Stem Size Research Articles

Cementless femoral stems with lower canal fill ratio have similar mid-term to long-term outcomes to those with adequate fill ratio in Dorr type C femurs.

Lower canal fill ratio was reported to correlate with aseptic loosening in many studies. However, the most widely used standard of fill ratio seemed inapplicable to Dorr type C femurs. We aimed to adapt the method of measuring the fill ratio in Dorr type C femurs and compare the outcomes among patients with different fill ratios. Twenty patients with Corail stems implanted in their Dorr type C femurs received spectrum CT to evaluate the whole-stem's fill ratio. Pearson Correlation Coefficient was calculated to assess the correlation between the fill ratio in X-ray film and spectrum CT. Then 87 THAs were involved in this study, divided into the fill ratio ≤ 80% group and the fill ratio > 80% group. Clinical and radiological outcomes were evaluated with a mean follow-up of 8.2years. Fill ratio at 2cm below the lesser trochanter in anterior-posterior X-ray film correlated with the whole-stem's fill ratio (r = 0.50, P = 0.02). Survival rate of stem, function scores, and radiological outcomes between the two groups showed no significant difference. In the fill ratio > 80% group, intraoperative fracture was significantly higher (19% VS 5%, P < 0.05). Patients with lower fill ratios at 2cm below the lesser trochanter did not have poorer functional scores or more subsidence, but had a lower intraoperative fracture rate. The revision rates of the two groups presented no significant difference, but this result need to be confirmed in larger cohort in the future. In Dorr type C femurs, risk of fracture and the special morphology of the femur should be noted, and high fill ratio is not the most decisive factor for stem size selecting.

Processing and Extraction of Seasonal Tree Physiological Parameters from Stem Radius Time Series

Radial stem size changes, measured with automated dendrometers at intra-daily resolution, offer great potential to link environmental conditions with tree physiology at the seasonal scale. Such measurements need to be time-aligned, cleaned of outliers and shifts, gap-filled and analysed for reversible (water-related) and irreversible (growth-related) fractions to obtain physiologically meaningful data. Therefore, comprehensive tools are needed for reproducible data processing and analytics of dendrometer data. Here we present a transparent method, compiled in the R package treenetproc, to turn raw dendrometer data into clean, physiologically interpretable information, i.e., stem growth, tree water deficit, growth phenological phases, mean daily shrinkage and their respective timings. The removal of errors is facilitated by additional functions and supported with graphical visualizations. To ensure reproducible data handling, the processing parameters and induced changes to the raw data are documented in the output and, thus, are a step towards a standardized processing of automatically measured stem radius time series. We discuss examples, such as the seasonality of growth or the dependence of growth on atmospheric and soil drought. The presented growth and water-related physiological variables at high temporal resolution offer novel physiological insights into the seasonally varying responses of trees to changing environmental conditions.

Agronomic Character of Ratoon Rice: Stem Cutting Sizes and Seprint Liquid Organic Fertilizer

Abstract This study aimed to identify the optimum rice stem cutting size combined with the application of Seprint liquid organic fertilizer (SLOF) to promote the growth and yield of ratoon rice. This research was conducted in a greenhouse at the Faculty of Agriculture, University of Muhammadiyah Sumatera Utara, North Sumatra Province, Indonesia, from January to August 2018. The experiment was set up as a completely randomized design factorial with four replications. The first factor consisted of the cutting sizes of the rice stem (R1 = 5 cm, R2 = 10 cm, and R3 = 15 cm) and the second factor involved the SLOF dosage (S1 = 5 mL L −1 , S2 = 10 mL L −1 , and S3 = 15 mL L −1 ). The parameters were analyzed using analysis of variance (ANOVA), and the means were determined by Duncan’s multiple range test (DMRT). The results showed that the R2 treatment significantly increased the ratoon rice height at 10 to 30 days after cutting (DAC), the number of tillers at 40 to 60 DAC, the number of productive tillers, and the yield per hectare. The S2 and S3 applications at significantly increased the yield per hill and ratoon rice height at 20 DAC. The R2S1 and R2S2 combination treatments significantly increased the number of filled grains per panicle and the ratoon rice height at 10 DAC. Cutting the stems at 10 cm combined with various dosages of SLOF resulted in greater growth and yield of ratoon rice for achieving an adequate food supply.

CORR Insights®: The External Obturator Footprint Is a Usable, Accurate, and Reliable Landmark for Stem Depth in Direct Anterior THA.

CORR Insights®: The External Obturator Footprint Is a Usable, Accurate, and Reliable Landmark for Stem Depth in Direct Anterior THA.

Behaviour of quality indicators in banana cultivation, in El Oro province, Ecuador

Banana cultivation is recognized worldwide as a very energetic food line that has high volumes of annual production. The investigative results presented in the present investigation complement a group of studies developed in the province of El Oro, Ecuador. In order to assess the statistical behavior of quality indicators that affect banana yield. Three treatments were used (chemical and organic with respect to the control) in 6 banana plots during December / 2018-June / 2019. The study is descriptive and correlational. The indicators used were stem size, number of hands, number of fingers, plant height, pseudostem circumference and bunch weight at harvest time. Statistical and inferential methods were used, highlighting the correlation and regression analysis. The best results were observed in the treatment with organic fertilizer, which justifies the benefits of agroecology. The evaluated indicators generally coincide with the referenced studies. It was identified that the type of treatment does not influence the average height of the plants. It was possible to find a regression model with a good fit that allows estimating the circumference of the pseudostem according to the behavior of the plant height.

The Accuracy and Ability of Preoperative Templating to Restore Femoral Offset in Calcar-Guided Short-Stem Total Hip Prosthesis through Direct Anterior Approach

AbstractThe aim of this study was to assess the applicability and ability of preoperative templating to restore femoral offset and hip length with a calcar-guided short-stem implant design in total hip arthroplasty through the direct anterior approach. Preoperative measurements were performed of femoral offset, hip length, and stem size and compared with the perioperative placed prosthesis in 100 patients undergoing primary total hip replacement through direct anterior approach. Additionally, the pre- and postoperative femoral offset and hip length were compared to evaluate the ability to restore the offset and hip length with this kind of femoral short stem. With an acceptance of 1 size difference pre- and postoperatively, a 94% accuracy of predicting the size of the calcar-guided short stem was achieved with templating. Femoral offset was within means of 5 mm in 82.2% of the patients. Postoperative hip length was within 6 mm in 90% of the patients compared with the preoperative length.The use of preoperative templating for total hip arthroplasty with calcar-guided short-stem implants was proven to be a useful tool to predict the definite implanted size of the femoral prosthesis. Our results show that this new stem design does not significantly differ from previous reported outcomes with other stem designs and is competent to restore the femoral offset and hip length within clinical acceptable range. Level of evidence Level 3 retrospective case study.

Effect of Willow extract, Bistep and their combination on some quality parameters of lettuce (Lactuca sativa L.)

The research described in this paper was conducted at the University of Debrecen, Farm and Regional Research Institute in its Botanical and Exhibition Garden, Hungary. The aim was to investigate the influence of plant biostimulants on the morphological parameters of three lettuce varieties (May King, Kobak and Great Lakes). Willow bark extract and Bistep were used through irrigation and spray onto the plant leaves with the amount of 5% Willow and 0,5% Bistep. Vegetative parameters like head structure (1….10), head weight (g head-1), head closing (1….10), number of leaves, head diameter (cm), internal stem size (cm) and root weight (g head-1) were measured in 2019 and 2020. According to our results, vegetative parameters are significantly affected by plant varieties and treatments. In the experiment of 2019, important vegetative parameters were influenced by the Willow extract, while in the season of 2020 the most influenced parameters were under the impact of Bistep biostimulants followed by Willow+Bistep. However, the most favourable vegetative growth was recorded in the Kobak variety in the season of 2019 followed by May King and Great Lakes varieties in the season of 2020. On the other hand, the interaction effect of plant varieties and plant biostimulants on the vegetative parameters were varied from seasons. For example, for the season 2019, significantly the highest vegetative value was recorded for the interaction of May King variety treated with Willow extract, whereas in 2020, significantly the most influenced vegetative parameters were under the influence of the interaction of Bistep and May King variety followed by the interaction of Willow+Bistep and Kobak variety.

Including tree spatial extension in the evaluation of neighborhood competition effects in Bornean rain forest.

Classical tree neighborhood models use size variables acting at point distances. In a new approach here, trees were spatially extended as a function of their crown sizes, represented impressionistically as points within crown areas. Extension was accompanied by plasticity in the form of crown removal or relocation under the overlap of taller trees. Root systems were supposedly extended in a similar manner. For the 38 most abundant species in the focal size class (10–<100 cm stem girth) in two 4‐ha plots at Danum (Sabah), for periods P1 (1986–1996) and P2 (1996–2007), stem growth rate and tree survival were individually regressed against stem size, and neighborhood conspecific (CON) and heterospecific (HET) basal areas within incremented steps in radius. Model parameters were critically assessed, and statistical robustness in the modeling was set by randomization testing. Classical and extended models differed importantly in their outcomes. Crown extension weakened the relationship of CON effect on growth versus plot species’ abundance, showing that models without plasticity overestimated negative density dependence. A significant negative trend of difference in CON effects on growth (P2−P1) versus CON or HET effect on survival in P1 was strongest with crown extension. Model outcomes did not then support an explanation of CON and HET effects being due to (asymmetric) competition for light alone. An alternative hypothesis is that changes in CON effects on small trees, largely incurred by a drought phase (relaxing light limitation) in P2, and following the more shaded (suppressing) conditions in P1, were likely due to species‐specific (symmetric) root competition and mycorrhizal processes. The very high variation in neighborhood composition and abundances led to a strong “neighborhood stochasticity” and hence to largely idiosyncratic species’ responses. A need to much better understand the roles of rooting structure and processes at the individual tree level was highlighted.

Role OF Structural Indices and Other Spatial Measures in the Improvement Of Crown Variables Prediction For Lannea fructicosa

Theoretically, the stem of the tree must be strong enough to withstand the forces that act on it. These forces include the weight of the crown and the drag exerted on it by the wind. This mean that for a well-established root system, there should be some kind of balance between crown and stem sizes, otherwise the stem be break. The sizes, shapes and relative locations of crowns both determine and respond to the shading and constriction effects that characterize aboveground interactions between trees. Due to this kind of balance, tree crown parameters have been used as predictor variables in diameter and height growth equations. Although the correlation between tree variables and crown dimensions has well documented in the literature, other stand composition and conditions such as competition, elevation and aspect are believed to be among the unexplained forces that exert strong influences on the accuracy of the allometric models used for that relationship. This study attempted to quantify the effect of structural indices and other spatial measures to improve the prediction of crown radius and crown length for trees in natural woodlands. Field data were recorded for Lannea fruticosa tree species that naturally grown in Elgarri forest reserve in Blue Nile State, Sudan. The data was used to test the performance of estimating crown dimensions on the basis of allometric relationships with tree diameter and height. A total of thirteen spatial and non-spatial indices were incorporated into modified crown dimension models. Coefficient of multiple determination (R2) and relative bias were used to test the performance of these indices in improving the accuracy of estimates. According to the results all predictions of crown length and radius were found to be better after the incorporation of the spatial and non-spatial, with positive R2 gain and acceptable negative bias values for crown radius and positive ones for crown length. For all cases, the spatial indices were found to be better than the non-spatial ones.

Is analog preoperative planning still applicable?-comparison of accuracy of analog and computer preoperative planning methods in total hip arthroplasty.

BackgroundPreoperative planning is an integral part of total hip arthroplasty and has a significant impact on surgical technique and clinical outcome. The variety of types and sizes of endoprosthesis components makes the procedure more demanding and generates a need for accurate preoperative planning. The objective of this study was to analyze an analog method of preoperative planning of primary total hip arthroplasty based on templates overlaying on preoperative radiograms and compare its accuracy for predicting the size, both the stem and cup, with computer planning methods.MethodsA retrospective cohort study based on 360 X-ray images of hip joints in 348 patients qualified for total hip arthroplasty between 2018 and 2019. The study group consisted of 136 men and 212 women, with an average age of 65 years (56 to 85 years). Material included both cementless and cemented endoprostheses.ResultsIn the analyzed material, the accuracy of cup planning using the analog method was 85% (P<0.001) and 77% (P<0.001) in the planning of stem size. However, using the computer method, planning accuracy was 82% (P<0.001) for the cup and 72% (P<0.001) for the stem.ConclusionsBoth methods of preoperative planning remain effective. The analog method of preoperative planning is simple, precise, and repeatable in choosing the type and size of endoprosthesis components with an accuracy of 85% and 77% for the cup and stem respectively. The accuracy of planning depends on the type of endoprosthesis and in the case of the cemented endoprosthesis, it is lower than in cementless.

The Survival Rate and Starch Histochemical Assay of Various Stem Cutting Conditions of Mentega 2 Cassava Genotype at Initial Growth Stage

Background: This study aimed to evaluate the growth ability of cassava mini stem cuttings with different node number and a variety of stem cutting shapes and their correlation with starch content in the stems at initial growth stages. Methods. In this study, the viability of cassava stem cuttings was identified in two type experiments i.e. mini-stem cuttings consisting 1 and 2 nodes and shape variation of single node mini-stem cutting. Parameters observed were shoots emergence period, number of sprouting cuttings, shoots number of individual stem cuttings, shoots height and number of leaves. In addition, starch histochemical test was also carried out on stems of young shoots and initial stem cuttings using Lugol’s solution. Results. Both cassava stem cuttings consisting of 1 and 2 buds indicated the same survival rate of 100%. 1 bud stem cuttings with different shapes showed different survival rate, i.e. 60-80% for semicircular and fully circular cuttings and 30-40% for box shape cuttings. The difference in survival rate with different stem size is probably related to the availability of the amount of starch to support shoots growth. Observations at week 3 after planting generally showed that the stem cuttings with 2 buds were higher than those of stem with 1 bud. Conclusion: There were differences in the scores on the starch content test qualitatively with Lugol staining, in various parts of the plant originating from 1 bud and 2 bud cuttings which may indicate a breakdown of starch during shoot development.

Site carrying capacity of Norway spruce and Scots pine stands has increased in Germany and northern Europe

The maximum size-density relationship describes site carrying capacity, i.e., the maximum number of trees of a given size that can be stocked per unit area (self-thinning line). We analysed whether the self-thinning lines of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) have remained unchanged over time in South Germany, Norway and Finland, i.e., over a wide climatic gradient from Central Europe up to the Arctic circle. The analyses are based on long-term growth and yield experiments measured on individual tree basis over several decades, the oldest experiments established during the early 20th century. The stochastic frontier analysis was used to analyse changes in the species-specific self-thinning lines. The results show that the self-thinning lines have shifted upwards over time in all the regions. Thus, currently stands sustain higher stand densities than in the past. The increase of the maximum density for a given average stem size was more pronounced for pine than for spruce, but similar in all studied geographical regions. In addition, increasing site index was associated with increasing site carrying capacity for spruce and pine in all regions. The results imply that environmental changes have altered site properties in similar fashion across the whole study region. In practical forestry, increased site carrying capacity will reduce mortality and loss of growing stock.

Bed‐Load Transport in Vegetated Flows: Phenomena, Parametrization, and Prediction

AbstractThis study presents an experimental study on bed‐load transport in the presence of emergent vegetation, which is simulated using uniformly sized circular cylinders arranged in a homogeneous distribution. The spatial variability of bed‐load fluxes in vegetated flows is first examined. Then a model is proposed for evaluating the bed‐load transport rate based on the scour holes that form around the vegetation stems. The influences of spatial variability and intensified turbulence on sediment transport are finally considered by relating the dimensionless transport rate and flow intensity to the stem size and vegetation density. The derived formula for predicting the bed‐load transport rate in vegetated flows is applicable for weak to moderate transport conditions.

Definition and validation of a system for classifying the undersized Corail femoral stem in total hip arthroplasty.

The uncemented total hip arthroplasty relies on a secure initial fixation of the femoral stem to achieve osseointegration. Undersizing of the femoral implant compromises this. Surgeons routinely review postoperative radiographs to assess appropriate sizing, but existing methods of assessment lack standardisation. We present a system of accurately and reliably classifying radiological undersizing, which will help us better understand the factors that might have led to undersizing. To describe and evaluate a classification system for assessing radiological undersizing of the uncemented stem in hip arthroplasty. We conducted a retrospective review of 1,337 consecutive hip arthroplasties using the Corail stem. Two independent investigators reviewed post-operative radiographs and classified them as either appropriately sized or undersized. Undersized stems were sub-categorised into four subtypes: uniformly undersized, varus undersized, valgus undersized or 'cocktail-glass' undersized. Inter- and intra-observer agreement was determined. The accuracy of our classification system was validated by comparison with digital re-templating. We further assessed patient demographics and stem size in relation to sizing. 1 in 5 cases (19.75%) were deemed radiologically undersized. The commonest subtypes of undersizing were uniformly (47%) and varus (39%) undersized. When assessing sizing and subtype categorisation, inter-observer agreement was 89-92% and intra-observer agreement 86%. Classification decisions showed 92% and 97% accuracy for uniformly undersizing and varus undersizing respectively when validated against digital re-templating. Age, gender and smaller stem size were significantly associated with radiological undersizing. The Corail KLA model (125° neck) was found to have a higher incidence of stems undersized in varus. This study describes and validates a classification system for the analysis of radiological undersizing.

Quantitative Assessment of Vegetation Layers in Tropical Evergreen Forests of Arunachal Pradesh, Eastern Himalaya, India

The present study deals with first-hand information on quantitative assessments of different vegetation layers (viz. trees, saplings, seedlings, shrubs and herbs) collected from 57 permanent plots (size 400 m2), established for long-term monitoring of biodiversity and study of functional aspects in Namdapha National Park (NPP), Arunachal Pradesh, Eastern Himalaya, India during 2017. We grouped all the plots into six clusters as study sites. A total of 60 taxa of trees, 67 shrubs and 81 herbs were recorded within 57 plots during the study. The average species richness per site for trees was 20.83 ± 1.62, saplings 16.0 ± 1.15, seedlings 15.83 ± 1.35, shrubs 23.83 ± 1.58 and herbs 32.67 ± 0.92. Total stem density varied from 117.5 to and 181 ha –1 (152.58 ± 10.04 ha –1 ) for trees (circumference m31.5 cm), 881 to 3000 ha –1 (1652.17 ± 317.61 ha –1 ) for shrubs and from 76750 to 98545 ha –1 (92032.17 ± 3246.60 ha –1 ) for herbs. Tree regeneration status at all the six study sites was ‘good’ (i.e. density of seedlings > saplings > trees). The distribution of tree stems (circumference m31.5 cm) into different size classes showed highest relative density in the lowest stem size class (10–20 cm diameter) which also indicates good tree regeneration in the study area. Dipterocarpus retusus Blume was the most dominant tree species in the core zone area of NNP with ‘good’ regeneration status.

Interspecific variation in post‐disturbance growth responses of a savanna tree community and its implications for escaping the fire trap

AbstractVegetation states in savannas are highly sensitive to tree growth rates, which determine whether individual trees can “escape” periodic disturbances. Resprouting trees have lopsided shoot:root ratios and are often multi‐stemmed, and these variables can modify post‐disturbance growth rates and therefore the probability of escape. To date, few studies have systematically examined the implications of interspecific variation in these factors for escape. We conducted a two‐year field experiment across 16 tree species in a South African lowveld savanna to quantify growth metrics following topkill. We examined the dependence of growth on pre‐disturbance stem size and the relationship between growth rate and the tendency of trees to produce a few large vs. many small resprouts following disturbance. We found that resprout growth was strongly influenced by pre‐disturbance size, but the strength of this relationship did not vary across species. In contrast, our results showed that fast‐growing species tended to allocate resources toward a few dominant stems, while slow‐growing species allocated new biomass towards many smaller stems. Tree species that produced a few large stems also tended to produce individual stems that were tall and thin, further suggesting that the “few large vs. many small” axis is linked to intrinsic species attributes. These findings have implications for understanding how interspecific variation in savanna tree communities may influence their ability to escape disturbance traps.

Impact of Stem Size on Turbulence and Sediment Resuspension Under Unidirectional Flow

AbstractLaboratory experiments examined the impact of model vegetation on turbulence and resuspension. The turbulent kinetic energy increased with increasing velocity and increasing solid volume fraction, but did not depend on stem diameter. The vegetation‐generated turbulence dominated the total turbulence inside canopies. For the same sediment size, the critical turbulent kinetic energy at which resuspension was initiated was the same for both vegetated and bare beds, which resulted in a critical velocity that decreased with increasing solid volume fraction. Both the critical turbulence and critical velocity for resuspension had no dependence on stem diameter. However, for denser canopies and/or a canopy of smaller stem size, a greater energy slope is required to initiate resuspension. This study provides a way to predict the onset of resuspension in regions with vegetation, an important threshold for sediment transport and landscape evolution.

Three decades of post-logging tree community recovery in naturally regenerating and actively restored dipterocarp forest in Borneo

Selective logging has affected large areas of tropical forests and there is increasing interest in how to manage selectively logged forests to enhance recovery. However, the impacts of logging and active restoration, by liberation cutting and enrichment planting, on tree community composition are poorly understood compared to trajectories of biomass recovery. Here, we assess the long-term impacts of selective logging and active restoration for biomass recovery on tree species diversity, community composition, and forest structure. We censused all stems ≥2 cm diameter at breast height (DBH) on 46 permanent plots in unlogged, primary forest in the Danum Valley Conservation Area (DVCA; 12 plots, totalling 0.6 ha) and in sites logged 23–35 years prior to the census in the Ulu Segama Forest Reserve adjacent to DVCA (34 plots, totalling 1.7 ha) in Sabah, Malaysian Borneo. Active restoration treatments, including enrichment planting and climber cutting, were implemented on 17 of the logged forest plots 12–24 years prior to the census. Total plot-level basal area and pole (5–10 cm DBH) stem density were lower in logged than unlogged forests, however no difference was found in stem density amongst saplings (2–5 cm DBH) or established trees (≥10 cm DBH). Neither basal area, nor plot-level stem density varied with time since logging at any size class, although sapling and pole stem densities were lower in actively restored than naturally regenerating logged forest. Sapling species diversity was lower in logged than unlogged forest, however there were no other significant effects of logging on tree species richness or diversity indices. Tree species composition, however, differed between logged and unlogged forests across all stem size classes (PERMANOVA), reflected by 23 significant indicator species that were only present in unlogged forest. PERMANOVA tests revealed no evidence that overall species composition changed with time since logging or with active restoration treatments at any size class. However, when naturally regenerating and actively restored communities were compared, two indicator species were identified in naturally regenerating forest and three in actively restored forests. Together our results suggest that selective logging has a lasting effect on tree community composition regardless of active restoration treatments and, even when species richness and diversity are stable, species composition remains distinct from unlogged forest for more than two decades post-harvest. Active restoration efforts should be targeted, monitored, and refined to try to ensure positive outcomes for multiple metrics of forest recovery.

Value of 3D preoperative planning for primary total hip arthroplasty based on artificial intelligence technology

BackgroundAccurate preoperative planning is an important step for accurate reconstruction in total hip arthroplasty (THA). Presently, preoperative planning is completed using either a two-dimensional (2D) template or three-dimensional (3D) mimics software. With the development of artificial intelligence (AI) technology, AI HIP, a planning software based on AI technology, can quickly and automatically identify acetabular and femur morphology, and automatically match the optimal prosthesis size. However, the accuracy and feasibility of its clinical application still needs to be further verified. The purposes of this study were to investigate the accuracy and time efficiency of AI HIP in preoperative planning for primary THA, compared with 3D mimics software and 2D digital template, and further analyze the factors that influence the accuracy of AI HIP.MethodsA prospective study was conducted on 53 consecutive patients (59 hips) undergoing primary THA with cementless prostheses in our department. All preoperative planning was completed using AI HIP as well as 3D mimics and 2D digital template. The predicted component size and the actual implantation results were compared to determine the accuracy. The templating time was compared to determine the efficiency. Furthermore, the potential factors influencing the accuracy of AI HIP were analyzed including sex, body mass index (BMI), and hip dysplasia.ResultsThe accuracy of predicting the size of acetabular cup and femoral stem was 74.58% and 71.19%, respectively, for AI HIP; 71.19% (P = 0.743) and 76.27% (P = 0.468), respectively, for 3D mimics; and 40.68% (P < 0.001) and 49.15% (P = 0.021), respectively, for 2D digital templating. The templating time using AI HIP was 3.91 ± 0.64 min, which was equivalent to 2D digital templates (2.96 ± 0.48 min, P < 0.001), but shorter than 3D mimics (32.07 ± 2.41 min, P < 0.001). Acetabular dysplasia (P = 0.021), rather than sex and BMI, was an influential factor in the accuracy of AI HIP templating. Compared to patients with developmental dysplasia of the hip (DDH), the accuracy of acetabular cup in the non-DDH group was better (P = 0.021), but the difference in the accuracy of the femoral stem between the two groups was statistically insignificant (P = 0.062).ConclusionAI HIP showed excellent reliability for component size in THA. Acetabular dysplasia may affect the accuracy of AI HIP templating.

Trees grow modulated by the ecological memory of their past growth. Consequences for monitoring, modelling, and silvicultural treatment

The growth of forest trees under given environmental conditions is assumed to depend mainly on their age, stem and crown size, and competitive position in the stand. The current stem and crown size are commonly recognized as adequate proxy markers for the tree's ecological memory of the past. In contrast, tree ring structure, crown whorl morphology, or other biographical patterns are rarely used for predicting growth. Here, we asked how the latter affect tree growth.Our main hypothesis was that the growth in the longer past significantly co-determines the present growth. To test this hypothesis we derived metrics which quantify the social position, course of growth, and annual variation of trees in their past. We further selected variables for quantifying the trees' present stem and crown size and competitive status. Finally, we selected the approximately 200-years-old thinning experiment in European beech (Fagus sylvatica L.) Fabrikschleichach 15 in South Germany as our study object because it provided all required information.To examine the dependency of the current growth on the present growing conditions and the past tree development more closely, we applied linear mixed models. They revealed that (i) trees with similar age, size, crown and competitive status at present grew better if they were subdominant in the past. (ii) Ceteris paribus, slow starting trees with progressive growth trajectories were associated with higher growth than quick starting trees with degressive growth trajectories. (iii) Trees with lower interannual variations of growth in the past had significantly higher growth rates at present than trees with higher interannual variations of growth in the past. (iv) Including information about the trees' past reduced the RSME of the diameter growth model by 17–27% and increased the R2 by 15–30%. Thus, the diameter growth model could achieve R2 values of 0.76–0.79. (v) The contribution of past information for estimating present growth was higher in periods without thinning.We suggest that in the analysed European beech stands, even at parity of stem diameter or crown size, different courses of growth created different internal stem structures and crown morphologies. Such past structural and morphological formations may affect the tree's light interception and hydraulic conduction. These differences in structure may cause specific differences in the present tree functioning and growth. Of course these findings based on only one long-term experiment should not yet be generalized. However, the revealed relationship between the past and present growth deserves further investigations. We discuss the relevance of the ecological memory embedded in the past growth and in the tree ring pattern. We stress the consequences of the ecological memory for the monitoring, inventory, and modelling of tree growth and its implications for the development of silvicultural prescriptions.