Laser-Induced Microgrooves Improve the Mechanical Responses of Cemented Implant Systems

Morshed Khandaker,Abdellah Ait Moussa,Fereshteh Safavinia,Onur Can Kalay,Desmond Nuyebga Sama,Fatih Karpat,Susmita Hazra,Amgad Haleem,Erik Clary

doi:10.3390/mi11050466

Abstract

The impact of a laser-induced microgroove (LIM) architecture on mechanical responses of two cemented implant systems was evaluated. One system consisted of two aluminum alloy rods bonded end-to-end by polymethylmethacrylate cement. The second system consisted of a custom-made, aluminum tibial tray (TT) cemented in an artificial canine tibia. Control specimens for each system were polished smooth at the cement interface. For LIM samples in the rod system, microgrooves were engraved (100 µm depth, 200 µm width, 500 µm spacing) on the apposing surface of one of the two rods. For TT system testing, LIM engraving (100 µm spacing) was confined to the underside and keel of the tray. Morphological analysis of processed implant surfaces revealed success in laser microgrooving procedures. For cemented rods tested under static tension, load to failure was greater for LIM samples (279.0 ± 14.9 N vs. 126.5 ± 4.5 N). Neither non-grooved nor grooved TT samples failed under cyclic compression testing (100,000 cycles at 1 Hz). Compared with control specimens, LIM TT constructs exhibited higher load to failure under static compression and higher strain at the bone interface under cyclic compression. Laser-induced microgrooving has the potential to improve the performance of cemented orthopedic implants.

Highlights

Total joint replacement (TJR) is a surgical procedure in which the surfaces of a diseased joint are excised and replaced with two metal prostheses and a polyethylene articulation between them
Our preliminary studies showed that microgrooving cementless titanium (Ti) implants significantly improve biocompatibility, mechanical stability, and osseointegration of the device [11,12]
We report our evaluation of a novel laser-induced microgroove (LIM) architecture on the mechanical performance of two cemented aluminum alloy devices—one a bonded rod system and the other a total knee replacement (TKR) tibial tray—working on the hypothesis that LIM would enhance cement bonding and improve mechanical performance

Summary

Introduction

Total joint replacement (TJR) is a surgical procedure in which the surfaces of a diseased joint are excised and replaced with two metal prostheses and a polyethylene articulation between them. To secure the prostheses in place, TJR systems may employ either bone cement (polymethylmethacrylate (PMMA)) or a press-fit strategy. The cemented approach is generally reserved for osteoporotic bone whereas cementless fixation requires healthy bone for immediate (via press-fit) and longer-term (via bony ingrowth) stability [1,2]. An ideal implant for TJR surgery should deliver lifelong stability within the adjacent tissue [3]. In the U.S alone, approximately 40,000 hip arthroplasty surgeries have to be revised each year, and the rate is expected to increase by 137% (and by 601% for total knee revisions) over the 25 years as the population ages [5]. Improving TJR implant durability, is of the utmost clinical importance [6]

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Results

Conclusion