Cause Of Postoperative Failure Research Articles

Patient-specific instrument for unicompartmental knee arthroplasty does not reduce the outliers in alignment or improve postoperative function: a meta-analysis and systematic review.

Unsatisfactory alignment in unicompartmental knee arthroplasty (UKA) is one potential cause of postoperative failure. Patient-specific instruments (PSIs) are designed to improve the alignment of the prostheses, but the effect of PSIs on the alignment or clinical outcome is controversial and lacks validated evidence. We conducted a meta-analysis and systematic review to determine the effect of PSIs on UKA outcomes for the first time. A systematic literature search in MEDLINE, EMBASE, CNKI (Chinese database) and Cochrane Central Register of Controlled Trials (up to June 2019) was performed to collect studies that compared PSIs with conventional instruments. Two reviewers independently screened all the records on the basis of inclusion and exclusion criteria. Quality assessments with Cochrane's quality assessment tool or Newcastle-Ottawa scale (NOS) were conducted, the data were extracted, and statistical analyses were completed. Ten studies with 444 knees were included. The meta-analysis confirmed that PSIs contributed to reduced errors in the alignment of the femoral compartment in the sagittal plane (mean difference = -2.53, CI [-3.14, -1.99], P < 0.01) and the tibial compartment in both the coronal (mean difference = -0.97, CI [-1.44, -0.49], P < 0.01) and the sagittal plane (mean difference = -1.29, CI [-1.81, -0.76], P < 0.01). One study supported that PSIs reduced outliers in inexperienced surgeons; however, all studies investigating PSIs among experienced surgeons suggested that PSIs cannot reduce the percentage of outliers. There was no significant difference in the postoperative score (mean difference = -0.06, CI [-0.36, 0.23], P = 0.68) or rate of complications (RR = 1.02, CI [0.15, 6.79], P = 0.99) between PSIs and conventional instruments. The findings of this study suggest PSIs could not reduce the percentage of outliers in UKA patients for experts, and postoperative scores and complication rates are not improved by PSIs, compared with conventional instruments. Based on this meta-analysis and systematic review, no practical benefit to UKAs in experts was detected in PSIs. The findings of this study also suggest that PSIs improved alignment of UKA and might be beneficial to inexperienced surgeons, but it is still unclear whether this improvement is clinically significant and the evidence of inexperienced surgeons is limited. Therefore, more high-quality RCTs are need to be carried out in the future.

MEK inhibition prevents TGF‑β1‑induced myofibroblast transdifferentiation in human tenon fibroblasts.

Subconjunctival fibrosis represents the primary cause of postoperative failure of trabeculectomy, and at present there is a lack of effective intervention strategies. The present study aimed to investigate the effect of the mitogen-activated protein kinase kinase (MEK) inhibitor U0126 on human tenon fibroblast (HTF) myofibrosis transdifferentiation, and to illuminate the underlying molecular mechanisms involved. It was demonstrated that U0126 significantly inhibited the proliferation, migration and collagen contraction of HTFs stimulated with TGF-β1. In addition, U0126 largely attenuated the TGF-β1-induced conversion of HTFs into myofibroblasts, as indicated by a downregulation of the mRNA and protein expression of α-smooth muscle actin and zinc finger protein SNAI1, and by ameliorating the 3D-collagen contraction response. Mechanistically, U0126 suppressed the TGF-β1-stimulated phosphorylation of mothers against decapentaplegic homolog 2/3, P38 mitogen-activated protein kinase and extracellular signal-regulated kinase 1/2, indicating that U0126 may inhibit HTF activation through the canonical and non-canonical signaling pathways of TGF-β1. Therefore, U0126 exhibits a potent anti-fibrotic effect among HTFs, and the inhibition of MEK signaling may serve as an alternative intervention strategy for the treatment of trabeculectomy-associated fibrosis.

Reason and treatment of failure of proximal femoral nail antirotation internal fixation for femoral intertrochanteric fractures of senile patients.

The cause of postoperative failure after the treatment of femoral intertrochanteric fracture with proximal femoral nail antirotation (PFNA) was analyzed, and the reoperative methods were examined. Nine failures of 308 femoral intertrochanteric fracture patients with PFNA were treated with femoral prosthesis total hip replacement (THR) and reoperative internal fixation. All nine patients were analyzed to determine the cause of failure. The causes of failed internal fixation in the intertrochanteric-fractured patients included perforation of the helical blade into the hip joint in three cases, cutting-out of the helical blade exit outside in two cases, and hip varus as a result of cutting-out the helical blade in two cases. Seven patients with failed internal fixation were treated with THR. Two patients who had femoral shaft fractures at the end of the nail were treated with longer PFNA. Faulty operative procedures, unsatisfactory reductions, serious osteoporosis, and incorrect positioning of the helical blade were the most important factors responsible for the failed internal fixation. Satisfactory results were achieved with THR and refixation relative to the causes of the failed internal fixation.

UP-01.080 Comparing Results of Two Types of Transobturator Tape (TOT), In-Out Technique, Used in Women with Stress Urinary Incontinence

To appreciate retrospectively the efficacy of the two types of transobturator tape (IVS and Swing-Band) in the treatment of stress urinary incontinence in women and the analysis of the causes of postoperative failure.

Use of computational fluid dynamics in the design of surgical procedures: Application to the study of competitive flows in cavopulmonary connections

Computational fluid dynamic methods based on a finite-element technique were applied to the study of (1) competition of flows in the inferior and superior venae cavae in total cavopulmonary connection, and (2) competition between flow in the superior vena cava and forward flow from a stenosed pulmonary artery in bidirectional cavopulmonary anastomosis. Models corresponding to various degrees of offsetting and shape of the inferior vena caval anastomosis were simulated to evaluate energy dissipation and flow distribution between the two lungs. A minimal energy loss with optimal flow distribution between the two lungs was obtained by enlarging the inferior vena caval anastomosis toward the right pulmonary artery. This modified technique of total cavopulmonary connection is described. A computational model of the operation was developed in an attempt to understand the mechanisms of postoperative failure. In tight pulmonary artery stenosis (75%), the pulsatile forward flow is primarily directed to the left pulmonary artery, with little influence on superior vena caval pressure and the right pulmonary artery. Pulsatile forward flows corresponding to 15%, 30%, 45%, and 60% of the systemic artery output increased the mean pulmonary artery and superior vena caval pressures by 1, 1.7, 2.4, and 3.6 mm Hg, respectively. Although the modeling studies were not able to determine the cause of postoperative failure, they emphasize the impact of local geometry on flow dynamics. More simulations are required for further investigation of the problem. (J T HORAC C ARDIOVASC S URG 1996;111:502-13)

Clinical and Research Aspects of Subtotal Open-Sky Vitrectomy: XXXVII Edward Jackson Memorial Lecture

Subtotal open-sky vitrectomy can be used to improve visual function in some eyes for which closed vitrectomy is useless. Open-sky vitrectomy allows easier access for surgical instruments, especially to anterior fundus structures. The technique also improves the visibility of intraocular structures. The surgical procedure, which uses special instruments and high-molecular-weight hyaluronic acid, is divided into four stages: preparation, operating inside the vitreous cavity, wound closure, and retinal reattachment. In 290 consecutive operations for which complete follow-up data are available, retinal reattachment was achieved in 61 eyes (21%). The greatest number of successes (16 of 30 cases [53%]) was achieved in severe tractional retinal detachments. Such results are encouraging because these eyes were considered inoperable by other techniques. Open-sky vitreous surgery is performed through a corneal incision, but a scleral incision over the pars plana may become the method of choice in selected cases. The development of a preretinal fibrin membrane, as a result of either a closed vitrectomy or an open-sky procedure, may be a major cause of postoperative failure. Hypotony during surgery is probably the main precipitating factor of intraocular fibrin membrane formation.