Scapular osteochondroma: An unusual cause of static winged scapula in a pre-teen

Okechukwu Onwuasoigwe; Augustine C Onuh; Arinze D G Nwosu

doi:10.4103/ijmh.IJMH_29_21

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CASE REPORT

Year : 2022 | Volume : 27 | Issue : 2 | Page : 204-207

Scapular osteochondroma: An unusual cause of static winged scapula in a pre-teen

Okechukwu Onwuasoigwe¹, Augustine C Onuh², Arinze D G Nwosu³
¹ Department of Orthopaedic Surgery, University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State, Nigeria
² Department of Radiology, University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State, Nigeria
³ Department of Anaesthesia, National Orthopaedic Hospital, Enugu State, Nigeria

Date of Submission	26-Jun-2021
Date of Decision	13-Sep-2021
Date of Acceptance	10-Nov-2021
Date of Web Publication	3-Mar-2022

Correspondence Address:
Okechukwu Onwuasoigwe
Department of Orthopaedic Surgery, University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State.
Nigeria

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijmh.IJMH_29_21

Abstract

Winged scapula is most commonly caused by injury of the long thoracic nerve which results in paralysis of the serratus anterior muscle. Scapular osteochondroma is uncommon and rarely presents as winged scapula in the skeletally matured patients. We report a 9-year-old female with progressive winging of the left scapula due to osteochondroma on its costal surface. The clinical diagnosis of the cause of the scapular winging was difficult because the tumor was non-palpable, mainly cartilaginous, and not visible on a plain radiograph but was unraveled with ultrasonography. Diagnosis of osteochondroma in a pre-teen is unusual but should be considered in the differential diagnosis for static-winged scapula in a child.

Keywords: Differential diagnosis, pre-teen, scapula osteochondroma, static winged scapula, ultrasonography

How to cite this article:
Onwuasoigwe O, Onuh AC, Nwosu AD. Scapular osteochondroma: An unusual cause of static winged scapula in a pre-teen. Int J Med Health Dev 2022;27:204-7

How to cite this URL:
Onwuasoigwe O, Onuh AC, Nwosu AD. Scapular osteochondroma: An unusual cause of static winged scapula in a pre-teen. Int J Med Health Dev [serial online] 2022 [cited 2022 May 24];27:204-7. Available from: https://www.ijmhdev.com/text.asp?2022/27/2/204/339031

Introduction

Winged scapula is an abnormal scapulothoracic posture and motion characterized by protraction of the medial border of the scapula from the chest wall. It is a rare disorder which can impair the functions of the affected upper extremity.^[1],[2] Winged scapula is commonly caused by neuromuscular imbalance in the scapulothoracic stabilizer muscles. Injuries of the long thoracic nerve or the spinal accessory nerve resulting in paralysis of the serratus anterior or the trapezius muscle, respectively, are commonly implicated.^[3],[4],[5] Occasional cases resulting from rhomboid muscle paralysis have been mentioned. However, deformities mimicking winged scapula from other bone and joint pathologies or rotator cuff dysfunction around the shoulder have been described.^[3]

Osteochondroma is the most common benign bone tumor^[6],[7] and represents about 15% of all primary bone tumors.^[7] It could be solitary or multiple and commonly presents from the second decade of life. Solitary osteochondroma predominates and accounts for about 90% of the cases. The osteochondroma commonly presents as osteocartilaginous exostosis at the metaphysis of a long bone, especially the distal femur, proximal tibia, and proximal humerus.^{[6],[7],[8],[9]} Cases of multiple osteochondromas, also called hereditary multiple exostoses or diaphyseal aclasias, are rarer.^[6]

The scapula is an uncommon site for osteochondroma. However, scapular osteochondroma resulting in winged scapula has been rarely reported in the skeletally matured patients.^[10],[11] When this occurs in a pre-teen, it can pose a diagnostic challenge to the clinician because the mass on the costal surface of the scapula is concealed and not accessible to palpation. We report a case of winged scapula from osteochondroma in a 9-year-old girl and discuss the diagnostic difficulties.

Case Report

A 9-year-old female presented to our outpatient clinic with a 1-year history of progressive winging of the left scapula. She had gritty pain on abduction of the left shoulder. There was no history of trauma or surgery and no significant family history. The birth history and the patient’s development were normal. She did not admit any functional limitation of the left upper extremity.

The clinical examination showed a healthy girl with static winging of the left scapula [Figure 1]. The range of movement of the shoulder was normal except with abduction which was actively done with some difficulty from about 100°. There was no muscle paralysis or sensory loss around the shoulder, and the scapula palpation for a mass was unrewarding. Plain anteroposterior and lateral and axillary radiographic views of the scapula were similarly unrewarding, and the patient did not afford the financial cost of the prescribed CT scan of the scapula. However, with ultrasound scan of the left shoulder region, a cartilaginous exostosis on the costal surface of the left scapula was reported [Figure 2]. The hematologic and biochemical studies on the patient showed normal results.

Figure 1: Clinical demonstration of the left static winged scapula

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Figure 2: Ultrasound image of osteochondroma

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After counsel of the parents, the patient had an uneventful surgical excision of the scapular mass-confirmed osteochondroma at surgery [Figure 3]A and B and with histopathology examination. She has been followed up for more than 2 years, and the scapular winging has remained resolved [Figure 4].

Figure 3: A: Demonstrating the pedunculated osteochondroma intra-operative. B: The excised osteochondroma

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Figure 4: The surgically corrected left winged scapula

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Discussion

The deformity of winged scapula is classified as either static or dynamic. In the case of static winged scapula, the protraction of the medial border of the scapula is obvious on inspection with the shoulder at rest. It remains fixed and not accentuated by movements of the shoulder. In contrast, dynamic winged scapula is often not noticed with the shoulder at rest but becomes manifest during active or resisted movements of the shoulder. This important clinical distinction quickly separates dynamic scapular wingers, which are invariably the result of neuromuscular imbalances, from the static scapular wingers. The deformity in the reported patient clinically demonstrated static winged scapula.

The two commonly encountered etiopathologies for the dynamic winged scapula relate to serratus anterior muscle weakness due to long thoracic nerve palsy or trapezius muscle paralysis from spinal accessory nerve injury.^{[1],[2],[3],[4],[5]} The clinical inclination—either medially or laterally—of the prominent medial border of the dynamic winged scapula [Figure 5]A and B^[5] further points to the likely neuromuscular cause, the static winged scapula often requires painstaking clinical examination and investigations to decipher from the myriad of possible causes.

Figure 5: A: Dynamic right winged scapula due to serratus anterior muscle weakness with medial inclination of the medial border of the scapula. B: Dynamic left winged scapula due to trapezius muscle paralysis with lateral inclination of the medial scapula border

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Scapular osteochondroma has rarely been reported as a cause of winged scapula in skeletally matured patients.^{[8],[10],[11],[12],[13]} Fiddian and King^[10] reported one case of scapular osteochondroma out of 209 patients with winged scapula, an incidence of 0.48%. The authors located the exostosis at the costal surface of the scapula with radiography and explained the pathogenesis of the static winging by its mass effect.

Our patient had a 1.5 cm × 2 cm pedunculated exostosis on the costal surface of the scapula, which presented classically as static winged scapula. The scapular mass was not palpable due to its location and that made clinical diagnosis difficult. The typical presentations of hereditary multiple exostoses which include skeletal deformities and short stature were not seen in our patient. Patients with osteochondroma most commonly present from the second decade of life, but our patient was younger. There is a positive family history in more than about 50% of patients with hereditary multiple exostoses.^[6] This was however not present in our patient.

The pattern of presentation of our patient could pose a diagnostic challenge to the clinician, particularly in the absence of the common causes of scapular winging and a non-palpably accessible scapular mass. A high index of suspicion is therefore necessary to make the diagnosis. Plain radiography is the main diagnostic modality for osteochondromas^[10],[14] because the osseous part of osteochondroma is radio-opaque. Anteroposterior and lateral views are usually sufficient to characterize the lesions. Radiographs, however, did not help in our case probably because the mass was mainly cartilaginous. In certain locations such as scapula and pelvis, a CT scan is useful to localize and characterize the lesion when planning surgical excision. The parents of the patient were peasant farmers and could not afford the cost of the prescribed CT scan. However, this limitation of not getting a CT scan led us to try the use of ultrasound scan with good result. Ultrasonography was cheaper and more readily available than CT scan in our region and could localize the scapular lesion. This was made possible because the mass in the younger child was mainly cartilaginous. We therefore recommend ultrasonography as an option in the investigation of static winged scapula, particularly in children.

The treatment of choice of symptomatic exostosis is complete surgical excision.^{[6],[8],[10],[11],[12]} The index patient had a successful excision of the mass through a longitudinal incision that skates the medial border of the scapula. There was dramatic resolution of the winged scapula and complete recovery of the shoulder abduction post-operatively. The patient has been followed up for more than 2 years without recurrence of the lesion.

Conclusion

Scapula osteochondroma should be considered a differential diagnosis of static winged scapula even in a pre-teen patient. A high index of suspicion is recommended. Ultrasonography can enhance diagnosis of scapular osteochondroma in a child when plain radiography may not help and especially in resource-poor regions where CT scan and MRI are often out of reach in terms of cost and availability.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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