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1.
Nature ; 577(7790): 381-385, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31853068

RESUMEN

Homo erectus is the founding early hominin species of Island Southeast Asia, and reached Java (Indonesia) more than 1.5 million years ago1,2. Twelve H. erectus calvaria (skull caps) and two tibiae (lower leg bones) were discovered from a bone bed located about 20 m above the Solo River at Ngandong (Central Java) between 1931 and 19333,4, and are of the youngest, most-advanced form of H. erectus5-8. Despite the importance of the Ngandong fossils, the relationship between the fossils, terrace fill and ages have been heavily debated9-14. Here, to resolve the age of the Ngandong evidence, we use Bayesian modelling of 52 radiometric age estimates to establish-to our knowledge-the first robust chronology at regional, valley and local scales. We used uranium-series dating of speleothems to constrain regional landscape evolution; luminescence, 40argon/39argon (40Ar/39Ar) and uranium-series dating to constrain the sequence of terrace evolution; and applied uranium-series and uranium series-electron-spin resonance (US-ESR) dating to non-human fossils to directly date our re-excavation of Ngandong5,15. We show that at least by 500 thousand years ago (ka) the Solo River was diverted into the Kendeng Hills, and that it formed the Solo terrace sequence between 316 and 31 ka and the Ngandong terrace between about 140 and 92 ka. Non-human fossils recovered during the re-excavation of Ngandong date to between 109 and 106 ka (uranium-series minimum)16 and 134 and 118 ka (US-ESR), with modelled ages of 117 to 108 thousand years (kyr) for the H. erectus bone bed, which accumulated during flood conditions3,17. These results negate the extreme ages that have been proposed for the site and solidify Ngandong as the last known occurrence of this long-lived species.


Asunto(s)
Hominidae , Animales , Evolución Biológica , Fósiles , Indonesia , Huesos de la Pierna , Cráneo , Factores de Tiempo
2.
Nature ; 534(7606): 245-8, 2016 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-27279221

RESUMEN

The evolutionary origin of Homo floresiensis, a diminutive hominin species previously known only by skeletal remains from Liang Bua in western Flores, Indonesia, has been intensively debated. It is a matter of controversy whether this primitive form, dated to the Late Pleistocene, evolved from early Asian Homo erectus and represents a unique and striking case of evolutionary reversal in hominin body and brain size within an insular environment. The alternative hypothesis is that H. floresiensis derived from an older, smaller-brained member of our genus, such as Homo habilis, or perhaps even late Australopithecus, signalling a hitherto undocumented dispersal of hominins from Africa into eastern Asia by two million years ago (2 Ma). Here we describe hominin fossils excavated in 2014 from an early Middle Pleistocene site (Mata Menge) in the So'a Basin of central Flores. These specimens comprise a mandible fragment and six isolated teeth belonging to at least three small-jawed and small-toothed individuals. Dating to ~0.7 Ma, these fossils now constitute the oldest hominin remains from Flores. The Mata Menge mandible and teeth are similar in dimensions and morphological characteristics to those of H. floresiensis from Liang Bua. The exception is the mandibular first molar, which retains a more primitive condition. Notably, the Mata Menge mandible and molar are even smaller in size than those of the two existing H. floresiensis individuals from Liang Bua. The Mata Menge fossils are derived compared with Australopithecus and H. habilis, and so tend to support the view that H. floresiensis is a dwarfed descendent of early Asian H. erectus. Our findings suggest that hominins on Flores had acquired extremely small body size and other morphological traits specific to H. floresiensis at an unexpectedly early time.


Asunto(s)
Fósiles , Hominidae/anatomía & histología , Hominidae/clasificación , Animales , Tamaño Corporal , Indonesia , Mandíbula/anatomía & histología , Tamaño de los Órganos , Datación Radiométrica , Diente/anatomía & histología
3.
Nature ; 529(7585): 208-11, 2016 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-26762458

RESUMEN

Sulawesi is the largest and oldest island within Wallacea, a vast zone of oceanic islands separating continental Asia from the Pleistocene landmass of Australia and Papua (Sahul). By one million years ago an unknown hominin lineage had colonized Flores immediately to the south, and by about 50 thousand years ago, modern humans (Homo sapiens) had crossed to Sahul. On the basis of position, oceanic currents and biogeographical context, Sulawesi probably played a pivotal part in these dispersals. Uranium-series dating of speleothem deposits associated with rock art in the limestone karst region of Maros in southwest Sulawesi has revealed that humans were living on the island at least 40 thousand years ago (ref. 5). Here we report new excavations at Talepu in the Walanae Basin northeast of Maros, where in situ stone artefacts associated with fossil remains of megafauna (Bubalus sp., Stegodon and Celebochoerus) have been recovered from stratified deposits that accumulated from before 200 thousand years ago until about 100 thousand years ago. Our findings suggest that Sulawesi, like Flores, was host to a long-established population of archaic hominins, the ancestral origins and taxonomic status of which remain elusive.


Asunto(s)
Fósiles , Hominidae , Animales , Historia Antigua , Migración Humana/historia , Humanos , Indonesia , Comportamiento del Uso de la Herramienta
4.
Nature ; 534(7606): 249-53, 2016 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-27279222

RESUMEN

Recent excavations at the early Middle Pleistocene site of Mata Menge in the So'a Basin of central Flores, Indonesia, have yielded hominin fossils attributed to a population ancestral to Late Pleistocene Homo floresiensis. Here we describe the age and context of the Mata Menge hominin specimens and associated archaeological findings. The fluvial sandstone layer from which the in situ fossils were excavated in 2014 was deposited in a small valley stream around 700 thousand years ago, as indicated by (40)Ar/(39)Ar and fission track dates on stratigraphically bracketing volcanic ash and pyroclastic density current deposits, in combination with coupled uranium-series and electron spin resonance dating of fossil teeth. Palaeoenvironmental data indicate a relatively dry climate in the So'a Basin during the early Middle Pleistocene, while various lines of evidence suggest the hominins inhabited a savannah-like open grassland habitat with a wetland component. The hominin fossils occur alongside the remains of an insular fauna and a simple stone technology that is markedly similar to that associated with Late Pleistocene H. floresiensis.


Asunto(s)
Arqueología , Ambiente , Fósiles , Hominidae , Datación Radiométrica , Animales , Argón , Clima , Espectroscopía de Resonancia por Spin del Electrón , Pradera , Historia Antigua , Indonesia , Radioisótopos , Comportamiento del Uso de la Herramienta , Diente/química , Erupciones Volcánicas/historia , Humedales
5.
Nature ; 532(7599): 366-9, 2016 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-27027286

RESUMEN

Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question.


Asunto(s)
Arqueología , Fósiles , Hominidae , Datación Radiométrica , Silicatos de Aluminio , Animales , Australia , Calibración , Cuevas , Sedimentos Geológicos/análisis , Vidrio , Humanos , Indonesia , Compuestos de Potasio , Cuarzo , Factores de Tiempo , Incertidumbre
6.
J Arthroplasty ; 35(10): 3031-3037, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32600812

RESUMEN

BACKGROUND: The goal was to determine if the addition of a metaphyseal stem extension limits micromotion of a cementless tibial component during cyclic loading in primary total knee arthroplasty. The hypothesis tested was that the use of a 50-mm stem extension on a cementless tibial component would limit motion compared with an identical cementless component without a stem extension. METHODS: The study used 3 variations of a tibial component from the same total knee arthroplasty system. Group 1 consisted of a cementless tibial component without a stem extension. Group 2 used the same cementless component as group 1, but with the addition of a short 50-mm stem. Group 3 consisted of a cemented tibial component without a stem extension to serve as a "control" (gold standard). The tibial specimens were implanted into a synthetic bone model and tested using a physiological medial-lateral 60/40 load distribution for 5000 cycles. RESULTS: The results demonstrated a significant decrease in motion at the anterior region of the cementless stem extension (group 2) components compared with the cementless with no stem extension (group 1). The cementless with stem extension (group 2) demonstrated similar results at all cycles to the cemented (group 3) components at the anterior region. CONCLUSION: The addition of a short metaphyseal stem (50mm) to a keel plus 4-peg tibial component design provides a significant reduction in micromotion during cyclic loading of a cementless tibial baseplate in a synthetic foam bone model, similar to a cemented implant.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Prótesis de la Rodilla , Cementos para Huesos , Humanos , Movimiento (Física) , Diseño de Prótesis , Tibia/cirugía
7.
J Shoulder Elbow Surg ; 26(7): 1246-1252, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28159474

RESUMEN

BACKGROUND: Mini-stem humeral component (MSHC) use during total shoulder arthroplasty (TSA) provides bone preservation and ease of revision. MSHCs rely solely on proximal metaphyseal fixation; some early reports have demonstrated an unacceptably high rate of early loosening. To our knowledge, no study analyzing the effect of proximal porous coating on MSHCs has been performed. METHODS: We performed a retrospective review of consecutive patients who underwent anatomic TSA using coated or uncoated MSHCs with minimum 2-year follow-up. Postoperative radiographs were assessed for risk of or frank stem loosening, subsidence, and presence of radiolucencies. Range of motion, outcome scores (visual analog scale pain, American Shoulder and Elbow Surgeons, and Single Assessment Numeric Evaluation), and any complications were noted. RESULTS: We analyzed 68 shoulders with a mean follow-up of 27.3 months (range, 24-50 months). Of these, 34 had proximal coating and 34 were uncoated. In the coated group, no stems loosened, 1 (2.9%) subsided, and 7 (20.6%) developed radiolucencies. In the uncoated group, 1 stem (2.9%) became aseptically loose (requiring revision after 26 months), 7 (20.6%) were judged at risk of loosening (2 because of subsidence), and 15 (44.1%) developed radiolucencies. There was also an increased risk of proximal medial humeral radiolucencies among uncoated MSHCs. There were no significant differences in final range of motion or outcome scores. CONCLUSION: MSHC use is appropriate for TSA, achieving desired pain relief and functional improvement. Overall, component loosening appears uncommon at early follow-up; however, uncoated stems appear to be at greater risk of loosening and developing radiolucencies. Selecting an MSHC with proximal porous coating may decrease the risk of implant-related complications.


Asunto(s)
Artroplastía de Reemplazo de Hombro/instrumentación , Artroplastía de Reemplazo de Hombro/métodos , Húmero/cirugía , Complicaciones Posoperatorias/prevención & control , Falla de Prótesis , Prótesis de Hombro , Adulto , Anciano , Anciano de 80 o más Años , Artroplastía de Reemplazo de Hombro/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Osteotomía , Dimensión del Dolor , Complicaciones Posoperatorias/etiología , Periodo Posoperatorio , Falla de Prótesis/etiología , Radiografía , Rango del Movimiento Articular , Estudios Retrospectivos , Factores de Riesgo , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/fisiopatología , Dolor de Hombro/etiología , Propiedades de Superficie
8.
Nature ; 464(7289): 748-52, 2010 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-20237472

RESUMEN

Previous excavations at Mata Menge and Boa Lesa in the Soa Basin of Flores, Indonesia, recovered stone artefacts in association with fossilized remains of the large-bodied Stegodon florensis florensis. Zircon fission-track ages from these sites indicated that hominins had colonized the island by 0.88 +/- 0.07 million years (Myr) ago. Here we describe the contents, context and age of Wolo Sege, a recently discovered archaeological site in the Soa Basin that has in situ stone artefacts and that lies stratigraphically below Mata Menge and immediately above the basement breccias of the basin. We show using (40)Ar/(39)Ar dating that an ignimbrite overlying the artefact layers at Wolo Sege was erupted 1.02 +/- 0.02 Myr ago, providing a new minimum age for hominins on Flores. This predates the disappearance from the Soa Basin of 'pygmy' Stegodon sondaari and Geochelone spp. (giant tortoise), as evident at the nearby site of Tangi Talo, which has been dated to 0.90 +/- 0.07 Myr ago. It now seems that this extirpation or possible extinction event and the associated faunal turnover were the result of natural processes rather than the arrival of hominins. It also appears that the volcanic and fluvio-lacustrine deposits infilling the Soa Basin may not be old enough to register the initial arrival of hominins on the island.


Asunto(s)
Geografía , Hominidae/fisiología , Animales , Arqueología , Extinción Biológica , Historia Antigua , Indonesia , Paleontología , Tecnología/historia , Factores de Tiempo
9.
J Hand Surg Am ; 40(4): 711-5, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25701490

RESUMEN

PURPOSE: To assess the results of olecranon fractures with an intra-articular sagittal plane fracture managed by orthogonal fixation constructs. METHODS: A retrospective chart review was performed and 14 proximal ulna fractures with intra-articular comminution resulting in separate medial and lateral fragments were identified. All fractures were classified according to the Schatzker, Mayo, and AO classification systems. Postoperative functional assessment, Disabilities of the Arm, Shoulder, and Hand (DASH) score, time to union, and complications were recorded. RESULTS: Eleven patients were treated with both dorsal and lateral plates. Three patients were managed with a single dorsal plate and cerclage wires. All fractures healed. Mean length of follow-up was 15 months (range, 4-72 mo). Mean range of motion at final follow-up was a flexion-extension arc of 24° to 129° with 89° and 79° of pronation and supination, respectively. The most common complication was symptomatic hardware, leading to removal of hardware in 5 of 14 (36%) patients. Average postoperative Disabilities of the Arm, Shoulder, and Hand score was 7. Two patients developed heterotopic ossification and 1 patient required a local pedicled flap for soft-tissue coverage. CONCLUSIONS: Identification of this subset of fractures is critical to successful management. A supplemental lateral plate or cerclage wires can successfully manage these difficult fractures and achieve good outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.


Asunto(s)
Olécranon/lesiones , Fracturas del Cúbito/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Placas Óseas , Hilos Ortopédicos , Femenino , Fracturas Conminutas/diagnóstico por imagen , Fracturas Conminutas/cirugía , Humanos , Fracturas Intraarticulares/diagnóstico por imagen , Fracturas Intraarticulares/cirugía , Masculino , Persona de Mediana Edad , Radiografía , Fracturas del Cúbito/diagnóstico por imagen , Adulto Joven
10.
J Shoulder Elbow Surg ; 24(7): 1156-64, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25799922

RESUMEN

BACKGROUND: The in vivo effects of metal hypersensitivity remain a topic of much debate. At the core of this debate is the possible, although still hotly contested, link between metal hypersensitivity and poorly functioning or failing implants. There are multiple studies on this topic in the hip and knee arthroplasty literature, but the applicability of this experience to shoulder arthroplasty remains unclear. Although how often metal hypersensitivity affects shoulder arthroplasty patients remains uncertain, a multitude of case reports have implicated metallic implants as a source of local and systemic allergic reactions. We recommend a cautious approach to patients with a history of metal hypersensitivity, including a careful evaluation of suspected metal hypersensitivities in all patients undergoing shoulder arthroplasty. If available, we recommend a metallic implant with low to no nickel content in patients with metal hypersensitivity. Given the large and increasing, number of total shoulder arthroplasty procedures and the high percentage of the population having a known or suspected metal hypersensitivity, this review is intended to guide and educate the shoulder surgeon in the evaluation and treatment of this patient population and to point out the areas where evidence-based recommendations are lacking.


Asunto(s)
Artroplastia de Reemplazo/efectos adversos , Hipersensibilidad/etiología , Prótesis Articulares/efectos adversos , Metales/efectos adversos , Articulación del Hombro/cirugía , Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Humanos , Hipersensibilidad/diagnóstico , Tamizaje Masivo
11.
J Hum Evol ; 64(2): 109-29, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23290261

RESUMEN

The carpals from the Homo floresiensis type specimen (LB1) lack features that compose the shared, derived complex of the radial side of the wrist in Neandertals and modern humans. This paper comprises a description and three-dimensional morphometric analysis of new carpals from at least one other individual at Liang Bua attributed to H. floresiensis: a right capitate and two hamates. The new capitate is smaller than that of LB1 but is nearly identical in morphology. As with capitates from extant apes, species of Australopithecus, and LB1, the newly described capitate displays a deeply-excavated nonarticular area along its radial aspect, a scaphoid facet that extends into a J-hook articulation on the neck, and a more radially-oriented second metacarpal facet; it also lacks an enlarged palmarly-positioned trapezoid facet. Because there is no accommodation for the derived, palmarly blocky trapezoid that characterizes Homo sapiens and Neandertals, this individual most likely had a plesiomorphically wedge-shaped trapezoid (like LB1). Morphometric analyses confirm the close similarity of the new capitate and that of LB1, and are consistent with previous findings of an overall primitive articular geometry. In general, hamate morphology is more conserved across hominins, and the H. floresiensis specimens fall at the far edge of the range of variation for H. sapiens in a number of metrics. However, the hamate of H. floresiensis is exceptionally small and exhibits a relatively long, stout hamulus lacking the oval-shaped cross-section characteristic of human and Neandertal hamuli (variably present in australopiths). Documentation of a second individual with primitive carpal anatomy from Liang Bua, along with further analysis of trapezoid scaling relative to the capitate in LB1, refutes claims that the wrist of the type specimen represents a modern human with pathology. In total, the carpal anatomy of H. floresiensis supports the hypothesis that the lineage leading to the evolution of this species originated prior to the cladogenetic event that gave rise to modern humans and Neandertals.


Asunto(s)
Hueso Grande del Carpo/anatomía & histología , Hueso Ganchoso/anatomía & histología , Hominidae/anatomía & histología , Animales , Biometría , Femenino , Fósiles , Hominidae/clasificación , Humanos , Indonesia , Masculino , Filogenia
12.
Nature ; 441(7093): 624-8, 2006 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-16738657

RESUMEN

In the Soa Basin of central Flores, eastern Indonesia, stratified archaeological sites, including Mata Menge, Boa Lesa and Kobatuwa (Fig. 1), contain stone artefacts associated with the fossilized remains of Stegodon florensis, Komodo dragon, rat and various other taxa. These sites have been dated to 840-700 kyr bp (thousand years before present). The authenticity of the Soa Basin artefacts and their provenance have been demonstrated by previous work, but to quell lingering doubts, here we describe the context, attributes and production modes of 507 artefacts excavated at Mata Menge. We also note specific similarities, and apparent technological continuity, between the Mata Menge stone artefacts and those excavated from Late Pleistocene levels at Liang Bua cave, 50 km to the west. The latter artefacts, dated to between 95-74 and 12 kyr ago, are associated with the remains of a dwarfed descendent of S. florensis, Komodo dragon, rat and a small-bodied hominin species, Homo floresiensis, which had a brain size of about 400 cubic centimetres. The Mata Menge evidence negates claims that stone artefacts associated with H. floresiensis are so complex that they must have been made by modern humans (Homo sapiens).


Asunto(s)
Evolución Biológica , Hominidae/fisiología , Tecnología/historia , Animales , Arqueología , Fósiles , Historia Antigua , Hominidae/anatomía & histología , Hominidae/clasificación , Humanos , Indonesia , Filogenia , Ratas , Factores de Tiempo
13.
J Hum Evol ; 61(6): 644-82, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22036083

RESUMEN

This paper describes in detail the external morphology of LB1/1, the nearly complete and only known cranium of Homo floresiensis. Comparisons were made with a large sample of early groups of the genus Homo to assess primitive, derived, and unique craniofacial traits of LB1 and discuss its evolution. Principal cranial shape differences between H. floresiensis and Homo sapiens are also explored metrically. The LB1 specimen exhibits a marked reductive trend in its facial skeleton, which is comparable to the H. sapiens condition and is probably associated with reduced masticatory stresses. However, LB1 is craniometrically different from H. sapiens showing an extremely small overall cranial size, and the combination of a primitive low and anteriorly narrow vault shape, a relatively prognathic face, a rounded oval foramen that is greatly separated anteriorly from the carotid canal/jugular foramen, and a unique, tall orbital shape. Whereas the neurocranium of LB1 is as small as that of some Homo habilis specimens, it exhibits laterally expanded parietals, a weak suprameatal crest, a moderately flexed occipital, a marked facial reduction, and many other derived features that characterize post-habilis Homo. Other craniofacial characteristics of LB1 include, for example, a relatively narrow frontal squama with flattened right and left sides, a marked frontal keel, posteriorly divergent temporal lines, a posteriorly flexed anteromedial corner of the mandibular fossa, a bulbous lateral end of the supraorbital torus, and a forward protruding maxillary body with a distinct infraorbital sulcus. LB1 is most similar to early Javanese Homo erectus from Sangiran and Trinil in these and other aspects. We conclude that the craniofacial morphology of LB1 is consistent with the hypothesis that H. floresiensis evolved from early Javanese H. erectus with dramatic island dwarfism. However, further field discoveries of early hominin skeletal remains from Flores and detailed analyses of the finds are needed to understand the evolutionary history of this endemic hominin species.


Asunto(s)
Evolución Biológica , Cara/anatomía & histología , Fósiles , Hominidae/anatomía & histología , Cráneo/anatomía & histología , Animales , Cefalometría/métodos , Femenino , Hominidae/clasificación , Indonesia , Análisis de Componente Principal , Tomografía Computarizada por Rayos X
14.
PLoS One ; 15(2): e0226628, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32023252

RESUMEN

The Kimberley region of Western Australia is one of the largest and most diverse rock art provenances in the world, with a complex stylistic sequence spanning at least 16 ka, culminating in the modern art-making of the Wunumbal people. The Gunu Site Complex, in the remote Mitchell River region of the northwest Kimberley, is one of many local expressions of the Kimberley rock art sequence. Here we report excavations at two sites in this complex: Gunu Rock, a sand sheet adjacent to rock art panels; and Gunu Cave, a floor deposit within an extensive rockshelter. Excavations at Gunu Rock provide evidence for two phases of occupation, the first from 7-8 to 2.7 ka, and the second from 1064 cal BP. Excavations at Gunu Rock provide evidence for occupation from the end of the second phase to the recent past. Stone for tools in the early phase were procured from a variety of sources, but quartz crystal reduction dominated the second occupation phase. Small quartz crystals were reduced by freehand percussion to provide small flake tools and blanks for manufacturing small points called nguni by the Wunambal people today. Quartz crystals were prominent in historic ritual practices associated with the Wanjina belief system. Complex methods of making bifacially-thinned and pressure flaked quartzite projectile points emerged after 2.7 ka. Ochre pigments were common in both occupation phases, but evidence for occupation contemporaneous with the putative age of the oldest rock art styles was not discovered in the excavations. Our results show that developing a complete understanding of rock art production and local occupation patterns requires paired excavations inside and outside of the rockshelters that dominate the Kimberley.


Asunto(s)
Arqueología , Arte , Cuevas , Geografía , Imagenología Tridimensional , Australia Occidental
15.
Am J Phys Anthropol ; 140(1): 52-63, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19294744

RESUMEN

The type specimen (LB1) of Homo floresiensis has been hypothesized to be a pathological human afflicted with Laron Syndrome (LS), a type of primary growth hormone insensitivity (Hershkovitz et al.: Am J Phys Anthropol 134 [2007] 198-208). Comparing measurements, photographs and three-dimensional, computed-tomography reconstructions of LB1 with data and diagnoses from the literature on LS, we critically evaluate numerous skull and postcranial traits that Hershkovitz et al. identified as being shared by LB1 and patients with LS. The statements regarding most of these traits are new to the clinical literature and lack quantitative support. LB1 and patients with LS differ markedly in the size and shape of the cranium; thickness and pneumatization of cranial bones; morphology of the face, mandible, teeth, and chin; form of the shoulder, wrist, and pelvis; and general body proportions including relative foot size. Claims that patients with LS are similar to LB1 in displaying protracted scapulae, short clavicles, low degrees of humeral torsion, flaring ilia, and curved tibiae are not supported by data or corroborating images. Some points of similarity (e.g., femoral neck-shaft angle, femoral bicondylar angle, and estimated stature) can be found in other hominins, and cannot be considered diagnostic. From our review and analysis, we conclude that LB1 did not suffer from LS.


Asunto(s)
Tamaño Corporal , Fósiles , Hominidae , Síndrome de Laron/patología , Cráneo/patología , Animales , Femenino , Humanos , Imagenología Tridimensional , Síndrome de Laron/diagnóstico por imagen , Masculino , Pelvis/diagnóstico por imagen , Pelvis/patología , Cráneo/diagnóstico por imagen , Tomografía Computarizada por Rayos X
16.
Injury ; 50(4): 978-982, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30929804

RESUMEN

INTRODUCTION: The incidence of periprosthetic fractures after total knee arthroplasty (TKA) is rising due to an increasing number of TKAs performed annually and the growing elderly population. Like periprosthetic fractures of the distal femur, periprosthetic tibia fractures are primarily treated with operative fixation; however, there is limited scientific literature that has reported outcomes of periprosthetic tibia fractures treated with modern plating techniques. To our knowledge, this is the largest series of non-intraoperative periprosthetic tibia fractures treated with open reduction internal fixation (ORIF) ever reported. METHODS: Retrospective chart review of 4557 operatively treated tibia fractures with ORIF over a 16-year period at two Level 1 Trauma Centers. RESULTS: 38 patients with an average follow-up of 15.3 months (range 3-24) were identified. 11 (28.9%) fractures were in the proximal tibia (four with extension into the plateau (Felix 1A) and seven adjacent to the tibial stem (Felix 2A)), six (15.8%) in the midshaft/diaphysis (Felix 3A), and 21 (55.3%) in the distal 1/3rd (metaphysis, Felix 3A). 76.3% (29/38) of fractures united by 6 months following the index procedure, leaving 9 nonunions. The overall re-operation rate was 31.6% (12/38). There were no significant differences in rates of union (p = 1.00), reoperation (p = 0.66), superficial infection (p = 0.66), or deep infection (p = 0.31) in patients treated with single versus dual plating. CONCLUSION: Periprosthetic tibia fractures are difficult to treat and have a high risk of nonunion and reoperation even with modern plating techniques. Most patients can be treated to union with operative fixation and do not require revision arthroplasty, if the components are stable initially. We recommend dual plating for fractures in the proximal third, and either single plating or nailing for fractures in the middle and distal thirds depending on bone quality, implant positioning, and fracture morphology.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Fijación Intramedular de Fracturas , Curación de Fractura/fisiología , Fracturas Periprotésicas/cirugía , Reoperación/estadística & datos numéricos , Fracturas de la Tibia/cirugía , Artroplastia de Reemplazo de Rodilla/efectos adversos , Artroplastia de Reemplazo de Rodilla/estadística & datos numéricos , Estudios de Seguimiento , Fijación Intramedular de Fracturas/efectos adversos , Fijación Intramedular de Fracturas/estadística & datos numéricos , Fracturas Mal Unidas , Humanos , Fracturas Periprotésicas/fisiopatología , Estudios Retrospectivos , Fracturas de la Tibia/fisiopatología , Resultado del Tratamiento
17.
J Orthop Trauma ; 33(11): 547-552, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31403558

RESUMEN

OBJECTIVES: To determine the optimal fixation method [intramedullary nail (IMN) vs. plate fixation (PF)] for treating critical bone defects with the induced membrane technique, also known as the Masquelet technique. DESIGN: Retrospective cohort study. SETTING: Four Level 1 Academic Trauma Centers. PATIENTS/PARTICIPANTS: All patients with critical bone defects treated with the induced membrane technique, or Masquelet technique, between January 1, 2005, and January 31, 2018. INTERVENTION: Operative treatment with a temporary cement spacer to induce membrane formation, followed by spacer removal and bone grafting at 6-8 weeks. MAIN OUTCOME MEASUREMENTS: Time to union, number/reason for reoperations, time to full weight-bearing, and any complications. RESULTS: One hundred twenty-one patients (56 tibias and 65 femurs) were treated with a mean follow-up of 22 months (range 12-148 months). IMN was used in 57 patients and plates in 64 patients. Multiple grafting procedures were required in 10.5% (6/57) of those with IMN and 28.1% (18/64) of those with PF (P = 0.015). Reoperation for all causes occurred in 17.5% (10/57) with IMN and 46.9% (30/64) with PF (P = 0.001). Average time to weight-bearing occurred at 2.44 versus 4.63 months for those treated with IMN and plates, respectively (P = 0.002). The multivariable adjusted analysis showed that PF is 6.4 times more likely to require multiple grafting procedures (P = 0.017) and 7.7 times more likely to require reoperation (P = 0.003) for all causes compared with IMN." CONCLUSIONS: This is the largest study to date evaluating the Masquelet technique for critical size defects in the femur and tibia. Our results indicate that patients treated with IMN had faster union, fewer grafting procedures, and fewer reoperations for all causes than those treated with plates, with differences more evident in the femur. The authors believe this is a result of both the development of an intramedullary canal and circumferential stress on the graft with early weight-bearing when using an IMN, as opposed to a certain degree of stress shielding and delayed weight-bearing when using PF. We, therefore, recommend the use of an IMN whenever possible as the preferred method of fixation for tibial and femoral defects when using the Masquelet technique. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Clavos Ortopédicos , Placas Óseas , Fracturas del Fémur/cirugía , Fijación Intramedular de Fracturas/instrumentación , Fracturas de la Tibia/cirugía , Adulto , Estudios de Cohortes , Femenino , Fracturas del Fémur/diagnóstico por imagen , Fijación Intramedular de Fracturas/métodos , Curación de Fractura/fisiología , Humanos , Puntaje de Gravedad del Traumatismo , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Recuperación de la Función , Estudios Retrospectivos , Medición de Riesgo , Fracturas de la Tibia/diagnóstico por imagen , Estados Unidos , Adulto Joven
18.
J Orthop Trauma ; 33(8): 392-396, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31116138

RESUMEN

OBJECTIVES: To determine whether immediate weightbearing after intramedullary (IM) fixation of extra-articular distal tibial fractures (OTA/AO 43-A) results in a change in alignment before healing. DESIGN: Retrospective review. SETTING: Level 1 trauma center. INTERVENTION: IM nailing of distal tibial fractures. PATIENTS/PARTICIPANTS: Fifty-three patients with 54 fractures, all of whom could bear weight as tolerated postoperatively. Eighteen fractures were OTA/AO 43-A1, 20 OTA/AO 43-A2, and 16 OTA/AO 43-A3; 20 fractures were open. MAIN OUTCOME MEASUREMENTS: Change in fracture alignment or loss of position. RESULTS: Average change from initial angulation at final follow-up was 0.52 ± 1.49 degrees of valgus and 0.48 ± 3.14 degrees of extension. Final alignment was excellent in 14, acceptable in 28, and poor in 12; 2 fractures went from acceptable initial alignment to poor final alignment; and 2 fractures went from excellent to acceptable alignment. Seven fractures had an improvement in alignment over time. Two fractures required free-flap coverage and 4 required staged grafting because of bone loss. Ten fractures had an unplanned return to the operating room (5 for infected nonunion requiring implant exchange, 3 for infection requiring debridement without implant revision, and 2 for aseptic nonunion). No patient had revision for implant failure. CONCLUSIONS: Immediate weightbearing after IM fixation of extra-articular distal tibial fractures (OTA/AO 43-A) led to minimal change in alignment and seems to be safe for most patients. Complications were consistent with those reported in previous non-weightbearing cohorts. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Clavos Ortopédicos , Fijación Intramedular de Fracturas , Fracturas de la Tibia/cirugía , Soporte de Peso , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Curación de Fractura , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
19.
Patient Saf Surg ; 12: 31, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30410578

RESUMEN

INTRODUCTION: Recent advances have led to the design of a new cephalomedullary nail, which aims to decrease the risk of failures in patients with intertrochanteric hip fractures by allowing for insertion of two interdigitating screws into the head segment. The goal of this study is to evaluate the safety and efficacy of this two-screw cephalomedullary nailing system. PATIENTS/PARTICIPANTS: Patients 18 years of age and older who underwent intramedullary nailing of their intertrochanteric femoral fracture using the InterTAN nailing system (Smith and Nephew, Memphis, TN) from 2012 to 2016 were included in this retrospective study which was performed at two urban certified level-1 trauma centers and one urban certified level-3 trauma center. The study data was collected through a retrospective chart review and review of the existing radiographic studies. Primary outcome measure was mechanical hardware failure and screw cutout. Secondary outcome measures included nonunion, malunion, medical and surgical complications. RESULTS: A total of 264 patients were included in this analysis. Two patients (0.75%) were found to have a screw cut out requiring revision surgery. Two other revision surgeries were performed for malrotation (n = 1) and malunion (n = 1). Other implant-related complications occurred in 19 cases (7.9%), which included broken distal screws (n = 9), distal screw loosening (n = 8), and loose lag screws (n = 2). There was a total of 10 (3.8%) surgical wound complications, including four deep and six superficial infections. DISCUSSION: This modified cephalomedullary nail is a reliable, safe, and effective implant for management of intertrochanteric hip fractures. Surgical treatment of patients with intertrochanteric hip fractures can be performed in a safe fashion using this implant.

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