MCQs – Hand 4

MCQs-Hand 4
radius out longer; pronation shortens it relative to the ulna. X-rays should therefore be taken in neutral forearm rotation with the shoulder and elbow flexed to 90.

– like SLAC wrist, the radiolunate fossa is preserved in SNAC wrist.

– the literature would support that left untreated, the natural history of scaphoid nonunions is bad – this may or may not be true, but it is what the literature tells us. Therefore, an undisplaced scaphoid nonunion should probably be fixed – either bone grafted or subjected to electromagnetic fields.

– proximal pole scaphoid fractures heal poorly; distal pole (tuberosity) fractures heal well.

– there are three pathologic cords that develop in Dupuytren’s – central cord, spiral cord, and lateral cord – the spiral cord pulls the neurovascular bundle centrally.

– if you are unable to close palmar skin after a partial fasciectomy for Dupuytren’s – you can leave it open. In the finger, you have to get the skin closed.

– in Dupuytren’s it is much harder to treat the PIP contracture than anything else (hence, you should probably try to do these when the PIP starts to get contracted.)

– a malunited scaphoid fracture will usually result in inhibited DORSIflexion

– isolate lunatotriquetral injuries usually do not cause VISI deformities – studies have shown that a tear of the palmar lunatotriquetral ligament, dorsal radiotriquetral ligament, or palmar ulncarpal ligaments is necessary also. I don’t think anyone is really sure what is required before these tear, but it seems to be accepted that you need more than lunatotriquetral injury.

– for key pinch, the primary static stabilizer is the MCP collateral ligaments; the primary dynamic stabilizer is the adductor pollicis.

– the static stabilizers of the thumb MCP are the collateral ligaments, accessory collateral ligaments, the palmar plate, and dorsal capsule – their relative importance depends on the position of the MCP joint. In flexion, the collateral ligaments are the primary joint stabilizers. In extension, the accessory collateral ligaments and palmar plate are taut and are the primary joint stabilizers against valgus stress. (That’s interesting, because when a valgus force is applied, the thumb normally is extension and yet we concern ourselves with the main UCL injury). Perhaps the palmar plate and accessory collaterals are also torn, and we just don’t bother dealing with them.

– the dynamic stabilizers of the thumb include the extrinsics and intrinsics. The adductor mechanism is of particular importance as a dynamic stabilizer. The extensor hood is formed by EPL, EPB, the sagittal bands, and the adductor aponeurosis.

– base of 1st metacarpal fractures that are extra-articular tolerate quite abit of angulation and one should resist overtreating them.

– the most common bug in flexor tenosynovitis is staph aureus.

– occult intra-osseous ganglia can cause pain in the carpal bones – watch out for them in the scaphoid.

– the Dupuytren’s contracture does not typically involve Cleland’s ligament (dorsal to the NV structures in the finger). The pathologic cord involves the palmar fascia, natatory ligament, spiral band, and Greyson’s ligament (volar to the NV structures in the finger). A good way to remember this is that the spiral band moves from volar to dorsal to the NV structures, then emerges in the finger VOLARLY, thereby wrapping up the NV bundle and pulling it centrally. If it went dorsally to involve Cleland’s, it would not have this effect on the NV bundle.

– the annular pulleys 1 and 3 arise from the volar plate and do not arise from the phalanges. Remember the order: A1, A2, C1, A3, C2, A4, C3, A5

– the most important stabilizer of the DRUJ is the TFCC

– the TFCC consists of articular disc, meniscal homologue, dorsal radioulnar ligament, volar radioulnar ligament, ulnolunate ligament, ulnotriquetral ligament, sheath of ECU (2 cartilaginous structures, 5 ligamentous structures)

– attritional rupture of EPL after distal radius fracture is best treated with