[Operative treatment of the unicompartmental knee arthritis - results of a nationwide survey in 2008]. / Operative Therapie der unikompartimentellen Gonarthrose - Resultate einer bundesweiten Umfrage für das Jahr 2008.

BACKGROUND: Despite good long-term results of primary total knee arthroplasty, it is a commonly accepted aim to stave off joint replacement as long as possible, particularly in younger patients. In this situation the surgeon has to make a careful decision whether an arthroscopic procedure will be promising, a corrective osteotomy may be sensible or a joint replacement due to the patient's age is acceptable. High tibial osteotomy had become increasingly popular by use of the opened wedge technique combined with locking compression plates fixation in the past decades while it has been replaced step by step by total knee arthroplasty. In spite of this fact the German national agency of quality management (BQS) showed that the number of total knee replacements in Germany increased from 90 000 in 2003 to 146 000 in 2008. The share of unicompartmental knee replacements in this period doubled from 5.3 % to almost 10 %. The aim of the present study was to inquire current data regarding particular surgical treatment concepts of unicompartmental knee arthritis in Germany. MATERIAL AND METHODS: In a nationwide anonymous survey in May 2009 220 departments of orthopaedics and 230 departments of trauma surgery were asked about their treatment strategies in unicompartmental knee arthritis in middle-aged patients (30 to 60 years) with unilateral Outerbridge grade III-IV lesions. Overall 46 questions in 6 subject areas (structure of the department, number of treated patients, surgical methods, anaesthesiological procedures, perioperative management, postoperative treatment) were posed. With regard to the item "operative treatment" we asked for the importance of arthroscopic procedures, corrective osteotomies and different procedures of joint replacement. The interpretation was done with invariant data analysis by indication of numerical frequency and percentage distribution of selected options. RESULTS: Questionnaires were returned by 51.1 % of the surveyed departments. This represents a total number of 76,028 procedures in unicompartmental knee arthritis in middle-aged patients. First of all, arthroscopic procedures were applied (50.4 %), followed by knee replacements (43.4 %, of which 87.3 % were total knee replacements, 12.3 % unicompartmental knee replacements and 0.4 % tibial hemiarthroplasties) and corrective osteotomies (6.1 %). In 59.8 % of the 38,376 arthroscopic procedures a microfracturing and in 28.2 % an abrasion arthroplasty was done. Most of the corrective osteotomies were performed at the proximal tibia (90.9 %) using an open wedge technique (73 %) and internal fixation with locking compression plates (72 %). 75.2 % of the responders performed cemented unicompartmental arthroplasties (97.8 %) with an average number of 23.2 per year. 43.4 % believe that bicompartmental arthroplasty in case of additional affection of the femoropatellar joint is an option and 22.6 % believe in the expected advantages of patient-specific unicompartmental implants. Total knee arthroplasties are performed with an average of 197.4 per year, most frequently using the free-hand technique (85.5 %) and medial-parapatellar approach (82 %). Interpositional knee devices were only used in 9.1 % of responding departments with an average number of 6.6 per year. Only procedures with low difficulty level such as arthroscopies were done by residents in a higher number (16.9 %). Procedures with higher difficulty level were mainly done by consultants, senior or chief surgeons. CONCLUSION: In total, arthroscopic procedures still play an essential role in the treatment of unicompartmental knee arthritis prior to joint replacement. Total knee arthroplasty was preferred even though the number of unicompartmental knee replacements was only slightly increasing. Periarticular corrective osteotomies have gained in importance since the introduction of locking compression plates. Interpositional knee devices play a minor role in the treatment of unilateral knee arthritis in Germany.

Effect of sorghum-sudangrass and velvetbean cover crops on plant-parasitic nematodes associated with potato production in Florida.

In a 3-year field study, population densities of Belonolaimus longicaudatus and other plant-parasitic nematodes and crop yields were compared between potato (Solanum tuberosum) cropping systems where either sorghum-sudangrass (Sorghum bicolor x S. arundinaceum) or velvetbean (Mucuna pruriens) was grown as a summer cover crop. Population densities of B. longicaudatus, Paratrichodorus minor, Tylenchorhynchus sp., and Mesocriconema sp. increased on sorghum-sudangrass. Population densities of P. minor and Mesocriconema sp. increased on velvetbean. Sorghum-sudangrass increased population densities of B. longicaudatus and Mesocriconema sp. on a subsequent potato crop compared to velvetbean. Potato yields following velvetbean were not greater than following sorghum-sudangrass despite reductions in population densities of B. longicaudatus.

Yield Reduction and Root Damage to Cotton Induced by Belonolaimus longicaudatus.

Sting nematode (Belonolaimus longicaudatus) is recognized as a pathogen of cotton (Gossypium hirsutum), but the expected damage from a given population density of this nematode has not been determined. The objective of this study was to quantify the effects of increasing initial population densities (Pi) of B. longicaudatus on cotton yield and root mass. In a field plot study, nematicide application and cropping history were used to obtain a wide range of Pi values. Cotton yields were regressed on Pi density of B. longicaudatus to quantify yield losses in the field. In controlled environmental chambers, cotton was grown in soil infested with increasing Pi's of B. longicaudatus. After 40 days, root systems were collected, scanned on a desktop scanner, and root lengths were measured. Root lengths were regressed on inoculation density of B. longicaudatus to quantify reductions in the root systems. In the field, high Pi's (>100 nematodes/130 cm(3) of soil) reduced yields to near zero. In controlled environmental chamber studies, as few as 10 B. longicaudatus/130 cm(3) of soil caused a 39% reduction in fine cotton roots, and 60 B. longicaudatus/130 cm(3) of soil caused a 70% reduction. These results suggest that B. longicaudatus can cause significant damage to cotton at low population densities, whereas at higher densities crop failure can result.

Population Dynamics of Belonolaimus longicaudatusin a Cotton Production System.

Belonolaimus longicaudatus is a recognized pathogen of cotton (Gossypium hirsutum), but insufficient information is available on the population dynamics and economic thresholds of B. longicaudatus in cotton production. In this study, data collected from a field in Florida were used to develop models predicting population increases of B. longicaudatus on cotton and population declines under clean fallow. Population densities of B. longicaudatus increased on cotton, reaching a carrying capacity of 139 nematodes/130 cm(3) of soil, but decreased exponentially during periods of bare fallow. The model indicated that population densities should decrease each year of monocropped cotton, if an alternate host is not present between sequential cotton crops. Economic thresholds derived from published damage functions and current prices for cotton and nematicides varied from 2 to 5 B. longicaudatus/130 cm(3) of soil, depending on the nematicide used.

Effects of potato-cotton cropping systems and nematicides on plant-parasitic nematodes and crop yields.

Belonolaimus longicaudatus has been reported as damaging both potato (Solanum tuberosum) and cotton (Gossypium hirsutum). These crops are not normally grown in cropping systems together in areas where the soil is infested with B. longicaudatus. During the 1990s cotton was grown in a potato production region that was a suitable habitat for B. longicaudatus. It was not known how integrating the production of these two crops by rotation or double-cropping would affect the population densities of B. longicaudatus, other plant-parasitic nematodes common in the region, or crop yields. A 3-year field study evaluated the viability of both crops in monocropping, rotation, and double-cropping systems. Viability was evaluated using effects on population densities of plant-parasitic nematodes and yields. Rotation of cotton with potato was found to decrease population densities of B. longicaudatus and Meloidogyne incognita in comparison with continuous potato. Population densities of B. longicaudatus following double-cropping were greater than following continuous cotton. Yields of both potato and cotton in rotation were equivalent to either crop in monocropping. Yields of both crops were lower following double-cropping when nematicides were not used.

Damage Function and Economic Threshold for Belonolaimus longicaudatus on Potato.

Belonolaimus longicaudatus has long been recognized as a pathogen of potato (Solanum tuberosum). However, a damage function relating expected yield of potato to population densities of B. longicaudatus at planting has not been derived, and the economic threshold for nematicide application is unknown. The objectives of this study were to derive the damage function of B. longicaudatus on potato and to calculate the economic threshold population density. The damage function data for B. longicaudatus on potato were obtained from an ongoing field study to evaluate cropping systems and nematode management practices. Soil samples were collected from experimental field plots, and nematodes were extracted from a 130-cm(3) subsample with a centrifugal-flotation method. A damage function was derived by linear regression of potato yield on nematode population density at planting. Based on this derived damage function and published potato prices, the economic threshold for nematicide application was calculated at 2 to 3 B. longicaudatus/130 cm(3) of soil, which was near the detection threshold based on methodology used in this study.

Niche Distribution of Paratrichodorus minor and Belonolaimus longicaudatus Following Fumigation on Potato and Cabbage.

An experiment was conducted to determine population changes and niche variation in the soil at two depths (0 to 20 cm and 20 to 40 cm) of Paratrichodorus minor and Belonolaimus longicaudatus populations following fumigation. Eight plots each of potato (Solanum tuberosum) and cabbage (Brassica oleracea var. capitata), fumigated with 1, 3-dichloropropene or nonfumigated, were established. Eight plots of sorghum-sudangrass hybrid (Sorghum bicolor x S. arundinaceum var. sudanense) were also used to monitor depth distribution (0 to 20 cm and 20 to 40 cm) of B. longicaudatus and P. minor following each cabbage/potato season. Soil samples were taken 0 to 20 cm and 20 to 40 cm deep during the potato/cabbage, and sorghum-sudangrass growing seasons. During the 1993-94 and 1994-95 potato/cabbage seasons, P. minor was found at highest numbers at 20 to 40 cm, whereas numbers of B. longicaudatus were highest at 0 to 20 cm. During the 1994 and 1995 sorghum-sudangrass growing seasons, B. longicaudatus numbers were highest at 0 to 20 cm. Paratrichodorus minor numbers were highest at 0 to 20 cm and at 20 to 40 cm deep in the 1994 and 1995 sorghum-sudangrass growing seasons, respectively. Reduction by soil fumigation of B. longicaudatus at 0 to 20 cm deep did not affect depth distribution or cause P. minor populations to increase in potato or cabbage plots. Paratrichodorus minor numbers increased at 20 to 40 cm deep in the 1994-95 cabbage season after soil fumigation.

Temperature-Dependent Development of Pasteuria penetrans in Meloidogyne arenaria.

Pasteuria penetrans is a promising biological control agent of plant-parasitic nematodes. This study was conducted to determine effects of temperature on the bacterium's development in Meloidogyne arenaria. Developmental stages of P. penetrans were viewed with a compound microscope and verified with scanning electron microscopy within each nematode at 100 accumulated degree-day intervals by tracking accumulated degree-days at three temperatures (21, 28, and 35 degrees C). Five predominant developmental stages of P. penetrans were identified with light microscopy: endospore germination, vegetative growth, differentiation, sporulation, and maturation. Mature endospores were detected at 28, 35, and >90 calendar days at 35, 28, and 21 degrees C, respectively. The number of accumulated degree-days required for P. penetrans to reach a specific developmental stage was different for each temperature. Differences were observed in the development of P. penetrans at 21, 28, and 35 degrees C based on regression values fitted for data from 100 to 600 accumulated degree-days. A linear response was observed between 100 to 600 accumulated degree-days; however, after 600 accumulated degree-days the rate of development of P. penetrans leveled off at 21 and 28 degrees C, whereas at 35 degrees C the rate decreased. Results suggest that accumulated degree-days may be useful only in predicting early-developmental stages of P. penetrans.

Effects of soil fumigants and aldicarb on corky ringspot disease and trichodorid nematodes in potato.

In 1982 and 1983 the soil fumigants ethylene dibromide (EDB), EDB + chloropicrin, and 1,3-dichloropropene (1,3-D) applied with one or three chisels per row were evaluated singly and in combination with aldicarb on potato, Solanum tuberosum cvs. Atlantic and Sebago, for control of trichodorid nematodes and potato corky ringspot disease (CRS). In 1982 dosages per chisel for EDB, EDB + chloropicrin, and 1,3-D were 16.8, 23.9, and 56.1 liters/ha, respectively. EDB was applied at 12.6 liters per chisel per ha in 1983. Aldicarb was applied at 3.4 kg a.i./ha in-the-row. Differences (P

Effects of Soil Fumigants and Aldicarb on Bacterial Wilt and Root-knot Nematodes in Potato.

Preplant soil applications of oxamyl to shade grown tobacco in Globodera tabacum-infested field soil increased green leaf yields over untreated plots by 10.7 and 21.0% for 2.2 and 6.7 kg a.i. oxamyl/ha, respectively. Green leaf yield was negatively correlated (r = -0.60, P = 0.04) with initial G. tabacum density, which ranged from 33 to 154 second-stage juveniles (J2)/cm(3) soil. Numbers of G. tabacum J2 and developing juveniles and adults (J3-adults) per gram root were fewer in plants from oxamyl-treated plots than in plants from untreated plots. Numbers of J2 in roots 4, 6, and 8 weeks after transplanting were reduced by 80, 89, and 4%, respectively, and numbers of J3-adults were reduced by 96, 89, and 21%, respectively, in high-rate oxamyl plots, compared with untreated plots. Globodera tabacum reproduction, as measured by the ratio of final to initial soil densities, was less in oxamyl-treated plots than in untreated plots.

Effects of soil fumigants and aldicarb on nematodes, tuber quality, and yield in potato.

Efficacy of the fumigants ethylene dibromide (EDB), EDB + chloropicrin, and 1,3-dichloropropene (1,3-D) applied with one or three chisels per row, singly or in combination with aldicarb, was evaluated in 1982 and 1983 on potato (Solanum tuberosum) cultivars Atlantic and Sebago for control of several nematodes, including Belonolaimus longicaudatus, Meloidogyne incognita, and trichodorids. Generally, nematode populations were lowest following application of fumigants with three chisels per row, following EDB or EDB + chloropicrin, and when fumigants were applied in combination with aldicarb. These treatment combinations also resulted in highest yields in 1983. Cosmetic appearance of tubers was improved (P

Control of Nematodes and Soil-borne Diseases in Florida Potatoes with Aldicarb and 1,3-D.

Yields of U.S. Size A potato tubers were increased by 1,3-dichloropropene (1,3-D) (56 liters/ha) and 1,3-D (56 liters/ha) + aldicarb (3.4 kg/ha) in 1982 and 1983 and by aldicarb (3.4 kg/ha) in 1982. Treatments that included aldicarb provided the best control of corky ringspot disease, whereas those including 1,3-D were more effective against bacterial wilt. The most effective nematode control (nematodes included Meloidogyne incognita, Belonolaimus longicaudatus, trichodorids, Criconemella ornata, Tylenchorhynchus claytoni, and Helicotylenchus sp.) was provided by the combination of 1,3-D + aldicarb.

Measurement of lactate extraction ratio by centrifugal analyzer to assess myocardial ischemia.

The measurement of blood lactate to determine myocardial lactate extraction ratio requires a high degree of within-run precision, since small changes between arterial and coronary sinus lactate may occur. These changes in man may take place at lactate levels in the normal range, 5-18 mg/dl (0.56-2.00 mmol/l). The authors have developed a method for blood lactate determination utilizing commercially available reagents in a centrifugal analyzer (Centrifichem). Within-run precision in the low normal range, 5.4 mg/dl (0.60 mmol/l), showed a coefficient of variation of 7%. Precision extends to 50 mg/dl (5.55 mmol/l), and agreement with blood lactate values obtained with the Dupont ACA is good.