OPTN/SRTR 2018 Annual Data Report: Deceased Organ Donation.

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2018, there were 10,721 deceased donors, and this number has been increasing since 2010. The number of deceased donor transplants increased to 29,676 in 2018 from 28,582 in 2017, and this number has been increasing since 2012. The recent increase may be due in part to the rising number of deaths of young people due to the opioid epidemic. In 2018, 4994 organs were discarded, slightly more than 4813 in 2017. In 2018, 3755 kidneys, 278 pancreata, 707 livers, 3 intestines, 23 hearts, and 317 lungs were discarded. These numbers suggest an opportunity to increase numbers of transplants by reducing discards.

OPTN/SRTR 2018 Annual Data Report: Heart.

The new adult heart allocation policy was approved in 2016 and implemented in October 2018, so its effect was not yet evident in 2018 data. However, the more granular data being collected are anticipated to allow for improved analyses. In 2018, new listings continued to increase; 3883 new adult and 685 new pediatric candidates were added. In 2018, 3440 heart transplants were performed, an increase of 167 over 2017; 473 transplants occurred in pediatric recipients and 2967 in adult recipients. Short-term and long-term posttransplant mortality improved. Overall 1-year survival for adults who underwent heart transplant in 2011-2013 was 90.3%, 3-year survival was 84.7%, and 5-year survival was 79.6%. Mortality rates for pediatric recipients were 4.5% at 6 months and in 5.9% at 1 year posttransplant, 12.5% at 3 years for transplants in 2014-2015, 14.8% at 5 years for transplants in 2012-2013, and 29.8% at 10 years for transplants performed in 2008-2009.

OPTN/SRTR 2017 Annual Data Report: Heart.

In 2017, 3273 heart transplants were performed in the United States. New listings continued to increase, and 3769 new adults were listed for heart transplant in 2017. Over the past decade, posttransplant mortality has declined. The number of new pediatric listings increased over the past decade, as did the number of pediatric heart transplants, although some fluctuation has occurred more recently. New listings for pediatric heart transplants increased from 481 in 2007 to 623 in 2017. The number of pediatric heart transplants performed each year increased from 330 in 2007 to 432 in 2017, slightly fewer than in 2016. Short-term and long-term mortality improved. Among pediatric patients who underwent transplant between 2015-2016, 4.8% had died by 6 months and 6.2% by 1 year.

OPTN/SRTR 2016 Annual Data Report: Heart.

In 2016, 3209 heart transplants were performed in the United States. New, active listings increased 57% since 2005. The number of adult heart transplant survivors continued to increase, and in 2016, 30,622 recipients were living with heart transplants. Patient mortality following transplant has declined. The number of pediatric candidates and transplants performed also increased. New listings for pediatric heart transplants increased from 454 in 2005 to 624 in 2016. The number of pediatric heart transplants performed each year increased from 319 in 2005 to 445 in 2016. Among pediatric patients who underwent transplant in 2015, death occurred in 5.9% at 6 months and 7.2% at 1 year.

A novel method for defining the Greyhound talocrural joint axis of rotation for hinged transarticular external skeletal fixation.

In order to apply hinged transarticular external skeletal fixation for stabilization of the injured canine tarsal joint, knowledge of the three-dimensional (3D) location and orientation of the transverse axis is necessary. This method of immobilization may be used as a primary or adjunctive method of stabilisation for a large number of traumatic conditions. Using pin-mounted markers in the cadaveric Greyhound crus and talus, a closed-form solution of absolute orientation was used to identify, on radiographs, the lateral and medial locations of the transverse axis by tracking the 3D excursions of the markers during flexion and extension. A line was drawn across the dorsal aspect of the calcaneus from the most dorsal point on the distal articular surface(proximal intertarsal joint: PIJ) to the most dorsal point on its proximal articulation with the body of the talus, and the location of the centre of rotation was expressed in terms of the length of that line. In seven Greyhound tarsal joints, the medial end of the axis was located 73 ± 10% proximal to the PIJ and 11 ± 7% dorsal to the line. The lateral end was 73 ± 9% proximal tothe PIJ and -2 ± 3% plantar to the line.

Mechanisms of thermal balance in flying Centris pallida (Hymenoptera: Anthophoridae).

Thermoregulation of the thorax is critical for bees and other endothermic insects to achieve high rates of flight muscle power production. However, the mechanisms allowing insects to regulate thorax temperatures during flight are not well understood. To test whether variations in metabolic heat production, evaporation or heat transfer from the thorax to the abdomen contribute to the maintenance of stable body temperatures during flight in the bee Centris pallida, we measured CO2 production, water vapor loss, wingbeat frequency and body segment temperatures during flight at varying air temperatures (Ta). While hovering in the field and while flying in the respirometer, C. pallida males maintain extremely stable, elevated thorax temperatures (45+/-2 degrees C; mean +/- S.E.M.). Measurements of head, thorax and abdomen temperatures as a function of Ta during hovering flight in the field indicated that C. pallida males were not actively increasing heat transfer from the thorax to the head or abdomen at high Ta values. As Ta increased from 26 to 35 degrees C, increases in evaporative water loss were relatively small compared with the decrease in carbon dioxide emission. As Ta values increased from 26 to 35 degrees C, the factorial decreases in metabolic heat production and the elevation of thorax temperature above Ta were closely matched (35 %), suggesting that variation in metabolic heat production is the major mechanism of thermoregulation in flying C. pallida. The thermal effects on rates of water loss and metabolic water production resulted in a strong positive water balance at cooler Ta values, but a strong negative water balance at Ta values above 31 degrees C. During the first minute of flight in the respirometry chamber, wingbeat frequency was independent of Ta. However, by the fourth minute, there was a significant negative relationship between Ta and wingbeat frequency, which was similar to the thermal relationship observed for wingbeat frequency in the field. These data suggest that, either through homeostatic regulation or resulting secondarily from thermal effects on flight motor properties, variation in metabolic heat production may occur via altered wingbeat kinematics.

Acid-base status and spiracular control during discontinuous ventilation in grasshoppers

Many insects ventilate discontinuously when quiescent, exhibiting prolonged periods during which little or no gas exchange occurs. We investigated the consequences of discontinuous ventilation (DV) on haemolymph acid­base status and tested whether spiracular opening during DV is due to changes in internal gas tensions in the western lubber grasshopper Taeniopoda eques. At 15 °C, resting T. eques exhibited interburst periods of about 40 min. During the interburst period, haemolymph PCO2 rose from 1.8 to 2.26 kPa, with minimal acidification of haemolymph. Animals in atmospheres in which PCO2 was 2 kPa or below continued to exhibit DV, while atmospheres in which PCO2 was 2.9 kPa or above caused cessation of DV. These data indicate that accumulation of internal CO2 to threshold levels between 2 and 2.9 kPa induces spiracular opening in grasshoppers. In contrast to the situation in lepidopteran pupae, variation in atmospheric PO2 had no effect on interburst duration. Relative to lepidopteran pupae, the internal PCO2 of grasshoppers during DV is threefold lower, the PCO2 required for triggering spiracular opening is also threefold lower, and the open phase spiracular conductance is at least tenfold higher, demonstrating that considerable diversity exists in these aspects of insect respiratory physiology.

Dennyson-Fulford subtalar arthrodesis.

Forty-six patients who had undergone Dennyson-Fulford subtalar arthrodesis for hindfoot valgus deformities secondary to various pathologies were reviewed both radiographically and clinically. Mean age at surgery was 7.67 years; mean follow-up was 5.67 years. Evaluation showed 70% good, 20% fair, and 10% poor results. Pseudarthrosis rate was 6.4%, and was not necessarily related to undercorrection or progressive deformity. Screw sclerosis, which is common, is associated with pseudarthrosis, but not with hardware failure. Hardware problems can be anticipated with intraoperative radiographs, and penetration of the lateral calcaneal cortex up to 1.0 cm is well tolerated.

Refracture of adolescent femoral shaft fractures: a complication of external fixation. A report of two cases.

Malunion is often a problem in adolescent femoral shaft fractures treated with traction and subsequent casting. We used external fixation as an alternative treatment method to control alignment and allow early mobilization. After fracture healing and fixator removal, two patients experienced refracture. This unusual complication is the basis of our report. Prolonged rigid or static fixation appears to be detrimental to sufficient callus formation and healing.

Knee motion following multiple soft-tissue releases in ambulatory patients with cerebral palsy.

Multiple soft-tissue releases (MSTRs) in cerebral palsy have been advocated to improve knee motion during gait. Forty-five extremities underwent MSTRs as recommended by preoperative gait analysis. Pre- and postoperative analyses were evaluated in relation to knee motion and foot progression angle. Maximum knee flexion during swing and the foot progression angle showed no significant change postoperatively. The total knee ROM and minimum knee flexion in stance improved significantly towards normal. The timing of maximum knee flexion and slope of the knee flexion curve at toe off improved with respect to age and number of previous surgeries. MSTRs increased knee ROM and improved the sequential timing and event progression during gait.

The effects of contact pressure elevations and aseptic necrosis on the long-term outcome of congenital hip dislocation.

The relationship between excessive articular contact pressure, aseptic necrosis, and the long-term outcome with unilateral congenital dislocation of the hip (CDH) was studied in a series of 84 patients treated by closed reduction and followed for an average of 29.2 years. Contact stress was estimated from archived radiographs taken at the time of maturity and at several follow-up visits. At a recent review, each patient was rated both clinically for pain and function and radiographically for deformity, degeneration, and aseptic necrosis. For each of 431 archived films, articular contact stress (force/area) was estimated mathematically, based upon a frontal plane equilibrium (force) analysis and a landmark-based inference of three-dimensional head surface (area). Good correlation with final deformity (Spearman rho = 0.78) was obtained when the hips were ranked in terms of a new cumulative overpressure index Pc, defined as a time-pressure product involving years of pressure exposure beyond a 2 MPa pressure damage level. An unsatisfactory outcome occurred in 90.4% of the hips experiencing Pc greater than 10 MPa-years (most of which had aseptic necrosis involvement), whereas the outcome was satisfactory in 80.9% of hips with Pc less than 10 MPa-years.

Ender rods versus external fixation in the treatment of open tibial fractures.

This is a retrospective nonrandomized study of 66 open tibial fracture patients that compares comparable population treated at one trauma center. The fractures were treated with either Ender rods or external fixation. Of these, 29 fractures were eliminated from the study due to incomparable variables. Thus, the study group consisted of a total of 37 tibial fractures: 20 treated by Ender rods and 17 treated by external fixation. Open tibial fractures treated with Ender rods had a significantly lower number of complications than those treated with external fixation. The group treated with Ender rods also had a significantly lower number of surgical procedures per patient in Grades I and II open tibial fractures. There were no statistical differences regarding weeks to union or hospital days. Ender rods are superior to external fixation removed early in the treatment of Gustilo's Grades I, II, and IIIA open fractures with either stable or unstable fracture configuration (Orthopaedic Trauma Association Grades IA-IC, IIA-IID, and IIIA-IIIC). Perhaps future study will allow sufficient numbers to determine whether Ender rods can be used in Grades IIIB and IIIC open tibial fractures, but there are no data at this time to support this conclusion.

Unstable intertrochanteric/subtrochanteric fractures of the femur.

The unstable intertrochanteric/subtrochanteric fracture, as identified by the modified Müller classification, should be considered a separate entity with its own problems. It can be highly unstable; none of the orthopedic appliances has been designed with this fracture in mind. Compression screws yield better results than Enders rods in these fractures. However, eight patients (16%) in this study who were treated with a compression screw did have a complication. Thus, further studies need to be done to develop other orthopedic appliances for these unstable fractures. Enders rods and compression screws were used to treat 72 unstable intertrochanteric/subtrochanteric fractures. The type of surgical procedure was determined by the surgeon. Anesthesia time and blood loss were significantly lower in the group treated with the Enders nail. Intraoperative and postoperative complications of the Enders group were reported in four (20%) and eight patients (32%), respectively, as compared to zero and eight patients (16%) in the compression screw group. Postoperative time to ambulation, knee pain, and reoperation rate were significantly higher in those treated with the Enders nail. Fracture reduction and ideal device position were acceptable in only 16 patients (64%) and four patients (16%) of the Enders group, respectively, compared with 46 patients (98%) and 40 patients (86%) in the compression screw group.

Effects of sleeping with the bed-head raised and of ranitidine in patients with severe peptic oesophagitis.

Sleeping with the bed-head raised is commonly recommended as treatment for patients with troublesome oesophagitis, but its effect has not been objectively tested. Ranitidine therapy is useful in oesophagitis, but it does not often produce complete relief of symptoms. The effects of each of these treatments alone and in combination have been studied in 71 patients with severe (grade III) peptic oesophagitis. Each treatment improved both symptoms and endoscopic appearances significantly more than placebo did. However, the combination of the two treatments was much better than either alone; the reduction in pain score and the area of ulceration healed were about twice those with either treatment alone. Smoking more than five cigarettes per day or drinking more than 30 g alcohol per day significantly reduced the effectiveness of ranitidine therapy, but age, sex, body weight, or the presence of a hiatus hernia had no detectable effect.

Microhabitat segregation and physiological differences in co-occurring tiger beetle species, Cicindela oregona and Cicindela tranquebarica.

The daily movements of two co-occurring tiger beetle species were monitored in conjunction with changes in microclimate along streams in Northeast Arizona. Cicindela oregona and C. tranquebarica temporarily segregated across areas of beach exhibiting different microclimates. C. oregona progressively moved from the dry upper beach to the wet stream edge as beach temperatures increased and humidity decreased. The actively foraged throughout the day in this moist habitat at air temperatures between 25 and 38°C. C. tranquebarica remained on the dry, upper portions of the beach and shuttled between sun and shade at air temperatures above 35°C. Only when stream edge temperatures exceeded 30°C was tranquebarica found in this subhabitat. Both species exhibited physiological tolerances in the laboratory that were consistent with their microhabitat preferences in the field. Although both species had similar high lethal temperatures (47-48°C) in saturated air, oregona died at lower temperatures (39-43°C) than tranquebarica (46-47°C) under dry (0% RH) conditions. C. oregona was considerably more active than tranquebarica at body temperatures below 30°C and exhibited higher levels of active metabolism between 25 and 40°C. In addition, C. tranquebarica exhibited significantly lower water loss rates than oregona at 30, 35 and 40°C.

Flexible intramedullary nailing of subtrochanteric fractures of the femur. A multicenter analysis.

In a retrospective, multicenter analysis, 79 subtrochanteric fractures of the femur were treated with flexible intramedullary nails. Seventy fractures were traumatic in origin, three were pathologic, and six occurred in spinal cord patients. All of the fractures healed, and there were no fixation failures. Thirteen patients (16%) required adjunctive internal fixation, bone grafts, or postoperative traction. Shortening greater than 1 cm occurred in four patients (5%). Reoperation with one week of surgery was necessary in eight patients (10%). The single greatest complication was knee complaints, which occurred in 17 patients (21.5%). However, only six of these patients required revision prior to fracture union. In one patient a deep wound infection developed, which eventually healed without evidence of osteomyelitis. All patients who were ambulatory before their fracture were able to bear weight.