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Concept: Pelvis

205

BACKGROUND: Pterosaurs have been known from the Cretaceous sediments of the Isle of Wight (southern England, United Kingdom) since 1870. We describe the three-dimensional pelvic girdle and associated vertebrae of a small near-adult pterodactyloid from the Atherfield Clay Formation (lower Aptian, Lower Cretaceous). Despite acknowledged variation in the pterosaur pelvis, previous studies have not adequately sampled or incorporated pelvic characters into phylogenetic analyses. METHODOLOGYPRINCIPAL FINDINGS: The new specimen represents the new taxon Vectidraco daisymorrisae gen. et sp. nov., diagnosed by the presence of a concavity posterodorsal to the acetabulum and the form of its postacetabular process on the ilium. Several characters suggest that Vectidraco belongs to Azhdarchoidea. We constructed a pelvis-only phylogenetic analysis to test whether the pterosaur pelvis carries a useful phylogenetic signal. Resolution in recovered trees was poor, but they approximately matched trees recovered from analyses of total evidence. We also added Vectidraco and our pelvic characters to an existing total-evidence matrix for pterosaurs. Both analyses recovered Vectidraco within Azhdarchoidea. CONCLUSIONSSIGNIFICANCE: The Lower Cretaceous strata of western Europe have yielded members of several pterosaur lineages, but Aptian pterosaurs from western Europe are rare. With a pelvis length of 40 mm, the new animal would have had a total length of c. 350 mm, and a wingspan of c. 750 mm. Barremian and Aptian pterodactyloids from western Europe show that small-bodied azhdarchoids lived alongside ornithocheirids and istiodactylids. This assemblage is similar in terms of which lineages are represented to the coeval beds of Liaoning, China; however, the number of species and specimens present at Liaoning is much higher. While the general phylogenetic composition of western European and Chinese communities appear to have been approximately similar, the differences may be due to different palaeoenvironmental and depositional settings. The western Europe pterodactyloid record may therefore be artificially low in diversity due to preservational factors.

Concepts: Europe, Pelvis, Acetabulum, Cretaceous, Pterosaur, Pterodactyloidea, Western Europe, Ilium

173

There are several well-described causes of a painful mass following total hip arthroplasty including polyethylene and metal wear debris, infection, expanding hematoma, dislocation, and synovial cysts. In addition to causing pain, these lesions, when large enough, may cause neurologic and vascular compromise. Rapid growth of the mass may clinically and radiographically resemble a sarcoma. Here, we report a case of a large painful hip mass which developed after total hip arthroplasty. The well-circumscribed mass was overlying and extending into the hip joint containing thousands of highly organized fibrin-containing “rice bodies”. To our knowledge, this is the first report of a large, highly organized (rice-body-containing) cyst complicating total hip arthroplasty.

Concepts: Causality, Hip replacement, Hip, Pelvis, Orthopedic surgery, Joint replacement, Synovial joint, Polyethylene

171

Late rupture of external iliac artery pseudo-aneurysm is an uncommon complication in patients who undergo extensive gynecologic radical surgeries. A 28-year-old woman with stage IB cervical cancer underwent pelvic lymphadenectomy and extrafascial trachelectomy. Two months after surgery, massive bleeding from ruptured pseudo-aneurysm of the external iliac artery occurred. Endovascular management with covered stent placement was feasible and safe to stop bleeding.

Concepts: Cervical cancer, Surgery, Radiation therapy, Stent, Pelvis, Hysterectomy, External iliac artery, Internal iliac artery

169

BACKGROUND: Prolonged physical impairments in range of movement, postural stability and walking speed are commonly reported following total hip replacement (THR). It is unclear from the current body of evidence what kind of exercises should be performed to maximize patient function and quality of life.Methods/designThis will be a single blind multi centre randomized control trial with two arms. Seventy subjects post primary total hip arthroplasty will be randomized into either an experimental group (n=35), or to a control group (n=35).. The experimental group will attend a functional exercise class twice weekly for a six week period from week 12 to week 18 post surgery. The functional exercise group will follow a circuit based functional exercise class supervised by a chartered Physiotherapist. The control group will receive usual care. The principal investigator (BM) will perform blinded outcome assessments on all patients using validated measures for pain, stiffness, and function using the Western Ontario and Mc Master Universities Osteoarthritis index (WOMAC). This is the primary outcome measurement tool. Secondary outcome measurements include Quality of life (SF-36), 6 min walk test, Visual Analogue Scale, and the Berg Balance score. The WOMAC score will be collated on day five post surgery and repeated at week twelve and week eighteen. All other measurements will be taken at week 12 and repeated at week eighteen. In addition a blinded radiologist will measure gluteus medius cross sectional area using real time ultrasound for all subjects at week 12 and at week 18 to determine if the functional exercise programme has any effect on muscle size. DISCUSSION: This randomised controlled trial will add to the body of evidence on the relationship between muscle size, functional ability, balance, quality of life and time post surgery in patients following total hip arthroplasty. The CONSORT guidelines will be followed to throughout. Ethical approval has been gained from the Ethics committee Health Services Executive Dublin North East.Trial registrationThis trial is registered with ClinicalTrials.gov (a service of the United States National Institutes of Health) identifier NCT01683201.

Concepts: Experimental design, Randomized controlled trial, Hip replacement, Hip, Pelvis, Orthopedic surgery, Joint replacement

168

In total hip arthroplasty, determining the impingement free range of motion requirement is a complex task. This is because in the native hip, motion is restricted by both impingement as well as soft tissue restraint. The aim of this study is to determine a range of motion benchmark which can identify motions which are at risk from impingement and those which are constrained due to soft tissue. Two experimental methodologies were used to determine motions which were limited by impingement and those motions which were limited by both impingement and soft tissue restraint. By comparing these two experimental results, motions which were limited by impingement were able to be separated from those motions which were limited by soft tissue restraint. The results show motions in extension as well as flexion combined with adduction are limited by soft tissue restraint. Motions in flexion, flexion combined with abduction and adduction are at risk from osseous impingement. Consequently, these motions represent where the maximum likely damage will occur in femoroacetabular impingement or at most risk of prosthetic impingement in total hip arthroplasty.

Concepts: Hip replacement, Hip, Pelvis, Orthopedic surgery, Extension, Abduction, Adduction, Gracilis muscle

163

A variety of patient-related outcome questionnaires have been used for the assessment of results of total hip replacement. Generic core scales (SF-12, SF-36) and disease-specific scales like: Harris Hip Score, Western Ontario and McMaster University Osteoarthritis Index, Hip dysfunction and Osteoarthritis Outcome Score, Oxford Hip Score, American Academy of Orthopedic Surgeons hip and knee Questionnaire, Lower Extremity Functional Scale are used most frequently. Even though all of them were assessed in terms of construct and content validity, reproducibility and sensitivity, there are still some problems related to bias when total hip replacement evaluation is performed in the presence of comorbidities, contralateral hip disease and ceiling effect influencing the final score. As a result, there is a need for development of a new PRO questionnaire in order to improve total hip replacement assessment, enable early detection of postoperative complications or to evaluate the results of surgery in both hips separately. It is crucial that such measuring device has to be deprived of the influence of irrelevant factors on the final score.

Concepts: Assessment, Psychometrics, Hip replacement, Hip, Pelvis, Orthopedic surgery, Joint replacement, John Charnley

159

Fishes have adapted a number of different behaviors to move out of the water, but none have been described as being able to walk on land with a tetrapod-like gait. Here we show that the blind cavefish Cryptotora thamicola walks and climbs waterfalls with a salamander-like diagonal-couplets lateral sequence gait and has evolved a robust pelvic girdle that shares morphological features associated with terrestrial vertebrates. In all other fishes, the pelvic bones are suspended in a muscular sling or loosely attached to the pectoral girdle anteriorly. In contrast, the pelvic girdle of Cryptotora is a large, broad puboischiadic plate that is joined to the iliac process of a hypertrophied sacral rib; fusion of these bones in tetrapods creates an acetabulum. The vertebral column in the sacral area has large anterior and posterior zygapophyses, transverse processes, and broad neural spines, all of which are associated with terrestrial organisms. The diagonal-couplet lateral sequence gait was accomplished by rotation of the pectoral and pelvic girdles creating a standing wave of the axial body. These findings are significant because they represent the first example of behavioural and morphological adaptation in an extant fish that converges on the tetrapodal walking behaviour and morphology.

Concepts: Vertebral column, Pelvis, Human anatomy, Acetabulum, Walking, Pubis, Sacrum, Ilium

155

The Lufeng Formation in Lufeng Basin of Yunnan Province, southwestern China preserves one of the richest terrestrial Lower Jurassic vertebrate faunas globally, especially for its basal sauropodomorphs, such as Lufengosaurus and Yunnanosaurus. Here we report a new taxon, Xingxiulong chengi gen. et sp. nov. represented by three partial skeletons with overlapping elements. Xingxiulong possesses a number of autapomorphies, such as transversely expanded plate-like summit on top of the neural spine of posterior dorsal vertebrae, four sacral vertebrae, robust scapula, and elongated pubic plate approximately 40% of the total length of the pubis. Phylogenetic analysis resolves Xingxiulong as a basal member of Sauropodiformes, and together with another two Lufeng basal sauropodiforms Jingshanosaurus and Yunnanosaurus, they represent the basalmost lineages of this clade, indicating its Asian origin. Although being relatively primitive, Xingxiulong displays some derived features normally occurred in advanced sauropodiforms including sauropods, such as a four sacral-sacrum, a robust scapula, and a pubis with elongated pubic plate. The discovery of Xingxiulong increases the diversity of basal sauropodomorphs from the Lufeng Formation and indicates a more complicated scenario in the early evolution of sauropodiforms.

Concepts: Phylogenetic nomenclature, Pelvis, Cladistics, Vertebra, Yunnan, Kunming, Dinosaur, Prosauropoda

154

A major challenge in understanding the origin of terrestrial vertebrates has been knowledge of the pelvis and hind appendage of their closest fish relatives. The pelvic girdle and appendage of tetrapods is dramatically larger and more robust than that of fish and contains a number of structures that provide greater musculoskeletal support for posture and locomotion. The discovery of pelvic material of the finned elpistostegalian, Tiktaalik roseae, bridges some of these differences. Multiple isolated pelves have been recovered, each of which has been prepared in three dimensions. Likewise, a complete pelvis and partial pelvic fin have been recovered in association with the type specimen. The pelves of Tiktaalik are paired and have broad iliac processes, flat and elongate pubes, and acetabulae that form a deep socket rimmed by a robust lip of bone. The pelvis is greatly enlarged relative to other finned tetrapodomorphs. Despite the enlargement and robusticity of the pelvis of Tiktaalik, it retains primitive features such as the lack of both an attachment for the sacral rib and an ischium. The pelvic fin of Tiktaalik (NUFV 108) is represented by fin rays and three endochondral elements: other elements are not preserved. The mosaic of primitive and derived features in Tiktaalik reveals that the enhancement of the pelvic appendage of tetrapods and, indeed, a trend toward hind limb-based propulsion have antecedents in the fins of their closest relatives.

Concepts: Fish, Pelvis, Sarcopterygii, Tetrapod, Sacrum, Coelacanth, Ischium, Fin

148

Intrauterine contraceptive device is the most common method of reversible contraception in women. The intrauterine contraceptive device can perforate the uterus and can also migrate into pelvic or abdominal organs. Perforation of the urinary bladder by an intrauterine contraceptive device is not common. In West Africa, intravesical migration of an intrauterine contraceptive device has been rarely reported. In this report, we present a case of an intrauterine contraceptive device migration into the urinary bladder of a 33 year old African woman at the Komfo Anokye Teaching Hospital, Kumasi, Ghana.

Concepts: Kidney, Birth control, Africa, Uterus, Intrauterine device, Urinary bladder, Pelvis, Peritoneum