Inter- and intra-observer reliability of the new AO/OTA classification of proximal femur fractures.

INTRODUCTION: Hip fractures are a global health burden, with an incidence that is projected to increase from 66,000/year currently in the United Kingdom to 100,000/year by 2033. The classification of intertrochanteric fractures is key to the treatment algorithms advising on their surgical management. The AO/OTA classification is the most commonly used system, initially published in 1990 and subsequently shown to have poor inter- and intra-observer reliability, it was revised in 2018 with the main aim of re-classifying and further defining the 31-A2 group. METHODS: 150 plain film anteroposterior and lateral plain film radiographs of intertrochanteric fractures from three hospitals were classified using the 2018 AO/OTA classification of intertrochanteric fractures by six Orthopaedic Surgeons (2 Consultants, 4 Trainees), all were blinded to the definitive surgical treatment for patients. Radiographs were re-classified after a minimum of 3-months, Cohen's Kappa for inter-observer reliability was calculated from first round classifications and intra-observer reliability from first and second classifications. RESULTS: Mean Kappa for inter-observer reliability for AO group classification (e.g. 31-A1) was 0.479 (0.220 - 0.771, for sub-group classification (e.g. 31-A1.1) reliability reduced to 0.376 (0.276 - 0.613). Intra-observer reliability was comparable for both group and sub-group classifications, 0.661 and 0.587 respectively. CONCLUSIONS: The revised 2018 AO/OTA classification aimed to simply the classification of intertrochanteric fractures, however it remains unreliable with only a "moderate" inter-observer reliability at group level with this falling to "fair" when sub-group classifications are made. Identification of stable and unstable injuries using the new AO/OTA system remains fraught with difficulties and appears difficult to apply with consistent accuracy.

A cadaveric study showing the anatomical variations in the branches of the dorsalis pedis artery at the level of the ankle joint and its clinical implication in ankle arthroscopy.

Introduction Pseudoaneurysm formation following ankle arthroscopy is a rare but potentially catastrophic complication. The placement of anterior ankle portals carries inherent risk to the superficial and deep peroneal nerves, as well as to the dorsalis pedis artery. Anatomical variations in the dorsalis pedis and the presence of branches at the joint line may increase the risk of vascular injury and pseudoaneurysm formation during arthroscopy. There is limited anatomical evidence available regarding the branches of the dorsalis pedis artery, which occur at the point at which they cross the ankle joint. Objectives The objective of the study was to describe the frequency and direction of branches of the dorsalis pedis crossing the ankle joint. Materials and Methods Nineteen cadaveric feet were carefully dissected to explore the course of the dorsalis pedis artery, noting in particular the branching pattern at the joint line. Results Eleven of the nineteen feet had a branch of the dorsalis pedis artery that crossed the level of the ankle joint. Out of these, six were lateral, four medial and one bilateral. Eight of the eleven specimens had one branch at, or just before, the level of the joint. Two specimens had two branches and one had three branches crossing the ankle, which were all in the same direction, crossing laterally to the main trunk of the dorsalis pedis. Conclusions Our study demonstrated high rates of branching of the dorsalis pedis artery at the level of the ankle joint. The role of these branches in pseudoaneurysm formation during anterior hindfoot surgery remains unclear.

The recovery position for posterior surgery of the ankle and hindfoot.

Most posterior hindfoot procedures have been described with the patient positioned prone. This affords excellent access to posterior hindfoot structures but has several disadvantages for the management of the airway, the requirement for an endotracheal tube in all patients, difficulty with ventilation and an increased risk of pressure injuries, especially with regard to reduced ocular perfusion. We describe use of the 'recovery position', which affords equivalent access to the posterior aspect of the ankle and hindfoot without the morbidity associated with the prone position. A laryngeal mask rather than endotracheal tube may be used in most patients. In this annotation we describe this technique, which offers a safe and simple alternative method of positioning patients for posterior hindfoot and ankle surgery.

Sernbo score predicts survival after intracapsular hip fracture in the elderly.

INTRODUCTION: The Sernbo score uses four factors (age, social situation, mobility and mental state) to divide patients into a high-risk and a low-risk group. This study sought to assess the use of the Sernbo score in predicting mortality after an intracapsular hip fracture. METHODS: A total of 259 patients with displaced intracapsular hip fractures were included in the study. Data from prospectively generated databases provided 22 descriptive variables for each patient. These included operative management, blood tests and co-mobidities. Multivariate analysis was used to identify significant predictors of mortality. RESULTS: The mean patient age was 85 years and the mean follow-up duration was 1.5 years. The one-year survival rate was 92% (± 0.03) in the low-risk group and 65% (± 0.046) in the high-risk group. Four variables predicted mortality: Sernbo score >15 (p=0.0023), blood creatinine (p=0.0026), ASA (American Society of Anaesthesiologists) grade >3 (p=0.0038) and non-operative treatment (p=0.0377). Receiver operating characteristic curve analysis showed the Sernbo score as the only predictor of 30-day mortality (area under curve 0.71 [0.65-0.76]). The score had a sensitivity of 92% and a specificity of 51% for prediction of death at 30 days. CONCLUSIONS: The Sernbo score identifies patients at high risk of death in the 30 days following injury. This very simple score could be used to direct extra early multidisciplinary input to high-risk patients on admission with an intracapsular hip fracture.

Factors associated with survival after resection of colorectal adenocarcinoma in 314 patients.

BACKGROUND: An analysis of perioperative factors that were independently associated with survival up to 1000 days after scheduled colorectal adenocarcinoma resections in 314 patients. METHODS: The association of 16 perioperative variables with postoperative survival and critical care unit (CCU) admission after scheduled resections for colorectal adenocarcinoma between September 2005 and March 2009 was analysed using multivariable Cox regression analyses and Fisher's exact tests. RESULTS: We followed survivors for a mean of 983 days (range 696-1000 days). Average annual postoperative mortality was 8.5%, 14% after surgery performed in 2005, and 3% after surgery in 2009. Risk of mortality was independently associated with five variables after stratifying for date of surgery: attending a preoperative high-risk clinic [hazard ratio (HR) 0.42, P=0.006], worse World Health Organization performance status (HR 2.1, P=0.001), BMI (HR 0.92, P=0.009), higher nodal stage (HR 2.6, P<0.0001), and unplanned critical care admission (HR 7.2, P<0.0001). Patients who attended the preoperative clinic (207) were older, with worse renal function and ASA grade, than those who did not (107). Planned postoperative critical care admission was more common in patients who attended the high-risk clinic (24% vs 12%, P=0.01) and may have partly accounted for the observed mortality difference. CONCLUSIONS: Immediate perioperative care may have prolonged effects on postoperative survival. Specialized preoperative assessment clinics may reduce mortality after colorectal surgery.

Robot-assisted minimally invasive Kasai portoenterostomy: a survival porcine study.

BACKGROUND: Major enhancements offered by robotic surgery for minimally invasive procedure include tremor filtration, motion scaling, and the addition of a wrist to the instrument. Minor enhancements include indexing as well as safe and rapid instrument exchange. A benefit associated with any endoscopic procedure is magnification. It was hypothesized that these enhancements would allow the performance of complex gastrointestinal surgery. METHODS: Eight survival pigs (weight, 2.5-8 kg) underwent a robotically assisted minimally invasive portoenterostomy. The procedure was analogous to the Kasai portoenterostomy for biliary atresia usually performed for human patients at the age of 4 to 12 weeks. RESULTS: Five of the eight animals survived for more than 1 month after the operation, returning to normal eating and bowel habits in 2 to 3 days. None were jaundiced. All laboratory values were normal. At 1 month, the animals were killed. There was no anastomotic stenosis at either the end-to-side enteroenterostomy or the portoenterostomy. Histologically, the anastomoses were well healed. CONCLUSION: Computer-assisted robot-enhanced technology allows complex gastrointestinal surgery to be performed using minimally invasive techniques.

Perioperative management of calves undergoing implantation of a left ventricular assist device.

OBJECTIVE: To describe perioperative management of calves that underwent left lateral thoracotomy, aortic cross-clamping, partial left heart bypass and implantation of a left ventricular assist device. SAMPLE POPULATION: A total of 43 healthy castrated male calves, weighing 121 +/- 24 kg. RESULTS: Diazepam (mean +/- SD, 0.26 +/- 0.07 mg/kg), ketamine (5.9 +/- 2.17 mg/kg) and isoflurane were used in the anesthetic management of calves undergoing implantation of a left ventricular assist device in the descending thoracic aorta. Other adjunctive agents administered were fentanyl (11 +/- 5.4 microg/kg), lidocaine (4.9 +/- 3.19 mg/kg), bupivacaine (0.75%) and butorphanol (0.49 +/- 0.13 mg/kg). None of the calves regurgitated at induction or during intubation. A tube was used to drain the rumen and prevent bloat during the procedure. Partial left heart bypass was used to perfuse the caudal half of the body during the period of aortic cross clamp and device implantation. Initial mean systemic blood pressure was 96 +/- 25 mm Hg, and pressures measured in the auricular artery increased during aortic cross-clamping and bypass. Vasoconstrictor therapy was required to treat caudal arterial hypotension during the procedure in 9 calves. Mean systemic arterial pressures returned to baseline values by the end of the anesthetic period. Initial mean pulmonary arterial pressures (PAP) were 22 +/- 3 mm Hg. A significant but transient increase in pulmonary arterial pressure occurred after both heparin and protamine administration. CONCLUSIONS: The described anesthetic protocol was effective for thoracotomy and implantation of an intra-aortic left ventricular assist device in normal calves. Partial left ventricular bypass was a useful adjunct during the period of aortic cross clamp. The doses of heparin and protamine administered were effective. Responsibility to monitor oxygenation of the cranial half of the animal continues during the bypass period as hypoxemia due to pulmonary dysfunction will not be detected by the perfusionist.

Reduction of postsurgical adhesion formation in the rabbit uterine horn model with use of hyaluronate/carboxymethylcellulose gel.

OBJECTIVE: To assess the efficacy of a bioabsorbable gel for reducing primary postoperative adhesions. DESIGN: A randomized, prospective, blinded study. SETTING: Academic research environment. ANIMALS: Forty-one New Zealand Rabbits. INTERVENTION(S): A chemically modified hyaluronate and carboxymethylcellulose (HA/CMC) gel formulation was applied to a bilateral uterine horn injury. Postoperative adhesions were assessed at a second-look laparoscopy. MAIN OUTCOME MEASURE(S): The uterine horn model was shown to be adhesiogenic, with 29 (70%) of 42 untreated uterine horns found to have adhesions. After gel treatment, 22 (55%) of 40 uterine horns were free of adhesions compared with 12 (30%) of 42 controls. RESULT(S): Animals treated with HA/CMC gel had significantly reduced postsurgical adhesion scores when compared with controls. CONCLUSION(S): Treatment of injured uterine horn with HA/CMC gel resulted in a significant reduction in postoperative surgical adhesions.

Effects of interleukin-6 and its neutralizing antibodies on peritoneal adhesion formation and wound healing.

This study investigates the effects of preoperative IV administration of IL-6 and anti IL-6 on peritoneal adhesion formation and wound healing. Thirty-six male Sprague-Dawley rats (350-400 mg) were divided into three groups: control (group 1); IL-6 (group 2); and anti IL-6 (group 3). Under sterile conditions, all rats underwent a midline laparotomy. Ten cm2 of cecal serosa was abraded, the cecum further irritated with 0.1 ml of 70 per cent alcohol, and the incision closed in layers. At 3 weeks, peritoneal adhesions were graded using a score of 0 (none) to 3 (extensive, dense). Skin samples from incisional sites were examined tensiometrically (true stress and true strain), biochemically (collagen content), and histologically. Adhesion formation score was significantly increased in IL-6 group (2.78 +/- 0.44, Mean +/- SD) and decreased in anti IL-6 group (1.40 +/- 0.52) compared to control (2.00 +/- 0.50). (P < 0.03 by Kruskal Wallis test). There was no significant difference in true stress, true strain, and collagen content between the two treatment groups and controls at the 0.05 level by ANOVA. Histological analysis showed higher number of inflammatory cells and fibroblasts in IL-6 treated groups. We conclude that IL-6 plays a major role in peritoneal adhesion formation. Selective immunosuppression, using IL-6 neutralizing antibodies preoperatively, leads to a reduction of such adhesion formation without a significant effect on wound healing.

Preoperative administration of antibodies against tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) and their impact on peritoneal adhesion formation.

This study investigates the effects of preoperative intravenous administration of antibodies against TNF-alpha and IL-1 on peritoneal adhesion formation. Fifty-six Sprague-Dawley rats (350-400 gm) were used in this study. Eight rats were used to empirically determine the amount of anti TNF-alpha and anti IL-1 needed for complete in vivo neutralization. This amount was used for preoperative treatment of selected groups. Forty-eight rats were divided into four equal groups (n = 12). All rats underwent a midline laparotomy. Ten cm square of cecal serosa was abraded, the peritoneal cavity was irrigated with normal saline, and the incision was closed in layers. Cultures were obtained intraoperatively and rats with positive cultures were excluded. Rats in Group 1 were not treated (control), while rats in Groups 2, 3, and 4 were treated with anti TNF-alpha, anti IL-1, and a combination of anti TNF-alpha and IL-1 respectively. All rats were killed at 3 weeks, and peritoneal adhesions were graded using a scale of 0 (none) to 3 (extensive, dense). Rats treated with anti IL-1 (Group 3) and those treated with a combination of anti TNF-alpha and anti IL-1 (Group 4) had significantly fewer adhesions when compared with Group 1 (control) (P < 0.01 and < 0.005, respectively). Least adhesion formation was associated with Group 4 rats. In conclusion, selective immunosuppression, at a molecular level, appears to have a significant impact on rates of postoperative peritoneal adhesion formation.

Chronic central vein catheterization for intraoperative and long-term venous access in swine.

Chronic venous access and repeated blood sampling for research purposes in large swine ideally should be possible without sedation, restraint or direct venipuncture of deep vessels. An operative technique of cranial vena cava catheterization and chronic catheter maintenance methods are described which were used successfully in the placement of 11 silicone rubber catheters in 10 animals. All were used for repeated blood sampling, as well as intraoperative infusion of medications and large fluid volumes. Long term patency was excellent with 10 catheters patent at the end of the study interval, up to 14 weeks after insertion. Serial blood sampling was accomplished easily without restraint. Catheter damage, infection or malfunction was rare. Proper maintenance and careful aseptic blood sampling render the cranial vena cava catheter a safe and reliable alternative to direct venipuncture in swine.

Calcium homeostasis after parathyroidectomy in normal and shocked states.

The natural history of parathyroidectomy was studied for 75 weeks in two dogs. After parathyroidectomy, the dogs required intravenous and intramuscular calcium supplementation for 1 week. Despite calcium supplementation, in 2 weeks the ionized calcium (Ca++) level fell from 4.67 mg/dl to 2.39 mg/dl. The Ca++ level rose to 4.25 mg/dl by 7 weeks after which the intramuscular calcium supplement was gradually weaned so that no calcium was given after 20 weeks. The Ca++ level stabilized at 3.15 to 3.25 mg/dl after 20 weeks. Postoperative parathormone (PTH) levels remained low. The response to hemorrhagic shock in these two calcium-independent dogs was compared with that seen in two calcium-dependent dogs 4 weeks after parathyroidectomy and to that seen in two euparathyroid dogs. Shock caused a sharp decrease in Ca++ in all animals that had parathyroid ectomy. Prostaglandin E2 (PGE2) was elevated preoperatively in these dogs and fell markedly during shock. Ca++ remained normal and PGE2 increased slightly after shock in the euparathyroid dogs. Cardiac output rose with resuscitation in the euparathyroid dogs but remained constant in the calcium-dependent dogs and increased slightly in the calcium independent parathyroidectomized animals. PTH levels were low in the parathyroidectomy groups and did not react to shock. PTH increased markedly after resuscitation in the euparathyroid dogs, suggesting its role as an acute-phase hormone. All levels returned to baseline levels within 3 days after shock. Adaptation to hypocalcemia occurs in parathyroidectomized dogs and involves PGE2 as well as other factors. Hemorrhagic shock exceeds this compensatory response which in euparathyroid dogs involves active PTH release in response to hypocalcemia.

Spatulated versus end-to-end anastomosis for small vessel injury.

Spatulated anastomosis (SA) was compared to end-to-end anastomosis (EEA) with small arteries (3-4 mm) in nine conditioned dogs (22-30 kg). A 1-cm segment of both common femoral arteries with an average of 3.5-mm external diameter was resected and reconstructed by EEA and by contralateral SA using a running suture of 5/0 proline. Pre- and postoperative flow rates, flow rates at 1 year in three dogs, arteriography at 1 year in six dogs, and gross examination at 1 year were done. The preoperative flow rates averaged 86 ml/min for the SA and 76 ml/min for the EEA; early postoperative flow rates averaged 100 ml/min and 92 ml/min, respectively, whereas 1-year flow rates averaged 63 ml/min and 57 ml/min, respectively. None of these differences is significant. Preoperative and 1-year external diameters averaged 3.54 mm and 3.39 mm in the SA group compared to 3.5 mm and 3.44 mm in the EEA group. Arteriograms showed good flow except for slight narrowing in one SA which, on postmortem exam, was seen to result from a fibrous band which extended from the spatulated segment to the opposite wall. These data show that SA and EEA yield comparable results both acutely and long term. The choice of EEA versus SA for primary repair of injured small vessels should be determined by surgical preference.

The beneficial role of calcium supplementation during resuscitation from shock.

The role of calcium (Ca) in resuscitation from hemorrhagic shock is controversial and in the present report three regimens were compared: supplementation (Ca-S), avoidance (No-Ca), and Ca channel blockade (Ca-B). This was studied in 40 splenectomized dogs subjected to reservoir shock (MAP 60 torr/90 min, then 40 torr/30 min) and treated with: a) 20 ml/kg balanced electrolyte solution (BES); b) shed blood; c) 30 ml/kg BES; and d) 250 ml autologous bank blood. Three groups of six dogs received Ca-S (0.5 mEq/kg), No-Ca, or Ca-B (verapamil 0.15 mg/kg) in BES. Postoperative therapy of 50 ml/kg/d BES with Ca-S, No-Ca, or Ca-B was given for 3 days. The effects of parathyroidectomy (P) via wide thyroidectomy in 22 dogs treated with calphosan (20 ml/d) and L-thyroxin (0.02 mg/kg) preceding shock was also studied as above: Ca-S/P, No-Ca/P, and Ca-B/P; four sham dogs had anesthesia but no shock (Anes/P). Studies done before, during, and after shock and on day three included systemic pressures (MAP), central pressures (CFP), cardiac output (CO), resistance (SVR), heart work (LVW), and outcome. Post-resuscitation Ca was significantly less in all groups (1.6-3.7 mg%) compared to Ca-S (4.8 mg%). Compared to Ca-S dogs, the post-resuscitation studies in the No-Ca and Ca-B dogs showed lower MAP, CO, and LVW in both intact and hypoparathyroid animals. Post-resuscitation CFP was also lower in the Ca-S and Ca-S/P dogs compared to the other euparathyroid and hypoparathyroid dogs. Death after the initiation of resuscitation occurred in two No-Ca/P and three Ca-B/P dogs. These data suggest that calcium supplementation plus an intact calcium-parathyroid axis enhance the resuscitation effort.

Mechanisms of impaired renal function with PEEP.

Deterioration in renal function associated with positive end-expiratory pressure (PEEP) has been attributed to renal hypoperfusion from the fall in cardiac output and mean arterial blood pressure. Using a canine in vivo model, renal function was measured during control, zero end-expiratory pressure (ZEEP), and PEEP (5, 10, and 15 cm H2O) ventilatory cycles, while renal blood flow was maintained constant with a pump. High PEEP (15 cm H2O) led to a rise in renal vein pressure (RVP) and a fall in mean arterial pressure (MAP). PEEP resulted in no change in glomerular filtration rate (GFR) or solute exertion; however, free-water clearance (FWC) became less negative in the 15-cm H2O PEEP group. Intrarenal autoregulation maintains GFR during ventilation with PEEP when renal blood flow is constant, supporting the view that altered filtration and solute excretion clinically is secondary to changes in aortic pressure and renal perfusion.

Cholecystoenteric anastomosis with the EEA stapler for cancer of the pancreas.

The integrity of a stapled anastomosis of the small bowel to the gallbladder with malignant distal biliary obstruction was investigated. Seven dogs were studied during a 52 week period following completion of a cholecystoenterostomy (Roux-Y) with an EEA stapler for bypass of a ligated common bile duct. A widely patent and secure anastomotic line was documented. Three human patients with unresectable cancer of the head of the pancreas who underwent stapled cholecystojejunostomies received excellent palliation as well. Cholecystojejunostomy with the EEA stapler is a rapid and safe procedure for unresectable, malignant distal biliary obstruction.

Stimulation of deoxythymidine incorporation in the colon of rats treated intrarectally with bile acids and fats.

The incorporation of tritiated deoxythymidine ([3H]dThd) into colonic DNA of male Sprague-Dawley rats treated intrarectally (i.r.) with bile salts and other substances has been investigated. Instillation of sodium deoxycholate caused an increase in the incorporation of [3H]dThd which was maximal 12 h after treatment. The level of incorporation showed a steep linear dose response from 0.5 mM to 15 mM bile salt. Higher concentrations of deoxycholate up to 300 mM only slightly increased the extent of incorporation when compared to the lower concentration. Several other substances also increased the extent of [3H]dThd incorporation; these include: chenodeoxycholate, lithocholate, sodium dodecyl sulfate, dioctyl sulfosuccinate, corn oil, beef fat, and trioctanoin. Substances which had no effect on [3H]dThd incorporation include cholesterol, dehydrocholate, sodium acetate, dextrose, and mineral oil. Many of the agents which increase colonic [3H]dThd incorporation are also known to enhance colonic tumorigenesis. These findings indicate similarities between the short-term effects, in their respective target tissues, of colon tumor promoters, and classical mouse skin tumor promoters.

Chronic intracarotid cannulation of pigeons for administration of behaviorally active peptides.

Chronic intracarotid cannulation of the common carotid artery was performed in the pigeon. The catheter system of polyethylene tubing consisted of an indwelling component and an injection component. The indwelling component was exteriorized at the occiput so the bird could not reach the catheter with its beak. Following surgery, the pigeons were housed individually and received food and water ad libitum and no special care was necessary. The catheter was flushed daily with heparin in 0.9% NaCl solution to maintain patency. 30 pigeons were continuously or intermittently infused with bioactive peptides for up to 60 days after cannulation.

Use of allograft amniotic membrane for control of intra-abdominal adhesions.

The authors have studied 60 rabbits to determine the effect and fate of allograft amniotic membranes (devoid of chorion) used in the intra-peritoneal cavity to control adhesions secondary to bowel perforation and bacterial contamination. The experimental animals revealed dramatic differences when compared to the control with major reduction in adhesions. Abscesses remained localized and contained. No untoward reactions were noted in the host. Violent immunologic rejection did not occur. The membranes gradually disintegrated and left little or no evidence of its presence. Important clinical applications are obvious.