ABFAS Basic Science Exam Questions and Answers All Correct

ABFAS Basic Science Exam Questions and Answers All Correct How many muscles are associated with the 1st MPJ? - Answer-6 all together: 2 Extrinsic (EHL, FHL) 4 intrinsic (EHB, FHB, abductor hallucis, adductor hallucis) What makes up the 1st ray? - Answer-1st metatarsal & medial cuneiform How does the axis of the 1st Ray run? - Answer-Axis runs from anterolateral/slightly plantar to posteromedial/slightly dorsal and is angled about 45 degrees from both the frontal and sagittal planes with little divergence from Transverse. As the 1st ray DF; it inverts and as it PF; it everts What is the axis of the 1st MPJ? - Answer-The 1st MPJ has 2 axis. Vertical (DF/PL) & horizontal (ABD/ADD); there is no longitudinal axis & therefore any frontal plane motion of the great toe is abnormal. What is normal ROM of 1st MPJ? - Answer-During static examination the ROM is only 45 degrees (Hallux DF 21-25 degrees + 20 degrees of metatarsal declination) without movement of the first ray. The total ROM of the 1st MPJ during closed kinetic chain motion is 65-75 degrees What is the normal angle of the following? Hallux Abductus: DASA: PASA: Metatarsus primus adductus (IMA): Hallux Interphalangeus (HI): Metatarsal Protrusion Angle: MA: Tibial Sesamoid Position: - Answer-Hallux Abductus: 15 DASA: 7.5 PASA: 7.5 Metatarsus primus adductus (IMA): 8 Hallux Interphalangeus (HI): 0-10 Metatarsal Protrusion Angle: +/- 2mm MA: 10-20 Tibial Sesamoid Position: 1-3 (tibial sesamoid) What information does the tibial sesamoid position give you? - Answer-The position of the tibial sesamoid is used as an indication to remove the fibular sesamoid. Generally, the fibular sesamoid should be removed when the tibial sesamoid is in a position of 4 or more. In this position, the sesamoid is resting on or over the crista of the first metatarsal and thus is usually eroded What shape of the metatarsal head is the most stable? - Answer-When the metatarsal head is square with a ridge it is the most stable vs. round shape which is the most unstable What are the 5 normal first ray essentials - Answer-1. Supinated position of the foot in propulsion 2. Normal metatarsal length pattern (2 longer than 3) 3. Normal strength & phasic activity of muscles 4. Normal sesamoid apparatus 5. Stable base of the proximal phalanx What is the most common etiology for HAV deformity? - Answer-Hypermobility of the 1st ray secondary to subtalar joint pronation or ligament laxity What are other etiologies of HAV deformity - Answer-1. Metatarsal deviation caused by asymmetric growth of the met base 2. Metatarsus primus varus >20 degrees (line bisecting 1st met with medial cuneiform) 3. Relative metatarsal protrusion length 4. Rotational deformities (i.e. internal rotation of hip, femur, knee, tibia or foot) 5. Inflammatory joint disease What is the definition of a Congruous 1st MPJ - Answer-The head of the first metatarsal completely articulates with the base of the proximal phalanx and that the joint space is equal. The line bisecting the 1st met and proximal phalanx are parallel What is the definition of a Deviated 1st MPJ - Answer-An abductus of the hallux within the joint. The base is not displaced off of the head; however, the medial aspect of the head is exposed. The joint space is no longer equal throughout. The lines intersect outside of the joint What is the definition of a Subluxed 1st MPJ - Answer-An abductus of the hallux within the joint. The base of the proximal phalanx does not completely articulate with the metatarsal head. The medial aspect of the head is very much exposed and the joint space is no longer equal. The lines intersect within the joint What is a structural bunion deformity? - Answer-It's when the PASA + DASA = HAA. The joint in this type of deformity is CONGRUENT. The PASA or DASA in this case are abnormal What is a positional bunion deformity? - Answer-It's when the PASA + DASA < HAA. The joint in this type of deformity is SUBLUXED or DEVIATED. The PASA or DASA in this case are normal What is a combined (structural + positional) bunion deformity? - Answer-It's when the PASA + DASA < HAA. The joint in this type of deformity is SUBLUXED or DEVIATED. The PASA or DASA in this case are abnormal What is os tibiale externum? - Answer-It is an accessory navicular that is located at the posteromedial aspect of navicular tuberosity, within insertional fibers of tibialis posterior What is an Os Vesalianum? - Answer-It is an accessory ossicle often found to be within the peroneus brevis muscle tendon at it's attachment point to the 5th metatarsal base What is an os peroneum where is it located? - Answer-It is a sesamoid bone located within the peroneus longus tendon near the cuboid