MCQs – Lower Extremity 1

MCQs-LE 1
MCQs-LE
– a multi-traumatized child with head injury and femur fracture should be treated with ORIF, even if in traction that is keeping things well aligned. PERIOD. External fixation would be acceptable too.

– antegrade standard intramedullary nailing of a femur in a skeletally immature patient has an unacceptable risk of AVN.

– a 2.5 year old child with Bount’s is a candidate for single upright bracing. The braces we use are a Denis/Brown boots and bar system with a single midline upright that has straps for the knees. The straps pull the knees in towards midline while the boots and bar keep the feet apart, thus applying a valgus force to the knees. The boots and bar is also helpful to reduce the internal tibial torsion that develops with this deformity – you can point the toes outwards! The best results are to perform the surgery before the age of 4 – so get on and treat this kid with bracing NOW. If he is not corrected by age 4, you should probably do the surgery.

– one of the multiple choice questions asks about when the best time is for a child to undergo operative treatment for Blounts – depending on who you read, it is 4-5 years.

– the most significant factor in the prognosis of osteochondritis dessicans is skeletal maturity. Also important I guess is the size of the lesion, but really, skeletal maturity has the greatest influence on healing, and this is what it is all about.

– for calculating leg length discrepancy, keep in mind the arithmetic method;
– girls stop growing at age 14; boys stop growing at age 16.
– the distal femoral physis grows about 1 cm per year, the proximal tibial physis grows about .6 cm per year.

– for deciding what to do about leg length discrepancy, keep in mind what the guidelines are for ultimate discrepancy at skeletal maturity:
– for 0-2 cm – shoe lift
– for 2-5 cm – epiphyseodesis
– for 5-15 cm – leg lengthening
– for greater than 15 cm – probably better to amputate

– you can always gain a little by shutting down the growth plate of the other side – beware the kid that is already pretty short!

– triplane fractures are lateral rotation injuries

– posteromedial bowing of the tibia is often detected at birth – it is different from the anterolateral bowing of congenital pseudarthrosis. It typically resolves to the most extent, and the biggest thing to worry about is LEG LENGTH discrepancy.

– for proximal metaphyseal fractures of the tibia, even when reduced anatomically, there is an usual preponderance of late valgus deformity that you need to watch for. The etiology of this is unclear

– for a 9 year old with severe femoral anteversion (with barely any passive external rotation), you may need to do femoral osteotomy at the intertrochanteric level.

– for a Sharrard transfer of iliopsoas to GT – need L1/2 function.

– for a discoid meniscus, the Wrisberg type has the poorest prognosis

– a ball and socket ankle joint is associated with short femur, fibular hemimelia, hypoplastic lateral femoral condyle, absent rays on the lateral aspect of the foot, and tarsal coalition. (In fact, some say that it is a response of the ankle to the stiffness of the hindfoot in tarsal coalition) It is not seen with cavus foot deformity

– the anterolateral aspect of the distal tibial physis closes last – ie. Tillaux fracture.

– for the intoer adolescent – there are some guidelines about when to pull the trigger on their osteotomies:
– Rotational osteotomy of the femur is indicated if medial hip rotation is more than 85 and external rotation is less than 10, or if on CT scan their anteversion is greater than 50 degrees.
– In general, rotational osteotomies should not be performed before the age of 10 because kids tend to improve up till this point.
– On the tibia, a medial thigh foot angle (or transmalleolar angle) of more than 10 degrees is probably sufficiently pathologic internal tibial torsion to do something.
– On the tibia, a lateral thigh foot angle greater than 35 degrees is sufficiently pathologic external