Abstract
Purpose of the study
To document and compare the functional outcome of neutral alignment and under-correction after total knee arthroplasty (TKA) in severe varus knees of more than 15° at three and 12 months post-surgery.
Materials and methods
One hundred twenty-four consecutive patients (163 TKAs) of an average age of 61.9 years (52–79) with a pre-operative varus more than 15° were managed with jig-based TKA. Based on the post-operative mechanical femorotibial alignment (FTMA), they were categorised into three groups, namely neutral (180 + 3°), mild varus (173° to 176°) and severe varus (172° and below). The outcomes of these three groups were assessed at three and 12 months by the Oxford knee score and the WOMAC score were calculated and co-related to the extent of correction.
Results
At three months, knees in the mild varus group (n = 88) had the best results with an Oxford knee score of 41.76 + 1.44 and a WOMAC score of 19.29 + 2.93 compared to the severe varus group and the neutral alignment group which had Oxford knee scores (OKS) of 37.43 + 2.51 and 31.91 + 3.51 and WOMAC scores of 22.57 + 1.51 and 24.46 + 4.15 respectively. However at 12 months, knees in all the groups (neutral, mild varus, severe varus) had similar good functional outcomes with OKS of 39.08 + 1.68, 39.24 + 1.88, 39.29 + 1.11 and WOMAC scores of 17.42 + 2.15, 16.48 + 2.11, 16.14 + 1.21 respectively. A scatter plot done for post-operative FTMA and the functional outcome score for both scores showed a bell curve with the best outcome corresponding to a FTMA of 175° at 3 months and equal distribution for both scores at 12 months.
Conclusion
The results of our study showed that minimal under-correction gave superior functional outcomes at three months. But this advantage was temporary and both, under-correction and neutral alignment achieved equally good outcomes at one year. Considering the increased prosthesis longevity associated with neutral alignment, we propose that neutral alignment must be aimed for during TKA for knees with severe varus.
Study Design
Prospective study
Similar content being viewed by others
Abbreviations
- TKA:
-
total knee arthroplasty
- FTMA:
-
mechanical femorotibial alignment
- PACS:
-
picture archiving and communication system
- OKS:
-
Oxford knee score
- WOMAC:
-
Western University and McMaster University Osteoarthritis index
- ADL:
-
activities of daily living
References
Fang DM, Ritter MA, Davis KE (2009) Coronal alignment in total knee arthroplasty: just how important is it? J Arthroplast 24(6 Suppl):39–43
Berend ME, Ritter MA, Meding JB, Faris PM, Keating EM, Redelman R, Faris GW, Davis KE (2004) Tibial component failure mechanisms in total knee arthroplasty. Clin Orthop Relat Res ;(428):26–34
Hungerford DS (1995) Alignment in total knee replacement. Instr Course Lect 44:455–468
Lewallen DG, Bryan RS, Peterson LF (1984) Polycentric total knee arthroplasty. A ten-year follow-up study. J Bone Joint Surg Am 66(8):1211–1218
Bellemans J, Colyn W, Vandenneucker H, Victor J (2012) The Chitranjan Ranawat award: is neutral mechanical alignment normal for all patients? The concept of constitutional varus. Clin Orthop Relat Res 470(1):45–53
D'Lima DD, Chen PC, Colwell CW Jr (2001). Polyethylene contact stresses, articular congruity, and knee alignment. Clin Orthop Relat Res;(392):232–8
Howell SM, Howell SJ, Kuznik KT, Cohen J, Hull ML (2013) Does a kinematically aligned total knee arthroplasty restore function without failure regardless of alignment category? Clin Orthop Relat Res 471(3):1000–1007
Morgan SS, Bonshahi A, Pradhan N, Gregory A, Gambhir A, Porter ML (2008) The influence of postoperative coronal alignment on revision surgery in total knee arthroplasty. Int Orthop 32(5):639–642
Paley D (2003) Principles of deformity correction. Springer-verlag, Heidelberg, pp 1–60
Cooke TD, Sled EA, Scudamore RA (2007) Frontal plane knee alignment: a call for standardized measurement. J Rheumatol 34(9):1796–1801
Loures FB, Correia W, Reis JH, Pires E Albuquerque RS, de Paula Mozela A, de Souza EB, Maia PV, Barretto JM (2018) Outcomes after knee arthroplasty in extra-articular deformity. Int Orthop. https://doi.org/10.1007/s00264-018-4147-9
Rossi R, Cottino U, Bruzzone M, Dettoni F, Bonasia DE, Rosso F (2018) Total knee arthroplasty in the varus knee: tips and tricks. Int Orthop. https://doi.org/10.1007/s00264-018-4116-3Review
Puliero B, Favreau H, Eichler D, Adam P, Bonnomet F, Ehlinger M (2018) Total knee arthroplasty in patients with varus deformities greater than ten degrees: survival analysis at a mean ten year follow-up. Int Orthop. https://doi.org/10.1007/s00264-018-4019-3
Saragaglia D, Sigwalt L, Refaie R, Rubens-Duval B, Lateur G, Pailhé R (2018, 2018) Influence of the post-operative axis on the clinical results of total knee replacement for severe varus deformities: does a slight residual varus improve the results? Int Orthop. https://doi.org/10.1007/s00264-018-4092-7
Jones CA, Voaklander DC, Johnston DW, Suarez-Almazor ME (2000) Health related quality of life outcomes after total hip and knee arthroplasties in a community based population. J Rheumatol 27(7):1745–1752
Longstaff LM, Sloan K, Stamp N, Scaddan M, Beaver R (2009) Good alignment after total knee arthroplasty leads to faster rehabilitation and better function. J Arthroplast 24(4):570–578
Choong PF, Dowsey MM, Stoney JD (2009) Does accurate anatomical alignment result in better function and quality of life? Comparing conventional and computer-assisted total knee arthroplasty. J Arthroplast 24(4):560–569
Sikorski JM (2008) Alignment in total knee replacement. J Bone Joint Surg Br 90(9):1121–1127
Parratte S, Pagnano MW, Trousdale RT, Berry DJ (2010) Effect of postoperative mechanical axis alignment on the fifteen-year survival of modern, cemented total knee replacements. J Bone Joint Surg Am 92(12):2143–2149
Vanlommel L, Vanlommel J, Claes S, Bellemans J (2013) Slight undercorrection following total knee arthroplasty results in superior clinical outcomes in varus knees. Knee Surg Sports Traumatol Arthrosc 21(10):2325–2330
Magnussen RA, Weppe F, Demey G, Servien E, Lustig S (2011) Residual varus alignment does not compromise results of TKAs in patients with preoperative varus. Clin Orthop Relat Res 469(12):3443–3450
Matziolis G, Adam J, Perka C (2010) Varus malalignment has no influence on clinical outcome in midterm follow-up after total knee replacement. Arch Orthop Trauma Surg 130(12):1487–1491
Ritter MA, Faris PM, Keating EM, Meding JB (1994) Postoperative alignment of total knee replacement. Its effect on survival. Clin Orthop Relat Res;(299):153–6
Kim YH, Park JW, Kim JS, Park SD (2014) The relationship between the survival of total knee arthroplasty and postoperative coronal, sagittal and rotational alignment of knee prosthesis. Int Orthop 38(2):379–385
Czekaj J, Fary C, Gaillard T, Lustig S (2017) Does low-constraint mobile bearing knee prosthesis give satisfactory results for severe coronal deformities? A five to twelve year follow up study. Int Orthop 41(7):1369–1377. https://doi.org/10.1007/s00264-017-3452-z
Sailhan F, Jacob L, Hamadouche M (2007) Differences in limb alignment and femoral mechanical-anatomical angles using two dimension versus three dimension radiographic imaging. Int Orthop 41(10):2009–2016. https://doi.org/10.1007/s00264-017-3428-z
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
The study was performed in accordance with the ethical standards in the 1964 Declaration of Helsinki.
Conflict of interest
The authors declare that they have no conflict of interest.
Additional information
Level of Evidence: Level II
Rights and permissions
About this article
Cite this article
Rajasekaran, R.B., Palanisami, D.R., Natesan, R. et al. Minimal under-correction gives better outcomes following total knee arthroplasty in severe varus knees—myth or reality?—analysis of one hundred sixty two knees with varus greater than fifteen degrees. International Orthopaedics (SICOT) 44, 715–723 (2020). https://doi.org/10.1007/s00264-018-4240-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00264-018-4240-0