scholarly journals Suitability of Metal Block Augmentation for Large Uncontained Bone Defect in Revision Total Knee Arthroplasty (TKA)

2019 ◽  
Vol 8 (3) ◽  
pp. 384 ◽  
Author(s):  
Kwan Kang ◽  
Trinh Tien ◽  
Myung Lee ◽  
Kwon-Yong Lee ◽  
Bongju Kim ◽  
...  

This study was performed to determine whether metal block augmentation is suitable for large uncontained bone defect via evaluations of differences in biomechanical characteristics among the configurations of metal block augmentations for medium or large uncontained bone defects in revision total knee arthroplasty (TKA). Three-dimensional finite element (FE) models of the proximal tibia with revision TKA were developed and analyzed considering the configurations of the metal block augmentations for medium and large uncontained bone defects. To identify differences in biomechanical characteristics according to the configurations of metal block augmentations, the stress transfer, strain distribution, and peak von Mises stresses (PVMSs) were assessed. Large and medium uncontained bone defects had similar ranges of strain below the critical bone-damage strain for the metal block augmentations, but the strain distribution characteristics differed in response to the metal block-augmentation configurations. PVMSs exceeding the yield strength of the bone cement for the single metal block-augmentation configurations were, on average, 1.4 times higher than those for double metal block-augmentation configurations for both medium and large uncontained bone defects. These findings suggest that metal block augmentation may be suitable for large uncontained bone defects (≤20 mm), compared with the results obtained for metal block augmentation used in medium uncontained bone defects (≤10 mm). If possible, double metal block augmentation is recommended for both medium and large uncontained bone defects rather than single metal block augmentation. It is also recommended that the metal block augmentation should be customized to meet the contact characteristics with the cortical bone, thereby ensuring better stress transfer and reducing the risk of the bone resorption due to stress shielding and bone-cement failure.

2020 ◽  
Author(s):  
Yang Li ◽  
Xinguang Wang ◽  
Hua Tian

Abstract Background: The reconstruction of massive bone defects is one of the main challenges in revision total knee arthroplasty (RTKA). Although several methods are available, each of them has its prominent shortcomings. The purpose of this study is to review the clinical outcomes of RTKA with massive proximal tibial bone defects using patient-customized three-dimensional (3D)-printed highly porous metaphyseal cones.Methods: We retrospectively reviewed seven RTKAs with Anderson Orthopaedic Research Institute (AORI) type III tibial defects using patient-customized 3D-printed highly porous metaphyseal cones, which have been performed at a single institution between 2016 and 2018. Results: The mean age at diagnosis of the patients was 68 years old (61-77). The mean length of follow-up was 25.3 months (19-36). At the latest follow-up, no aseptic loosening or prosthetic joint infection has been determined. The mean HSS increased from 49 (39-63) to 78 (70-83) (P<0.01); the mean WOMAC increased from 59 (46-73) to 26 (12-38) (P<0.01). All patients obtained the range of motion and mechanical alignment improvement postoperatively.Conclusion: The patient-customized 3D-printed metaphyseal cone could be a promising technique in addressing severe tibial defects in RTKA. Our study shows encouraging short-term clinical and radiological outcomes with no aseptic loosening, periprosthetic infection, or fracture. Nevertheless, further follow-up and the expansion of sample size are needed to demonstrate the advantage of this innovative technique fully.


2020 ◽  
Vol 28 (12) ◽  
pp. 3843-3848 ◽  
Author(s):  
Sebastian M. Klim ◽  
Florian Amerstorfer ◽  
Gerwin A. Bernhardt ◽  
Patrick Sadoghi ◽  
Georg Hauer ◽  
...  

Abstract Purpose Metaphyseal fixation in revision total knee arthroplasty (RTKA) is a very promising treatment option for extended bone defects. Currently published mid-term results remain limited. The purpose was to analyse the implant durability, the clinical and the radiological mid-term results in RTKA when using metaphyseal sleeves. Methods Clinical and radiological follow-up examinations were performed in 92 patients (93 knees) with RTKA using hybrid fixation technique (cementless sleeves and stem). Radiographic measurements regarding osseointegration at the bone–sleeve interface were performed and the range of motion (ROM), a subjective satisfaction score (SSS), the American Knee Society Score (KSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) as well as the SF-36 Health survey were examined. Bone defects were analysed using the Anderson Orthopaedic Research Institute (AORI) classification. Results No knee had to be revised due to aseptic loosening at the time of the follow-up (mean 6.3 years ± 2.3, minimum 2 years). Satisfactory radiographic osseointegration at the sleeve/bone interface was detected in 96.1% of cases. 17 knees (18.2%) had to be re-revised, 15 of them due to a recurrent infection and 2 due to aseptic reasons (mediolateral instability and a periprosthetic fracture). The median of the ROM (96°), SSS (8), KSS (87), WOMAC (9), SF-36 MCS (55) and SF-36 PCS (38) showed very satisfying results. Conclusion No case of aseptic loosening was found in this large series of RTKA with extended bone defects using metaphyseal sleeve fixation. In this large retrospective series, it has been shown that this technique is an excellent treatment option for extended bone defects in RTKA surgery. Level of evidence Retrospective cohort study, level III.


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