A case of endogenous endophthalmitis caused by Escherichia coli septicemia.

Endogenous endophthalmitis is a severe sight-threatening condition that requires urgent intervention. It is a rare complication of Escherichia coli septicemia. We herein report a case of left eye endogenous endophthalmitis with uncontrolled type 2 diabetes mellitus with pyelonephritis associated with Escherichia coli septicemia. Vitrectomy was done along with intravitreal antibiotics and steroids. There was significant improvement in vision after vitrectomy.

Extensive Metallosis in a Primary Knee Arthroplasty as a Result of Polyethylene Wear: Is It Avoidable?

Metallosis is known to occur in metal-on-metal arthroplasty and has been of concern to orthopaedic surgeons worldwide. It is a rare, late complication of total knee arthroplasty (TKA), in which metal-on-metal contact leads to metal debris deposition in the surrounding tissue. Reasons for metal-on-metal contact could range from wear of the polyethylene insert to abnormal joint biomechanics. Many components can affect the development of metallosis, with polyethylene wear being the most common cause of metallosis. This paper discusses the case of an 85-year-old man who developed metallosis, attributed to polyethylene wear, 24 years after undergoing TKA. It also highlights the different components of knee prostheses, evaluates the efficacy of different types of polyethylene, and explores whether ceramic coating can improve TKA outcomes and reduce complications such as metallosis.

Impact of surgical timing and type of operative procedure on outcomes in periprosthetic hip fractures: an observational study at an NHS trust centre in the UK.

PURPOSE: There is a global trend of increased periprosthetic fractures due to the growing number of arthroplasty procedures. The present study assessed the impact of factors such as time to surgery and type of surgery on the outcomes, which have been seldom evaluated for periprosthetic fractures. METHODS: An observational study was conducted on consecutive 87 patients within an NHS district hospital trust in the UK. Patients who underwent a complete hip replacement prior to the fracture, received fixation therapy, or underwent revision surgery within the specified time were screened. Patients were grouped in two ways: based on time to surgery and based on surgery type. Logistic regression models were performed to assess for statistically significant differences in post-operative complication, 30-day, and 1-year mortality rates between groups, whilst adjusting for age, gender, and ASA grade. RESULTS: Forty-one patients underwent open reduction and internal fixation (ORIF), 29 patients underwent revision arthroplasty, and 17 patients were subjected to both, ORIF and revision arthroplasty. Sixty of the 87 patients were operated on > 48 h of injury. The median hospital stay was significantly lower in the ORIF plus revision arthroplasty group, versus other surgical groups (p < 0.05) whilst it was significantly higher in the group of patients who underwent surgery after 48 h of injury (p < 0.05). Numerically higher mortality was noted in the revision arthroplasty group (31.03%, p > 0.05). The group that was operated after 48 h of injury showed greater mortality but was comparable to the other group (25% vs. 14.81%, p > 0.05). For post-operative complications, none of the variables were significantly predictive (p > 0.05). However, for 30-day mortality, ASA grade (p = 0.04) and intra-operative complications (p = 0.0001) were significantly predictive. Additionally, for 1-year mortality, ASA grade (p = 0.004) was noted to be significantly predictive. CONCLUSION: Revision and delayed periprosthetic fracture management (> 48 h after injury) group showed a numerically greater mortality risk; however, this finding was not statistically significant. ASA grading at baseline is predictive of mortality for periprosthetic fractures.

Use of a Trephine to Extract a Fractured Corail Femoral Stem During Revision Total Hip Arthroplasty: Tips From Our Case Report.

Despite the significant advancements in the field of total hip arthroplasty (THA) and prosthesis designs, fracture of the modular femoral stem after THA can occur rarely and needs attention. Orthopaedic surgeons face a daunting task when it comes to the removal of a broken stem. The use of a trephine reamer has been evaluated for extracting the distal femoral stem, and this case report tries to address some key tips for the same. A 67-year-old obese male, without any major medical comorbidities, presented to the Royal Lancaster Infirmary orthopaedic outpatient department with a complaint of acute-on-chronic right anterior thigh pain that worsened over a few weeks. He had a history of bilateral staged uncemented THA done around 12 years ago. The plain radiological images confirmed the presence of a fracture of the Corail femoral stem. A posterior approach was used to dislocate the hip and the distal broken part of the stem was removed using trephines. Reamers were used and care was taken to prevent thermal necrosis by using intermittent saline lavage. After the removal of the fractured femoral stem, a cemented femoral revision THA was performed, which was uneventful. The patient walked without any aid or thigh pain postoperatively during his last follow-up. Using trephines to remove broken femoral stems is an effective and safe method. Intraoperative measures can help in avoiding heat necrosis while using a trephine reamer for extracting the fractured femoral stem. Regular follow-up and counselling are important after THA, to avoid a delayed diagnosis of non-traumatic femoral stem fractures.

Fluid interfaces laden by force dipoles: towards active matter-driven microfluidic flows.

In recent years, nonlinear microfluidics in combination with lab-on-a-chip devices has opened a new avenue for chemical and biomedical applications such as droplet formation and cell sorting. In this article, we integrate ideas from active matter into a microfluidic setting, where two fluid layers with identical densities but different viscosities flow through a microfluidic channel. Most importantly, the fluid interface is laden with active particles that act with dipolar forces on the adjacent fluids and thereby generate flows. We perform lattice-Boltzmann simulations and combine them with phase field dynamics of the interface and an advection-diffusion equation for the density of active particles. We show that only contractile force dipoles can destabilize the flat fluid interface. It develops a viscous finger from which droplets break up. For interfaces with non-zero surface tension, a critical value of activity equal to the surface tension is necessary to trigger the instability. Since activity depends on the density of force dipoles, the interface can develop steady deformation. Lastly, we demonstrate how to control droplet formation using switchable activity.

Non-Union And Resorption Of Extended Trochanteric Osteotomy And Management Using Modular Tapered Stem In Patient With Extensive Surgical History.

Extended trochanteric osteotomy is an invaluable technique for enhancing femoral exposure during revision total hip arthroplasty. Complications are rarely reported but may include non-union. Even rarer is the incidence of extended trochanteric osteotomy resorption. We present our experience using a modular tapered stem in managing a resorbed extended trochanteric osteotomy following revision total hip arthroplasty in a patient with extensive hip surgical history. Good surgical technique is important in the prevention and management of resorption. It is also important to identify high risk patients such as smokers or those with peripheral vascular disease. Long femoral stem prosthesis with diaphyseal fixation may help in dealing with proximal bone loss due to resorption of an extended trochanteric osteotomy, and avoids the need for allogenic bone graft.

Fracture Of An Exeter™ V40™ Stem Through The Insertion Guide Hole And Revision Using Cement-In-Cement Technique.

Fracture of the Exeter™ V40™ stem is uncommonly reported in the literature. The cement-in-cement femoral revision is a described technique for revising well-cemented femoral components during revision hip arthroplasty. We present our experience using this technique in managing a fractured Exeter™ V40™ stem. There have been 24 reported Exeter™ V40™ stem fractures: 12 at the body and 12 at the neck. 3 of the reported fracture at the neck cases have occurred at the superior aspect of the neck-shaft junction which is an unusual site for failure of this stem. Our patient's fracture pattern matches this unusual presentation. This report has added to the limited evidence indicating the area around the insertion guide hole as a potential site through which stem fracture may begin and propagate inferiorly. The cement-in-cement technique may be successfully employed in managing Exeter™ V40™ stem fractures, without need for extended trochanteric osteotomy or cortical window.

Instability of a liquid sheet with viscosity contrast in inertial microfluidics.

Flows at moderate Reynolds numbers in inertial microfluidics enable high throughput and inertial focusing of particles and cells with relevance in biomedical applications. In the present work, we consider a viscosity-stratified three-layer flow in the inertial regime. We investigate the interfacial instability of a liquid sheet surrounded by a density-matched but more viscous fluid in a channel flow. We use linear stability analysis based on the Orr-Sommerfeld equation and direct numerical simulations with the lattice Boltzmann method (LBM) to perform an extensive parameter study. Our aim is to contribute to a controlled droplet production in inertial microfluidics. In the first part, on the linear stability analysis we show that the growth rate of the fastest growing mode [Formula: see text] increases with the Reynolds number [Formula: see text] and that its wavelength [Formula: see text] is always smaller than the channel width w for sufficiently small interfacial tension [Formula: see text]. For thin sheets we find the scaling relation [Formula: see text], where m is viscosity ratio and [Formula: see text] the sheet thickness. In contrast, for thicker sheets [Formula: see text] decreases with increasing [Formula: see text] or m due to the nearby channel walls. Examining the eigenvalue spectra, we identify Yih modes at the interface. In the second part on the LBM simulations, the thin liquid sheet develops two distinct dynamic states: waves traveling along the interface and breakup into droplets with bullet shape. For smaller flow rates and larger sheet thicknesses, we also observe ligament formation and the sheet eventually evolves irregularly. Our work gives some indication how droplet formation can be controlled with a suitable parameter set [Formula: see text].

Medium term outcome of Lancaster cortical window technique for extraction of femoral stem in revision hip arthroplasty.

BACKGROUND: The extraction of a femoral stem during the revision hip arthroplasty can be a daunting task and can lead to catastrophic complications for the patient. A sound technique employed intraoperatively helps in the speedy recovery of the patient and reduces the risk of future surgical interventions. In this study, we present a medium-term outcome of our novel Lancaster cortical window technique which can be used for the removal of cemented or uncemented femoral stems. METHODS: The study was conducted at a specialist centre in the north-west of the UK from January 2014 to May 2019. This is a retrospective case series where patients were treated surgically using the Lancaster cortical window technique for removal of the femoral implant during a revision hip arthroplasty. Patient's electronic notes and radiographs were used to evaluate the functional and radiological outcome. RESULTS: In this study, 18 patients were managed surgically using the novel Lancaster window technique. The mean age of all the patients was 81.5 years, and the male to female ratio was 10:8. Fifteen patients underwent revision surgery for aseptic loosening of the femoral and acetabular components. The rest of the three patients had revision surgery for a broken femoral stem, intraoperative femoral canal perforation while implanting a total hip replacement femoral stem and infection. Twelve femurs were replanted with uncemented long femoral stems and six with long cemented stems. The cortical window osteotomy united in all the patients in 4.2 months (mean). The mean follow-up of these patients is 20.9 months, and none of them had any implant subsidence or loosening at the time of their last follow-up. CONCLUSION: We believe Lancaster cortical window technique can be safely used for the removal of cemented stems during revision hip arthroplasty without the need for expensive equipment.

A pair of particles in inertial microfluidics: effect of shape, softness, and position.

Lab-on-a-chip devices based on inertial microfluidics have emerged as a promising technique to manipulate particles in a precise way. Inertial microfluidics exploits internal hydrodynamic forces and the mechanical structure of particles to achieve separation and focusing. The article focuses on the hydrodynamic interaction of two particles. This will help to develop an understanding of the dynamics of particle trains in inertial microfluidics, which are typical structures in multi-particle systems. We perform three-dimensional lattice Boltzmann simulations combined with the immersed boundary method to unravel the dynamics of various mono- and bi-dispersed pairs in inertial microfluidics. We study the influence of different starting positions for mono- and bi-dispersed pairs. We also change their deformability from relatively soft to rigid and choose spherical and biconcave particle shapes. The observed two-particle motions in the present work can be categorized into four types: stable pair, stable pair with damped oscillations, stable pair with bounded oscillations, and unstable pair. We show that stable pairs become unstable when increasing the particle stiffness. Furthermore, a pair with both capsules in the same channel half is more prone to become unstable than a pair with capsules in opposite channel halves.

Early catastrophic failure of a PINNACLE MARATHON® polyethylene acetabular liner: a report of a malpositioned PINNACLE DUOFIX HA® acetabular shell resulting in point loading and accelerated wear.

BACKGROUND: Highly cross-linked polyethylene in total hip arthroplasty (THA) has been shown to decrease wear rate compared with a conventional polyethylene liner. However, it has also been reported that the manufacturing processes can cause early failure of the implant. CASE: We describe early catastrophic failure at <4 years following primary THA surgery of a PINNACLE MARATHON® polyethylene acetabular liner resulting from a malaligned PINNACLE DUOFIX HA® acetabular shell with resultant point loading. Radiographs revealed a malaligned acetabular shell and superior subluxation of the femoral head out of the liner. At revision surgery operative findings revealed that the acetabular shell alignment was in of 50° of anteversion and 70° of inclination. Significant metallosis in the surrounding tissues was observed. CONCLUSIONS: We conclude that a malpositioned acetabular shell resulting in point loading and abnormal contact stresses was the mechanism of failure. Our case highlights the importance of achieving correct acetabular component alignment in total hip arthroplasty.

Patella in total knee arthroplasty: to resurface or not to--a cohort study of staged bilateral total knee arthroplasty.

The aim of this study was to assess medium term results of patellar resurfacing in total knee arthroplasty, specifically looking at anterior knee pain, patellofemoral function and need for reoperation. A prospective cohort study was conducted with patients undergoing staged bilateral knee arthroplasty with the patella being resurfaced only on one side. This was due to change in the clinical practice of the senior author. Sixty patients were reviewed clinically and radiologically on a regular basis. The surgery was either performed or supervised by the senior author in all cases. All patients received the cemented press-fit condylar© prosthesis. The Knee Society clinical rating system was used. Scores were recorded pre-operatively and post-operatively at three months, one year, two years and three yearly thereafter. The mean age of patients in the study group was 75 years (range: 62-89 years). There were 42 women and 18 men in the study. The mean duration of follow-up was 4.5 years (range: 2-12 years). There was no significant difference in the pre-operative scores in both groups. There were significantly better scores (p < 0.05) on the resurfaced side as compared to the non-resurfaced side at final follow-up. No revision was carried out for patellofemoral complications on the resurfaced side. Four patients required revision in the form of patellar resurfacing on the non-resurfaced side for persistent anterior knee pain. Patellar resurfacing is recommended in total knee arthroplasty for better functional outcome with regards to anterior knee pain and patellofemoral function.

The efficacy of combined popliteal and ankle blocks in forefoot surgery.

BACKGROUND: Postoperative pain following forefoot surgery can be difficult to control with oral analgesia. The aim of this study was to compare the efficacy of a combined popliteal and ankle block with that of an ankle block alone in providing postoperative analgesia following forefoot surgery. METHODS: We performed a prospective, randomized, controlled single-blind study involving sixty-three patients, twenty-six of whom had a combined ankle and popliteal block and thirty-seven of whom had an ankle block alone. All patients underwent an elective osseous surgical procedure on the forefoot. Postoperative pain was evaluated with use of a visual analogue scale and a verbal response form. Patient satisfaction was also recorded. RESULTS: The patients who had had a combined popliteal and ankle block had significantly less pain at six hours postoperatively (p = 0.011), twenty-four hours postoperatively (p < 0.001), and at discharge (p = 0.014). This group of patients also had higher satisfaction with pain relief. CONCLUSIONS: A popliteal block in conjunction with an ankle block provides significantly better pain relief than does an ankle block alone in patients undergoing forefoot surgery.

Bilateral radial head fractures in a woman with trivial trauma.

Radial head fractures are common injuries, occurring in about 20% of all acute elbow injuries. Isolated radial head fractures are not common and include about 2% of all fractures around the elbow. Bilateral radial head fractures are rare and usually associated with severe trauma and associated fractures and dislocations. We report a case of bilateral undisplaced radial head fracture in a woman, following a simple fall. Early recognition, proper management, and physical therapy led to complete recovery and full functional movement of the elbow.

A midface swelling in a child - A possible diagnostic dilemma.

A lump on the midface of a child can pose as a diagnostic dilemma. There is a wide variety of possible differential diagnoses, ranging from simple benign conditions such as a sebaceous cyst, dermoid cyst, lipoma, neuroma and neurofibroma, to potentially devastating conditions such as odontogenic myxoma. A case of a child in which the formulation of a definite diagnosis was clinically and histologically challenging is presented.

Une bosse du plan sagittal chez un enfant peut constituer un dilemme diagnostique. Il existe toute une série de diagnostics différentiels possibles, en passant par de simples troubles bénins comme un kyste sébacé, un kyste dermoïde, un lipome, un névrome ou un neurofibrome jusqu'à des pathologies au potentiel dévastateur, comme un myxome odontogène. Le cas d'un enfant pour qui la formulation d'un diagnostic définitif constituait un défi clinique et histologique est présenté.