MCQs – Hand 3

MCQs-Hand 3
create a Chinese finger trap that, when traction is applied, prevents the relocation of the head. The primary block to reduction, however, is the volar plate.

Jersey fingers (FDP avulsions) should be approached as early as possible, especially if the tendon retracts all the way into the palm.

Mallet fingers can be treated with splinting up to 12 weeks after initial injury.

The trapeziometacarpal joint is the most commonly affected joint in the wrist (with degenerative OA).
After that, may be most common in the radioscaphoid joint – a debatable thing. Not sure if this is more common than scaphotrapezial. Scaphotrapezial OA is often associated with trapeziometacarpal OA, which is exceedingly common.

The best management of a Barton’s fracture (volar, intra-articular fracture of the distal radius) is ORIF volarly with buttress plate.

Patients with carpal tunnel syndrome should have their treatment based on clinical findings. Do not rely on NCS and EMG which can both be normal and do not rule out the diagnosis.

The sagittal bands help tether and support the long extensors over the MCP

Early Keinbock’s disease can be treated with radial shortening, ulnar lengthening, or STT fusion. By “early”, I think they mean pre-collapse (I, II, or IIIA) – all of these can be treated by dealing with the ulnar variance, and perhaps with limited wrist fusion (STT) or PRC.

Etiology of Keinbock’s – probably microtrauma. 20% of the population has an aberrant blood supply (not 30%). Ulnar minus variance is a predisposing factor.

When radially deviating, the scaphoid and lunate flex; when ulnarly deviating, they both extend.

The carpal height ratio is .54 +/- .03

The most common nerve injury after perilunate dislocation is median nerve compression.

In SLAC wrist, depending on the stage and involvement of the joints, you can do a radial styloidectomy, scaphoid excision and 4 corner fusion, proximal row carpectomy, or (if radiocarpal and midcarpal involvement) total wrist fusion. Remember, the radiolunate fossa is almost always preserved until very late in the course of disease. (This is why you can get away with a radial excision and 4 corner fusion – because the radiolunate fossa is okay).

– remember: SLAC starts at radial styloid with distal scaphoid vs radial styloid degeneration. Then progresses to diffuse radioscaphoid involvement, then to scaphocapitate involvement, then capitolunate involvement (which signifies midcarpal collapse).

– limited fusions possible for SLAC wrist include STT, SC, and four corner with scaphoid excision.

– lunatotriquetral dissociation leads to VISI deformity.

– the dorsal radiocarpal ligaments are also important in the development of the VISI deformity – some feel that a lunatotriquetal ligament tear alone is insufficient to create the VISI deformity, and that the dorsal radiocarpal ligaments must also be torn. Some say that tearing the dorsal radiocarpal ligaments alone can cause a VISI deformity too!

– a 9 month old scaphoid malunion with DISI deformity – treat with Fernandes procedure: volar approach, intercalary bone graft, Herbert screw. (Russe is a non-instrumented inlay bone graft)

– a patient 3 weeks out with a scapholunate injury should probably undergo open reduction and internal fixation. Should probably try fixing these as long as they have not progressed past stage I SLAC (in stage I SLAC you do the radial styloidectomy and fix the scapholunate ligament)

– signs of scapholunate dissociation: widened S-L space (>3 mm), shortened scaphoid with ring sign, triangular lunate, DISI deformity on lateral x-ray.

– perilunate dislocations are caused by hyperextension.

– avascular necrosis of the lunate is unusual in perilunate dislocations because the volar ligamentous blood supply is maintained to the lunate (volar radiolunate ligament)

– in an ulnar negative wrist, supination makes the ulnar negative variance appear worse. Conversely, pronation will tend to underestimate it; remember – supination brings the