Pelvic Osteotomies in the Child and Young Adult Hip: Indications and Surgical Technique.

Pelvic osteotomies are used for hip preservation in children and young adults to improve femoral head coverage and stabilize the hip joint. Redirectional osteotomies aim to reduce the overall volume and redirect the acetabulum. These include Salter, Pemberton, Dega, and San Diego osteotomies. Reorientation osteotomies aim to reorient the acetabulum and include periacetabular and triple osteotomies. Salvage osteotomies aim to enlarge the acetabulum and medialize the hip center. These include shelf and Chiari osteotomies. The standard anterior approach and surgical technique for the eight pelvic osteotomies used by hip preservation surgeons are described along with each osteotomy's history, indications, and outcomes.

A novel map of the mouse eye for orienting retinal topography in anatomical space.

Functionally distinct retinal ganglion cells have density and size gradients across the mouse retina, and some degenerative eye diseases follow topographic-specific gradients of cell death. Hence, the anatomical orientation of the retina with respect to the orbit and head is important for understanding the functional anatomy of the retina in both health and disease. However, different research groups use different anatomical landmarks to determine retinal orientation (dorsal, ventral, temporal, nasal poles). Variations in the accuracy and reliability in marking these landmarks during dissection may lead to discrepancies in the identification and reporting of retinal topography. The goal of this study was to compare the accuracy and reliability of the canthus, rectus muscle, and choroid fissure landmarks in reporting retinal orientation. The retinal relieving cut angle made from each landmark during dissection was calculated based on its relationship to the opsin transition zone (OTZ), determined via a custom MATLAB script that aligns retinas from immunostained s-opsin. The choroid fissure and rectus muscle landmarks were the most accurate and reliable, while burn marks using the canthus as a reference were the least. These values were used to build an anatomical map that plots various ocular landmarks in relationship to one another, to the horizontal semicircular canals, to lambda-bregma, and to the earth's horizon. Surprisingly, during normal locomotion, the mouse's opsin gradient and the horizontal semicircular canals make equivalent 6° angles aligning the OTZ near the earth's horizon, a feature which may enhance the mouse's ability to visually navigate through its environment.