Total knee arthroplasty after opening– versus closing-wedge high tibial osteotomy. A 135-case series with minimum 5-year follow-up

INTRODUCTION: High tibial osteotomy (HTO) is effective in treating isolated medial osteoarthritis of the knee, but subsequent deterioration is inevitable, and total knee arthroplasty (TKA) is then an option. The present study sought to compare TKA following medial opening-wedge HTO (OW-HTO) versus lateral closing-wedge HTO (CW-HTO) in terms of intraoperative data and clinical results. The study hypothesis was that there is no significant difference in clinical results or complications in TKA following OW-HTO or CW-HTO. MATERIAL AND METHOD: A retrospective multicenter (9 centers) study was conducted for the French Society of Orthopedic Surgery and Traumatology (SoFCOT), including 135 TKAs following HTO (58 OW and 77 CW) at a minimum 5 years' follow-up. Mean interval between HTO and TKA was 134 months and was longer in case of CW-HTO (P<0.0001). Mean age at TKA was 65.4 years and older in case of CW-HTO (P=0.021). Tibial slope was greater in case of OW-HTO (P=0.024). Prior to TKA, 55.7% of patients could walk without canes, 98.4% found stairs difficult or impossible and only 19.1% could manage a walking distance greater than 1000m. Mean flexion was 110°; 54.2% of patients showed frontal knee stability and 87.8% sagittal stability; 60.1% had a mechanical axis in varus, without difference according to OW- or CW-HTO. RESULTS: Hardware was almost systematically removed (in 98.5% of cases): in the same step for OW-HTO (P=0.018) or often in 2 steps for CW-HTO. The primary approach was generally re-used (54.2%), but less frequently in the CW-HTO group (P=0.0004). Lateral or medial ligament release was not associated in respectively 78.2% and 79.7% of cases. The TKA implant was usually without stem (87.2%) and was fitted using a conventional technique (74.4%). At a mean 87 months' follow-up, 78.5% of patients could walk without canes, stairs were still difficult or impossible for 67%, and 74.1% could now walk further than 1000m; mean flexion was 110.5°. Overall, 91.5% of patients showed frontal knee stability and 98.2% sagittal stability, without difference according to OW- or CW-HTO. There were 15 complications within 3 months, more often in the OW-HTO group (12.3%) although not significantly, and with no difference in severity. Late complications comprised loosening (5.5%) and infection (3.6%) and were more frequent in the CW-HTO group (12%) (P<0.05). DISCUSSION: The study hypothesis was partially confirmed. The only technical differences concerned hardware removal, often performed in two steps in case of CW-HTO, and TKA approach, which differed from the primary approach in case of CW-HTO. Clinical results were comparable between OW- and CW-HTO, but late complications were more frequent in the CW-HTO group

Résultats à long terme de l'ostéotomie de Chiari dans le traitement de la dysplasie acétabulaire de l'adulte.

STRASBOURG-Medecine (674822101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Effets de la présence d'un grillage métallique au sein du ciment de scellement des cupules des prothèses totales de hanche (Etude mécanique et thermique)

Nous avons étudié les effets thermiques et mécaniques de la présence d'un tissu métallique au sein du ciment de scellement des cupules des prothèses totales de hanche. Cette recherche a pour but de prolonger la durée de vie d'une arthroplastie en améliorant la stabilité des implants acétabulaires cimentés. Par analogie au béton armé, notre étude s'est articulée autour de deux phases : la phase provisoire dont la durée est celle de la reconstruction de l'articulation coxofémorale. Des essais thermiques in vitro réalisés dans des conditions proches de celles fixées par la norme ISO/DIS 5833 ont montré que le volume et la position de l'armature ont un effet statistiquement significatif sur la réduction de la température maximale de polymérisation et sur la limitation du retrait apparent du ciment lors de sa prise. Après avoir caractérisé la topographie de la surface des digitations du ciment dans l'os acétabulaire de deux hémibassins au moyen d'un rugosimètre 3D à microscopie optique confocale, nous avons reproduit la surface osseuse sur le fond d'un moule et celle de la cupule sur l'autre face. Le retrait apparent du ciment coulé dans ce moule est gêné par les digitations et le relief de l'implant. L'ancrage du ciment dans le fond du moule augmente avec la présence d'un grillage placé à proximité de cette interface et avec la section d'armatures ;la phase de service qui est celle de l'utilisation par le patient de la prothèse au cours de sa vie quotidienne. Plusieurs cas de charge (marche, course, montée et descente des escaliers, s'asseoir et se lever d'une chaise) ont été étudiés. La modélisation 3D aux éléments finis réalisée à partir du modèle géométrique de Pedersen et al. a montré que la présence d'un grillage à proximité de l'interface ciment - os est pertinente puisque les contraintes maximales de traction dans le ciment y sont observées. Ces contraintes diminuent avec l'augmentation de la section d'armatures.We studied thermal and mechanical effects of the presence of a metallic mesh in bone cement fixation of acetabular components in total hip arthroplasty. The aim of this research is to increase total hip prosthesis lifetime by improvement of cemented acetabular implants stability. By analogy with reinforced concrete this study was structured around two stages :a temporary stage which lasts until the end of total joint replacement. In vitro tests conducted in international standard ISO 5833 approaching conditions showed that steel volume and position of a mesh have a statistically significant effect on maximal temperature decrease and apparent shrinkage limitation during cement polymerisation. Surface topography of cement digitations inside acetabular bone of two hemipelves were characterized by confocal optical microscopy. Bone surface was reproduced in a mould bottom and cup surface inside of the mould plunger. Tests showed that digitations and cup relief hampered polymerising cement apparent shrinkage and that bonding between cement and mould bottom increased with the section area of a mesh placed near this interface;a service stage which is the postoperative time when the patient uses his prosthesis during daily activities. Several loading cases (walking, jogging, going upstairs, going downstairs, sitting on a chair, rising from a chair) were studied. A three-dimensional finite element analysis of the acetabular region constructed on the basis of the Pedersen et al.'s geometrical model showed that the presence of a metallic mesh near the bone - cement interface is quite pertinent because maximal tensile stresses are observed in this region. These tensile stresses decrease with mesh section area increase.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

Global radiological score for femoral cementless revision stem

International audiencePURPOSE:The purpose of this study was to evaluate the outcomes of total hip arthroplasty (THA) revision with cementless stems using a numeric global radiological score (GRxS) that summarizes two previously validated scores: secondary bone stock (SBS) and osseointegration-secondary stability (O-SS).METHOD:One hundred fifty cases of THA were evaluated at a mean follow-up of 6.5 ± 3.7 years. The GRxS combines the SBS, which evaluated cortical bone thickness, bone density and bone defects in each Gruen zone and the O-SS, which evaluated the location and extent of a single radiolucent line. To calculate the GRxS, the SBS and O-SS were each expressed on a 10-point scale and given equal weighing. The final result was a number out of 20. The GRxS was used to assign a radiological grade to each THA case: very good (20), good (18-15), average (13-12), or poor (≤ 10). The numerical mean (Nm) was calculated for each grade. The inter- and intra-observer reproducibility was evaluated.RESULTS:The inter-observer reproducibility was good (0.8) and the intra-observer reproducibility was very good (0.9). The GRxS was considered very good in 46 cases (Nm 20), good in 57 cases (Nm 16.6), average in 25 cases and poor in 22 cases. There was a significant relationship between the GRxS and the Harris Hip and Postel Merle d'Aubigné scores (p < 0.0001), and the initial bone stock (p = 0.0001).CONCLUSIONS:The GRxS is reliable and reproducible. This information can be used by surgeons to adapt the surgical technique to bone characteristics (especially during revision cases) and to compare the outcomes of different implant designs

Bone stock in revision femoral arthroplasty: a new evaluation

International audiencePURPOSE:The purpose of this study was to finalize a method allowing a qualitative and numerical evaluation of the bone stock and to confirm its reproducibility, to verify the relationship between the secondary bone stock value and the functional results, and to determine the main factors influencing the value of the bone stock.METHODS:A clinical and radiological evaluation was performed in a group of 150 revisions of total hip replacements according to a new method taking into account cortical bone thickness, bone density and bone defects.RESULTS:Interobserver reproducibility was evaluated at an average of 0.6 and intra-observer reproducibility was considered good at 0.8. Between the initial bone stock and at the last follow-up, no significant difference was noticed. For secondary bone stock considered as "very good or good", the gain was +38.1 points versus +29.9 points for patients evaluated as "average or poor" (p < 0.0001). Between the initial bone stock assessment and at last follow-up, a significant relation was found in numerical values for the global type of primary fixation and in the presence of osteopenia (p < 0.0001).CONCLUSIONS:Deficient secondary bone stock can result in less favourable functional results. The numerical scores confirm the importance of strategic choices during surgery in order to manage bone stock preservation

Intérêt mécanique du caractère pédiculé du DIDT pour une ligamentoplastie du LCA

SFA 2017 - Congrès annuel de la Société Francophone d'Arthroscopie, Marseille, France, 06-/12/2017 - 09/12/2017Le moyen de fixation d'un transplant de ligamentoplastie du ligament croisé antérieur (LCA) reste débattu. La fixation tibiale des greffes tendineuses constitue la faiblesse principale pour des raisons mécaniques et anatomiques. La ligamentoplastie aux ischio-jambiers (DIDT) pédiculés pourrait avoir un intérêt mécanique. L'objectif du travail était d'étudier l'intérêt mécanique du caractère pédiculé du DIDT en comparant la résistance maximale de la fixation tibiale d'une greffe de DIDT pédiculé par vis d'interférence à celle d'un DIDT non pédiculé fixé par vis d'interférence et à celle d'une plastie pédiculée non fixée par vis. L'hypothèse était que le caractère pédiculé de la greffe augmenterait la résistance maximale de la fixation tibiale