Automatic Joint Alignment Measurements in Pre- and Post-operative Long Leg Standing Radiographs

Summary

Objectives: For diagnosis or treatment assessment of knee joint osteoarthritis it is required to measure bone morphometry from radiographic images. We propose a method for automatic measurement of joint alignment from pre-operative as well as post-operative radiographs.

Methods: In a two step approach we first detect and segment any implants or other artificial objects within the image. We exploit physical characteristics and avoid prior shape information to cope with the vast amount of implant types. Subsequently, we exploit the implant delineations to adapt the initialization and adaptation phase of a dedicated bone segmentation scheme using deformable template models. Implant and bone contours are fused to derive the final joint segmentation and thus the alignment measurements.

Results: We evaluated our method on clinical long leg radiographs and compared both the initialization rate, corresponding to the number of images successfully processed by the proposed algorithm, and the accuracy of the alignment measurement. Ground truth has been generated by an experienced orthopedic surgeon. For comparison a second reader reevaluated the measurements. Experiments on two sets of 70 and 120 digital radiographs show that 92% of the joints could be processed automatically and the derived measurements of the automatic method are comparable to a human reader for pre-operative as well as post-operative images with a typical error of 0.7° and correlations of r = 0.82 to r = 0.99 with the ground truth.

Conclusions: The proposed method allows deriving objective measures of joint alignment from clinical radiographs. Its accuracy and precision are on par with a human reader for all evaluated measurements.

Keywords

Radiography - bone - lower extremity - replacement arthroplasty - orthopedics

• References

• 1 Hall MJ, DeFrances CJ, Williams SN, Golosinskiy A, Schwartzman A. National Hospital Discharge Survey: 2007 Summary. National Health Statistics Reports. 2010: 29
• 2 Wade RH, Kevu J, Doyle J. Pre-operative planning in orthopaedics: a study of surgeons’ opinions. Injury 1998; 29 (10) 785-786.
• 3 Boewer M, Arndt H, Ostermann PW, Petersein J, Mutze S. Length and angle measurements of the lower extremity in digital composite overview images. Eur Radiol 2005; 15 (01) 158-164.
• 4 Paley D, Herzenberg JE. Principles of Deformity Correction. 1st ed. Springer; 2002
• 5 Pafilas D, Nayagam S. The pelvic support osteotomy: indications and preoperative planning. Strategies in Trauma and Limb Reconstruction 2008; 3 (02) 83-92.
• 6 Krackow KA. Approaches to planning lower extremity alignment for total knee arthroplasty and osteotomy about the knee. Adv Orthop Surg 1983; 7: 69-88.
• 7 Laskin RS. Alignment of total knee components. Orthopedics 1984; 7: 62-72.
• 8 Hankemeier S, Gosling T, Richter M, Hufner T, Hochhausen C, Krettek C. Computer-assisted analysis of lower limb geometry: higher intraobserver reliability compared to conventional method. Comput Aided Surg 2006; 11: 81-86.
• 9 Ilahi OA, Kadakia NR, Huo MH. Inter- and intraobserver variability of radiographic measurements of knee alignment. Am J Knee Surg 2001; 14: 238-242.
• 10 Ehrhardt J, Handels H, Plötz W, Pöppl SJ. Atlas-based recognition of anatomical structures and landmarks and the automatic computation of orthopedic parameters. Methods Inf Med 2004; 43 (04) 391-397.
• 11 Gooßen A, Hermann E, Weber GM, Gernoth T, Pralow T, Grigat RR. Model-based segmentation of pediatric and adult joints for orthopedic measurements in digital radiographs of the lower limbs. Computer Science - Research and Development 2011; 26: 107-116.
• 12 Dong X, Zheng G. Automatic extraction of femur contours from calibrated x&hypen;ray images:A Bayesian inference approach. In: 5th IEEE International Symposium on Biomedical Imaging. Berlin/Heidelberg: Springer; 2008: 57-60.
• 13 Kotcheff ACW, Redhead A, Taylor CJ, Hukins DWL. Shape Model Analysis of THR Radiographs. In: Proc ICPR ’96. vol. 7472. IEEE Computer Society 1996; 391-395.
• 14 Cootes TF, Hill A, Tailor CJ, Haslam J. The Use of Active Shape Models For Locating Structures in Medical Images. Image Vis Comput 1994; 12 (06) 355-366.
• 15 Gooßen A, Hermann E, Gernoth T, Pralow T, Grigat RR. Model-Based Lower Limb Segmentation using Weighted Multiple Candidates. In. Meinzer HP, Deserno TM, Handels H, Tolxdorff T. editors. Proc BVM 2010. Springer; 2010: 376-380.
• 16 Ranawat CS. History of total knee replacement. Journal of the Southern Orthopaedic Association 2002; 11 (04) 218-226.
• 17 Mont MA, Jr REB, Laskin RS, Stiehl JB, Ritter MA, Stuchin SA. etal The spectrum of prosthesis design for primary total knee arthroplasty. Instructional Course Lectures 2003; 52: 397-407.
• 18 Schreiber J, Schubert R, Kuhn V. Femur Detection in Radiographs Using Template-Based Registration. In. Handels H, Ehrhardt J, Horsch A, Meinzer HP, Tolxdorff T. editors. Proc BVM 2006. Springer: 2006: 111-115.
• 19 Chan TF, Vese LA. Active Contours without Edges. IEEE Trans Image Process 2001; 10 (02) 266-277.
• 20 Otsu N. A threshold selection method from gray- level histograms. IEEE Trans Syst Man Cybern 1979; 9 (01) 62-66.
• 21 Prakash U, Wigderowitz CA, McGurty DW, Rowley I D. Computerised measurement of tibiofemoral alignment. J Bone Joint Surg Br 2001; 83-B: 819-824.
• 22 Ruppertshofen H, Lorenz C, Schmidt S, Beyerlein P, Salah Z, Rose G. etal Discriminative Generalized Hough transform for localization of joints in the lower extremities. Computer Science - Research and Development 2011; 26: 97-105.
• 23 Lampe F, Sufi-Siavach A, Bohlen KE, Hille E, Dries SP. One year after navigated total knee replacement, no clinically relevant difference found between fixed bearing and mobile bearing knee replacement in a double-blind randomized controlled trial. Open Orthop J 2011; 5: 201-208.
• 24 Siu D, Cooke DV, Broekhoven LD, Lam B Miuand Fisher, Saunders G, Challis TW. A Standardized Technique for Lower Limb Radiography Practice, Applications, and Error Analysis. Invest Radiol 1991; 26 (01) 71-76.
• 25 Choong PF, Dowsey MM, Stoney JD. Does accurate anatomical alignment result in better function and quality of life? Comparing conventional and computer-assisted total knee arthroplasty. J Arthroplasty 2009; 24 (04) 560-599.
• 26 Rauh MA, Boyle J, Mihalko WM, Phillips MJ, Bayers-Thering M, Krackow KA. Reliability of measuring long-standing lower extremity radiographs. Orthopedics 2007; 30 (04) 299-303.
• 27 Sailer J, Scharitzer M, Peloschek P, Giurea A, Imhof H, Grampp S. Quantification of axial alignment of the lower extremity on conventional and digital total leg radiographs. Eur Radiol 2005; 15 (01) 170-173.