Distal Femur Morphology in a Brazilian Population: Challenging the Universal Use of 3° of External Rotation

Abstract

Objective To evaluate the external rotation angle between the transepicondylar axis (TEA) and the posterior condylar axis (PCA) in a Brazilian population to determine whether the universal use of 3° of external rotation of the femoral component is appropriate in these patients undergoing total knee arthroplasty (TKA).

Methods We measured the angle of external rotation in 167 magnetic resonance imaging (MRI) scans using 4 different methods for the PCA according to the posterior landmarks: measurement A – chondral prominences; measurement B – bony prominences; measurement C – lateral bony prominence and medial chondral prominence; and measurement D – lateral chondral prominence and medial bony prominence. We statistically compared these measurements with the traditional 3° of external rotation used in TKA.

Results The mean angles of external rotation in measurements A, B, C, and D were of 5.44° ± 2.39°, 4.94° ± 2.10°, 8.56° ± 2°, and 2.33° ± 2° respectively. All measurement methods resulted in significant differences regarding the universal value of 3° (p > 0.0001). All intergroup comparisons showed statistical differences among the measurement methods (p > 0.0001), except for the comparison between measurements A and B (p = 0.1614).

Conclusion Using a chondral or bony reference point for the PCA, the TEA in the Brazilian population studied presented approximately 5° of external rotation. The traditional rotation of the femoral component of 3° regarding the PCA may be insufficient in the Brazilian population, especially in valgus knees. Therefore, we emphasize the significance of an individualized approach to achieve the ideal rotational alignment of TKA components.

Keywords

arthroplasty, replacement, knee - knee joint - magnetic resonance imaging - rotation

• Referências

• 1 Ferreira MC, Oliveira JCP, Zidan FF, Franciozi CEDS, Luzo MVM, Abdalla RJ. Total knee and hip arthroplasty: the reality of assistance in Brazilian public health care. Rev Bras Ortop 2018; 53 (04) 432-440
• 2 Lee JK, Lee S, Chun SH, Kim KT, Lee MC. Rotational alignment of femoral component with different methods in total knee arthroplasty: a randomized, controlled trial. BMC Musculoskelet Disord 2017; 18 (01) 217
• 3 Barrack RL, Schrader T, Bertot AJ, Wolfe MW, Myers L. Component rotation and anterior knee pain after total knee arthroplasty. Clin Orthop Relat Res 2001; (392) 46-55
• 4 Carvalho Júnior LH, Gonçalves MBJ, Soares LFM, Silva RC. Alinhamento rotacional do componente femoral na artroplastia total do joelho. Rev Bras Ortop 2007; 42 (08) 244-247
• 5 Victor J. Rotational alignment of the distal femur: a literature review. Orthop Traumatol Surg Res 2009; 95 (05) 365-372
• 6 Cho Y, Lee MC. Rotational alignment in total knee arthroplasty. Asia Pac J Sports Med Arthrosc Rehabil Technol 2014; 1 (04) 113-118
• 7 Berger RA, Rubash HE, Seel MJ, Thompson WH, Crossett LS. Determining the rotational alignment of the femoral component in total knee arthroplasty using the epicondylar axis. Clin Orthop Relat Res 1993; (286) 40-47
• 8 Murgier J, Chantalat É, Li K. et al. Distal femoral torsion: Differences between caucasians and asians. A multicentre computed tomography study of 515 distal femurs. Orthop Traumatol Surg Res 2018; 104 (07) 997-1001
• 9 Pun TB, Krishnamoorthy VP, Korula RJ, Poonnoose PM. Distal femoral rotational alignment in the Indian population - An important consideration in total knee arthroplasty. J Clin Orthop Trauma 2015; 6 (04) 240-243
• 10 Loures FB, Furtado Neto S, Pinto RdeL. et al. Rotational assessment of distal femur and its relevance in total knee arthroplasty: analysis by magnetic resonance imaging. Radiol Bras 2015; 48 (05) 282-286
• 11 Hernández-Hermoso JA, Nescolarde L, Yañez-Siller F, Calle-García J, Garcia-Perdomo D, Pérez-Andres R. Combined femoral and tibial component total knee arthroplasty device rotation measurement is reliable and predicts clinical outcome. J Orthop Traumatol 2023; 24 (01) 40
• 12 Choi YJ, Lee KW, Park JS. Early Results of Total Knee Arthroplasty Using a Built-in 3-Degree External Rotation Prosthesis. Knee Surg Relat Res 2013; 25 (03) 112-116
• 13 Romero J, Stähelin T, Binkert C, Pfirrmann C, Hodler J, Kessler O. The clinical consequences of flexion gap asymmetry in total knee arthroplasty. J Arthroplasty 2007; 22 (02) 235-240
• 14 Anouchi YS, Whiteside LA, Kaiser AD, Milliano MT. The effects of axial rotational alignment of the femoral component on knee stability and patellar tracking in total knee arthroplasty demonstrated on autopsy specimens. Clin Orthop Relat Res 1993; (287) 170-177
• 15 Nam JH, Koh YG, Kim PS, Park JH, Kang KT. Effect of the presence of the articular cartilage on the femoral component rotation in total knee arthroplasty in female and varus osteoarthritis knees. J Orthop Surg Res 2020; 15 (01) 499
• 16 Lee SS, Lee YI, Kim DU, Lee DH, Moon YW. Factors affecting femoral rotational angle based on the posterior condylar axis in gap-based navigation-assisted total knee arthroplasty for valgus knee. PLoS One 2018; 13 (05) e0197335
• 17 Tashiro Y, Uemura M, Matsuda S. et al. Articular cartilage of the posterior condyle can affect rotational alignment in total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2012; 20 (08) 1463-1469
• 18 Yang Y, Zeng X, Jin Y. et al. The Presence of Cartilage Affects Femoral Rotational Alignment in Total Knee Arthroplasty. Front Surg 2022; 9: 802631
• 19 Olcott CW, Scott RD. Determining proper femoral component rotational alignment during total knee arthroplasty. Am J Knee Surg 2000; 13 (03) 166-168
• 20 Olcott CW, Scott RD. A comparison of 4 intraoperative methods to determine femoral component rotation during total knee arthroplasty. J Arthroplasty 2000; 15 (01) 22-26