[Tibial valgus osteotomy]. / Ostéotomie tibiale de valgisation.

The tibial valgus osteotomy whatever its technique has a survival rate of about 85 % to 10 years, if we consider the reoperation as a criterion of failure, with a confidence index at 78%. The age, weight, sex and functional signs have no impact on the outcome. We have found no evidence in the preoperative radiographic assessment, neither the medial pinch, or varus epiphyseal neither varisant gap, which could be a failure and a reoperation before the tenth year. Good results were observed significantly when there is an over-valgus at least 3 degrees of global axis of the lower limb. This corresponds to a valgus epiphyseal by more than 2 degrees . The substantial reduction in the gap varisant that lowers the overall time varisant below 200 kg cm provides the same positive results. The outcome will depend directly on the accuracy of the calculation of the preoperative correction performed and the quality of surgical achievement. Because of the need for precision, navigation technique appears as reliable, simple which makes it also possible to monitor the front slope and tibial rotation induced. The osteosynthesis must be stable and rigid to avoid postoperative loss of correction.

Femoral offset: anatomical concept, definition, assessment, implications for preoperative templating and hip arthroplasty.

UNLABELLED: BACKGROUND OBJECTIVE: Femoral offset is supposed to influence the results of hip replacement but little is known about the accurate method of measure and the true effect of offset modifications. MATERIAL AND METHODS: This article is a collection of independent anatomic, radiological and clinical works, which purpose is to assess knowledge of the implications of femoral offset for preoperative templating and total hip arthroplasty. RESULTS: There is a strong correlation between femoral offset, abductors lever arm and hip abductor strength. Hip lateralization is independent of the femoral endomedullary characteristics. The abductors lever arm is highly correlated to the gluteus medius activation angle. There were correlations between femoral offset and endomedullary shape. The hip center was high and medial for stovepipe metaphysis while it was lower and lateralized for champagne - flute upper femur. A study was performed to compare the femoral offset measured by X-ray and CT-scan in 50 patients, demonstrated that plain radiography underestimates offset measurement. The 2D templating cannot appreciate the rotation of the lower limb. Taking into account the horizontal plane is essential to obtain proper 3D planning of the femoral offset. A randomized study was designed to compare femoral offset measurements after hip resurfacing and total hip arthroplasty. This study underlined hip resurfacing reduced the femoral offset, while hip replacement increased offset. However, the reduction of femoral offset after hip resurfacing does not affect the function. A pilot study was designed to assess the results of 120 hip arthroplasties with a modular femoral neck. This study showed that the use of a modular collar ensures an easier restoration of the femoral offset. A cohort of high offset stems (Lubinus 117 degrees) was retrospectively assessed. The survival rate was slightly lower that the standard design reported in the Swedish register. Finally, the measurement of offset and leg length was assessed with the help of computer assistance. The software changed the initial schedule (obtained by templating) in 29%. CONCLUSION: Therefore, femoral offset restoration is essential to improve function and longevity of hip arthroplasty. CT-scan is more accurate than plain radiography to assess femoral offset. Hip resurfacing decreases offset without effect on function. Modular neck and computer assistance may improve intraoperative calculation and reproduction of femoral offset. Increasing offset with a standard cemented design may decrease long-term fixation. Level IV: Retrospective or historical series.