J of Evolution of Med and Dent Sci/ eISSN- 2278-4802, pISSN- 2278-4748/ Vol. 3/ Issue 12/ Mar 24, 2014 Page 3114
ISOLATED TRANSVERSE FRACTURE OF THE BODY OF THE HAMATE BONE:
A RARE CASE REPORT
Prasanna C1, Arvind Kumar S. M2
HOW TO CITE THIS ARTICLE:
Prasanna C, Arvind Kumar S. M. Isolated Transverse Fracture of the Body of the Hamate bone - A Rare Case Report. Journal of Evolution of Medical and Dental Sciences 2014; Vol. 3, Issue 12, March 24; Page: 3114-3118, DOI: 10.14260/jemds/2014/2252
ABSTRACT: Carpal bone fractures make up a significant proportion of injuries to the wrist. The complex bone shape and articulations make diagnosis more difficult and missed injuries more common. The scaphoid is the most commonly fractured carpal bone. Estimates suggest hamate fractures constitute 2% of all carpal fractures. The hamate bone is a roughly triangular-shaped bone composed of both a body and a hook. Hamate fractures are thus classified as type I fractures involving the hook and type II fractures involving the body. Type I fractures are more common than type II fractures. Hamate fractures are seen more often as a sports injury. Transverse fractures of the body are even very rare and are usually seen in association with perilunate dislocation. Isolated transverse body fracture of the hamate is not reported in the literature. We present a case of isolated transverse body fracture of the hamate as a result of farm injury.
KEYWORDS: Transverse Fracture, Hamate Body, Direct Impact.
INTRODUCTION: Hamate fractures consist of either hook fractures or body fractures. They represent 2% to 4% of carpal fractures.1-3 The hook fractures usually result from a direct blow on an outstretched hand or from an indirect injury during gripping of an object such as a baseball bat, golf club, or tennis racquet.4-6 Fractures of the hook are more common than those of the body. Fractures of the hamate body are one of three types: direct blows to the hamate cause non displaced body fractures with varying amount of comminution; axial load to the fifth and or fourth metacarpal causes a dorsal fracture dislocation of the carpo-metacarpal joint, producing a coronal dorsal hamate fracture; transverse fractures occur as part of the injury pattern of a perilunate fracture dislocation.1,3,7,8 Isolated transverse fracture of the body is very rare and to the best of our knowledge, has not been reported in the literature. Here we present a case of transverse fracture of the hamate body in a middle aged male.
CASE REPORT: A 29 year old farmer fell from his tractor and sustained injury to his non dominant left wrist. He had an open wound over the volar aspect of his left wrist, which was managed with wound dressings at a primary hospital. A month later he reported to a physician, who after seeing his radiographs (Fig. 1) referred it to an orthopedic surgeon. The patient presented to us with complaints of pain in his left wrist. Pain was present typically with lifting any weights thus preventing him from doing his agricultural activities.
J of Evolution of Med and Dent Sci/ eISSN- 2278-4802, pISSN- 2278-4748/ Vol. 3/ Issue 12/ Mar 24, 2014 Page 3115 The hand grip strength was fairly normal and the wrist range of movements was almost full. The hook of hamate pull test was negative. No neurovascular deficits were elicited. The radiographs revealed a transverse fracture of the body of the hamate bone, with no other bony injury. The patient was not treated for the fracture till the time of presentation apart from the wound care. Since, there were no other associated injuries; it was decided to manage conservatively. The patient was put on below elbow plaster cast with wrist in neutral position. Plaster cast was removed after a month and clinical assessment showed no tenderness.
The fracture line however was still visible (Fig. 2) in the radiographs. The patient was advised to continue the cast support for a month, but he denied the same. He was advised not to lift any weights in his left hand. He returned to the clinic, six months following the initial trauma, by which time he was doing all his routine activities without any difficulty. Local examination showed no tenderness and the radiographs taken showed fracture union (Fig. 3, 3a) with a minimal gap on the lateral aspect.
DISCUSSION: The hamate is a triangular bone located in the distal carpal row and abuts the metacarpals of the little finger and ring finger. Hamate fractures mainly occur in two locations - the hook of the hamate or the body. Fractures of the hook are more common than those of the body and are usually a result of a sports injury.9 Fractures of the hamate body are less common and can be associated with 5th or sometimes 4th metacarpal fractures or axial fracture dislocation.9-13 Milch14 classified hamate fractures into 2 groups, the first involving the body of the bone and the second involving the hamular process or the hook of the hamate.
He divided the hamate body fractures into 2 subgroups: those in which the fracture line passes ulnar to the hook and those with fractures radial to the hook.12,14 The less common coronal body fracture pattern, dorsal flake fracture, and fractures involving various articular surfaces that are not included in this original classification have been reported in the literature.9-11,13 Though transverse fracture through the body of hamate has been described, they are commonly seen in association with perilunate dislocations. An isolated transverse fracture of the body is not reported.
The most common mechanism of injury in carpal bone fractures is an axial compression force applied with the wrist in hyperextension. This usually causes scaphoid waist fracture when the wrist is hyperextended past 95° and radially deviated by 10°.9 Additional radial or ulnar deviation at that moment causes different types of injuries. Thomas and Birch13 reported that compression in ulnar deviation with palmar flexion causes a coronal hamate body fracture, when the hamate abuts against the triquetral and a force directed through the metacarpals splits the hamate coronally. If the wrist is in radial deviation, the force causes sagittal fracture in the hamate.13 The mechanism of injury in our patient was a direct blow to the ulnar aspect of the wrist as he landed on a stone.
J of Evolution of Med and Dent Sci/ eISSN- 2278-4802, pISSN- 2278-4748/ Vol. 3/ Issue 12/ Mar 24, 2014 Page 3116 The fracture as such was missed because of the open wound and delay in obtaining an expert opinion by the patient. Fractures of the hamate body can be non-operatively treated with casting unless displacement is significant. This fracture was extra-articular and had no major displacements or other associated injuries. Hence the patient was managed conservatively. Patient made an uneventful recovery, even though radiology showed a gap on the radial aspect.
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4. Carter PR, Eaton RG, Littler JW. Ununited fracture of the hook of the hamate. J Bone Joint Surg1977; 59A:583-588.
5. Foucher G, Schuind F, Merle M et al. Fractures of the hook of the hamate. J Hand Surg 1985; 10 B: 205-210.
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10.Jones BG, Hems TE. Simultaneous fracture of the body of the hamate and the distal pole of the scaphoid. J Trauma. 2001; 50(3):568-570.
11.Roche S, Lenehan B, Street J, O’Sullivan M. Fourth metacarpal base fractures in association with
coronal hamate fracture. Injury Extra. 2005; 36(8):316-318.
12.Fakih RR, Fraser AM, Pimpalnerkar AL. Hamate fracture with dislocation of the ring and little finger metacarpals. J Hand Surg Br. 1998; 23(1):96-97.
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J of Evolution of Med and Dent Sci/ eISSN- 2278-4802, pISSN- 2278-4748/ Vol. 3/ Issue 12/ Mar 24, 2014 Page 3117 FOOT NOTES OF FIGURES:
Fig. 3: Anteroposterior and lateral views of the left wrist at six months showed fracture healing
with a minimal gap seen in the radial side
Fig. 3a: Magnified view of the area marked Fig. 2: Anteroposterior view
of the left wrist 2 months after injury, still showing the fracture line
Fig. 1: Anteroposterior view of the left wrist showing a clear fracture line in the body of the hamate bone
Fig. 1a: Clinical photograph of the involved hand at the time of presentation showing the
J of Evolution of Med and Dent Sci/ eISSN- 2278-4802, pISSN- 2278-4748/ Vol. 3/ Issue 12/ Mar 24, 2014 Page 3118
AUTHORS:
1. Prasanna C. 2. Arvind Kumar S. M.
PARTICULARS OF CONTRIBUTORS:
1. Assistant Professor, Department of Orthopaedics, PSGIMS & R, Peelamedu, Coimbatore.
2. Associate Professor, Department of Orthopaedics, PSGIMS & R, Peelamedu, Coimbatore.
NAME ADDRESS EMAIL ID OF THE CORRESPONDING AUTHOR:
Dr. Prasanna C,
Assistant Professor of Orthopaedics, PSGIMS and R,
Peelamedu, Coimbatore - 641004. E-mail: prasannapgi@hotmail.com
