated respectively with Journey 2 implant and the Attune impltant. Each patient was evaluated with functional scores (KOOS and KSS) and with kinematic analysis using the Bioval System. RESULTS: In the group A, compared to the pre-operative, the flexion of the operated knees is significantly increased (31.27°±3.13° → 35.02°±2.1°) as well as that of the unoperated knee (34.34°±2.8° → 35.39°±3.5°). The pre/post-operative comparison of the muscles' activation timing showed an improvement for the unoperated side, which is closed to the physiological pattern, while the operated side showed an incorrect activation of all the investigated muscles. CONCLUSIONS: The Journey 2 prosthesis seems to reach better results in rotational flexion, rotational freedom and muscles activation during free walking. Furthermore, it seems that with this prosthesis the patient can feel his "new prosthetic knee" more similar and closer to the physiological one. More studies are needed to confirm these results.

Comparison between standard technique and image-free robotic technique in medial unicompartmental knee arthroplasty. Preliminary data.

The factors that guarantee the survival of the unicompartmental prosthesis implant seems to be linked to the accurate positioning of the components. The aim of our study is to compare the standard operative technique and the assisted navigation technique to understand if the robotic technology is able to obtain more accurate implants and with a better outcome. In the period between January 2016 and February 2018, in our Clinic, were performed 94 medial unicompartmental knee implants. The implantation of the medial unicompartmental prosthesis was performed in 30 cases with the standard technique and in 29 cases with the image-free robotic technique (Navio Surgical System). The objective of our study was to evaluate the anatomical and mechanical axes, the tibial slope, the coronal inclination of the femoral tibial space, the coronal angulation of the tibial and femoral component and the height of the Joint-Line. Furthermore, to evaluate the outcome we has execute international scores (IKDC and KSS Insall mod.). The advanced navigation seems to allow the implantation of the unicompartmental prosthesis more precisely, although not always with a statistically significant difference compared to the standard technique. further clinical studies are needed to analyze the medium and long-term survival rate, as well as the patient's subjective outcome.

Rotator cuff tears reparability index based on pre-operative MRI: our experience.

BACKGROUND AND AIM OF THE WORK: It is recognised that a significant percetage of large and massive rotator cuff tears (RCT) cannot be anatomically repaired and this correlates with a worste outcome in terms of pain, active range of motion, increased incidence of retair. The aim of our work is to find reliable index on preoperative MRI shoulder image to assist orthopaedist in surgical planning of rotatator cuff tears repair. METHODS: We performed a retrospective study on a population on 131 patients undergoing arthroscopic cuff repair by a single expert surgeon. Pre-operative MRI images were evaluated by a single orthopaedist, trained on MRI shoulder images ad blinded to surgical outcome. For each magnetic resonance we evaluated the following 9 parameters: fatty Infiltration (FI), Patte Stage (PS), tear size measured in medial-lateral (ML) and anterior- posterior (AP) dimension, Tangent Sign (TS), Occupation Grade (OG), Acromion-Humeral Distance (AHD), Inferior Gleno-Humeral Distance (IGHD), Glenoid Version Angle (GVA). We divided population into two groups: patients who obtained a complete repair of RCT (n=110) and patients who obtained only a partial repair of RCT (n=21). For each MRI index we conducted statistical analysis (Student's t test, Mann- Whitney U test, Shapiro-Wilk test, Chi-square test, Fisher exact test, ROC curves and maximum Youden index) to find a Cut Off value useful to predict partial repair. RESULTS: We have found statistical significance in predicting partial repair on MRI mesurements of Fatty Infiltration (FI grade ≥3; test di Fisher p<0.001), Patte Stage (grade= 3; test di Fisher p<0.001), Tear size measured in ML (>36 mm; Mann-Whitney p<0.001), Positive Tangent Sign (Chi-quadro p<0.001; sensitivity 95,3%, specificity 83,6%), Occupation Grade (OG <0,46; t-test p<0.001). Acromion-Humeral Distance (AHD <7 mm), Inferior Gleno-Humeral Distance (IGHD >5 mm). Tear size measured in AP (>21 mm; Mann-Whitney p<0.001) seems to be dependent on the contextual size of the lesion in ML. We haven't found statistical significance in predicting partial repair of Glenoid Version Angle. CONCLUSIONS: A systematic observation of seven independent MRI parameters (FI, PS, tear size ML, TS, OG, AHD, IGHD) can help the surgeon to predict the impossibility to obtain complete repair of RCT and to consider different surgical approach.

Heterotopic Ossification in Primary Total Hip Arthroplasty: which is the role of drainage?

BACKGROUND AND AIM OF THE WORK: The Heterotopic Ossification (HO) is a common complication following Total Hip Arthroplasty (THA). Although there is no concordance in Literature regarding the etiopathogenic mechanism, various HO risk factors have been recognized, both related to the patient and associated with the surgical procedureLiterature does not consider the use of intra-articular drainage as a possible risk factor. Our hypothesis is that this item can contribute to the development of HO. MATERIALS AND METHODS: 425 implants of hip arthroplasty performed between 2014 and 2017 at the Ortopedic Clinic of Udine were included in the study. No patient performed pre-operative or post-operative anti-HO prophylaxis during follow-up. Radiographs of preoperative and postoperative at 1 year were analyzed according to the Brooker Classification. RESULTS: The incidence of HO in patients with intra-articular drainage is 24.6%, while the incidence of HO in patients without intra-articular drainage is 15.3%, with a statistically significant difference. CONCLUSIONS: The data obtained suggest to consider the use of intra-articular drainage as a possible intra-operative risk factor for HO. This is a retrospective cohort study, so we need more studies and more robust experimental designs to confirm these results.

Arthroscopic treatment of iliopsoas impingement syndrome after hip arthroplasty.

BACKGROUND AND AIM OF THE WORK: Groin pain after hip arthroplasty (HA) ranges from 0.4% to 18.3%. Defining the cause of groin pain after HA can be difficult. Iliopsoas impingement (IPI) has been reported to be the underlying cause of groin pain in up to 4.4% of cases. The purpose of this study is to present arthroscopic surgical outcomes in the treatment of IPI after HA. METHODS: Between September 2013 and March 2018, 13 patients, 11 total hip arthroplasty (THA), 1 hip endoprosthesis and 1 total hip resurfacing affected by groin pain due to unceasing iliopsoas tendinopathy for impingement after HA were treated arthroscopically. The patients underwent to physical examination, blood analysis, hip X-rays, bone scintigraphy and CT assessment. We performed the arthroscopic OUT-IN access to hip joint in all patients. VAS scale, Harris Hip Score (HHS) and Medical Research Council (MRC) scale were performed before surgery and during follow up at 1-3-6-12 months. RESULTS: After 10 months of mean follow-up, average HHS and MRC scale improved significantly from preoperatively to postoperatively. No complications arose in our case series. CONCLUSIONS: Hip arthroscopy after hip arthroplasty is supported in the literature for a variety of indications. Hip arthroscopy is a viable and reproducible technique in treatment of IPI, being less invasive than the classic open technique. This simple arthroscopic release provides satisfactory results and preserves HA function. Moreover an arthroscopic OUT-IN access proves good clinical outcomes, few complications and iatrogenic lesions.

Can UKA after KineSpring system failure be a viable option? A case report.

BACKGROUND AND AIM OF THE WORK: The KineSpring System is an alternative treatment offered in selected symptomatic patients suffering from mild to moderate medial knee osteoarthritis (OA). This device reduces medial compartment loads in the OA knee without compromising the integrity of the lateral or patellofemoral knee compartments, maintaining the normal knee anatomy. Currently, papers about KineSpring System installation show promising results. The current authors describe a case of unicompartmental knee arthroplasty (UKA) employed to treat medial knee OA after Kinespring system failure. METHODS: A 64-year old male patient presented to our hospital after failure of a Kinespring system implantation into his left knee at an external hospital, where the outcomes obtained were not satisfactory. The surgical options discussed with the patient were the TKA or medial UKA. A medial UKA was preferred by the patient. RESULTS: One year from UKA, the patient complained of frequent joint effusions and weight bearing pain despite a good ROM without radiographic signs of implant loosening. Therefore, after two years we replaced UKA with total knee arthroplasty (TKA). CONCLUSIONS: Further experience is needed to provide reliable clinical data about the results of the UKA after KineSpring System discharge.

Rivaroxaban and early periprostethic joint infection: our experience.

BACKGROUND AND AIM OF THE WORK: Periprostethic joint infection (PJI) is a severe post-operative complication after Primary Total Hip Arthroplasty (THA). According to the classification of PJI early acute PJI occurs within 4 weeks from surgery. Some authors think that Rivaroxaban is a risk factor in the incidence of early acute PJI. We analyze our experience about this item. MATERIALS AND METHODS: We analyze our experience from 1st January 2015 to 31th December 2016. We consider all consecutive hip arthroplasty implants in this period. RESULTS: In the 205 patients analysed we not find early acute PJI in Rivaroxaban group nor in the others assuming another kind of thromboprophylaxis. CONCLUSIONS: In our series there is no evidence of association between Rivaroxaban and early acute PJI. This is a retrospective cohort study, so we need more studies and more robust experimental designs to confirm these results.

The SMR reverse shoulder arthroplasty in rotator cuff arthropathy management.

BACKGROUND AND AIM OF THE WORK: Cuff tear arthropathy (CTA) is a well-defined  degenerative pathology  of the shoulder. When conservative treatments are unable to permit a good quality of life, the reverse shoulder arthroplasty (RSA) can guarantee a good restitution of range of motion, function and strength of the shoulder without pain. In this paper we show our clinical, functional and radiological outcomes, as well as complications of RSA in patients with CTA. METHODS: We analyzed 31 patients who underwent to reverse shoulder replacement with Modular Shoulder System (SMR, Systema Multiplana Randelli; Lima-LTO, San Daniele del Friuli, Italy) reverse shoulder system, between August 2010-July 2014. RESULTS: A significant improvement in ROM and functional scores (Constant Shoulder Score and UCLA score) were observed in our cases series. At the time of follow-up  pain relief was detected in 28 patients and 3 patients declared mild pain. Overall, 90.3% of patients rated their satisfaction as good or excellent. Although  complications occur in a high percentage of patients in literature, no postoperative complications was observed in our cases series. CONCLUSIONS: Our results showed how reverse shoulder arthroplasty is a real solution to improve quality of life, to restore pain-free ROM, function and strength of the shoulder in patients where cuff tear arthropathy occurs.

Computer assisted total knee arthroplasty: a real navigation to better results?

BACKGROUND AND AIM OF THE WORK: Computer assisted surgery in knee replacement is still in discussion, but majority of papers affirm an increase of the accuracy in alignment. Aim of our study is to evaluate the accuracy of mechanical axis, the posterior tibial slope and the femoral component rotation with navigation, x-ray and CT data. METHODS: We have analysed 145 patients who underwent total knee arthroplasty between January 2012 and December 2014. We have checked each patient at 6, 12 and 24 months of follow-up. During each visit, we did a clinical evaluation checking the ROM and a clinical score (KOOS). At 2 years, we did a CT evaluation and a plain x-ray evaluation. RESULTS: 125 patients have completed the follow-up. Mean follow-up time was 2,6 years. Both ROM and KOOS values increased during follow-up. About the mechanical axis, both x-ray and CT data showed a mean deviation <2° from the target. About posterior tibial slope and femoral component rotation, CT data showed a mean deviation of <3° from the target. Mean difference between navigation and CT data was <1°. CONCLUSIONS: According to literature data, our data confirm that computer assisted surgery in knee replacement have a good accuracy of coronal alignment, rotational alignment and posterior tibial slope.

Acute periprosthetic knee infection: is there still a role for DAIR?

BACKGROUND AND AIM OF THE WORK: Periprosthetic knee infection is a rare complication associated with prosthetic failure; incidence change from 0,4-2% of primary total knee replacement and 5.6% in revisions. Indications for debridment, antibiotics and implant retention (DAIR) are early acute infections or acute delayed infection. Aim of the work is to check if this technique is still a successful in early infections. METHODS: We have analyzed recent literature data on DAIR and all DAIR procedures in our clinic in the last 10 years, the mean time between onset of symptoms and surgery, the mean antibiotic therapy duration and results we have obtained. We evaluate the diagnostic process and different treatments in early knee periprosthetic infections, especially the DAIR approach. RESULTS: If correct indications are followed, DAIR has a success rate in 31-100% of the cases; if it is applied in late chronic infection the success rate is 28-62%. In our experience DAIR has an 80% success rate: in 20 patients treated with DAIR we had 4 failures. CONCLUSIONS: DAIR can be considered a successful treatment, but it depends from individual patient factors, from the microorganisms involved, from the duration of antibiotic therapy and from correct choice in timing and in execution of DAIR by the orthopedic surgeon.

Two-stage revision after total knee arthroplasty.

BACKGROUND AND AIM OF THE WORK: Periprosthetic knee infection is a complication associated with prosthetic failure; incidence change from 0,4-2% of primary total knee replacement and 5,6% in revisions; incidence is increasing over the years. Two-stage revision is the technique used in chronic infection. Aim of the work is to check success rate in our data. Methods. We analyzed retrospectively data of patients who undergone two stage revision surgery between 01/01/2010 to 31/12/2015. We made a clinical and radiological control after 1, 3, 6, 12, 24 months and we evaluate the outcome in December 2016. Results. Between 2010 and 2015 we treated 45 patients with two-stage revision. Mean follow-up was 3,4 years. Success rate is 89,9%. We had failure in 5 patients: everyone had knee surgery before first knee arthroplasty and Charlson Comorbidity Score was greater then 4 in 4 cases. Conclusions. Two stage revision can be considered a successful treatment in chronic periprosthetic knee infection. It has an optimal success rate, but it has some disadvantages as joint stiffness and pain in the interval between stages. This is a technique with two major surgery procedure with associated morbidity, discomfort, cost and prolonged stay in hospital.

Histopathological aspects and staging systems in non-traumatic femoral head osteonecrosis: an overview of the literature.

BACKGROUND: The pathogenesis of non traumatic osteonecrosis of the femoral head (ONFH) has not yet been established. The literature shows a variable nomenclatura for this condition that often leads to confusion. Several risk factors have been identified but histopathological and radiological outcomes are common. PURPOSE: To provide the overview on the current knowledges about the nomenclatura, etiology, disease progression, relationship between histopathological changes and imaging techniques in order to stage the disease accurately. Etiology and pathogenesis: Genetic predisposition, metabolic factors, local factors affecting blood supply such as vascular damage, increased intraosseous pressure and mechanical stress are involved in this desease. The final results are bone ischemia and infarction getting bone deathand FH collapse. Histopathological aspects and staging systems: Several staging systems have been developed to stage ONFH based on imaging techniques.The  subchondral collapse, the size or quantification of the lesion, and the lesion location within the femoral head are identified as the most important prognostic factors in ONFH disease. Histological analysis plays a critical role to evaluate the quality of necrotic area and the differences between microscopic, macroscopic and imaging outcomes were detected. CONCLUSIONS: an ideal staging system is necessary to stage ONFH desease to detect several aspects, but itìs more difficult to create. At the present time we summarize some aspects that are advisable to focus during ONFH for the correct treatment.

The role of intraoperative frozen section in arthroplasty revision surgery: our experience.

BACKGROUND AND AIM OF THE WORK: Due to the increasing the number of hip and knee replacement in the future will be increasing the number of cases of prosthetic revision. Our aim is to test the validity of extemporaneous exam for differentiation between septic and aseptic loosening of prosthetic. METHODS: 159 patients underwent surgery for the prosthesis revision from 2008 to 2014 An intraoperative histological examination was performed during all the surgeries and multiple samples were taken for the conclusive histological examination and culture. RESULTS: Sensitivity of the intraoperative histological examination resulted 38,3% (IC 0,26; 0,51); specificity 82,5% (IC 0,73; 0,90), where positive predictive value was 57,5% (IC 0,41; 0,73) and negative predictive value 68,4% (IC 0,59; 0,76). CONCLUSIONS: In the absence of a universally accepted method to diagnose infection in patients with mobilization of the prosthesis, intraoperative histological examination is, in spite of everything, a method easy to perform and reproduce, it shows high specificity and sensitivity in the presence of highly virulent pathogens.

Extracapsular vs standard approach in hip arthroscopy.

BACKGROUND: Over the last decades, the arthroscopic treatment of hip pathology has highly grown thanks to the evolution of surgical and diagnostic techniques and instrumentation development. Furthermore the higher life expectancy and functional request make younger patients to be evaluated more frequently for non-arthrosic hip pathologies like labral lesion, FAI, cartilage tears. Treatment substantially has to be chosen between arthroscopy and arthrotomy. This study pretends to compare the clinical outcome between two different arthroscopic access techniques: the traditional one and the extrarticolar one (OUT-IN) we are using regularly in our clinic. METHODS: From 2012 to 2014, 37 patients with FAI were treated with traditional technique (Group A) and 28 with extra-articular access (Group B). Indication to surgery treatment was given on the basis of radiological imaging (Pelvis Rx, Hip Rx in AP, Frog Leg view, Dunn view, Pelvic MRI) (8, 9), dynamic range of motion, clinical examination and functional scores (MHHS, MHOT). Pain was scored with NRS.  Minimum follow up for each patient was 12 month with clinical controls and functional score recording at 3-6-12 month after surgery. Complications or iatrogenic lesions were assessed. RESULTS: At 12 month after surgery there was no statistically significant differences in hip R.O.M., MHHS and MHOT (33) score. We observed an higher number of iatrogenic lesions and complications in the group A (standard technique) than group B. CONCLUSIONS: Hip arthroscopy is a viable and reproducible alternative technique when treating articular lesion such as femur-acetabular impingement and it is demonstrated by the increase of functional score. We can furthermore appreciate that an extra-articular access technique leads to a vary good outcome both in hip R.O.M. and functional scores and has a very low number of complications and iatrogenic lesions.

Arthroscopic rotator cuff repair with or without PrP: our experience.

BACKGROUND AND AIM OF THE WORK: Arthroscopical rotator cuff repair has good results, but the rate of tendon healing is 80% in small tears with a decrease to 30% in large and massive tears. Platelets are an endogenous source of growth factors present during rotator cuff healing. Aim of the work is checking if Cascade Autologous Platelet System may improve rotator cuff healing in small sovraspinatus tears. METHODS: Each patient enrolled in cases  has surgical arthroscopical repair of sovraspinatus  small tear and then treated with intraoperatory Cascade. Patients of control group undergoing the same surgery with traditional arthroscopic repair. Follow-up time was at 3, 6, 12 month from surgery with evaluation of ROM, strength, Constant score, NRS. RMN was repeated at 12 month from surgery with evaluation of sovraspinatus tendon thickness, signal intensity, fat degeneration and muscle atrophy. RESULTS: Between 2010 and 2013, 18 patients have undergone sovraspinatus repair in arthroscopic surgery  with intraoperatory Cascade and 18 patients with traditional arthroscopic repair. Only sovraspinatus tendon thickness and  signal intensity were  statistically difference in the cases group. In ROM, strength, Constant score, NRS, fat degeneration and muscle atrophy were not a statistically difference compared with controls. CONCLUSIONS: In small sovrapinsatus tears Cascade Autologous Platelet System did not result in improved ROM, strength, Constant score, NRS, tendon fat degeneration and muscle atrophy. Only sovraspinatus  tendon thickness and  signal intensity were improved.

Current antibiotic management of prosthetic joint infections in Italy: the 'Udine strategy'.

The rate of prosthetic joint infections followed and cured at our institution is constantly increasing, in line with epidemiological data from the recent literature. This is probably related to the greater number of knee and hip prostheses implanted every year. For intermediate and late infections, only the two-stage approach is applied, as this demonstrates the best outcome in our experience. Particular attention is paid to microbiological isolation of the pathogen: multiple samples of tissue are collected during the interventions, and kept in culture for a longer period of time than usual. Sonication of prosthetic devices is used to enhance the sensitivity and specificity of the microbiological cultures. Histological examination influences surgical choices either towards implantation of a new prosthesis or replacement of the spacer. An empirical antibiotic backbone of a glycopeptide/lipopeptide and rifampicin is chosen, due to the leading role of Gram-positive bacteria in this setting and the high incidence of methicillin resistance in our centre (>30%), followed by an antibiotic regimen containing linezolid. If specific risk factors are present, an anti-Gram-negative drug is added to the regimen. Duration of therapy depends upon the approach that is chosen, usually being 6 weeks when the prosthesis is removed. Despite at the moment being limited by its small sample size, data from our experience confirms that our empirical approach may represent a valid choice during the early phase of treatment, by keeping linezolid for a step-down therapy of shorter duration (4 weeks).