The biomechanical analysis of three plating fixation systems for periprosthetic femoral fracture near the tip of a total hip arthroplasty

James P Lever,Emil H Schemitsch,James P Waddell,Markku T Nousiainen,Rad Zdero

doi:10.1186/1749-799x-5-45

Abstract

BackgroundA variety of techniques are available for fixation of femoral shaft fractures following total hip arthroplasty. The optimal surgical repair method still remains a point of controversy in the literature. However, few studies have quantified the performance of such repair constructs. This study biomechanically examined 3 different screw-plate and cable-plate systems for fixation of periprosthetic femoral fractures near the tip of a total hip arthroplasty.MethodsTwelve pairs of human cadaveric femurs were utilized. Each left femur was prepared for the cemented insertion of the femoral component of a total hip implant. Femoral fractures were created in the femurs and subsequently repaired with Construct A (Zimmer Cable Ready System), Construct B (AO Cable-Plate System), or Construct C (Dall-Miles Cable Grip System). Right femora served as matched intact controls. Axial, torsional, and four-point bending tests were performed to obtain stiffness values.ResultsAll repair systems showed 3.08 to 5.33 times greater axial stiffness over intact control specimens. Four-point normalized bending (0.69 to 0.85) and normalized torsional (0.55 to 0.69) stiffnesses were lower than intact controls for most comparisons. Screw-plates provided either greater or equal stiffness compared to cable-plates in almost all cases. There were no statistical differences between plating systems A, B, or C when compared to each other (p > 0.05).ConclusionsScrew-plate systems provide more optimal mechanical stability than cable-plate systems for periprosthetic femur fractures near the tip of a total hip arthroplasty.

Highlights

A variety of techniques are available for fixation of femoral shaft fractures following total hip arthroplasty
Background uncommon, femoral fractures do occur in approximately 0.1% to 6% of all total hip arthroplasty cases [1,2,3,4]
Insertion of Total Hip Arthroplasties and Creation of Femoral Osteotomies Each left femur was prepared for the cemented insertion of the femoral component of a total hip implant

Summary

Introduction

A variety of techniques are available for fixation of femoral shaft fractures following total hip arthroplasty. This study biomechanically examined 3 different screw-plate and cable-plate systems for fixation of periprosthetic femoral fractures near the tip of a total hip arthroplasty. Femoral fractures do occur in approximately 0.1% to 6% of all total hip arthroplasty cases [1,2,3,4]. These are most often found in either osteopenic elderly women or in patients who have experienced loosening of the femoral component [1,5,6,7,8]. Middle-region fractures occur between the lesser trochanter and the prosthetic tip, are linked with prosthetic loosening, and often appear post-operatively. Distal fractures occur either in the post-operative period below well-fixed components or intra-operatively when an uncemented femoral stem impacts the intra-medullary wall anteriorly

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Results

Discussion

Conclusion