Cemented Versus Hybrid Technique of Fixation of the Stemmed Revision Total Knee Arthroplasty: A Literature Review

A Literature Review

Charles Ayekoloye, MD, FRCS; Mehran Radi, MD; David Backstein, MD, MED, FRCSC; Moayad Abu Qa'oud, MD

Disclosures

J Am Acad Orthop Surg. 2022;30(9):e703-e713. 

In This Article

Porous Metal Sleeves and Cones

Recent introduction and use of porous metal cones and metaphyseal sleeves as void fillers have helped to provide a means of more consistently achieving successful and lasting reconstruction of large metaphyseal bone defects. These are used in combination with stems that are fixed by either technique. Tantalum is a frequently used metal because it has excellent material and biomechanical properties that make it an ideal material for reconstructing bone defects. It is highly biocompatible with extremely low immunogenicity and has high corrosion resistance. Its high coefficient of friction results in immediate primary press-fit stability in metaphyseal bone. It has identical elastic modulus to bone, which avoids stress shielding of adjacent proximal bone.[31]

The high (80%) porosity of tantalum encourages rapid and extensive bone ingrowth of 40% to 50% by 4 weeks and 80% or more by 18 weeks.[31] This results in the formation of a strong, stress-resistant biologic interface and a stable and lasting metaphyseal reconstruction.

A recent experimental study evaluating the use of cones with stems fixed by either hybrid or fully cemented modes in moderate metaphyseal defects showed that the cones provided stability to the whole construct with both modes of stem fixation performing equally well.[36]

Clinical studies have shown excellent results at a short-term to medium-term follow-up with low aseptic loosening rates when porous metal cones are used with stems in patients with high-grade (AORI 2B/3) defects.

Meneghini et al undertook 15 knee revisions in 15 patients using 15 cones with both types of stem fixation. At mean 34 months of follow-up, the mean KSS improved from 52 to 84 points. All cones had osteointegration with no aseptic loosening.[37] Lachiewicz et al reported 24 patients with 24 tibial and 9 femoral cones combined with both modes of stem fixation. Thirteen patients (48%) underwent reimplantation for infection. The mean KSS improved from 40 to 79 points with functional score improving from 19 to 47 points. One septic loosening was reported at a mean 39-month follow-up with no case of aseptic loosening.[38] Backstein et al examined 29 patients treated with 33 cones (17 tibia and 18 femur) combined with hybrid stem fixation. At a mean 33-month follow-up, the mean KSS improved from 42 to 88, function improved from 32 to 65, and mean ROM improved from 88 to 112 degrees, with no aseptic loosening.[39]

These results are better than those obtained with use of bulk allograft. Backstein et al[40] at a mean follow-up of 64 months reported 21.3% allograft failure rates due to nonunion, loosening, infection, periprosthetic fracture, and instability when bulk allograft was used to reconstruct major bone defects in rTKA. A systematic review by Beckmann et al[6] showed significantly higher failure rates with bulk allograft compared with TM cones.

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