In:
Journal of Bone and Joint Surgery, Ovid Technologies (Wolters Kluwer Health), Vol. 100, No. 21 ( 2018-11-7), p. 1871-1878
Abstract:
The Radiographic Union Score for Tibial fractures (RUST) and the modified version of the system, mRUST, are popular standards for assessing fracture-healing progress with use of radiographs. To our knowledge, this is the first study to experimentally validate the ability of RUST and mRUST to accurately assess bone-healing progression with use of both micro-computed tomography (micro-CT) scanning and biomechanical testing. Methods: Adult male rats (n = 29) underwent osteotomy with a midshaft fracture gap repaired with use of a polyetheretherketone plate. Anteroposterior and lateral radiographs were made of the repaired femora prior to rat death at end points of 5, 6, 7, 8, 9, and 17 weeks, and 2 fellowship-trained orthopaedic trauma surgeons independently assigned RUST and mRUST scores to repaired femora. The repaired and intact contralateral femora were then dissected. Bones underwent dissection, micro-CT scanning, and biomechanical torsion testing at the end points. Results: RUST scores ranged from 5 to 12 and mRUST scores ranged from 5 to 16. Intraclass correlation coefficients (ICCs) were 0.89 (95% confidence interval [CI]: 0.78 to 0.94) for RUST and 0.86 (95% CI: 0.74 to 0.93) for mRUST, which fall within the “almost perfect agreement” category for ICCs. Spearman rank correlation coefficients (R S ) showed correlation of RUST (R S range, 0.456 to 0.818) and mRUST (R S range, 0.519 to 0.862) with micro-CT measurements of mineralized callus volume (BV), total callus volume (TV), and BV/TV ratio, but less so with bone mineral density (BMD). Additionally, RUST (R S range, 0.524 to 0.863) and mRUST (R S range, 0.434 to 0.850) were correlated with some biomechanical properties. A RUST score of 10 or an mRUST score of 15 may be considered the threshold above which a plated bone is “healed” because, at these scores, 120% or 140% of failure torque, respectively, was achieved by the repaired femora as compared with the intact contralateral femora. Conclusions: RUST and mRUST both show strong statistical correlations with micro-CT and biomechanical parameters. Clinical Relevance: RUST and mRUST scoring systems provide clinicians with validated, reliable, and available tools to assess the progress of fracture-healing.
Type of Medium:
Online Resource
ISSN:
0021-9355
,
1535-1386
DOI:
10.2106/JBJS.18.00035
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2018
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