Related Experiment Video
Updated: Sep 16, 2025
09:01
Treatment of Ankle Osteoarthritis with Total Ankle Replacement Through a Lateral Transfibular Approach
Published on: January 24, 2018
11.9K
Posterior Tibial Slope Measurement With the Axis Estimate Method Is Not Inferior to the Established Proximal Anatomic
Michael B DiCosmo1, Alyssa M DiCosmo2, Michael J DeSarno3
1Department of Orthopaedics and Rehabilitation, University of Vermont Medical Center, Burlington, Vermont, U.S.A.
Summary
The axis estimate (AE) method for measuring posterior tibial slope (PTS) is as reliable as the standard proximal anatomic axis (PAA) method. Simpler methods like AE can improve clinical efficiency for PTS assessment.
Area of Science:
- Orthopedic surgery
- Radiology
- Biomechanics
Background:
- Accurate measurement of posterior tibial slope (PTS) is crucial for diagnosing knee pathologies and planning surgical interventions.
- The traditional proximal anatomic axis (PAA) method is considered the gold standard but is complex and time-consuming.
- Simpler, more reproducible methods for PTS measurement are needed in clinical practice.
Purpose of the Study:
- To evaluate the reliability and reproducibility of three simpler alternative methods for measuring posterior tibial slope (PTS): posterior cortical reference (PCR), anterior cortical reference (ACR), and axis estimate (AE).
- To compare these alternative methods against the established proximal anatomic axis (PAA) method using lateral knee radiographs.
Main Methods:
- Retrospective review of 155 patients (aged 18-40) with lateral knee radiographs and MRI scans.
- PTS measurements were performed by two independent raters using PAA, PCR, ACR, and AE methods.
- Inter-method, inter-rater, and intrarater reliability were assessed using intraclass correlation coefficients (ICCs).
Main Results:
- The axis estimate (AE) method showed no significant difference compared to the PAA method (10.3°, P = .09).
- The anterior cortical reference (ACR) and posterior cortical reference (PCR) methods showed significant differences from the PAA method (11.7°, P < .0001 and 7.5°, P < .0001, respectively).
- All methods demonstrated moderate reliability (ICCs, 0.5-0.74), with excellent inter-method ICC for AE and PAA (ICC, 0.87).
Conclusions:
- The axis estimate (AE) method is a reliable and reproducible alternative to the proximal anatomic axis (PAA) method for measuring posterior tibial slope (PTS).
- The ACR and PCR methods are not interchangeable with the PAA method due to significant differences in measurements.
- The AE method offers a simpler approach, potentially increasing its clinical utilization and maintaining measurement performance.
