Abstract
Background
Determination of lower limb alignment is a prerequisite for successful orthopedic surgical treatment. Traditional methods include the electrocautery cord, alignment rod, or axis board which rely solely on C-arm fluoroscopy navigation and are radiation intensive.
Study objectives
To assess a new augmented reality technology in determining lower limb alignment.
Methods
A camera-augmented mobile C-arm (CamC) technology was used to create a panorama image consisting of hip, knee, and ankle X-rays. Twenty-five human cadaver legs were used for validation with random varus or valgus deformations. Five clinicians performed experiments that consisted in achieving acceptable mechanical axis deviation. The applicability of the CamC technology was assessed with direct comparison to ground-truth CT. A t test, Pearson’s correlation, and ANOVA were used to determine statistical significance.
Results
The value of Pearson’s correlation coefficient R was 0.979 which demonstrates a strong positive correlation between the CamC and ground-truth CT data. The analysis of variance produced a p value equal to 0.911 signifying that clinician expertise differences were not significant with regard to the type of system used to assess mechanical axis deviation.
Conclusion
All described measurements demonstrated valid measurement of lower limb alignment. With minimal effort, clinicians required only 3 X-ray image acquisitions using the augmented reality technology to achieve reliable mechanical axis deviation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Agarwala S, Sobti A, Agrawal P (2015) A report of nonunion at medial wedge high tibial osteotomy site and its management. J Nat Sci Biol Med 6(Suppl 1):160
Hankemeier S, Hufner T, Wang G, Kendoff D, Zheng G, Richter M, Gosling T, Nolte L, Krettek C (2005) Navigated intra-operative analysis of lower limb alignment. Archiv Orthop Trauma Surg 125(8):531–535
Krettek C, Miclau T, Gru O, Schandelmaier P, Tscherne H (1998) Intra-operative control of axes, rotation and length in femoral and tibial fractures technical note. Injury 29:29–39
Hawi N, Liodakis E, Suero EM, Meller R, Citak M, Krettek C (2014) A cadaver study comparing intra-operative methods to analyze lower limb alignment. Skelet Radiol 43(11):1577–1581
Navab N, Heining SM, Traub J (2010) Camera augmented mobile C-arm (CAMC): calibration, accuracy study, and clinical applications. IEEE Trans Med Imag 29(7):1412–1423
Wang L, Fallavollita P, Zou R, Chen X, Weidert S, Navab N (2012) Closed-form inverse kinematics for interventional C-arm X-ray imaging with six degrees of freedom: modeling and application. IEEE Trans Med Imag 31(5):1086–1099
Chen X, Wang L, Fallavollita P, Navab N (2012) Error analysis of the X-ray projection geometry of camera-augmented mobile C-arm. In: SPIE medical imaging, pp 83160P–83160P
Chen X, Wang L, Fallavollita P, Navab N (2013) Precise X-ray and video overlay for augmented reality fluoroscopy. Int J Comput Assist Radiol Surg 8(1):29–38
Diotte B, Fallavollita P, Wang L, Weidert S, Thaller PH, Euler E, Navab N (2012) Radiation-free drill guidance in interlocking of intramedullary nails. In: Medical image computing and computer-assisted intervention–MICCAI, pp 18–25
Pati S, Erat O, Wang L, Weidert S, Euler E, Navab N, Fallavollita P (2013) Accurate pose estimation using single marker single camera calibration system. In: SPIE medical imaging, pp 867126–867126
Wang L, Fallavollita P, Brand A, Erat O, Weidert S, Thaller PH, Euler E, Navab N (2012) Intra-op measurement of the mechanical axis deviation: an evaluation study on 19 human cadaver legs. In: Medical image computing and computer-assisted intervention–MICCAI, pp 609–616
Erat O, Pauly O, Weidert S, Thaller P, Euler E, Mutschler W, Navab N, Fallavollita P (2013) How a surgeon becomes superman by visualization of intelligently fused multi-modalities. In: SPIE medical imaging, pp 86710L–86710L
Pauly O, Diotte B, Habert S, Weidert S, Euler E, Fallavollita P, Navab N (2014) Relevance-based visualization to improve surgeon perception. In: Information processing in computer-assisted interventions, pp 178–185
Pauly O, Katouzian A, Eslami A, Fallavollita P, Navab N (2012) Supervised classification for customized intra-operative augmented reality visualization. In: Mixed and augmented reality (ISMAR), pp 311–312
Navab N, Bani-Kashemi A, Mitschke M (1999) Merging visible and invisible: two camera-augmented mobile C-arm (CAMC) applications. In: International workshop on augmented reality (IWAR), pp 134–141
Yaniv Z, Joskowicz L (2004) Long bone panoramas from fluoroscopic X-ray images. IEEE Trans Med Imag 23(1):26–35
Messmer P, Matthews F, Wullschleger C, Hügli R, Regazzoni P, Jacob AL (2006) Image fusion for intra-operative control of axis in long bone fracture treatment. Eur J Trauma 32(6):555–561
Paley D, Tetsworth K (1992) Mechanical axis deviation of the lower limbs: preoperative planning of uniapical angular deformities of the Tibia or Femur. Clin Orthop Relat Res 280:48–64
Sabharwal S, Zhao C (2008) Assessment of lower limb alignment: supine fluoroscopy compared with a standing full-length radiograph. J Bone Joint Surg 90(1):43–51
Liodakis E, Kenawey M, Doxastaki I, Krettek C, Haasper C, Hankemeier S (2011) Upright MRI measurement of mechanical axis and frontal plane alignment as a new technique: a comparative study with weight bearing full length radiographs. Skelet Radiol 40(7):885–889
Navab N, Blum T, Wang L, Okur A, Wendler T (2012) First deployments of augmented reality in operating rooms. Computer 7:48–55
Wieczorek M, Aichert A, Fallavollita P, Kutter O, Ahmadi A, Wang L, Navab N (2011) Interactive 3D visualization of a single-view X-Ray image. In: Fichtinger G, Martel A, Peters T (eds) Medical image computing and computer-assisted intervention–MICCAI 2011. Springer, Berlin, Heidelberg, pp 73–80
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interests.
Human and animal rights
This article does not contain any studies with human participants or animals performed by any of the authors. This article does not contain patient data.
Rights and permissions
About this article
Cite this article
Fallavollita, P., Brand, A., Wang, L. et al. An augmented reality C-arm for intraoperative assessment of the mechanical axis: a preclinical study. Int J CARS 11, 2111–2117 (2016). https://doi.org/10.1007/s11548-016-1426-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11548-016-1426-z