| This condition is moderately common, occurs typically | | | | * I refers to the technical types of surgery and where |
| on both sides and is a non-traumatic condition which | | | | they are performed. |
| interferes with the function of the shoulder. The laxity | | | | The shoulder joint exhibits a high level of joint mobility |
| of the shoulder capsule and thereby the lack of its | | | | to allow it to participate in placing the hand in many |
| inherent ligamentous restrictions is the underlying | | | | potential places in space, in front of the eyes so we |
| problem causing these difficulties. With this laxity there | | | | can see what we are doing. This mobility is at the cost |
| is an excess of mobility in the shoulder joints in every | | | | of stability, so the shoulder fails to be sufficiently stable |
| joint direction. Patients may complain of instability, with | | | | under certain conditions. |
| the feelings that the shoulder will partly or wholly come | | | | Thinking about the stability of the shoulder it is helpful to |
| out of joint at times. If this instability is not obvious to | | | | concentrate on a few concepts. The idea of balance |
| the patient they may complain only of pain when they | | | | is related to the way the head of the humerus centres |
| present. | | | | itself on the socket accurately. The main muscles |
| Conservative treatment is the first line of management | | | | responsible for maintaining this anatomical alignment |
| for this condition, with physiotherapy treatment | | | | are those of the rotator cuff, keeping the joint in line as |
| consisting of strengthening of the muscular parts of | | | | the larger movement muscles do their actions. If an |
| the scapular stability and rotator cuff systems. Once | | | | imbalance or weakness develops in the muscles of |
| conservative treatment has been attempted and not | | | | the scapula or the rotator cuff then the balance can |
| been successful then consideration can be given to | | | | be disturbed. A cartilage rim around the socket, the |
| surgery. Surgery can tighten up the shoulder capsule, | | | | glenoid labrum, deepens the socket and the muscles |
| increasing the strength of the static stabilisers. Typically | | | | compress the two parts together, enhancing stability. |
| surgery has been done in open technique but | | | | An upward movement of the humeral head on the |
| arthroscopic technique is become more prevalent. | | | | socket is undesirable and this tendency is resisted by |
| How common this pathology is in the overall population | | | | the compressive force of the rotator cuff and by the |
| is not clear and it is much more common to have | | | | curve of the upper socket area. The joint surfaces |
| instability of the shoulder from traumatic events such | | | | have some adhesion as they are wetted by the |
| as incidents which lead to shoulder dislocation. In this | | | | synovial fluid, with air being pressed out of the joint by |
| field there are several different classifications, TUBS | | | | the tight fit of the rounded ball and the depth of the |
| stands for: | | | | socket, creating a degree of suction effect to enhance |
| * Trauma involved in the cause | | | | stability. Some amount of negative pressure which |
| * Unidirectional instability - only in a single direction | | | | develops in a tight joint also adds to the effect. The |
| * Bankart lesion (damage to the rim around the | | | | stability which is improved by these effects is in the |
| shoulder socket) | | | | mid-range of the joint's movement, where there is |
| * Surgery - is a common requirement | | | | least stability from the ligaments. |
| A single or repetitive dislocation of a shoulder joint | | | | The joint capsule acts passively to hold back |
| traumatically can lead to the generalised instability | | | | excessive movement of the shoulder and keep it |
| problem described in TUBS. | | | | within safe limits, with thickened areas of the capsule |
| The instability type which is multidirectional is given the | | | | developed into the ligaments of the shoulder, the most |
| acronym AMBRI which stands for: | | | | important of which is the inferior glenohumeral ligament. |
| * Atraumatic - there was no accident or injury to | | | | This does not mean that the muscles, the dynamic |
| explain the onset | | | | stabilisers of the shoulder system, are not very |
| * Multidirectional instability - laxness in all joint | | | | important in the normal function of the shoulder. |
| movements | | | | Physiotherapy concentrates on strengthening and |
| * Bilateral - both shoulders are typically affected | | | | re-educating the rotator cuff and scapular stability |
| * Rehabilitation - this is the initial treatment process | | | | muscles. |