Updated: 9/28/2018

Hook of Hamate Fracture

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https://upload.orthobullets.com/topic/6035/images/hamate_golf.jpg
https://upload.orthobullets.com/topic/6035/images/hamate_baseball.jpg
https://upload.orthobullets.com/topic/6035/images/carpals.jpg
https://upload.orthobullets.com/topic/6035/images/hamate_lat.jpg
https://upload.orthobullets.com/topic/6035/images/hamate_anatomy.jpg
Introduction
  • Epidemiology
    • incidence
      • 2% of carpal fractures
    • risk factors 
      • often seen in athletes
        • golf
        • baseball
        • hockey
  • Pathophysiology
    • typically caused by a direct blow
      • grounding a golf club
      • checking a baseball bat
  • Associated conditions
    • bipartite hamate
      • will have smooth cortical surfaces
Anatomy
  • Hamate
    • one of carpal bones, distal and radial to the pisiform
    • articulates with
      • fourth and fifth metacarpals
      • capitate
      • triquetrum
    • hook of hamate
      • forms part of Guyon's canal, which is formed by
        • roof - superficial palmar carpal ligament
        • floor - deep flexor retinaculum, hypothenar muscles
        • ulnar border - pisiform and pisohamate ligament
        • radial border - hook of hamate
      • one of the palpable attachments of the flexor retinaculum
      • deep branch of ulnar nerve lies under the hook
Presentation
  • Symptoms
    • hypothenar pain
    • pain with activities requiring tight grip
  • Physical examination
    • provocative maneuvers
      • tender to palpation over the hook of hamate  
      • hook of hamate pull test:
        • hand held in ulnar deviation as patient flexes DIP joints of the ulnar 2 digits, the flexor tendons act as a deforming force on the fracture site, positive test elicits pain
    • motion and strength
      • decreased grip strength
    • neurovascular exam
      • chronic cases
        • parasthesia in ring and small finger
        • motor weakness in intrinsics
Classification

 Milch Classification
Description Subtypes Image
Type I  Hook of hamate fx (most common) 
 • I - avulsion
 • II - middle of hook
 • III - base of hook
  
Type II
 Body of hamate fx   • IIA - coronal
 • IIB - transverse
 
 
Imaging
  • Radiographs 
    • recommended views
      • PA
      • lateral
      • ER oblique
      • carpal tunnel
        • best view to see hook of hamate fracture
    • findings
      • PA view
    •  
      •  
        • absence of eye sign or cortical ring
          • normally produced by intact hook
        • sclerosis in region of the hook
  • CT
    • indications 
      • establish diagnosis if radiographs are negative    
Treatment
  • Nonoperative
    • immobilization 6 weeks
      • indications
        • acute hook of hamate fractures
        • body of hamate fx (rare)
  • Operative
    • excision of hamate fracture fragment
      • indications
        • chronic hook of hamate fxs with non-union
    • ORIF
      • indications
        • ORIF is possible but has little benefit
Complications
  • Non-union
  • Scar sensitivity
  • Iatrogenic injury to ulnar nerve
  • Closed rupture of the flexor tendons to the small finger 
 

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Questions (8)
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(SBQ07SM.40) A 44-year-old man presents with ulnar-sided right wrist pain and mild constant tingling in the fourth and fifth digits after injuring his wrist while playing golf. Although pain and function have improved with conservative treatment 6 months following the injury, he still reports difficulty with his golf game. Which of the following should initially be obtained in this patient to aide in the diagnosis? Review Topic

QID: 1425
1

Bone scan of the wrist and hand

1%

(13/1978)

2

EMG study of the affected extremity

16%

(311/1978)

3

Carpal tunnel view radiograph

75%

(1477/1978)

4

CT scan of the distal forearm and wrist

4%

(78/1978)

5

Contrast enhanced magnetic resonance angiogram

4%

(87/1978)

ML 2

Select Answer to see Preferred Response

PREFERRED RESPONSE 3
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(OBQ08.23) A professional baseball player develops acute hand pain after fouling off a pitch. He is tender over the hypothenar eminence and has paresthesias in the ring and small fingers. Which radiographic view is most likely to reveal the pathology? Review Topic

QID: 409
1

PA wrist

2%

(46/2550)

2

AP wrist in ulnar deviation

4%

(108/2550)

3

Lateral wrist

5%

(123/2550)

4

Carpal tunnel

88%

(2251/2550)

5

Scaphoid

0%

(11/2550)

ML 1

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PREFERRED RESPONSE 4

(OBQ11.130) A 24-year-old racquetball player presents after accidentally striking his racket against the wall during a match two months ago. He is tender to palpation over the hypothenar mass, and his pain is aggrevated by grasping. A radiograph and CT scan of his wrist are shown in Figures A and B. Which of the following treatment methods has been definitively shown in the literature to have a favorable outcome, and a high chance to return to pre-injury activities in patients with this injury? Review Topic

QID: 3553
FIGURES:
1

Activity restriction and continued monitoring

3%

(114/3318)

2

Open reduction and internal fixation

3%

(111/3318)

3

Casting for 6 weeks, followed by physical therapy

6%

(197/3318)

4

Corticosteroid injection and immediate return to play

0%

(11/3318)

5

Surgical excision

86%

(2868/3318)

ML 1

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PREFERRED RESPONSE 5

(OBQ04.21) A 24-year-old professional baseball outfielder reports persistent pain in the hypothenar region when batting for the past year. His CT scan is shown in Figure A. What is the recommended treatment? Review Topic

QID: 132
FIGURES:
1

pisiform excision

2%

(37/1962)

2

hook of hamate excision

92%

(1804/1962)

3

carpal tunnel release

0%

(6/1962)

4

decompression of Guyon's canal

0%

(9/1962)

5

open reduction and internal fixation

5%

(90/1962)

ML 1

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PREFERRED RESPONSE 2
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CASES (1)
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