Paralysis of the trapezius muscle: evaluation and surgical management

Abstract

Background: Paralysis of the trapezius muscle most commonly results from iatrogenic injury to the spinal accessory nerve.

Methods: The clinical presentation and physical examination findings of trapezius palsy have been well characterized, but unfortunately the diagnosis of this condition is oftentimes missed or delayed, sometimes leading to unnecessary surgery on the rotator cuff or tendon of the long head of the biceps.

Results: The diagnosis can be confirmed using electromyography with nerve conduction studies. Although nonoperative treatment may help some patients with temporary neurapraxia of the spinal accessory nerve, nerve repair with or without nerve grafting should be performed soon for patients suspected of a nerve transection. Nerve transfers can be considered within the first year after the injury when nerve repair and grafting cannot be completed. For chronic trapezius palsy, transfer of the levator scapulae and rhomboids has been refined and represents a very successful surgical procedure. Rarely, scapulothoracic arthrodesis is considered for individuals with failed tendon transfers or multiple nerve involvement.

Conclusion: Trapezius palsy is oftentimes missed. An accurate diagnosis allows consideration of various treatment modalities that have been reported to provide good outcomes for properly selected patients.

Keywords: Eden-Lange; Iatrogenic injury; Levator scapulae; Muscle paralysis; Rhomboids; Spinal accessory nerve; Trapezius; Trapezius palsy.

Figure 1

(A) Anatomy of the trapezius muscle (B) and spinal accessory nerve (cranial nerve XI). (C) Schematic representation of the mechanical function of the trapezius.

Figure 2

Physical examination findings in patients with trapezius palsy (Right side). (A) Increased distance between midline and scapula in the resting position. (B) Limited active abduction. (C) Inability to properly shrug. (D) Weakness of scapular retraction against resistance. (E) Scapular flip sign.

Figure 3

Plain anteroposterior (A) and axillary (B) radiographs show very lateral position of the scapula in reference to the chest wall, in addition to metallic anchors for rotator cuff surgery that retrospectively had been unnecessary. (C) Magnetic resonance may show atrophy and fatty infiltration of the Right Upper trapezius () compared to the Left Upper trapezius ().

Figure 4

Schematic representation of (A) the 3 portions of the trapezius, (B) transfer of the levator and rhomboids according to Eden and Lange, and (C) the Elhassan modification of this procedure.

Figure 5

Levator scapulae and rhomboids transfer. (A) Curvilinear skin incision with elevation of a large subcutaneous flap. (B) Harvested levator scapulae and rhomboids. (C) Completed transfer.

Figure 6

Postoperative radiographs after scapulothoracic arthrodesis. (A) Anteroposterior. (B) Lateral.