The suprascapular notch narrows with aging: a preliminary solution of the old conjecture based on a 3D-CT evaluation.

Purpose: The purpose of this study was to describe the morphology of the suprascapular notch in terms of age distribution. We hypothesized that the notch narrows with aging. Methods: Seven hundred and sixty consecutive patients (465 men and 295 women) scheduled for a shoulder surgery were retrospectively reviewed. A 3D-CT of the shoulder was taken to evaluate the shape of the notch according to the Rengachary classification. The six types of Rengachary classification were arranged into three major categories according to transverse scapular ligament ossification and notch size as follows: the wide notch (type 1 and type 2); the narrow notch (type 3 and type 4); and the ossified notch (type 5 and type 6). Comparisons between categories were done with a one-way analysis of variance. Results: There was a statistically significant difference among the three categories ( P < .01): the narrow notch group ( n = 442, 63.4 ± 12.8 years) and the ossified notch group ( n = 66, 65.9 ± 10.6 years) were significantly older than the wide notch group ( n = 252, 57.5 ± 17.8 years), respectively. In patients with Rengachary type 5 shoulders, ossification was dominant on the medial side of the notch in 37 of 39 shoulders (92.3 %). Conclusion: The current study showed that morphological changes of the scapular notch are related to aging. The narrow notch and the ossified notch are seemed to be developed from the wide notch in terms of the ossification starting from the medial side. [ABSTRACT FROM AUTHOR]