Deformity after femoral osteotomy varies between patients. Some researchers reported good results when using cemented stems for the hips after femoral osteotomy, but there are many disadvantages that obstruct ideal fixation using cemented stems. Therefore, we developed cementless custom-made stems and inserted those using a computed tomography (CT) –based navigation system Eighteen dysplastic hips of 15 patients after intertrochanteric osteotomy were investigated in the present study. Individual computed tomography data were used to manufacture cementless custom-made femoral stems out of Ti-6Al-4V. The proximal 1/3 of each stem was coated using porous coating covered with hydroxyapatite coating. The stems were inserted using a CT-based fluoro navigation system for accuracy of insertion. The average patient age at time of surgery was 66 years, and the average follow-up period was 3.5 years.Introduction
Methods
The purpose of this study was to clarify the relationship between the laxity of surrounding soft tissue and artificial joint kinetics during knee articulation, where total knee arthroplasty had been performed using ceramic LFA artificial knee joints (LFA-TKA below) from Japan Medical Materials (JMM). The subjects of the study were 47 knees in 40 LFA-TKA recipients whose cooperation could be obtained. The CR type joint (posterior cruciate retention design) was used in 33 knees in 27 recipients and the PS type joint (posterior cruciate stabilizer design) was used in 14 knees in 13 recipients. OA patients received 30 CR type and 8 PS type joints while RA patients received 3 CR type and 6 PS type joints. For analysis of post surgery knee joint kinetics, using digital fluoroscopy, lateral images were taken of knee motion from a loaded squat position to the erect standing position. Using Knee Motion® software the imaging data was evaluated for 1) femoral rollback, 2) tibial axial rotation patterns, and 3) pivot center position, from analysis of lateral and medial condylar translation (femoral components) at the point of contact with the tibial insert, starting from the extended position. Subsequent imaging under medial-lateral and posteroanterior stress was performed to measure the medial-lateral dihedral angle changes and posteroanterior movement, and the relationship of those factors to the dynamic patterns was evaluated.Purpose
Materials Methods
