Worrying Presence of Asymptomatic Bacterial Colonisation on Implanted Orthopedic Devices.

Background Bacterial infection after hardware implantation in orthopedic and trauma surgery is devastating, resulting in increased hospital costs and stays, multiple revision surgeries, and prolonged use of antibiotics. The present study aims to determine whether a symbiotic relationship between the human organism and bacteria in hardware implantation may be present, without clinically evident infection. Materials and methods We studied explanted devices for microbiological analysis, using the sonication technique, from patients who underwent surgical removal of musculoskeletal hardware for mechanical reasons. None of the patients included in the study had clinical or biochemical signs of infection. Results Forty-nine patients were enrolled. Cultures tested positive for bacteria in 42.8% of the 49 patients (21 of 49). In 13 patients, Gram-positive bacteria were isolated, while Gram-negative bacteria were isolated from nine patients. The most frequent bacterial species found was Pseudomonas aeruginosa, with six positive cultures (28.5%). Coagulase-negative staphylococci were isolated from ten implants (47%). Conclusion A pacific coexistence between humans and bacteria is possible following the implantation of metallic devices for trauma or orthopedic ailments. It is still unclear how strong or unstable this equilibrium is.

Are Rush Nails Still a Good Choice for Fibula Fixation in Ankle Fractures? A Retrospective Study with Five Years Follow-Up.

Objectives: The aim of this retrospective study is to evaluate if Rush nail fixation still has a role in distal fibular fractures surgery compared with locking plate in terms of fixation quality, complications, functional results and patient satisfaction level. Methods: This study included 109 patients (average age 56.05), who had undergone operative treatment for bi- or trimalleolar fractures between 2009 and 2014. The patients were evaluated retrospectively, divided in group A (57 patients treated with Rush nail) and group B (52 patients treated with locking plate). The patients were evaluated at an average 4.9 years of follow-up (SD: 1.01) with Olerud-Molander Ankle Score (OMAS), American Orthopedic Foot and Ankle Society - Ankle-Hindfoot Scale (AOFAS) and Visual Analogue Scale (VAS) for clinical outcomes. X-rays were conducted to assess ankle osteoarthritis using the classification system by Takakura and joint space symmetry using measurements in comparison with contralateral ankles. Results: The groups were homogeneous regarding age and gender. Patients treated with Rush Nail fixation (Group A) showed statistically significant worse clinical results at functional scores (78.1 Group A versus 88.7 Group B at the OMAS (P<0.05); 83.1 Group A versus 90.1 Group B at the AOFAS (P<0.05); higher pain levels in the VAS (3.9 Group A versus 2.4 Group B) and lower satisfaction rates (52.6% Group A versus 73.1% Group B (P<0.05)) in comparison with patients treated with locking plate fixation (Group B). However, infections rate was significantly lower in Group A (1.8%) than in Group B (9.6%) (P<0.05). Radiographic evaluation showed more cases of post-traumatic osteoarthritis in Group A (35.1% Group A versus 15.4% Group B (P<0.05)) and worse results in regards to restoration of joint space symmetry (45.6% Group A versus 73.1% Group B (P<0.05)). Conclusion: Results of current study indicates that even though plating of lateral malleolus in bimalleolar and trimalleolar fractures is superior in fracture reduction quality, early functional recovery, reduced incidence of post-traumatic osteoarthritis and greater patient satisfaction, Rush nail fixation still provides acceptable clinical results with a lower infection rate. Therefore Rush nails could be considered as a valid choice in selected patients with high risk of soft tissue complications or low functional demand.

In-office needle arthroscopic assessment after primary ACL repair: short-term results in 15 patients.

PURPOSE: In-office needle arthroscopy has been reported as a diagnostic tool for different knee pathologies. In addition, ACL repair has seen a resurgence with the advent of innovative orthopedic devices. The aim of this study was to assess clinical, radiological, and in-office needle arthroscopic findings in 15 adult patients who underwent acute (within 14 days from injury) anterior cruciate ligament (ACL) repair. METHODS: Fifteen patients voluntarily participated in the study. A second-look arthroscopy was performed with an in-office needle arthroscopy at an average of 7.2 months after the primary repair. The parameters included in the investigation were the continuity of the anatomical footprint of the repaired ACL, subjective assessment of the ACL tension with the probe, and synovial coverage of the ACL. All patients had a Magnetic Resonance Imaging (MRI) at 6 months after repair and an arthrometric evaluation with the KT-1000. Clinical evaluation with the scores, Tegner Lysholm Knee Scoring Scale (TLKSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) was performed at the final follow-up of 2 years. Moreover, a correlation between the characteristics of ACL appearance at the time of the second look in-office needle arthroscopy, MRI and KT-1000 was performed. RESULTS: The mean TLKSS was 97.86, the mean KOOS was 98.08 and the mean subjective IKDC was 96.71. The objective IKDC was A in 10 patients and B in 5 patients. ACL healing was graded as A in 11 patients and B in 4 patients. Synovial coverage was graded as good in 10 patients and fair in 5 while MRI assessment showed a type I ACL in 10 patients, type II in 4 patients and type III in 1 patient. CONCLUSION: In-office needle arthroscopy is a reliable tool to assess the condition of a repaired ACL. In addition, ACL repair performed in acute proximal tears demonstrated excellent clinical results.

Saucerization and suture of symptomatic bilateral medial discoid meniscus in a 13 years old male football player: a case report and literature review.

Introduction: Medial discoid meniscus is estimated to occur in 0.06% to 0.3% of the population, being bilateral medial discoid menisci. The current tendency to be very conservative in treating meniscal lesions should be applied to the discoid meniscus, too, so that the cauterization and suture of a torn discoid meniscus are gaining support. Case presentation: We present the case of a 13-years-old Caucasian male competitive football player with a diagnosis of bilateral medial discoid menisci. Arthroscopy of the left symptomatic knee found an incomplete medial discoid meniscus, with an atypical hypertrophic posterior horn and root with a lack of rear tibial attachments. Saucerization to obtain a standard semilunar shape plus outside-in sutures to repair the horizontal tear and stabilize the meniscus's peripheral rim was performed. The asymptomatic right knee was treated conservatively. After seven months, complete resolution of the symptoms in the left knee and no worsening of symptoms in the right knee was reported. Conclusion: Bilateral discoid medial meniscus is a rare abnormality involving active young patients. The conservative treatment is the preferred option in asymptomatic patients. Sauceriziation and eventual repair represent the suggested surgical treatment in symptomatic cases.

Injuries During Return to Sport After the COVID-19 Lockdown: An Epidemiologic Study of Italian Professional Soccer Players.

Background: The injury rate in professional soccer players may be influenced by match frequency. Purpose: To assess how changes in match frequency that occurred because of coronavirus disease 2019 (COVID-19) influenced training and match injuries in the Italian Serie A league. Study Design: Descriptive epidemiology study. Methods: Three phases in the Serie A league, each 41 days long, were evaluated: phase A was the beginning of the 2019-2020 season; phase B was a period after the COVID-19 lockdown was lifted, when the remaining matches of the season were played with greater frequency; and phase C was the beginning of the 2020-2021 season. All male professional soccer players who were injured during the 3 phases were included. Player age, height, position, injury history, and return to play (RTP) were retrieved from a publicly available website. Training- and match-related injuries during each of the 3 phases were collected and compared. Moreover, match injuries that occurred after the lockdown phase (phase B), in which there were 12 days designated for playing matches ("match-days"), were compared with injuries in the first 12 match-days of phases A and C. Results: When comparing 41-day periods, we observed the injury burden (per 1000 exposure-hours) was significantly lower in phase B (278.99 days absent) than in phase A (425.4 days absent; P < .05) and phase C (484.76 days absent; P < .05). A longer mean RTP period was recorded in phase A than in phase B (44.6 vs 23.1 days; P < .05). Regarding 12-match day periods (81 days in phase A, 41 days in phase B, and 89 days in phase C), there was a significantly higher match injury rate (0.56 vs 0.39 injuries/1000 exposure-hours; P < .05) and incidence (11.8% vs 9.3%; P < .05) in phase B than in phase A and a longer mean RTP period in phase A than in phase B (41.8 vs 23.1 days; P < .05). Finally, the rate and incidence of training-related injuries were significantly higher in phase B (4.6 injuries/1000 exposure-hours and 6.5, respectively) than in phase A (1.41 injuries/1000 exposure-hours and 2.04, respectively) (P < .05). Conclusion: Both training- and match-related injuries were greater during the abbreviated period after the COVID-19 lockdown. These may be linked to the greater match frequency of that period.

Impact of Anterior Cruciate Ligament Injury on European Professional Soccer Players.

BACKGROUND: The impact of anterior cruciate ligament reconstruction (ACLR) on the performance and career of professional soccer players has not been extensively investigated. PURPOSE: To evaluate in professional European soccer players (1) the ACL injury incidence, (2) the return-to-play (RTP) rate and time after ACLR, (3) career survival and athlete performance in the first 3 postoperative seasons after RTP, (4) factors likely related to different outcomes after ACLR, and (5) any related differences between the top 8 European soccer leagues. STUDY DESIGN: Descriptive epidemiology study. METHODS: Included were professional soccer players in the top 8 European Soccer leagues (Serie A [Italy], Premier League [England], Ligue 1 [France], LaLiga [Spain], Bundesliga [Germany], Jupiler Pro League [Belgium], Liga NOS [Portugal], and Premier Liga [Russia]) who sustained an ACL injury during seasons 2014 to 2015, 2015 to 2016, and 2016 to 2017. Data were retrieved from publicly available online sources. Outcomes were evaluated based on player age (<25 years, 25-30 years, and >30 years), position (goalkeeper, defender, midfielder, and forward), affected side (dominant vs nondominant), and league. RESULTS: Overall, 195 players sustained an ACL injury, for a mean annual ACL injury incidence of 1.42%. The RTP rate was 95%, with a mean RTP time of 248 ± 136 days. Within the third postoperative season, 66 players (36%) competed in a lower level national league, and 25 (13.6%) ended their careers; a significant reduction in the mean minutes played per season was found in all 3 postoperative seasons. Player age correlated significantly with reduction in performance or recovery from an ACL injury. No significant correlation was found between postoperative player performance and affected side, position, league, or time to RTP. CONCLUSION: A substantial ACL injury incidence was found in top European elite soccer players; however, a high RTP rate in a reasonable time was seen after ACLR. Nevertheless, professional soccer players experienced a short-term decline in their performance.

Bilateral Post Traumatic Myositis Ossificans of Adductor Longus in a Young Soccer Player: A Case Report and Literature Review.

ABSTRACT: Myositis ossificans traumatica (MOT) is a self-limiting and self-resolving pathology. In most cases, conservative treatment is chosen as the first step. Surgical treatment is reserved for cases of failure of conservative treatment with persistence of pain and mass. The case presented concerns an 18-year-old soccer player suffering from bilateral adductor longus (AL) MOT results following two different sports injuries. The patient reports the appearance of swelling and palpable mass at the proximal and medial region of the thigh, about 2 cm from the pubic symphysis, along the course of the adductor magnus. The radiological investigation showed the presence of a calcification along the course of the right and left AL muscles. Surgical treatment was considered for the right thigh injury, being symptomatic 1 year after the onset and refractory to other treatments. At 3 months of follow-up, the patient was asymptomatic and completed the rehabilitation program for the recovery of muscle strength and range of motion (ROM). In cases where MOT manifests with resistant pain, ROM restriction and daily activity reduction, surgical excision is the preferred option.

Combined ACL and Segond Repair in Combined Acute Proximal ACL Tears and Segond Fracture.

A renewed interest in anterior cruciate ligament preservation has been noted using arthroscopic primary repair in patients with proximal tears, but the main concern remained the control of the rotational instability. Segond fracture occurs in less than 10% of cases of acute anterolateral instability, but it can result in continued rotation instability. The aim of this study is to describe the surgical technique to acutely repair both the anterior cruciate ligament and Segond fracture in the acute setting.

Segond Fractures Involve the Anterolateral Knee Capsule But Not the Iliotibial Band.

PURPOSE: To investigate the relationship between the Segond fracture and the anterolateral complex of the knee. METHODS: Between January 2014 and March 2020, patients who presented with an anterior cruciate ligament (ACL) tear requiring acute surgical reconstruction (within 10 days from trauma) were evaluated for inclusion in this study. Patients were included if they had an acute ACL tear with an associated Segond fracture (or "Segond lesion") as detected by radiograph or magnetic resonance imaging. The lateral compartment was exposed in all cases using a 5-cm lateral hockey-stick incision, which was carried down to the iliotibial band. The fascia lata was first inspected and then longitudinally divided along its fibers to expose lateral compartment. The posterolateral corner to Gerdy's tubercle anteriorly was exposed and examined. Once the Segond fracture was identified, it was recorded and photographed. RESULTS: Seventeen patients were enrolled in the study. Dissection of the Segond fracture demonstrated attachment to the anterolateral capsule only. No other discernible attachment to the Segond fracture was noted. Surgical exploration of the anterolateral knee did not reveal injury to the iliotibial band. CONCLUSIONS: Careful dissection of Segond fractures during repair revealed that there is a discernible attachment with the anterolateral capsule to the bone injury in all patients with acute ACL tears undergoing surgical reconstruction and no connections to the iliotibial band. CLINICAL RELEVANCE: The precise pathogenesis of Segond fractures has been the subject of debate, partially due to the complexity of the anatomy of the anterolateral aspect of the knee. Proper understanding of the anatomy of type IV ALL injures with Segond fractures is important to improve treatment of these injuries.

Acute Primary Repair of the Anterior Cruciate Ligament With Anterolateral Ligament Augmentation.

Acute injuries of the anterior cruciate ligament are often associated with concurrent injuries to the structures of the anterolateral complex, specifically the anterolateral ligament. Some injury patterns of the anterior cruciate ligament involve tearing of the majority of the ligament from the femoral origin, leaving a large, viable ligament remnant. In these patients, a repair of the anterior cruciate ligament back to the femoral origin can be undertaken. Subsequently, percutaneous repair of the anterolateral ligament can be performed through anatomical, percutaneous suture tape augmentation. The combined technique of anterior cruciate ligament repair with anterolateral ligament reinforcement is presented.

Accuracy and Cost-Effectivenss of a Novel Method for Alpha Defensins Measurement in the Diagnosis of Periprosthetic Joint Infections.

BACKGROUND: Two methods for detecting synovial fluids alpha defensins are available: the enzyme-linked immunosorbent assay and the lateral flow test. For both, the proper role and accuracy remain uncertain. The purpose of this study was to assess the accuracy of the matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) for alpha defensin detection in synovial fluids of patients with total knee arthroplasty/total hip arthroplasty failures. The hypothesis was that the alpha defensin measurement through MALDI-TOF MS assay could be a high sensitive and specific test for periprosthetic joint infections (PJI) diagnosis as compared with Musculoskeletal Infection Society (MSIS) criteria. METHODS: The study included 138 patients. The 2018 MSIS criteria were used to diagnose PJIs. Synovial fluids were assessed for routinely synovial fluid tests and alpha defensin measurement through MALDI-TOF MS. Sensitivity, specificity, overall diagnostic accuracy, positive and negative predictive values, receiver operator curves, and area under the curve were calculated. RESULTS: As per the 2018 MSIS criteria, 59 PJIs (43%) and 79 aseptic failures (57%) were diagnosed. The MALDI-TOF MS assay showed an overall accuracy of 94.9%. The sensitivity was 93%, the specificity was 96%, the positive predictive value was 95%, and the negative predictive value was 95%. Receiver operator curves analysis demonstrates an area under the curve of 0.95 (P < .001). CONCLUSION: The MALDI-TOF MS assay showed high sensitivity and specificity for alpha defensin detection in case of total knee arthroplasty/total hip arthroplasty failures. The advantages of the technology, such as the few milliliters of sample needed, the rapidity of obtaining results, and the cost-effectiveness of the procedure could make the MALDI-TOF MS alpha defensin assay a useful and widespread test in clinical practice.

Do serum markers correlate with invasiveness of the procedure in THA? A prospective randomized study comparing direct anterior and lateral approaches.

BACKGROUND: Advantages of minimally invasive approaches for total hip arthroplasty are still matter of debate. Serum markers have been assessed as objective method to quantify muscle damage after surgery but in literature ambiguous results have been reported. The aim of this prospective randomized study was to: 1) compare serum markers elevation between a minimally invasive direct anterior approach (DAA) and a direct lateral approach (DLA); 2) to establish a correlation between serum markers increase and other perioperative variables. HYPOTHESIS: A lesser elevation of markers could be found in patients who underwent a minimally invasive DAA. PATIENTS AND METHODS: Seventy patients were enrolled and randomly divided in two groups according to the type of the approach. All patients were treated with the same implant by the same surgeon and received the same rehabilitation protocol. Demographic data, preoperative Harris Hip Score (HHS) and operative time were recorded. Myoglobin, creatine kinase MB (CK-MB), troponin I, C-reactive protein (CRP), haemoglobin (HB) and pain levels were measured pre- and postoperatively. RESULTS: Mean postoperative rise were 524.9±134.6 and 667.8±409.5 for myoglobin, 4.8±2.5 and 6.6±3.7 for CK-MB, and 16.9±5.3 and 15.4±6.4 for PCR, in DAA and DLA groups, respectively. In both groups, postoperatively values were significantly higher than preoperatively (p<0.05). Comparing the two groups, no significant differences in serum markers elevations were found. A significantly lower postoperative pain was found in DAA group than in DLA group (2.9 vs. 4.2 and 2.7 vs. 3.6 in second and third day, respectively (p<0.05)). No significant correlation was present between the serum marker elevations and age, BMI, HHS, operative time, HB or pain levels (p>0.05). CONCLUSION: Serum markers of muscle damage and inflammation increased in the postoperative period without significant differences between DAA and DLA, even though overall trend was higher in DLA group. The DAA group had significantly lower levels of postoperative pain. No significant correlation between pain and serum markers levels was found. LEVEL OF EVIDENCE: I; randomized study.

Arthroscopic vs open ankle arthrodesis: A prospective case series with seven years follow-up.

BACKGROUND: The osteoarthritis of the ankle, although less common than other joints, is associated with severe functional limitation. Surgical options are ankle arthroscopic debridement, osteotomies, ankle arthrodesis and ankle arthroplasty. Ankle arthroplasty is increasingly used thanks to the new implants design, but ankle arthrodesis still represents the most used technique and it can be performed arthroscopically or with an open procedure. AIM: To compare mid-term results of arthroscopic vs open ankle arthrodesis of patients affected by end-stage ankle arthritis. METHODS: This study enrolled 23 patients, which underwent ankle arthrodesis. The patients were divided into 2 groups: group A (open procedure; n = 11) and group B (arthroscopic procedure, n = 12), the two groups were homogeneous with regard to age and body mass index (P = 0.347). The American Orthopaedic Foot and Ankle score (AOFAS), Freiburg Ankle score (FAS) and visual analogue scale for pain intensity were evaluated preoperatively, at six months and at final follow-up of 7.6 years in group A and 7.3 years in group B (P = 0.364). RESULTS: Patients in the arthroscopic group showed better results at six-month follow-up compared to the open group at the AOFAS (group A, 62.2; group B, 78.5; P < 0.05) and the FAS (group A, 61.1; group B, 70.3; P = 0.015) scores. Pain relief was achieved in both groups at six-month follow-up (group A, 1.4; group B, 0.9; P = 0.162). Both open and arthroscopic groups showed improved clinical outcomes from baseline to final follow-up (P > 0.05). Hospital stay was shorter in group B than in group A (P = 0.001). More complications were reported in the open group than in the arthroscopic group (P = 0.459). CONCLUSION: The arthroscopic and the open arthrodesis are valid and safe options for the treatment of ankle arthritis on the basis of clinical outcomes at 7 years follow-up. Moreover, the arthroscopic treatment shows faster improvement at six-month follow-up in comparison with the open group.

Did the prevalence of suprascapular neuropathy in professional volleyball players decrease with the changes occurred in serving technique?

Objectives: Suprascapular neuropathy is more frequent in volleyball as compared to other overhead sports. This study aims to report the actual prevalence of suprascapular neuropathy among elite volleyball players. The hypothesis is that becoming jump topspin serves the most common serving technique, suprascapular neuropathy reduced its frequency. Methods: A total of 82 professional players were enrolled in the study. The presence of symptoms and the type of serve preferably performed were investigated. The strength and trophicity of the supraspinatus and infraspinatus muscles were evaluated. Patients with positive clinical findings underwent MRI of the shoulder. Results: The jump topspin serve was found to be the most popular type of serve both in males and females. At physical examination, 9% of the males and 12% of the females presented with infraspinatus muscle hypotrophy. Each case was accompanied by external rotation weakness. None of them complained of pain or reduced performance when they played. MRI confirmed infraspinatus muscle atrophy in all subjects. Conclusion: A lower prevalence of suprascapular neuropathy was found as compared with that previously reported in the 1980s and 1990s. A reduction in the popularity of the float serve seems to be a possible explanation. Thus, the jump topspin serve could be safe for suprascapular neuropathy and associated injuries in volleyball. The findings of this study should be considered by athletes and coaches for the prevention of activity-related injuries.

Measurement technique for posterior tibial slope on radiographs can affect its relationship to the risk of anterior cruciate ligament rupture.

PURPOSE: The purpose of this study was to determine the most reliable radiographic measurement method to evaluate PTS as a risk factor for ACL reconstruction failure. METHODS: Patients who underwent ACL reconstruction or ACL revision reconstruction between January 2009 and December 2014 by a single surgeon were included. Fifty-two consecutive patients who underwent ACL revision reconstruction were compared to a random selection of 52 patients who underwent primary ACL reconstruction and a control group of 52 patients without ACL injury. ACL reconstruction was performed using either ipsilateral (primary) or contralateral (revision) quadrupled hamstring autograft. Lateral knee radiographs were evaluated using three methods: (1) longitudinal axis, (2) anterior tibial cortex axis, and (3) posterior tibial cortex. RESULTS: A significant difference was found between subjects who underwent ACL reconstruction and control knees (6.79° vs. 5.31°, p = 0.046) using the posterior tibial cortex method. No other statistical significance was found between groups. A multiple linear regression analysis found that the PTS as measured by any method was not affected by the patient's age, sex, height, weight, and BMI. All methods of measurement for PTS demonstrated excellent (ICC > 0.90) intra-rater and inter-rater reliability, but only the posterior tibial cortex method maintained excellent intra-rater and inter-rater reliability (ICC > 0.90) when evaluating patients with ACL revision reconstruction. CONCLUSIONS: The posterior tibial cortex measurement is the most reliable method for analyzing the PTS on lateral knee radiographs in patients undergoing ACL revision reconstruction.

Acute kidney failure after total knee arthroplasty revision with antibiotic-impregnated cement spacer.

Gentamicin-impregnated cement beads and spacers are frequently used in case of infective complications after Total Knee Arthroplasty (TKA). A great number of studies in the literature demonstrated that the local administration of gentamicin produces high local antibiotic levels but low serum and urine gentamicin concentrations. Gentamicin-impregnated cement spacer can induce nephrotoxicity in patients presenting major renal impairment susceptibility. We report a case of acute renal failure using a gentamicin-impregnated block spacer. An 83-year-old woman underwent a gentamicinimpregnated bone-cement spacer implant because of an infected TKA removal. Three days later patient clinical status got worse reporting a decreased urine output and increasing C-reactive protein (CRP), Serum Creatinine (SCr) and Blood Urea Nitrogen (BUN). Because the symptoms could be related to the knee spacer lead us to the decision of gentamicin-impregnated cement spacer removal. The day following the removal procedure showed progressive improvement of general condition with evidence of SCr and BUN normalization. Gentamicin-impregnated cement spacer can induce nephrotoxicity in patients presenting major renal impairment susceptibility.

Mid-term CT assessment of bone healing after nanohydroxyapatite augmentation in open-wedge high tibial osteotomy.

BACKGROUND: The aim of the present study was to confirm the effectiveness of adding nanohydroxyapatite (NHA) to a heterologous bone graft in open-wedge high tibial osteotomy (OWHTO) by measuring the bone density via multislice computed tomography (CT) of the tibial osteotomy gap in a mid-term follow-up (five years). METHODS: Twenty-six patients undergoing OWHTO were randomly assigned to two groups: a pure graft group (Group A), in which the osteotomy gap was filled with only heterologous bone graft, and an NHA group (Group B), in which the osteotomy gap was filled with heterologous bone graft and NHA. CT was performed within one week of the operation, after two months, after 12 months and after five years. CT volume acquired in Hounsfield units (HU) was measured on three planes. RESULTS: The normal bone density was 110.2 ± 11.7 HU. The value of mean density at five years in Group A was 296.8 ± 81.8 HU, while in Group B, it was 202.2 ± 45.1 HU, showing a density more similar to normal bone and greater bone uniformity inside the osteotomy. The difference between the two groups was statistically significant (p < 0.05). Furthermore, both groups showed excellent mid-term clinical outcomes without significant differences. CONCLUSIONS: This study revealed that absorbability and bone formation at the osteotomy site in the NHA group was significantly higher as compared with the pure graft group at five years postoperatively.

Detection of α-defensin in synovial fluids by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry as an innovative and cost-effective assay for improved definition of periprosthetic joint infections.

RATIONALE: Detection of α-defensins in synovial fluid is gaining more and more interest in the field of correct diagnosis of periprosthetic joint infections (PJIs). At present, they can be assessed by a quantitative enzyme-linked immunosorbent assay which is expensive and time-consuming and by a qualitative lateral flow immunoassay which is rapid but quite expensive and whose clinical sensitivity is debated. Thus, developing an alternative rapid, accurate, and low-cost assay for α-defensins is important to make α-defensins actionable as novel key clinical markers. METHODS: Synovial fluid (SF) samples were obtained from 18 patients undergoing revision of primary joint arthroplasty. Of these, eight met the 2013 Musculoskeletal Infection Society (MSIS) criteria for PJIs, the remaining were classified as aseptic failure. Microbiological analysis and Synovasure assays were carried out on all samples. Sample preparation and the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) settings were adjusted to detect human neutrophil peptide (HNP)-1, -2 and -3 and to obtain optimal results in term of sensitivity and stability. RESULTS: MALDI-TOF MS was able to detect HNPs in SF from septic patients. No signals for HNPs were detected in SF from aseptic failure. The limits of detection (LOD) were 2.5 and 1.25 µg/mL for HNP-2 and HNP-1, respectively. The turnaround time of the analysis is 20 min, and SF samples are stable at -20°C for up to 3 days. Assay sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were 100% for all parameters. On the same SF samples, the Synovasure assay showed lower sensitivity specificity, and PPV and NPV of 87.5%, 90%, 87.5% and 90%, respectively. Microbiological analysis of SF confirmed the presence of bacteria only in SF MSIS-positive patients. CONCLUSIONS: The reported MALDI-TOF MS assay was able to detect and differentiate HNPs in SF samples and showed a slightly better diagnostic accuracy than the Synovasure assay.