Accuracy of fluoroscopic examination in the treatment of Bennett’s fracture

Abstract

Background Restoration of joint congruity is an important factor for the prevention of subsequent arthritis in patients with Bennett’s fracture. Surgical treatment of Bennett’s fracture is thus generally recommended for displaced intra-articular fractures to the proximal aspect of the thumb metacarpal. Fluoroscopic examination is used to evaluate the adequacy of closed reduction after pinning of Bennett’s fracture. The purpose of this study was to determine the accuracy of fluoroscopy to determine the reduction of Bennett’s fractures. Methods A model was created, to mimic a Bennett’s fracture utilizing ten fresh-frozen cadaveric hands. An oblique cut was made in the proximal aspect of the thumb metacarpal using an oscillating saw. The small oblique fragment involved 1/4–1/3 of the joint surface was then shifted in position creating a step-off or gap at the fracture site. An anatomical reduction model, gap models (1 mm, 2 mm, 3 mm), and step-off models (1 mm, 2 mm, 3 mm) were created using percutaneous fixation with two 1.0 mm Kirschner wires for each cadaveric hand. Fluoroscopic assessment then took place and was reviewed by 2 attending hand surgeons blinded to the actual position. Their estimated fluoroscopic position was then compared to the actual displacement. Results The step-off and gap on fluoroscopic examination showed a significant difference compared to the step-off and gap from direct visualization. The frequency of underestimation for the 3 mm displacement models from the fluoroscopic examination was 60%. The frequency for overestimated was 9% for the models in which displacement was within 2 mm (0, 1, 2 mm). Conclusions The assessment of articular gap and step-off using PA (postero-anterior), AP (antero-posterior), and lateral view of fluoroscopic examination is not accurate as compared to the examination by direct visualization. Surgeons need to be aware that PA, AP and lateral view of fluoroscopic examination alone may not be sufficient to judge the final position of a reduced Bennett’s fracture. Other methods such as live fluoroscopy in multiple different planes, 3-dimensional fluoroscopy or arthroscopic examination should be considered.

Arthroscopic Assistance and Percutaneous Fixation of Complex Intraarticular Metacarpophalangeal Fracture

“…This article presents an arthroscopic assistance technique for minimally invasive anatomic reduction and percutaneous fixation of complex intraarticular fractures of the MCP joint which often involves severe compromise of the joint surface and overall hand function due to the sequelae stiffness affecting the joint. 7 Frequently, the reduction achieved by fluoroscopy is suboptimal resulting in persistent pain or articular stiffness, 20 which often requires arthrodesis to achieve a stable and painless joint. The magnification achieved by arthroscopic direct visualization allows a better evaluation of the fracture, enabling adequate management of the bone fragments to achieve anatomical reduction and definitive stabilization/fixation.…”

Bennett Fracture

“…The PA, AP and lateral projections in a fluoroscopic examination may not be sufficient to determine the final position of a reduced Bennett fracture, as surgeons should be aware. The use of arthroscopic examination, three-dimensional fluoroscopy or live fluoroscopy should also be considered (18).…”

Treating Little Finger’s Flexor Profundus Tendon Rupture after Percutaneous K-wire Fixation of a Bennet Fracture – A Case Report

“…About 20% of all fractures in the human skeleton involve the hand, affecting primarily the young and active population [ 1 ]. The Bennett’s Fracture (BF) is an intra-articular injury that occurs at the proximal aspect of the thumb metacarpal and is the most common fracture involving the carpometacarpal joint [ 2 ]. There is still controversy around the best treatment option.…”

“…No consensus has been reached regarding the long-term clinical benefits of an anatomic reduction, although it seems that articular step-offs exceeding 2 mm can lead to malunion and consequently joint subluxation and arthritis [ 1 , 3 ]. Surgical management is generally advocated and popular surgical techniques include close reduction and fixation with Kirschner wires (K-wire) or open reduction and internal fixation, with screws and/or plates, often followed by cast immobilization [ 2 , 3 ]. Although it is a popularized technique, K-wire complications are not uncommon.…”