Keywords
We read with interest the study entitled “Distal femoral rotational alignment in the Indian population an important consideration in total knee arthroplasty” by Tul B. Pun et al.
1
We believe that the results of the study provide contribution to the literature in terms of MRI measurements in Indian knee. However, we have few concerns about methodology and results of the study.The author analysed MRI scans of 40 knees in order to measure the angular relationships of the distal femoral rotational axes in the normal Indian population. The authors used Posterior condylar axis, transepicondylar axis, Whitesides line and Whiteside-epicondylar angle for anatomical measurement. The authors compared the PCA and W-EP angle of 40 MRI with mean age of 29.45 years. The author compared his study to other published literature.
2
, 3
, 4
, 5
Nagamine et al.2
and Mullaji et al.3
used CT scan of arthritic knees as a tool for measurement of PCA, while Yip et al.5
conducted his study on cadavers with mean age of 78years. One cannot compare angular measurements on CT,MRI and cadaveric analysis of normal and arthritic knee with heterogenous age group and different measurement modalities. The MRI uses cartilaginous joint referencing for PCA and the values between CT and MRI might not be statistically significant in normal knees, but may be misleading in valgus knees because of degeneration of the posterior femoral condyles.4
The authors did not exclude Varus/valgus malalignment of the knee which can cause inaccurate knee measurements.2
,4
We conclude that the various comparisons and conclusions drawn from the studies need to be verified and reconsidered.
Declaration of competing interest
The authors declare that there are no conflicts of interest.
Acknowledgement
Nil.
References
- Distal femoral rotational alignment in the Indian population e an important consideration in total knee arthroplasty.J Clin Orthop Trauma. 2015; 6: 240e243
- Reliability of the anteroposterior axis and the posterior condylar axis for determining rotational alignment of the femoral component in total knee arthroplasty.J Orthop Sci. 1998; 3: 194-198
- Distal femoral rotational axes in Indian knees.J Orthop Surg. 2009; 17: 166e169
- Femoral rotational alignment, based on the anteroposterior axis, in total knee arthroplasty in a valgus knee. A technical note.J Bone Joint Surg Am. 1995; 77: 1331-1334
- Distal rotational alignment of the Chinese femur and its relevance in total knee arthroplasty.J Arthroplasty. 2004; 19: 613-619
Article info
Publication history
Published online: October 13, 2019
Accepted:
September 25,
2019
Received:
September 17,
2019
Identification
Copyright
© 2019 Delhi Orthopedic Association. All rights reserved.
