Does the overhang of tibial component in fixed bearing medial unicondylar knee arthroplasty affect 1-year results?
Keywords:Unicondylar, Knee, Arthroplasty, Function, Implant size
Aim: Unicondylar knee arthroplasty (UKA) is an effective treatment for single-compartment knee arthrosis. The compatibility of the size of the components with the bone is one of the factors determining patient satisfaction. With this study we aimed to investigate the effect of size concordance of the tibial component and bone in fixed bearing UKA on functional scores and pain.
Methods: Demographic data, preoperative and postoperative 1-year visual analog pain scale (VAS) and Oxford Knee Scores (OKS) were collected from 43 patients operated by a single surgeon with a fixed bearing UKA implant (Zimmer UKA, Warsaw USA) for this prospective cohort study. Patients were then grouped according to radiological compliance of the tibial component to the bone as perfect match or overhang, and the groups were compared in terms of pain and functional scores.
Results: Among 43 patients included in the study, 9 (20.9%) were males and 34 (79.1%) were females. The mean age of the patients was 62.1 (8.1) years. The median VAS and OKS scores of the patients before surgery were 6 (3-8) and 26 (21-30), respectively. Postoperatively, VAS score decreased to 1 (0-2), while OKS increased to 44 (37-48) (P<0.001 for both). There were only 3 patients with underhang. Twenty-two (52.1%) patients had perfect match and 18 (41.9%) had an overhang from the bone surface. There was no patient with an overhang greater than 3mm. The VAS and OKS scores at post-operative 1-year of 18 patients with overhang and 22 patients without bone overhang were similar (P=0.674 and P=0.873, respectively).
Conclusion: The overhang of the tibial component in fixed bearing unicondylar knee arthroplasty is common, however, this does not affect functional results in 1-year follow-up. Nevertheless, the sizing of the component should be checked by adequate means.
Murray DW, Parkinson RW. Usage of unicompartmental knee arthroplasty. Bone Jt J. 2018;100-B:432–5.
Winnock de Grave P, Barbier J, Luyckx T, Ryckaert A, Gunst P, Van den Daelen L. Outcomes of a Fixed-Bearing, Medial, Cemented Unicondylar Knee Arthroplasty Design: Survival Analysis and Functional Score of 460 Cases. J Arthroplasty. 2018;33(9):2792–9. doi: 10.1016/j.arth.2018.04.031
Alnachoukati OK, Barrington JW, Berend KR, Kolczun MC, Emerson RH, Lombardi AV, Mauerhan DR. Eight Hundred Twenty-Five Medial Mobile-Bearing Unicompartmental Knee Arthroplasties: The First 10-Year US Multi-Center Survival Analysis. J Arthroplasty. 2018;33(3):677–83. doi: 10.1016/j.arth.2017.10.015
Emerson RH, Alnachoukati O, Barrington J, Ennin K. The results of Oxford unicompartmental knee arthroplasty in the United States. J BONE Jt Surg. 2006;34–40.
Chou DTS, Swamy GN, Lewis JR, Badhe NP. Revision of failed unicompartmental knee replacement to total knee replacement. Knee. 2012 Aug;19(4):356–9.
Kamenaga T, Hiranaka T, Kikuchi K, Hida Y, Fujishiro T, Okamoto K. Influence of tibial component rotation on short-term clinical outcomes in Oxford mobile-bearing unicompartmental knee arthroplasty. Knee. 2018;25(6):1222–30. doi: 10.1016/j.knee.2018.06.016
Nielsen CS, Nebergall A, Huddleston J, Kallemose T, Malchau H, Troelsen A. Medial Overhang of the Tibial Component Is Associated With Higher Risk of Inferior Knee Injury and Osteoarthritis Outcome Score Pain After Knee Replacement. J Arthroplasty. 2018;33(5):1394–8. doi: 10.1016/j.arth.2017.12.027
Simsek ME, Akkaya M, Gursoy S, Isik C, Zahar A, Tarabichi S, Bozkurt M. Posterolateral overhang affects patient quality of life after total knee arthroplasty. Arch Orthop Trauma Surg. 2018;138(3):409–18. doi: 10.1007/s00402-017-2850-4
Tuğay BU, Tuğay N, Güney H, Kinikli GI, Yüksel I, Atilla B. Oxford knee score: Cross-cultural adaptation and validation of the turkish version in patients with osteoarthritis of the knee. Acta Orthop Traumatol Turc. 2016;50(2):198–206.
Fitz W, Bliss R, Losina E. Current fit of medial and lateral unicompartmental knee arthroplasty. Acta Orthop Belg. 2013;79(2):191–6.
Kennedy JA, Palan J, Mellon SJ, Esler C, Dodd CAF, Pandit HG, Murray DW. Most unicompartmental knee replacement revisions could be avoided: a radiographic evaluation of revised Oxford knees in the National Joint Registry. Knee Surgery, Sport Traumatol Arthrosc. 2020; doi: 10.1007/s00167-020-05861-5
Chau R, Gulati A, Pandit H, Beard DJ, Price AJ, Dodd CAF, Gill HS, Murray DW. Tibial component overhang following unicompartmental knee replacement-Does it matter? Knee. 2009;16(5):310–3. doi: 10.1016/j.knee.2008.12.017
Saffarini M, Nover L, Tandogan R, Becker R, Moser LB, Hirschmann MT, Indelli PF. The original Akagi line is the most reliable: a systematic review of landmarks for rotational alignment of the tibial component in TKA. Knee Surg Sports Traumatol Arthrosc. 2019 Apr;27(4):1018–27.
Kamenaga T, Hiranaka T, Hida Y, Fujishiro T, Okamoto K. Rotational position of the tibial component can decrease bony coverage of the tibial component in Oxford mobile-bearing unicompartmental knee arthroplasty. Knee. 2019;26(2):459–65. doi: 10.1016/j.knee.2019.01.003
Leenders AM, Schotanus MGM, Wind RJP, Borghans RAP, Kort NP. A high rate of tibial plateau fractures after early experience with patient-specific instrumentation for unicompartmental knee arthroplasties. Knee Surgery, Sport Traumatol Arthrosc. 2018;26(11):3491–8. doi: 10.1007/s00167-018-4956-9
Escudier JC, Jacquet C, Flecher X, Parratte S, Ollivier M, Argenson JN. Better Implant Positioning and Clinical Outcomes With a Morphometric Unicompartmental Knee Arthroplasty. Results of a Retrospective, Matched-Controlled Study. J Arthroplasty. 2019;34(12):2903–8. doi: 10.1016/j.arth.2019.07.031
Alvand A, Khan T, Jenkins C, Rees JL, Jackson WF, Dodd CAF, Murray DW, Price AJ. The impact of patient-specific instrumentation on unicompartmental knee arthroplasty: a prospective randomised controlled study. Knee Surgery, Sport Traumatol Arthrosc. 2018;26(6):1662–70.
Bizzozero P, Bulaid Y, Flecher X, Ollivier M, Parratte S, Argenson JN. Morphometric Tibial Implant Decreases Posterior Overhang Rate and Improves Clinical Outcomes: Results of a Prospective, Matched Controlled Study. J Arthroplasty. 2018;33(9):2804–9.
Berger RA, Della Valle CJ. Unicompartmental knee arthroplasty: indications, techniques, and results. Instr Course Lect. 2010;59:47–56.
Barbadoro P, Ensini A, Leardini A, d’Amato M, Feliciangeli A, Timoncini A, Amadei F, Belvedere C, Giannini S. Tibial component alignment and risk of loosening in unicompartmental knee arthroplasty: a radiographic and radiostereometric study. Knee Surgery, Sport Traumatol Arthrosc. 2014;22(12):3157–62.
Gudena R, Pilambaraei MA, Werle J, Shrive NG, Frank CB. A Safe Overhang Limit for Unicompartmental Knee Arthroplasties Based on Medial Collateral Ligament Strains. An In Vitro Study. J Arthroplasty. 2013;28(2):227–33. doi: 10.1016/j.arth.2012.05.019
Abram SGF, Marsh AG, Brydone AS, Nicol F, Mohammed A, Spencer SJ. The effect of tibial component sizing on patient reported outcome measures following uncemented total knee replacement. Knee. 2014;21(5):955–9. doi: 10.1016/j.knee.2014.05.010
Ahmed I, Paraoan V, Bhatt D, Mishra B, Khatri C, Griffin D, Metcalfe A, Barlow T. Tibial component sizing and alignment of TKR components does not significantly affect patient reported outcome measures at six months. A case series of 474 participants. Int J Surg. 2018;52(February):67–73.
McArthur J, Makrides P, Thangarajah T, Brooks S. Tibial component overhang in total knee replacement: Incidence and functional outcomes. Acta Orthop Belg. 2012;78(2):199–202.
van der List JP, Chawla H, Zuiderbaan HA, Pearle AD. The Role of Preoperative Patient Characteristics on Outcomes of Unicompartmental Knee Arthroplasty: A Meta-Analysis Critique. J Arthroplasty. 2016;31(11):2617–27. doi: 10.1016/j.arth.2016.04.001
Kim KT, Lee S, Lee J Il, Kim JW. Analysis and Treatment of Complications after Unicompartmental Knee Arthroplasty. Knee Surg Relat Res. 2016 Mar;28(1):46–54.
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