Objective: This study aimed to determine the reliability levels of the radiographic union scale for tibial fractures (RUST) and the modifiedversion of the system, mRUST, for femoral shaft fractures in pediatric and adult patients and to evaluate the value of the scores for totaland each cortex in the decision making on fracture union.Methods: A total of 15 orthopedic surgeons scored the radiographs of 24 pediatric and 24 adult patients with femoral shaft fractures thatwere obtained at 0, 4, 8, 12, and 16 postoperative weeks treated with elastic stable intramedullary nail in pediatric patients and locked intramedullary nail in adult patients using the RUST and mRUST scores. Intra-class correlation coefficient (ICC) was used in the evaluationof reliability of the RUST and mRUST scores. The Fleiss kappa (k) coefficient was used in the agreement between evaluators regardingunion decision (united or non-united). The thresholds for RUST and mRUST for radiographic union decision were determined. Receiveroperating curves were created to evaluate the contribution of total and individual cortical scores in the decision of united or non-united.Results: Intra- and inter-rater reliabilities of mRUST (ICC: 0.92 and 0.86, respectively) were slightly higher than those of RUST (ICC: 0.81and 0.77, respectively) with perfect intra- and inter-rater reliabilities for RUST (ICC: 0.92 and 0.90, respectively) and mRUST (ICC: 0.88 and0.83, respectively) in pediatric patients and substantial intra- and inter-rater reliabilities in adult patients (ICC: 0.80 and 0.76, respectively, formRUST, and 0.76 and 0.71, respectively, for RUST). At each time point, the mean mRUST and RUST scores were higher for pediatric fractures(p
___
1. Morshed S. Current options for determining fracture union. Adv Med 2014; 2014: 708574.
2. Corrales LA, Morshed S, Bhandari M, Miclau T 3rd. Variability in the assessment of fracture-healing in orthopaedic trauma studies. J Bone Joint Surg Am 2008; 90: 1862-8.
3. Bhandari M, Guyatt GH, Swiontkowski MF, Tornetta P 3rd, Sprague S, Schemitsch EH. A lack of consensus in the assessment of fracture healing among orthopaedic surgeons. J Orthop Trauma. 2002; 16: 562-6.
4. Litrenta J, Tornetta P 3rd, Mehta S, et al. Determination of radiographic healing: An assessment of consistency using RUST and modified RUST in Metadiaphyseal fractures. J Orthop Trauma 2015; 29: 516-20.
5. Dijkman BG, Sprague S, Schemitsch EH, Bhandari M. When is a fracture healed? Radiographic and clinical criteria revisited. J Orthop Trauma 2010; 24(Suppl 1): S76-80.
6. Whelan DB, Bhandari M, Stephen D, et al. Development of the radiographic union score for tibial fractures for the assessment of tibial fracture healing after intramedullary fixation. J Trauma 2010; 68: 629-32.
7. Kooistra BW, Dijkman BG, Busse JW, Sprague S, Schemitsch EH, Bhandari M. The radiographic union scale in tibial fractures: reliability and validity. J Orthop Trauma 2010; 24: S81-S6.
8. Leow JM, Clement ND, Tawonsawatruk T, Simpson CJ, Simpson AHRW. The radiographic union scale in tibial (RUST) fractures: Reliability of the outcome measure at an independent centre. Bone Joint Res 2016; 5: 116-21.
9. DiSilvio F Jr, Foyil S, Schiffman B, Bernstein M, Summers H, Lack WD. Long bone union accurately predicted by cortical bridging within 4 months. J Bone Joint Surg Am Open Access 2018; 3: e0012.
10. Islam O, Soboleski D, Symons S, Davidson LK, Ashworth MA, Babyn P. Development and duration of radiographic signs of bone healing in children. Am J Roentgenol 2000; 175: 75-8.
11. Lindaman LM. Bone healing in children. Clin Podiatr Med Surg 2001; 18: 97-108.
12. Schell H, Duda GN, Peters A, Tsitsilonis S, Johnson KA, Schmidt-Bleek K. The haematoma and its role in bone healing. J Exp Orthop 2017; 4: 5.
13. Perlepe V, Cerato A, Putineanu D, et al. Value of a radiographic score for the assessment of healing of nailed femoral and tibial shaft fractures: A retrospective preliminary study. Eur J Radiol 2018; 98: 36-40.
14. Debuka E, Kushwaha NS, Kumar D, Singh A, Sharma V. Rust score-An adequate rehabilitation guide for diaphyseal femur fractures managed by TENS. J Clin Orthop Trauma 2019; 10: 922-7.
15. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977; 33: 159-74.
16. Tape T. The area under an ROC curve: interpreting diagnostic tests. Available at: http://gim.unmc.edu/dxtests/roc3.htm. Accessed 26 May 2020.
17. Sganga ML, Summers NJ, Barrett B, et al. Radiographic union scoring scale for determining consolidation rates in the calcaneus. J Foot Ankle Surg 2018; 57: 2-6.
18. Franzone JM, Finkelstein MS, Rogers KJ, Kruse RW. Evaluation of fracture and osteotomy union in the setting of osteogenesis imperfecta: Reliability of the modified radiographic union score for tibial fractures (RUST). J Pediatr Orthop 2020; 40: 48-52.
19. Richards BS, Wilkes D, Dempsey M, Nurenberg P. A radiographic scoring system to assess healing in congenital pseudoarthrosis of the tibia. J Pediatr Orthop B 2015; 24(2): 118-22.
20. Patel SP, Anthony SG, Zurakowski D, et al. Radiographic scoring system to evaluate union of distal radius fractures. J Hand Surg 2014; 39: 1471-9.
21. Eliezer EN, Haonga BT, Morshed S, Shearer DW. Predictors of reoperation for adult femoral shaft fractures managed operatively in a sub-Saharan country. J Bone Joint Surg Am 2017; 99: 388-95.
22. Cooke ME, Hussein AI, Lybrand KE, et al. Correlation between RUST assessments of fracture healing to structural and biomechanical properties. J Orthop Res 2018; 36: 945-53.
23. Fisher JS, Kazam JJ, Fufa D, Bartolotta RJ. Radiologic evaluation of fracture healing. Skeletal Radiol 2019; 48: 349-61.
24. Grigoryan M, Lynch JA, Fierlinger AL, et al. Quantitative and qualitative assessment of closed fracture healing using computed tomography and conventional radiography. Acad Radiol 2003; 10: 1267-3.
25. Firoozabadi R, Morshed S, Engelke K, et al. Qualitative and quantitative assessment of bone fragility and fracture healing using conventional radiography and advanced imaging technologies-focus on wrist fracture. J Orthop Trauma 2008; 22(8 Suppl): S83-90.
26. Niikura T, Lee SY, Sakai Y, Nishida K, Kuroda R, Kurosaka M. Comparison of radiographic appearance and bone scintigraphy in fracture nonunions. Orthopedics 2014; 37(1): e44-50.