3D ultrasound reconstruction of sonographic callus

Abstract

Aims The aim of this study was to establish a reliable method for producing 3D reconstruction of sonographic callus. Methods A cohort of ten closed tibial shaft fractures managed with intramedullary nailing underwent ultrasound scanning at two, six, and 12 weeks post-surgery. Ultrasound capture was performed using infrared tracking technology to map each image to a 3D lattice. Using echo intensity, semi-automated mapping was performed to produce an anatomical 3D representation of the fracture site. Two reviewers independently performed 3D reconstructions and kappa coefficient was used to determine agreement. A further validation study was undertaken with ten reviewers to estimate the clinical application of this imaging technique using the intraclass correlation coefficient (ICC). Results Nine of the ten patients achieved union at six months. At six weeks, seven patients had bridging callus of ≥ one cortex on the 3D reconstruction and when present all achieved union. Compared to six-week radiographs, no bridging callus was present in any patient. Of the three patients lacking sonographic bridging callus, one went onto a nonunion (77.8% sensitive and 100% specific to predict union). At 12 weeks, nine patients had bridging callus at ≥ one cortex on 3D reconstruction (100%-sensitive and 100%-specific to predict union). Presence of sonographic bridging callus on 3D reconstruction demonstrated excellent reviewer agreement on ICC at 0.87 (95% confidence interval 0.74 to 0.96). Conclusion 3D fracture reconstruction can be created using multiple ultrasound images in order to evaluate the presence of bridging callus. This imaging modality has the potential to enhance the usability and accuracy of identification of early fracture healing. Cite this article: Bone Joint Res 2021;10(12):759–766.

Pragmatic use of ultrasound in plaster room

“…3 According to Nicholson et al, ultrasound may be a valuable device for monitoring fracture healing particularly in early stages. 2,4 Ultrasound has been recommended as a suitable guidance tool for routinely wrist fracture reduction. 5 F I G U R E 8 X-rays before reduction of distal radial Salter Harris type 1 epiphyseal fracture.…”

“…According to Nicholson et al, ultrasound may be a valuable device for monitoring fracture healing particularly in early stages 2,4 …”

Ultrasound assessment of humeral shaft nonunion risk: a feasibility and proof of concept study

“…Assessment of microvascular blood flow using Doppler ultrasound may have enhanced our ability to assess callus vascularity, although there is controversy regarding the importance of trends in Doppler parameters (such as the RI and the spectral waveform) in the context of nonunion [ 11 , 16 ]. It is recognised that the use and interpretation of ultrasound are operator-dependent [ 29 ], and while three-dimensional ultrasound reconstruction holds the promise of further improving reliability [ 30 ], the requirement for detailed image rendering currently obviates the benefits in terms of immediacy and usability in the outpatient setting.…”