Advertisement

The severity of preoperative varus deformity affects the feasibility of correcting lower limb alignment with medial unicompartmental knee arthroplasty

Published:November 13, 2022DOI:https://doi.org/10.1016/j.jos.2022.10.017

      Abstract

      Background

      The relationship between the severity of preoperative varus deformity and the amount of its correction in unicompartmental knee arthroplasty (UKA) as well as the thickness of the insert has not been well known.

      Methods

      One hundred and three patients who underwent medial fixed-bearing UKA with the use of the spacer block method were assessed. After the component gap in extension was measured using a UKA tensor, the pre-osteotomy gap was calculated from the thickness of the bone cuts. The relationship between the preoperative hip–knee–ankle (HKA) angle as well as the pre-osteotomy gap and the amount of change in HKA angle were analysed. Also, preoperative HKA angle and the thickness of the bone cuts were compared among groups by the insert thickness.

      Results

      The mean preoperative HKA angle was 7.7 ± 3.1° varus. Patients with more varus deformity and those with a wider pre-osteotomy gap showed a more valgus change in HKA angle. As for the thickness of the insert, the preoperative HKA angle of the patients with the thinnest insert was significantly smaller (less varus) than that of those with the thicker insert while no statistically significant difference was found among the insert groups regarding the amount of the bone cuts.

      Conclusions

      The severity of the preoperative varus deformity as well as the intraoperative pre-osteotomy gap related to the amount of change in HKA angle. As thick inserts tended to be used in severe varus knees, the tibial bone cut can be reduced in such cases.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Journal of Orthopaedic Science
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Pabinger C.
        • Berghold A.
        • Boehler N.
        • Labek G.
        Revision rates after knee replacement. Cumulative results from worldwide clinical studies versus joint registers.
        Osteoarthritis Cartilage. 2013 Feb; 21: 263-268
        • Kleeblad L.J.
        • van der List J.P.
        • Pearle A.D.
        • Fragomen A.T.
        • Rozbruch S.R.
        Predicting the feasibility of correcting mechanical Axis in large varus deformities with unicompartmental knee arthroplasty.
        J Arthroplasty. 2018 Feb; 33: 372-378
        • Zhang Q.
        • Yue J.
        • Wang W.
        • Chen Y.
        • Zhao Q.
        • Guo W.
        FTFA change under valgus stress force radiography is useful for evaluating the correctability of intra-articular varus deformity in UKA.
        Arch Orthop Trauma Surg. 2018 Jul; 138: 1003-1009
        • Kozinn S.C.
        • Scott R.
        Unicondylar knee arthroplasty.
        J Bone Joint Surg Am. 1989 Jan; 71: 145-150
        • Seng C.S.
        • Ho D.C.
        • Chong H.C.
        • Chia S.L.
        • Chin P.L.
        • Lo N.N.
        • et al.
        Outcomes and survivorship of unicondylar knee arthroplasty in patients with severe deformity.
        Knee Surg Sports Traumatol Arthrosc. 2017 Mar; 25: 639-644
        • Nakano N.
        • Takayama K.
        • Kuroda Y.
        • Maeda T.
        • Hashimoto S.
        • Ishida K.
        • et al.
        Preoperative varus deformity of the knee affects the intraoperative joint gap in unicompartmental knee arthroplasty.
        Knee. 2021 Oct; 32: 90-96
        • Suda Y.
        • Takayama K.
        • Ishida K.
        • Hayashi S.
        • Hashimoto S.
        • Niikura T.
        • et al.
        Improved implant alignment accuracy with an accelerometer-based portable navigation system in medial unicompartmental knee arthroplasty.
        Knee Surg Sports Traumatol Arthrosc. 2020 Sep; 28: 2917-2923
        • Matsumoto T.
        • Muratsu H.
        • Kubo S.
        • Kuroda R.
        • Kurosaka M.
        Intra-operative joint gap kinematics in unicompartmental knee arthroplasty.
        Clin Biomech (Bristol, Avon). 2013 Jan; 28: 29-33
        • Kim S.J.
        • Bae J.H.
        • Lim H.C.
        Factors affecting the postoperative limb alignment and clinical outcome after Oxford unicompartmental knee arthroplasty.
        J Arthroplasty. 2012 Jun; 27: 1210-1215
        • Bruni D.
        • Iacono F.
        • Russo A.
        • Zaffagnini S.
        • Marcheggiani Muccioli G.M.
        • Bignozzi S.
        • et al.
        Minimally invasive unicompartmental knee replacement: retrospective clinical and radiographic evaluation of 83 patients.
        Knee Surg Sports Traumatol Arthrosc. 2010 Jun; 18: 710-717
        • Yokoyama M.
        • Nakamura Y.
        • Egusa M.
        • Doi H.
        • Onishi T.
        • Hirano K.
        • et al.
        Factors related to stress fracture after unicompartmental knee arthroplasty.
        Asia Pac J Sports Med Arthrosc Rehabil Technol. 2018 Nov 1; 15: 1-5
        • Mullaji A.B.
        • Shah S.
        • Shetty G.M.
        Mobile-bearing medial unicompartmental knee arthroplasty restores limb alignment comparable to that of the unaffected contralateral limb.
        Acta Orthop. 2017 Feb; 88: 70-74
        • Ishibashi K.
        • Sasaki E.
        • Otsuka H.
        • Kazushige K.
        • Yamamoto Y.
        • Ishibashi Y.
        Valgus correctability and meniscal extrusion were associated with alignment after unicompartmental knee arthroplasty.
        Clin Orthop Relat Res. 2020 Jul; 478: 1636-1644
        • Kreitz T.M.
        • Maltenfort M.G.
        • Lonner J.H.
        The valgus stress radiograph does not determine the full extent of correction of deformity prior to medial unicompartmental knee arthroplasty.
        J Arthroplasty. 2015 Jul; 30: 1233-1236
        • Vasso M.
        • Corona K.
        • D'Apolito R.
        • Mazzitelli G.
        • Panni A.S.
        Unicompartmental knee arthroplasty: modes of failure and conversion to total knee arthroplasty.
        Joints. 2017 Jun 5; 5: 44-50
        • Waldstein W.
        • Schmidt-Braekling T.
        • Perino G.
        • Kasparek M.F.
        • Windhager R.
        • Boettner F.
        Valgus stress radiographs predict lateral-compartment cartilage thickness but not cartilage degeneration in varus osteoarthritis.
        J Arthroplasty. 2017 Mar; 32: 788-792
        • Thienpont E.
        Conversion of a unicompartmental knee arthroplasty to a total knee arthroplasty: can we achieve a primary result?.
        Bone Joint Lett J. 2017 Jan; 99-B: 65-69
        • Böhm I.
        • Landsiedl F.
        Revision surgery after failed unicompartmental knee arthroplasty: a study of 35 cases.
        J Arthroplasty. 2000 Dec; 15: 982-989
        • McAuley J.P.
        • Engh G.A.
        • Ammeen D.J.
        Revision of failed unicompartmental knee arthroplasty.
        Clin Orthop Relat Res. 2001 Nov; 392: 279-282
        • Surendran S.
        • Kwak D.S.
        • Lee U.Y.
        • Park S.E.
        • Gopinathan P.
        • Han S.H.
        • et al.
        Anthropometry of the medial tibial condyle to design the tibial component for unicondylar knee arthroplasty for the Korean population.
        Knee Surg Sports Traumatol Arthrosc. 2007 Apr; 15: 436-442
        • Chaput C.D.
        • Weeden S.H.
        • Hyman W.A.
        • Hitt K.D.
        Mechanical bone strength of the tibial resection surface at increasing distance from the joint line in total knee arthroplasty.
        J Surg Orthop Adv. 2004 Winter; 13: 195-198
        • Small S.R.
        • Berend M.E.
        • Rogge R.D.
        • Archer D.B.
        • Kingman A.L.
        • Ritter M.A.
        Tibial loading after UKA: evaluation of tibial slope, resection depth, medial shift and component rotation.
        J Arthroplasty. 2013 Oct; 28: 179-183
        • Simpson D.J.
        • Price A.J.
        • Gulati A.
        • Murray D.W.
        • Gill H.S.
        Elevated proximal tibial strains following unicompartmental knee replacement--a possible cause of pain.
        Med Eng Phys. 2009 Sep; 31: 752-757