Liaw's Ellipse Anteversion Method for Distinguishing Acetabular Component Retroversion from Anteversion on Plain Radiographs

Abstract

Improper acetabulum component position is a significant risk factor for postoperative dislocation after total hip arthroplasty. Several radiographic two-dimensional methods exist for measuring acetabulum component anteversion, but they cannot distinguish between anteversion and retroversion. “Liaw's version,” initially proposed as a simple mathematical standardized two-dimensional method, was modified to the computerized ellipse method, proving superior accuracy to traditional two-dimensional methods. In this article, we demonstrated its application in detecting and measuring retroverted acetabulum component. We obtained anteroposterior pelvis radiographs from a patient undergoing total hip arthroplasty on the day of surgery and 2 weeks postoperatively. The computerized ellipse method was used to measure the acetabulum component orientation. Upon comparison, the difference between θ assigned to be retroverted (9.52–8.56 = 0.96) is much smaller than the difference between θ assigned to be anteverted (23.81–18.86 = 4.95), leading us to determine retroversion. This was further confirmed by computed tomography at the 6-week follow-up. We propose that using the computerized ellipse method to measure Liaw's version can be a valuable tool in identifying acetabulum component retroversion on anteroposterior radiographs during routine postoperative follow-up and retrospective assessments of total hip arthroplasty patients.

Keywords

Acetabulum / Ellipse Method / Liaw's Version / Radiographs / Retroversion / Total Hip Arthroplasty

References

[1] Karachalios T, Komnos G, Koutalos A. Total hip arthroplasty: survival and modes of failure. EFORT Open Rev. 2018;3(5):232–239.

[2] Bozic KJ, Kurtz SM, Lau E, Ong K, Vail TP, Berry DJ. The epidemiology of revision total hip arthroplasty in the United States. J Bone Joint Surg Am. 2009;91(1):128–133.

[3] Lewinnek GE, Lewis JL, Tarr R, Compere CL, Zimmerman JR. Dislocations after total hip-replacement arthroplasties. J Bone Joint Surg Am. 1978;60(2):217–220.

[4] Jolles BM, Zangger P, Leyvraz PF. Factors predisposing to dislocation after primary total hip arthroplasty: a multivariate analysis. J Arthroplasty. 2002;17(3):282–288.

[5] Soong M, Rubash HE, Macaulay W. Dislocation after total hip arthroplasty. J Am Acad Orthop Surg. 2004;12(5):314–321.

[6] Biedermann R, Tonin A, Krismer M, Rachbauer F, Eibl G, Stockl B. Reducing the risk of dislocation after total hip arthroplasty: the effect of orientation of the acetabular component. J Bone Joint Surg Br. 2005;87(6):762–769.

[7] Parvizi J, Kim KI, Goldberg G, Mallo G, Hozack WJ. Recurrent instability after total hip arthroplasty: beware of subtle component malpositioning. Clin Orthop Relat Res. 2006;447:60–65.

[8] Kennedy JG, Rogers WB, Soffe KE, Sullivan RJ, Griffen DG, Sheehan LJ. Effect of acetabular component orientation on recurrent dislocation, pelvic osteolysis, polyethylene wear, and component migration. J Arthroplasty. 1998;13(5):530–534.

[9] D'Lima DD, Urquhart AG, Buehler KO, Walker RH, Colwell CW. The effect of the orientation of the acetabular and femoral components on the range of motion of the hip at different head-neck ratios. J Bone Joint Surg Am. 2000;82(3):315–321.

[10] Patil S, Bergula A, Chen PC, Colwell CW, D'Lima DD. Polyethylene wear and acetabular component orientation. J Bone Joint Surg Am. 2003;85-A Suppl 4:56–63.

[11] Widmer KH, Zurfluh B. Compliant positioning of total hip components for optimal range of motion. J Orthop Res. 2004;22(4):815–821.

[12] Murray DW. The definition and measurement of acetabular orientation. J Bone Joint Surg Br. 1993;75(2):228–232.

[13] Woo RY, Morrey BF. Dislocations after total hip arthroplasty. J Bone Joint Surg Am. 1982;64(9):1295–1306.

[14] Ackland MK, Bourne WB, Uhthoff HK. Anteversion of the acetabular cup. Measurement of angle after total hip replacement. J Bone Joint Surg Br. 1986;68(3):409–413.

[15] Hassan DM, Johnston GH, Dust WN, Watson LG, Cassidy D. Radiographic calculation of anteversion in acetabular prostheses. J Arthroplasty. 1995;10(3):369–372.

[16] Pradhan R. Planar anteversion of the acetabular cup as determined from plain anteroposterior radiographs. J Bone Joint Surg Br. 1999;81(3):431–435.

[17] Widmer KH. A simplified method to determine acetabular cup anteversion from plain radiographs. J Arthroplasty. 2004;19(3):387–390.

[18] Liaw C-K, Yang R-S, Hou S-M, Wu T-Y, Fuh C-S. A simple mathematical standardized measurement of acetabulum Anteversion after Total hip arthroplasty. Comput Math Methods Med. 2008;9(2):105–119.

[19] Liaw CK, Wu TY, Hou SM, Yang RS, Shih KS, Fuh CS. Computerized ellipse method for measuring acetabular version after total hip replacement – a precision study using synthetic and real radiographs. Comput Aided Surg. 2013;18(5–6):195–200.

[20] Yeh KL, Wu TY, Ma HH, Hou SM, Liaw CK. Ellipse method for measuring Liaw's anteversion of the acetabular component after total hip arthroplasty. BMC Musculoskelet Disord. 2020;21(1):667.

[21] Kalteis T, Handel M, Herold T, Perlick L, Paetzel C, Grifka J. Position of the acetabular cup – accuracy of radiographic calculation compared to CT-based measurement. Eur J Radiol. 2006;58(2):294–300.

[22] Ghelman B, Kepler CK, Lyman S, Della Valle AG. CT outperforms radiography for determination of acetabular cup version after THA. Clin Orthop Relat Res. 2009;467(9):2362–2370.

[23] McArthur B, Cross M, Geatrakas C, Mayman D, Ghelman B. Measuring acetabular component version after THA: CT or plain radiograph? Clin Orthop Relat Res. 2012;470(10):2810–2818.

RIGHTS & PERMISSIONS

2023 2023 The Authors. Orthopaedic Surgery published by Tianjin Hospital and John Wiley & Sons Australia, Ltd.