Surgical simulation of curved periacetabular osteotomy in four types of developmental dysplasia of the hip using finite element analysis and identification of the optimal rotation angle of the osteotomized bone.

Background: Patients with developmental dysplasia of the hip (DDH) undergo curved periacetabular osteotomy (CPO) to prevent progressive osteoarthritis. The acetabulum's morphology varies with in each DDH type. Therefore, developing a three-dimensional preoperative plan is important in CPO.

Total hip arthroplasty after failed transtrochanteric rotational osteotomy for osteonecrosis of the femoral head: analysis of three-dimensional morphological features.

Background: In total hip arthroplasty (THA) after failed transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH), deformity of the proximal femur has been reported to affect stem placement. The aims of this study were to evaluate the morphological changes in the proximal femur, muscle atrophy, and soft tissue thickening in THA after TRO and the clinical outcomes.

Methods: The TRO group included 17 patients (18 hips) who underwent THA after failed TRO.

Secure paediatric pelvic fracture external fixation using an intraoperative support device.

Secure fixation by inserting a half-pin into the iliac crest as a pelvic external fixator is important. However, the thickness of the iliac bone depends on its location and this makes it difficult to insert a half-pin accurately. The iliac crest is especially narrow in the paediatric pelvis, making it difficult to insert the half-pin accurately compared with an adult pelvis.

Embolization followed by resection of the heterotopic hip joint ossification with spinal cord injury.

Background: Heterotopic ossification of large joints, such as knees and hips, has been reported after spinal cord injury, possibly leading to decreased activity of daily living due to a limited range of motion of the affected joint. Therefore, heterotopic ossification resection is performed to improve the range of motion, but it might cause massive bleeding as a complication.

Methods: In this case, the patient had a history of spinal cord injury and developed heterotopic ossification after the left hip injury.

Visualization of acetabular coverage with radar chart before and after curved periacetabular osteotomy in dysplastic hips.

Background: Curved periacetabular osteotomy (CPO) is indicated for patients with developmental dysplasia of hip (DDH) to prevent progressive osteoarthritis. Patients with DDH have not only lateral acetabulum dysplasia but also anterior and posterior dysplasia. The full circumference acetabular coverage angle (ACA) of the femoral head should be evaluated preoperatively.

Accuracy of Acetabular Cup Placement During Total Hip Arthroplasty in Supine Position Using a Pelvic Rotation Correction Device.

Background: Accurate cup placement during total hip arthroplasty (THA) is difficult because the intraoperative pelvic position changes even in supine patient position. We developed a device known as HipPointer; it corrects pelvic rotation and creates a functional pelvic plane as a reference. The aim of this study was to determine the device placement accuracy and investigate causes of error.