Major Joint dislocations by Dr Prassan Tripathi

Medical education

1. DISLOCATION OF MAJOR JOINTS Dr PRASSAN TRIPATHI Asst. P. ORTHOPEDICS RSDKS GMC AMBIKAPUR

2. Definition Dislocation: A joint is dislocated when its articular surfaces are completely displaced, one from the other, so that all contact between them is lost Subluxation: A joint is subluxated when its articular surfaces are only partly displaced and retain some contact between them.

3. RELEVANT ANATOMY F actors responsible for the stability of a joint. Normally, a joint is held in position because of the inherent stability in its design, by the ligaments, and by the surrounding muscles. The shape of a joint: The shape of the articulating surfaces in themselves may provide great security against displacement, e.g., the hip joint with its deep socket (the acetabulum) and an almost spherical ball (the femoral head) is a good design from the stability viewpoint. On the other hand, the shoulder joint with its shallow socket (the glenoid) and a large ball (the humeral head) is a poor design and therefore dislocates more easily than the hip joint.

4. Stablizers The ligaments: These prevent any abnormal mobility of a joint and are called static stabilisers . The role of the ligaments in providing stability to a joint is variable. In some joints (e.g., the knee and finger joints), ligaments form the main stabilizing structures, whereas in others (e.g., the hip or shoulder) they do not play an important role. The muscles: A strong muscle cover around a joint gives it stability. Muscles may also provide a supporting function to the ligaments by reflexly contracting to protect the ligaments, when the latter come under harmful stresses. These are, therefore, called the dynamic stabilisers of a joint.

5. Classification Dislocations and subluxations may be classified on the basis of aetiology into congenital or acquired. 1. Congenital dislocation is a condition where a joint is dislocated at birth e.g., congenital dislocation of the hip (CDH), congenital dislocation of knee. 2. Acquired dislocation may occur at any age. It may be: T raumatic P athological

6. Traumatic dislocation Injury is by far the commonest cause of dislocations and sub- luxations at almost all joints. The following are the different types of traumatic dislocations seen in clinical practice: a) Acute traumatic dislocation b) Old unreduced dislocation: A traumatic dislocation, not reduced, may present as an old unreduced dislocation. c) Recurrent dislocation: Recurrent dislocation of the shoulder and patella are common. d) Fracture-dislocation: When a dislocation is associated with a fracture of one or both of the articulating bones, it is called fracture dislocation.

7. Pathological dislocation The articulating surfaces forming a joint may be destroyed by an infective or a neoplastic process, or the ligaments may be damaged due to some disease. This results in dislocation or subluxation of the joint without any trauma e.g., dislocation of the hip in septic arthritis.

8. Reduction Technique 1. Kochers method 2. Hippocrates method 3. Milch’s Method 4. Stimson’s Technique

9. Posterior dislocation is the commonest type of elbow dislocation. Other dislocations are posteromedial, postero -lateral, and divergent*. It may be associated with fracture of the medial epicondyle, fracture of the head of the radius, or fracture of the coronoid process of the ulna. Clinically, there is severe pain at the elbow. The triceps tendon stands prominent (bowstringing of triceps). The three bony points relationship is reversed. There is often an associated median nerve palsy. Diagnosis is easily confirmed on X-rays (Fig- 14.19). Treatment: It is by reduction under anaesthesia followed by immobilisation in an above- elbowplaster slab for 3 weeks. Elbow stiffness and myositis are common complications.

10. PULLED ELBOW This condition occurs in children between 2-5 years of age. The head of the radius is pulled partly out of the annular ligament when a child is lifted by the wrist. The child starts crying and is unable to move the affected limb. The forearm lies in an attitude of pronation. There may be mild swelling at the elbow. It is not possible to see the subluxated head on an X-ray because it is still cartilaginous; X-rays are taken only to rule out any other bony injury. Treatment: The head is reduced by fully supinating the forearm and applying direct pressure over the head of the radius. A sudden click is heard or felt as the head goes back to its place. The child becomes comfortable and starts moving his elbow almost immediately.

11. Classification There are three main types of dislocations of the hip: ( i ) Posterior dislocation (the commonest ) (ii) Anterior dislocation (iii) Central fracture dislocation. All of these may be associated with fracture of the lip of the acetabulum.

12. Reduction Technique Allis Maneuver Bieglow Maneuver Stimson gravity Technique East Baltimore Technique