Age / Sex : 22 / M

Stress fracture of the hamate hook

Discussion

Findings:

1)     X-ray : diffuse sclerosis of the hamate hook

2)     MRI: diffuse hyperintensity at the hamate hook and body on fat-suppressed axialT2WI

     Incomplete transverse hypointense line at the hamate hook base

3)     CT: incomplete vertical radiolucent cleft at the hamate hook base with surrounding sclerosis

Diagnosis:  Stress fracture of the hamate hook

Discussion: Hamate fracture

1.     Type 1 fracture :

A.     involving the hook of the hamate

B.     most common

C.     etiology:

                         i.         Stress fracture: by repeated microtrauma to the hook during sports involving swing clubs, bats, or racquets, usually in non-dominant hand, about 1/3 of hamate fracture

                        ii.         Direct trauma:: when the butt of the cloub rests on the hamate and the forces of the wring is transmitted directly to the bone

                       iii.         Indirect trauma: by muscular and ligamentous attachments

2.     Type 2 fracture

A.     involving the hamate body

B.     less common

C.     always by direct force, with a punch-press injury or dorsopalmar compression of the wrist between heavy weights

References:

1.     Guha AR, Marynissen H. Stress fracture of the hook of the hamate. Br J Sports Med 2002;36:224-225

2.     Welling RD, Jacobson JA, Jamadar DA, et al. MDCT and radiography of wrist fractures: radiographic sensitivity and fracture patterns. AJR Am J Roentgenol. 2008 Jan. 190(1):10-6.

3.     Amy Powell et al.; http://emedicine.medscape.com/article/97813-overview; Updated: May 09, 2013

4.     Hirano K, Inoue G. Classification and treatment of hamate fractures. Hand Surg. 2005; 10(2-3):151-7