Scapular winging in athletes: a rare clinical entity

Scapular winging (SW) is extremely rare clinical entity. It is defined as protrusion of the scapula from the thoracic wall. Here, we report a 21 year-old handball player presented with pain in the right shoulder with weakness and discomfort during playing handball for three months. Clinical examination revealed medial scapular winging. Electromyography found neurapraxic of the long thoracic nerve. Hence, the diagnosis of the SW due to serratus anterior palsy was retained. The patient was treated with rehabilitation and physiotherapy for range of motion of the right shoulder. At 14 month follow-up, the patient was asymptomatic and was returned to sport activities.


Introduction
Scapular winging (SW) is one of rare abnormalities of the scapulothoracic joint. It is described as protrusion of the scapula from the thoracic wall [1]. This special condition could be a source of disability and considerable functional impairment that affect the performance of daily activities of upper limbs [1,2]. SW could be due to a number of pathologies which affect the scapular muscles that stabilize the scapula against the thoracic wall [3]. The authors report an unusual case report of SW and review of literature, in order to describe etiology, diagnosis and treatment of this rare entity.

Patient and observation
A 21 year-old handball player presented with pain in the right shoulder for three months. Then, the pain is replaced by shoulder weakness and discomfort during playing handball.
Moreover, he complained of reduced sports performance.
However, there was no history of evident direct trauma.
Clinical examination revealed medial scapular winging ( Figure   1, Figure 2) that was exacerbated with forward flexion of his right arm ( Figure 3). In addition, the medial border of the scapula lifts off the thoracic wall and the right scapula translates medially and superiorly. Scapula stabilization test against the thorax was positive and was relieved the discomfort that improve the shoulder flexion. Full passive and active range of motion in the right shoulder was normal. The neurological examination was uneventful. Radiographs of the right shoulder and scapula were normal. However, electromyography found neurapraxic of the long thoracic nerve. Hence, the diagnosis of the SW due to serratus anterior palsy was retained. After discussion of therapeutic modalities, the patient opted for conservative treatment. The rehabilitation protocol included physiotherapy for range of motion of the right shoulder, scapular stabilization exercises.
At 14-month follow-up, the patient was asymptomatic and was returned to sport activities.

Discussion
Since the first description of the SW by Velpeau in 1837, this term used to define abnormal protrusion of the scapula from the thoracic wall that can lead to pain, discomfort and functional limitation in the upper limbs. SW is extremely rare.
Moreover, the incidence of serratus anterior palsy has been estimated at 0.21% [4]. Overpeck et al. [5] reported only one case of this injury in 38,500 patients observed. Whereas recent reports have suggested that the incidence is difficult to assess, because this pathology is frequently misdiagnosed. SW is often the result a failure in the dynamic stabilization of the scapula against thorax that leads to a prominence of the scapula. These supporting structures are essentially consisted of three muscles: serratus anterior, trapezius and rhomboids major and minor [6]. It has been reported that serratus anterior palsy due to lesion of the long thoracic nerve remains the most common cause of the SW as seen in our case [1,7]. This nerve injury can be caused by iatrogenic, traumatic and idiopathic processes. The traumatic paralysis of serratus anterior can also be due to repetitive movements, especially in athletics [1].
Rarely, the cause of the SW is direct traumatic injury such as muscular avulsions [8]. Clinically, the characteristic symptom is pain in the shoulder. Typically, the patient complained shoulder weakness and discomfort. In addition, the athletes can complain of reduced sport performance [1,7]. Generally, the diagnosis of SW is easily made with a careful physical Most reports concerning treatment of the SW demonstrated that depends the etiology of winging [7]. Indeed, prompt surgical management is indicated in acute muscular avulsion [7,8], while conservative treatment is indicated in nerve injuries. These latter are the most usual cause of SW.
Serratus anterior palsy resolves spontaneously within 1-24 months. Hence, conservative treatment should be accomplished for 6-24 months in these cases [1,7]. However, the patients who fail conservative treatment, surgical management is recommended. Various surgical treatment

Competing interests
The authors declare no competing interests.

Authors' contributions
All the authors have read and agreed to the final manuscript.