Perpendicular Pull-Out Force of Locking Versus Non-Locking Plates in Thin Cortical Bone Using a Canine Mandibular Ramus Model

Influence of plate type and placement on the immobilization of bilateral equine mandibular osteotomies: Ex vivo study

OBJECTIVE

To determine the influence of plate fixation (locking or dynamic compression) and the site of application (ventral [V] or ventrolateral [VL]) on the resistance to bending of transverse mandibular fractures.

STUDY DESIGN

Ex vivo, simple randomized study.

SAMPLE POPULATION

Mandibles harvested from adult equine cadavers (n = 18).

METHODS

Bilateral osteotomies were created 1 cm caudal to the mental foramen and perpendicular to the long axis of each mandible. Mandibles were fixed with 1 of 3 methods: (1) VL dynamic compression plate (DCP), (2) V-DCP, or (3) VL locking compression plating (LCP). Constructs were mounted on a custom testing jig and tested for resistance in bending by applying force to the rostral aspect of the mandible. Stiffness and change of distance of the dorsal osteotomy at 200 N were compared among constructs.

RESULTS

VL-LCP constructs were 5.25 and 2.42 times stiffer than V and VL constructs, respectively (P<.001). Change in the width of the osteotomy gap at 200 N of load was reduced 6.04 times when osteotomies were stabilized with VL compared to V (P<.001); no difference was detected between the VL and VL-LCP constructs (P=.836).

CONCLUSION

Ventrolateral LCP fixation of equine transverse mandibular osteotomies provided greater resistance to bending compared with V and VL constructs.

CLINICAL SIGNIFICANCE

These results provide evidence to recommend fixation of transverse interdental mandibular fractures with VL-LCP rather than with DCP in horses.

Retrospective evaluation of perioperative and short term clinical outcomes in appendicular long bone skeleton fractures repaired via the string of pearls (SOP) locking plate system

BACKGROUND

Internal plate fixation and, more recently, locking plate fixation are commonly used in the repair of fractures in small animal surgery. This retrospective study reviewed the use of the String of Pearls locking plate system in the fixation/repair of appendicular long bone skeleton fractures in 31 small animal veterinary patients (33 fractures).

RESULTS

Major complications necessitating revision surgery occurred in 7/33 (21%), with implant failure as the inciting cause in all cases. Variables corresponding to an unsuccessful outcome were evaluated, and a correlation was found with plates placed in a bridging manner (placed without rigid anatomic reconstruction, p = 0.02) and length of follow-up (p = 0.01).

CONCLUSIONS

The SOP plating system can be used in the repair of appendicular longbone skeletal fractures, however, the authors propose that adjunct fixation, such as intramedullary pin, double plating, or external coaptation would likely improve results and should be considered imperative in cases in which anatomic reconstruction is either not desirable or achievable.

Comparison of Bite Force with Locking Plates versus Non-Locking Plates in the Treatment of Mandibular Fractures: A Meta-Analysis

Introduction  Mandibular fractures represent a high percentage of all facial fractures, and the bite force is a fundamental parameter to measure the actual mandibular function and, subsequently, the masticatory efficiency and quality of life. Objectives  The purpose of the present systematic review was to verify if there is any difference in the bite forces of patients with mandibular fractures fixed by locking or non-locking plates, testing the null hypothesis of no difference in this parameter. Data Synthesis  A systematic review of the literature was conducted using four databases (PubMed, Virtual Health Library, Web of Science and Science Direct) without restrictions as to publication date or language. We found 3,039 abstracts, and selected 4 articles for this review. Conclusion  The overall results show better performance in bite force for the locking plates when compared with the non-locking plates in the incisor region (mean deviation [MD]: 1.18; 95% confidence interval [95%CI]: 0.13-2.23), right molar region (MD: 4.71; 95%CI: 0.63-8.79) and left molar region (MD: 10.34; 95%CI: 4.55-16.13). Although the results of this study indicated a better bite force result with the locking plates, there is still no sufficient evidence to support this information safely.