Scapula fractures Flashcards
What is the origin of the biceps brachii muscle?
The supraglenoid tuberosity
What is the origin of the acromial head of the deltoideus muscle?
Acromium
What nerves are closely associated with the scapula?
Suprascapular (wraps distally around the scapular spine deep the acromium), axillary (caudal scapulohumeral joint)
How is a standard craniocaudal view of the scapular taken?
What occurs with damage to the suprascapular nerve?
Infraspinatous and supraspinatous atrophy
What are the classification systems used for scapular fracture?
Traditional:
1 - body and spine
2 - neck
3 - glenoid
Cook et al:
1. Extraarticular stable
2. Extraarticular unstable
3. Intraarticular
Which scapular fractures should be repaired?
Extraarticular unstable and intraarticular
What are common extraarticular unstable fractures of the scapula?
Scapula neck, acromium, unstable overriding body fractures
Where is bone depth greatest in the scapula spine?
Cranially it is deepest distally, and caudally it is deepest proximally.
Therefore proximal fractures should be plated caudally and distal fractures should be plated cranially.
How can scapula body fractures be repaired?
Interfragmentary wire (with Velpeau sling), plating (inverse tubular plate can be useful, locking implants theoretically may be useful). If implant failure occurs partial or total scapulectomy is an option.
Conservative management can be considered for stable fractures (Velpeau sling).
How can acromial fractures be repaired?
K-wires and figure of 8, interfragmentary wiring
How are scapular neck fractures approached?
Osteotomy of the acromium process or by tenotomy of the tendon of origin of the acromial head of the deltoideus. Muscle separation approach has been described.
What nerves must be protected during approach to the scapula neck?
Suprascapular and axillary.
How can scapula neck fractures be repaired?
Cross-pinning (normal or divergent), plating.
Bandaging with a Velpeau sling for 2 weeks recommended following repair.
Is avulsion fracture of the supraglenoid tuberosity considered an intra-articular fracture?
Yes.
Normally occurs in young dogs (fusion occurs at around 5 months of age).
What is the surgical approach to fractures of the supraglenoid tuberosity?
Osteotomy of the greater tubercle, longitudinal myotomy of the supraspinatous muscle.
How can supraglenoid tuberosity fractures be repaired?
Lag screw with anti-rotational K-wire, k-wires and figure of eight, fragment excision and tenodesis of the origin of the biceps.
What are the two most common types of glenoid fractures?
Cranial glenoid (including supraglenoid tuberosity) or T-Y fractures.
What is the surgical approach to repair of glenoid fractures?
Osteotomy of the greater tubercle, acromium +/- tenotomy of the tendon of insertion of the infraspinatous or teres minor muscles.
How can glenoid fractures be repaired?
Glenoid T-Y: Lag screw should be placed cranial-caudal to stabilize articular component, followed by plating of the neck.
Glenoid excision or arthrodesis can be considered for non-reconstructable comminuted fractures.
How are fractures of the medial or lateral labrum of the glenoid repaired?
Lateral to medial lag-screw fixation if fragment is large enough.
What causes avulsion of the scapula from the body wall?
Rupture of the serratus ventralis muscle.
How can scapula luxation be repaired?
Wiring of the caudal border of the scapula to the 5th, 6th, or 7th rib. Augmentation with Velpeau sling. Prognosis is excellent.
Can ununited accessory ossification center of the caudal glenoid result in lameness?
Yes, has been reported if unstable. Typically resolves with removal.
In a study by Kulendra 2019 in VCOT, what methods of repair were reported for supraglenoid tubercle fractures? What factor was associated with a higher rate of complications?
Pin and TBW, lag screw, plate fixation, fragment removal, and conservative management.
Comminution was associated with an increased risk of complications.
What are the two ways that fractures of the supraglenoid tubercle can be approached?
Either via osteotomy of the greater tubercle of the humerus or by splitting the supraspintous muscle. Splitting of the muscle may be preferred in juvenile patients to avoid growth plate disruption.
