Frequently Asked Questions
Joint Dislocations
A dislocation is diagnosed when two bones that form a joint shift away from each other. One bone in a ball and socket type joint can “pop out of joint” usually due to an external force. The level of force required to sustain such an injury is usually significant enough to cause a fracture.
The amount of soft tissue damage to the supporting structures around a joint varies with every injury and how many times it has happened in the past. Dislocations can occur once only, but can also be recurring due to the soft tissues around the joint becoming stretched during previous dislocations.
A subluxation describes a bone moving part way out of place then moving back in again.
A dislocated shoulder occurs when the ball (known as the head) of the shoulder joint (humerus), is forcibly separated from the socket of the shoulder blade (scapula). The ball, which is relatively large, fits into a shallow socket, making the shoulder joint very mobile but very unstable and susceptible to partial dislocation (also referred to as subluxation) and dislocation. A dislocation is a severe joint injury involving tearing of ligaments and other structures around the shoulder. Once the joint is relocated, it is not “fixed” so ongoing treatment and rehabilitation will be needed to repair the soft tissue damage and restore strength and safe flexibility.
As many as 90% of athletes under the age of 40 repeatedly dislocate their shoulder. This is because of the position of the shoulder during overhead activities such as swimming and throwing. Sometimes the axillary nerve may be damaged during the dislocation which can cause temporary weakness to the deltoid muscle making it difficult to lift the arm.
There are three types of shoulder dislocations, but in 95% of cases the shoulder moves in front of the body which is known as an anterior dislocation. These usually occur in younger individuals. Anterior shoulder dislocations are often caused by a direct blow to the shoulder or by a fall onto an outstretched hand.
Posterior dislocations, where the head of the humerus is displaced backwards, are much less common and as a consequence can initially go undiagnosed.
People who have suffered a stroke can have weakened shoulder muscles that result in a gradual dropping of the humerus out of the socket, leading to a downward pull (inferior subluxation) of the head of the humerus under the force of gravity. These shoulder subluxations can be a great source of pain.
In the case of a finger dislocation, one bone shifts off the saddle-type seat it normally sits on. A joint may dislocate and immediately “go back in” or it can remain out of place in which case the finger will look misshapen or shortened.
This injury commonly occurs when the finger is either bent too far back or bent forwards with significant force, and is more common in those with flexible joints. A strong ligament of the finger (the volar plate) and possibly other ligaments around the joint are torn allowing the bone to shift out of position.
If your finger is fully dislocated it will be quite painful, appear short or misshapen and you will feel that you have to put it back in place. In the case of subluxation, it will return to its normal position on its own. Your finger may be swollen and tender when it is pushed straight, but it may also feel weak and you may have difficulty performing certain tasks.
Dislocated fingers are usually sore and swollen for days, weeks and months afterwards, depending on the level of injury and the treatment applied. In the longer term a dislocated finger can result in either a stiff finger with reduced movement or a loose joint that is prone to further injury and a feeling of giving way. An X-ray is advisable as it is possible to mistake a dislocation for a fracture and vice versa as the symptoms are similar.
A volar plate injury, a moderate ligament injury or a fracture needs to be supported by a splint to assist healing. The position of the splint will be determined by what has been injured. A dislocation will often need to be held in a bent position to make sure stability of the joint is restored, but a fracture will often be splinted with the finger straight.
Your physio will prescribe exercises at the appropriate time, assessing how much support and exercise is optimal for healing and function. Your finger will then be stretched and strengthened to restore normal movement and function.
