The Prevalence of Unanticipated Hamate Hook Abnormalities in Computed Tomography Scans: A Retrospective Study

Document Type : RESEARCH PAPER


1 Orthopaedic Hand and Upper Extremity Service, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA

2 Department of Surgery and Perioperative Care, Dell Medical School at the University of Texas at Austin, Austin, TX, USA


 Background:It is possible that some hamate hook fractures are not diagnosed or treated, thereby affecting the study of their natural history. Study of the prevalence of incidental hamate hook fractures, nonunions, and other abnormalities on computed tomography (CT) ordered for another reason could document a subset of undiagnosed and untreated hamate hook fractures which might change our understanding about the natural history.
Methods: Reports of 2489 hand, wrist, and forearm CT scans for hamate hook abnormalities were searched. We excluded 19 patients with anticipated hamate fractures and 1 patient that had a hamate hook excision. Twenty-eight patients had an unanticipated hamate hook abnormality.
Results: There was a significant difference in the prevalence of incidental hamate hook abnormalities by sex but not by age. Among the 28 unexpected hamate hook abnormalities, there were 16 fractures of the base (12 acute, 1 nonunion, and 3 of uncertain age), 5 acute oblique fractures, and 7 tip abnormalities/ossicles. The patient with an incidental nonunion had a CT scan for wrist pain and was diagnosed with gout.
All fractures involved a direct blow to the hand (distal radius or scaphoid fracture, or crush injury). The 7 patients with a hamate tip abnormality had a CT scan for a distal radius or metacarpal fracture, crush injury or wrist pain. Five acute fractures were treated operatively with excision and the other 23 fractures were treated nonoperatively.
Conclusion: Hamate fractures can be diagnosed incidental to other hand and wrist problems on CT.


Main Subjects

1. Stark HH, Jobe FW, Boyes JH, Ashworth CR. Fracture of
the hook of the hamate in athletes. J Bone Joint Surg
Am. 1977; 59(5):575-82.
2. Geissler WB, Slade JF. Fractures of the carpal bones.
In: Wolfe SW, Pederson WC, Hotchkiss RN, Kozin SH,
editors. Green’s operative hand surgery: the pediatric
hand. 6th ed. Philadelphia, PA: Elsevier Health Sciences;
2010. P. 639-708.
3. Gardner S, Ruchelsman D, Mudgal C. Concomitant
high-energy fractures of the distal radius and hook of
hamate. J Hand Surg Eur Vol. 2012; 37(4):366-7.
4. Parker RD, Berkowitz MS, Brahms MA, Bohl WR. Hook
of the hamate fractures in athletes. Am J Sports Med.
1986; 14(6):517-23.
5. Boulas HJ, Milek MA. Hook of the hamate fractures.
Diagnosis, treatment, and complications. Orthop Rev.
1990; 19(6):518-29.
6. Failla JM. Hook of hamate vascularity: vulnerability to
osteonecrosis and nonunion. J Hand Surg Am. 1993;
7. Heo YM, Kim SB, Yi JW, Lee JB, Park CY, Yoon JY, et
al. Evaluation of associated carpal bone fractures
in distal radial fractures. Clin Orthop Surg. 2013;
8. Carroll RE, Lakin JF. Fracture of the hook of the hamate:
acute treatment. J Trauma. 1993; 34(6):803-5.
9. Kato H, Nakamura R, Horii E, Nakao E, Yajima H.
Diagnostic imaging for fracture of the hook of the
hamate. Hand Surg. 2000; 5(1):19-24.
10. Pierre-Jerome C, Roug IK. MRI of bilateral bipartite
hamulus: a case report. Surg Radiol Anat. 1998;
11. O’Rahilly R. A survey of carpal and tarsal anomalies. J
Bone Joint Surg Am. 1953; 35-A(3):626-42.