Polyurethane Scaffold vs Fascia Lata Autograft for Hip Labral Reconstruction : Comparison of Femoroacetabular Biomechanics

The integrity of the acetabular labrum is critical in providing normal function and minimizing hip degeneration and is considered key for success in today's hip preservation algorithm. Many advances have been made in labral repair and reconstruction to restore the suction seal. To compare the biomechanical effects of segmental labral reconstruction between the synthetic polyurethane scaffold (PS) and fascia lata autograft (FLA). Our hypothesis was that reconstruction with a macroporous polyurethane implant and autograft reconstruction of fascia lata would normalize hip joint kinetics and restore the suction seal. Controlled laboratory study. Ten cadaveric hips from 5 fresh-frozen pelvises underwent biomechanical testing with a dynamic intra-articular pressure measurement system under 3 conditions: (1) intact labrum, (2) reconstruction with PS after a 3-cm segmental labrectomy, then (3) reconstruction with FLA. Contact area, contact pressure, and peak force were evaluated in 4 positions: 90º of flexion in neutral, 90º of flexion plus internal rotation, 90º of flexion plus external rotation, and 20º of extension. A labral seal test was performed for both reconstruction techniques. The relative change from the intact condition (value = 1) was determined for all conditions and positions. PS restored contact area to at least 96% of intact (≥0.96; range, 0.96-0.98) in all 4 positions, and FLA restored contact area to at least 97% (≥0.97; range, 0.97-1.19). Contact pressure was restored to ≥1.08 (range, 1.08-1.11) with the PS and ≥1.08 (range, 1.08-1.10) with the FLA technique. Peak force returned to ≥1.02 (range, 1.02-1.05) with PS and ≥1.02 (range, 1.02-1.07) with FLA. No significant differences were found between the reconstruction techniques in contact area in any position (P >.06), with the exception that FLA presented greater contact area in flexion plus internal rotation as compared with PS (P =.003). Suction seal was confirmed in 80% of PSs and 70% of FLAs (P = .62). Segmental hip labral reconstruction using PS and FLA reapproximated femoroacetabular contact biomechanics close to the intact state. These findings provide preclinical evidence supporting the use of a synthetic scaffold as an alternative to FLA and therefore avoiding donor site morbidity

Low-dose prophylaxis protocol for heterotopic ossification after hip preservation surgery in a sport participants cohort

Background: Heterotopic ossification (HO) is a well-known complication of arthroscopic and open surgical treatment of femoroacetabular impingement (FAI). Incidence of heterotopic ossification has been reported in the literature between 0% and 44% after hip arthroscopy and between 18.2% and 25% after anterior mini-open surgery. Currently, pharmacological prophylaxis with NSAIDs and selective COX-2 inhibitors are commonly used and their effectiveness is well documented in literature. Hypothesis: We hypothesized that the low-dose prophylaxis protocol with selective cox-2 inhibitors decreases the risk of heterotopic ossification in open or arthroscopic hip preservation surgery in athletes. Methods: This study is an analysis of prospectively gathered data on 98 sport participant patients who underwent arthroscopic or anterior mini-open treatment for FAI between April 2008 and April 2018. All the patients received postoperative oral prophylaxis with 60 mg etoricoxib once daily for two weeks. Post-operative X-rays were performed at 1, 3, and 12 months after surgery and reviewed by two orthopedic surgeons blinded to the type and side of surgery. HO were graded according to the Brooker classification. Descriptive statistics was used to analyze demographic data. Bivariate analysis was performed to analyze the association of HO with each of the following variables: type of surgery, physical activity, time of evolution of symptoms, age at surgery, and sex. Finally, a regression model analysis was performed to determine the presence of confounding effects between variables. Results: The study cohort was composed of 54 patients in the arthroscopic treatment group and 44 patients in the anterior mini-open group. HO was identified in 6 (13.6%) patients in the mini-open group. No HO was identified in the arthroscopic group. In the bivariate analysis, “type of surgery” was the only variable that showed a statistically significant association with HO (p = 0.007). Conclusion: Results of this study suggest that anterior mini-open treatment was characterized by a higher risk of HO development compared to hip arthroscopy for femoroacetabular impingement treatment regardless of pharmacological prophylaxis. The treatment regimen of 60 mg etoricoxib daily for two weeks was an effective prophylaxis for HO formation in sport participant patients compared with data available in the literature

Mass production of genetically modified Aedes aegypti for field releases in Brazil

New techniques and methods are being sought to try to win the battle against mosquitoes. Recent advances in molecular techniques have led to the development of new and innovative methods of mosquito control based around the Sterile Insect Technique (SIT)(1-3). A control method known as RIDL (Release of Insects carrying a Dominant Lethal)(4), is based around SIT, but uses genetic methods to remove the need for radiation-sterilization(5-8). A RIDL strain of Ae. aegypti was successfully tested in the field in Grand Cayman(9,10); further field use is planned or in progress in other countries around the world. Mass rearing of insects has been established in several insect species and to levels of billions a week. However, in mosquitoes, rearing has generally been performed on a much smaller scale, with most large scale rearing being performed in the 1970s and 80s. For a RIDL program it is desirable to release as few females as possible as they bite and transmit disease. In a mass rearing program there are several stages to produce the males to be released: egg production, rearing eggs until pupation, and then sorting males from females before release. These males are then used for a RIDL control program, released as either pupae or adults(11,12). To suppress a mosquito population using RIDL a large number of high quality male adults need to be reared(13,14). The following describes the methods for the mass rearing of OX513A, a RIDL strain of Ae. aegypti (8), for release and covers the techniques required for the production of eggs and mass rearing RIDL males for a control program.Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnologia (CNPq

Estudio de la cinética articular de cadera tras la reconstrucción del labrum acetabular mediante un implante macroporoso de poliuretano. Estudio biomecánico en un modelo cadavérico

El labrum acetabular juga un paper primordial en la cinètica articular del maluc. És per aquesta raó que la restauració de la funció labral és considerada clau per l'èxit de la cirurgia de preservació de maluc. L'objectiu de l'estudi és avaluar l'efecte de la reconstrucció d'una lesió del labrum acetabular, produïda per una labrectomia parcial anterosuperior, amb un implant artificial de poliuretà macroporós (IPM) i amb un empelt de fàscia lata (IFL). Material i Mètode. S'ha realitzat un estudi biomecànic cadavèric utilitzant 10 malucs de 5 pelvis fresques-congelades amb labrum acetabular intacte i sense osteoartritis. Amb un sistema de prova electromecànic intrarticular s'ha mesurat l'àrea de contacte (AC), la pressió de contacte (PC) i la tensió punta (TP) per a les següents condicions: 1) Labrum intacte; b) Labrectomia parcial anterosuperior; c) Reconstrucció amb IPM; d) Reconstrucció amb IFL. Els espècimens van ser analitzats per cada condició en: flexió de 90º, flexió de 90º més rotació interna, flexió de 90º més rotació externa, extensió de 20º. A més, en cada condició es va realitzar la prova de segellat labral. Es va dur a terme una anàlisi estadística normalitzant les mesures al labrum intacte, assignant-li el valor 1, per identificar les diferències de les mesures obtingudes en els paràmetres biomecànics entre les quatre condicions. Resultats. La labrectomia parcial va disminuir l'AC (0,82 ± 0,07), va augmentar la PC (1,28 ± 0,20) i la TP (1,27 ± 0,10) en tots els mesuraments en comparació al labrum intacte (p0,05), excepte en la rotació interna amb IFL (0,93 ± 0,03, p=0,037); encara que ambdues disminueixen la PC en comparació a la labrectomia parcial (p> 0,05), no aconsegueixen normalitzar la PC al labrum intacte tots els moviments del rang articular analitzat (p 0,05), excepte amb IFL en flexió (1 07 ± 0,04, p=0,002) i en la rotació externa (1,07 ± 0,07, p=0,008). Quan vam comparar l'AC, la PC i la TP entre la reconstrucció amb IPM i IFL no es van trobar diferències en cap de les posicions del rang articular entre les condicions (p>0,05). La prova de segellat labral es perd quan es realitza una labrectomia parcial i es restableix en un 80% dels casos quan es reconstrueix amb un IPM i en un 70% amb el IFL. Conclusions. En el present estudi biomecànic realitzat in vitro, observem que després d'haver realitzat una labrectomia parcial anterosuperior, la reconstrucció amb IPM i la reconstrucció amb IFL es restauren l'àrea de contacte, s'aconsegueix normalitzar les pressions de contacte i la tensió punta en comparació a una labrectomía parcial anterosuperior, sense observar diferències entre les dues tècniques de reconstrucció.El labrum acetabular tiene un rol primordial en la cinética articular de la cadera. Es por esta razón, que la restauración de la función labral es considerada clave para el éxito de la cirugía de preservación de cadera. El objetivo del estudio es evaluar el efecto de la reconstrucción de una lesión del labrum acetabular, producida por una labrectomía parcial anterosuperior, con un implante artificial de poliuretano macroporoso (IPM) y con un autoinjerto de fascia lata (AFL). Material y Método. Se ha realizado un estudio biomecánico cadavérico utilizando 10 caderas de 5 pelvis frescas-congeladas con labrum acetabular intacto y sin osteoartritis. Con un sistema de prueba electromecánico intraarticular se ha medido el área de contacto (AC), la presión de contacto (PC) y la tensión punta (TP) para las siguientes condiciones: 1) Labrum intacto; b) Labrectomía parcial anterosuperior; c) Reconstrucción con IPM; d) Reconstrucción con AFL. Los especímenes fueron analizados para cada condición en: flexión de 90º, flexión de 90º más rotación interna, flexión de 90º más rotación externa, extensión de 20º. Además, en cada condición se realizó la prueba de sellado labral. Se llevó a cabo un análisis estadístico normalizando las medidas al labrum intacto, asignándole el valor 1, para identificar las diferencias de las medidas obtenidas en los parámetros biomecánicos entre las cuatro condiciones. Resultados. La labrectomía parcial disminuyó el AC (0,82 ± 0,07), aumentó la PC (1,28±0,20) y la TP (1,27±0,10) en todas las mediciones en comparación al labrum intacto (p0,05), excepto en la rotación interna con AFL (0,93 ± 0,03, p=0,037); Aunque ambas disminuyen la PC en comparación a la labrectomía parcial (p>0,05), no logran normalizar la PC al labrum intacto en todos los movimientos del rango articular analizado (p0,05), excepto con AFL en flexión (1,07 ± 0,04, p=0,002) y en la rotación externa (1,07 ± 0,07, p=0,008). Al comparar el AC, la PC y la TP entre la reconstrucción con IPM e AFL no se encontraron diferencias en ninguna de las posiciones del rango articular entre las condiciones (p>0,05). La prueba de sellado labral se pierde cuando se realiza una labrectomía parcial y se restablece en un 80% de los casos cuando se reconstruye con un IPM y en un 70% con el AFL. Conclusiones. En el presente estudio biomecánico realizado in vitro, se obtiene que tras haber realizado una labrectomía parcial anterosuperior, la reconstrucción con IPM y la reconstrucción con AFL restauran el área de contacto, consiguen normalizar las presiones de contacto y la tensión punta en comparación con una labrectomía parcial anterosuperior, sin observar diferencias entre ambas técnicas de reconstrucción.The acetabular labrum plays a major role in hip joint kinetics. For this reason, restoration of labral function is considered key for the success of hip preservation surgery. The purpose of the study is to evaluate the effect of the reconstruction of an acetabular labrum injury, produced by an anterosuperior partial labrectomy, with an Artificial macroporous Polyurethane Implant (API) and with a Fascia Lata Autograft (FLA). Methods. A cadaveric biomechanical study was performed using 10 hips from 5 fresh-frozen pelvises with intact acetabular labrum and without osteoarthritis. Using an intra-articular electromechanical test system, the contact area (CA), the contact pressure (CP) and the peak force (PF) were measured for the following conditions: 1) Intact labrum; b) Anterosuperior partial labrectomy; c) Reconstruction with API; d) Reconstruction with FLA. The specimens were analyzed for each condition in: 90º flexion, 90º flexion plus internal rotation, 90º flexion plus external rotation, 20º extension. In addition, a labral seal test was performed in each condition. The statistical analysis was carried out to identify the differences in the measurements obtained in the biomechanical parameters between the four conditions by normalizing the measurements of the intact labrum and assigning it the value of 1. Results. Partial labrectomy decreased CA (0.82 ± 0.07), increased CP (1.28 ± 0.2) and PF (1.27 ± 0.10) in all measurements compared to the intact labrum (p0.05) except in internal rotation with FLA (0.93 ± 0.03, p=0.03). Although both techniques decrease the CP compared to partial labrectomy (p>0.05), they fail to normalize CP to the intact labrum in all movements of the joint range analyzed (p 0.05) except with FLA in flexion (1.07 ± 0.04, p=0.002) and in external rotation (1.07 ± 0.07, p=0.008). A comparison performed between API and FLA for CA, CP and PF showed no differences in any of the positions of the joint range between the conditions (p>0.05). The labral seal was lost when a partial labrectomy was performed but was restored in 80% of cases with an API reconstruction and in 70% with an FLA reconstruction. Conclusions. In the present biomechanical study carried out in vitro, we conclude that after having performed an anterosuperior partial labrectomy, reconstruction with API and with FLA restores the contact area, normalizes contact pressures and peak forces compared to an anterosuperior partial labrectomy, without observing any differences between these reconstruction techniques.Universitat Autònoma de Barcelona. Programa de Doctorat en Cirurgia i Ciències Morfològique

Trapping cDNAs encoding secreted proteins from the salivary glands of the malaria vector Anopheles gambiae.

The signal sequence trap method was used to isolate cDNAs corresponding to proteins containing secretory leader peptides and whose genes are expressed specifically in the salivary glands of the malaria vector Anopheles gambiae. Fifteen unique cDNA fragments, ranging in size from 150 to 550 bp, were isolated and sequenced in a first round of immunoscreening in COS-7 cells. All but one of the cDNAs contained putative signal sequences at their 5' ends, suggesting that they were likely to encode secreted or transmembrane proteins. Expression analysis by reverse transcription-PCR showed that at least six cDNA fragments were expressed specifically in the salivary glands. Fragments showing a high degree of similarity to D7 and apyrase, two salivary gland-specific genes previously found in Aedes aegypti, were identified. Of interest, three different D7-related cDNAs that are likely to represent a new gene family were found in An. gambiae. Moreover, three salivary gland-specific cDNA fragments that do not show similarity to known proteins in the databases were identified, and the corresponding full length cDNAs were cloned and sequenced. RNA in situ hybridization to whole female salivary glands showed patterns of expression that overlap only in part those observed in the culicine mosquito A. aegypti

Trapping cDNAs coding for receptors and secreted proteins from the salivary glands of the malaria vector Anopheles gambiae.

The salivary glands of mosquito vectors are interesting organs for at least two reasons: (i) they play a crucial role in pathogen transmission and several evidences suggest that recognition and entry of malaria parasite into salivary glands may be mediated by interactions of the ligand-receptor type (Rosenberg R., 1985, Am.J.Trop.Med.Hyg., 34: 687-691; Barreau C. et al., 1995, Exp. Parasitol., 81: 332-343); (ii) they specifically express and secrete substances with antihaemostatic activities (such as anti-coagulants, vasodilators and inhibitors of platelet aggregation) that increase the ability of mosquitoes to efficiently feed on blood (James A.A., 1994, Bull. Inst. Pasteur 92: 133-150). The salivary glands of Anopheles gambiae are still poorly characterized, specially at the molecular level; moreover, the identification of the sporozoite receptor and the isolation of salivary gland-specific promoters would represent important steps toward the design of new vector control strategies based on the development of transgenic mosquitoes incapable of transmitting malaria. In order to identify receptors and secreted proteins expressed in the salivary glands of An. gambiae we used the Signal Sequence Trap (SST) method (Tashiro K. et al., 1993, Science, 261: 600-603) which allows the trapping, through screening in COS-7 cells, of molecules containing signal peptides. In this system a 5'end-enriched cDNA expression library is directionally cloned in an appropriate plasmid vector, between a promoter that confers strong expression in COS-7 cells and a reporter gene, the α-chain of the human interleukin-2 receptor (Tac) lacking the endogenous signal sequence. cDNAs containing a signal sequence and cloned in frame with Tac can be expressed as fusion proteins on the surface of COS-7 cells and can be easily detected by immunostaining with an anti-Tac monoclonal antibody. The cDNA library is screened by transfecting pools of clones in COS-7 cells. Positive pools are divided in sub-pools and re-screened by immunostaining leading to the identification and isolation of single positive clones. We used poly-A(+) RNA from salivary glands of An. gambiae females to construct a 5'end-enriched cDNA expression library and we did our screening in COS-7 cells using the SST method (plasmid vectors were kindly provided from Prof. T. Honjo, Kyoto Univ., Japan). In a first round of screening we were able to isolate eighteen immunofluoruescent positive clones; these cDNA fragments range in size from ~200 to 550 bp and fifteen of them were unique as shown by sequence analysis. All of them, with only one exception, seem to have a signal peptide fused to the reporter gene so they are likely to code for secreted or type I membrane proteins. RT-PCR analysis revealed that five cDNAs are specifically expressed in female salivary glands while other two are expressed both in male and in female glands. As shown by database similarity searches one of these salivary gland-specific clones is the An. gambiae apyrase (see Lombardo F. et al., this meeting) while other three seem to represent different members of a family of proteins that show similarity to the D7 protein of Aedes aegypti (James A.A. et al., 1991, Mol. Biochem. Parasitol., 44:245-254). The remaining three salivary gland-specific cDNA fragments did not show significant similarity to known proteins in the databases. Preliminary results, obtained by RNA in situ hybridization to whole glands, suggest that also in An. gambiae, as in the yellow fever mosquito A. aegypti, female-specific genes are expressed in the distal-lateral and medial lobes while transcripts expressed both in male and in female glands can be localized only in the proximal-lateral lobes. In conclusion using the SST method we have identified the first genes specifically expressed in the salivary glands of the malaria vector An. gambiae. The method worked very efficiently allowing for the trapping of seven salivary gland-specific cDNAs out of 300 clones screened. Several other cDNAs of interest are expected to be trapped by a more exhaustive screening