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Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty
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Midlevel Constraint Without Stem Extensions in Primary Total Knee Arthroplasty Provides Stability Without
David A Crawford1, Jesua I Law2, Adolph V Lombardi3
1Joint Implant Surgeons, Inc., New Albany, OH; Mount Carmel Health System, New Albany, OH.
The Journal of Arthroplasty
|April 30, 2018
Summary
Midlevel constraint (MLC) bearings in primary total knee arthroplasty (TKA) demonstrate promising early outcomes, with significant improvements in function and range of motion. These bearings show good survivorship, particularly in complex cases, with low revision rates.
Area of Science:
- Orthopedic surgery
- Biomedical engineering
Background:
- Total knee arthroplasty (TKA) systems often incorporate midlevel constraint (MLC) articular bearings for primary implant use.
- Early outcomes of MLC bearings in primary TKA require further investigation.
Purpose of the Study:
- To report early outcomes of primary total knee arthroplasty (TKA) utilizing midlevel constraint (MLC) articular bearings.
Main Methods:
- A retrospective study of 96 patients (103 TKAs) using the Vanguard Total Knee System with MLC bearings.
- Minimum 2-year follow-up (mean 5 years) assessing pain, Knee Society scores, range of motion, and revision rates.
Main Results:
- Significant improvements in range of motion (103° to 113°) and Knee Society scores (clinical: 28 to 88; functional: 43 to 62).
- Low revision rate of 3% (patellar tendon rupture, stiffness, infection); 9.9% required manipulation.
- No aseptic loosening or instability observed, even in cases with ligamentous compromise.
Conclusions:
- Midlevel constraint (MLC) bearings show good survivorship in primary TKA, especially in complex cases with ligamentous instability.
- MLC bearings are a viable option for primary TKA, offering functional improvement and stability.
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