Dislocations

dislocation

What is it?

A dislocation is separation of the two sides of joint surfaces are out of contact. Shoulder is the most common location for dislocation, it also occurs in fingers, elbow, knees and hips.

Cause

High impact injury is the usual cause of dislocations in most of the joints in the body as in case of a fall or a blow from playing contact sport. However, after the first time some of the joints could dislocate with trivial incidents as seen in case of recurrent (habitual) shoulder dislocation.

Symptoms

During the first-time occurrence, the affected joint will result in intense pain and deformity. It will also be difficult to move the joint around and use it. When dislocations occur multiple times in a joint, it can be less painful with primary complaint being deformity and inability to use the joint.

Diagnosis

It is usually obvious to pick when a joint is not located. After we perform relevant history and examination, we conduction imaging.

X-ray: usually shows the dislocation. Different angle views might be needed in some dislocations.

A computerized tomography (CT) scan might be necessary to better understand the nature of the dislocation and assess if there is associated fractures (as seen in complex dislocations) that could be missed with x-ray alone.

Magnetic Resonance Imaging (MRI) may be needed to assess the degree of the soft tissue damage in and around selected dislocated joints. I also request for MRI in hip joint dislocations that present to me late after weeks of dislocation, to help me assess the viability of the femoral head, to help me decide if I could salvage the natural hip joint or do hip replacement. The futured x-ray above shows a young man’s x-ray that presented to me 6months after the hip dislocation. His MRI showed viable femoral head with no sign of avascular necrosis of femoral head. I was then able to successfully do hip relocation to preserve his natural joint.

Treatment

Joint dislocations are one of the orthopedic injuries that need an emergency intervention. Joint covering cartilage surface does not have its own direct blood supply. It gets nurition from the fluid in the joint by a process called diffusion. The blood supply to selected bony parts of the joint (e.g. the femoral head) is also often disruption when it dislocates. Hence, timely reduction within hours of dislocation is one of a key intervention to keep cartilage surface nurished and restore the blood supply to the bony parts of the articulating bones.

Timely reduction can usually be successfully conducted by a non-surgical means with appropriate pain control and muscle relaxation.

Surgical might be needed in:

  • Irreducible joints
  • When dislocations are associated with fractures that require fixation.
  • Late presenting dislocation as in the depicted example above where the joint surfaces will be filled with scar tissue hindering reduction.
  • To prevent or treat recurrent dislocations.
  • Treatment of late complications like avascular necrosis or arthritis.

Dr Sami’s special focus of  interest is in hip and elbow joint dislocations. He has published his work with his colleagues on special technique for late presenting elbow dislocations. This work was awarded as the best international paper of 2015 Orthopedic trauma association in the USA.

His late presenting hip dislocation research work is in progress that showed a remarkable result in selected patient groups. Dr Sami also performs total hip replacements for hip dislocations that resulted in AVN, arthritis and in selected cases of acute dislocations when associated with complex injury that is not amenable to hip preservation.

Compiled and written on June, 2021. By Dr. Samuel Hailu.

*Disclaimer:*The information contained herein is for educational purposes only. This should NOT be used in place of a visit with your healthcare provider, nor should you disregard the advice of your healthcare provider because of any information you read on this topic.