Musculoskeletal Trauma of the Wrist

Transcription

1 September 2000 Musculoskeletal Trauma of the Wrist Murat Akalin, Harvard Medical School, Year- IV Gillian Lieberman, MD

2 The Wrist Most common site of injury in entire skeleton Distal radius and ulna fractures are 10 times more common than carpal bone fractures Mechanism of injury is most often Fall On OutStretched Hand FOOSH 2

3 The Wrist Complex anatomy makes identification of abnormalities difficult Dislocations are easy to overlook Complications are significant so these fractures are among the MUST NOT MISS radiologic diagnoses 3

4 Anatomy 4

5 Anatomy Radiographic Anatomy of the Skeleton Michael L.Richardson, M.D. 5

6 Anatomy Modified from Radiographic Anatomy of the Skeleton Michael L.Richardson, M.D. 6

7 Anatomy capitate 7

8 Zone of Vulnerability 8

9 Standard Imaging Studies for Suspected wrist trauma or Wrist series complications PA, lateral, and oblique plain films Special views usually of scaphoid CT scan useful for occult fractures, fragments, nonunion, osteonecrosis 9

10 Other Imaging Studies (Less Useful in Evaluation of Acute Injury) MRI Early/occult osteonecrosis cartilaginous and ligamentous injuries marrow processes Arthrogram disruption of ligamentous compartments Flouroscopy Carpal instability with reproducible symptoms Bone scintigraphy Occult fractures Osteomyelitis 10

11 Common Wrist Fractures 11

12 Case 1: 23 Year Old with FOOSH Fracture 12

13 Scaphoid (navicular) Fracture Most commonly fractured carpal Difficult to detect Frequently occult, becoming evident only over time (5-10 days) If there is snuff box tenderness, special scaphoid view(s) should be requested 13

14 Scaphoid View Ulnar flexion Better visualisation of radial surface of scaphoid, where fractures often occur Fourth view often added to standard wrist series Variety of other special scaphoid views Image from Raby, Berman and Lacy. Accident and Emergency Radiology,

15 Multiple Scaphoid Views 15

16 Osteonecrosis of the Scaphoid 5-15% of scaphoid fractures Increased radiodensity over proximal pole Take weeks to appear Likelihood depends on location of fracture line Other complications: nonunion, instabilty, DJD Complications increase with delayed diagnosis and treatment Electronic Journal of Hand Surgery

17 Wrist CT 17

18 CT Reconstruction 18

19 Scaphoid Fracture s/p ORIF 19

20 n pearl Scaphoid Fracture Common Difficult to detect Especially prone to complications May become radiographically evident only over time Therefore If scaphoid views are requested, the patient MUST be followed-up radiographically, even if initial studies are negative 20

21 Case 2: 60 Year Old with FOOSH 21

22 Colles Fracture Transverse fracture of distal radius Distal fragment angulated dorsally Often comminuted Often impacted 60% have associated ulnar styloid fracture 22

23 Case 3: 6 Year Old with FOOSH Radiology Cases in Pediatric Emergency Medicine, (1)

24 Greenstick Fracture Children Greater bone elasticity Break in 1 cortex Usually angulated Usually not subtle Radiology Cases in Pediatric Emergency Medicine, (1)

25 Case 4: 6 Year Old with FOOSH Radiology Cases in Pediatric Emergency Medicine, (1)

26 Torus Fracture Children Buckling of 1 cortex Variant of greenstick Little or no angulation Often subtle and easily missed Radiology Cases in Pediatric Emergency Medicine, (1)

27 Case 5: 16 Year Old with FOOSH Radiology Cases in Pediatric Emergency Medicine, (1)

28 Salter-Harris Fracture Involves growth plate Risk of premature fusion and deformity S-H classification predicts risk May be impossible to detect radiographically Therefore tenderness at growth plate should be treated as S-H fracture, even in absence of radiographic evidence Radiology Cases in Pediatric Emergency Medicine, (1)

29 Salter-Harris Classification American Family Physician Vol. (46), number 4 29

30 Kids: Common Wrist Fractures Greenstick Fracture Torus Fracture Salter-Harris Fracture Adults: Scaphoid Fracture Colles Fracture 30

31 Wrist Dislocations 31

32 Dislocations of Wrist Less common than fractures, but still comprise about 10% of carpal injuries Anatomy may be confusing at first, but a few simple tips will make it easy 32

33 On the Frontal View Look for Three Arcs Clear, smooth, and continuous Spaces should be 2mm or less Disruption in any one of these arcs signifies dislocation Arc 1 Arc 3 Arc 2 33

34 On the Lateral View Look to see that the radius + lunate and lunate + capitate articulate Like an apple in a cup in a saucer If the cup is empty, there is a dislocation Image from Raby, Berman and Lacy. Accident and Emergency Radiology,

35 Lunate Dislocation Most common dislocation Best seen on lateral view On frontal view, Arcs 2 and 3 disrupted and pie sign is present Treatment is traction and closed reduction vs ORIF and ligamentous repair Image from Raby, Berman and Lacy. Accident and Emergency Radiology,

36 Perilunate Dislocation Best seen on lateral view On frontal view, again, Arcs 2 and 3 are disrupted Often associated with scaphoid fracture Image from Raby, Berman and Lacy. Accident and Emergency Radiology,

37 Navicular Subluxation (Scaphoid Dislocation AKA Scapholunate Dissociation) Image from Raby, Berman and Lacy. Accident and Emergency Radiology, Second most frequent carpal dislocation Subluxation, not a full dislocation David Letterman sign (aka Terry Thomas sign) Ring sign Arcs 1 2 & 3 disrupted Often associated with radius fracture 37

38 Common Wrist Dislocations Lunate dislocation : pie sign Perilunate dislocation Navicular subluxationi: David Letterman/Terry Thomas Sign Ring Sign 38

39 Summary Common fractures may be predicted from the age of patient: Child Greenstick Teen Salter-Harris Adult Scaphoid Older Colles Particular vigilance required for scaphoid fractures CT is modality of choice for detecting occult fractures Dislocations may be detected with knowledge of normal carpal relations 39

40 References Chew F. Skeletal Radiology: The Bare Bones. 1 st edition, Dee R, Mango E, Hurst L. Principles of Orthopaedic Practice Eisenberg R. Clinical Imaging: An Atlas of Differential Diagnosis. 3 rd edition Hodge J, Gilula L. Imaging of the Wrist and Hand Rogers L. Radiology of Skeletal Trauma. 2 nd edition, Raby N, Berman L, de Lacey G. Accident and Emergency Radiology Brown J., Deluca S. Growth Plate Injuries: Salter Harris Classification American Family Physician Volume(46), number 4, Figure 2. 40

41 Acknowledgements Beverlee Turner Larry Barbaras The end. 41