Suprascapular Nerve Entrapment: Current Concepts and Recent Advances.

INTRODUCTION

The suprascapular nerve is inherently vulnerable to entrapment, as it is relatively constrained by its surrounding anatomy: proximally crossing the suprascapular notch; or more distally over the spinoglenoid notch. Despite this, suprascapular nerve entrapment is relatively uncommon, and has until recently been an underappreciated cause of shoulder pain and dysfunction.

CAUSES AND ASSESSMENT

Aetiology is typically due to traction or compression nerve injury, and a number of high-risk variants in anatomy have now been described. The symptoms are best investigated with magnetic resonance imaging and electrodiagnostic evaluation, with X-ray, ultrasound and CT scans useful in excluding common differential diagnoses, and possible future roles for MR neurography and diagnostic suprascapular nerve block.

MANAGEMENT

The majority of patients respond well to non-operative management, with a multimodal non-operative approach thought to optimise outcomes. The role of neuromodulation in non-operative management continues to evolve, but has shown promising early results. For patients with a clear compressive structural lesion, or where symptoms are refractory to non-operative management, surgery is required. There are now well-established techniques for both arthroscopic and open approaches to suprascapular and spinoglenoid decompression. Outcomes from isolated suprascapular nerve decompression have been consistently impressive, but the use of suprascapular nerve decompression as an adjunct to associated rotator cuff repair or stabilisation procedures had been observed to attracted a relatively high rate of complication, prompting speculation that it may be advisable to maintain a high threshold for adjunct nerve decompression procedures: where there is known suprascapular nerve neuropathy or the presence of high-risk anatomical variants.