MRI diagnosis of suprascapular neuropathy using spinoglenoid notch distension.

Abstract

To assess the use of a spinoglenoid notch distension measurement as a radiographic marker on MRI to aid the diagnosis of suprascapular neuropathy. Spinoglenoid notch distension was compared on MRI by blinded independent observers for two patient cohorts: one group with anelectromyography/nerve conduction study confirmed diagnosis ofsuprascapular neuropathy who underwent arthroscopic suprascapular nerve decompression, and a control group of patients aged 18-30years with a normal shoulder MRI. Sixty suprascapular nerve patients (average age 52years) were compared to 47 control patients (average age 24years). Intra-rater and inter-rater reliability showed excellent agreement between reviewers for all measurements. There was a significant difference in the mean spinoglenoid notch distension for the SSN group (m = 8.36, SD = 2.42) compared to the control group (m = 5.7, SD = 1.56); [t(212) = 9.40, p < 0.0001]. The spinoglenoid notch distension is significantly increased in patients with suprascapular neuropathy. We hypothesize that hypertrophy of the transverse scapular ligament creates a venous obstruction resulting in varicosities of the suprascapular vein which runs with the nerve under the ligament. This distends the spinoglenoid notch and can be enlarged in cases of suprascapular neuropathy which is evident on MRI.