Using artificial neural networks to predict impingement and dislocation in total hip arthroplasty.

Dislocation after total hip arthroplasty (THA) remains a major issue and an important post-surgical complication. Impingement and subsequent dislocation are influenced by the design (head size) and position (anteversion and abduction angles) of the acetabulum and different movements of the patient, with external extension and internal flexion the most critical movements. The aim of this study is to develop a computational tool based on a three-dimensional (3D) parametric finite element (FE) model and an artificial neural network (ANN) to assist clinicians in identifying the optimal prosthesis design and position of the acetabular cup to reduce the probability of impingement and dislocation. A 3D parametric model of a THA was used. The model parameters were the femoral head size and the acetabulum abduction and anteversion angles. Simulations run with this parametric model were used to train an ANN, which predicts the range of movement (ROM) before impingement and dislocation. This study recreates different configurations and obtains absolute errors lower than 5.5° between the ROM obtained from the FE simulations and the ANN predictions. The ROM is also predicted for patients who had already suffered dislocation after THA, and the computational predictions confirm the patient's dislocations. Summarising, the combination of a 3D parametric FE model of a THA and an ANN is a useful computational tool to predict the ROM allowed for different designs of prosthesis heads.

Do we perform surgical programming well? How can we improve it? / ¿Realizamos bien la programación quirúrgica? ¿Cómo podemos mejorarla?

The objective is to establish the duration of our interventions, intermediate times and surgical performance. This will create a virtual waiting list to apply a mathematical programme that performs programming with maximum performance. MATERIAL AND METHODS: Retrospective review of 49 surgical sessions obtaining the delay in start time, intermediate time and surgical performance. Retrospective review of 4,045 interventions performed in the last 3 years to obtain the average duration of each type of surgery. Creation of a virtual waiting list of 700 patients in order to perform virtual programming through the MIQCP-P until achieving optimal performance. RESULTS: Our surgical performance with manual programming was 75.9%, ending 22.4% later than 3pm. The performance in the days without suspensions was 78.4%. The delay at start time was 9.7min. The optimum performance was 77.5% with a confidence of finishing before 15h of 80.6%. The waiting list has been scheduled in 254 sessions. DISCUSSION: Our manual surgical performance without suspensions (78.4%) was superior to the optimal (77.5%), generating days finished later than 3pm and suspensions. The possibilities for improvement are to achieve punctuality at the start time and adjust the schedule to the ideal performance. The virtual programming has allowed us to obtain our ideal performance and to establish the number of operating rooms necessary to solve the waiting list created. CONCLUSIONS: The data obtained in virtual mathematical programming are reliable enough to implement this model with guarantees.

Successful use of lipid emulsion to resuscitate a foal after intravenous lidocaine induced cardiovascular collapse.

BACKGROUND: Lipid emulsion has been reported to be effective for the treatment of local anaesthetic overdoses in rats, dogs and man. OBJECTIVES: To describe the successful treatment of cardiovascular lidocaine toxicity in a foal with intravenous lipid administration. STUDY DESIGN: Observational study: case report. METHODS: An 8-month-old Arabian cross foal was anaesthetised for removal of the right alar fold and nasal plate. Anaesthesia was maintained with isoflurane in oxygen and lidocaine administered with a loading dose followed by a continuous rate infusion (CRI). The anaesthetic period was uneventful and 30 min before expected termination of the procedure lidocaine infusion was stopped. A sudden drop in mean arterial blood pressure was then observed. The ECG signal was lost, the end tidal CO2 tension dropped from 40 to 10 mmHg, corneal reflex was absent and asystole diagnosed. Cardiopulmonary resuscitation manoeuvres were immediately initiated, but epinephrine and atropine were unsuccessfully administered. Lipid emulsion was administered and the heart rate and arterial blood pressure gradually returned to normal. RESULTS: The foal recovered consciousness 3 h later, regained its sternal position, was responsive and 20 h later was able to stand up alone. MAIN LIMITATIONS: It will be necessary to evaluate a greater number of cases to determine the effectiveness of lipids in foals intoxicated with lidocaine. CONCLUSION: Intravenous lipid emulsion may be helpful in the treatment of potentially lethal cardiotoxicity attributable to lidocaine overdose in the foal.

Trochanteric hip fracture during cardioversion therapy. A case report.

INTRODUCTION: Trochanteric hip fractures in elderly patients with osteoporosis are commonly caused by low energy trauma. The cardioversion therapy is an extremely rare cause of this type of fracture. PRESENTATION OF CASE: We report the case of a woman with hip fracture after cardioversion. DISCUSSION: We discuss the production mechanism of this injury and the importance of the care of the osteoporotic bone under these therapies. CONCLUSION: The propofol sedation should be complemented with skeletal muscle relaxants in the cardioversion therapy to avoid hip fracture in select patients with osteoporosis.

Interprosthetic femoral fractures: Treatment with a lateral angular-stable plate. / Fracturas interprotésicas femorales. Tratamiento con placa lateral de estabilidad angular.

OBJECTIVE: To study the causes and outcomes of patients with interprosthetic femoral fractures. MATERIAL AND METHODS: A retrospective review conducted on 7 patients treated between 2010 and 2013. The knee arthroplasties had been implanted for at least 5 years, and those of the hip less than a year. They were bipolar cemented in 6 patients and totally non-cemented in one patient, all of them implanted due to a displaced femoral neck fracture. They were treated using osteosynthesis with angular stability plate covering the whole interprosthetic femoral segment. Except for one patient, all have been reviewed at least 12 months. RESULTS: The patients included 6 women and one man, with a mean age of 84.7. The fracture, always by low energy, occurred between 2 and 8 months after that of the hip without the implants being mobilized. Four of them were located at diaphyseal level, and 3 at supracondylar level, and unrelated to the type of knee implant. There was consolidation in all patients at a mean of 4.5 months, without a re-operation in any of them, and with no mortality during the follow-up period. All patients walked independently at the time of the fracture, and all of them have managed to return to walking independently, having lost as average 20° of knee flexion in cases of supracondylar fracture. CONCLUSIONS: The most important factors in our patients regarding the producing of the fracture have been the changes in the ability to walk after knee replacement and bone fragility. Angular stability plates give good results in the treatment of interprosthetic femoral fractures.

Computational flow cytometry reveals that cryopreservation induces spermptosis but subpopulations of spermatozoa may experience capacitation-like changes.

The reduced lifespan of cryopreserved spermatozoa in the mare reproductive tract has been attributed to both capacitative and apoptotic changes. However, there is a lack of studies investigating both phenomena simultaneously. In order to improve our knowledge in this particular point, we studied in raw and frozen-thawed samples apoptotic and capacitative markers using a wide battery of test based in flow cytometry. Apoptotic markers evaluated were caspase 3 activity, externalization of phosphatidylserine (PS), and mitochondrial membrane potential. Markers of changes resembling capacitation were membrane fluidity, tyrosine phosphorylation, and intracellular sodium. Conventional and computational flow cytometry using nonlinear dimensionally reduction techniques (t-distributed stochastic neighbor embedding (t-SNE)) and automatic classification of cellular expression by nonlinear stochastic embedding (ACCENSE) were used. Most of the changes induced by cryopreservation were apoptotic, with increase in caspase 3 activation (P < 0.01), PS translocation to the outer membrane (P < 0.001), loss of mitochondrial membrane potential (P < 0.05), and increase in intracellular Na+ (P < 0.01). Average values of markers of capacitative changes were not affected by cryopreservation; however, the analysis of the phenotype of individual spermatozoa using computational flow cytometry revealed the presence of subpopulations of spermatozoa experiencing capacitative changes. For the first time advanced computational techniques were applied to the analysis of spermatozoa, and these techniques were able to disclose relevant information of the ejaculate that remained hidden using conventional flow cytometry.

Histological findings in equine testes one year after standing laparoscopic peritoneal flap hernioplasty.

In order to know reproduction-related complications due to standing laparoscopic peritoneal flap hernioplasty, histological characteristics of the testicles from five stallions one year after surgery were compared with seven testicles from four healthy stallions. Moreover, the daily sperm output (DSO) was determined before (T0) and one year after surgery (T12). DSO did not show significant differences between T0 and T12. The diameter of the seminiferous tubules was significantly decreased in the samples from the hernioplasty group. The percentage of tubules with full spermatogenesis was smaller in the hernioplasty group, but the difference was not significant. It can be concluded that standing laparoscopic peritoneal flap hernioplasty produced mild histological changes in the testicular parenchyma, epididymis and pampiniform plexus after one year follow-up.

Standing laparoscopic peritoneal flap hernioplasty of the vaginal rings does not modify the sperm production and motility characteristics in intact male horses.

Laparoscopic hernioplasty techniques have been developed in the recent years to avoid the recurrence of inguinal hernias and to spare the testicles for breeding purposes in stallions. However, there have been no previous comprehensive and systematic studies of the reproductive outcomes and prognoses for stallions after inguinal hernioplasty. Therefore, the objective of this study was to assess the possible effects of one of these techniques (standing laparoscopic peritoneal flap hernioplasty) on the sperm production and motility characteristics of six healthy stallions that received this procedure based on 1-year follow-ups. There were no significant differences in the measured sperm variables (assessments based on the DSO, MOT, PMOT, VSL, VCL and VAP) during 1-year follow-ups.

Intra and postoperative assessment of re-sterilised Ligasure Atlas for orchidectomies in horses: clinical study.

Horses (n=35) underwent orchidectomy in a single institution with a re-sterilised LSA as sole means of haemostasis. During the surgery, the gross quality of the seal, the stickiness of the forceps to the tissues, bleeding/oozing from the stump and the need for a subsequent application in already severed spermatic cord were assessed for haemostasis quality. After surgery, physical parameters (appearance of the mucous membranes, quality of the peripheral pulse, heart rate, respiratory rate, rectal temperature and blood dripping from the incisions), haematology or packed cell volume and total protein were monitored to assess signs of bleeding or any other condition. For cleanliness and asepsis assessment, signs of surgical infection were recorded. Complications during surgery were mild degree of sticking of the LSA forceps to the tissues and dulling of the blade. There was no need to reapply LSA a second time except in one horse. This means a haemostasis complication rate of 2.85 per cent of the horses. No postoperative bleeding was detected. Only two horses with fever had associated signs of surgical site infection. This means an infection rate of 5.71 per cent of the horses.

[Final voluntary assessment for Traumatology and Orthopaedic Surgery medical residents: a report on the results and a look at the future]. / Evaluación final voluntaria para médicos residentes de Cirugía Ortopédica y Traumatología: balance de resultados y mirada al futuro.

INTRODUCTION: The idea of establishing an examination that accredits the training of the specialists in orthopaedic surgery at the end of their educational period as residents is subject to controversy. With the aim of encouraging the development of this examination, the present members of the National Commission of the Specialty of Orthopaedics (CNE) have reviewed the results obtained in previous examination. MATERIALS AND METHODS: The results of the voluntary final exam for Orthopaedics residents, and of the surveys of participant opinions for the years 2006 to 2011 are presented. RESULTS: The total number of participants was 231, growing from 19 in 2005, to 71 in 2011. The overall mean score in the period reviewed (2006-2011) was 6.72 out of 10 points. In these 6 years, 9 participants failed (4.25%). The mean score for the test was 7.57. The overall mean score of the oral exam was 6.57. The worst results were obtained in the general knowledge section of the oral examination. Nobody has ever failed the section on reconstruction of the lower extremity. The upper extremity section in the oral examination achieves the best average results. DISCUSSION: The examination has established its place in the structure of orthopaedic resident training in our country, even without making it official by the Administration. We must positively acknowledge those candidates who chose to take the examination and be evaluated by their peers in order to prove their qualification and distinction. This recognition will be the best encouragement for future generations.

A cholecystokinin-1 receptor agonist (CCK-8) mediates increased permeability of brain barriers to leptin.

BACKGROUND AND PURPOSE: Leptin regulates energy expenditure and body weight by acting both on the hypothalamus and on peripheral targets. Central actions of leptin are enhanced by cholecystokinin (CCK). The interaction between leptin and CCK makes physiological sense, as rats lacking CCK1 receptors are resistant to peripheral leptin but not to leptin directly infused into the brain. We have recently reported that CCK enhances leptin effects by increasing the entry of leptin into the CNS. The aim of this work was to further characterize the effect of CCK (10 microg kg(-1)) on leptin kinetics as well as the CCK receptor subtype involved in the interaction between CCK and leptin. EXPERIMENTAL APPROACH: Experiments were carried out both in free-feeding and in fasted rats receiving a single dose of leptin (100 microg kg(-1); i.p.). Parameters analysed over the next 6 h were plasma and cerebrospinal fluid concentrations of leptin. KEY RESULTS: We observed that CCK-8 depressed the increase in plasma leptin that followed the i.p. injection and simultaneously increased leptin concentration in the cerebrospinal fluid from 92+/-25 to 230+/-24 pg mL(-1) (P<0.05). The effect of CCK-8 was totally prevented by the CCK1 receptor antagonist, SR-27,897 (0.3 mg kg(-1), s.c.), but not by the CCK2 receptor antagonist, L-365,260 (1 mg kg(-1)). CONCLUSIONS AND IMPLICATIONS: These results show that CCK plays a role in regulating the access of leptin to the brain and suggest that CCK analogues, acting on CCK1 receptors, might be useful drugs in improving leptin actions within the brain.

Prolonged anesthesia with desflurane and fentanyl in dogs during conventional and laparoscopic surgery.

OBJECTIVE: To determine the effects of prolonged anesthesia with desflurane in dogs undergoing laparotomy or abdominal laparoscopy. DESIGN: Randomized prospective study. ANIMALS: 20 adult mixed-breed dogs. PROCEDURE: Dogs were randomly assigned to 1 of 2 groups with 10 dogs/group. Anesthesia was induced with propofol and maintained with desflurane and fentanyl, and pyloroplasty was performed. In 10 dogs, a ventral midline laparotomy was performed; in the other 10, abdominal laparoscopy was performed. Dogs were monitored for cardiovascular and respiratory responses (ECG, oxygen saturation [SpO2], arterial blood pressure, rectal temperature, end-tidal partial pressure of carbon dioxide [PETCO2], and expired desflurane concentration). Recovery times were recorded. RESULTS: Mean +/- SD duration of anesthesia was 201 +/- 25 minutes for dogs undergoing laparotomy and 287 +/- 15 minutes for dogs undergoing laparoscopy. Anesthesia was accompanied by hypotension that was less severe in dogs undergoing laparoscopy. Heart rate did not vary significantly during anesthesia. The SpO2 was > 97% in all dogs at all times, and PETCO2 remained within reference limits. Recovery times for dogs that underwent laparotomy were not significantly different from those for dogs that underwent laparoscopy. Mean +/- SD time to standing was 13.6 +/- 2.4 minutes for dogs that underwent laparotomy and 12.5 +/- 2.9 minutes for dogs that underwent laparoscopy. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that induction of anesthesia with propofol and maintenance with desflurane and fentanyl is safe in dogs undergoing abdominal surgery.