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Limiting the risk of dislocation is one of the main aims of both dual mobility and Lefevre retentive cups. However, these devices have never been compared. The goal of our study was to compare these devices in total hip arthroplasty revisions for instability. The judgement criterion was non-recurrence of dislocation in a follow-up period of eight years. This retrospective case-control study compared two continuous paired series of total hip arthroplasty revisions for instability. These series included 63 patients and 159 patients with implantation of a Lefevre retentive cup and a dual mobility cup, respectively. The success rate at eight years (i.e., no recurrence) was 91 ± 0.05% and 95 ± 0.02% in the Lefevre retentive cup and dual mobility groups, respectively. The difference was not statistically significant (p = 0.6). It seems that the Lefevre retentive cup provides comparable outcomes with the dual mobility cup in the total hip arthroplasty revisions for instability, avoiding recurrence in long term.

Resume Introduction Le brochage-cerclage (ou brochage-haubanage) est considere comme le traitement standard des fractures transversales de l’olecrane. Ses principales complications sont la migration des broches et la gene engendree par le materiel. Nous avons concu et utilise des broches anti-expulsion (BAE), dont le design previent la migration et reduit la gene sur materiel. Cette etude comparait les taux de migration et des autres complications entre ces broches anti-expulsion et les classiques broches de Kirschner (groupe controle). Hypotheses Les BAE presenteraient des taux de migration et de complications plus faibles que les broches de Kirschner standards. Materiel et methodes Etude des donnees patients, retrospective, monocentrique, multi-operateur, observationnelle, de janvier 1996 a decembre 2014. Le critere de jugement principal etait la survenue de migration de broche. Les criteres de jugement secondaires etaient la survenue d’une ou plusieurs autres complications et le taux d’ablation du materiel. Resultas Ont ete inclus 101 patients : 53 (52,4 %) dans le groupe avec broches anti-expulsion (BAE) et 48 (47,6 %) dans le groupe controle. Aucun cas de migration n’a ete retrouve dans le groupe BAE, contre 21 cas (43,7 %) dans le groupe controle (p Conclusion Les broches anti-expulsion ont toute leur place dans le traitement des fractures de l’olecrane par brochage-cerclage : elles ne migrent pas, et reduisent les taux de complications, de gene, de deplacement secondaire et d’ablation du materiel. Niveau de preuve III, Etude comparative retrospective.

Tension band wiring is considered the standard treatment for transverse olecranon fractures. Its main complications are pin migration and discomfort caused by the hardware. We have designed and used "expulsion-proof" pins (EPP) that are shaped to prevent migration and reduce discomfort. This study compared the complication rate between our device and Kirschner pins (controls).We hypothesised that EPP would have lower migration rates and fewer complications than standard Kirschner pins.This retrospective, single-center, multi-operator, observational, study examined data from January 1996 to December 2014. The primary outcome was the occurrence of pin migration. Secondary outcomes were the occurrence of one or more additional complications and the hardware removal rate.The study enrolled 101 patients: 53 (52.4%) with expulsion-proof pins and 48 (47.6%) controls. The mean follow-up was 240.6days in the EPP group and 268.9days in the control group. No cases of migration (0%) were found in the EPP group versus 21 (43.7%) cases in the controls (p0.05). One or more complications occurred in 18 (33.9%) patients in the EPP group versus 46 (95.8%) controls (p0.05). There was material discomfort in 13 (24.5%) cases and 1 (1.9%) case of secondary displacement in the EPP group, compared with 38 (79.2%) and 7 (14.6%) cases, respectively, in the controls (p0.05). The rate of delayed consolidation was statistically identical in the two groups (p=0.103). The hardware was removed in 13 (24.5%) cases in the EPP group compared with 36 (75%) controls (p0.05).EPPs are useful for management of olecranon fractures treated via TBW: the pins do not migrate and can reduce complications, discomfort, secondary displacement, and the hardware removal rate.Level III, retrospective comparative study.

In computer-assisted orthopedic surgery, the hip center (HC) can be determined by calculating the center of rotation of the femur in relation to the pelvis. Several methods are available: Gamage, Halvorsen, Pivot or Least-Moving Point (LMP). To our knowledge, no studies have compared these four methods. We therefore conducted in silico and in vitro experiments to assess whether their accuracy and precision in locating the HC and calculating the hip-knee-ankle (HKA) angle were equivalent.The four methods show similar accuracy and precision.The in silico experiment assessed the independent influence of four parameters (camera noise, acetabular noise, movement amplitude, and number of circumductions) on accuracy. The accuracy and precision of the four methods and the impact on HKA ankle calculation were assessed in an in vitro study on six cadaver limbs.In the in silico experiment, all differences according to method were significant (p0.0002). The Pivot method was the most accurate for acetabular and camera noise, number of circumductions, and movement amplitude. With the LMP, Pivot, Gamage and Halvorsen methods, error was respectively 23.07±8.40 (range 2.10-54.67) mm, 1.98±081 (0.15-4.89) mm, 28.18±3.42 (18.57-37.60) mm and 2.84±1.46 (0.11-9.44) mm depending on camera noise, 1.65±0.72 (0.13-4.80) mm, 0.52±0.22 (0.05-1.23) mm, 3.02±0.57 (0.60-4.78) mm and 0.61±0.27 (0.04-1.82) mm depending on movement amplitude, 0.50±0.20 (0.05-1.34) mm, 0.18±0.08 (0.01-0.44) mm, 0.36±0.14 (0.03-0.80) mm and 0.21±0.09 (0.01-0.55) mm depending on number of circumductions, and 11.30±5.77 (0.56-37.87) mm, 2.78±1.47 (0.10-8.77) mm, 88.08±8.85 (60.59-117.79) mm and 24.33±9.82 (1.40-66.17) mm depending on acetabular noise. In the in vitro experiment, differences were non-significant between the Pivot and LMP methods (p0.98) and between the Gamage and Halvorsen methods (p0.65). With the LMP, Pivot, Gamage and Halvorsen methods, precision was respectively 8.2±4.6 (3.3-23.6) mm, 7.3±3.6 (3.4-14.1) mm, 33.6±19.1 (4.7-111.4) mm and 35.0±25.0 (4.7-132.5) mm. Accuracy was 13.5±8.2 (3.2-40.7) mm. 12.3±6.4 (3.2-23.6) mm, 47.0±33.3 (6.2-176.6) mm and 40.3±27.8 (6.1-130.3) mm. The LMP and Pivot methods were thus more accurate and more precise than the Gamage and Halvorsen methods. HKA angle error was 1.1±0.9° (0.1-3.7) and 0.9±0.8° (0.0-2.5) with the LMP and Pivot methods, and 3.2±2.7° (0.0-12.7) and 3.8±3.5° (0.0-13.3) with the Gamage and Halvorsen methods.The study highlighted differences between the four methods of HC location in computer-assisted surgery; the Pivot method was the most accurate and precise, thus falsifying the study hypothesis.III, prospective comparative in silico and in vitro study.

Resume L’interet pour les voies d’abord permettant la pose d’une prothese totale de hanche reste eleve, mais sans veritable consensus. Plusieurs artifices techniques recents ont permis de diminuer les risques de luxation et d’ameliorer ainsi l’efficacite de la voie d’abord postero-laterale. Depuis 2003, nous utilisons une voie d’abord postero-laterale mini-invasive modifiee dite SPARTAQUUS (« Spare the Piriformis And Respect The Active QUadratus femoris and gluteus mediUS ») qui respecte le tendon du muscle piriforme (piriformis), le muscle carre femoral (quadratus femoris), le muscle moyen fessier (gluteus medius) et qui implique une suture capsulaire directe. Ainsi l’effet « hamac postero-superieur actif » du tendon du muscle piriforme est couple a l’effet « hamac postero-superieur passif » de la suture capsulaire, limitant ainsi les risques de luxation posterieure de l’articulation prothetique.

The Lefèvre retentive cup is a salvage solution for total hip replacement at high risk of dislocation. Only a few studies have reported the medium or long-term survival; most often, only a small number of patients were included in these studies. This led us to conduct a retrospective analysis of a large population to determine: 1) the 10-year survival rate after primary or revision arthroplasty, 2) the complication rate.The dislocation rate is5% for revision arthroplasty and2% for primary arthroplasty.This single-center retrospective study included 466 consecutive total hip replacements performed with the Lefèvre retentive cup with a 12-year theoretical minimum follow-up (1/1/1998 to 31/8/2006). There were 257 indications for primary arthroplasty and 209 for revision arthroplasty. The cohort had 316 women and the mean age at surgery was 72.9years (30.2-89.9). The mean follow-up was 10.2±5 years (0.1-19.3). A statistical analysis was done based on the Kaplan-Meier survival curves in two subsets of patients: primary and revision surgery.At the final review, 264 patients had died because of reasons unrelated to the procedures (mean 7.8±4.7years after the procedure), 48 were lost to follow-up (mean 3.0±3.3years after the procedure), and 39 patients (8%) had undergone acetabular revision of which 12 were for infection (2.5%), 25 were for loosening (5.4%) (5 femoral loosening only) and 2 were for dislocation (0.4%). In all, there were 10/466 dislocations (2.1%) of which 5/257 (1.9%) were in the primary group and 5/209 (2.4%) were in the revision group: 2 had a cup exchange and 8 were reduced by closed procedures. The probability of survival free of mechanical complications at 10years was estimated at 94.8%±1.6% (95% CI: 91.6%-98.0%) for the primary group and 87.8%±2.7% (95% CI: 82.4%-93.2%) for the revision groups (p=0.0017). There were 39 re-operations in the overall cohort: 1/257 (0.4%) for dislocation, 7/257 (2.7%) for aseptic loosening and 3/257 (1.2%) for infection in the primary group, while in the revision group, 1/209 (0.5%) was for dislocation, 18/209 (8.6%) for aseptic loosening and 9/209 (4.3%) for infection.The Lefèvre retentive cup has good long-term survival with a low mechanical complication rate, both in primary and revision surgery. To us, this implant appears to be a reliable salvage procedure for total hip replacement in patients at high risk for dislocation.IV; retrospective study without control group.

Lower-limb discrepancy following total hip arthroplasty is the third-most common reason for patient dissatisfaction in orthopaedic surgery. Therefore, accurate planning and evaluation methods are mandatory. The main aim of this study was to evaluate the reliability of the EOS™ system by establishing and comparing the reproducibility of lower-limb automatic and manual 3D measurements. We hypothesized that the reproducibility of the lower-limb measurements is similar regardless of the method used and with an agreement higher than 0.95 for the length parameters. This study utilized an EOS radiological database of 112 patients. Two independent observers performed two rounds of lower-limb measurements twice, either in manual 3D or automatic 3D mode. The intra- and inter-observer reproducibility was evaluated by the calculation of the intra-class coefficient for each measurement method. The methods were then compared. The intra- and inter-observer reproducibility for length measurements found with the manual and automatic 3D methods was always > 0.98. There was no significant difference in the reproducibility between the two measurement modes, with the exception of the offset, hip–knee–shaft, and neck–shaft angles. Our results indicate a very good reproducibility of EOS™ length measurement, regardless of the method used. Automated 3D mode is preferred for the collection of angular and offset measurements. Furthermore, manual mode measurements are not affected by surgical history. Level of evidence IV.

Background Constrained liners are used as part of a salvage procedure to provide stability for patients at high risk for dislocation after a total hip arthroplasty. However, no recent studies exist highlighting their effectiveness and/or limitations. Method This prospective review included 166 consecutive hip arthroplasties, either primary (27%) or revision (73%), with a unique design of a constrained liner: Lefevre retentive cup. There were 113 females (69%), and the average age at index surgery was 75.9 years (range, 35-94). The mean follow-up was 6.2 years (range, 0.3-11). Results Twenty patients had a reoperation; 10 for infection (4 acute and 6 chronic joint infection) and 10 for cup failure (5 fixation failure, 3 aseptic loosening, and 2 dislocation). Ten-year survivals for cup revision were 89% (CI, 83-94) and 92% (CI, 89-97) for all revision and revision for noninfectious reasons, respectively. When solely evaluating for dislocation, the survival at 10 years was 99% (CI, 97-100). Considering primary and revision cases, 10-year survivals cup revision for aseptic reasons were 92.4% (CI, 84-100) and 92.5% (CI, 87-98), respectively. Conclusions The Lefevre retentive cup demonstrated excellent 10-year’s survivorship. With the rate of aseptic loosening around 2% and a dislocation rate around 1%, the cup is as effective as other available devices and is therefore a cost-effective tool to reduce the risk of dislocation in at-risk patients undergoing hip arthroplasty.

To study the white matter tracts connecting the different stereoscopic visual areas of the brain by diffusion tensor imaging. In a previous study, we identified the cortical activations to a visual 3D stimulation in 12 subjects using functional MRI (fMRI). These areas of cortical activations [V5, V6, lateral occipital complex (LOC) and intra parietal sulcus areas (IPS)] in addition to the lateral geniculate nucleus (LGN) and the primary visual area V1 were chosen as regions of interest (ROIs). We studied by deterministic tractography the connections existing between these ROIs. Found connections were divided into three groups. The first group entails the geniculo-extrastriate connections. LGN was connected to V5, V6, IPS and LOC. These fibers course in the inferior longitudinal fascicule. The second group comprises the associative fibers. V1 was connected to V5 and LOC through the transverse occipital fascicule on one hand, and, to V6 and IPS through the stratum proprium cuni on the other hand. Connections between V5 and LOC, and V6 and IPS course within the vertical occipital fascicule. The third group contains commissural fibers. Forceps major entailed the connections between both V1, both V6, both IPS and IPS and contralateral V6. LGN was connected to contralateral LGN, V1, V6, IPS and LOC. We have elucidated numerous connections between the visual areas and the LGN. Generalization of these results to the remainder of the population must remain prudent due to the limited number of subjects in this study.

The hip center (HC) in Computer Assisted Orthopedic Surgery (CAOS) can be determined either with anatomical (AA) or functional approaches (FA). AA is considered as the reference while FA compute the hip center of rotation (CoR). Four main FA can be used in CAOS: the Gammage, Halvorsen, pivot, and least-moving point (LMP) methods. The goal of this paper is to evaluate and compare with an in-vitro experiment (a) the four main FA for the HC determination, and (b) the impact on the HKA. The experiment has been performed on six cadavers. A CAOS software application has been developed for the acquisitions of (a) the hip rotation motion, (b) the anatomical HC, and (c) the HKA angle. Two studies have been defined allowing (a) the evaluation of the precision and the accuracy of the four FA with respect to the AA, and (b) the impact on the HKA angle. For the pivot, LMP, Gammage and Halvorsen methods respectively: (1) the maximum precision reach 14.2, 22.8, 111.4 and 132.5 mm; (2) the maximum accuracy reach 23.6, 40.7, 176.6 and 130.3 mm; (3) the maximum error of the frontal HKA is 2.5°, 3.7°, 12.7° and 13.3°; and (4) the maximum error of the sagittal HKA is 2.3°, 4.3°, 5.9°, 6.1°. The pivot method is the most precise and accurate approach for the HC localization and the HKA computation.

Introduction L’arthroplastie totale de hanche est exposee a des complications notamment l’inegalite de longueur, source important de judiciarisation. La navigation permettrait d’optimiser la procedure mais son efficacite a gerer les longueurs de membre reste controversee. Aussi, nous avons mene une etude pour mesurer : – son interet pour atteindre les objectifs d’allongement et de lateralisation ; – sa fiabilite en evaluant la correlation des donnees radiologiques et de navigation ; – sa securite par l’analyse des complications specifiques et non specifiques a la navigation. Hypothese La navigation permet de gerer les longueurs de membres avec une erreur de 5 mm ou moins dans plus de 80 % des cas. Materiel et methodes Nous avons analyse retrospectivement une serie continue de 321 protheses totales de hanche sans ciment naviguees implantees par voie postero-laterale. Au recul minimal de 1 an, nous avons evalue l’atteinte des objectifs d’allongement et d’offset, la concordance donnees de navigation, donnees radiologiques et les incidents liees ou non a la navigation. En considerant l’hypothese de 80 % de patients ayant une inegalite de moins de 5 mm et en considerant l’hypothese nulle (PA = P0) avec alpha a 0,05, il fallait 200 observations avec une puissance de 90 %. Resultats Les objectifs d’allongement et de lateralisation ont ete respectes dans respectivement 83,3 et 88 % des cas. Vingt-deux patients ont necessite une compensation afin d’equilibrer une inegalite de longueur des membres inferieurs. La correlation entre les donnees radiologique et la navigation etait satisfaisante avec des coefficients de Pearson respectivement de 0,79 pour la longueur et 0,74 pour la lateralisation. Quarante-sept incidents (14,6 %) per- et postoperatoire specifiques (12,1 %) ou non (2,5 %) de la navigation ont ete observes. Conclusion Notre etude demontre un interet de la navigation quant a l’obtention des objectifs preoperatoires avec une bonne correlation des donnees navigation radios et sans incident majeur reporte.

Resume Introduction Les resultats des protheses totales de hanche (PTH) pour maladie luxante de hanche (MLH) sont connus mais pas l’influence des gestes conservateurs prealables sur la fonction et la survie de ces arthroplasties. En comparant deux groupes de PTH sur MLH, un avec geste osseux conservateur prealable (groupe AGO) et l’autre sans (groupe SGO), nos objectifs etaient de : (1) mesurer l’influence d’une chirurgie conservatrice prealable sur la fonction et la survie apres PTH, (2) preciser si un type particulier de geste conservateur avait une influence sur la survie ou la fonction. Hypothese La chirurgie conservatrice prealable de la MLH ne modifie ni la fonction ni la survie d’une arthroplastie ulterieure. Patients et methodes Cette etude retrospective cas-temoin multicentrique analysait 430 PTH sur MLH (332 patients, 269 femmes et 63 hommes âges en moyenne de 56 ans [17–80]) evaluees au recul moyen de 13,2 ans ± 5,4 (1–29). Le groupe AGO incluait 159 hanches (37 %) (64 gestes pelviens, 81 osteotomies femorales, 14 gestes combines pelviens et femoraux), et le groupe SGO incluait 271 hanches (63 %). Les deux groupes etaient comparables en termes de sexe, d’âge a l’intervention, de niveau d’activite evalue selon Devane, de score fonctionnel de Merle d’Aubigne preoperatoire, du type de MLH evalue radiographiquement selon Crowe. Resultats Au recul, les scores fonctionnels de Merle–d’Aubigne etaient comparables (16,8 ± 1,4 [11–18] groupe AGO versus 16,9 ± 1,5 [7–18] groupe SGO). Les taux de survie a 15 ans avec comme censure la reintervention pour changement d’un composant de la PTH toute cause confondue n’etaient pas significativement differents : 87 % (IC 95 % : 83–91 %) groupe AGO et 89 % (IC 95 % : 86–92 %) groupe SGO. A 10 ans pour le meme critere de censure, les survies n’etaient pas significativement differentes quel que soit le geste prealable effectue : 97 % (IC 95 % : 95–99 %) pour les PTH apres butees, 100 % apres osteotomie de Chiari, 95 % (IC 95 % : 92–98 %) apres osteotomie femorale, et 96 % (IC 95 % : 93–99 %) apres osteotomie de Milch. Discussion et conclusion Une chirurgie conservatrice dans le cadre de la MLH ne pejore ni le resultat fonctionnel ni la survie d’une arthroplastie ulterieure. Niveau de preuve III. Etude cas-temoin.

Although an early diagnosis is crucial to optimize outcomes after injury to the anterior cruciate ligament (ACL), little is known about the performance of emergency room physicians in diagnosing this injury.We hypothesized that emergency room physicians would miss a substantial proportion of ACL ruptures.: Prospective comparative study.From April 2004 through October 2004, all patients aged 15 to 55 years and presenting at the emergency department of a teaching hospital for acute knee injury without fracture or multiple injuries were included. The results of a standardized examination conducted by the emergency physicians were compared with the findings by a sports medicine specialist 5 +/- 2 days later. Magnetic resonance imaging was performed when the specialist found a positive Lachman's test and was used as the reference standard for diagnosing ACL rupture. Cohen's kappa test was used to evaluate agreement between emergency physicians and the specialist.Of the 79 included patients, 27 (34.2%) had a diagnosis of ACL rupture established by the specialist and confirmed by magnetic resonance imaging. Agreement was poor between emergency physicians and the sports medicine specialist regarding popping sound, instability, joint effusion, a positive Lachman's test, and a diagnosis of ACL rupture. Emergency physicians diagnosed only 7 of the 27 ACL ruptures.Emergency physicians missed a substantial proportion of acute ACL ruptures. Efforts are needed to improve their skills in diagnosing ACL rupture.

Some patients with grossly deficient soft-tissue attachments or neurologic impairment are often submitted to recurrent dislocation after total hip arthroplasty. This multifactorial complication is difficult to treat. For theses indications, we have developed a cemented constrained cup using a mobile retentive ring in a groove bellows the head equatorial plane. According to a retrospective series of 113 patients (40 for revision surgery and 73 for primary surgery) with 33.7 months of average clinical follow-up, we use this retentive cup to restore and maintain hip stability. This preliminary study needs to be continued for a longer period in order to obtain further information on development of radiolucent lines.

Introduction Malgre les bons resultats des arthroplasties totales de hanche, la luxation reste l’un des principaux risques postoperatoires de ces interventions. Parmi les differentes solutions envisagees pour reduire ces luxations, aucune n’a permis de les supprimer totalement. Nous avons donc evalue la survie a long terme du cotyle retentif de Lefevre, utilise comme moyen de reduction des luxations de prothese totale de hanche. Materiel et methodes La survie du cotyle retentif de Lefevre a ete analysee dans une serie monocentrique retrospective multioperateurs. L’âge, l’indication chirurgicale et l’utilisation d’un anneau de soutien cotyloidien ont ete utilises pour realiser des analyses en sous-groupe de cette survie concernant la luxation, le descellement, et la survie mecanique. Resultats Au total, 475 cas ont ete inclus dans la serie (412 analyses, 63 perdus de vue). Cinquante patients ont necessite une reintervention au niveau de la hanche operee : 23 pour descellement de cotyle, 10 pour luxation, 16 pour sepsis et une pour fracture de femur. La survie globale etait de 78,8 % a 15 ans (IC 95 % : 70,7–6,6 %). La survie mecanique a 15 ans dans le groupe premiere intention etait superieure (93,5 %) a celle du groupe reprise (78,5 %) (p = 0,004). Le temps de survie mecanique moyen etait de 16,2 ans pour les premieres intentions contre 14,7 ans pour les reprises. Discussion Les resultats de cette serie, compares a la litterature, retrouvent des taux de luxation comparables ou inferieures aux autres series de cotyle contraint, avec un taux de descellement lui aussi comparable. Malgre l’augmentation des contraintes liees a l’utilisation du cotyle retentif, les descellements etaient etales durant toute la duree de suivi, sans qu’il soit possible d’identifier un « delai » de survenue du descellement. Conclusion Le cotyle retentif de Lefevre presente dans notre serie un bon taux de survie a 15 ans. Le temps de survie moyen en premiere intention etait de 16 ans, autorisant l’usage de cette cupule chez les sujets âges, pouvant devenir par deficit cognitif ou neurologique a risque de luxation. Le taux de luxation dans les cas de reprise etait de 2,7 %, prouvant que ce type d’implant a un interet dans la prevention des luxations lors des reprises de prothese totale de hanche.

Introduction Constrained liners are used as part of a salvage procedure to provide stability for patients at high risk for dislocation following a total hip arthroplasty. However, no recent studies exist highlighting their effectiveness and or limitations. Method This prospective review included 166 consecutive hip arthroplasties, either primary (27%) or revision (73%), with a unique design of a constrained liner Lefevre retentive cup. There were 113 females (69%) and the average age at index surgery was 75.9 years (range 35–94). The mean follow-up was 6.2 years (range 0.3–11). Results Twenty patients had a reoperation ; 10 for infection (four acute and six chronic joint infection) and 10 for cup failure (five fixation-failure, three aseptic loosening and two dislocation). Ten-year survivals for cup revision were 89% (CI, 83–94) and 92% (CI, 89–97) for all revision and revision for non-infectious reasons respectively. When solely evaluating for dislocation, the survival at 10 years was 99% (CI, 97–100). Considering primary and revision cases, ten-year survivals cup revision for aseptic reasons were 92.4% (CI, 84–100) and 92.5% (CI, 87–98) respectively. Conclusions The Lefevre retentive cup demonstrated excellent ten-year's survivorship. With the rate of aseptic loosening around 2% and a dislocation rate around 1%, the cup is as effective as other available devices and is therefore, a cost-effective tool to reduce the risk of dislocation in at-risk patients undergoing hip arthroplasty.

International audience; Non-unions of greater trochanter (GT) fractures or osteotomies are the source of frequent complications. Two muscles are involved in the genesis of such non-unions, the gluteus medius and the gluteus minimus. Literature says that, during hip flexion, their terminal insertions on the faces of the GT generate an anterior translation of the GT responsible for contact loosening and healing defect. The main goal of this paper was to assess this hypothesis into the 3D space and to quantify the 3D displacements (three translations and three rotations) of the GT after trochanterotomy during passive motions of the hip joint (flexion, abduction-adduction, internal and external rotation). Therefore, we used 13 fresh cadaveric hips, on which we registered the GT displacements thanks to a 3D infrared localizer. An ultra low weight dynamic reference based has been developed to track the motion of the GT without any interference. The results have shown rotatory displacements of the GT around the three axes. This produces a posterior and lateral opening of the osteotomy site associated with a posterior rotatory shear of the GT. Above 45° of hip flexion these three rotations combine together to exert shear on the osteotomy site which is harmful to the osteosynthesis material and the consolidation potential and may explain implant loosening.

International audience; The risk of dislocation after THA reportedly is minimized if the acetabular implant is oriented at 45 degrees inclination and 15 degrees anteversion with respect to the anterior pelvic plane. This reference plane now is used in computer-assisted protocols. However, this static approach may lead to postoperative instability because the dynamic variations of the pelvis influence effective cup orientation and are not taken into account in this approach. We propose an ultrasound tool to register the preoperative dynamics of the pelvis for THA planning during computer-assisted surgery. To assess this pelvic behavior and its consequences on implant orientation, we tested a new 2.5-dimensional ultrasound-based approach. The pelvic flexion was registered in sitting, standing, and supine positions in 20 subjects. The mean values were -25.2 degrees +/- 5.8 degrees (standard deviation), 2.4 degrees +/- 5.1 degrees , and 6.8 degrees +/- 3.5 degrees , respectively. The mean functional anteversion varied by 26 degrees and the mean functional inclination by 12 degrees depending on the pelvic flexion. We therefore recommend including dynamic pelvic behavior to minimize dislocation risk. The notion of a safe zone should be revisited and extended to include changes with activity.

The aim of this paper is to assess the accuracy of an algorithm implemented by PRAXIM in the SURGETICS navigation station for detection of the hip center. This study will assess the robustness and accuracy of the algorithm in various clinical situations such as those involving non-sphericity of the femoral head, motion of the pelvis during hip center detection, and restricted range of motion.The localization of the hip center, based on kinematics, relies on the recording of n successive positions of the femoral rigid body in the localizer reference system during a passive circumduction motion of the hip joint. Therefore, the shape of the clouds of points acquired may vary from one acquisition to the next. To allow a comprehensive study of the consequences of these variations for hip center detection, we developed a simulator to generate numerous clouds of points. Results given subsequently for each test are the values of the difference between the femoral mechanical axis computed with C(c), the computed hip center, and the same axis computed with C(o), the reference hip center.Test 1: Sensitivity to noise. The errors ranged from 3.33 E - 12 (SD 3.29E - 12) for a noise of 0 mm to 8.18E - 1 (SD - 7.05E - 1) for a noise of 15 mm. Test 2: Sensitivity to the shape of the acquisition motion. All trajectories gave an error1 degrees . Test 3: Sensitivity to restricted range of motion. No value1 degrees was found during this test. Test 4: Sensitivity to the distance between two points of the cloud. No value0.5 degrees was found during this test. Test 5: Sensitivity to the number of points included in the cloud. No value1 degrees was found during this test.The Surgetics algorithm is robust to noise, can compensate for pelvic motion, and can be used even in the case of restricted range of motion.

Introduction Toute pathologie du pouce comme la rhizarthrose, peut compromettre la gestuelle de prehension. Nous rapportons nos resultats radio-cliniques de trapezectomies a plus de 5 ans de recul en insistant sur l’evaluation de cette prehension et de ses facteurs de mauvais resultats. Materiels et methodes Serie retrospective, continue, mono-operateur de 47 rhizarthroses (40 femmes et 7 hommes, âge moyen 59 ans) traitees par trapezectomie et stabilisation ligamentaire (32 petits palmaires et 15 hemi-grands palmaires), aucun geste sur la metacarpo-phalangienne (MCP). Interventions protegees par orthese, aucun brochage. Au recul, evaluation radio-clinique par un operateur independant (radiographie pouce face et profil). Nous insisterons sur l’hyperextension de la MCP, la fermeture commissurale et l’evaluation de la prehension (questionnaire d’evaluation de 5 prises d’utilisation quotidienne). La classification radiologique du GEM retrouve 23 stades 1, 9 stades 2 et 10 stades 4. l’index trapezien est calcule en pre et postoperatoire. Resultats 42 trapezectomies sont evaluees, delai moyen : 7,5 ans [5-11,5]. Delai moyen de consolidation : 7 mois [2-24]. 15 patients douloureux (EVA a 3 [1-6]) dont 13 ont un score d’Alnot a 1. Kapandji moyen a 9,6. Angle d’ouverture de M1 a 36,5°. Jamar moyen : 90 % [70 %-115 %] - Pinch : 76 % [56 %-100 %] (pourcentage/cote controlateral non opere). Une hyperextension de la MCP > a 20°chez 19 patients, statistiquement associee a la fermeture commissurale. Cette deformation pejore statistiquement la prehension, independamment du recul. L’analyse de ces patients permet de definir 2 groupes : avec hyperextension de la MCP > 20° en preoperatoire (10 patients), associee a une fermeture commissurale a 8 reprises. Deformation jamais ete corrigee apres chirurgie ; sans hyperextension preoperatoire (9 patients), associee a une fermeture commissurale a 2 reprises. En postoperatoire, ces patients presentent une hauteur trapezienne statistiquement plus faible (30 % contre 48 % de la hauteur initiale) et 6 ont une fermeture commissurale. Subjectivement, 40 patients sont satisfait ou tres satisfait et pret a refaire cette intervention. Discussion et conclusion L’originalite de notre etude est l’evaluation de la prehension mettant en evidence l’importance de l’hyperextension de la MCP et de la retraction commissurale postoperatoires sur son resultat. L’hyperextension superieure a 20° en preoperatoire fait discuter, un geste sur la MCP (retente capsulaire anterieure) associe a la trapezectomie. Une etude prospective evaluera les resultats de cette indication chirurgicale. Les autres mauvais resultat sont imprevisibles car la deformation apparait en postoperatoire, probablement liee au recul du premier metacarpien.

Si des modes d’osteosynthese par tuteurs intramedullaires ont ete imagines des le XIXe siecle, le veritable pere de l’enclouage centro-medullaire moderne realise a foyer ferme est sans conteste Gerard Kuntscher qui avait imagine toutes les evolutions et applications de la methode telle que nous la connaissons aujourd’hui. Le concept de tuteur metallique initialement concu pour le traitement des fractures diaphysaires du membre pelvien s’est rapidement developpe pour voir ses applications s’etendre a d’autres domaines grâce a l’amelioration de la technique, essentiellement par l’apport de l’alesage puis du verrouillage, sous l’influence de l’Ecole strasbourgeoise. En dehors du traitement des fractures recentes, la methode s’est averee aussi efficace pour le traitement des troubles de la consolidation, qu’il s’agisse de simples retards, de pseudarthroses ou de cals vicieux, ou encore pour le traitement curatif et preventif des lesions metastatiques des os longs. Suite aux bons resultats observes au niveau du membre pelvien, membre de charge et d’appui, la methode a ete appliquee au membre thoracique, membre libre, avec un succes comparable, grâce a l’utilisation du verrouillage. Tres rapidement, la philosophie de l’enclouage a evolue pour etre appliquee a la stabilisation des fractures epiphysaires (clous trochanteriens et supracondyliens du femur, clous epiphysaires proximaux de l’humerus, etc.). Dans cette nouvelle indication, le clou devient un tuteur intramedullaire servant de support pour une osteosynthese complementaire de l’epiphyse. Le dernier domaine d’application de la methode est la correction extemporanee d’anomalies d’axes, de longueurs ou de rotations des membres, grâce a l’utilisation d’une scie endomedullaire permettant une chirurgie a foyer ferme dont la rancon cicatricielle reste des plus limitees. En evitant les situations a risques et en respectant des regles techniques, on doit eviter les deux grandes complications que sont le syndrome de loges et l’embolie graisseuse. Compte tenu des bons resultats cliniques de la methode dans des indications variees, l’enclouage centromedullaire tient maintenant une place importante dans l’arsenal therapeutique du chirurgien orthopediste-traumatologue.

Introduction Un bilan radiographique initial interprete comme normal devant un poignet douloureux post-traumatique peut conduire a des erreurs diagnostiques sources de complications comme la pseudarthrose du scaphoide. Nous avons evalue l’interet d’une consultation specialisee systematique pour ces patients et l’apport diagnostic de la radioscintigraphie quantitative (RSQ). Materiels et Methodes Etude prospective, continue, mono-examinateur, d’avril a decembre 2006, incluant 105 patients (62 hommes, 43 femmes, âge moyen 38 ans), ayant presente un traumatisme du poignet unilateral, aucune fracture diagnostiquee aux urgences. A J+ 8 etait realise un examen clinique systematise du poignet avec relecture des radiographies initiales determinant 4 groupes de patients : 1. diagnostic radio-clinique de fracture evident, traitement : manchette ; 2. clinique evocatrice de fracture occulte : indication de RSQ ; 3. doute sur une pathologie ligamentaire : cliches dynamiques et/ou arthro-scanner ; 4. examen radio-clinique normal. Traitement des fractures occultes : manchette 5 semaines (scaphoide 2 mois), des contusions osseuses : orthese amovible 4 semaines. Evaluation radio-clinique et fonctionnelle (score de Dubert) par rapport au cote sain au dernier recul (6 semaines a 6 mois). REsultat Relecture des radiographies : 12 fractures. Sur 44 RSQ realisees : 86 % sont positives. On retrouve 27 fractures (7 scaphoides, 6 radius, 3 triquetrums, 3 pisiformes, 4 trapezes, 4 hamatums), 11 contusions osseuses (dont 3 scaphoides), 4 arthro-scanners demandes : une lesion scapho-lunaire (statique sur cliches dynamiques), une lesion du ligament triangulaire traitees orthopediquement. Evaluation radio-clinique des 39 fractures : consolidation osseuse : 100 %, une fracture occulte du scaphoide visualisee secondairement. Reprise de travail : 100 %, delai moyen 70 jours [5-115]. Trente-quatre patients avait une EVA = 0, et 5 patients une EVA 2 ou 1 lors d’efforts importants. La mobilite etait identique chez 36 patients. On observait une perte de 20° de flexion dorsale chez 3 patients. La force moyenne pinch et jamar etait de 94 et 92 % [80 %-100 %], le score de Dubert moyen de 3/150 [0-12]. La valeur predictive positive de fracture (VVPF) etait > a 75 % : œdeme de la tabatiere anatomique, douleur sur le tubercule de Lister, le tubercule du scaphoide et le pyramidal. Discussion et Conclusion Cette etude souligne l’interet de reevaluer tous les patients presentant un traumatisme du poignet (37 % avaient une lesion osseuse dont 25 % une authentique fracture occulte). Un examen clinique systematise, se basant essentiellement sur les 4 signes ayant une VPPF > a 75 %, permet de limiter les indications d’examen complementaire (seulement 14 % de RSQ normale). La RSQ permettant le diagnostic de fracture occulte et de contusion osseuse, s’integre maintenant dans notre nouvel arbre decisionnel de prise en charge systematique des traumatismes du poignet en attendant une meilleur accessibilite de l’IRM.