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21 Cards in this Set
- Front
- Back
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What is the stable joint of the forearm? What results from excision of the ulnar head?
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Ulna is the stable joint of the forearm; radius is suspended by IOM, annular ligament and TFCC. Stability maintained by tone of muscles and articular congruity of PRUJ and DRUJ. Ulnar head excision destabilizes entire forearm joint.
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What is a Monteggia fracture? Treatment?
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Fracture of proximal ulna with dislocation of PRUJ. Requires anatomical fixation with rigid fixation.
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What is a Galeazzi fracture? Treatment?
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Fracture of distal third of radial shaft with subluxation or dislocation of DRUJ. Treatment is surgical.
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What is an Essex-Lopresti lesion? What structures are affected? Treatment?
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Longitudinal transfer of force through wrist, forearm, up to the elbow. Affects radial head, IOM, DRUJ including TFCC. Treatment involves maintaining the radial head, with stabilization if necessary.
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What is treatment for an established/chronic Essex-Lopresti lesion?
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Radial head replacement (if still feasible - alignment of neck with capitellum is not possible after a certain time). Distal ulnar shortening osteotomy will reduce ulnacarpal impaction sx. No established technique for IOM reduction.
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What is the clinical sign of DRUJ dislocation?
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Piano keying - painful in acute state
Prono-supination is painful and limited |
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What are three types of distal ulna fractures?
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Ulnar styloid, head, and neck fractures.
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What is the treatment of an ulnar styloid fracture - of tip? of base?
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Tip: Common with distal radial fractures. Stable, treat symptomatically.
Base: associated with DRUJ instability, because fragment includes fovea where TFCC attaches. If displaced, secure with screw or tension band. |
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What is the treatment of an ulnar head fracture? Is a Darrach's helpful?
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Fixation is difficult. If good bone, fix with buried screws. If poor/comminuted, consider ulnar head replacement. Darrach's yields poor results.
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What injury is an ulnar neck fracture associated with? Treatmnet?
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Associated commonly with distal radius fractures. Should be surgically treated at time of distal radius fixation to prevent deformity and prono-supination limitation.
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What comprises the TFCC?
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Anterior and posterior radioulnar ligaments
Meniscal homologue Ulnocarpal ligaments Underside of ECU sheath |
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What is the most commonly fractured carpal bone?
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Scaphoid.
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What anatomical feature of the scaphoid makes it a challenge for management?
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Main blood supply enters distally and dorsally (br of radial artery)
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In what three locations may the scaphoid fracture? Which is the most common? Which tends to heal best? Worst?
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Tubercle, waist, or proximal pole.
Waist most common. Tubercle heals well (good blood supply, low mechanical demands), proximal pole heals worst (poor supply, high rate of nonunion) |
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What is the typical mechanism for a scaphoid fracture?
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FOOSH
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What is the basic management plan for a suspected scaphoid fracture not visible on plain films?
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Splint and repeat XR in 2 weeks. If asymptomatic, may d/c plaster; if still painful, and XR still negative, try another 2 weeks, or CT, MRI, bone scan.
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How is a undisplaced scaphoid waist fracture treated?
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Scaphoid plaster 8 weeks, then XR f/u. Offer percutaneous fixation to those who cannot tolerate plaster for that long.
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WHat percentage of waist and proximal pole scaphoid fractures go on to nonunion? How long should one wait before diagnosing nonunion? What imaging is helpful?
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10-15% waist fractures, 30-40% proximal pole fractures. 12 weeks should be allowed for union. CT helpful, MRI not.
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What factors predispose to scaphoid fracture nonunion?
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Proximal pole involvement, delay in dx >3 weeks, unstable/displaced waist fracture, smoking, inadequate immobilization or fixation
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What are treatment options for a scaphoid nonunion?
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1. Benign neglect: in pts >50, low demand, who are aware of possible sequelae of OA and SNAC wrist.
2. Percutaneous fixation and bone grafting: when alignment preserved. 3. Wedge bone grafting and internal fixation (Fisk-Fernandez) - for young pts with manual occupations, humpback deformity. >80% union. 4. Inlay graft and internal fixation (cancellous graft packed in) 5. Vascularized bone grafting: variety of donors described |
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What percentage of scaphoid fractures are not seen on initial XR?
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25%
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