Comparison of the size of plates for fracture fixation with the size of phalanges and metacarpals in cadavers of Asian origin

Anatomic Assessment of K-Wire Trajectory for Transverse Percutaneous Fixation of Small Finger Metacarpal Fractures: A Cadaveric Study

BACKGROUND

The purpose of this cadaveric study is to evaluate the trajectory of percutaneous transverse Kirschner wire (K-wire) placement for fifth metacarpal fractures relative to the sagittal profile of the fifth metacarpal in order to develop a targeting strategy for the treatment of fifth metacarpal fractures.

METHODS

Using 12 unmatched fresh human upper limbs, we evaluated the trajectory of percutaneous transverse K-wire placement relative to the sagittal profile of the fifth metacarpal in order to develop a targeting strategy for treatment of fifth metacarpal fractures. The midpoint of the small and ring finger metacarpals in the sagittal plane was identified at 3 points. At each point, a K-wire was inserted from the small finger metacarpal into the midpoint of the ring finger metacarpal ("center-center" position).

RESULTS

The angle of the transverse K-wire relative to the table needed to achieve a center-center position averaged 20.8°, 18.9°, and 16.7° for the proximal diaphysis, middiaphysis, and the collateral recess, respectively. Approximately 80% of transversely placed K-wires obtained purchase in the long finger metacarpal.

CONCLUSIONS

These results can serve as a guide to help surgeons in the accurate placement of percutaneous K-wires for small finger metacarpal fractures and may aid in surgeon training.

Ring and little finger metacarpal fractures: mechanisms, locations, and radiographic parameters

PURPOSE

To describe a series of ring and little finger metacarpal fractures with regard to mechanism, location, midshaft diameter, and isthmus diameter, to better define injury patterns and assist the surgeon in selection of appropriately sized implants.

METHODS

We reviewed all metacarpal fractures in skeletally mature patients who presented to a single surgeon over a 2-year period. Fractures of the ring and little finger metacarpals were analyzed with regard to mechanism and fracture location. Metacarpal midshaft and minimum isthmus diameters were measured on posteroanterior radiographs.

RESULTS

A total of 101 fractures involved the ring and little finger metacarpals. Punching-type injuries accounted for most fractures in the little finger metacarpal (49 of 67) and ring finger metacarpal (26 of 34). Among these punching-related ring and little finger metacarpal fractures, the most common fracture location was the little finger metacarpal neck (34 of 75), followed by the ring finger metacarpal shaft (21 of 75). Among men in this series, the metacarpal midshaft and minimum isthmus diameters were significantly narrower in the ring finger metacarpal than in the little finger (7.4 vs 8.7 mm, p < .001; and 2.2 vs 3.8 mm, p < .001).

CONCLUSIONS

Whereas punching injuries tended to cause neck fractures in little finger metacarpals in this series, they caused shaft fractures in ring finger metacarpals, which may thus be considered a variant boxer's fracture. Furthermore, in men with fractures, the ring finger metacarpal is significantly narrower than the little finger, both in midshaft diameter and isthmus diameter, which surgeons should consider when planning internal fixation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Experience with a new ultralow-profile osteosynthesis system for fractures of the metacarpals and phalanges

Current osteosynthesis systems for the hand generally recommend thicker plates for metacarpal than for phalangeal fractures. We report a prospective review of 20 hand fractures treated with a new plating system in which 0.6-mm-profile-height plates are used for both metacarpals (11 cases) and phalanges (9 cases). After a follow-up period ranging from 6 to 24 months, there were 8 excellent, 7 good, and 2 poor results (American Society for Surgery of the Hand criteria), with no incidence of plate failure. These outcomes were compared with a matched cohort of 20 similar fractures treated with the widely used Stryker-Leibinger system. We found no significant differences in ranges of motion or complications between the 2 groups. The new plating system was technically straightforward to use and equally effective. Use of the thinner microplates for metacarpal fractures was not associated with any untoward outcomes.