Time filter

Source Type

Boyer B.,Chirurgie Orthopedique et Traumatologie | Philippot R.,Laboratoire Of Physiologie Of Lexercice | Geringer J.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Farizon F.,Laboratoire Of Physiologie Of Lexercice
International Orthopaedics | Year: 2012

Purpose: The longest follow-up dual mobility series from inventor Gilles Bousquet focussing on implant survival and the incidence of dislocation. Methods: This was a retrospective study from 1985 to 1990, on 240 hips using a PF® modular femoral stem and a dual mobility Novae® tripodal socket (SERF). Results: The 22-year follow-up global survival rate was 74%. No dislocation occurred, 41 hips were revised, including ten retentive failures (RF), 12 hips were lost to follow-up, 87 patients (99 hips) died without revision, and 90 hips were still in situ. Conclusion: The dual mobility socket global survival rate is comparable to similar series. The 0% dislocation rate demonstrates the success of dual mobility with regard to implant stability. The main issues were cup fixation, which might be improved by the use of macrostructures and HA coating, and osteolytic lesions, caused by polyethylene wear. Traditionally suitable for patients older than 60 years, dual mobility might be extended for use in patients over 50. © 2011 Springer-Verlag.


Philippot R.,Laboratoire Of Physiologie Of Lexercice | Philippot R.,Jean Monnet University | Philippot R.,North Hospital | Boyer B.,Jean Monnet University | And 6 more authors.
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2012

Purpose: The influence of the medial patellar ligamentous structures on patellar tracking has rarely been studied. Thus the main purpose of this cadaveric biomechanical study was to determine the influence of the medial patellofemoral (MPFL), medial patellomeniscal (MPML) and medial patellotibial (MPTL) ligaments on the three-dimensional patellar tracking during knee flexion. This study was conducted using a validated cadaveric optoelectronic protocol for analysis of patellar kinematics. Methods: For each cadaveric knee study, four successive acquisitions were performed; first was studied patellar tracking in healthy knees, then the junction between MPFL and vastus medialis obliquus (VMO) was sectioned, the MPFL was released at its patellar attachment and finally was released the insertion of the MPML and MPTL. Results: In this study, the MPFL accounts for 50-60% of the medial stabilization forces of the lateral patellar shift during patellar engagement in the femoral trochlea. This work confirm and clarify the role of the MPFL as the primary stabilizer of the patella during the initial 30° of knee flexion. Moreover, this study shows no significant results regarding the stabilizing action of the VMO on the patella during knee flexion. Conclusion: This in vitro study, conducted with an experimental protocol previously validated in the literature, helps quantify the actions of the MPFL, the VMO, and the MPML/MPTL respectively, and identify areas of joint motion where these structures have the most significant influence. This confirms the importance of reconstruction in the treatment of chronic patellar instability. During its reconstruction, care should be taken to adjust the MPFL balance during the initial 20°-30° of flexion. © 2011 Springer-Verlag.


Philippot R.,Laboratoire Of Physiologie Of Lexercice | Philippot R.,Jean Monnet University | Boyer B.,Laboratoire Of Physiologie Of Lexercice | Boyer B.,Jean Monnet University | And 8 more authors.
Clinical Biomechanics | Year: 2012

Background: Medial patellofemoral ligament reconstruction is currently the technique of choice for the treatment of patellar instability. But what should be the most appropriate graft tension for optimal restoration of patellofemoral kinematics? Methods: Six freshly frozen cadaveric knees were studied, the three bone segments were respectively equipped with opto-reflective markers. The acquisitions were made using the Motion Analysis System®. Six successive acquisitions were performed for each knee under different levels of graft tension. Findings: With an intact medial patellofemoral ligament, the medial patellar tilt increased up to a mean value of 2.02° (SD 3.1), the medial patellar translation gradually increased up to a mean value of 3.3 mm (SD 2.25) with a slight lateral rotation over the first 30° of knee flexion with a maximum mean value of 1.22° (SD 0.8) at 20° of knee flexion. Reconstruction of the medial patellofemoral ligament was performed using different levels of tension applied to the graft. Only 10 N of graft tension could restore normal patellar tilt, lateral shift and rotation, with results approximating those measured on healthy knee. Interpretation: This study confirms the role of the medial patellofemoral ligament in providing adequate patellar stability during the first 30° of knee flexion. According to our findings, a 10 N tension applied to the graft appears sufficient to ensure proper control of patellar tracking whereas 20, 30 and 40 N of tension are excessive tension values inducing a major overcorrection in all studied parameters. © 2011 Elsevier Ltd. All rights reserved.


Terrier R.,Laboratoire Of Physiologie Of Lexercice | Terrier R.,University of Savoy | Rose-Dulcina K.,University of Savoy | Toschi B.,University of Savoy | Forestier N.,University of Savoy
Clinical Biomechanics | Year: 2014

Background Previous studies have proposed that evertor muscle weakness represents an important factor affecting chronic ankle instability. For research purposes, ankle evertor strength is assessed by means of isokinetic evaluations. However, this methodology is constraining for daily clinical use. The present study proposes to assess ankle evertor muscle weakness using a new procedure, one that is easily accessible for rehabilitation specialists. To do so, we compared weight bearing ankle inversion control between patients suffering from chronic ankle instability and healthy subjects. Methods 12 healthy subjects and 11 patients suffering from chronic ankle instability conducted repetitions of one leg weight bearing ankle inversion on a specific ankle destabilization device equipped with a gyroscope. Ankle inversion control was performed by means of an eccentric recruitment of evertor muscles. Instructions were to perform, as slow as possible, the ankle inversion while resisting against full body weight applied on the tested ankle. Results Data clearly showed higher angular inversion velocity peaks in patients suffering from chronic ankle instability. This illustrates an impaired control of weight bearing ankle inversion and, by extension, an eccentric weakness of evertor muscles. Interpretation The present study supports the hypothesis of a link between the decrease of ankle joint stability and evertor muscle weakness. Moreover, it appears that the new parameter is of use in a clinical setting. © 2014 Elsevier Ltd.


Ngo K.T.A.,Jean Monnet University | Ngo K.T.A.,Laboratoire Of Physiologie Of Lexercice | Denis C.,Jean Monnet University | Denis C.,Laboratoire Of Physiologie Of Lexercice | And 4 more authors.
Acta Physiologica | Year: 2012

Aim: Endurance and resistance training (ET and RT, respectively) in older subjects have been proven beneficial against metabolic or cardiovascular disorders and against sarcopaenia respectively. Like ET, RT may also increase muscle oxidative capacities. In addition, it could be questioned whether RT, similarly to ET, is able to increase muscle energetic stores such as intra-myocellular lipids (IMCL) and glycogen contents. To evaluate a possible ET- and RT-induced parallel increase in oxidative capacity and energetic stores, active elderly men (72±2years) were submitted to a 14-week training programme (three times week -1) combining lower body endurance and upper body resistance. Methods: Muscle samples were collected in ET vastus lateralis (VLat) and RT deltoid (Del) muscles before and after training. IMCL and glycogen contents were assessed by histochemistry (Oil Red O and periodic acid-Schiff staining, respectively) and by biochemical assay for glycogen. Citrate synthase (CS, marker of mitochondrial citric acid cycle), β-hydroxyacyl coenzyme A dehydrogenase (β-HAD, beta-oxidation) and phosphofructokinase (PFK, glycolytic pathway) activities were determined and so was the capillary interface index (LC/PF). Results: Both training regimens significantly increased CS and LC/PF in ET-VLat and RT-Del. IMCL content and β-HAD activity increased (P<0.05) only in ET-VLat, whereas PFK activity increased (P<0.05) only in RT-Del. Glycogen content was not significantly altered in response to training in both muscles. Conclusion: Unlike RT, which induced an increase in PFK, ET is able to increase IMCL content and β-oxidation capacity in active elderly men, even though both training may improve CS activity and LC/PF. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.


Philippot R.,Laboratoire Of Physiologie Of Lexercice | Philippot R.,Jean Monnet University | Chouteau J.,University of Lyon | Testa R.,University of Lyon | Moyen B.,University of Lyon
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2010

Opto-electronic cinematic analysis has already proven useful in the investigation of patients with a knee replacement; however, neither patellar tracking nor the various positional parameters relevant to instability such as patellar tilt and/or patellar shift have ever been specifically evaluated using this type of system. The aim of this research was to validate the relevance of this type of cinematic analysis in order to use it in the evaluation of the main factors underlying patellar instability. Six fresh-frozen anatomical specimens were studied. The data were acquired using the Motion Analysis® system. Statistical analysis reveals a good reproducibility of measurements. Our protocol based on an opto-electronic acquisition system has an accuracy of 0.23 mm for shift and of 0.4° for rotation, which is calculated by integrating the various experimental parameters and instrumental features specific to the Motion Analysis® system. The results are consistent with published results which further attests to the validity and the efficacy of the protocol and encourages us that this protocol is suitable for the in vitro study of patellar kinematics. © 2009 Springer-Verlag.


Busso T.,Jean Monnet University | Busso T.,Laboratoire Of Physiologie Of Lexercice | Fluck M.,Manchester Metropolitan University
European Journal of Applied Physiology | Year: 2013

Altered expression of a broad range of gene transcripts after exercise reflects the specific adjustment of skeletal muscle makeup to endurance training. Towards a quantitative understanding of this molecular regulation, we aimed to build a mixed-effects model of the dynamics of co-related transcript responses to exercise. It was built on the assumption that transcript levels after exercise varied because of changes in the balance between transcript synthesis and degradation. It was applied to microarray data of 231 gene transcripts in vastus lateralis muscle of six subjects 1, 8 and 24 h after endurance exercise and 6-week training on a stationary bicycle. Cluster analysis was used to select groups of transcripts having highest co-correlation of their expression (r > 0.70): Group 1 comprised 45 transcripts including factors defining the oxidative and contractile phenotype and Group 2 included 39 transcripts mainly defined by factors found at the cell periphery and the extracellular space. Data from six subjects were pooled to filter experimental noise. The model fitted satisfactorily the responses of Group 1 (r 2 = 0.62 before and 0.85 after training, P < 0.001) and Group 2 (r 2 = 0.75 and 0.79, P < 0.001). Predicted variation in transcription rate induced by exercise yielded a difference in amplitude and time-to-peak response of gene transcripts between the two groups before training and with training in Group 2. The findings illustrate that a mixed-effects model of transcript responses to exercise is suitable to explore the regulation of muscle plasticity by training at the transcriptional level and indicate critical experiments needed to consolidate model parameters empirically. © 2012 Springer-Verlag Berlin Heidelberg.


Neri T.,Service dorthopedie et traumatologie hOpital Nord | Philippot R.,Service dorthopedie et traumatologie hOpital Nord | Philippot R.,Laboratoire Of Physiologie Of Lexercice | Carnesecchi O.,Service dorthopedie et traumatologie hOpital Nord | And 2 more authors.
Orthopaedics and Traumatology: Surgery and Research | Year: 2015

Introduction: Among the numerous techniques available, medial patellofemoral ligament (MPFL) reconstruction is increasingly used for the surgical treatment of objective patellar instability. The main objective of the present study was to assess efficacy in preventing recurrence of patellar dislocation and in correcting radiographic patellar tilt. The study hypothesis was that MPFL reconstruction, isolated or with associated bone surgery, by restoring "favorable" graft anisometry, provides a good trade-off between patellar stability and absence of postoperative stiffness. Materials and methods: Eighty-seven patients (90 reconstructions) presenting with objective patellar instability were prospectively included. The standardized procedure comprised MPFL reconstruction using the gracilis tendon. Femoral fixation used an interference screw in a blind tunnel between the adductor magnus tubercle and the medial epicondyle; patellar fixation used 2 anchors. Complementary distal bone graft was associated in 21 patients due to a preoperative tibial tubercle-trochlear groove (TT-TG) distance exceeding 20. mm or to patella alta. Functional IKDC and Kujala scores and radiographic measurement of patellar tilt and femoral tunnel position were assessed preoperatively and at end of follow-up. Results: Mean follow-up was 24.3. months (range, 6-49. months). Three patients showed recurrence of patellar dislocation. Mean Kujala score rose from 53.88 preoperatively to 86.24 postoperatively, and mean real IKDC score from 45.15 to 73.92 (P<. 0.001). Patellar tilt decreased significantly between pre- and postoperative X-ray (P<. 0.001). Discussion: MPFL gracilis reconstruction provides good clinical results and good radiologic correction of patellar tilt, making it a technique of choice in the treatment of objective patellar instability. Level of evidence: Level IV. Retrospective case series study. © 2014 Elsevier Masson SAS.


PubMed | Center hospitalier du Forez, Laboratoire Of Physiologie Of Lexercice and Service dorthopedie et traumatologie
Type: Journal Article | Journal: Orthopaedics & traumatology, surgery & research : OTSR | Year: 2016

Patellar instability is a frequent cause of total knee arthroplasty (TKA) failure. In cases of post-arthroplasty patellar instability, the medial structures may be damaged. The objective of this study was to study the effectiveness of medial patellofemoral ligament (MPFL) reconstruction. We hypothesized that MPFL reconstruction will effectively realign the patella, making it a viable treatment option for managing post-arthroplasty patellar instability.In this retrospective study of six patients treated by four different surgeons, patients were included if they had a recurring or permanent patellar dislocation after undergoing TKA. Patients were excluded if the patellar instability was painful but did not result in dislocation. Each patient underwent MPFL reconstruction using the gracilis; additional procedures could be performed depending on the diagnosis. One patient required TKA revision because of an abnormally rotated femoral implant. The main outcome measure was the non-recurrence of the dislocation. The IKDC and Kujala functional scores, joint range of motion and patellar tilt on X-rays were analyzed preoperatively and at the last follow-up.At a mean follow-up of 23 months (6-46), none of the patients experienced a recurrence of the patellar dislocation. Only one patient had no improvements in the functional outcome scores. The patellar tilt was reduced in all patients.MPFL reconstruction-in isolation or with femoral component revision-is effective at treating post-arthroplasty patellar instability. It has its place in the treatment of patellar dislocation following TKA and its indications must be based on exact analysis of the reasons for the instability.IV-Retrospective cohort study.


PubMed | Laboratoire Of Physiologie Of Lexercice
Type: Journal Article | Journal: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA | Year: 2012

The influence of the medial patellar ligamentous structures on patellar tracking has rarely been studied. Thus the main purpose of this cadaveric biomechanical study was to determine the influence of the medial patellofemoral (MPFL), medial patellomeniscal (MPML) and medial patellotibial (MPTL) ligaments on the three-dimensional patellar tracking during knee flexion. This study was conducted using a validated cadaveric optoelectronic protocol for analysis of patellar kinematics.For each cadaveric knee study, four successive acquisitions were performed; first was studied patellar tracking in healthy knees, then the junction between MPFL and vastus medialis obliquus (VMO) was sectioned, the MPFL was released at its patellar attachment and finally was released the insertion of the MPML and MPTL.In this study, the MPFL accounts for 50-60% of the medial stabilization forces of the lateral patellar shift during patellar engagement in the femoral trochlea. This work confirm and clarify the role of the MPFL as the primary stabilizer of the patella during the initial 30 of knee flexion. Moreover, this study shows no significant results regarding the stabilizing action of the VMO on the patella during knee flexion.This in vitro study, conducted with an experimental protocol previously validated in the literature, helps quantify the actions of the MPFL, the VMO, and the MPML/MPTL respectively, and identify areas of joint motion where these structures have the most significant influence. This confirms the importance of reconstruction in the treatment of chronic patellar instability. During its reconstruction, care should be taken to adjust the MPFL balance during the initial 20-30 of flexion.

Loading Laboratoire Of Physiologie Of Lexercice collaborators
Loading Laboratoire Of Physiologie Of Lexercice collaborators