Prothèse totale de la hanche par voie antérieure "mini-invasive" [Total hip arthroplasty through anterior "minimal invasive" approach].

Total hip replacement has seen a tremendous development and has become one of the most successful surgical interventions in orthopaedics. While during the first decades of development of total hip arthroplasty the fixation of the implant into the bone was the main concern, the focus has shifted towards surgical technique and soft tissue handling. In order to avoid permanent soft tissue damage, muscular dysfunction and concerns in regards to cosmetics, minimal invasive and anatomic approaches have been developed. We here provide a short overview on various methods of total hip replacements and we describe our technique through a minimal invasive direct anterior approach. While muscle and nerve damage is minimal, this technique allows for a rapid rehabilitation and is associated with an excellent functional outcome and a minimal risk for dislocation.

Comparisons of Preoperative Three-Dimensional Planning and Surgical Reconstruction in Primary Cementless Total Hip Arthroplasty

La planification scanographique (3D) a démontré son utilité pour une reconstruction anatomique plus précise de la hanche (longueur du fémur, centre de rotation, offset, antéversion et rétroversion). Des études ont montré que lors de la planification 2D 50% seulement correspondaient à l'implant définitif du fémur alors que dans une autre étude ce taux s'élevait à 94% pour une planification 3D. Les erreurs étaient liées à l'agrandissement des radiographies. L'erreur sur la taille de la tige est liée à l'estimation inadéquate de la morphologie osseuse ainsi qu'à la densité osseuse. L'erreur de l'antéversion, augmentée par l'inclinaison du bassin, a pu être éliminée par la planification 3D et l'offset restauré dans 98%. Cette étude est basée sur une nouvelle technique de planification scanographique en trois dimensions pour une meilleure précision de la reconstruction de la hanche. Le but de cette étude est de comparer l'anatomie post-opératoire à celle préopératoire en comparant les tailles d'implant prévu lors de la planification 3D à celle réellement utilisée lors de l'opération afin de déterminer l'exactitude de la restauration anatomique avec étude des différents paramètres (centre de rotation, densité osseuse, L'offset fémoral, rotations des implants, longueur du membre) à l'aide du Logiciel HIP-PLAN (Symbios) avec évaluation de la reproductibilité de notre planification 3D dans une série prospective de 50 patients subissant une prothèse totale de hanche non cimentée primaire par voie antérieure. La planification pré-opératoire a été comparée à un CTscan postopératoire par fusion d'images. CONCLUSION ET PRESPECTIVE Les résultats obtenus sont les suivants : La taille de l'implant a été prédit correctement dans 100% des tiges, 94% des cupules et 88% des têtes (longueur). La différence entre le prévu et la longueur de la jambe postopératoire était de 0,3+2,3 mm. Les valeurs de décalage global, antéversion fémorale, inclinaison et antéversion de la cupule étaient 1,4 mm ± 3,1, 0,6 ± 3,3 0 -0,4 0 ± 5 et 6,9 ° ± 11,4, respectivement. Cette planification permet de prévoir la taille de l'implant précis. Position de la tige et de l'inclinaison de la cupule sont exactement reproductible. La planification scanographique préopératoire 3D permet une évaluation précise de l'anatomie individuelle des patients subissant une prothèse totale de hanche. La prédiction de la taille de l'implant est fiable et la précision du positionnement de la tige est excellente. Toutefois, aucun avantage n'est observée en termes d'orientation de la cupule par rapport aux études impliquant une planification 2D ou la navigation. De plus amples recherches comparant les différentes techniques de planification pré-opératoire à la navigation sont nécessaire.

Combining clinical factors and quantitative ultrasound improves the detection of women both at low and high risk for hip fracture.

We hypothesized that combining clinical risk factors (CRF) with the heel stiffness index (SI) measured via quantitative ultrasound (QUS) would improve the detection of women both at low and high risk for hip fracture. Categorizing women by risk score improved the specificity of detection to 42.4%, versus 33.8% using CRF alone and 38.4% using the SI alone. This combined CRF-SI score could be used wherever and whenever DXA is not readily accessible. INTRODUCTION AND HYPOTHESIS: Several strategies have been proposed to identify women at high risk for osteoporosis-related fractures; we wanted to investigate whether combining clinical risk factors (CRF) and heel QUS parameters could provide a more accurate tool to identify women at both low and high risk for hip fracture than either CRF or QUS alone. METHODS: We pooled two Caucasian cohorts, EPIDOS and SEMOF, into a large database named "EPISEM", in which 12,064 women, 70 to 100 years old, were analyzed. Amongst all the CRF available in EPISEM, we used only the ones which were statistically significant in a Cox multivariate model. Then, we constructed a risk score, by combining the QUS-derived heel stiffness index (SI) and the following seven CRF: patient age, body mass index (BMI), fracture history, fall history, diabetes history, chair-test results, and past estrogen treatment. RESULTS: Using the composite SI-CRF score, 42% of the women who did not report a hip fracture were found to be at low risk at baseline, and 57% of those who subsequently sustained a fracture were at high risk. Using the SI alone, corresponding percentages were 38% and 52%; using CRF alone, 34% and 53%. The number of subjects in the intermediate group was reduced from 5,400 (including 112 hip fractures) and 5,032 (including 111 hip fractures) to 4,549 (including 100 including fractures) for the CRF and QUS alone versus the combination score. CONCLUSIONS: Combining clinical risk factors to heel bone ultrasound appears to correctly identify more women at low risk for hip fracture than either the stiffness index or the CRF alone; it improves the detection of women both at low and high risk.

Diagnosis of periprosthetic hip infection : review

Since its introduction, total hip arthroplasty has become one of the most successful orthopedic operations ever. However, periprosthetic infection, now reported with the prevalence of around 1-2% is the most challenging complication. It is associated with disasterous physiological, psychological and financial effects. Therefore, early firm diagnosis is essential to avoid further patient morbidity and mortality as well as overwhelming financial medical service costs. This article reviews our current understanding of periprosthetic infection with particular focus on the clinical usefulness of various tests which are used to help make the diagnosis.

A propos des "small area variations": opérations pour fracture de hanche dans le canton de Vaud. [Small area variations: surgery for hip fractures in the canton of Vaud].

OBJECTIVES: Studies of small area variations of health care utilization are more and more frequent. Such variations are often considered to be an indication of variations in the quality of medical care. The variations in the rate of operations for hip fractures are among the lowest studied to date, due to the fact that a consensus exists concerning this surgery. Our objective is to examine these variations within the context of relatively small and heterogeneous districts. METHOD: Based on anonymous computerized data on public hospital stays, this study describes the variations in population rates (crude and standardized) of operations for hip fracture among the health districts of the Canton of Vaud for the period from 1986 to 1991. District populations vary from 22,000 to 164,000. Using the extremal quotient (EQ), the importance of these variations was determined. RESULTS: The study population consists of 2363 cases, of which 78% are women. Mean age is 80.4 for women and 70.6 for men. Standardized rates of operation for hip fracture per 100,000 in the Canton Vaud for the years 1986 to 1991 are, respectively: 56; 67; 86; 91; 89 and 94. The EQ for the years 1986 to 1991 are respectively: 8.2; 4.0; 3.5; 2.7; 1.9 and 1.9. The high EQ, especially for the earlier years, are contrary to the initial premise of absence of variation. The progressive implementation in the Canton Vaud of VESKA medical statistics could play a role, as could the small size of many of the districts, with resultant instability of rates. CONCLUSIONS: Considering the wide variations shown here for an operation hardly regarded as subject to variations, it is important to exercise caution in interpreting published data of small area variations.

Cable fixation and early total hip arthroplasty in the treatment of acetabular fractures in elderly patients.

Eighteen patients with acetabular fractures, with a mean age of 76 years, were treated with cable fixation and acute total hip arthroplasty. Nine were T-shaped fractures, 4 associated transverse and posterior wall, 2 transverse, 2 posterior column and posterior wall, and 1 anterior and posterior hemitransverse fractures. One patient experienced 3 episodes of hip dislocation within 10 months after surgery. All the others had a good outcome at a mean follow-up time of 36 months. Radiographic assessment showed healing of the fracture and a satisfactory alignment of the cup without loosening. This option provides good primary fixation, stabilizes complex acetabular fractures in elderly patients, and permits early postoperative mobilization.

FM127: Systemic metal ion levels in patients with modular neck total hip arthroplasties: a prospective cohort study

There is increasing evidence that modular neck stems are prone to corrosion-related complications. Recent studies showed elevated metal ions levels and occasional pseudotumor formation in patients with such implants. The purpose of this study was to compare systemic metal-ion levels in patients after primary THA with modular neck stems to those of patients after non-modular implants. To our knowledge, this is the first cohort study including a control group, THA without CoCr heads and dry-assembled neck-stem connections. Methods: 50 patients after THA at a minimum follow-up of 1 year have been selected for the study. Patients with multiple prosthesis or other implants have been deselected. All received a cementless SPS stem from Symbios (Ti6Al4V). 40 patients have the modular neck (CoCr) version and 10 a monobloc version. All bearings were either ceramic-ceramic or ceramic-polyethylene to minimize other sources of CoCr ion release. In the modular group, the neck was chosen pre-operatively based on a 3D planning, allowing for a dry assembly of the stem and neck on the back table before implantation. A plasma system coupled to mass spectrometry was used for a complete elementary quantification in blood and serum separately. Clinical outcome was measured using the Oxford Hip Score. Results : Complete data sets of 29 patients (24 in the modular neck-group (10male, mean age 63y, 35-84y) and 5 in the monobloc-group (3 male, 69 y, 51-83y) are available to date. Mean Co blood levels were .95 ug/L (.14-12.4) in the modular group vs .27 ug/L (.10-.73) in the monobloc group (p=.2). Respective values for Cr were significantly higher in the modular group (.99 g/L; range .75-1.21) compared to those in the monobloc group (.74 g/L ;.62-.86; p=.001). No significant difference was found when comparing serum levels. 5/24 patients had Co levels above 1 g/L (12/24 for Cr), which is by some considered as a relevant elevation. The maximum Co level was measured in an asymptomatic patient. The Oxford Hip Scores were similar in both groups. Conclusion: Cr levels were significantly elevated in the modular neck group compared to those in the monobloc group. 1/24 patients with a modular prosthesis exhibited Co levels, which are beyond the threshold accepted even for metal-on-metal bearing couples. These results have contributed to our decision to abandon the use of modular neck stems. Routine follow-up including annual measurements of systemic CoCr concentrations should be considered.

Fatal intrahepatic hemorrhage after nadroparin use for total hip arthroplasty.

Low-molecular-weight heparins have become the predominant choice for deep venous thrombosis prophylaxis and treatment. However, their use may cause bleeding complications. Intrahepatic bleeding is exceptional and only very few cases have been described. The authors present a unique case of fatal intrahepatic hematoma complicating nadroparin use in a 65-year-old woman with a hepatic cyst who was admitted to hospital for unilateral total hip arthroplasty. At autopsy, hemoperitoneum (2,000 ml of blood and clots) was evident. A ruptured sub-capsular hematoma involving the right lobe of the liver was observed. The hemorrhage within the cyst induced by the nadroparin use was likely responsible for the subsequent hepatic hematoma, liver rupture, and death. This case highlights the need for pathologists and surgeons to be aware of the possibility of intrahepatic hematoma in patients who have received low-molecular-weight heparins, undergone major surgery and present postoperative hemodynamic instability, especially in those with preoperative diagnosis of hepatic cyst.

Total hip replacement with a collarless polished cemented anatomic stem: clinical and gait analysis results at ten years follow-up.

PURPOSE: The aim of this study was to determine outcomes of total hip replacement (THR) with the Lemania cemented femoral stem. METHODS: A total of 78 THR patients were followed and compared to 17 "fit", healthy, elderly and 72 "frail" elderly subjects without THR, using clinical outcome measures and a portable, in-field gait analysis device at five and ten years follow-up. RESULTS: Forty-one patients (53%), mean age 83.4 years, available at ten years follow-up, reported very good to excellent satisfaction. Mean Harris Hip and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were 81.2 and 10.5 points, respectively, with excellent radiological preservation of proximal femur bone stock. Spatial and temporal gait parameters were close to the fit group and better than the frail group. CONCLUSIONS: Lemania THR demonstrated very good, stable clinical and radiological results at ten years in an older patient group, comparable to other cemented systems for primary THR. Gait analysis confirmed good walking performance in a real-life environment.

A genome-wide screen for interactions reveals a new locus on 4p15 modifying the effect of waist-to-hip ratio on total cholesterol.

Recent genome-wide association (GWA) studies described 95 loci controlling serum lipid levels. These common variants explain ∼25% of the heritability of the phenotypes. To date, no unbiased screen for gene-environment interactions for circulating lipids has been reported. We screened for variants that modify the relationship between known epidemiological risk factors and circulating lipid levels in a meta-analysis of genome-wide association (GWA) data from 18 population-based cohorts with European ancestry (maximum N = 32,225). We collected 8 further cohorts (N = 17,102) for replication, and rs6448771 on 4p15 demonstrated genome-wide significant interaction with waist-to-hip-ratio (WHR) on total cholesterol (TC) with a combined P-value of 4.79×10(-9). There were two potential candidate genes in the region, PCDH7 and CCKAR, with differential expression levels for rs6448771 genotypes in adipose tissue. The effect of WHR on TC was strongest for individuals carrying two copies of G allele, for whom a one standard deviation (sd) difference in WHR corresponds to 0.19 sd difference in TC concentration, while for A allele homozygous the difference was 0.12 sd. Our findings may open up possibilities for targeted intervention strategies for people characterized by specific genomic profiles. However, more refined measures of both body-fat distribution and metabolic measures are needed to understand how their joint dynamics are modified by the newly found locus.