The purpose of this study was to analyze the effect of femorotibial alignment (FTA), femoral and tibial component alignment, correction of malalignment, and thickness of tibial osteotomy on implant loosening following total knee replacement. We retrospectively reviewed 107 knees in 65 patients with a minimum of six months of follow-up. The 107 knees were operated by two surgeons using BS4+ (Bisurface 4 plus) implant (Japan Medical Materials, Japan); the femoral component was cemented, and the tibial component was either cemented or not cemented by using four screws. All the replacements were performed under same operative procedure with medial para-patellar approach and measured bone technique. The knees were classified into two groups (: I and U) on the basis of postoperative radiological findings that indicate the loosening of tibial components. First, there were not any apparent loosening symptom like radio-lucent lines nor sinking; group-I (intact, n=75). Second, there were some radio-lucent lines around tibial component; subgroup-R (radio-lucent lines, n=25), or some subsidence of component over 2 mm; subgroup-S (subsidence, n=7), and the latter two subgroups were put into group-U (unstable, n=32) all together. We measured preoperative and postoperative alignment (overall FTA, correction of malalignment, and alignment of the tibial and the femoral component in the coronal plane). Furthermore, each thickness of tibial osteotomy was measured with use of preoperative and postoperative radiographs of the knee. These parameters including patient's BMI were compared between two major groups statistically to evaluate the factor influencing the stability of tibial components. Moreover, the thickness of tibial osteotomy were compared between two subgroups.Background
Methods
Subtrochanteric femoral shortening and corrective osteotomy are considered to be an integral part of total hip arthroplasty for a completely dislocated hip or severe deformity of the proximal femur. A number of alternative femoral osteotomy techniques, transverse, oblique, step-cut, and V-shaped, have been described. Becker and Gustilo reported the “double-chevron subtrochanteric shortening derotational femoral osteotomy,” which is reasonable in that the osteotomy site is torsionally more stable and can be stabilized with a shorter stem. We have simplified this procedure, and performed it without a trochanteric osteotomy. We describe a simplified double-chevron osteotomy and provide the clinical results from a series of 22 successful procedures. In this series, we performed 22 cementless total hip arthroplasties combined with double-chevron subtrochanteric osteotomies between 1997 and 2002. There were 17 females and 2 males. Their average age at the time of the operation was 59 years old (range, 41–74 years old). Thirteen of these hips were congenitally dislocated hips (Crowe IV), and 8 hips were after proximal femoral osteotomies using a procedure described by Schanz or valgus osteotomy, and 1 hip was an ankylosed hip in malposition.Background
Methods
Dislocation is one of the commonest complications of total hip arthroplasty (THA) with incidence of between 0.3 and 10% in primary, and from 15 % to 30% of revision cases. Despite this, little is known of the outcome of treatment strategies for dislocation. In this study, we evaluated clinical results in patient undergoing revision THA for recurrent dislocation. Twenty-four hips underwent revision THA for recurrent instability between 1998 and 2011 at our institution. Nine patients were male, and 15 were female. At the time of revision, the average age was 69.9 years (range, 45–83 years). Average follow-up was 29.8 months (range, 6–72 months). We recorded the number of times of dislocation, the direction of dislocation, the factor of dislocation and the operative strategy employed for each case. Demographic data and surgical treatment used were analyzed to determine risk factors for failure. We performed Mann-Whitney rank sum test, Student's t-test and Fisher exact test to evaluate the factors influencing failure. Significance was defined as a p value of <0.05 (Statistical Package for Social Sciences (SPSS) version 12.0 J for Windows (SPSS Inc., Chicago, IL, USA)).Background
Materials and Methods
