Case report of an unusual extra-articular scapular malunion: Rare indication for surgery

Abstract

Introduction

Scapular fractures are relatively rare injuries usually associated with high-energy trauma and multiple concomitant injuries. Most of scapular fractures do not require surgical intervention.

Patient and clinical history

A 42-year-old male sustained an extra-articular scapular body fracture along with multiple rib fractures with flail segments and right pneumothorax treated with intercostal drain. The scapula fracture was treated non-operatively initially, which resulted in very poor outcome. Operative intervention was planned following scans which showed a bony spike from the ventral surface impinging on the chest wall.

Surgical technique

Bony spur was approached from dorsal side using a three-dimensional anatomical model as a guide for accurate localization.

Results

The patient’s symptoms including shoulder stiffness and pain on deep inspiration settled down completely following removal of the spur.

Discussion

This case presents a new indication for surgical intervention in scapular body fracture which has not been published before. All the relevant measurements related to the fracture namely gleno-polar angle, lateral border offset and angulation were within published limits of indications for conservative treatment. Despite this, it resulted in poor outcome necessitating surgical intervention.

Introduction

Scapula fractures account for 0.5% of all fractures, and while they have traditionally been the result of high-energy trauma with associated multiple concomitant injuries, an increasing number of elderly patients are sustaining these fractures from low-energy trauma. ¹ Fractures of the scapula body or glenoid neck account for 62–98% of all scapula fractures, making extra-articular patterns the most common type.^2–6

Although most do not require surgical intervention, an understanding of the common fracture patterns is of great importance to facilitate timely open reduction and internal fixation strategies for those that do.

Patient and clinical history

We present the case of a 42-year-old left-hand dominant, male HGV driver who fell from his lorry in February 2012, landing on a metal step. He sustained multiple rib fractures with flail segments, a right pneumothorax and an extra-articular right scapula body fracture. His chest injuries were managed with an intercostal chest drain, and the scapula fracture was initially treated non-operatively with sling immobilisation. Subsequent assessment in fracture clinic four months later revealed marked limitation of shoulder movements (active range: 85° Flexion, 60° abduction and 45° external rotation) and exacerbation of pain on deep inspiration, with crepitus noted in the scapulothoracic region on initiation of shoulder abduction. A computerised tomography (CT) (Siemens, Somaton Definition Flash. 0.6 mm slices) scan revealed a comminuted fracture of the scapula body, involving the infraspinous fossa (AO/OTA classification 14B2). In addition to the comminuted fossa fracture, there was a bony spike on the ventral (deep) surface, which was projecting anteriorly from the scapula and impinging on the bony thorax just above the fourth rib (Figure 1). His symptoms appeared to relate to the impinging bony spike, noted on CT.

Figure 1.

Pre-operative 3D CT scans showing the scapula malunion impinging upon the ribs.

Access to the deep surface of the scapula would have entailed significant dissection of peri-scapular muscles with concomitant morbidity, and therefore a less invasive approach was planned.

Surgical technique

A three-dimensional (3D) anatomical model was prepared from the pre-operative CT scans (Materialise mimics software printed on an Objet Eden 3D printer using VeroWhite material) to aid localisation of the bony spur from the dorsal side intra-operatively. This was placed in a sterile transparent bag and sealed to allow examination and measurement intra-operatively.

The patient was placed in a lateral position with his right arm resting on a Carter Braine support. The opposite axilla was padded to protect the brachial plexus. Routine prepping (0.5% alcoholic chlorhexidine gluconate w/v in 70% v/v DEB. Ecolab Ltd, Lotherton Way, Leeds LS25 2JY) and draping of the whole arm, axilla and back was performed, and an Ioban drape was applied to the axilla. The arm was not secured, in order to allow mobilisation during the procedure. An incision over the medial border of the scapula was performed, and the lateral trapezial edge was identified. The trapezius was elevated from the fascia overlying the infraspinatus, and the medial border of the scapula was exposed. Marker sutures were placed to help in restoration of muscular anatomy during closure. The fascial edge of infraspinatus was incised and carefully elevated from the dorsal surface of the scapula enough to expose the base of the bony spike. The suprascapular nerve on the deep surface of the infraspinatus was protected throughout the procedure. The model was checked and the pre-measured distance from the medial border of the scapula, at the level of the scapula spine to the base of the spike was marked. The distance from the scapula spine to the base of the spike, at that distance from the medial border was marked. The area of the base of the spike was thus identified and a burr used to make a triangular shaped osteotomy in the infraspinous fossa. This bone and the attached spike were then removed (Figures 2 and 3). Haemostasis was achieved and the elevated infraspinatus was replaced, the infraspinatus fascia was sutured to the fascia on the medial border of the scapula and the trapezius was sutured back to the fascia over the infraspinatus medial border using the marker sutures as a guide and the wound closed in layers. A pressure dressing was applied over the wound. The arm was mobilised through a range of motion, and the crepitus associated with scapula excursion on the thorax had been abolished.

Figure 2.

Intra-operative images of the approach below the scapular spine, the minimally invasive bony dissection at the base of the malunited bone spike and the removal of spike.

Figure 3.

3D model with removed bone indicating the position of the bony malunion.

Results

Initial recovery was uneventful, and the patient was discharged the following day. Physiotherapy-guided exercises began on the day of surgery and continued over the following weeks. By 36 months, the painful crepitus was still absent, and he had 135° of forward flexion and active abduction, 58° of external rotation and internal rotation to T12 (Figure 4). His constant score at this time was 87 compared to 96 on his non-dominant right side. His Oxford shoulder score was 45 on the affected side compared to 48 on the unaffected side. He had returned to his original employment without restriction and was pleased with the final outcome.

Figure 4.

Clinical images of post-operative range of motion.

Discussion

Most extra-articular fractures of the scapula with minimal displacement can be adequately managed non-operatively.^7–10

Operative indications for scapular fractures are limited and include intra-articular fractures of the glenoid with significant gap and/or step-off,^11–14 glenoid neck fractures with greater than 10–20 mm of medial/lateral displacement (medialisation) and/or 25–40° of angulation,^2,15,16 patients with gleno-polar angle less than 22°^17,18 and symptomatic non-unions. ¹⁹ Symptomatic malunions are uncommon. Cole et al. reported a case series of five patients undergoing operative reconstruction following symptomatic malunion of scapula. ²⁰ The patients’ symptoms from his series included chronic shoulder pain, shoulder weakness, fatiguability and dysfunction resulting in inability to return to work or recreational activity following a period of non-operative management.

In our case, the gleno-polar angle was >22°, lateral border offset was <20 mm and angulation was <40°, all of which are within the published limits of indications for conservative treatment.

Despite the absence of published surgical indications, the patient failed non-operative management due to impingement from the malunion on the thorax with deep inspiration and abduction. This previously un-published indication for operative intervention can be successfully managed with minimal access surgery and pre-operative planning. The use of a 3D model during the operation allows accurate identification of the pathology with limited exposure.

ORCID iD

Bhanu Mishra https://orcid.org/0000-0002-6839-9658