The Lateral Capitellohumeral Angle in Normal Children: Mean, Variation, and Reliability in Comparison to Baumann’s Angle

Author(s): Shank CF, Waiter BP, Pace JL, Jinguji TM, Schmale GA, Bittne, RCL., Bompadre V, Stults JK and Krengel WF

Source: J Pediatr Orthop 31(3):266-271 , 2011.

Summary:
Supracondylar humerus fractures are difficult to treat and malunion is common.  The authors attempted to measure the lateral capitellohumeral angle as an indicator of sagittal alignment.  In addition, the authors compared this measurement to Baumann’s angle, which an accepted measure of coronal plane deformity.  The lateral capitellohumeral angle is the angulation between the humeral shaft and capitellar physis.   This angle may be more accurate and descriptive of distal humeral sagittal plane alignment than the standard anterior humeral line through the capitellium ossification center.  The anterior humeral line has been shown to vary with age and degree ossification.
 
The authors’ retrospectively reviewed children between the ages of 0-12 with regards to the lateral capitellohumeral angle and Baumann’s angle.  Intra and Inter reliability measurements were performed.  Unfortunately, all elbows appeared to be uninjured, which confounds their interpretation.  The results demonstrate intra-observer and inter-observer reliability of both angles.  The reliability varied somewhat with age and the Baumann’s angle was more reliable. 
 
The authors discuss the various measurements of sagittal and coronal malalignment.  The sagittal alignment remodels slowly, although it tends to improve over time.  The authors advocate the lateral humeral capitellar angle as a measure to establish and follow sagittal alignment.  As stated previously, this measure needs to be assessed on injured elbows to substantiate its reliability.