Review Question - QID 218848

This patient’s MRI shows a large cyst adjacent to the transverse scapular ligament (i.e. suprascapular notch) which would result in suprascapular neuropathy with weakness in both the supraspinatus and infraspinatus. Physical examination manifestations would include weakness in performing Jobe’s test compared to the unaffected contralateral side.

Suprascapular neuropathy was first described nearly a century ago and has been increasingly recognized with advancements in diagnostic modalities. Patients typically present with deep posterior shoulder pain and weakness in shoulder abduction (supraspinatus) and/or external rotation (infraspinatus). The two classic areas of compression are: (1) at the suprascapular notch as the nerve traverses under the transverse scapular ligament and (2) at the spinoglenoid notch as it courses in close proximity to the glenohumeral joint. Compression at the suprascapular notch results in posterior shoulder pain with supraspinatus AND infraspinatus dysfunction. Compression at the downstream spinoglenoid notch results in pain with isolated infraspinatus dysfunction, as the supraspinatus is innervated proximal to this area of compression. If either injury is chronic in nature, muscle wasting can be appreciated with underlying fatty infiltration on magnetic resonance imaging (MRI). Collectively, the physical examination, MRI, and electromyography (EMG) findings can facilitate establishing the diagnosis of suprascapular neuropathy.

Kim and colleagues performed a retrospective review of spinoglenoid cysts treated with SLAP repair alone versus SLAP repair and direct cyst decompression. They found that the visual analog scale and Rowe and Constant scores significantly improved after surgery in both groups, however, results were not significant when compared between each group. The authors concluded that direct decompression of spinoglenoid cysts did not lead to differences in postoperative outcomes and SLAP tears were the direct cause of spinoglenoid cyst formation.

Schroeder and colleagues performed a larger systematic review of spinoglenoid cysts treated with SLAP repair alone versus SLAP repair and direct cyst decompression. They similarly found significant post-operative improvements in the visual analog scale and Rowe and Constant scores, however without a significant difference in improvement between both groups. They concluded that spinoglenoid cyst decompression does not provide added value in this patient population.

Figure A shows an MRI with a large cyst traversing above and below the scapular spine at the area of the suprascapular notch.

Incorrect Answers:
Answer 1: The Anterior Load and Shift test evaluates for anterior shoulder instability. The test is performed by having the patient lie supine with the shoulder at 40-60 degrees of abduction and forward flexion. Axially load the humerus into the glenoid fossa and apply anterior translation forces. It is positive if there is increased translation compared to the contralateral side. This examination would be expectedly normal in this patient.
Answer 2: The Bear Hug Test evaluates for subscapularis weakness. It is performed by having the patient place the ipsilateral palm on the opposite deltoid and attempt to resist the examiner pulling their hand away anteriorly. The test is positive with considerable weakness compared to the contralateral side. This examination would be expectedly normal in this patient.
Answer 4: The Hornblower’s Sign evaluates for teres minor weakness. The test is performed by bringing the patient’s shoulder to 90 degrees of abduction, 90 degrees of external rotation, and asking the patient to hold this position. This test is positive if the arm falls into internal rotation. This examination would be expectedly normal in this patient.
Answer 5: The Kim Test evaluates for posterior shoulder instability. The test is performed by having the patient seated, arm at 90° abduction, followed by flexing the shoulder to 45 forward flexion while simultaneously applying axial load on the elbow & posterior-inferior force on the upper humerus. The test is positive with palpable subluxation or pain compared to the contralateral side. This examination would be expectedly normal in this patient.