Metacarpal Neck Fractures: A Review of Surgical Indications and Techniques

Abstract

Context: Hand injuries are a common emergency department presentation. Metacarpal fractures account for 40% of all hand fractures and can be seen in the setting of low or high energy trauma. The most common injury pattern is a metacarpal neck fracture. In this study, the authors aim to review the surgical indications for metacarpal neck fractures, the fixation options available along with the risk and benefits of each.

Evidence acquisition: Literature review of the different treatment modalities for metacarpal neck fractures. Review focuses on surgical indications and the risks and benefits of different operative techniques.

Results: The indications for surgery are based on the amount of dorsal angulation of the distal fragment. The ulnar digits can tolerate greater angulation as the radial digits more easily lose grip strength. The most widely utilized fixation techniques are pinning with k-wires, dorsal plating, or intramedullary fixation. There is currently no consensus on an optimal fixation technique as surgical management has been found to have a complication rate up to 36%. Plate and screw fixation demonstrated especially high complication rates.

Conclusions: Metacarpal neck fractures are a common injury in young and active patients that results in substantial missed time from work. While the surgical indications are well-described, there is no consensus on the optimal treatment modality because of high complication rates. Dorsal plating has higher complication rates than closed reduction and percutaneous pinning, but is necessary in comminuted fractures. The lack of an ideal fixation construct suggests that further study of the commonly utilized techniques as well as novel techniques is necessary.

Keywords: Bone Wires; Fracture Fixation, Internal; Hand; Metacarpal Bone; Neck Fractures.

Figure 1.. Fight Bite Sustained With Metacarpal Neck Fracture

Figure 2.. Note the Altered Contour and Deformity of the Fifth Small Finger ray Along the Border due to an Underlying Angulated Metacarpal Neck Fracture

Figure 3.. Note the Rotational Deformity due to an Underlying Spiral Metacarpal Fracture

Rotational deformity is most accentuated with active or passive finger flexion, while angular deformity is most prominent with finger extension.

Figure 4.. Radiographic Assessment of Metacarpal Neck Fractures, Note the Dorsal Angulation

A, B and C, PA, lateral, and oblique X-rays demonstrating displaced, dorsally angulated fifth metacarpal neck fracture; D, measurement of dorsal angulation between the line along the longitudinal axis of the metacarpal shaft (medullary canal) and the line from the center of the metacarpal head to the fracture site; E, measurement of dorsal angulation between the two lines tangential to the dorsal cortices of the proximal and distal fragments using the intersecting angle between the two lines as the measure of the fracture angulation.

Figure 5.. Radiographic Assessment of Metacarpal Neck Fracture After Reduction and Cross-pinning

A and B, PA and lateral X-rays demonstrating cross-pinning construct showing reduction of the metacarpal neck fracture.

Figure 6.. Crucifix Pinning Showing Reduction of the Metacarpal Neck Fracture by Two-crossed Pins

Figure 7.. Bouquet Pinning Showing Reduction of the Metacarpal Neck Fracture by Three Antegrade Pins

Figure 8.. Plate and Screw Fixation of Metacarpal Neck Fracture

Figure 9.. Intramedullary Fixation of Metacarpal Fractures With Commercially Available Nails Placed Antegrade

Later removal is required, (Courtesy Jorge Orbay, MD).

Figure 10.. Fluoroscopic Assessment of Metacarpal Neck Fracture Treated by Reduction and Intramedullary Fixation With a Headless Compression Screw

A and B, Intramedullary fixation with a headless compression screw is best indicated for neck and not shaft fractures, the technique requires exposure of the metacarpal head through a split in the extensor mechanism; C, D and E, the fracture is reduced and the guidewire is directed retrograde through the metacarpal head. Since the fracture typically flexes, the guidewire should be placed slightly volar in the metacarpal head as it is directed into the shaft, thereby aiding in reduction of the fracture by extending the fracture as the screw is inserted; F, the headless compression screw is then passed over the guidewire. The length of the screw should be measured so that it ends in the isthmus of the fracture and not the base in order to obtain good fixation while avoiding over-correction of the normal bow of the metacarpal; G, H and I, adequate reduction is held by one of these headless compression screws.