Optimization of components’ positioning in primary total hip arthroplasty

Optimisation du positionnement des implants lors d’arthroplastie totale de hanche primaire La prothèse totale de hanche est considérée comme l’une des plus importantes avancées médicales du XXème siècle. L’objectif de ce travail était d’étudier l’orientation anatomique des structures constituant l’articulation de la hanche et d’ensuite analyser la position des implants des prothèses totales de hanche afin d’améliorer l’implantation des composants prothétiques dans le but de réduire les phénomènes de luxation, usure, fracture et douleurs inhérents à cette chirurgie. Une étude de l’orientation anatomique du ligament transverse de l’acetabulum, du labrum et des cornes a été réalisée. Ensuite nous nous sommes intéressés au composant fémoral avec des études radiographique et tomodensitométriques de l’antéversion fémorale. Nous avons essayé de mesurer l’antéversion fémorale prothétique à partir d’une radiographie de face. Ensuite, nous avons démontré que le scanner était un moyen fiable pour localiser le centre de la tête du fémur en comparaison avec un système Motion Analysis et un bras Faro. Enfin, nous avons mesuré l’antéversion fémorale avant et après PTH ainsi que la situation du centre de tête fémorale avant et après arthroplastie. Le but était d’analyser la possibilité de reproduire, avec une tige prothétique droite, l’antéversion fémorale native. Des applications pratiques de mesure de l’amplitude de mouvement prothétique ont permis de connaître, dans des cas de luxation prothétique, si le positionnement des implants était le facteur causal. Une application clinique a montré qu’en cas de positionnement non optimal de l’implant acétabulaire, l’incidence des fractures d’insert céramique était augmentéeOptimization of components’ positioning in primary total hip arthroplasty Total hip arthroplasty is one of the most important innovations of the 20th century. The aim of this study was to evaluate the anatomical orientation of articular structures of the hip and then to analyze component’s positioning in order to improve the implantation of prosthetic components to minimize dislocation, wear, fracture and pain. The anatomical orientation of transverse acetabular ligament, labrum and horns was studied. Femoral component orientation was assessed with the help of X-rays and CT-scan. We measured femoral anteversion with AP X-rays. Then, we demonstrated that CT-scan was an accurate method to localize femoral head center in comparison with Motion Analysis and Faro. Femoral anteversion and femoral head center were assessed before and after surgery. The goal was to analyze the restoration of femoral anteversion after THA with a straight cementless stem. Some cases of THA dislocations were evaluated with measurement of prosthetic ROM. It allowed us to know whether implant positioning was the risk factor of dislocation. A clinical observation showed that in case of cup malpositioning, the rate of ceramic liner fractures increase

Optimisation du positionnement des implants lors d'arthroplastie totale de hanche primaire

Optimization of components’ positioning in primary total hip arthroplasty Total hip arthroplasty is one of the most important innovations of the 20th century. The aim of this study was to evaluate the anatomical orientation of articular structures of the hip and then to analyze component’s positioning in order to improve the implantation of prosthetic components to minimize dislocation, wear, fracture and pain. The anatomical orientation of transverse acetabular ligament, labrum and horns was studied. Femoral component orientation was assessed with the help of X-rays and CT-scan. We measured femoral anteversion with AP X-rays. Then, we demonstrated that CT-scan was an accurate method to localize femoral head center in comparison with Motion Analysis and Faro. Femoral anteversion and femoral head center were assessed before and after surgery. The goal was to analyze the restoration of femoral anteversion after THA with a straight cementless stem. Some cases of THA dislocations were evaluated with measurement of prosthetic ROM. It allowed us to know whether implant positioning was the risk factor of dislocation. A clinical observation showed that in case of cup malpositioning, the rate of ceramic liner fractures increased.Optimisation du positionnement des implants lors d’arthroplastie totale de hanche primaire La prothèse totale de hanche est considérée comme l’une des plus importantes avancées médicales du XXème siècle. L’objectif de ce travail était d’étudier l’orientation anatomique des structures constituant l’articulation de la hanche et d’ensuite analyser la position des implants des prothèses totales de hanche afin d’améliorer l’implantation des composants prothétiques dans le but de réduire les phénomènes de luxation, usure, fracture et douleurs inhérents à cette chirurgie. Une étude de l’orientation anatomique du ligament transverse de l’acetabulum, du labrum et des cornes a été réalisée. Ensuite nous nous sommes intéressés au composant fémoral avec des études radiographique et tomodensitométriques de l’antéversion fémorale. Nous avons essayé de mesurer l’antéversion fémorale prothétique à partir d’une radiographie de face. Ensuite, nous avons démontré que le scanner était un moyen fiable pour localiser le centre de la tête du fémur en comparaison avec un système Motion Analysis et un bras Faro. Enfin, nous avons mesuré l’antéversion fémorale avant et après PTH ainsi que la situation du centre de tête fémorale avant et après arthroplastie. Le but était d’analyser la possibilité de reproduire, avec une tige prothétique droite, l’antéversion fémorale native. Des applications pratiques de mesure de l’amplitude de mouvement prothétique ont permis de connaître, dans des cas de luxation prothétique, si le positionnement des implants était le facteur causal. Une application clinique a montré qu’en cas de positionnement non optimal de l’implant acétabulaire, l’incidence des fractures d’insert céramique était augmentée

Strain Assessment of Deep Fascia of the Thigh During Leg Movement: An in situ Study

Fascia is a fibrous connective tissue present all over the body. At the lower leg level, the deep fascia that is overlying muscles of the outer thigh and sheathing them (fascia lata) is involved in various pathologies. However, the understanding and quantification of the mechanisms involved in these sheathing effects are still unclear. The aim of this study is to observe and quantify the strain field of the fascia lata, including the iliotibial tract (ITT), during a passive movement of the knee. Three fresh post-mortem human subjects were studied. To measure hip and knee angles during knee flexion-extension, passive movements from 0° to around 120° were recorded with a motion analysis system and strain fields of the fascia were acquired using digital image correlation. Strains were computed for three areas of the fascia lata: anterior fascia, lateral fascia, and ITT. Mean principal strains showed different strain mechanisms depending on location on the fascia and knee angle. For anterior and lateral fascia, a tension mechanism was mainly observed with major strain greater than minor strain in absolute value. While for the ITT, two strain mechanisms were observed depending on knee movement: tension is observed when the knee is extended relatively to reference position of 47°, however pure shear can be observed when the knee is flexed. In some cases, minor strain can also be higher than major strain in absolute value, suggesting high tissue compression probably due to microstructural fiber rearrangements. This in situ study is the first attempt to quantify the superficial strain field of fascia lata during passive leg movement. The study presents some limitations but provides a step in understanding strain mechanism of the fascia lata during passive knee movement

Ruptures partielles du ligament croisé antérieur du genou (étude d'une série de 30 cas avec un recul minimum de 2 ans)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Periprosthetic osteolysis after AES total ankle replacement: Conventional radiography versus CT-scan

BACKGROUND: The aim of this study was to compare conventional X-rays and CT-scan in detecting peri-prosthetic osteolytic lesions, a major concern after total ankle replacement (TAR). METHODS: We prospectively assessed 50 patients (mean age 56 years), consecutively operated on by the same senior surgeon, between 2003 and 2006 and with a mean follow-up period of 4 years (range, 2-6.2). The component used was AES total ankle replacement. The etiologies for total ankle arthroplasty were: posttraumatic in 50%, osteoarthritis secondary to instability in 36%. Plain radiographs were analyzed by 4 independent observers, using a 10-zone protocol (location) and 5 size categories. RESULTS: At 4-year follow-up, all patients had been CT-scan assessed with the same protocol by 2 independent observers. Plain radiographs showed dramatic progression of severe periprosthetic lyses (>10mm): from 14% to 36% of interface cysts for the tibial component respectively at 2 and 4-year follow-up and from 4% to 30% for the talar implant. The talar component was more accurately assessed by CT-scan (mean frontal and sagittal talar lesion: from 270 mm2 to 288 mm2 for CT-scan versus 133 mm2 to 174 mm2 for X-rays). For tibial cysts, axial views showed larger lesions (313 mm2 than frontal (194 mm2) or sagittal (213.5 mm2) views. At 4-year follow-up, 24% of patients had revision with curetage or arthrodesis, and at 7 years follow-up 38% were revised. CONCLUSION: These results are similar to recent AES series, justifying withdrawal of this device. CT-scan was more accurate than X-rays for detecting and quantifying periprosthetic osteolysis. We recommend a yearly radiological control and CT-scan in case of lesion on X-rays

Cementless hydroxyapatite-coated stem with dual mobility and posterior approach in over-80 year-old patients with osteoarthritis: Rates of dislocation and periprosthetic fracture at a mean 8 years' follow-up

BACKGROUND: Straight cementless stems are common in primary total hip arthroplasty (THA) in the elderly, but controversial due to higher risk of loosening and periprosthetic fracture (PPF). Apart from registries, results for the Corail implant and dual mobility (DM) in over-80 years-old are not known, notably in case of systematic association to a DM cup. We therefore performed a retrospective analysis of Corail implants in patients aged?80years at implantation for osteoarthritis of the hip, assessing 1) PPF rate and survival for cementless straight stems associated to DM cups, 2) complications, and dislocation in particular, and 3) clinical scores.HYPOTHESIS: PPF and dislocation rates are low in THA with cementless straight stem associated to DM cup in patients aged?80years.PATIENTS METHODS: A retrospective study was conducted in our department for the period July 2007 to December 2012. Inclusion criteria were age?80years, with primary THA for osteoarthritis. Exclusion criteria were revision procedure and femoral neck fracture. One hundred and twenty-eight consecutive THAs were included, in 120 patients, with a minimum 5years' follow-up. Clinical results were assessed on Harris Hip Score (HHS) and Oxford Hip Score (OHS). Data were collected for PPF or dislocation and other complications.RESULTS: At a mean 8±1 years' follow-up (range, 5-10 years), 66 patients (55%, for 68 hips) were alive, 48 (40%, for 54 hips) had died, and 6 (5%, for 6 hips) were lost to follow-up. Median age at surgery was 83years (range, 80-93years). Mean OHS at last follow-up was 41±6 (range, 21-48) and HHS 83±14 (range, 23-100) with mean gain of 32 points (95% CI, [28-36];

Analysis of an explanted dual mobility cup after 21 years, parabolic wear pattern: A case report

Case: A dual mobility cup was implanted in 1983 in a 43-year woman. After 31 years of normal function, we analysed the explanted materials with modern techniques. Conclusion: Volumetric wears of the small and large articulations of the dual-mobility construct were similar. For the first time, we demonstrated that the dual-mobility liner underwent parabolic (not linear) wear during the period of implantation

Prospective longitudinal study of one hundred patients with total hip arthroplasty using a second-generation cementless dual-mobility cup

PURPOSE: The aim of our study was to assess the radio-clinical results, mid-term survivorship and dislocation rate of a new-generation dual-mobility cup. METHODS: The first 100 patients (104 primary total hip arthroplasties) who were implanted with a new-generation cementless dual-mobility cup (Sunfit TH, Serf, Décines) were included in our study, with a minimum follow-up of five years. RESULTS: Average follow-up was six years±0.44 (5-7). At last follow-up, the Harris and PMA scores were significantly improved, from 56 to 94 and 13 to 17 respectively (p<0.001). No radiolucent line could be observed. There were no cases of prosthetic or intraprosthetic dislocation in our series. Survivorship without cup loosening as the endpoint was 100 %. CONCLUSIONS: This study confirmed the interest of dual mobility in preventing prosthetic hip dislocation. Intraprosthetic dislocation is a complication that seems to have been resolved in the mid-term follow-up

Long-term survivorship of the Corail? standard stem

Introduction The Corail? stem, which was first introduced in 1986, has since been modified twice: first to make the neck thinner and then to change the location of the laser markings. The survival and complications of the first-generation straight, titanium, hydroxyapatite-coated stem are known; however, there is little specific information about the latest-generation stem. This led us to conduct a retrospective study to determine the: (1) long-term survival; (2) clinical and radiographic outcomes; (3) complications; and (4) risk factors for revision of the newest Corail? stem. Hypothesis The newest Corail? AMT (Articul/EZE? Mini Taper) standard stem has comparable survival to prior models. Patients and methods This single-center, retrospective study included 133 patients (140 hips), who underwent primary total hip arthroplasty (THA), between January and December 2004, in which a Corail? Standard stem was implanted using a posterolateral approach. Patients who underwent revision THA, THA due to femoral neck fracture or who received lateralized (offset) stems were excluded. The mean age at the time of THA was 69±13 years [35-92] in 85 men (61%) and 55 women (39%) who had a mean BMI of 27kg/m2±11 [16-39]. At the latest follow-up, 32 patients (32 hips) had died and 8 patients (8 hips) had less than 3 years' follow-up, thus were not included in the clinical evaluation. The Merle d'Aubigné (PMA) score was collected. The stem's survivorship was calculated using the Kaplan-Meier method with revision for aseptic loosening and revision or implant removal for any reason as the end-points. The Cox model was used to analyze risk factors for revision. The mean follow-up was 10±3 years [3-12]. Results The PMA score was 12±2.6 [5-17] preoperatively and 16±2.7 [7-18] at the last follow-up (