Palladium nanoballs coupled with smartphone-thermal reader for photothermal lateral flow immunoassay of Aß 1-40.

Amyloid beta 1-40 (Aß 1-40) is one of the most abundant substances in the body with the capacity to form insoluble aggregates and is a universal biomarker for the prediction of Alzheimer's disease. Here, a palladium nanoball (PNB)-strip was developed and coupled with a smartphone-thermal reader as an ultrasensitive and cost-effective platform for Aß 1-40 detection. In this study, PNB was synthesized and introduced into lateral flow strips as an alternative signal source to gold nanoparticles to improve sensitivity because the PNB has a better heat generation ability. Quantitative analysis was performed using a self-developed smartphone-thermal reader, which is portable and cost-effective. The detection limit of the system was determined to be 20 pg mL-1, which fulfils the need for clinical diagnosis at the point-of-care. This work highlights a PNB-strip coupled smartphone-thermal reader for ultrasensitive and cost-effective Aß 1-40 detection.

Displaced posterior pelvic ring fractures treated with an unlocking closed reduction technique: Prognostic factors associated with closed reduction failure, reduction quality, and fixation failure.

PURPOSES: This study aimed to evaluate the clinical effect of the unlocking closed reduction technique (UCRT) for the displaced posterior pelvic ring fractures and to analyze the factors associated with failure of closed reduction and fixation. PATIENTS AND METHODS: Data from patients admitted with displaced posterior pelvic ring fractures initially treated with the URCT from July 2017 to January 2020 were extracted. Clinical and radiological factors including fracture classification, interval days from injury to surgery, number of screws, and type of fixation for the posterior pelvic ring were analyzed to evaluate their correlation with closed reduction failure, reduction quality, and fixation failure. Then a logistic regression model was used for statistical analysis to eliminate confusion factors. RESULTS: Ninety-seven patients with displaced posterior pelvic ring fractures were followed for a mean of 1.7 years after surgery. Successful closed reduction and percutaneous fixation were achieved for 89 patients (91.8%), of which 82 patients (92.1%) achieved an excellent or good reduction. Closed reduction failure which converted to open reduction was recorded for eight patients (8.2%). AO/OTA type C3 fracture (p = 0.036) and osteoporosis (p = 0.012) were significant factors for closed reduction failure. Excellent was recorded for 76 patients (78.4%) and acute (1-21 days) interval days from injury to surgery was an associated factor for reduction quality. For AO/OTA type C1 fractures, no more than two short screws (unilateral iliosacral screws) or a single long screw (transiliac-transsacral screws) were independent prognostic factors of fixation failure (p = 0.026). CONCLUSIONS: Displaced posterior pelvic ring fractures treated with the UCRT are associated with excellent/ good radiological results. However, in patients with AO/OTA type C3 pelvic fracture and osteoporosis, the backup plan of open reduction should be routinely prepared. The patient should be brought to the operating room within three weeks to get a good reduction result. Two long screws or one long screw combined with two short screws are required to create a strong construct for AO/OTA type C1 pelvic fractures.

Lumbopelvic fixation with S2 alar-iliac screws for U-shaped sacral fractures.

OBJECTIVE: To investigate the surgical methods and clinical effects of lumbopelvic fixation (LPF) with S2 alar-iliac (S2AI) screws for U-shaped sacral fractures. METHODS: From December 2019 to August 2020, 14 patients with U-shaped sacral fractures were treated with LPF using S2AI screws. Demographics, fracture classification, mechanism of injury, surgical treatment, complications and clinical results were assessed. All patients had a LPF with or without nerve decompression. The reduction quality was evaluated according to the Matta criteria. Neurological function was evaluated according to the Gibbons grading. The activities of daily life were evaluated according to the Majeed scoring system at the last follow-up. RESULTS: Among 14 consecutive patients with U-shaped sacral fractures, the age at injury ranged from 13 to 72 years (average 30.3 ± 17.5 years). There were 4 males and 10 females. All patients were followed up for 6-15 months (average 7.8 ± 2.7 months). Thirteen patients were fixed with bilateral S2AI screws, and one patient was fixed only unilaterally due to unilateral spinopelvic dissociation. The excellent and good rate of postoperative pelvic reduction quality was 92% (excellent 10, good 3, fair 1). At the latest follow-up, the excellent and good rate of pelvic function was 100% (excellent 9, good 5) and all patients achieved different extents of neurological recovery. One patient had a postoperative superficial surgical site infection, which healed after debridement. Radiological examination at 3-6 months after operation showed that all fractures had healed. No complications were found in any patients during follow-up, such as implant fracture, loss of reduction, deep wound infection, wound dehiscence and screw protrusion discomfort. CONCLUSION: LPF with S2AI screws for the treatment of U-shaped sacral fractures has exhibited distinct advantages, including firm fixation, a low rate of surgical site complications and satisfactory clinical efficacy. This approach provides sufficient stability to accelerate the commencement of postoperative rehabilitation.

Sacral osteotomy combined with triangular osteosynthesis in the treatment of malunion and nonunion of vertically displaced pelvic fractures.

BACKGROUND: Malunion and nonunion of vertically displaced pelvic fractures result in lower limb length discrepancies, claudication, and pain. There have been few previous reports of this type of corrective surgery for these old pelvic fractures. We present a surgical technique of sacral osteotomy combined with triangular osteosynthesis in the treatment of malunion and nonunion of vertically displaced pelvic fractures and report on its short-term clinical results. METHODS: We retrospectively reviewed nine patients (five males and four females) with malunion or nonunion of vertically displaced pelvic fractures treated with sacral osteotomy and triangular osteosynthesis from April 2015 to January 2020. The age ranged from 14 to 45 years (average, 30.7 years). The time from injury to deformity correction surgery ranged from 3 months to 5 years (average, 12.8 months). The vertical displacement of a unilateral hemipelvis was 3.0-4.5 cm (average, 3.80 cm). According to AO/OTA classification at the initial fracture, there are eight cases in type C1.3 and one case in type C3.3. Sacral osteotomy and triangular osteosynthesis were used in all nine patients. The degree of unilateral hemipelvic reduction was assessed postoperatively based on measurements from the anteroposterior (AP) X-ray. Majeed score and pain visual analog scale (VAS) were used to assess the therapeutic effect of the patients during follow-up. RESULTS: In all nine patients, postoperative AP X-ray showed correction displacement of 1.7-3.9 cm (average, 3.20 cm). All the patients were followed up for 6-36 months (average, 12.7 months). At the last follow-up, the Majeed score of pelvic fracture increased from an average of 53.9 points (30-84 points) preoperatively to 87.0 points (72-94 points), and the VAS score for pain decreased from an average of 6.0 points (4-8 points) preoperatively to 1.2 points (0-3 points). None had complications like infection, implant broken, screw loosening, iatrogenic nerve, and blood vessel injury. CONCLUSION: Sacral osteotomy combined with triangular osteosynthesis for the treatment of pelvic malunion and nonunion caused by sacral fractures can correct significantly vertical displacement of a unilateral pelvis, prolong limb length, and reconstruct the stability of a pelvic ring, achieving good clinical results.

S2-Alar-Iliac Screw Fixation versus Iliac Screw Fixation in the Treatment of Sacral Fractures.

PURPOSE: To compare the short-term therapeutic effects of S2-alar-iliac (S2AI) screw fixation and iliac screw fixation techniques in managing sacral fractures. METHODS: From September 2015 to May 2020, 42 patients with sacral fractures who underwent lumbopelvic fixation by a single surgeon were analyzed. The patients were divided into the S2AI screw group (19 patients) and the iliac screw group (23 patients). Operative data, reduction quality, postoperative complications, and functional outcomes were evaluated. RESULTS: The incidence of unplanned reoperation was significantly different between patients treated with S2AI screws than in those treated with iliac screws (0 versus 6, p = 0.02). The mean intraoperative estimated blood loss was 405.26 ± 229.67 mL in the S2AI screw group and 539.13 ± 246.32 mL in the iliac screw group (P = 0.08). No significant difference was observed in either group regarding the quality of reduction, functional outcome, or low back pain. The reduction quality based on the Matta criteria and excellent/good outcomes were 21/2 in the iliac screw group and 17/2 in the S2AI screw group. The functional outcomes based on the Majeed score and excellent/good/fair outcomes were 17/3/3 in the iliac screw group and 17/1/1 in the S2AI screw group. No complications, including implant breakage, loosening of the implant, or loss of reduction were found in either group during follow-up. CONCLUSION: Both S2AI screws and iliac screws were effective in the treatment of sacral fractures. The use of S2AI screws, however, was independently associated with fewer unplanned reoperations for surgical site infection, wound dehiscence, and symptoms of screw protrusion than the use of iliac screws.