Early Results of Oxford Mobile Bearing Medial Unicompartmental Knee Replacement (UKR) with the Microplasty Instrumentation: An Indian Experience

Document Type : RESEARCH PAPER

Authors

1 Department of Orthopaedics, All India Institute of Medical Sciences (AIIMS), New Delhi, India

2 Orthopaedics and Honorary Consultant, Chapel Allerton Hospital, University of Leeds, UK

Abstract

Background: Oxford medial unicompartmental knee replacement (UKR) is indicated in patients with anteromedial
osteoarthritis (AMOA) of the knee. Microplasty (MP) instrumentation was introduced in 2012 as an improvement over
phase 3 instrumentation. Advantages of this instrumentation include conservative tibial cut, decreased tibial re-cut rate
and improved component alignment. We report the results of UKR with the new instrumentation in a consecutive series
with a minimum follow-up of 2 years.
Methods: A prospective study of 115 cemented medial Oxford UKRs implanted in 89 patients was done. Postoperative
alignment of the tibial and femoral components was analysed. Patient reported outcome measures were
recorded using Oxford Knee Score (OKS) and the American Knee Society Score (KSS). Tegner Activity Scale (TAS)
was used to record the activity level.
Results: 115 consecutive medial Oxford UKRs were studied. All patients were followed up annually in this prospective
ethically approved study. The mean follow-up was 36 months and the minimum follow-up was 25 months. No patient
died and none were lost to follow-up. At the final follow-up, the average OKS of the cohort was 39.5 (SD: 5.7). 91.2 % of
the patients had good or excellent OKS with only 3.5 % reporting poor OKS. The overall limb alignment was 4.80 varus
(0 – 140 varus). Tibia was recut in 5.2 % of cases. Median bearing size was 3 (range: 3 to 6). There was one case of
bearing dislocation and one case of aseptic tibial loosening.
Conclusion: This is the first study to report results of MP instrumentation at a minimum follow-up of 2 years. Our study
indicates that the new instrumentation results in reliable and accurate implantation of femoral and tibial components in
majority of the cases, with a decrease in number of alignment outliers, and also a reduced rate of bearing dislocation.

Keywords

Main Subjects

References

1. White SH, Ludkowski PF, Goodfellow JW.
Anteromedial osteoarthritis of the knee. J Bone Joint
Surg Br. 1991; 73(4):582-6.
2. Jackson WF, Berend KR, Spruijt S. 40 years of the
Oxford knee. Bone Joint J. 2016; 98-B(10 Supple
B):1-2.
3. Goodfellow JW, O’Connor J. Clinical results of the
Oxford knee. Surface arthroplasty of the tibiofemoral
joint with a meniscal bearing prosthesis. Clin Orthop
Relat Res. 1986; 205(1):21-42.
4. Price AJ, O’Connor JJ, Murray DW, Dodd CA, Goodfellow
JW. A history of Oxford unicompartmental knee
arthroplasty. Orthopedics. 2007; 30(5 Suppl):7-10.
5. Hurst JM, Berend KR. Mobile-bearing unicondylar
knee arthroplasty: the Oxford experience. Orthop
Clin North Am. 2015; 46(1):113-24.
6. Price AJ, Svard U. A second decade lifetable
survival analysis of the Oxford unicompartmental
knee arthroplasty. Clin Orthop Relat Res. 2011;
469(1):174-9.
7. Price AJ, Waite JC, Svard U. Long-term clinical
results of the medial Oxford unicompartmental
knee arthroplasty. Clin Orthop Relat Res. 2005;
435(1):171-80.
8. Pandit H, Hamilton TW, Jenkins C, Mellon SJ, Dodd
CA, Murray DW. The clinical outcome of minimally
invasive Phase 3 Oxford unicompartmental knee
arthroplasty: a 15-year follow-up of 1000 UKAs.
Bone Joint J. 2015; 97-B(11):1493-500.
9. Berger RA, Meneghini RM, Jacobs JJ, Sheinkop
MB, Della Valle CJ, Rosenberg AG, et al. Results of
unicompartmental knee arthroplasty at a minimum
of ten years of follow-up. J Bone Joint Surg Am. 2005;
87(5):999-1006.
10. Koh IJ, Kim JH, Jang SW, Kim MS, Kim C, In Y. Are
the Oxford(®) medial unicompartmental knee
arthroplasty new instruments reducing the bearing
dislocation risk while improving components
relationships? A case control study. Orthop
Traumatol Surg Res. 2016; 102(2):183-7.
11. Tu Y, Xue H, Ma T, Wen T, Yang T, Zhang H, et al.
Superior femoral component alignment can be
achieved with Oxford microplasty instrumentation
after minimally invasive unicompartmental knee
arthroplasty. Knee Surg Sports Traumatol Arthrosc.
2017; 25(3):729-35.
12. Walker T, Heinemann P, Bruckner T, Streit MR, Kinkel
S, Gotterbarm T. The influence of different sets of
surgical instrumentation in Oxford UKA on bearing
size and component position. Arch Orthop Trauma
Surg. 2017; 137(7):895-902.
13. Jang KM, Lim HC, Han SB, Jeong C, Kim SG, Bae JH.
Does new instrumentation improve radiologic
alignment of the Oxford® medial unicompartmental
knee arthroplasty? Knee. 2017; 24(3):641-50.
14. Hurst JM, Berend KR, Adams JB, Lombardi AV
Jr. Radiographic comparison of mobile-bearing
partial knee single-peg versus twin-peg design. J
Arthroplasty. 2015; 30(3):475-8.
15. Inui H, Taketomi S, Yamagami R, Sanada T,
Shirakawa N, Tanaka S. Impingement of the
mobile bearing on the lateral wall of the tibial
tray in unicompartmental knee arthroplasty. J
Arthroplasty. 2016; 31(7):1459-64.
16. Mukherjee K, Pandit H, Dodd CA, Ostlere S,
Murray DW. The Oxford unicompartmental knee
arthroplasty: a radiological perspective. Clin Radiol.
2008; 63(10):1169-76.
17. Gulati A, Chau R, Pandit HG, Gray H, Price AJ,
Dodd CA, et al. The incidence of physiological
radiolucency following Oxford unicompartmental
knee replacement and its relationship to outcome. J
Bone Joint Surg Br. 2009; 91-B(7):896-902.
18. Price AJ, Webb J, Topf H, Dodd CA, Goodfellow
JW, Murray DW. Rapid recovery after oxford
unicompartmental arthroplasty through a short
incision. J Arthroplasty. 2001; 16(8):970-6.
19. White SH, Roberts S, Jones PW. The twin peg Oxford
partial knee replacement: the first 100 cases. Knee.
2012; 19(1):36-40.
20. White SH, Roberts S, Kuiper JH. The cemented twinpeg
Oxford partial knee replacement survivorship: a
cohort study. Knee. 2015; 22(4):333-7.
21. Goodfellow J, O’Connor J, Pandit H, Dodd C, Murray
D. Unicompartmental arthroplasty with the Oxford
knee. New York: Goodfellow Publishers Limited;
2011.
22. Pandit H, Jenkins C, Barker K, Dodd CA, Murray
DW. The Oxford medial unicompartmental knee
replacement using a minimally-invasive approach. J
Bone Joint Surg Br. 2006; 88(1):54-60.
23. Panzram B, Bertlich I, Reiner T, Walker T, Hagmann
S, Weber MA, et al. Results after cementless medial
Oxford unicompartmental knee replacementincidence
of radiolucent lines. PLoS One. 2017;
12(1):e0170324.
24. Pandit H, Jenkins C, Beard DJ, Gallagher J, Price AJ,
Dodd CA, et al. Cementless Oxford unicompartmental
knee replacement shows reduced radiolucency at
one year. J Bone Joint Surg Br. 2009; 91(2):185-9.
The Archives of Bone and Joint Surgery
Volume 6, Issue 4
July 2018
Pages 301-311

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History

  • Receive Date: 01 January 2018
  • Revise Date: 21 January 2018
  • Accept Date: 23 January 2018

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