In the case of positive clinical manoeuvres, it is
suitable to recommend another examination for a determination of a diagnosis.
These ones have to find out an eventual damage of labrum glenoidale, or to
eliminate other causes of pains of the glenohumeral articulation, and they also
can prove the instability, i.e. increased motility of the head of the humerus
towards the cotyle.
X-ray picture in classical AP projection
X-ray picture in the classical AP projection does not bring data specifying the diagnosis of the glenohumeral instability. But a modification of this examination exists when a patient with relaxed muscularity of the shoulder weighs down the limb with weights. So an inferior luxation is seen in the X-ray picture, i.e. a shifting of the head of the humerus happens distally.
Axillary X-ray projection
Axillary AP projection can help at the diagnosis of the posterior and anterior subluxation.
Special X-ray projection
Also special projections for a showing of the specific marks of instability exist as Bankart lesion of labrum glenoidale or Hill Sachs defect, which is an impressive fracture of the head of the humerus originating in the place of a compression at luxation by the edge of the glenoid fossa.
With regarding to an existence and accessibility of other methods, the classical X-ray examining techniques are being left, and at a suspicion of the glenohumeral instability following examinations are made:
Arthrography itself, or in combination with DCAT, is a valuable tool in the case of the damage of labrum glenoidale.
Arthroscopy is advantageous for an examination of traumatic changes of labrum glenoidale, moreover a diagnostic part can be simultaneously connected with an arthroscopic operation and a revision of a damaged labrum.
It is obviously the best method for the diagnostics of a damage of labrum glenoidale connected with the glenohumeral instability.
Ultrasound examination of etiology of instability
Unfortunately an ultrasound examination has a small contribution for a proving of the damage of labrum glenoidale. The only exception exists, and it is a damage of labrum glenoidale posterior which is proved by the ultrasound in a form of its abruption, eventually also with the edge of the fossa. But it is not easy to examine the anterior labrum. During the ultrasound examination we can prove Hill Sachs defect very well because the articular surface is more exactly examined by the ultrasound than by radiological examination.
Ultrasound proving of the instability
Ultrasound instability also proves an eventual instability comparing the distances of articular surfaces of the scapula and the head of the humerus
- in resting position
- in strained position
The ultrasound examination of the instability is made at various levels in the dependence on the type of the instability. According to Sattler it is necessary to take as pathological side differentiation of 4 mm at total shift bigger than 5-8 mm. But some authors highlight a certain side physiological divergence between the dominant limb, and the limb which is not dominant. We reach the strained position either directly by a pressure of an explorer or mostly by a traction of the examined limb in a suitable direction. We examine subluxations and luxations in basic sections by side comparison of osseous structures.