management of reverse bennett fracture in universitiy

Authors: Stjepan Ćurić MD, Petra Jurina MD,
Mario Malović MD
* dislocation fracture of the fifth metacarpal base is pathologically
and radiographically similar to the Bennett’s fracture of the thumb
metacarpal, and is referred to as a „Reversed Bennett” or „Baby
Bennett”
* in the thumb (Bennett's fracture), the abductor pollicis longus acts
as a distracting force, producing subluxation and proximal
migration of fractured element
* in the small finger (Reversed Bennett's
fracture), the extensor
carpi ulnaris has the same behaviour as the abdcutor pollicis
longus
Figure 1: Radiographic imaging of patient with Reversed Bennett’s fracture
* data was gathered from Hospital Informatic System (BIS)
* in the time period from 2012 to 2014, 78 patients were diagnosed with
Reversed Bennett (65 male, 13 women; 21 – 75 years of age , in the average of
37 years)
* main injury mechanism was fall on the hand (60%)
* indication for surgical treatment was made in 17 patients ( more than 5
degrees of angulation or more than 1mm of dislocation), others were treated
conservatively with casting
* operative treatment included: percutaneous K wiring (9 patients),
fix/mini Herbert screw (6 patients), AO screw (2 patients)
twin
Figure 2: Radiograms of patient with Reversed Bennett’s fracture after
internal fixation with twin fix/mini Herbert
Figure 3: Radiograms of patient with Reversed Bennett’s fracture after
internal fixation AO screw
Figure 4: Radiograms of patient with Reversed Bennett’s fracture after
percutaneous K wiring
100
80
60
40
20
0
MCP flexion(degrees)
MCP extension( degrees)
K wire
Twin fix /mini
Herbert
AO screw
Graph 2: average range of MCP abduction postoperatively and after finished
rehabilitation
2,5
2
1,5
Abduction (cm)
1
0,5
0
K wire
Twin fix/mini Herbert
AO screw
* force acting on the head of the metacarpal causes a metacarpal neck
fracture, but in some cases metacarpal base fracture occurs
* fracture of the fifth metacarpal base was successfully operatively treated
with open reduction and internal fixation
* the debate between closed reduction and casting versus operative
management continues
* instability of intra-articular fractures of the fifth metacarpal base is mainly
due to the strong, unopposed proximal pull of the extensor carpi ulnaris,
which causes ulnar and dorsal subluxation of the main fracture fragment
* surgeon's personal preference should be supported by evidencebased literature, regardless the choice of treatment
* until a large-scale study comparing these 2 treatment
options(surgical treatment or conservatively with casting) is
completed, a surgeon's personal preference will continue to be
acceptable as a standard of care