MCQs-Hip recon 1
– a valgus intertrochanteric osteotomy would decrease the lever arm of gluteus medius. Similarly, a varus intertrochanteric osteotomy would increase the lever arm
– most Pipken II fractures that are not reduced anatomically should be fixed, or an endoprosthesis performed if in elderly
– stress fractures of the femoral neck – more worrisome on the lateral tension side than on the medial compression side. If the fracture has any involvement of the lateral cortex, then fix. If the fracture involves just the medial cortex, you can start with feather weightbearing.
– 4 most common associations for avascular necrosis include alcoholism, corticosteroids, and trauma; the fourth is idiopathic. The other precipitating conditions include hemoglobinopathies, Gaucher’s disease, Caisson’s disease, hematologic neoplasia, SLE, organ transplantation, pancreatitis, irradiation, hyperuricemia, and pregnancy.
– in a 28 year old pregnant woman who develops hip pain – the clue is that she is pregnant and may have AVN – get an MRI to make the diagnosis, then probably treat with feather weightbearing until child is born.
– Obturator nerve – anterior and posterior branches. Anterior branch passes through adductor brevis and then between adductor brevis and longus, and supplies longus, brevis, and gracilis. Posterior branch pierces obturator externus and supplies it, then runs down behind adductor brevis between brevis and magnus. It supplies the adductor portion of magnus (the rest of magnus – the ischiocondylar part – is supplied by tibial branches of the sciatic).
– if you were to do an obturator neurectomy, the ischiocondylar part of the adductor magnus would remain because it is innervated by the sciatic nerve, and although it is more of a thigh extendor and medial rotator, it would probably also adduct the limb. Pectineus is innervated by the femoral nerve and lies proximally but in the same plane as adductor longus – it adducts the thigh as well.
– in the ilioinguinal approach, the interval between the iliopsoas & lateral cutaneous femoral nerve (the lacuna musculorum) and the external iliac artery/vein & lymphatics (the lacuna vasorum) will expose the quadrilateral plate. Lateral to the lacuna musculorum gives you exposure to the iliac crest, fossa, anterior column, and SI joint at the back. Between the lacuna musculorum and vasorum exposes the pelvic brim all the way along the anterior column back to the SI joint, the quadrilateral plate, and the posterior column. Medial to lacuna vasorum is the spermatic cord, and once this is mobilized, the entire superior pubic ramus and symphysis pubis is exposed (watch for corona mortis).
– important to remember that after mobilizing the lacuna musculorum, you need to incise the iliopectineal fascia to access the quadrilateral plate. The iliopectineal fascia separates the lacuna musculorum from the vasorum and unless you cut it, you will never be able to mobilize the structures beneath the inguinal ligament.
– the nerve exiting above piriformis is the superior gluteal – cutting it will result in weakness of gluteus medius, gluteus minimus, and tensor fascia lata.
– ABOVE piriformis: superior gluteal artery and nerve 2 above
– BELOW piriformis: sciatic nerve 8 below
posterior femoral cutaneous nerve
inferior gluteal artery and nerve
nerve to obturator internus
internal pudendal artery
nerve to quadratus femoris
– in the anterior Smith Peterson approach, the most common injury is to the lateral femoral cutaneous nerve.
– a number of questions ask about the LEAST important vessels in the blood supply of the femoral head between the ages of 0-2. The choices include the medial epiphyseal, lateral epiphyseal, superior metaphyseal, inferior metaphyseal, and medial circumflex. At birth, the metaphyseal vessels are pretty important, because the head is cartilaginous and the physis has not yet really developed. Once the physis develops it is a barrier to these vessels and the