The integration of titanium (Ti)-based implants with bone is limited, resulting in implant failure. This lack of osteointegration is due to the foreign body response (FBR) that occurs after the implantation of biodevices. The process begins with protein adsorption, which is governed by implant surface properties, e.g., chemistry, charge, wettability, and/or topography. The distribution and composition of the protein layer in turn influence the recruitment, differentiation, and modulation of immune and bone cells. The subsequent events that occur at the bone-material interface will ultimately determine whether the implant is encapsulated or will integrate with bone. Despite the numerous studies evaluating the influence of surface properties in the various stages of the FBR, the factors that affect tissue-material interactions are often studied in isolation or in small correlations due to the technical challenges involved in assessing them in vitro or in vivo. Consequently, the influence of protein conformation on the Ti bone implant surface design remains an unresolved research question. The objective of this review is to comprehensively evaluate the existing literature on the effect of surface parameters of Ti and its alloys in the stages of FBR, with a particular focus on protein adsorption and osteoimmunomodulation. This evaluation aims to systematically describe these effects on bone formation.

UNASSIGNED: Synthetic grafts have been used for a number of years in anterior cruciate ligament (ACL) reconstruction surgery. One of the more recent additions to the stable of synthetic ligaments is the Ligament Augmentation and Reconstruction System (LARS) ligament.
UNASSIGNED: To analyze the biomechanics and histology of LARS grafts retrieved due to failure of the device.
UNASSIGNED: Descriptive laboratory study.
UNASSIGNED: A total of 22 LARS ligament grafts that were explanted from patients were sent for analysis. Five new, unused samples of the standard LARS ACL graft were also analyzed. Biomechanical testing was performed: ultimate tensile force, force versus displacement, and stress versus strain were recorded. Histopathological examination was performed looking for degree of fibrous tissue ingrowth as well as the presence of a foreign body reaction.
UNASSIGNED: Of the 22 grafts retrieved, 14 were used for ACL grafts, 1 for a lateral collateral ligament graft, 2 for medial collateral ligament grafts, 4 for gluteal tendon augmentation, and 1 for a supraspinatus augmentation. A severe foreign body reaction was found in 86% of the grafts (18/22) and a mild foreign body reaction in the remaining 14% (4/22). Tissue ingrowth was minimal in the majority of ACL grafts; the other grafts showed moderate tissue ingrowth. Maximal tensile force was significantly higher for the new ACL grafts (mean ± SD, 1667 ± 845 N) compared with the retrieved grafts (897 ± 395 N; P < .05).
UNASSIGNED: This study demonstrated that the vast majority of retrieved LARS artificial ligaments had a florid foreign body reaction. There was minimal tissue ingrowth in ACL grafts and moderate ingrowth in other grafts. Retrieved grafts had a decreased ultimate tensile force, which increased their risk of rupture.
UNASSIGNED: Surgeons should be cautious in choosing to use these grafts in reconstructive surgery for patients.

To compare histologically the percentage of bone formation 12-20 weeks after ridge augmentation using 2 different techniques. Tooth loss is associated with 3-dimensional bone remodeling and ridge atrophy. Ridge preservation procedures can prevent alveolar bone volume loss. Different techniques and materials are used to preserve the alveolar ridge. Computer-generated randomization software was used to assign 2 ridge preservation techniques for 11 extraction sites. In group I, type I bovine Achilles tendon collagen plugs with bioactive resorbable calcium apatite crystals (CPCAC) were placed, and in group II, cortico-cancellous bone chips (CCBC) mix and an expanded polytetrafluoroethylene (ePTFE) barrier membrane were placed. The histomorphometric studies were performed using a computer-based image analysis system (ImageJ 1.4, National Institute of Health, Bethesda, Md) to calculate the pixel area of bone tissue and the remaining bone graft material. The histomorphometric data were analyzed using a Student t test to compare the measurements between the 2 experimental groups. This parametric statistical test was employed to determine if there were any statistically significant differences in the quantitative histological parameters between the groups. The sockets that received CPCAC showed a lower (31.89%) percentage of native bone surface area compared with the CCBC group (43.87%). However, the difference was not statistically significant (P < .05). In addition, the CPCAC group showed evidence of foreign-body reaction. The CCBC graft covered with an ePTFE barrier may induce more bone formation with minimal inflammation in an extraction socket compared with a collagen plug with calcium apatite crystals. In addition, histological analysis of the CPCAC graft showed evidence of foreign-body reaction, which indicates a negative clinical impact.

A cascade of reactions known as the foreign body response (FBR) follows the implantation of biomaterials leading to the formation of a fibrotic capsule around the implant and subsequent health complications. The severity of the FBR is driven mostly by the physicochemical characteristics of implanted material, the method and place of implantation, and the degree of immune system activation. Here we present an in vitro model for assessing new materials with respect to their potential to induce a FBR in the peritoneum. The model is based on evaluating protein sorption and cell adhesion on the implanted material. We tested our model on the free-standing films prepared from hyaluronan derivatives with different hydrophobicity, swelling ratio, and rate of solubilization. The proteomic analysis of films incubated in the mouse peritoneum showed that the presence of fibrinogen was driving the cell adhesion. Neither the film surface hydrophobicity/hydrophilicity nor the quantity of adsorbed proteins were decisive for the induction of the long-term cell adhesion leading to the FBR, while the dissolution rate of the material proved to be a crucial factor. Our model thus helps determine the probability of a FBR to materials implanted in the peritoneum while limiting the need for in vivo animal testing.

We aimed to investigate the clinical manifestations, radiological findings, and therapeutic outcome of treatment for patients with surgically confirmed foreign body reaction following an Achilles tendon repair using non-absorbable suture material. Eight consecutive patients who were confirmed as having an intra-tendinous suture foreign body reaction in the histopathological report were enrolled in this study. Medical records of all patients in terms of clinical and radiological features were retrieved. Also, the outcome of treatment was evaluated at a follow-up of at least 12 months. All the patients complained of pain and a palpable mass around a previous surgical site at mean 25.1 months (range, 4-72 months) after the initial surgery. Magnetic resonance imaging (MRI) or ultrasound were used to detect the lesion. All the patients underwent surgical excision of foreign body reaction tissue and primary repair using absorbable suture material. After the treatment, the wounds were healed completely in all, and the average FAOS (foot and ankle outcome score) was 91.32 at mean follow-up for 22.4 months. In conclusion, intra-tendinous suture reaction is a rare complication following an Achilles tendon repair using nonabsorbable suture material, but it can be treated adequately with only surgical excision of foreign body reaction tissue and primary repair using absorbable suture material.

UNASSIGNED: Polyactide (PLA) barrier is one of the most commonly used materials to prevent the formation of postoperative adhesion. Even though previous studies supported the anti-adhesion efficacy of PLA barrier, there have been limited reports focusing on the associated foreign body reaction. We sought to investigate the potential complication of PLA barrier placement that could lead to unnecessary intervention.This is a retrospective study of colorectal cancer patients with laparoscopic surgery. Cases with stage IV unresectable disease, poor Eastern Cooperative Oncology Group Performance, death within 3 months after the surgery, and insufficient record were excluded. A total of 296 cases were identified in our study and 220 patients received PLA film placement. We compared the incidence of foreign body reaction between the patients with and without PLA film.Among PLA film group, 16 cases had signs of local recurrence on the follow-up image studies. The subsequent operation found 10 patients had no cancerous lesions but only foreign-body-associated granulomas. The incidence of foreign body reaction mimicking local recurrence on image study was 4.5% with high false positive rate of 62.5% on positron emission tomography scan in patients with PLA film. There were only 2 cases without the antiadhesive barrier developed signs of recurrence during active surveillance. Both cases were later confirmed to have malignant peritoneal seeding.The PLA film was associated with rare foreign body reaction that could interfere the accuracy of follow-up program and result in unnecessary surgical intervention. Hence, we recommend avoiding the use of the PLA barrier.

The evaluation of the natural history prevalence of adverse local tissue reactions (ALTRs) using MRI has focused only on metal-on-metal (MoM) bearing surfaces without comparison to nonMoM bearing surfaces.
To determine (1) the longitudinal changes and differences in blood metal ion levels in patients with hip resurfacing arthroplasty (HRA), ceramic-on-ceramic (CoC) THA, and metal-on-polyethylene (MoP) THA compared with those undergoing ceramic-on-polyethylene (CoP) THA; (2) how the longitudinal change of synovial reaction classification in patients with HRA, CoC THA, and MoP THA compares with those undergoing CoP THA, and whether there is an association between the presence of an ALTR or metallosis on MRI with corresponding patient-reported outcomes, or the presence of capsular dehiscence; and (3) differences in blood metal ion levels between patients undergoing HRA with an ALTR or metallosis on MRI and those with HRA without these conditions.
Between March 2014 and February 2019, 22,723 patients underwent primary HRA and THA at one center. Patients received an HRA based on their desired athletic level after surgery and the presence of normal acetabular and proximal femoral bone morphology without osteopenia or osteoporosis. Two percent (342 of 22,723) of patients were contacted to participate, and 71% (243 of 342 hips in 206 patients) were enrolled for analysis at baseline. The patients underwent arthroplasty for degenerative joint disease, and 25 patients withdrew over the course of the study. We included patients who were more than 1 year postarthroplasty. All participants had an MRI examination and blood serum ion testing and completed a Hip Disability and Osteoarthritis Outcome Score survey annually for four years (baseline, year 1, year 2, year 3). Morphologic and susceptibility-reduced MR images were evaluated by a single radiologist not involved in the care of patients for the presence and classification of synovitis (Gwet AC1: 0.65 to 0.97), synovial thickness, and volume (coefficient of repeatability: 1.8 cm3). Linear mixed-effects models were used to compare the mean synovial thickness, synovial volume, and Hip Disability and Osteoarthritis Outcome Score subscales between bearing surfaces at each timepoint and within each bearing surface over time. Marginal Cox proportional hazards models were used to compare the time to and the risk of developing ALTR only, metallosis only, and ALTR or metallosis between bearing surfaces. All models were adjusted for age, sex, BMI, and length of implantation based on known confounders for hip arthroplasty. Adjustment for multiple comparisons was performed using the Dunnett-Hsu method.
Patients with unilateral HRA had higher cobalt and chromium serum ion levels (baseline: 1.8 ± 0.8 ppb, year 1: 2.0 ± 1.5 ppb, year 2: 2.1 ± 1.2 ppb, year 3: 1.6 ± 0.7 ppb) than those with unilateral CoP bearings (baseline: 0.0 ± 0.1 ppb, year 1: 0.1 ± 0.3 ppb, year 2: 0.0 ± 0.2 ppb, year 3: 0.0 ± 0.0 ppb) at all timepoints (p < 0.001 for each time point). More patients who received an HRA developed ALTR or metallosis on MRI than did patients with CoP bearings (hazard ratio 4.8 [95% confidence interval 1.2 to 18.4]; p = 0.02). There was no association between the longitudinal change of synovial reaction to ALTR or metallosis on MRI with patient-reported outcomes. In addition, there was no association between the presence of dehiscence at baseline and the subsequent development of ALTR or metallosis, as seen on MRI. There were elevated cobalt (4.7 ± 3.5 ppb) and chromium (4.7 ± 2.6 ppb) serum levels in patients with unilateral HRA who had an ALTR or metallosis present on MRI at year 1 compared with patients without an ALTR or metallosis on MRI (cobalt: 1.8 ± 1.0 ppb, mean difference 4.7 ppb [95% CI 3.3 to 6.0]; p < 0.001; chromium: 2.3 ± 0.5 ppb, mean difference 3.6 ppb [95% CI 2.2 to 5.0]; p < 0.001) as well as for chromium at year 3 (3.9 ± 2.4 ppb versus 2.2 ± 1.1 ppb, mean difference 1.3 ppb [95% CI 0.3 to 2.4]; p = 0.01).
We found a higher proportion of ALTR or metallosis on MRI in patients with HRA compared with patients with CoP, even when patient self-assessed symptomatology of those with an ALTR or metallosis on MRI was not different than the absence of these features. MRI detected ALTRs in high-function patients, emphasizing that an annual clinical assessment dependent on survey or blood ion testing alone may not detect soft tissue complications. The results of this study are in line with prior consensus recommendations of using MRI as part of a routine follow-up protocol for this patient population.
Level III, therapeutic study.

Evaporation of phosphate species during thermal treatment (> 400 °C) of calcium phosphates leads to the formation of an alkaline layer on their surface. The aim of this study was to evaluate the hypothesis that the biological response of thermally treated calcium phosphates is modified by the presence of such an alkaline layer on their surface. For this purpose, 0.125-0.180 mm α- and β-tricalcium phosphate (TCP) granules were obtained by crushing and size classification, with some being subjected to thermal treatment at 500 °C. The four types of granules (α-TCP, β-TCP, α-TCP-500 °C, and β-TCP-500 °C) were implanted subcutaneously and orthotopically in rats. Sham operations served as control. Subcutaneously, α-TCP and β-TCP induced significantly more multinucleated giant cells (MNGCs) than calcined granules. Most of the induced MNGCs were TRAP-negative, CD-68 positive and cathepsin K-negative, reflecting a typical indication of a reaction with a foreign body. The vessel density was significantly higher in the α-TCP and β-TCP groups than it was in the α-TCP-500 °C and β-TCP-500 °C groups. In the femur model, β-TCP-500 °C induced significantly more new bone formation than that induced by β-TCP. The granule size was also significantly larger in the β-TCP-500 °C group, making it more resistant to degradation than β-TCP. The MNGC density was higher in the α-TCP and β-TCP groups than in the α-TCP-500 °C and β-TCP-500 °C groups, including cathepsin-positive, CD-68 positive, TRAP-positive and TRAP-negative MNGCs. In conclusion, this study confirms that the biological response of calcium phosphates was affected by the presence of an alkaline layer on their surface. Thermally-treated α-TCP and β-TCP granules produced significantly fewer MNGCs and were significantly less degraded than non-thermally-treated α-TCP and β-TCP granules. Thermally treating α-TCP and β-TCP granules shifts the reaction from a foreign body reaction towards a physiological reaction by downregulating the number of induced MNGCs and enhancing degradation resistance.

Polymer-coats may peel-off the surface of catheters and devices during endovascular procedures and might lead to brain inflammatory foreign-body reactions.
We conducted a retrospective, descriptive, single-centre study including all patients with symptomatic intracranial oedematous and contrast-enhancing lesions after any neurointerventional procedure performed in our hospital between 2013 and 2019.
From a total of 7446 neurointerventional procedures, 11 cases were identified (9 female, 2 male, median age 47 year-old), with an incidence of 0.14 %. The procedures were therapeutic in all: ten aneurysm embolization/isolation, one acute ischaemic stroke recanalization. Intracranial coils, stent or both were placed in all. Symptoms appeared during the following one day to fourteen months (median of 4.2 weeks). Brain MRI showed oedematous, contrast-enhancing lesions scattered through the vascular territory of the canalized vessel. Brain biopsy confirmed the diagnosis in one case and was supportive in another one. Eight patients received immunosuppression. No treatment was started in two. After a median time of follow-up of 3.5 years, five patients are totally asymptomatic. One patient presents slight weakness. Four patients have remote symptomatic seizures, but they have comorbid lesions (previous stroke, intracranial haemorrhage, biopsy needle-track\'s gliosis). Follow-up MRI showed significant improvement in all the cases, with complete resolution in five. Non-symptomatic lesion fluctuation was observed in three cases. Two patients experienced symptomatic rebounds.
Intracranial embolic foreign-body symptomatic reactions are uncommon complications of neurointerventional procedures. Diagnostic angiographies might have lower risk of polymer-embolization than therapeutic procedures. This entity\'s early recognition enables making proper diagnosis and treatment decisions.

Button batteries are the second most frequently-ingested foreign bodies and can lead to serious clinical complications within hours of ingestion. The purpose of this study was to analyze the outcomes of 14 children with button batteries lodged in the upper gastrointestinal tract.Totally 14 children with button batteries lodged in the upper gastrointestinal tract were included. The diagnosis was made primarily by the history of button battery ingestion, physical examination and chest-abdomen X-ray examination.The button batteries lodged in the esophagus were removed by esophagoscope, and those in the gastrointestinal tract were under observation. Among 10 children with batteries in the first esophageal stenosis, 9 were cured and 1 suffered from tracheoesophageal fistula. One case of battery in the second esophageal stenosis was dead due to intercurrent aortoesophageal fistula. Two cases of batteries in the third esophageal stenosis were cured after removal, and 1 case of the battery in the gastrointestinal tract discharged spontaneously.Ingested button batteries are mainly lodged in the esophageal stenoses and are easy to cause esophageal injury and severe complications. Early detection, prompt treatment, strengthening observation and regular follow-up after discharge may help to decrease the incidence of complications and improve the outcomes.