The presentation discusses an important paper about the risks and benefits of doing bilateral simultaneous and staged total knee replacements. The findings of the study are presented in a comprehensive manner

1. Bilateral
Simultaneous Vs Staged
TKR
Dr Vaibhav Bagaria
Hip & Knee Surgeon
Sir HN Reliance Foundation Hospital
Mumbai, India

2. Complications

4. PRACTICE CHANGING
PAPER
• Path Breaking or Path Illuminating: Answers a
Burning Question
• Sufficient Numbers
• Representative Sample
• Good Analysis
• Unbiased Discussion

5. Double Trouble
Trouble Doubled Over
OR

6. Paper that answers a
Burning Question

7. Introduction
• Brings out the controversy surrounding the
subject!
• Cites Relevant paper suggesting conflicting
opinion!

8. The Controversy
• Advantages
• Disadvantages

9. The double trouble Side
• Higher 90 day Mortality
• Higher Procedure related complications
• Higher Rehabilitation Cost

10. Trouble is doubled Up!
• Decreased Rehabilitation Time
• Less Expensive
• Functionally Superior

11. The conflict
• Few studies have specifically considered
whether cumulative, per person complication
rate following staged unilateral procedures
exceed that of bilateral simultaneous surgery.

12. Previous Literature Divided

13. For Simultaneous

14. Throws in Meta-analysis &
systemic Reviews

15. Only to Trash Them
•“Hampered by
difference in
baseline
characteristics of
the patients,
surgeon
preference and
hospital
characteristic”

16. Clear Aim
• The purpose of this study was to compare the
complications and mortality between BTKA -
Simultaneous and BTKA - Staged while
adjusting these differences!

17. Data Set
• Integrated Healthcare System total join
arthroplasty Registry ( Kaiser Permanente
Total Joint Registry)
• Identified Cohort of patients with primary
elective bilateral TKA 17 -04 -2001 to 28 - 12
-2012
• 11,118 individuals( 22, 236 implants) from 43
medical centres in 4 US geographical regions

18. Data Sub Set
• For outcomes related to death and other
complications a subsample of patients
between Nov 04 and Dec 12 included
because of availability of extensive
comorbidity information was only available
during this period.
• 7991 individuals, 42 Med centres, 271
Surgeons

19. Data Set
• Standardised Forms - Validated
• ICD definition (9th revision) used for Elixhauser
comorbidity & Outcomes
• The only exposure variable of interest was based
on whether 2 joints were replaced on same day
or on different days but after 90 days and less
than 1 year.
• Confounding variables listed in 2 tables

20. Outcomes Measured
• Aseptic Loosening
• Septic Revision/ Deep SSI
• Death
• Acute MI
• Stroke
• VTE
The latter 4 considered within
90 days of index procedure

21. 11,118 patients

22. Subset of 7991 individuals

23. Modelling Approach
• Consisted of fitting between within models with normal
cross classified random intercept effects - > Non
hiererarchial
• Disassociate surgeon and facility from the procedure itself
to avoid confounding by stable surgeon and facility factor.
• Missing data handled with multiple imputations with
chained equations ( MICE)
• Propensity Score weights were calculated separately for
each imputed data

24. Results

25. Results
• Over all the complication & death in both the
groups were rare.
• The complication rates in BTKA -
Simulataneous and BTKA Staged were
comparable.

26. Adjusted Model - 1

27. Adjusted Model 2

28. Result
•Insufficient Evidence that death or complications
were increased among BTKA - Simultaneous
relative to BTKA - Staged

29. Discussions
• Over all rate of major medical complications
including mortality, acute MI, VTE or stroke
were relatively low in both BTKA -
Simultaneous and Staged groups.
• No difference in both groups

30. Limitation
• Miscoding of comorbidity in EMR
• Study not designed to identify risk factors for
specific Complication
• Cannot make any recommendation regarding
Patient Selection

31. Strengths
• Large sample size
• Prospectively Collected data
• Robust Outcome Verification process
• EMR - > rich array of comorbidity info
• Eliminates Selction bais that may have creeped by
using propensity score weighting ensuring that the
difference in groups because of measured variables
were minimised.

32. So .. Did it
• Change my Practice?
• Was it - Path Breaking or Path illuminating?

33. Thank You
Sir HN Reliance Foundation Hospital
Est 1925