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Resume Introduction Les abords posterieurs dans les arthroplasties totales de hanche (ATH) sont les plus repandus dans le monde. La luxation represente une des principales complications de cet abord et epargner les structures posterieures pourrait diminuer le risque de luxation. Ainsi, des abords posterieurs epargnant le piriforme (APEP) ont ete decrits. Le taux d’epargne du tendon du muscle piriforme dans cet abord semble satisfaisant ; cependant, une etude cadaverique recente rapporte, pour ce type d’abord, la presence de lesions cachees intrapelviennes du muscle piriforme dans 91 % des cas. Devant cette discordance, nous avons realise une analyse IRM pre- et postoperatoire dans le cadre d’ATH realisees par APEP afin : 1) d’evaluer l’infiltration graisseuse du muscle piriforme induite par cet abord en portant une attention particuliere aux lesions intrapelviennes ; 2) d’evaluer l’infiltration graisseuse de l’ensemble des autres muscles peri-articulaires de hanche induite par cet abord. Hypothese Le muscle piriforme presente une faible infiltration graisseuse a la suite d’APEP. Materiels et methodes Une serie prospective continue mono-operateur d’ATH par APEP comprenant 25 patients a ete realisee. Des IRM ont ete realisees en preoperatoire, puis a 3 mois et 1 an de la chirurgie. L’analyse de l’infiltration graisseuse musculaire selon la classification de Goutallier etait realisee sur l’ensemble des muscles peri-articulaires de hanche. Resultats Quatre patients n’ont pas realise leur IRM preoperatoire et ont ete exclus de l’analyse. Au total, 21 patients, soit 63 IRM, ont ete analyses. Au niveau du piriforme, aucune difference significative n’etait mise en evidence concernant l’infiltration graisseuse entre les IRM preoperatoires et les IRM a 3 mois (p = 0,29) et 1 an (p = 0,41). Deux de 21 patients (9,5 %) presentaient des infiltrations graisseuses de stades 3 a 4 a 1 an de l’intervention contre 0/21 (0 %) en preoperatoire. Ces 2 patients presentaient des desinsertions sacrales du piriforme. Des differences significatives etaient mises en evidence entre les IRM preoperatoires et les IRM a 1 an concernant les muscles obturateur interne et obturateur externe. Au total, 14/21 (66,7 %) des obturateurs internes, 3/21 (14,3 %) des obturateurs externes, et 6/21 (28,6 %) des carres femoraux presentaient une infiltration graisseuse allant d’un stade 3 a 4 a 1 an de l’intervention contre respectivement 0/21 (0 %), 0/21 (0 %) et 3/21 (14,3 %) en preoperatoire. Aucune difference significative n’etait constatee sur l’ensemble des autres muscles peri-articulaires de hanche. Conclusion Les APEP de hanche dans le cadre d’ATH permettent une bonne conservation du muscle piriforme. Des lesions sacrales irreversibles et non visibles en peroperatoire peuvent par contre etre redoutees. Niveau de preuve IV ; serie prospective de cas.

International audience; Introduction: Le choix de l'abord chirurgical pour la réalisation d'une arthroplastie totale de hanche (ATH) ne fait pas consensus en orthopédie. Il existe un regain d'intérêt ces dernières années pour les voies antérieures mini-invasives (VAMI) dites anatomiques. Cependant, leur retentissement minoré n'a pas été confirmé par des imageries. Aussi nous avons mené une étude prospective destinée à : (1) évaluer l'infiltration graisseuse (IG) des muscles péri-articulaires de hanche, (2) analyser l’évolution de cette IG dans le temps. Hypothèse: Une ATH par VAMI induit une IG sur les muscles péri-articulaires antéro-latéraux adjacents à l'abord. Matériels et méthodes: Une série continue mono-opérateur d'ATH par VAMI sur table orthopédique a été réalisée par un opérateur entraîné. Des IRM (1,5Tesla OPTIMA MR360) ont été réalisées en préopératoire, puis à 3 mois et 1 an de la chirurgie. L'analyse de l'IG musculaire selon la classification de Goutallier était réalisée par un radiologue indépendant sur l'ensemble des muscles péri-articulaires de hanche. La comparaison était effectuée entre les IRM préopératoires et celles à 3 mois et 1 an à l'aide de tests de Wilcoxon. Résultats: Soixante-neuf IRM ont été réalisées sur 23 patients. Deux n’étaient pas interprétables du fait de mouvements du patient lors de l'acquisition préopératoire. Aucune complication peropératoire ni postopératoire n'a été rapportée dans cette série après 1 an de suivi. Tous les patients présentaient des hanches indolores sans boiterie à 1 an de l'intervention. L'analyse de l'IG montrait une aggravation significative de cette dernière entre les IRM préopératoires et celles à 3 mois (p = 0,02) et 1 an (p = 0,0007) au niveau du muscle obturateur interne ainsi qu’à 1 an (p = 0,04) au niveau du muscle piriforme. Aucune différence significative n’était retrouvée sur les autres muscles. Le muscle droit fémoral, les muscles jumeaux supérieurs et inférieurs ainsi que le muscle carré fémoral n’étaient pas analysables. Discussion: Notre hypothèse de départ n’était pas confirmée mais nous avons retrouvé un résultat paradoxal avec la mise en évidence d'une IG musculaire, cependant celle-ci n’était pas antéro-externe mais postérieure au niveau des muscles pelvi-trochantériens à la suite d'ATH par VAMI. Ces lésions pourraient être secondaires à des désinsertions ou des dénervations de ces muscles lors de l’élévation du fémur pour l'implantation fémorale. Niveau de preuve: IV; série prospective de cas.

Minimally invasive approaches (direct anterior approach: DAA; minimally invasive anterolateral: MIAL; piriformis-sparing posterior approach: PSPA) are widely used for total hip arthroplasty (THA), with a muscle-sparing objective. There are no published comparative studies of muscle damage secondary to these approaches. The aim of the present study was to compare fatty infiltration (FI) on MRI induced by DAA, MIAL and PSPA in THA 1) in the tensor fasciae latae (TFL) and sartorius muscles, 2) in the gluteal muscles, and 3) in the pelvitrochanteric muscles.Greater FI is induced by DAA in anterior muscles, by MIAL in gluteal muscles and by PSPA in pelvitrochanteric muscles.Three continuous prospective series of THA by DAA, MIAL and PSPA included 25 patients each. MRI was performed preoperatively and at 1 year postoperatively. FI was graded on the Goutallier classification in all periarticular hip muscles. Muscles showing ≥2 grade aggravation at 1 year were considered damaged.Nine patients whose preoperative MRI was uninterpretable were excluded. In all, 66 patients (21 DAA, 24 MIAL and 21 PSPA) with 132 MRI scans were analyzed. TFL was damaged in 2/21 DAA patients (9.5%), 1/24 MIAL patients (4.2%) and 0/21 PSPA patients (0%). There were no sartorius lesions. The anterior third of the gluteus medius was damaged in 8/24 MIAL patients (33.3%) and the gluteus minimus in 10/24 (41.7%), compared to 1/21 DAA patients (4.8%) and 0/21 PSPA patients (0%). The mid and posterior thirds of the gluteus medius and the gluteus maximus were never damaged. The piriformis muscle was damaged in 3/21 DAA patients (14.3%), 2/24 MIAL patients (8.3%) and 2/21 PSPA patients (9.5%). The obturator internus was damaged in 4/21 DAA patients (19%), 1/24 MIAL patients (4.2%) and 16/21 PSPA patients (76.2%). The obturator externus and quadratus femoris were mainly damaged in PSPA patients: respectively, 5/21 (23.8%) and 4/21 patients (19%)).The muscle-sparing properties of minimally invasive hip approaches are only theoretical. In the present series, there were rare TFL lesions with DAA and MIAL. Gluteus medius and minimus lesions were frequent in MIAL. Pelvitrochanteric muscles lesions were more frequent in PSPA, but found in all 3 approaches. These findings should help guide surgeons in their choice of approach and in informing patients about the damage these minimally invasive approaches can cause.III, prospective comparative study.

Clinical and functional improvement after minimally invasive total hip arthroplasty (THA) has become increasingly controversial. The minimally invasive anterolateral approach (MIALA) allows rapid recovery resulting in a reduced need for rehabilitation. Alterations in muscle and static balance have previously been demonstrated. Results in the context of quantified gait analysis (QGA) and MIALA compared to an asymptomatic population remain unknown beyond one year postoperatively. Thus, the main objective of this controlled study was to compare the spatiotemporal parameters of gait, obtained using a QGA, beyond one year postoperatively in subjects operated on for THA by MIALA, with a group of asymptomatic subjects of the same age. The secondary objectives of the study were to compare the other QGA and EMG data acquired in operated subjects with asymptomatic subjects.We hypothesized that QGA and EMG parameters would not normalize beyond one year postoperatively.Thirty-one subjects were recruited, including 16 patients (68 years old; IQR: 65-70) who underwent MIALA, at 15.5 months postoperatively (IQR: 13-17) and 15 asymptomatic subjects (62 years old; IQR: 61-71). Subjects underwent QGA and maximal isometric muscle force tests on the gluteus medius, gluteus maximus, Tensor Fascia Lata (TFL) and Sartorius muscles. Spatiotemporal gait parameters were the primary endpoint. The other QGA parameters: kinetics (characteristic values of vertical ground reaction forces, peak hip moments) and kinematics (hip joint amplitudes and pelvic mobility in the frontal and sagittal plane) constituted the secondary criteria.Five subjects were excluded for unrestored offset. Walking speed was lower in operated patients (1.03m/s versus 1.18m/s, p=0.005). Maximal isometric muscle force moments were lower in patients operated on for the gluteus maximus and medius as well as the TFL (p0.005). The vertical ground reaction forces were lower for the operated patients for the loading phase (FOur hypothesis appears to be validated. Gait deficits persisted beyond one year postoperatively after THA with MIALA. A decrease in walking speed, maximal isometric muscle force of the gluteus medius and gluteus maximus and TFL was observed, as well as a decrease in propulsive force and peak hip moment. Functionally, these results could signify muscle damage following surgery, requiring rehabilitation for improved muscle function.III: Non-randomized controlled trial.

Total hip arthroplasty (THA) on a minimally invasive anterolateral (MIAL) approach frequently leads to gluteus minimus and gluteus medius lesions, and sometimes to tensor fasciae latae (TFL) denervation. We therefore developed compensatory strategies, which we assessed on pre- and post-operative MRI: 1) to assess gluteus minimus and gluteus medius fatty infiltration (FI), 2) to assess TFL FI, and 3) to assess FI in the other periarticular muscles.The modified MIAL approach reduces the rate of gluteus minimus and gluteus medius lesion.A continuous prospective single-surgeon series of THA using a MIAL approach included 25 patients. Femoral implantation was performed with the hip in extension so as to distance the proximal femur from the gluteals, avoiding muscle trauma. The superior gluteal nerve branch in the space between the gluteus medius and TFL, running toward the TFL, was systematically released and protected. MRI was performed preoperatively and at 3 months and 1 year post-surgery. FI was analyzed according to the Goutallier classification in all periarticular muscles.One patient lacked preoperative MRI and was excluded, leaving 24 patients, for 72 MRIs. In 10/24 patients (41.7%) the gluteus minimus and in 8/24 patients (33.3%) the anterior third of the gluteus medius showed ≥2 grade increase in FI between preoperative and 1-year MRI, with significant increases in both at 3 months (p0.001) and 1 year (p0.001). At least a 2 grade increase in FI at 1 year was seen in 1 patient (4.2%) in the TFL, in 2 (8.3%) in the piriformis, and in 1 (4.2%) in the obturator internus. There were no significant differences in FI between preoperative, 3-month or 1-year MRI in any other periarticular muscles.Femoral implantation in hip extension did not reduce the rate of gluteal lesions, which remained frequent. In contrast, release of the superior gluteal nerve branch could be effective in conserving TFL innervation. Some rare lesions of the proximal part of the pelvi-trochanteric muscles were also observed.IV, Prospective case series.

Total Hip Arthroplasty (THA) leads to excellent clinical and functional results. The Minimally Invasive Anterior Approach (MIAA) theoretically allows rapid recovery and a reduction in the need for rehabilitation, but alterations in muscle and static balance have previously been demonstrated. Kinetic, kinematic and muscular alterations have been shown to persist up to 1year postoperatively but data beyond 1year postoperatively is lacking. Thus, the objective of this study was to compare the data from Quantitative Gait Analysis (QGA) coupled with electromyography (EMG), of patients one year postoperatively with THA through MIAA, compared to an asymptomatic control group.We hypothesized that QGA and EMG parameters would not normalize beyond one year postoperatively.Twenty-seven patients were recruited, including 15 subjects (64.6±6.6years) operated on by MIAA, who at 15.9±3.1months postoperatively, along with 12 asymptomatic control subjects (68.9±9.7years), who underwent QGA and maximal isometric muscle strength tests, coupled with EMG on the gluteus medius and maximus, Tensor Fascia Lata (TFL) and Sartorius muscles. The spatiotemporal parameters of walking (step length, walking speed, cadence, single leg support time), kinetics (vertical ground reaction forces, hip moments in the 3 planes) and kinematics (coxofemoral and pelvic amplitudes) were analyzed.The walking speed was lower on the non-operated side of the experimental subjects (0.96msOur initial hypothesis was validated, since walking deficits persisted beyond one year postoperatively after THA through MIAA. A decrease in maximal isometric muscle strength of the gluteus medius and gluteus maximus was observed, as well as an alteration of kinetic and kinematic parameters in the sagittal and frontal planes. The results were in agreement with the literature and reflected the establishment of compensatory mechanisms to overcome alterations in joint strength and range more than one year postoperatively. These results would allow rehabilitation programs to be more specific and would justify a study on the other approaches for THA.III; non-randomized control trial.

Introduction In total hip arthroplasty (THA), the posterior approach is the most common throughout the world. Dislocation is one of the main complications incurred, but the risk may be reduced by sparing posterior structures. Thus, piriformis-sparing posterior approaches (PSPA) were described, and satisfactory conservation of the muscle was reported. On the other hand, a recent cadaver study reported occult intrapelvic piriformis lesions in 91% of cases. In the light of this discordance, we performed pre- and postoperative MRI in THA by PSPA: 1) to assess the fatty infiltration of the piriformis induced by the approach, with particular attention to intrapelvic lesions; and 2) to assess fatty infiltration of the other periarticular muscles. Hypothesis The piriformis muscle will show little fatty infiltration following PSPA. Materials and methods A continuous prospective single-surgeon series of THA by PSPA included 25 patients. MRI was performed preoperatively and at 3 months and 1 year postoperatively. Fatty infiltration was assessed on the Goutallier classification in all periarticular muscles. Results Preoperative MRI was lacking in 4 patients, who were excluded from analysis; 21 patients with MRI were thus analyzed. In the piriformis muscle, there was no significant change in fatty infiltration between preoperative and 3-month (p = 0.29) or 1-year (p = 0.41) MRI. Two of the 21 patients (9.5%) showed grade 3 or 4 fatty infiltration at 1 year, compared to 0/21 (0%) preoperatively; both showed sacral avulsion of the piriformis. Significant differences between preoperative and 1-year MRI were found for the obturator internus and externus, with grade 3 or 4 infiltration at 1 year in 14 cases for the obturator internus (14/21: 66.7%), in 3/21 for the obturator externus (14.3%) and in 6/21 for the quadratus femoris (28.6%), compared to respectively 0/21 (0%), 0/21 (0%) and 3/21 (14.3%) preoperatively. There were no significant differences for any of the other periarticular muscles. Conclusion PSPA in THA ensured good conservation of the piriformis. There may, however, be rare and irreversible sacral lesions invisible intraoperatively. Level of evidence IV; prospective case series.

Resume Contexte Les benefices fonctionnels et cliniques de l’arthroplastie totale de hanche (ATH) par voie mini-invasive sont connus, mais la litterature met en evidence une alteration des parametres de marche et posturaux versus la population generale, notamment pour la voie mini-invasive anterieure (VA) qui degrade davantage les parametres posturaux que la voie posterieure. Cependant l’explication de cette degradation n’est pas connue. Nous avons mene une etude electromyographique de surface (EMGs) des muscles de la hanche pouvant etre touches par la chirurgie (grand gluteal [GMax], moyen gluteal [GMed], tenseur du fascia lata [TFL], sartorius [S]) pour une meilleure comprehension. Ce travail tentait de repondre aux questions : (1) l’activite du GMed est-elle plus importante chez des sujets ayant beneficie d’une ATH par VA en comparaison a des sujets asymptomatiques en bipodal et en unipodal ? (2) Un unique test manuel est-il suffisant pour evaluer la Contraction Maximale Volontaire (CMV) des abducteurs de hanche (GMax, GMed, TFL) et des flechisseurs de hanche (TFL, S) ? Hypothese L’activite du muscle GMed est plus importante chez des sujets ayant beneficie d’une ATH par VA en comparaison a des sujets asymptomatiques en bipodal et en unipodal. Methode Onze patients ayant eu une ATH par VA et 11 sujets asymptomatiques (apparies selon âge, sexe et poids-taille) ont participe a l’etude. Chaque participant a effectue 3 tests posturaux : bipodal yeux fermes (BYF) et unipodal du cote opere (OP) et non opere (nOP). Pour les sujets asymptomatiques, le test unipodal a ete effectue sur les deux membres inferieurs puis moyennes ensembles. L’enregistrement des donnees a ete realise avec 4 electrodes pour EMGs et une plateforme de force. L’activite musculaire EMGs observee durant les tests a ete exprimee comme un ratio de l’activite EMGs des muscles lors d’une CMV afin de normaliser le signal. Resultats Nous avons observe une alteration des parametres posturaux (deplacement et vitesse moyenne du centre de pression) parallelement a une activite EMGs accrue pour les patients operes par VA versus les sujets asymptomatiques (p Discussion L’activite EMGs des abducteurs de hanche, principaux stabilisateurs de bassin, sont recrutes de facon plus importante chez les patients operes par VA. Ceci est en lien avec une deterioration des parametres posturaux. Ce resultat pourrait s’expliquer par une lesion des fuseaux neuromusculaires presents dans les muscles TFL et S au cours de l’acte chirurgical. Cette etude preliminaire sera completee avec des donnees permettant de comparer ensembles les 3 voies d’abord mini-invasives les plus utilisees (anterieure, antero-laterale et posterieure) en suivant le meme protocole. Niveau de preuve III, etude prospective cas-temoins.

The functional and clinical benefit of minimally invasive total hip arthroplasty (THA) is well-known, but the literature reports impaired gait and posture parameters as compared to the general population, especially following use of the anterior minimally invasive approach, which has more severe impact on posture than the posterior approach. The reasons for this impairment, however, remain unexplained. We therefore conducted a surface electromyography (sEMG) study of the hip muscles liable to be affected by arthroplasty surgery: gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S). The study addressed the following questions: (1) Is bipodal and unipodal GMed activity greater following anterior THA than in asymptomatic subjects? (2) Is a single manual test sufficient to assess maximal voluntary contraction (MVC) in hip abductors (GMax, GMed, TFL) and flexors (TFL, S)?Bipodal and unipodal GMed activity is greater following anterior THA than in asymptomatic subjects.Eleven patients with anterior THA and 11 asymptomatic subjects, matched for age, gender and body-mass index, were included. Subjects underwent 3 postural tests: bipodal, eyes closed (BEC), unipodal on the operated side (UOP), and unipodal on the non-operated side (UnOP), with unipodal results averaged between both sides in the asymptomatic subjects. Data were recorded from 4-channel EMG and a force plate. EMG test activity was normalized as a ratio of MVC activity.Postural parameters (mean center of pressure displacement speed) were poorer and sEMG activity higher in anterior THA than asymptomatic subjects (p0.005). On the BEC test, GMax and GMed activity was higher on both operated and non-operated sides than in asymptomatic controls (respectively, 0.15±0.12 and 0.12±0.6 versus 0.07±0.06 for GMax, and 0.13±0.08 and 0.13±0.08 versus 0.08±0.05 for GMed; p0.05). On unipodal tests, both UOP and UnOP GMed activities were higher than in controls (respectively, 0.51±0.3 and 0.48±0.27 versus 0.28±0.13; p0.04); GMax and TFL activities were higher than in controls only on the UOP tests (respectively, 0.49±0.43 versus 0.24±0.18, and 0.23±0.17 versus 0.12±0.16; p0.05).sEMG activity in the hip abductors, which are the main stabilizing muscles for the pelvis, is increased following anterior THA, in parallel with impaired postural parameters. This finding may be due to intraoperative TFL and S neuromuscular spindle lesion. The present preliminary study is to be followed up by a comparison of all 3 common minimally invasive approaches (anterior, anterolateral and posterior) using the same study protocol.III, prospective case-control study.

After total hip arthroplasty (THA), patients continue to have muscular, functional and postural deficits. The literature seems to support the use of postoperative rehabilitation, especially self-directed programs. However, there is no set protocol for the management of postural disorders. Therefore, the purpose of this study was to compare postural parameters of a group of patients who underwent posterior THA followed by 2 different types of rehabilitation (stabilometric platform (SP) and home-based self-directed protocols) with a control group of operated patients who did not undergo rehabilitation and a control group of age-matched asymptomatic subjects.We hypothesized that rehabilitation would normalize the stabilometric parameters.A total of 67 subjects were enrolled in this study (mean age 67.85±1.22years) and divided into 4 groups. Forty-one of these subjects had undergone a posterior THA were randomly assigned between D10 and D21 to one of the following 3 groups: no rehabilitation control group (THACG=14), supervised rehabilitation with a stabilometric platform group (RSPG=16), and a self-directed home-based rehabilitation group (SDHRG=11). The 4th group was a control group made up of 26 age-matched asymptomatic nonoperated subjects (CG55-80). These rehabilitation protocols lasted 3weeks. At the end of the 3weeks, the groups performed the same stabilometric single leg and double leg stance tests (considering lower limb dominance) on an SP.No significant differences were observed between groups in the bipedal stance, except between the CG55-80 and the THACG, where a higher energy expenditure was observed in the THACG during the static stance with eyes open (EO) and eyes closed (EC): increase in the path length (POur results were consistent with the literature on the benefits of rehabilitation after THA, thus confirming our hypothesis that rehabilitation normalized stabilometric parameters between D31-D45, depending on the subjects. These results provide new information regarding rehabilitation techniques to be implemented postoperatively after a THA. A home-based self-directed rehabilitation program is just as effective as an SP program in managing postural disorders.II; randomized controlled trial with low statistical power.

Background Lateralization of the glenoid implant improves functional outcomes in Reverse Shoulder Arthroplasty. Lateralization does not appear to impact the Deltoid’s Moment Arm. Therefore, the stabilizing effect described in the literature would not be the result of an increase this moment arm. A static biomechanical model, derived from Magnetic Resonance Imaging, can be used to assess the coaptation effect of the Middle Deltoid. The objective of this study was to analyze the impact of increasing amounts of glenoid lateralization on the moment arm but also on its coaptation effect. Methods Eight patients (72.6 ± 6.5 years) operated for Reverse Shoulder Arthroplasty were included in the study. Three-dimensional models of each shoulder were created based on imaging taken at 6 months postoperative. A least square sphere representing the prosthetic implant was added to each 3D models. A static biomechanical model was then applied to different planar portions of the Middle Deltoid (from 3D models), first without lateralization and then with simulated lateralization of 6, 9 and 12mm. This static model enables to compute a Coaptation/Elevation Ratio and to measure the Deltoid’s Moment Arm. The inter- and intra-rater agreement of the 3D models was evaluated. Results One patient was excluded due to motion during imaging. The inter- and intra-rater agreement was over 0.99. The ratio increased starting at 6 mm of lateralization (p.05), compared to the initial position. The moment arm was not affected by lateralization (p.05), except in two slices starting at 9 mm (S1 p.05 and S2 p.05). Conclusion Our hypothesis that the Middle Deltoid’s coaptation role would be greater with glenosphere lateralization was confirmed. This trend was not found in the moment arm, which showed little sensitivity to lateralization. The stabilizing effect therefore appears to stem from the coaptation role of the Middle Deltoid.

Resume Contexte Les benefices fonctionnels et cliniques de l’arthroplastie totale de la hanche (ATH) par voie mini-invasive sont bien connus. Cette chirurgie ameliore la qualite de vie des patients, toutefois la litterature met en evidence une alteration de certains parametres fonctionnels en comparaison aux sujets asymptomatiques. En effet, les parametres de la marche et les parametres posturologiques des patients ayant beneficies d’une ATH n’atteignent pas le niveau observe dans la population generale. On observe une alteration notable des parametres posturaux apres une ATH dans toutes les voies d’abord. Cependant, les voies mini-invasives anterieure et anterolaterale degradent davantage les parametres posturaux que la voie posterieure. Une etude electromyographique des muscles de la hanche pouvant etre touches par la chirurgie (grand gluteal [GMax], moyen gluteal [GMed], tenseur du fascia lata [TFL], sartorius [S]) pourrait permettre une meilleure comprehension de ces phenomenes. Cependant, les methodologies decrites dans la litterature existante sur l’evaluation electromyographique de surface (EMG S) sont disparates. Nous avons souhaite dans un premier temps etablir une methode d’evaluation de l’activite EMG S au cours de la contraction maximale volontaire (CMV) des muscles GMax, GMed, TFL et sartorius qui puisse servir de reference. Nous avons ensuite mene une etude prospective visant a repondre a cette question : la position de l’articulation de la hanche et l’apprentissage d’un test de CMV influencent-ils le signal EMG S lors de la CMV ? Hypothese La position de l’articulation de la hanche et l’apprentissage d’un test de CMV influencent le signal EMG S lors de la CMV des muscles GMax, GMed, TFL et sartorius. Methodes Trente sujets jeunes et asymptomatiques ont participe a l’etude. Chacun a effectue 8 CMV des muscles de la hanche dans differentes positions articulaires, enregistrees a l’EMG S par des electrodes de surface. Chaque CMV a ete executee trois fois sur une periode d’une semaine, au meme moment de la journee, avec un controle des niveaux d’activite pendant les 24 h precedentes. L’activite EMG S lors de la CMV a ete exprimee sous forme de rapport d’activite EMG S durant l’appui unipodal. Les comparaisons statistiques ont ete effectuees a l’aide de tests non parametriques. Resultats L’analyse statistique n’a montre aucune difference entre les positions de l’articulation pour l’evaluation du signal EMG S lors de la CMV des abducteurs et des flechisseurs de hanche, sur les trois sessions. Pour les abducteurs de hanche, il n’y avait pas de difference entre les abductions hanche tendue vs hanche flechie executees en decubitus lateral : GMax (19,8 ± 13,7 vs 14,5 ± 7,8, p = 0,78), GMed (13,4 ± 9,0 vs 9,9 ± 6,6, p = 0,21) et TFL (69,5 ± 61,7 vs 65,9 ± 51,3, p = 0,50). Pour les flechisseurs de hanche, il n’y avait pas de difference entre la flexion/abduction/rotation laterale executee en decubitus dorsal ou en station assise : TFL (70,6 ± 45,9 vs 61,6 ± 45,8, p = 0,22) et S (101,1 ± 67,9 vs 72,6 ± 44,6, p = 0,21). Les tests les plus efficaces pour l’evaluation du signal EMG S lors de la CMV etaient pour les abducteurs de la hanche : abduction en decubitus lateral (36,7 % pour GMax, 76,7 % pour GMed), et pour les flechisseurs de la hanche : flexion/abduction/rotation laterale depuis le decubitus dorsal (50 % pour TFL et 76,7 % pour S). Discussion Nous n’avons pas pu confirmer notre hypothese de travail. En effet, la position de l’articulation de la hanche et l’apprentissage d’un test de CMV n’ont pas d’influence sur le signal EMG S lors d’une CMV des muscles GMax, GMed, TFL et sartorius. Une seule session et un seul test suffisent donc pour evaluer la CMV des abducteurs (abduction en decubitus lateral) et des flechisseurs de hanche (flexion/abduction/rotation laterale en decubitus dorsal). Cette methode pourrait etre appliquee a l’evaluation fonctionnelle des muscles apres une ATH, notamment afin de pouvoir comparer les differentes voies d’abord. Niveau de preuve III, etude cas-temoins.

Resume Introduction L’engouement actuel pour les voies d’abord mini-invasives conduit a un regain d’interet pour l’arthroplastie totale de hanche. Les voies anterieure et de Rottinger sont valorisees par leur specificite anatomique et leur caractere mini-invasif, mais aucune etude comparative publiee ne met en evidence une superiorite en termes de qualite de la recuperation fonctionnelle. Dans ce contexte nous avons realise une etude cas–temoins afin d’evaluer si les parametres posturaux des patients operes par voie anterieure et de Rottinger etaient plus proches de ceux des sujets asymptomatiques que ceux des patients operes par voie posterieure. Hypothese Notre hypothese etait que les voies d’abord anterieure et de Rottinger alteraient moins les parametres posturaux que la voie posterieure. Methodes Soixante-dix sujets repartis en quatre groupes ont participe a l’etude. Il y avait, d’une part, un groupe de temoins asymptomatiques ( n = 26) et, d’autre part, trois groupes experimentaux correspondant aux trois voies d’abord mini-invasives : posterieure ( n = 14), anterieure ( n = 15) et Rottinger ( n = 15). Deux tests posturaux en appui unipodal ont ete effectues sur une plate-forme de stabilometrie chez tous les sujets : 10 secondes d’appui sur la jambe gauche, suivies de 10 secondes d’appui sur la jambe droite. Six parametres significatifs ont ete selectionnes pour l’analyse statistique : reussite aux tests et parametres XRa, YRa, PathLength, Vavg et Area95. Le parametre XRa correspond a l’amplitude de deplacement du centre de pression (CDP) en cm selon l’axe mediolateral. Le parametre YRa correspond a l’amplitude de deplacement du CDP en cm selon l’axe anteroposterieur. Le parametre PathLength correspond a la longueur totale parcourue en cm par le CDP. Le parametre Vavg correspond a la vitesse moyenne du CDP, en centimetres/seconde. Le parametre Area95 (Ellipse 95 %) correspond a la surface de l’ellipse (en cm 2 ) contenant 95 % des projections du CDP. Les differents groupes ont ete compares a l’aide de tests statistiques non parametriques. Resultats Les groupes etaient statistiquement homogenes (âge, taille, poids et IMC entre tous groupes) diagnostic et score WOMAC entre groupes experimentaux. Aucune difference statistique n’a ete observee entre les trois voies d’abord mini-invasives concernant la reussite aux tests posturaux unipodaux ( p = 0,14). Les sujets operes par une voie d’abord anterieure ou de Rottinger ont presente des differences statistiques avec les temoins asymptomatiques pour deux parametres posturaux : PathLength (Rottinger p = 0,04, anterieure p = 0,03) et Vavg (Rottinger p = 0,04, anterieure p = 0,03). La comparaison entre les sujets operes par voie posterieure et les temoins asymptomatiques n’a revele aucune difference statistique. Discussion Notre hypothese selon laquelle les voies d’abord anterieure et de Rottinger alterent moins les parametres posturaux que la voie posterieure n’a pas ete verifiee. Pour les sujets operes par voie d’abord anterieure et de Rottinger, les parametres Vavg et PathLength etaient plus eleves, ce qui suggere que la depense energetique de ces patients pour maintenir l’appui unipodal de 10 secondes est plus importante. Nous avons demontre que la voie posterieure perturbe moins les parametres posturaux dans les deux premiers mois postoperatoires. Niveau de preuve III, etude cas-temoins.

Resume Les protheses inversees sont de plus en plus frequemment indiquees dans les reprises d’arthroplastie anatomique. Cette chirurgie est associee a un taux eleve de complications qui a ete reduit par la modularite des gammes prothetiques actuelles, permettant le plus souvent la conversion en conservant le composant humeral. Nous rapportons un cas de reprise de prothese anatomique modulaire mise en place en 1998, en raison d’une usure du polyethylene ayant conduit a une metallose par contact metal/metal. L’implant humeral n’etait pas compatible avec une gamme standard de conversion et il etait realise par le fabricant un adaptateur humeral sur mesure, permettant de conserver la tige humerale. Cette strategie a permis de simplifier notablement l’acte chirurgical dont le resultat anatomique et clinique a ete bon au recul de 9 mois.

Background Minimally invasive total hip arthroplasty (THA) is presumed to provide functional and clinical benefits, whereas in fact the literature reveals that gait and posturographic parameters following THA do not recover values found in the general population. There is a significant disturbance of postural sway in THA patients, regardless of the surgical approach, although with some differences between approaches compared to controls: the anterior and anterolateral minimally invasive approaches seem to be more disruptive of postural parameters than the posterior approach. Electromyographic (EMG) study of the hip muscles involved in surgery [gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S)] could shed light, the relevant literature involves discordant methodologies. We developed a methodology to assess EMG activity during maximal voluntary contraction (MVC) of the GMax, GMed, TFL and sartorius muscles as a reference for normalization. A prospective study aimed to assess whether hip joint positioning and the learning curve on an MVC test affect the EMG signal during a maximal voluntary contraction. Hypothesis Hip positioning and the learning curve on an MVC test affect EMG signal during MVC of GMax, GMed, TFL and S. Methods Thirty young asymptomatic subjects participated in the study. Each performed 8 hip muscle MVCs in various joint positions recorded with surface EMG sensors. Each MVC was performed 3 times in 1 week, with the same schedule every day, controlling for activity levels in the preceding 24 h. EMG activity during MVC was expressed as a ratio of EMG activity during unipedal stance. Non-parametric tests were applied. Results Statistical analysis showed no difference according to hip position for abductors or flexors in assessing EMG signal during MVC over the 3 sessions. Hip abductors showed no difference between abduction in lateral decubitus with hip straight versus hip flexed: GMax (19.8 ± 13.7 vs. 14.5 ± 7.8, P = 0.78), GMed (13.4 ± 9.0 vs. 9.9 ± 6.6, P = 0.21) and TFL (69.5 ± 61.7 vs. 65.9 ± 51.3, P = 0.50). Flexors showed no difference between hip flexion/abduction/lateral rotation performed in supine or sitting position: TFL (70.6 ± 45.9 vs. 61.6 ± 45.8, P = 0.22) and S (101.1 ± 67.9 vs. 72.6 ± 44.6, P = 0.21). The most effective tests to assess EMG signal during MVC were for the hip abductors: hip abduction performed in lateral decubitus (36.7% for GMax, 76.7% for GMed), and for hip flexors: hip flexion/abduction/lateral rotation performed in supine decubitus (50% for TFL, 76.7% for S). Discussion The study hypothesis was not confirmed, since hip joint positioning and the learning curve on an MVC test did not affect EMG signal during MVC of GMax, GMed, TFL and S muscles. Therefore, a single session and one specific test is enough to assess MVC in hip abductors (abduction in lateral decubitus) and flexors (hip flexion/abduction/lateral rotation in supine position). This method could be applied to assess muscle function after THA, and particularly to compare different approaches. Level of evidence III, case-matched study.

The use of tranexamic acid (TXA) in primary total hip arthroplasty is well documented. However, considering the potential side effects, including deep vein thrombosis and pulmonary embolism, the ideal method of providing TXA to patients undergoing total hip arthroplasty remains controversial. The objective of this trial was to assess the efficacy and safety of intravenous (IV) administration combined with topical administration of TXA regarding postoperative blood loss and transfusion rates in patients treated with primary unilateral total hip arthroplasty.In this prospective, randomized controlled trial, 150 patients were divided into three groups: the combined group (IV administration of 15 mg/kg of TXA combined with topical administration of 1 g/100 mL of TXA), the single IV group (IV administration of 15 mg/kg of TXA), and the placebo group. The primary outcomes included blood-loss variables (total, intraoperative, and drainage blood loss; changes in hemoglobin, hematocrit, and platelet concentration; and amount of IV transfusion fluid) and transfusion values (frequency of transfusion and number of transfused blood units). The secondary outcomes included the length of the hospital stay, range of hip motion, Harris hip score, and prevalences of deep vein thrombosis and pulmonary embolism.The total blood loss in the combined group (mean and standard deviation, 835.49 ± 343.50 mL) was significantly reduced (p0.05) in comparison with that in the single IV group (1002.62 ± 366.85 mL) and placebo group (1221.11 ± 386.25 mL). The combined group also had fewer transfusions in comparison with the single IV and placebo groups (1, 8, and 19, respectively; p0.05). There was no difference among the 3 groups with regard to the rates of deep vein thrombosis or pulmonary embolism.Intravenous combined with topical administration of TXA in patients undergoing a primary unilateral total hip arthroplasty significantly reduced postoperative bleeding and the transfusion rate. Studies with more patients and longer follow-up are needed to confirm whether this promising combined strategy is safe with regard to thromboembolic complications.Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

It is generally recognized that the middle deltoid muscle fibers (MDMF) have an elevating effect on the humeral head at small abduction angles. These forces are normally counterbalanced by the coaptation effect of the rotator cuff (RC) muscles to maintain shoulder stability. With RC tears, this balance may be jeopardized leading to shoulder dysfunction. Conversely, not all patients with RC tears develop shoulder dysfunction. The purpose of this study was to investigate the coaptation/elevation forces (CEF) ratio of the MDMF in RC tears subjects and in volunteers, using magnetic resonance imaging (MRI).Magnetic resonance imaging images in 10 subjects with RC tears and in five volunteers were used to build a three-dimensional model of the shoulder. The CEF ratio of the MDMF was estimated by representing the glenohumeral joint as a pulley.The CEF ratio increased from the posterior to the anterior fibers of the MDMF.The median and interquartile range (IQR) of the CEF ratios of the posterior-third, middle-third, anterior-third and anterior-surface segments of the deltoid were: 0.16 (IQR = 0.23), 0.61 (IQR = 0.4), 1.42 (IQR = 0.41), 1.94 (IQR = 0.56) in subjects, and 0.06 (IQR = 0.24), 0.45 (IQR = 0.28), 1.32 (IQR = 1.01), 1.49 (IQR = 0.39) in volunteers. In the subjects, the CEF ratio of the anterior-surface segment was greater than all other segments (P ≤ 0.03).The CEF ratio of the MDMF increased from its posterior segment to its anterior segment, indicating a greater stabilizing effect of the anterior segment both in RC tears subjects and in volunteers. Strengthening of the anterior fibers of the MDMF could potentially improve shoulder function in subjects with RC tears.

Rotator cuff (RC) tears may be associated with increased glenohumeral instability; however, this instability is difficult to quantify using currently available diagnostic tools. Recently, the three-dimensional (3D) reconstruction and registration method of the scapula and humeral head, based on sequences of low-dose biplane X-ray images, has been proposed for glenohumeral displacement assessment. This research aimed to evaluate the accuracy and reproducibility of this technique and to investigate its potential with a preliminary application comparing RC tear patients and asymptomatic volunteers. Accuracy was assessed using CT scan model registration on biplane X-ray images for five cadaveric shoulder specimens and showed differences ranging from 0.6 to 1.4 mm depending on the direction of interest. Intra- and interobserver reproducibility was assessed through two operators who repeated the reconstruction of five subjects three times, allowing defining 95% confidence interval ranging from ±1.8 to ±3.6 mm. Intraclass correlation coefficient varied between 0.84 and 0.98. Comparison between RC tear patients and asymptomatic volunteers showed differences of glenohumeral displacements, especially in the superoinferior direction when shoulder was abducted at 20 and 45 . This study thus assessed the accuracy of the low-dose 3D biplane X-ray reconstruction technique for glenohumeral displacement assessment and showed potential in biomechanical and clinical research. Fondation Paris-Tech Programme BIOMECAM Chaire ParisTech Institut de Recherche Robert-Sauvé en Santé et Sécurité du Travail du Québec Natural Science and Engineering Research Council of Canada Fonds de Recherche sur la Nature et les Technologies du Québec Fonds de Recherche en Santé du Québec, EOS Imaging, and French pôle de compétitivité MEDICEN (STEREOS + program).

This work presents an accurate method to measure gleno-humeral translations in a controlled pseudo-kinematic environment. Low-dose biplanar X-rays were acquired from nine healthy subjects at three elevations of the arm in the scapular plane. On each set of images, shoulder bony landmarks were manually located in 3D using a dedicated software. Intra-observer and inter-observer repeatability of landmark identification, as well as humeral head center (GH) translations, were studied. Repeatability for the identification of GH in the global coordinate system (CS) was good with 95% confidence intervals (CIs) ranging from 0.57 to 2.25 mm. Scapular landmark CIs ranged from 0.80 to 12 mm. Gleno-humeral translations of small amplitude (

La reeducation musculaire occupe une place centrale dans la prise en charge des ligamentoplasties du genou. En effet celle-ci intervient a la fois pour stabiliser activement l’articulation et pour mecaniser le transplant. La ligamentisation, periode durant laquelle le greffon acquiert les caracteristiques d’un LCA sain, necessite une annee. Les 6 premieres semaines consistent en une phase inflammatoire. Des 6 semaines, le greffon est enveloppe dans une synoviale vasculaire. De 6 semaines a 3 mois, la vascularisation se met en place et le tendon est transforme en neo-ligament. A 6 mois, le neoligament semble similaire en morphologie, densite cellulaire, alignement collagenique et vascularisation au LCA intact. Le protocole de renforcement musculaire doit se superposer au phenomene de ligamentisation afin de mecaniser le transplant sans le leser. Un travail precoce (a partir de la 6e semaine) du quadriceps en CCO avec les precautions d’usage n’est pas nefaste, il contribue au contraire a l’amelioration de la stabilite articulaire. Une association precoce des renforcements musculaires en CCO et CCF semble garantir une recuperation optimale de la fonction du genou.

Reverse shoulder arthroplasty (RSA) is increasingly being used to revise anatomical total shoulder arthroplasty cases. This procedure's high complication rate has been reduced by the availability of modular shoulder systems, which allows the humeral component to be preserved during the conversion. This case report describes the revision of an anatomical shoulder implant inserted in 1998. Polyethylene wear and the resulting metal-on-metal contact had caused metallosis. Since the existing humeral implant was not compatible with standard conversion products, the manufacturer provided a custom humeral adapter that allowed the humeral stem to be preserved. This approach greatly simplified the surgical procedure and resulted in good anatomical and clinical outcomes after 9 months of follow-up.

A robust and reproducible scapular coordinate system is necessary to study scapulo-thoracic kinematics. The coordinate system recommended by the ISB (International Society of Biomechanics) is difficult to apply in studies using medical imaging, which mostly use a glenoid-centered coordinate system. The aim of this study was to assess the robustness of a glenoid-centered coordinate system compared to the ISB coordinate system, and to study the reproducibility of this coordinate system measure during abduction. A Monte-Carlo analysis was performed to test the robustness of the two coordinate systems. This method enabled the variability of the orientation of the coordinate system to be assessed in laboratory setting. A reproducibility study of the glenoid-centered coordinate system in the thorax reference frame was performed during abduction in the scapular plane using a low-dose stereoradiography system. We showed that the glenoid-centered coordinate system was slightly more robust than the ISB-recommended coordinate system. Most reproducible rotation was upward/downward rotation (x axis) and most reproducible translation was along the Y axis (superior-inferior translation). In conclusion, the glenoid-centered coordinate system can be used with confidence for scapular kinematics analysis. The uncertainty of the measures derived from our technique is acceptable compared to that reported in the literature. Functional quantitative analysis of the scapular-thoracic joint is possible with this method. We would like to thank Guillaume Simer and Benjamin Aubert for their technical support. Funding: IRSST, ParisTech BiomecAM Chair, Société Générale and Covea.

Noninvasive methods enabling measurement of shoulder bone positions are paramount in clinical and ergonomics applications. In this study, the acromion marker cluster (AMC) method is assessed in comparison with a model-based approach allowing scapula tracking from low-dose biplanar radiograph images. Six healthy male subjects participated in this study. Data acquisition was performed for 6 arm abduction positions (0°, 45°, 90°, 120°, 150°, 180°). Scapula rotations were calculated using the coordinate systems and angle sequence was defined by the ISB. The comparison analysis was based on root mean square error (RMSE) calculation and nonparametric statistical tests. RMSE remained under 8° for 0° to 90° arm abduction and under 13.5° for 0° to 180° abduction; no significant differences were found between the 2 methods. Compared with previous works, an improved accuracy of the AMC approach at high arm abduction positions was obtained. This could be explained by the different sources of data used as the “gold standard.”

La prise en charge du lombalgique chronique est un probleme de Sante Publique majeur. En tant que praticien, nous devons essayer de proposer des solutions pour rendre le patient autonome et acteur de sa reeducation. Au praticien de gerer pour le mieux les differents temps de sa prise en charge.

Introduction L’arthroplastie totale de hanche donne d’excellents resultats La litterature internationale relate neanmoins des deficits qui concernent la fonction d’equilibration. La VALMI presente des parametres posturaux qui sont plus alteres que ceux de la VP. Hypothese Les patients ayant beneficies d’un protocole de reeducation presentent des parametres posturaux qui sont normalises pour ces deux voies d’abords. Materiel et methodes Quatre groupes controles, deux echantillons de sujets asymptomatiques de tranche d’âge 18–30 ans (n = 48) et 55–80 ans (n = 26) Deux echantillons de sujets de tranche d’âge 55–80 ans ayant beneficies d’une arthroplastie de hanche VP (n = 14) ou VALMI (n = 14) 4 groupes beneficient d’un programme de reeducation Deux echantillons de sujets operes par VALMI (n = 14) et VP (n = 14) de tranche d’âge 55–80 ans recoivent une reeducation specifique de l’equilibre sur plate-forme de force (PFF). Deux echantillons de sujets operes par VALMI (n = 14) et VP (n = 14) recoivent un programme d’auto reeducation a domicile. Tous les sujets operes ont etes inclus dans notre etude en serie continue. Tous les sujets recrutes dans le cadre de cette etude sont evalues sur une PFF en station bipodale et en station unipodale (entre j45 et j60 pour les sujets operes). Resultats Parametres bipodaux yeux fermes, les sujets operes non reeduques presentent des une alteration des parametres posturaux par rapport aux sujets controles de tranche d’âge 55–80 ans (+ 0,03). Les sujets reeduques ne presentent pas ces differences. Les resultats pour la VP sont meilleurs que pour la VALMI (+ 0,02). Parametres unipodaux amelioration de la reussite aux tests pour tous les groupes reeduques. En comparaison avec les sujets asymptomatiques de tranche d’âge 55–80 ans, les sujets reeduques presentent de meilleurs resultats pour la VP et equivalent pour la VALMI. Les deux protocoles ont des effets equivalents pour la voie posterieure. La reeducation a domicile est moins efficace pour les patients operes par VALMI (+ 0,03). Discussion La reeducation ameliore les parametres posturaux pour tous les patients operes. La VP presente des resultats qui sont meilleurs que la VALMI et notamment pour l’equilibration antero-posterieur. Les deux protocoles de reeducation sont aussi efficaces l’un que l’autre en VP. Le protocole de reeducation sur PFF est plus efficace que l’auto-reeducation pour le groupe VALMI. L’hypothese est donc partiellement confirmee. Nous pensons que ces differences sont en lien avec les qualites proprioceptives du muscle TFL qui peut-etre lese par les ecarteurs en VALMI. Nous preconisons le protocole d’auto-reeducation pour la VP et la reeducation sur PFF pour la VALMI. Pour la VALMI, nous pensons qu’un travail neuromusculaire plus intensif dans le plan sagittal pourrait ameliorer nos resultats.

Introduction L’acide tranexamique (TXA), utilise essentiellement par voie intraveineuse (IV), permet de limiter avec efficacite les pertes sanguines dans l’arthroplastie totale de genou. Notre hypothese etait que, l’administration combinee intraveineuse et locale d’acide tranexamique, permettait de reduire les pertes sanguines par rapport a l’administration intraveineuse seule. Materiel et methodes Cette etude prospective randomisee, controlee contre placebo, en double aveugle inclus une serie continue, mono-operateur, de 74 patients operes de prothese tricompartimentale unilaterale de genou de premiere intention : 22 sous antiagregant plaquettaire (AAP) (groupe A), 52 sans traitement modifiant l’hemostase (groupe B). Tous beneficierent de 15 mg/kg de TXA IV a l’induction, en fin d’intervention puis a 8 h et 15 h postoperatoire. Chacun fut randomise pour recevoir en intra-articulaire du TXA ou un placebo. L’operateur n’etait pas informe du contenu. Le critere de jugement principal etait la perte sanguine totale calculee au quatrieme jour postoperatoire en fonction du taux d’hemoglobine. Les analyses separerent les patients sous AAP et sans traitement modifiant l’hemostase. Resultats Dans le groupe A : 10 ont eu du TXA local et 12 du placebo. Dans le groupe B : 23 ont eu du TXA local et 29 du placebo. L’analyse des pertes sanguines ne montrait pas de difference significative entre les patients recevant le TXA local ou les patients recevant le placebo que ce soit dans le groupe A (p = 0,16) ou le groupe B (p = 0,39). Aucune difference significative entre les patients recevant le TXA local qu’ils soient sous AAP ou sans traitement (p = 0,48). Aucun patient ne fut transfuse. Discussion Cette etude ne montre pas de superiorite a l’utilisation combinee de TXA, en comparaison a la forme IV seule, que les patients soient sous AAP ou sans traitement modifiant l’hemostase. Neanmoins, l’absence de difference significative entre les patients recevant le TXA local, qu’ils soient sous AAP ou sans traitement, traduirait peut etre un benefice a l’administration combinee pour les patients sous AAP. Une poursuite de l’etude avec un effectif plus important sera necessaire pour apprecier ce parametre. Conclusion Notre hypothese de depart n’est pas confirmee.

Background Alterations of the scapular kinematics in different pathologic conditions have been widely studied. However, results have shown considerable discrepancies concerning the direction and the amplitude of scapular movement. The lack of consistency in the literature probably has several explanations. The purpose of this study was to analyze scapular orientation with the arm at rest and with 90° lateral elevation in healthy and pathologic subjects by use of stereoradiographs. Materials and methods All participants (n = 65) underwent a clinical examination and magnetic resonance imaging of the shoulder to assess rotator cuff status. Participants were separated into 3 groups: healthy, rotator cuff tear (RCT), and RCT and subacromial impingement syndrome (RCT+ SIS). A 3-dimensional model of the scapula was fitted to each low-dose stereoradiograph acquired with the arm at rest and 90° arm elevation. Results Orientation of the scapula with the arm at rest was not significantly different between groups. During lateral elevation, scapular orientation was not significantly different between the healthy group and the RCT group. However, upward rotation was significantly reduced in the RCT + SIS group. Conclusion Alterations of scapular kinematics in symptomatic subjects are multifactorial. We observed a link between clinically assessed subacromial impingement and scapular orientation during lateral elevation of the arm. Funding: IRSST, ParisTech BiomecAM Chair, Société Générale, and Covea.

Les attelles du genou sont classiquement prescrites dans les suites operatoires des ligamentoplasties. Elles n’ont pourtant pas prouve leurs effets benefiques lors d’etudes comparatives sur les parametres musculaires, que ce soit lors de tests analytiques ou plus fonctionnels. En outre elles ne protegent pas efficacement le transplant pour les sollicitations de la vie quotidienne. Elles procurent cependant au patient une sensation de stabilite. Le rapport cout/benefice n’est donc pas en faveur des attelles articulees, nettement plus onereuses que les ortheses rigides. Dans les suites post-operatoires d’une chirurgie de reconstruction du LCA, les auteurs preconisent le port d’une attelle rigide jusqu’a l’obtention du « verrouillage actif » du quadriceps.

Background Though several glenoid implants were developed over the past years, a high rate of glenoid loosening remains. This complication is linked to the glenohumeral stability, defined as humeral head translation. In an intact shoulder, this concept is ensured by all active and passive elements, particularly the labrum. Two features of a glenoid implant can be adjusted to improve the stability, or, in other words, to decrease the translations: the first is the mismatch, defined as the difference of curvature between the prosthetic head and glenoid; the second is the shape of the glenoid component. Therefore, the objective of this study was to compare the performance of 2 glenoid components (Ceraver, Roissy, France): (1) a standard design and (2) a design named “labrum design” with a superior part simulating the anatomic labrum. Methods An experimental device was developed to evaluate forces and kinematics. The device simulated active, dynamic and continuous abduction of an entire arm. It reproduced the Scapulo-Humeral Rhythm. The labrum design was installed first. To evaluate the effect of mismatch on the glenohumeral stability, 3 humeral heads were tested, corresponding to the ones recommended by the company. The experiment was repeated for the standard design. Findings The results obtained show a general decrease of the prosthetic head translation with the labrum design compared to the standard design. No noticeable effect of mismatch was found. Interpretation A proof of concept of the interest of the artificial labrum was provided since it improved the glenohumeral stability.

Accurate knowledge of the scapular anatomy is fundamental for the preoperative evaluation but some bony landmarks are difficult to identify. Statistical approaches based on subject-specific parametric models could be used to overcome this difficulty. The aim of this study was to propose a quantitative parametric model of the scapula and to analyze correlations between descriptive morphologic parameters.Forty-three scapulae were scanned and reconstructed. Each 3D scapula was regionalized and a simple geometric element was best fitted on each region using least square method. Descriptive parameters of each region were obtained. Correlation and linear regression analyses were performed between all measurements in order to assess parameters that can be used as predictors of the other descriptive parameters.Morphometric scapular measurements from 3D reconstructions were obtained. Correlation and linear regression analyses assessed correlations between the glenoid width and both the glenoid height and the acromial width. Also, we obtained correlation between the orientation of the inferior part of the acromion on the A-P view and on the axillary view.Parametric models are widely used in biomechanics for identifying anatomical landmarks or rotations centers of these structures. For the scapula, no such model is available. We elaborated a first parametric model of scapula based on a large database of 43 scapulae. Our morphometric measurements are very close to others founded in literature. Correlations obtained should help to progress toward relevant subject-specific models of the scapula based on reduced information.

La chirurgie mini-invasive anatomique de la hanche connait actuellement un succes grandissant. Les principaux avantages de cette chirurgie sont fonctionnels et s’observent uniquement a court terme. Il n’existe pas d’etude ayant comparee o l’equilibre O postural des patients operes d’une prothese totale de la hanche selon les trois voies d’abord les plus pratiquees. Dans ce contexte, l’objectif de l’etude est d’evaluer les effets produits par le choix de la voie d’abord sur l’equilibre o postural O en appui bipodal apres l’implantation d’une PTH. Materiel et methode Au total, 145 sujets volontaires divises en 5 groupes ont participes a l’etude (2 Groupes temoins comportant 100 sujets asymptomatiques – 50 sujets dont la tranche d’âge est comprise entre 20 et 30 ans50 sujets dont la tranche d’âge est comprise entre 55 et 80 ans et 3 groupes experimentaux comportant 45 sujets – 15 sujets voie anterieure, 15 sujets voie posterieure et 15 sujets voie antero-laterale mini-invasive). L’echantillon constituant les 3 groupes experimentaux ont etes operes par 3 chirurgiens experimentes dans l’arthroplastie de hanche, pratiquant chacun une voie d’abord differente. Chaque sujet a ete evalue sur une plate-forme de force AMTI AccuGaity en appui bipodal selon deux conditions – yeux ouverts et yeux fermes. De plus, tous les sujets operes ont repondu a un questionnaire fonctionnel (WOMAC) et ont realises les tests entre j45 et j60. Resultats Aucune difference significative n’est retrouvee entre les trois voies d’abord au niveau du score de WOMAC preoperatoire (&#961 + =0,335 NS). Yeux ouverts – L’analyse statistique a montre des differences significatives entre les groupes pour la Vmoy (&#961 + =0,003*) et la longueur (&#961 + = 0,003*). Les sujets operes par VALMI et par VA ont une longueur significativement plus grande (&#961 + =0,05* pour VA et &#961 + =0,03* pour VdR) par rapport aux sujets temoins ainsi qu’une Vmoy du centre de pression plus elevee que ces derniers (&#961 + =0,05* pour VA et &#961 + =0,03* pour VdR). Pour les sujets operes par VP, il n’existe pas de difference significative par rapport aux groupes temoins. Yeux fermes – L’analyse statistique a mis en evidence des differences significatives entre les groupes pour la Vmoy (&#961 + =0,003*), la longueur (&#961 + = 0,003*) et l’ellipse (&#961 + =0,010*). La voie posterieure est la seule a ne pas presenter de difference statistiquement significative par rapport aux groupes temoins. Discussion La VP est la voie d’abord qui presente les parametres posturaux qui sont les plus proches des sujets temoins. Les groupes VA et VALMI ce distinguent statistiquement des groupes temoins. Les auteurs pensent que les muscles TFL et sartorius ont un role proprioceptif important et peuvent etres leses lors de la mise en place des ecarteurs pour les VA et VALMI.

To investigate the reproducibility of shoulder bony landmarks location using the EOS® low-dose stereoradiography system, in order to validate this new tool for the study of gleno-humeral pseudo-kinematics. An inter and intraobserver reproducibility study of shoulder bony landmarks location concerning 22 healthy volunteers. This study concerned the neutral position, arm at rest. Humerus and scapula were modeled with simple geometric shapes using specific software. Those shapes were positioned on A-P and lateral x-rays views. Images analysis of the 22 subjects was carried out three times (n r = 3), by two observers (n o = 2), for a total of n tot = 132 analyses. We obtained a very good reproducibility for the humeral head center and the diaphysis axis with 95% confidence interval (IC95%) inferior to 1.09 mm and 0.41°, respectively. The uncertainty was higher for the lateral and medial epicondyles. Regarding the scapular bony landmarks, we observed a good reproducibility for the tip of the coracoid process, the inferior glenoid rim, and the axillar border with a 95% confidence interval lower than 2.13, 2.91 mm, and 3.67°, respectively. The uncertainty was higher for the most postero-lateral point of the acromion and the superior glenoid rim. Our analysis of the x-rays obtained with the EOS® low-dose stereoradiography system assessed the location reliability and reproducibility of specific scapular and humeral bony landmarks. This work opens the way to gleno-humeral pseudo-kinematics analysis using EOS® imaging system.

Introduction La generalisation des voies d’abord mini-invasives a conduit, ces dernieres annees, a une modification de la prise en charge des patients operes de prothese totale de hanche. La tendance actuelle est d’obtenir une recuperation rapide. La litterature internationale rapporte de nombreux deficits chez les patients porteurs de PTH. Des etudes recentes ont notamment constate des troubles de l’equilibre postural statique chez les patients porteur de PTH. Dans ce contexte, l’objectif de l’etude est de tester l’hypothese selon laquelle les patients operes ayant subit une reeducation postoperatoire ont de meilleurs parametres d’equilibre posturaux que ceux non reeduques. Patients et methode Quatre-vingt-treize sujets, repartis dans 5 groupes, dont 2 groupes temoins (30 sujets jeunes asymptomatiques et 21 sujets asymptomatiques de meme tranche d’âge que les patients porteurs d’une PTH) ont ete recrutes pour cette etude. Les sujets operes de prothese de hanche ont ete repartis de maniere aleatoire en 3 groupes. Un groupe ne suit pas de reeducation (14 patients), un groupe suit une auto-reeducation a domicile de 3 semaines avec une supervision telephonique bi-hebdomadaire (14 patients), et le dernier groupe realise un protocole de reeducation sur plate-forme de force (PFF) (14 patients) supervise par un kinesitherapeute d’une duree de 3 semaines egalement. Chacun des groupes realise les memes tests d’equilibre statique en station bipodale et unipodale a l’issue du programme et entre j45–j60. Resultats Les resultats confirment l’hypothese de depart de maniere statistiquement tres significative. Ces evolutions favorables concernent les deux positions de test - statique bipodale, et statique unipodale. Il n’existe pas de difference statistiquement significative entre le groupe temoin de sujets âges asymptomatiques et le groupe ayant suivi le programme d’auto reeducation. En revanche le groupe reeducation sur PFF a des resultats qui sont meilleurs que ce meme groupe temoin (p = 0,01). Enfin, il n’existe aucun echec au test unipodal 15 s pour tous les patients reeduques (auto-reeducation ou reeducation PFF) alors que pour le groupe sans reeducation le taux d’echecs est de 40 %. Discussion Les resultats s’accordent avec ceux de la litterature sur l’efficacite et l’interet d’un protocole de reeducation apres prothese de hanche. Chacun des protocoles de reeducation a permis aux patients de contrecarrer les deficits de l’equilibre statique observes apres prothese de hanche mais egalement de surpasser les resultats des patients consideres comme assymptmatiques de la meme tranche d’âge. Ces resultats permettent d’apporter de nouveaux indices sur les techniques a adopter en phase precoce chez les patients operes de PTH. Un programme a domicile avec suivi proche est efficace pour les patients etant capables de le suivre. L’utilisation d’un programme sur PFF est egalement un outil viable pour ameliorer l’equilibre en phase precoce que le kinesitherapeute doit envisager l’utilisation.

Introduction Les 3 voies d’abord mini-invasives principales pour l’arthroplastie totale de hanche sont – la voie posterieure (VP), la voie de Rottinger (VR) et la voie anterieure (VA). Leurs benefices fonctionnels precoces sont reconnus par tous. Neanmoins, l’equilibre postural statique, evalue sur plateforme de force revele une degradation significative des parametres posturaux des sujets operes par rapport aux sujets temoins. Les sujets operes par VP ont les parametres posturaux les plus proches des sujets temoins. Objectifs Cette etude comparative, controlee, multicentrique (VP, VA, VR) est realisee en postoperatoire et a pour objectif de mettre en place une methode reproductible afin d’analyser le signal EMG des muscles de la hanche en parallele de l’etude de l’equilibre postural statique sur plateforme de force. Patients et methode Cinq groupes, dont 2 groupes temoins (30 sujets entre 18–30 ans et 10 sujets entre 55–80 ans) et 3 groupes PTH de 10 sujets chacun (VA, VR et VP) participent a cette etude. Les sujets operes sont evalues entre j45 et j60 postoperatoires. Les donnees sont recueillies a partir d’une plateforme de force et d’un EMG de surface a 4 voies (grand gluteal, moyen gluteal, TFL et sartorius) et 2 goniometres electroniques (coxo-femorale, tibio-tarsienne). Tous les sujets realisent 8 tests de force maximale isometrique pour la normalisation du signal EMG et 6 tests posturaux, en position bipodale avec et sans perturbation exterieure puis unipodale. Resultats Les resultats mettent en evidence une activite importante au sein des groupes temoins du sartorius et du TFL comparativement aux autres muscles. Par ailleurs, il existes des differences concernant l’activite musculaire entre les 3 voies d’abord et les groupes temoins (p = 0,01). Notamment, en appui unipodal l’activite du sartorius augmente dans les groupes PTH VA en VR en comparaison aux groupes temoin (PA – 9 A 4,1 vs 1,6 A 1,3 + PN – 21,2 A 10,3 vs 2,3 A 3,6) et au groupe VP (p = 0,01). Discussion Cette etude est la premiere a s’interesser a l’activite EMG des muscles touches par l’arthroplastie totale de hanche, en lien avec l’equilibre postural statique. Les resultats dans le groupe temoin 18–30 ans montrent que le sartorius joue un role particulier dans le maintient de cet equilibre. La modification de l’activite electrique des muscles sartorius et TFL pour les sujets operes par VA et VR pourraient expliquer l’alteration de l’equilibre postural qui est plus marque pour ces voies. Ces muscles riches en fuseaux neuromusculaires agiraient au sein de la hanche comme un veritable regulateur de la posture.