SLR - October 2013 - Joseph Genualdi

A Biomechanical Comparison of One-Third Tubular Plates Versus Periarticular Plates for Fixation of Osteoporotic Distal Fibula Fractures

Reference: Adrian T. Davis, MD, Heidi Israel, PhD, Lisa K. Cannada, MD, and J. Gary Bledsoe, PhD  J Orthop Trauma 2013;27:e201–e207

Scientific Literature Review

Reviewed by: Joseph Genualdi, DPM
Residency Program:
University Hospital- Newark, NJ

Podiatric Relevance: Ankle fractures are a relatively common traumatic injury sustained in the general population. The demographic with the highest incidence of ankle fractures has been found to be in older women, who also have an increased risk of osteoporosis and consequently decreased fracture healing potential. The authors in this article reference population-based studies, which predict a continued increase in the incidence of ankle fractures in older patients over the next few decades. As a result, foot and ankle surgeons will be increasingly challenged to provide proper fixation for unstable malleolar fractures in the aging population. This article was designed to compare the biomechanical properties of different plating techniques which have been used in the treatment of distal fibular fractures.

Methods: Twenty-four cadaveric legs meeting criteria of osteoporosis on DEXA scan had soft tissue dissected so that only the bone and ligaments remained. A custom jig was used to make an identical oblique distal fibular osteotomy in all specimens. Standard technique was used to anatomically reduce fractures with placement of an interfragmentary lag screw. Specimens were divided evenly among four testing groups: nonlocking seven-hole one-third tubular plate, non-locking six-hole periarticular distal lateral fibular plate, locking seven-hole one-third tubular plate and locking four-hole periarticular distal lateral fibular plate. After plating, collateral ligaments were transected to mimic SER IV injury. Specimens were tested on a MTS 858 MiniBionix machine (Eden Prairie, MN) for axial stiffness, rotational stiffness and torque to failure. Failure was defined as hardware breakage, screw pullout, and/or fracture of bone.

Results: Periarticular plates were found to have greater rotational stiffness and torque to failure than one-third tubular plates, with a statistically significant difference for rotational stiffness only. No statistically significant difference in axial stiffness was found between the plate constructs. When comparing locking vs nonlocking, nonlocking one-third tubular plates had a statistically significant greater torque to failure then locking one-third tubular plates; nonlocking periarticular plates had greater torque to failure then locking periarticular plates but did not reach statistical significance.

Conclusions: There have been various techniques described for the fixation of lateral malleolar fractures. The authors concluded that one-third tubular plates perform similarly to periarticular plates and therefore remain a viable option for treatment of osteoporotic fibular fractures. Locking plates were surprisingly found to be inferior to non-locking plates in torsional stability, which is an important finding considering the increased cost of locking plate technology. Future clinical trials are needed to further assess the patient outcomes of different plate technology in osteoporotic distal fibular fractures.

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