Locking Plates: Do They Prevent Complications?
Gruber and coworkers also compared two types of fixation for a first metatarsocuneiform arthrodesis: a dorsomedial locking plate with a lag screw and crossed screws. Each group consisted of five cadaveric limbs. The researchers found no difference in rigidity between the two groups.24
What Other Studies Reveal About Locking Plates
Granata and colleagues studied the locking plate fixation success of the talonavicular joint.25 The authors analyzed two lag screws in seven cadaveric limbs versus one lag screw and a locked compression plate in six cadaveric limbs. In their biomechanical model, a dorsal locked compression plate with one retrograde screw was more effective at limiting the 3D motion across the talonavicular joint in comparison with the traditional construct of two lag screws.25
Abbasian and colleagues analyzed three types of fixation for a calcaneal osteotomy: a lateral locking plate, a headless screw or a headed screw.26 In 67 osteotomies, 17 had fixation using a headed screw, 18 received a headless screw and the remaining 32 had lateral plate fixation. Overall, 47 percent of the headed screws, 11 percent of the headless screws and 6 percent of the lateral plates required removal to address symptoms that physicians suspected were due to the hardware. There was a 10 percent rate of wound complications in the lateral plate cohort. The incidences of local wound complications and radiological delayed union were higher in the group fixated with lateral locking plates. There was no significant difference in union rate among the three types.
In an analysis of locking plates on calcaneal fractures, Hyer and colleagues performed a two-year retrospective analysis of 17 calcaneal fractures treated with locking plates.27 Weightbearing began at approximately four to five weeks. Serial radiographic analysis occurred throughout the two years of the study. The authors concluded that early weightbearing could begin in patients with calcaneal fractures if surgeons employed locking plates for the fractures.
Blake and coworkers performed a biomechanical analysis of a locking and a non-locking plate on a cadaveric calcaneal fracture model.28 Surgeons created a Sanders IIB type calcaneal fracture in 10 matched pairs of cadaveric calcanei. Each pair had fixation with the same calcaneal reconstruction plate using either locking or non-locking screws in the same hole pattern. Specimens had axial loading for 1,000 cycles through the talus followed by load to failure. Statistical comparisons occurred between the locking and non-locking constructs on the displacements during cyclic loading as well as construct stiffness and load achieved at selected fragment displacements. Researchers found no mechanical advantage to locking technology for calcaneal fractures in their model.
Redfern and coworkers also compared a locking plate and non-locking plate for calcaneal fractures in five cadaveric limbs each.29 In a cadaver model of Sanders type IIB calcaneal fractures, locking plate fixation did not provide a biomechanical advantage over traditional non-locking plate fixation.
Eckel and colleagues analyzed four different lateral plate constructs for distal fibula fractures.30 Researchers divided 40 fresh frozen lower extremities into four groups. Simulating Weber B distal fibula fractures with an osteotomy, the study authors stabilized the fracture with one of four plate systems: a standard one-third tubular plate with an interfragmentary lag screw; a locked compression plate with a lag screw; a low-profile locking plate with a lag screw; or a non-locking plate. Researchers applied controlled monotonic bending and cyclic torsional loading, and quantified bending stiffness, torsional stiffness and fracture site motion. They found no significant differences in plate performance.