Epidemiology of Bearing Dislocations After Mobile-Bearing Unicompartmental Knee Arthroplasty

Multicenter Analysis of 67 Bearing Dislocations

MUKA Study group

Research output: Contribution to journalArticle

Abstract

Background: This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases. Methods: We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort. Results: There were 67 (3.6%) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55% of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs. Conclusion: Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases. Level of Evidence: IV, Case series.

Original languageEnglish
JournalJournal of Arthroplasty
DOIs
Publication statusAccepted/In press - 2019 Jan 1

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Knee Replacement Arthroplasties
Epidemiology
Incidence
Surgeons

Keywords

  • arthroplasty
  • bearing dislocation
  • knee
  • mobile
  • Oxford
  • unicompartmental

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

@article{1c5cadc52d814675b3117c8a2d1fa551,
title = "Epidemiology of Bearing Dislocations After Mobile-Bearing Unicompartmental Knee Arthroplasty: Multicenter Analysis of 67 Bearing Dislocations",
abstract = "Background: This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases. Methods: We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort. Results: There were 67 (3.6{\%}) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55{\%} of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs. Conclusion: Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases. Level of Evidence: IV, Case series.",
keywords = "arthroplasty, bearing dislocation, knee, mobile, Oxford, unicompartmental",
author = "{MUKA Study group} and Bae, {Ji Hoon} and Kim, {Jae Gyoon} and Lee, {Seung Yup} and Lim, {Hong Chul} and Yong In and Song Lee and Ji, {Jong Hun} and Lee, {Ju Hong} and Kim, {Jong Min} and Kim, {Kang Il}",
year = "2019",
month = "1",
day = "1",
doi = "10.1016/j.arth.2019.08.004",
language = "English",
journal = "Journal of Arthroplasty",
issn = "0883-5403",
publisher = "Churchill Livingstone",

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TY - JOUR

T1 - Epidemiology of Bearing Dislocations After Mobile-Bearing Unicompartmental Knee Arthroplasty

T2 - Multicenter Analysis of 67 Bearing Dislocations

AU - MUKA Study group

AU - Bae, Ji Hoon

AU - Kim, Jae Gyoon

AU - Lee, Seung Yup

AU - Lim, Hong Chul

AU - In, Yong

AU - Lee, Song

AU - Ji, Jong Hun

AU - Lee, Ju Hong

AU - Kim, Jong Min

AU - Kim, Kang Il

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Background: This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases. Methods: We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort. Results: There were 67 (3.6%) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55% of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs. Conclusion: Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases. Level of Evidence: IV, Case series.

AB - Background: This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases. Methods: We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort. Results: There were 67 (3.6%) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55% of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs. Conclusion: Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases. Level of Evidence: IV, Case series.

KW - arthroplasty

KW - bearing dislocation

KW - knee

KW - mobile

KW - Oxford

KW - unicompartmental

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U2 - 10.1016/j.arth.2019.08.004

DO - 10.1016/j.arth.2019.08.004

M3 - Article

JO - Journal of Arthroplasty

JF - Journal of Arthroplasty

SN - 0883-5403

ER -