INDICATIONS IN FRACTURES OF THE ANTERIOR GLENOID RIM
Department of Orthopaedic Surgery, Clinique Sainte Anne Lumière Lyon
Anterior instability is frequently associated with bony Bankart lesion which is an osseous lesion of the glenoid. Three types of osseous lesion may be identified :
• "Fracture" defined as an abnormality of the anterior glenoid rim characterized by a visible osseous fracture fragment.
• The "Cliff sign" defined as a loss of the normal anterior triangle without a visible osseous fracture fragment.
• The "Blunted angle sign" is defined as a rounding off of the normally sharp anterior angle of the triangle.
The purpose of this paper is to discuss our indications in case of anterior instability (acute and chronic) with a fracture of the glenoid rim.
I – Acute anterior instability
After a traumatic anterior dislocation or subluxation, a fracture of the anterior rim may be detected with standard AP view or with a Garth incidence. The size of the fracture varies from 1 mm to 15 mm. We propose a systematic surgical anterior approach to fix the fragment with screw in cases of incoercible dislocation or in case of static persistent anterior subluxation of the humeral head.
• Incoercible dislocation : when after many attempts of reduction, the dislocation invariably recurs even with the protection of the sling, the problem is often a large fracture of the anterior glenoid rim. We fix it with one or two AO cortical screw 3.5 mm diameter, through a subscapularis horizontal split.
• Static persistent anterior subluxation : after an anterior dislocation with large fracture of the antero-inferior glenoid rim mainly in the older people ; on the control x-rays there is a slight antero-inferior displacement of the humeral head with superposition of the head and the glenoid. This is better analysed on x-rays than on CT scan. If this malposition persists despite a different type or different position of immobilisation, there is a necessity for ORIF of the fracture of the glenoid rim.
Beside these two special circumstances, we also recommend ORIF in the young athletes when the risk of recurrent instability may compromise their career. Otherwise we treat conservatively the patient with a sling for three weeks followed by a progressive gentle rehabilitation program. It takes usually three to six months to observe a good bone healing of large fractures.
Small fractures may never healed and lead to recurrent anterior instability.
II – Chronic anterior instability
Fracture of the anterior glenoid rim may be associated with recurrent dislocations, subluxations or with chronically painful shoulder (at least six months duration) in abduction external rotation without a defined history of dislocation or subluxations.
We treat these patients with a Latarjet procedure even in the case of advanced arthritis which is not rare in these circumstances.
Rarely the fracture is too big (more than one third of the antero-posterior diameter of the glenoid) and the coracoid process is to small to stabilize the joint. In these cases we perform a reconstruction of the anterior inferior glenoid with an iliac crest graft. To keep "the hamac effect" of the inferior third of the subscapularis muscle, the reconstruction is performed through a split of the subscapularis and the coracoïd process is attached either above or anterior to the iliac crest graft. The conjoined tendon maintains the inferior part of the subscapularis at the inferior part of the glenoid whatever the position of the arm (abduction external-rotation).