Abstract
Purpose
To evaluate the causes and modes of complications after unicompartmental knee arthroplasty (UKA) in Korean patients, and to identify the adaptability of mobile-bearing UKA for Korean patients by analyzing its complications.
Materials and Methods
Between January 2002 and December 2015, a total of 1,325 patients (1,560 cases) who underwent mobile-bearing medial UKA and were followed-up for more than 1 year were included in this study. We analyzed the complications of UKA retrospectively, and investigated the mode of complications, mean time to reoperation, and method of treatment.
Results
We observed a total of 101 complications (6.5%) after mobile-bearing UKA. The most prevalent complication was dislocation of mobile-bearing (n=52, 3.3%), accounting for more than half of the complications. Other complications include component loosening (n=16, 1.0%), progression of arthritis in lateral compartment (n=9, 0.6%), polyethylene wear and breakage (n=5, 0.3%), periprosthetic fracture (n=4, 0.3%), impingement (n=3, 0.2%), medial collateral ligament (MCL) injury (n=2, 0.1%), arthrofibrosis (n=1, 0.1%), unexplained pain (n=1, 0.1%) and infection (n=8, 0.5%). At a mean of 5.2 years post-UKA, complications occurred in our patients. The mean time interval from UKA to the development of mobile-bearing dislocation, component loosening, and progression of arthritis to the lateral compartment was a 4.3 years, 6.5 years, and 11.2 years, respectively. Complications were treated with a conversion to total knee arthroplasty in 68 cases, revision UKA in 1 case, and simple bearing change in 23 cases. Remaining complications were treated with arthroscopic management (n=3), MCL repair (n=2), open reduction and internal fixation (n=2), closed reduction and internal fixation (n=1), and manipulation (n=1).
Conclusion
The incidence of mobile-bearing dislocation after mobile-bearing UKA was especially higher in Korean patients. However, the progression of arthritis in the lateral compartment and polyethylene wear were relatively lower compared with Western counterparts. Therefore, it is encouraged that Korean patients are provided with sufficient preparation for mobile-bearing dislocation and education prior to surgery when performing mobile-bearing UKA.
REFERENCES
1. Ko YB, Gujarathi MR, Oh KJ. Outcome of unicompartmental knee arthroplasty: a systematic review of comparative studies between fixed and mobile bearings focusing on complications. Knee Surg Relat Res. 2015; 27:141–8.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
2. Lombardi AV Jr, Berend KR, Berend ME, et al. Current controversies in partial knee arthroplasty. Instr Course Lect. 2012; 61:347–81.
3. Parratte S, Pauly V, Aubaniac JM, Argenson JN. No longterm difference between fixed and mobile medial unicompartmental arthroplasty. Clin Orthop Relat Res. 2012; 470:61–8.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
4. Kim SJ, Postigo R, Koo S, Kim JH. Causes of revision following Oxford phase 3 unicompartmental knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2014; 22:1895–901.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
5. 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; 97:1493–500.
6. Lim HC, Bae JH, Song SH, Kim SJ. Oxford phase 3 unicompartmental knee replacement in Korean patients. J Bone Joint Surg Br. 2012; 94:1071–6.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
7. Yoshida K, Tada M, Yoshida H, Takei S, Fukuoka S, Nakamura H. Oxford phase 3 unicompartmental knee arthroplasty in Japan: clinical results in greater than one thousand cases over ten years. J Arthroplasty. 2013; 28:S168–71.
8. Clark M, Campbell DG, Kiss G, Dobson PJ, Lewis PL. Reintervention after mobile-bearing Oxford unicompartmental knee arthroplasty. Clin Orthop Relat Res. 2010; 468:576–80.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
9. Vardi G, Strover AE. Early complications of unicompartmental knee replacement: the Droitwich experience. Knee. 2004; 11:389–94.
10. Epinette JA, Brunschweiler B, Mertl P, Mole D, Cazenave A. French Society for Hip and Knee. Unicompartmental knee arthroplasty modes of failure: wear is not the main reason for failure: a multicentre study of 418 failed knees. Orthop Trau-matol Surg Res. 2012; 98:S124–30.
11. Pandit H, Jenkins C, Gill HS, Barker K, Dodd CA, Murray DW. Minimally invasive Oxford phase 3 unicompartmental knee replacement: results of 1000 cases. J Bone Joint Surg Br. 2011; 93:198–204.
12. Lisowski LA, Meijer LI, Bekerom MP, Pilot P, Lisowski AE. Ten- to 15-year results of the Oxford Phase III mobile unicompartmental knee arthroplasty: a prospective study from a non-designer group. Bone Joint J. 2016; 98:S41–7.
13. Emerson RH, Alnachoukati O, Barrington J, Ennin K. The results of Oxford unicompartmental knee arthroplasty in the United States: a mean ten-year survival analysis. Bone Joint J. 2016; 98:S34–40.
14. Choy WS, Kim KJ, Lee SK, Yang DS, Lee NK. Mid-term results of oxford medial unicompartmental knee arthroplasty. Clin Orthop Surg. 2011; 3:178–83.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
15. Song MH, Kim BH, Ahn SJ, Yoo SH, Lee MS. Early complications after minimally invasive mobile-bearing medial unicompartmental knee arthroplasty. J Arthroplasty. 2009; 24:1281–4.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
16. Ji JH, Park SE, Song IS, Kang H, Ha JY, Jeong JJ. Complications of medial unicompartmental knee arthroplasty. Clin Orthop Surg. 2014; 6:365–72.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
17. Kim KT, Lee S, Kim JH, Hong SW, Jung WS, Shin WS. The survivorship and clinical results of minimally invasive unicompartmental knee arthroplasty at 10-year follow-up. Clin Orthop Surg. 2015; 7:199–206.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
18. Bottomley N, Jones LD, Rout R. . A survival analysis of 1084 knees of the Oxford unicompartmental knee arthroplasty: a comparison between consultant and trainee surgeons. Bone Joint J. 2016; 98:S22–7.
19. Goodfellow J, O’Connor, Dodd C, Murray D.Goodfellow J, O'Connor J, Dodd C, Murray D, editors. Management of complications. Unicompartmental arthroplasty with the Oxford knee. 2011. Oxford: Goodfellow Publisher;p. 155–71.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
20. Kim KT, Lee S, Park HS, Cho KH, Kim KS. A prospective analysis of Oxford phase 3 unicompartmental knee arthroplasty. Orthopedics. 2007; 30:S15–8.
21. 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; 102:183–7.
Table 1
Demographics of Study
Table 2
Complications after UKA
Table 3
Incidence of Complications after Unicompartmental Knee Arthroplasty in Accordance with the Follow-Up Time
Table 4
Incidence of Bearing Dislocation after Unicompartmental Knee Arthroplasty according to the Follow-Up Time
Table 5
Incidence of Bearing Dislocation after Unicompartmental Knee Arthroplasty according to the Time Interval