Biomechanical analysis of the maxillary sinus floor membrane during internal sinus floor elevation with implants at different angles of the maxillary sinus angles.

OBJECTIVE: This study analyzed and compared the biomechanical properties of maxillary sinus floor mucosa with implants at three different maxillary sinus angles during a modified internal sinus floor elevation procedure. METHODS: 3D reconstruction of the implant, maxillary sinus bone, and membrane were performed. The maxillary sinus model was set at three different angles. Two internal maxillary sinus elevation models were established, and finite element analysis was used to simulate the modified maxillary sinus elevation process. The implant was elevated to 10 mm at three maxillary sinus angles when the maxillary sinus floor membrane was separated by 0 and 4 mm. The stress of the maxillary sinus floor membrane was analyzed and compared. RESULTS: When the maxillary sinus floor membrane was separated by 0 mm and elevated to 10 mm, the peak stress values of the implant on the maxillary sinus floor membrane at three different angles were as follows: maxillary sinus I: 5.14-78.32 MPa; maxillary sinus II: 2.81-73.89 MPa; and maxillary sinus III: 2.82-51.87 MPa. When the maxillary sinus floor membrane was separated by 4 mm and elevated to 10 mm, the corresponding values were as follows: maxillary sinus I: 0.50-7.25 MPa; maxillary sinus II: 0.81-16.55 MPa; and maxillary sinus III: 0.49-22.74 MPa. CONCLUSION: The risk of sinus floor membrane rupture is greatly reduced after adequate dissection of the maxillary sinus floor membrane when performing modified internal sinus elevation in a narrow maxillary sinus. In a wide maxillary sinus, the risk of rupture or perforation of the wider maxillary sinus floor is reduced, regardless of whether traditional or modified internal sinus elevation is performed at the same height.

The induced membrane technique for the management of long bone defects.

AIMS: The purpose of this study was to: review the efficacy of the induced membrane technique (IMT), also known as the Masquelet technique; and investigate the relationship between patient factors and technique variations on the outcomes of the IMT. METHODS: A systematic search was performed in CINAHL, The Cochrane Library, Embase, Ovid MEDLINE, and PubMed. We included articles from 1 January 1980 to 30 September 2019. Studies with a minimum sample size of five cases, where the IMT was performed primarily in adult patients (≥ 18 years old), in a long bone were included. Multivariate regression models were performed on patient-level data to determine variables associated with nonunion, postoperative infection, and the need for additional procedures. RESULTS: A total of 48 studies were included, with 1,386 cases treated with the IMT. Patients had a mean age of 40.7 years (4 to 88), and the mean defect size was 5.9 cm (0.5 to 26). In total, 82.3% of cases achieved union after the index second stage procedure. The mean time to union was 6.6 months (1.4 to 58.7) after the second stage. Our multivariate analysis of 450 individual patients showed that the odds of developing a nonunion were significantly increased in those with preoperative infection. Patients with tibial defects, and those with larger defects, were at significantly higher odds of developing a postoperative infection. Our analysis also demonstrated a trend towards the inclusion of antibiotics in the cement spacer having a protective effect against the need for additional procedures. CONCLUSION: The IMT is an effective management strategy for complex segmental bone defects. Standardized reporting of individual patient data or larger prospective trials is required to determine the optimal implementation of this technique. This is the most comprehensive review of the IMT, and the first to compile individual patient data and use regression models to determine predictors of outcomes. Cite this article: Bone Joint J 2020;102-B(12):1723-1734.

[Research progression and application of Laennec capsule in liver].

The Laennec capsule of liver was first discovered and reported by French doctor Rene Theophile Hyacinthe Laennec in 1802.However, it has not received enough attention for more than 200 years since then. In recent years, with the rapid development of liver surgery represented by laparoscopic technology, and the deepening of the theory of precise liver surgery, the fine anatomical structure of liver Laennec capsule has returned to the vision of liver surgeons.Recent studies have demonstrated the presence of Laennec capsule in liver histology, covering the whole liver surface, and lining the surface of liver parenchyma around the Glisson pedicle and the main hepatic vein along the inflow and outflow channels of the liver. Based on the Laennec capsule approach, it is expected to unify the current approach of Glisson pedicle and the approach of hepatic vein, and provide a new theoretical basis for the liver surgery, and guide us in the standardization of liver surgeries.

Independent Risk Factors for Postoperative Seizures in Chronic Subdural Hematoma Identified by Multiple Logistic Regression Analysis.

BACKGROUND: Postoperative seizures are potential complications of chronic subdural hematoma (cSDH). Knowledge of risk factors may help to identify patients that may benefit from antiepileptic prophylaxis. METHODS: A total of 101 patients (mean age, 70.1 ± 32.1 years) with surgical evacuation of cSDH were enrolled. We retrospectively collected patient characteristics, hematoma specifics, and procedural aspects and evaluated their impact on postoperative seizures within a 14-day follow-up period by means of bivariate logistic regression analysis. RESULTS: Postoperative seizures occurred in 14 patients (13.9%). At discharge, the mean Markwalder grading scale score was 1.1 ± 1.1 and 0.5 ± 0.8 in patients with and without seizures, respectively (P = 0.04). In the univariate analysis, preoperative midline shift (8.3 vs. 4.5 mm, P = 0.045), open craniotomy (85.7% vs. 55.2%, P = 0.031), and membranectomy (57.1% vs. 20.7%, P = 0.004) were significantly associated with postoperative seizures, respectively. In the multivariate analysis, preoperative midline shift (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.01-1.26; P = 0.029) and membranectomy (OR, 3.9; 95% CI, 1.0-15.0; P = 0.048) remained as independent risk factors for seizures. CONCLUSIONS: Perioperative antiepileptic prophylaxis may be recommended in patients with preoperative midline shift. Membranectomy may not be routinely applied during surgery.

A Novel Algorithmic Approach to Chronic Forearm Longitudinal Instability.

Essex-Lopresti Lesions are rare injuries that are often missed in the acute setting. Delayed intervention may lead to chronic wrist and elbow pain and overall poor outcomes. The literature currently supports treatments that involve shortening of the ulna to reduce the relative degree of ulnar impaction, followed by attempted reduction of the distal radioulnar joint. Although such techniques may help to temporarily reduce wrist pain secondary to ulnar impaction, they do not address the proximal migration of the radius and ipsilateral radial head dislocation at the elbow. Subsequent procedures are often needed to replace or resect the radial head. We present a novel approach to chronic Essex-Lopresti lesions resulting in anatomic restoration of forearm length with return of elbow and wrist flexion/extension as well as improved forearm pronation/supination.

Single- versus double-bundle suture button reconstruction of the forearm interosseous membrane for the chronic Essex-Lopresti lesion.

PURPOSE: Reconstruction of the ruptured interosseous membrane (IOM) is critical to restore forearm stability for the chronic Essex-Lopresti injury. Positive outcomes have been reported following IOM reconstruction with a single-bundle suture button (Mini-Tightrope) construct, although recent work suggests that double-bundle Mini-TightRope® IOM reconstruction is biomechanically superior. The purpose of this study was to determine whether double-bundle Mini-TightRope® reconstruction of the forearm IOM results in superior clinical outcomes to the single-bundle technique. METHODS: Five patients with chronic Essex-Lopresti injuries treated with double-bundle Mini-TightRope® IOM reconstruction were matched to five patients treated with single-bundle Mini-TightRope® reconstruction. Improvement in clinical examination measures and patient-reported outcomes was compared between the groups. RESULTS: Results were good to excellent in all 10 patients. At final follow-up, forearm rotation was significantly better in the single-bundle group, while maintenance of ulnar variance was better in the double-bundle group. No significant differences were noted between the two groups for any other numerical outcomes, and no complications occurred. CONCLUSION: These findings suggest that while IOM reconstruction with a double-bundle Mini-TightRope® construct results in greater resistance to proximal migration of the radius in the intermediate term, there is a modest concomitant loss of forearm rotation when compared to single-bundle reconstruction. LEVEL OF EVIDENCE: Therapeutic Level IV.

Membranectomy in Chronic Subdural Hematoma: Meta-Analysis.

OBJECTIVE: Initial management strategies of chronic subdural hematoma (cSDH) are controversial and range from bedside twist-drill or burr-hole drainage to craniotomy with membranectomy (CWM). We aim to 1) perform a meta-analysis of the available data on the outcomes of CWM for treatment of cSDH in published English-language literature and 2) evaluate collective outcomes of CWM with respect to morbidity, mortality, and recurrence rates. METHODS: A search of English-language literature performed in PubMed, Ovid, and Cochrane databases using key words ("subdural hematoma" or "chronic subdural hematoma") and ("membrane" or "membranectomy") from inception to December 2016 was conducted. Studies reporting outcomes of CWM in cSDH were included. Mortality, morbidity, follow-up duration, and recurrence rate data were extracted and analyzed. Pooled estimates and confidence intervals (CIs) were calculated for all outcomes using a random-effects model. RESULTS: Of 301 articles found, 17 articles containing 5369 patients met our eligibility criteria. Mean follow-up duration ranged from 1-30.8 months. Collective mean mortality and morbidity rates were 3.7% and 6.9%, respectively (95% CI 2-5.4% and 2.1-11.6%; P < 0.001 and P = 0.004). The collective mean recurrence rate was 7.6% (95% CI: 5%-10.2%; P < 0.001). CONCLUSIONS: Clinical data on outcomes of CWM in cSDH are limited to single institutional analyses, with considerable variation in recurrence rates and follow-up time. The rates we reported are comparable with the 5% mortality and 3%-12% morbidity rates and lower than the 10%-21% recurrence rate in the literature for burr holes or craniotomy without membranectomy. This meta-analysis provides an in-depth analysis of available data and reviews reported outcomes.

Forearm Instability: Anatomy, Biomechanics, and Treatment Options.

The forearm unit consists of the radius and ulna, a complex and interrelated set of joints (distal radioulnar joint, proximal radioulnar joint) and the soft tissue stabilizers between the 3 bones. Distally, this is represented by the triangular fibrocartilage complex at the wrist, proximally by the annular ligament at the elbow, and in the forearm by the interosseous membrane. Disruptions in any of these structures may lead to forearm instability, with consequences at each of the remaining structures.

Hyaluronic acid on collagen membranes: An experimental study in rats.

OBJECTIVE: The aim of this study was to evaluate the effect of hyaluronic acid (HA) in the structure and degradation patterns of BioGide® and OsseoGuard™ collagen membranes. HA mediates inflammation and acts in cell migration, adhesion, and differentiation, benefitting tissue remodeling and vascularization. These are desirable effects in guided regeneration procedures, but it is still unknown whether HA alters the barrier properties of absorbable membranes. DESIGN: Bone defects were created in the calvaria of rats, which were treated with HA gel 1% (HA group) or simply filled with blood clot (control group), and covered with BioGide® or OsseoGuard™. The animals were euthanized after 1, 30, and 60days, and their calvarias were processed for histological analysis. RESULTS: BioGide®, in both HA and control groups, showed vascularization, intense cell colonization, bone formation, and tissue integration at 30 and 60days. In contrast, Osseoguard™ presented minimal cellular colonization, and inflammatory reaction associated to foreign body reaction in both time points and groups. The HA group of BioGide® showed higher cell colonization (574.9±137.6) than the control group (269.1±70.83) at 60days (p<0.05). Despite this finding, the structure and degradation pattern were similar for BioGide® and Osseoguard™ in the HA and control groups. CONCLUSION: The results suggest that HA did not interfere with tissue integration and structural degradation of BioGide® and Osseoguard™ membranes.

Formação de membrana fibrótica cicatricial em paciente submetido à ceratoplastia penetrante / Fibrotic scar membrane formation in patients undergoing penetrating keratoplasty

RESUMO O surgimento de uma membrana fibrótica opacificada na córnea transplantada é pouco descrito nas literaturas nacional e mundial. O objetivo é relatar o caso de um paciente com leucoma total de olho esquerdo que foi submetido à ceratoplastia penetrante levando a formação de dupla câmara anterior devido ao surgimento de uma membrana fibrótica cicatricial. Paciente do sexo masculino, 54 anos, com leucoma total secundário a ceratite herpética, diabético há 20 anos, em uso de insulina, com retinopatia diabética não proliferativa. Realizou-se cirurgia de membranectomia com complicações pós-operatória.

ABSTRACT The emergence of opaque fibrotic membrane in transplanted cornea is little described in national and world literature. The goal is to report the case of a patient with leucoma total of left eye that was submitted to the penetrating keratoplasty leading to formation of double anterior chamber due to the emergence of a fibrotic scar membrane. Male patient, 54 years, with total herpetic keratitis secondary leucoma, diabetic for 20 years, using insulin, with non-proliferative diabetic retinopathy. Held membranectomia surgery with postoperative complications.

Interosseous membrane reconstruction with a suture-button construct for treatment of chronic forearm instability.

BACKGROUND: The purpose of this study was to report outcomes of interosseous membrane (IOM) reconstruction with a suture-button construct for treatment of chronic longitudinal forearm instability. METHODS: We performed a retrospective review with prospective follow-up of patients who underwent ulnar shortening osteotomy and IOM reconstruction with the Mini TightRope device from 2011 through 2014. Bivariate statistical analysis was used for comparison of preoperative and postoperative Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores, range of motion, grip strength, and ulnar variance. Complications and patient satisfaction were also recorded. RESULTS: Ten patients (mean age, 45.3 years) satisfied inclusion criteria: 8 treated for post-traumatic sequelae of Essex-Lopresti-type injuries, 1 for forearm instability secondary to previous elbow surgery, and 1 for instability secondary to trauma and multiple elbow surgeries. Surgeries were performed an average of 28.6 months from initial injury. At mean follow-up of 34.6 months after surgery, significant improvement was observed in elbow flexion-extension arc (+23° vs. preoperatively; P = .007), wrist flexion-extension arc (+22°; P = .016), QuickDASH score (-48; P = .000), and ulnar variance (-3.3 mm; P = .006). Three patients required additional surgery: 1 revision ulnar shortening osteotomy for persistent impingement, 1 revision ulnar osteotomy and Mini TightRope removal for lost forearm supination, and 1 fixation of a radial shaft fracture after a fall. CONCLUSION: IOM reconstruction using a suture-button construct is an effective treatment option for chronic forearm instability.

Antegrade Peroneal Flap through the Interosseous Membrane for Knee and Distal Femur Coverage.

BACKGROUND: Antegrade peroneal flaps can be rotated around the fibula to cover defects in the lower leg and lateral knee. However, these flaps cannot reliably cover the distal femur and anterior and medial knee. In the present article, the authors describe a novel technical modification that involves creating a tunnel through the interosseous membrane, through which the flap can be passed, circumventing the need to rotate around the fibula, allowing it to reach the entire knee and distal femur. METHODS: An anatomical study was performed in five cadaveric specimens to measure the gain in pedicle reaching distance when the flap is tunneled compared to transferred around the fibula. A clinical study in 12 patients was also performed to measure the gain in pedicle reaching distance and the long-term viability of the tunneled interosseous flap. RESULTS: In the anatomical study, the mean reaching distance was 7.4 ± 0.9 cm for the flaps rotated around the fibula and 17.0 ± 1.6 for the tunneled interosseous flaps (p < 0.001). In the clinical study, the mean reaching distance was 2.6 ± 1.4 cm for the flaps rotated around the fibula and 11.4 ± 2.4 for the tunneled interosseous flaps (p < 0.0000000001). Patients were followed for up to 4 years (mean, 2.5 years). All flaps survived completely, and there were no complications. CONCLUSION: By passing the antegrade peroneal flap through the interosseous membrane, instead of around the fibula, the flap reaching distance can be increased by approximately 8 cm, allowing for effective coverage of distal femur and knee defects. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Effect of Limited Tenon Capsule and Intermuscular Membranes Dissection on the Outcome of Surgery in Patients with Horizontal Strabismus.

PURPOSE: The aim of the study was to evaluate the effect of limited dissection of Tenon capsule on the outcome of strabismus surgery. METHODS: Patients between the ages of 2 and 50 years with pure horizontal strabismus were enrolled in a prospective study. Patients were divided into two groups: case and control as a non-randomized study. The method of operation was similar in both groups except for the amount of sheath Tenon dissection. In the control group the intermuscular connections and Tenon capsule were cut as much as possible. In the study group, Tenon capsule, 3-4 mm posterior to the location of the sutures over the muscle (recessed or resected), were cut and intermuscular connections remained intact. RESULTS: The study enrolled 54 patients with 27 patients in each group. In both groups, after operation, regardless of the type of surgery, the angle of strabismus was reduced (P< 0.05). For patients who had undergone bimedial recession, the angle of strabismus was corrected to 2.6 ± 0.4 prism diopters per mm (PD/mm) of muscle recession in the case group, and 2.2 ± 0.9 in the control group (P=0.2). For patients who had undergone monocular recession and resection (R&R) for esotropia, the angle of strabismus was corrected 3.4 ± 0.3 PD/mm of muscle recession or resection in the case group, and 3.2 ± 0.2 in the control group (P=0.05). For patients who had undergone bilateral recession, the angle of strabismus was corrected 2.3 ± 0.2 PD/mm of muscle recession in the case group, and 2.2 ± 0.2 in the control group (P=0.03). For patients who had undergone R&R for exotropia, the angle of strabismus was corrected 3.1 ± 0.5 PD/mm of muscle recession or resection in the case group, and 2.7 ± 0.3 in the control group (P=0.02). CONCLUSION: Connective tissue ensheathments, whether disturbed or removed, do not ultimately affect the success of the strabismus surgery.

A prospective outcome study of membranous and solid distal common canalicular obstructions.

PURPOSE: To prospectively evaluate the surgical outcomes of membranous and solid distal common canalicular obstructions (CCOs) following endoscopic dacryocystorhinostomy (EnDCR) and lacrimal intubation combined with either membranotomy or trephination. METHODS: This was a prospective, non-randomized, consecutive interventional case series. Inclusion criteria included patients undergoing EnDCR with evidence of a membranous block or more solid obstruction of the distal common canaliculus, treated with membranotomy or canalicular trephination. Complete CCO was confirmed pre-operatively using dacryocystography and dacryoscintigraphy. All patients received bicanalicular intubation for 3 months with a minimum follow-up of 12 months. Functional and anatomical success was assessed at 4 weeks, 3 months, and 12 months following surgery. Functional success was defined as subjective improvement of epiphora and anatomical success as the presence of a patent ostium and a positive dye test on nasal endoscopy. RESULTS: Twenty-nine patients were included in the study with a mean age of 58 years. Twenty-one patients (72%) received a membranotomy and eight (28%) required trephination. At 12 months, the functional and anatomical success rate in the membranotomy group was 90% (19/21) and 100% (21/21), respectively, and in trephination group the functional and anatomical success rate was 63% (5/8). There were no intra-operative or lacrimal stent-related complications. CONCLUSIONS: Identifying and excising distal CCOs in association with EnDCR and lacrimal intubation is associated with a high degree of functional (83%) and anatomical (90%) success. The success of membranous obstructions appear be superior to outcomes for solid obstructions of the distal common canaliculus that require trephination.

Epilens membrane simulating cataract in children with uveitis: a report of three cases.

Here we present the cases of three female children, of whom two were aged 6 years and one was aged 11 years. Two of the three children had bilateral uveitis and suspected cataract and Vogt-Koyanagi-Harada (VKH) disease. The third one had uveitis and suspected cataract in one eye and sympathetic ophthalmia (SO), and had undergone penetrating keratoplasty in the fellow eye following a trauma. After controlling the inflammation, we planned to perform phacoemulsification without intraocular lens implantation. However, intraoperatively, after removing the epilens membranes, the lenses appeared clear, and therefore phacoemulsification was not performed. During follow-up, the patients did not develop cataract, and visual acuity levels ranged from 20/30 to 20/100. Fundoscopy revealed VKH disease and SO. Ophthalmologists should not always assume that patients with uveitis have cataract; a transparent lens may exist behind the epilens membrane, allowing a less aggressive therapeutic approach.

Epilens membrane simulating cataract in children with uveitis: a report of three cases / Membrana epicristaliniana simulando catarata em crianças com uveíte: relato de três casos

ABSTRACTHere we present the cases of three female children, of whom two were aged 6 years and one was aged 11 years. Two of the three children had bilateral uveitis and suspected cataract and Vogt-Koyanagi-Harada (VKH) disease. The third one had uveitis and suspected cataract in one eye and sympathetic ophthalmia (SO), and had undergone penetrating keratoplasty in the fellow eye following a trauma. After controlling the inflammation, we planned to perform phacoemulsification without intraocular lens implantation. However, intraoperatively, after removing the epilens membranes, the lenses appeared clear, and therefore phacoemulsification was not performed. During follow-up, the patients did not develop cataract, and visual acuity levels ranged from 20/30 to 20/100. Fundoscopy revealed VKH disease and SO. Ophthalmologists should not always assume that patients with uveitis have cataract; a transparent lens may exist behind the epilens membrane, allowing a less aggressive therapeutic approach.

RESUMOApresentamos os casos de três meninas (duas de seis anos e uma de onze anos), com uveíte bilateral e suspeita de catarata em ambos os olhos e doença de Vogt-Koyanagi-Harada (VKH) em dois casos. No terceiro caso, oftalmia simpática e suspeita de catarata em um olho e trauma com ceratoplastia penetrante no outro olho. Após controle da inflamação, indicou-se facoemulsificação sem LIO. No per-operatório, após retirada da membrana epicristaliniana, a transparência do cristalino foi percebida, não sendo realizada a facoemulsificação. No período de acompanhamento as pacientes não desenvolveram catarata e a acuidade visual variou de 20/30 a 20/100. O exame de fundoscopia reforçou o diagnóstico de VKH e oftalmia simpática. Portanto, é muito importante que o oftalmologista esteja sempre atento quando se deparar com um caso de uveíte com suspeita de catarata, porque, por trás da membrana epicristaliniana pode existir um cristalino transparente, o que leva a uma conduta terapêutica menos agressiva.