Prospective evaluation of ultrasound features of magnesium-based bioabsorbable screw resorption in pediatric fractures.

OBJECTIVE: Bioabsorbable magnesium-based alloy screws release gas upon resorption. The resulting findings in the adjacent soft tissues and joints may mimic infection. The aim of the study was to evaluate the ultrasound (US) findings in soft tissues and joints during screw resorption. METHODS: Prospectively acquired US studies from pediatric patients treated with magnesium screws were evaluated for screw head visibility, posterior acoustic shadowing, twinkling artifact, foreign body granuloma, gas (soft tissue, intra-articular), alterations of the skin and subcutaneous fat, perifascial fluid, localized fluid collections, hypervascularization, and joint effusion. RESULTS: Sixty-six US studies of 28 pediatric patients (nfemale = 9, nmale = 19) were included. The mean age of the patients at the time of surgery was 10.84 years; the mean time between surgery and ultrasound was 128.3 days (range = 6-468 days). The screw head and posterior acoustic shadowing were visible in 100% of the studies, twinkling artifact in 6.1%, foreign body granuloma in 92.4%, gas locules in soft tissue in 100% and intra-articular in 18.2%, hyperechogenicity of the subcutaneous fat in 90.9%, cobblestoning of the subcutaneous fat in 24.2%, loss of normal differentiation between the epidermis/dermis and the subcutaneous fat in 57.6%, localized fluid collection in 9.9%, perifascial fluid in 12.1%, hypervascularization in 27.3%, and joint effusion in 18.2%. CONCLUSION: US findings in pediatric patients treated with magnesium screws strongly resemble infection, but are normal findings in the setting of screw resorption. CLINICAL RELEVANCE STATEMENT: Bioabsorbable magnesium-based alloy screws release gas during resorption. The resulting US findings in the adjacent soft tissues and joints in pediatric patients may mimic infection, but are normal findings. KEY POINTS: • Bioabsorbable magnesium-based alloy screws release gas upon resorption. • The resulting ultrasound findings in children's soft tissues and joints closely resemble those of soft tissue infection or osteosynthesis-associated infection. • Be familiar with these ultrasound findings in order to avoid inadvertently misdiagnosing a soft tissue infection or osteosynthesis-associated infection.

Are Absorbable Plates More Resistant to Infection Than Titanium Implants? An Experimental Pre-Clinical Trial in Rabbits.

Background: Infection of orthopaedic implants after internal fixation of bone fractures remains a major complication with occasionally devastating consequences. Recent studies have reported that the use of absorbable materials, instead of metallic ones, may lead to a lower incidence of postoperative infection. In this experimental pre-clinical animal study, we compared the infection rate between absorbable implants consisting of copolymers composed from trimethylene carbonate, L-polylactic acid, and D, L-polylactic acid monomers, and titanium implants after the inoculation of a pathogenic microorganism. Material and Methods: We used an experimental implant-related infection model in rabbits. Sixty animals were randomly and equally divided into two groups. In all animals, the right femur was exposed via a lateral approach and a 2.5 mm two-hole titanium plate with screws (Group A), or a two-hole absorbable plate and screws (Group B), were applied in the femoral shaft. Afterwards, the implant surface was inoculated with Pseudomonas Aeruginosa at a concentration of 2 × 108 CFU/mL. The primary outcome was the comparison of the incidence of developed infection between the two groups. The wound condition was monitored on a daily basis and radiographies were obtained at 12 weeks postoperatively. Infection-related laboratory markers (white blood cell count, erythrocyte sedimentation rate, and C-reactive protein values) were assessed at 3, 6, and 16 weeks postoperatively. Histologic analysis and cultures of tissue samples were also performed to evaluate the presence of infection. Results: Clinical and laboratory signs of infection were evident in 11 rabbits in Group A (36.7%), and 4 in Group B (13.3%). The difference between the groups was statistically significant (p = 0.04). Five animals in Group B (16.7%) had clinical and histologic signs of a foreign-body reaction with significantly elevated CRP and ESR values but no simultaneous presence of infection was identified (p = 0.04). Bone remodelling with thickening of the periosteum and surrounding sclerosis was demonstrated radiologically in animals developing infection or foreign-body reactions. Conclusions: Absorbable plates and screws show lower susceptibility to infection compared to titanium ones. However, their application is associated with foreign-body reaction and the potential need for a second surgical intervention.

Treatment of traumatic cranial fracture with sonic activated polymer pins and plates resorbable implants in a dog.

INTRODUCTION: The case report describes the use of ultrasound-activated resorbable implants for surgical repair of comminuted cranial fractures in a 10 years old medium sized mix-breed dog being injured from a horse kick.

INTRODUCTION: Ce rapport de cas décrit l'utilisation d'implants résorbables activés par ultrasons pour la réparation chirurgicale de fractures crâniennes comminutives chez un chien de race moyenne âgé de 10 ans, blessé par un coup de pied de cheval.

Efficacy and Safety of Beta-Tricalcium Phosphate/Polylactic-Co-Glycolic Acid for Implantation of Bone Defects.

INTRODUCTION: Bone defects are often observed after surgery for fractures and bone tumors. Their treatment is technically difficult and sometimes results in negative clinical and economic outcomes. To repair bone defects, a bone graft is implanted by selecting a transplant material from an autologous or artificial bone. Each method has its advantages and disadvantages. Compared to the gold standard of autologous bone graft, bone graft substitutes are not limited by the amount of harvested graft and avoid complications at the donor site. ORB-03 is a new cotton-like bone graft substitute composed of beta-tricalcium phosphate (ß-TCP) and a bioabsorbable polymer, polylactic-co-glycolic acid (PLGA). ORB-03 is easy to mold and can fill various bone defect shapes, and its three-dimensional microfiber scaffold can enhance the differentiation of osteoblasts and promote osteogenesis. We investigated the efficacy, ease of handling, and safety of ORB-03 as a bone graft substitute. A multicenter, open-label, single-group study was conducted at six institutions. METHODS: Between July 2018 and August 2019, 60 patients with bone defects caused by fracture, benign tumors, or an iliac donor site from bone harvesting were enrolled in this study; 54 patients were finally included for the safety analysis and 48 patients for the image analysis. During surgery, ORB-03 was mixed with the patient's blood and molded into a bone defect. To evaluate the efficacy of ORB-03, radiography and computed tomography (CT) were performed at intervals until 24 weeks after surgery. RESULTS: The effective rate and its accurate bilateral 95% confidence interval (CI) were calculated based on the efficacy criteria at 24 weeks postoperatively. The ease with which ORB-03 could be handled in surgery was evaluated. Adverse events that occurred after surgery were evaluated, and those associated with ORB-03 were examined. Bone fusion was good in all cases, and the radiography and CT effective rates were 100.0% and 91.5%, respectively. Handling was easy in all cases. There were four adverse events, none of which were clinically problematic. CONCLUSIONS: ORB-03 was found to be easy to handle, safe, and effective as a bone graft substitute for bone defects.

Bioresorbable Poly (L-Lactic Acid) Flow Diverter Versus Cobalt-Chromium Flow Diverter: In Vitro and In Vivo Analysis.

BACKGROUND: Permanent metallic flow diverter (FD) implantation for treatment of intracranial aneurysms requires antiplatelet therapy for an unclear duration and restricts postprocedural endovascular access. Bioresorbable FDs are being developed as a solution to these issues, but the biological reactions and phenomena induced by bioresorbable FDs have not been compared with those of metallic FDs. METHODS: We have developed a bioresorbable poly (L-lactic acid) FD (PLLA-FD) and compared it with an FD composed of cobalt-chromium and platinum-tungsten (CoCr-FD). FD mechanical performance and in vitro degradation of the PLLA-FD were evaluated. For in vivo testing in a rabbit aneurysm model, FDs were implanted at the aneurysm site and the abdominal aorta in the PLLA-FD group (n=21) and CoCr-FD group (n=15). Aneurysm occlusion rate, branch patency, and thrombus formation within the FD were evaluated at 3, 6, and 12 months. Local inflammation and neointima structure were also evaluated. RESULTS: Mean strut, porosity, and pore density for the PLLA-FD were 41.7 µm, 60%, and 20 pores per mm2, respectively. The proportion of aneurysms exhibiting a neck remnant or complete occlusion did not significantly differ between the groups; however, the complete occlusion rate was significantly higher in the PLLA-FD group (48% versus 13%; P=0.0399). Branch occlusion and thrombus formation within the FD were not observed in either group. In the PLLA-FD group, CD68 immunoreactivity was significantly higher, but neointimal thickness decreased over time and did not significantly differ from that of the CoCr-FD at 12 months. Collagen fibers significantly predominated over elastic fibers in the neointima in the PLLA-FD group. The opposite was observed in the CoCr-FD group. CONCLUSIONS: The PLLA-FD was as effective as the CoCr-FD in this study and is feasible for aneurysm treatment. No morphological or pathological problems were observed with PLLA-FD over a 1-year period.

Prospective Evaluation of Magnetic Resonance Imaging Features of Magnesium-Based Alloy Screw Resorption in Pediatric Fractures.

BACKGROUND: The resorption of magnesium-based alloy bioabsorbable screws results in the release of hydrogen gas, which can mimic infection and enter the growth plate. The screw itself and the released gas may also affect image quality. OBJECTIVE: The evaluation of magnetic resonance imaging (MRI) findings during the most active phase of screw resorption is the objective, with particular focus on the growth plate and to assess for the presence of metal-induced artifacts. MATERIAL AND METHODS: In total, 30 prospectively acquired MRIs from 17 pediatric patients with fractures treated with magnesium screws were assessed for the presence and distribution of intraosseous, extraosseous, and intra-articular gas; gas within the growth plate; osteolysis along the screw; joint effusion; bone marrow edema; periosteal reaction; soft tissue edema; and metal-induced artifacts. RESULTS: Gas locules were found in the bone and soft tissues in 100% of the examinations, intra-articular in 40%, and in 37% of unfused growth plates. Osteolysis and the periosteal reaction were present in 87%, bone marrow edema in 100%, soft tissue edema in 100%, and joint effusion in 50% of examinations. Pile-up artifacts were present in 100%, and geometric distortion in 0% of examinations. Fat suppression was not significantly impaired in any examination. CONCLUSIONS: Gas and edema in the bone and soft tissues are normal findings during the resorption of magnesium screws and should not be misinterpreted as infection. Gas can also be detected within growth plates. MRI examinations can be performed without metal artifact reduction sequences. Standard fat suppression techniques are not significantly affected.

SX-ELLA biodegradable stent for benign oesophageal strictures: a systematic review and proportion meta-analysis.

BACKGROUND: This systematic review aimed to analyse the use of the SX-ELLA biodegradable stent (BDS) for benign oesophageal strictures through the assessment of clinical and technical success, differences in pre- and post-BDS insertion dysphagia scores, rates of stent migration, and safety. METHODS: A systematic review was reported according to PRISMA guidelines, with a prospectively registered protocol. The databases PubMed, Embase, SCOPUS, and ClinicalTrials.gov were searched up to March 2022. Studies assessing the use of the SX-ELLA BDS in adults with benign oesophageal strictures were included. A pooled data analysis was conducted to analyse the clinical and technical success associated with BDS use, rate of stent migration, and safety. RESULTS: Of the 1509 articles identified, 16 studies treating 246 patients were eligible for inclusion. BDS was clinically successful in 41.9% of cases (95% CI = 35.7 - 48.1%), defined as those who experienced complete symptom resolution following BDS insertion. Technical success was achieved in 97.2% of patients (95% CI = 95.1 - 99.3%). A pooled analysis concluded a decrease in mean dysphagia score of 1.8 points (95% CI = 1.68 - 1.91) following BDS insertion. Re-intervention was required in 89 patients (36.2%, 95% CI = 30.2 - 42.2%), whilst stent migration occurred in 6.5% of patients (95% CI = 3.4 - 9.6%). A total of 37 major clinical complications related to BDS insertion were reported (15.0%, 95% CI = 10.5 - 19.5%). CONCLUSION: The pooled data analysis demonstrates the high technical and moderate clinical success of the SX-ELLA biodegradable stent, supporting its use for benign oesophageal strictures in adults. However, greater evidence is required for more robust conclusions to be made in terms of success when compared to alternative methods of intervention, such as endoscopic dilation.

Metallic screw fixation versus absorbable screw fixation after open reduction in treatment of distal tibial epiphyseal fractures in adolescents / 中华创伤骨科杂志

Objective:To compare the efficacy between metallic screw fixation and absorbable screw fixation after open reduction in the treatment of adolescent distal tibial epiphyseal fractures.Methods:A retrospective study was conducted to analyze the data of 82 patients with closed distal tibial epiphyseal fracture who had been admitted to Department of Pediatric Orthopedics, Shengjing Hospital Affiliated to China Medical University from January 2013 to December 2020. There were 61 males and 21 females (aged from 8 to 15 years), and 39 left sides and 43 right sides. The Salter-Harris classification: type Ⅱ in 25 cases, type Ⅲ in 8 cases, and type Ⅳ in 49 cases. They were divided into 2 groups according to different internal fixation methods. Group A (42 cases) was subjected to open reduction and metallic screw fixation and group B (40 cases) to open reduction and absorbable screw fixation. Preoperative data, operation time, total treatment cost and complications during follow-up were recorded and compared between the 2 groups. In both groups at the last follow-up, anteroposterior and lateral ankle radiographs were taken for radiographic evaluation of the injury to the distal tibial epiphysis and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was used to assess the ankle function.Results:The 2 groups were comparable because there were no significant differences in all their preoperative demographic data ( P>0.05). Group A was followed up for 18.0(16.0, 21.3) months while group B for 16.0(13.0, 20.0) months. The treatment cost for group A [27, 000 (25, 000, 33, 000) Yuan] was significantly higher than that for group B [23, 000 (19, 000, 27, 000) Yuan] ( P<0.05). The operation time was (112.4±34.3) min for group A and (101.0±41.1) min for group B, showing no significant difference ( P>0.05). The lateral distal tibial angle was 89.5 (88.0, 91.0)° on the affected side and 89.7°±1.8° on the unaffected sides in group A; it was 90.0 (88.3, 90.8)° on the affected side and 89.5°±1.8° on the unaffected side in group B. The anterior distal tibial angle was 81.9°±1.8° on the affected side and 81.8°±1.5° on the unaffected side in group A; it was 82.0 (81.0, 83.0)° on the affected side and 82.1°±2.2° on the unaffected side in group B. There was no significant difference in the above comparisons at the last follow-up in radiographic evaluation of the distal ankle joint between the affected and the unaffected sides in either group or between groups( P>0.05). There was a significant difference between the 2 groups in the rate of superficial skin infection [11.9% (5/42) versus 0% (0/40)] ( P<0.05), but there was no significant difference in the incidence of premature physeal closure between the 2 groups [11.9% (5/42) versus 5.0% (2/40)] ( P>0.05). The last follow-up revealed no significant difference in the AOFAS ankle-hindfoot score between group A [(90.6±4.9) points] and group B [(92.1±4.6) points] ( P>0.05). Conclusions:In the treatment of adolescent distal tibial epiphyseal fractures, compared with metallic screw fixation, absorbable screw fixation may lead to comparable efficacy in fixation, functional recovery and imaging evaluation, but no increased risk of premature physeal closure. Moreover, it spares the need for secondary surgical removal, and reduces operation time and treatment cost.

Osteointegration of PLLA/ß-TCP Biocomposite Anchors Used in Coracoid Transfer Procedures for Shoulder Instability: Quantitative Computed Tomography With a Minimum 2-Year Follow-up.

Background: Biocomposite anchors have been a popular choice for use in coracoid transfer procedures for shoulder instability and are hypothesized to allow bone ingrowth. Purpose: To quantitatively evaluate the osteointegration of 85% PLLA/15% ß-TCP biocomposite anchors used in the coracoid transfer procedure for shoulder instability. Study Design: Case series; Level of evidence, 4. Methods: We performed a retrospective case series of abstracted data from the records of 74 patients who underwent coracoid transfer procedures with biocomposite anchors. Computed tomography was performed at 24 months postoperatively. A total of 4 researchers independently reviewed the computed tomography images. The density (in Hounsfield unit [HU] values) of the anchor tunnels, glenoid, and subscapularis was assessed, and osteointegration of the anchor tunnels was evaluated with HU values, the quantitative ossification quality score (QOQS), and tunnel widening. Results: Included were 74 patients (58 male, 16 female), involving 76 shoulders and 124 biocomposite anchors. At ≥24-month follow-up, 72 of 124 (58.06%) anchor tunnels were classified as QOQS type 1, including 12 completely ossified tunnels and 60 almost completely ossified tunnels. Some degree of ossification (QOQS types 1-3) was observed in 118 (95.16%) anchor tunnels. Overall, 3 anchor tunnels were enlarged (QOQS type 5). The mean HU value of the anchor tunnels was 339.75, which was significantly higher than the preoperative HU value of the glenoid vault (262.19). Among the 124 anchor tunnels, 79 had HU values higher than their glenoid HU values, and 45 had lower HU values than their glenoid HU values. In the comparison of tunnel HU values at 12 versus ≥24 months, the HU value at ≥24 months was significantly higher. A total of 20 anchor tunnels widened. Conclusion: Among 124 anchor tunnels, 95.16% showed ossification, 58.06% were completely or nearly completely ossified, and 3 were enlarged. The HU value of the anchor tunnel increased over time.

[Minimally invasive osteotomy with absorbable screws in treating hallux valgus deformity].

OBJECTIVE: To evaluate clnical effect of minimally invasive osteotomy with absorbable screws in treating hallux valgus deformity. METHODS: Clnical data of 31 patients with hallux valgus deformity were retrospective analyzed from January 2019 to December 2020, and divided into absorbable screws group (17 patients) and titanium cannulated screw group (14 patients). In absorbable screws group, there were 1 male and 16 females aged from 32 to 72 years old with an average of (54.53±12.12) years old;6 patients on the left side, 5 on bilateral and 6 on the right side;1 patient was mild, 11 moderate and 5 severe;treated with minimally invasive osteotomy and fixation of absorbable screws. In titanium cannulated screw group, there were 2 males and 12 females aged from 18 to 71 years old with an average of (47.57±15.68) years old;4 patients on the left side, 4 on bilateral and 6 on the right side;1 patient was mild, 9 moderate and 4severe;treated with minimally invasive osteotomy and fixation of titanium cannulated screw. Complications between two groups were observed, changes of hallux valgus angle (HVA)and intermetatarsal angle (IMA)were detected and compared before and after operation at 12 months, American Orthopedic Foot and Ankle Society(AOFAS) and visual analogue scale(VAS) before and after operation at 12 months were also compared. RESULTS: All 31 patients were followed up from 13 to 20 months with an average of (16.61±2.47) months. Patients in absorbable screws group were followed up from 14 to 20 months with an average of (16.88±2.80) months, while patients in titanium cannulated screw group were followed up from 13 to 19 months with an average of (16.29±2.05) months;there was no difference between two groups(P>0.05). One patient in absorbable screws group occurred numbness around incision, 3 patients in titanium cannulated screw group occurred complications, including numbness around incision in 1 patient, skin irritation due to internal fixation in 1 patient, and recurrence in 1 case;there was no statistic difference between two groups (χ2=1.651, P=0.199). There were no statistic difference in HVA and IMA between two groups before and after operation at 12 months(P>0.05). There were no statistic difference between two groups in AOFAS and VAS before and after operation at 12 months(P>0.05). CONCLUSION: Compare with mainstream fixation with titanium hollow screw after minmally invasive osteotomy, fixation with absorbable screw could achieve comparable clinical outcome on the basis of images and function evaluation.

Local Drug Delivery Strategies for Glioblastoma Treatment.

Glioblastoma multiforme (GBM) is a brain tumor notorious for its malignancy. The key reason for the limited efficacy of standard treatment is the high recurrence rate of GBM, even after surgical resection. Hence, intensive postsurgical chemical therapies, such as the systemic delivery of various drugs and/or drug combinations, are typically followed after surgery. However, overcoming the blood-brain barrier by systemic administration to efficiently deliver drugs to the brain tumor remains a daunting goal. Therefore, various local drug delivery methods showing potential for improved therapeutic efficacy have been proposed. In particular, the recent application of electronic devices for the controlled delivery of chemotherapy drugs to GBM tissue has attracted attention. We herein review the recent progress of local drug delivery strategies, including electronics-assisted strategies, at the research and commercial level. We also present a brief discussion of the unsolved challenges and future research direction of localized chemotherapy methods for GBM.

Titanium or Biodegradable Osteosynthesis in Maxillofacial Surgery? In Vitro and In Vivo Performances.

Osteosynthesis systems are used to fixate bone segments in maxillofacial surgery. Titanium osteosynthesis systems are currently the gold standard. However, the disadvantages result in symptomatic removal in up to 40% of cases. Biodegradable osteosynthesis systems, composed of degradable polymers, could reduce the need for removal of osteosynthesis systems while avoiding the aforementioned disadvantages of titanium osteosyntheses. However, disadvantages of biodegradable systems include decreased mechanical properties and possible foreign body reactions. In this review, the literature that focused on the in vitro and in vivo performances of biodegradable and titanium osteosyntheses is discussed. The focus was on factors underlying the favorable clinical outcome of osteosyntheses, including the degradation characteristics of biodegradable osteosyntheses and the host response they elicit. Furthermore, recommendations for clinical usage and future research are given. Based on the available (clinical) evidence, biodegradable copolymeric osteosyntheses are a viable alternative to titanium osteosyntheses when applied to treat maxillofacial trauma, with similar efficacy and significantly lower symptomatic osteosynthesis removal. For orthognathic surgery, biodegradable copolymeric osteosyntheses are a valid alternative to titanium osteosyntheses, but a longer operation time is needed. An osteosynthesis system composed of an amorphous copolymer, preferably using ultrasound welding with well-contoured shapes and sufficient mechanical properties, has the greatest potential as a biocompatible biodegradable copolymeric osteosynthesis system. Future research should focus on surface modifications (e.g., nanogel coatings) and novel biodegradable materials (e.g., magnesium alloys and silk) to address the disadvantages of current osteosynthesis systems.

Radiographic features of magnesium-based bioabsorbable screw resorption in paediatric fractures.

BACKGROUND: Resorption of magnesium-based alloy bioabsorbable screws produces hydrogen gas, which can be mistaken as a sign of infection and may affect the physis or fixed bone fragment. OBJECTIVE: We evaluated the temporal and spatial occurrence of gas and the occurrence of a breakage of the fixed bone fragment or screw following magnesium screw fixation. MATERIALS AND METHODS: Radiographs of paediatric patients treated with magnesium screws were retrospectively reviewed. Temporal occurrence and distribution of gas in the bone, the physis and soft tissues, breakage of the screw or fixed bone fragment and joint effusion were assessed. RESULTS: One hundred and three radiographs in 35 paediatric patients were reviewed (mean age: 10.6 years). Follow-up ranged from 1 to 730 days. Gas in the bone increases up to week 5, remains constant up to week 16 and then decreases. Gas in soft tissues, intra-articular gas and joint effusions gradually reduce over time. In 1/23 (4.3%) patients with an open physis, gas intrusion into the physis occurred. Breakage of the bone fragment fixated by the screw was observed in 4/35 (11.4%) patients within the first 6 weeks. Screw breakage was observed in 16/35 (45.7%) patients, with a median time to first detection of 300 days. CONCLUSION: Gas bubbles in bone and soft tissue are normal findings in the context of screw resorption and should not be confused with soft-tissue infection or osteomyelitis. Gas is rarely visible in the physis. Breakage of the fixed bone fragment and/or screw can occur.

Biocompatibility and degradation comparisons of four biodegradable copolymeric osteosynthesis systems used in maxillofacial surgery: A goat model with four years follow-up.

Applying biodegradable osteosyntheses avoids the disadvantages of titanium osteosyntheses. However, foreign-body reactions remain a major concern and evidence of complete resorption is lacking. This study compared the physico-chemical properties, histological response and radiographs of four copolymeric biodegradable osteosynthesis systems in a goat model with 48-months follow-up. The systems were implanted subperiosteally in both tibia and radius of 12 Dutch White goats. The BioSorb FX [poly(70LLA-co-30DLLA)], Inion CPS [poly([70-78.5]LLA-co-[16-24]DLLA-co-4TMC)], SonicWeld Rx [poly(DLLA)], LactoSorb [poly(82LLA-co-18GA)] systems and a negative control were randomly implanted in each extremity. Samples were assessed at 6-, 12-, 18-, 24-, 36-, and 48-month follow-up. Surface topography was performed using scanning electron microscopy (SEM). Differential scanning calorimetry and gel permeation chromatography were performed on initial and explanted samples. Histological sections were systematically assessed by two blinded researchers using (polarized) light microscopy, SEM and energy-dispersive X-ray analysis. The SonicWeld Rx system was amorphous while the others were semi-crystalline. Foreign-body reactions were not observed during the complete follow-up. The SonicWeld Rx and LactoSorb systems reached bone percentages of negative controls after 18 months while the BioSorb Fx and Inion CPS systems reached these levels after 36 months. The SonicWeld Rx system showed the most predictable degradation profile. All the biodegradable systems were safe to use and well-tolerated (i.e., complete implant replacement by bone, no clinical or histological foreign body reactions, no [sterile] abscess formation, no re-interventions needed), but nanoscale residual polymeric fragments were observed at every system's assessment.

The impact of partially absorbable midurethral slings in stress urinary incontinence surgery: A cohort study.

OBJECTIVE: To evaluate the performance of retropubic midurethral slings (MUS) for the treatment of female stress urinary incontinence (SUI) at a certified continence center and to identify risk factors for sling failure. METHODS: This was a single-center cohort study including women who underwent a retropubic MUS procedure for SUI between 2012 and 2019 with a follow up of 12 months. Primary end point was cure of SUI assessed using the validated questionnaire International Consultation of Incontinence Questionnaire-Urinary Incontinence-Short Form. Univariate and multivariate analyses were applied to identify risk factors for sling failure. Wilcoxon signed-rank tests were used as paired samples tests. The significance level was set at 5%. RESULTS: A total of 662 women with a median age of 65 years (interquartile range 19 years) were included in the investigation; 523 (79.0%) presented with complicated SUI. Cure was reported by 213 (32.2%) women. Independent predictors for failure were obesity, pharmacotherapy for overactive bladder, postoperative sling adjustment, and use of partially absorbable mesh, which was correlated with a 56% decrease in the odds for achieving cure. CONCLUSION: This investigation questions the role of partially absorbable mesh for stress urinary incontinence procedures and scrutinizes the use of implants with inadequate clinical evidence.

Prognostic factors for medial open-wedge high tibial osteotomy with spacer implantation in patients with medial compartmental knee osteoarthritis.

BACKGROUND: To identify medial open-wedge high tibial osteotomy (MOWHTO) prognostic factors with wedge-shaped spacer implantation (spacer-type MOWHTO) for varus medial compartment knee osteoarthritis. METHODS: Patients who underwent spacer-type MOWHTO between August 2018 and September 2019 were prospectively enrolled in this study. Patients were divided into effective group and invalid group based on the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) score one year postoperatively. The variables assessed at baseline and one year postoperatively including age, sex, body mass index (BMI), Kellgren-Lawrence (K-L) grade, hip-knee-ankle angle (HKAA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTSA), Blackburn-Peel index (BPI), duration of symptoms, and WOMAC score were compared. Prognostic factors were analyzed using logistic regression, and the corresponding odds ratios were also calculated. RESULTS: A total of 104 patients were enrolled in the study protocol at one year postoperatively. The WOMAC score decreased from 72.39 ± 12.95 at baseline to 20.06 ± 12.96 at one year postoperatively. Univariate analysis revealed that the significant predictors of the WOMAC score were age > 70 years, BMI > 30 kg/m2, K-L grade IV, and pre-HKAA > 10° (P < 0.1 for all). Multivariable logistic regression analysis revealed that age > 70 (OR = 4.861) and K-L grade IV (OR = 6.590) were significantly associated with the higher WOMAC score at one year postoperatively. CONCLUSIONS: Spacer-type MOWHTO is an effective treatment for osteoarthritis with varus deformity. The prognostic factors for spacer-type MOWHTO are age and K-L grade.

Research progress of bioresorbable zinc alloy stent in the treatment of peripheral artery disease / 国际外科学杂志

With the development of percutaneous transluminal angioplasty, stent implantation has gradually become an important treatment for peripheral artery diseases, especially for arterial diseases of lower extremities. Due to the continuous exposure of the disadvantages of permanent metal stents and the continuous development of absorbable materials, researchers gradually pay attention to the bioresorbable stents with fewer long-term complications. At present, the application of bioresorbable stents in coronary artery disease has been relatively mature. This paper reviews the research progress of bioresorbable zinc alloy stents in peripheral artery disease.

A First-in-Man Clinical Evaluation of Sirolimus and Ascorbic Acid-Eluting Stent Systems: a Multicenter, Subject-Blinded, Randomized Study.

BACKGROUND AND OBJECTIVES: This clinical trial was conducted to evaluate the safety and efficacy of D+Storm™ drug-eluting stent (DES) and BioMatrix Flex™ DES. METHODS: This study was a multicenter, subject-single-blind, randomized, and confirmed comparative clinical trial. According to the inclusion criteria, those diagnosed with stable angina, unstable angina, silent ischemia, or non-ST-segment myocardial infarction were selected among patients with coronary artery stenosis as subjects. Among the subjects with 50% stenosis on coronary angiography, the experiment was performed on those who had a lesion with reference vessel 2.5-4.0 mm in diameter and ≤40 mm in length. The primary endpoint was an in-segment late loss and the secondary endpoints were in-stent late lumen loss, stent malapposition, the incidence of mortality, myocardial infarction, reoperation, and stent thrombosis at 36 weeks. RESULTS: 57 patients in the D+Storm™ DES group and 55 patients in the BioMatrix Flex™ DES group were enrolled in the study. Fifty-seven patients in the D+Storm™ DES group and Fifty-five patients in the BioMatrix Flex™ DES group were enrolled in the study. An average of in-segment late lumen loss was 0.08±0.13 mm in the D+Storm™ DES group and 0.14±0.32 mm in the BioMatrix Flex™ DES group with no significant difference between the 2 groups (p=0.879). In addition, there was no significant difference in adverse events between D+Storm™ DES and BioMatrix Flex™ DES. CONCLUSIONS: This study demonstrated the clinical effectiveness and safety of D+Storm™ DES implantation in patients with coronary artery disease over a 36-week follow-up period.

Improved Biocompatibility of Intra-Arterial Poly-L-Lactic Acid Stent by Tantalum Ion Implantation : 3-Month Results in a Swine Model.

OBJECTIVE: Biodegradable poly-L-lactic acid (PLLA) with a highly biocompatible surface via tantalum (Ta) ion implantation can be an innovative solution for the problems associated with current biodegradable stents. The purpose of this study is to develop a Ta-implanted PLLA stent for clinical use and to investigate its biological performance capabilities. METHODS: A series of in vitro and in vivo tests were used to assess the biological performance of bare and Ta-implanted PLLA stents. The re-endothelialization ability and thrombogenicity were examined through in vitro endothelial cell and platelet adhesion tests. An in vivo swine model was used to evaluate the effects of Ta ion implantation on subacute restenosis and thrombosis. Angiographic and histologic evaluations were conducted at one, two and three months post-treatment. RESULTS: The Ta-implanted PLLA stent was successfully fabricated, exhibiting a smooth surface morphology and modified layer integration. After Ta ion implantation, the surface properties were more favorable for rapid endothelialization and for less platelet attachment compared to the bare PLLA stent. In an in vivo animal test, follow-up angiography showed no evidence of in-stent stenosis in either group. In a microscopic histologic examination, luminal thrombus formation was significantly suppressed in the Ta-implanted PLLA stent group according to the 2-month follow-up assessment (21.2% vs. 63.9%, p=0.005). Cells positive for CD 68, a marker for the monocyte lineage, were less frequently identified around the Ta-implanted PLLA stent in the 1-month follow-up assessments. CONCLUSION: The use of a Ta-implanted PLLA stent appears to promote re-endothelialization and anti-thrombogenicity.

Immuno-regenerative biomaterials for in situ cardiovascular tissue engineering - Do patient characteristics warrant precision engineering?

In situ tissue engineering using bioresorbable material implants - or scaffolds - that harness the patient's immune response while guiding neotissue formation at the site of implantation is emerging as a novel therapy to regenerate human tissues. For the cardiovascular system, the use of such implants, like blood vessels and heart valves, is gradually entering the stage of clinical translation. This opens up the question if and to what extent patient characteristics influence tissue outcomes, necessitating the precision engineering of scaffolds to guide patient-specific neo-tissue formation. Because of the current scarcity of human in vivo data, herein we review and evaluate in vitro and preclinical investigations to predict the potential role of patient-specific parameters like sex, age, ethnicity, hemodynamics, and a multifactorial disease profile, with special emphasis on their contribution to the inflammation-driven processes of in situ tissue engineering. We conclude that patient-specific conditions have a strong impact on key aspects of in situ cardiovascular tissue engineering, including inflammation, hemodynamic conditions, scaffold resorption, and tissue remodeling capacity, suggesting that a tailored approach may be required to engineer immuno-regenerative biomaterials for safe and predictive clinical applicability.