Mechanical comparison of different plate-and-screw configurations for repairing forearm diaphysis fractures: a systematic review.

PURPOSE: This is the first systematic review of all studies that adjusted plate and/or screw variables to determine the most mechanically stable implant configuration for forearm fracture repair.

METHODS

PubMed and Scopus archives were searched using the phrase “biomechanics” AND “fracture” AND “plate” AND (“forearm” OR “radius” OR “ulna”). Eligibility criteria were applied: (i) studies that mechanically analyzed implant performance by modulating plate and/or screw variables, such as plate geometry, plate material, screw number, etc.; (ii) forearm diaphysis “shaft” fractures of the radius and/or ulna; (iii) studies published at any time; (iv) English language studies.

RESULTS

There were 34 eligible papers. There was greater mechanical stability for these configurations: (i) plates used alone or double-stacked; (ii) plates that were longer, wider, thicker, straight or curved at the bottom, non-ribbed at the bottom, and/or non-grooved at the sides; (iii) plates made of material with higher elastic modulus; (iv) plates that were locking; (v) plates not elevated above bone; (vi) plates affixed to the anterior side of bone; (vii) screws that were longer, thicker, and/or numerous. There was a range of numerical outcomes: (i) interfragmentary motion; (ii) peak stress in cortical bone or plates; (iii) cortical bone stress under the plate to assess bone “stress shielding”; (iv) fatigue life; (v) stiffness; (vi) strength. General observations, implant variables, bone factors, applied loads, outcome metrics, and clinical recommendations are discussed.

CONCLUSIONS

Mechanical analysis can help design, analyze, or use forearm fracture plate-and-screw implants so they providegreater mechanical stability.