Evaluation Of Therapeutic Strategies In Hook Of Hamate Fractures
Oliver Scheufler, M.D., Reimer Andresen, M.D., Sebastian Radmer, M.D., Detlev Erdmann,
M.D., Günter Germann, M.D., Ph.D.
Fractures of the hamate hook are rare events, making up only 2-4% of all carpal fractures.
They may occur by different mechanisms, including a directly applied force in a fall or crush
injury, a shearing force applied by the extrinsic flexor tendons of the ring and small finger,
repeated microtrauma during forceful grip in several sports using a racquet or bat, and
combinations of these forces 1. Although these fractures are uncommon, the increasing
popularity of golf and other racquet sports has led to a higher incidence of stress fractures of
the hamate hook. Approximately one third of these stress fractures are caused by golf 2.
Clinical signs of hamate hook fractures include pain in the ulnar palm aggravated by grasp
and dorsoulnar deviation, pain with deep palpation over the hook, and painful flexion of the
ring and small finger caused by tendinitis of the finger flexors. Clinical diagnosis is confirmed
by standard and special radiographs, CT, and MRI, but is often delayed when patients seek
medical attention only after symptoms persist 3. Hook of hamate fractures can be treated
conservatively or operatively. Some advocate conservative treatment by lower arm splinting
as the treatment of choice in nondisplaced fractures 4, while others believe that fragment
healing is the exception and nonunion the rule with conservative treatment 5. Displaced
fractures should be treated operatively, whereby excision of the fragment or open reduction
and internal fixation (ORIF) are described.
A hamulus ossis hamati fracture was verified in 14 patients (mean age: 42 years; range: 21 73 years) including 11 males and 3 females (Table I). In 11 patients (78.6%) hamate hook
fractures resulted from a direct blow to the proximal part of the palm during different daily
activities. In 3 patients (21.4%) stress fractures occurred during sports activities, involving the
nondominant hand while swinging a golf club in 2 patients and the dominant hand while
swinging a tennis racquet in 1 patient. Diagnostic imaging included conventional radiographs
in two planes in all of the 14 patients, carpal tunnel view in 7 patients (50%), CT scan in 9
patients (64.3%), and MRI in 5 patients (35.7%). All patients presented a fracture of the hook
close to the base.
In 6 patients (42.9%) conservative treatment was initiated immediatly after trauma with a
lower arm cast for 6 weeks, in 5 patients (35.7%) the fragment was excised primarily, and in 3
patients (21.4%) an ORIF was performed primarily using a screw. 5 of the 6 patients (83.8%)
treated conservatively developed nonunion of the fracture with persisting clinical symptoms.
All of those patients were operated secondarily, whereby 3 patients underwent excision and 2
patients ORIF with screw fixation. All surgical treatments included release of Guyon´s canal.
The group of patients undergoing excision received functional treatment with
physiotherapeutic exercises without any limitation of movement. The patients undergoing
ORIF were immobilized with a lower arm cast for 2 weeks followed by physiotherapy and
were instructed to avoid any strain of the injured hand for a total of 6 weeks. All 8 patients
operated primarily were asymptomatic three months after surgery. In all 5 cases of secondary
surgery after failed conservative treatment elemination of symptoms was achieved.
The clinical outcome of patients treated conservatively was disappointing. Therefore, primary
surgical treatment is recommended. In our patients excision and ORIF led to comparable
results. Important considerations in the choice of treatment for hamate hook fractures are the
time of diagnosis, hook displacement, and vascularity of the fragment 6. Other important
considerations are lifestyle and working requirements, because conservative treatment
requires a long time of immobilization with subsequent physiotherapy and a high risk of
nonunion, and fragment excision has been associated with weakened grasp, impaired
sensibility, and residual pain with considerable frequency. ORIF, employing a compression
screw of proper size, may be advantageous in several ways. It allows exact repositioning of
the fracture and restitution of the complex anatomic structures linked to the hamate hook. It
also reestablishes the hamate hook as a pulley for flexor tendon function of the small and ring
finger, especially in ulnar deviation and power grip, thereby restoring hand function 7.
1. Walsh, J. J, 4th, Bishop, A. T. Diagnosis and management of hamate hook fractures:
Hand Clin. 16: 397, 2000.
2. Guha, A. R., Marynissen, H. Stress fracture of the hook of the hamate. Br J. Sports Med.
36: 224, 2002.
3. Andresen, R., Radmer, S., Scheufler, O., Banzer, D. Imaging and therapy of hamulusossis-hamati fracture. Röntgenpraxis 54: 114, 2001.
4. Whalen, J. L., Bishop, A. T., Linscheid, R. L. Nonoperative treatment of acute hamate
hook fractures. J. Hand Surg. [Am] 17: 507, 1992.
5. David, T. S., Zemel, N. P., Mathews, P. V. Symptomatic, partial union of the hook of the
hamate fracture in athletes. Am. J. Sports Med. 31: 106, 2003.
6. Failla, J. M. Hook of hamate vascularity: vulnerability to osteonecrosis and nonunion. J.
Hand Surg. [Am] 18: 1075, 1993.
7. Demirkan, F., Calandruccio, J. H., Diangelo, D. Biomechanical evalutation of flexor
tendon function after hamate hook excision. J. Hand Surg. [Am] 28: 138, 2003.
Table I. Patients with Hook of Hamate Fractures
Pat.
Age
Sex
Fracture
Trauma
Initial
Secondary
Treatment
Treatment
1
24
male
nondisplaced
hockey bat contusion
conservative
excision
2
56
male
nondisplaced
car door contusion
conservative
excision
3
67
male
nondisplaced
stress fracture (golf player)
conservative
excision
4
42
female
nondisplaced
bicycle accident
conservative
none
5
29
male
nondisplaced
fall
conservative
screw
6
35
male
displaced
bicycle accident
conservative
screw
7
51
male
nondisplaced
stress fracture (tennis)
excision
-
8
73
male
nondisplaced
stress fracture (golf)
excision
-
9
22
male
displaced
bicycle accident
excision
-
10
62
female
displaced
bicycle accident
excision
-
11
31
female
nondisplaced
fall
excision
-
12
21
male
nondisplaced
motorcycle accident
screw
-
13
24
male
nondisplaced
fall from roof
screw
-
14
51
male
nondisplaced
fall
screw
-
Fig. 1a
Fig. 1b
Fig. 1 Patient no. 14 with nondisplaced hook of hamate fracture in the right hand: standard
radiograph in anteroposterior projection, b) axial CT scan
Fig. 2a
Fig. 2b
Fig. 2 Patient no. 14 after ORIF with screw fixation of the fragment: a) standard radiograph in
anteroposterior projection, b) lateral projection