Distal Clavicle Osteolysis


Distal clavicle osteolysis also called weight lifter’s shoulder affects the acromioclavicular joint (AC joint). It is a rare condition that usually affects weight lifters and athletes who perform repetitive overhead motions. Although this condition is prevalent in men but with the rise of bodybuilding and extreme athletics it has also started affecting women. 


Osteolysis can also impact people who lift heavy objects frequently like construction or factory workers or people who repeatedly have to exert force on the shoulder like tennis or squash players or competitive swimmers. Distal clavicle osteolysis is a painful condition that affects the regular functioning of the shoulder reducing mobility.


What is Distal Clavicle Osteolysis?

Osteolysis refers to the loss of calcium in the bones which leads to softening or dissolution of the bone. In distal clavicle osteolysis, the ending of the clavicle slowly begins to break down and dissolve.


The AC joint is the junction where the acromion- a part of the scapula (shoulder blade) meets the clavicle (collarbone) at its distal (outer) end. They are connected by the acromioclavicular ligament which enables the arm to perform overhead motions like weightlifting. In some people, due to various factors, the distal end of the clavicle at the AC joint begins to lose calcium causing it to soften and erode. 


What causes Distal Clavicle Osteolysis?

As it is a very uncommon condition the specific cause of distal clavicle osteolysis is not completely understood. However, it is thought to be caused by a combination of factors such as:

  • Repetitive microfractures to the AC joint or distal clavicle
  • Repetitive overhead motions performed with heavyweights (thus the name weightlifter’s shoulder)
  • A combination of long-term wear and tear of the joint combined with an already existing condition such as rheumatoid arthritis
  • Although rare a single blunt force injury to the clavicle such as a fall or a physical blow could also be a probable cause

It is found that among weight lifters, certain activities overload the joint causing microtrauma. The damage does not have the time to heal between sessions and when this goes on for a long time, the bone begins to dissolve instead of healing. 


Symptoms of Distal Clavicle Osteolysis


Distal clavicle osteolysis starts slowly and worsens over time. Symptoms include:


  • Pain in the AC joint or collarbone while performing overhead motions
  • Tenderness and a dull ache in the affected areas
  • Stiffness in the shoulder that gradually becomes worse with time 
  • Swelling in the area near the shoulder and collarbone


Over time, if the symptoms are not treated the bone may erode up to 3 centimetres.


Diagnosis of Distal Clavicle Osteolysis


Diagnosis of distal clavicle osteolysis begins with the doctor checking the medical history of the patient followed by physical examination. The doctor will perform a cross-body adduction test by pressing the arm laterally across the chest. If there is pain across the chest, the result is considered positive. 


The stability of the AC joint is also tested by holding the distal collarbone between the thumb and forefinger and moving the collarbone in different directions while stabilizing the acromion with the other hand. The shoulder joint should also be tested.


Under expert guidance, the doctor may order an AC injection test. If the patient feels temporary relief after the steroid is injected, then AC joint pain is diagnosed. 


The doctor may also order blood tests if there is a suspicion of potential infection or inflammation in the joint. On X-ray, the area affected with distal clavicle osteolysis will show up as an area of lower bone density or abnormal mineralization of the bone. MRI scans may also be suggested if the doctor suspects there are other problems causing shoulder pain. 


Treatment for Distal Clavicle Osteolysis


Although distal clavicle osteolysis is uncommon, it is treatable. There are numerous conservative treatment methods such as:


  • Rest is necessary and any activities which aggravate the pain further should be avoided.
  • Ice packs provide relief and help in reducing the swelling by a significant amount should be applied at least twice a day
  • Nonsteroid anti-inflammatory medications are essential as they help in relieving the pain and reduce inflammation. Steroid injections can also be prescribed to temporarily ease the pain. 
  • Physical therapy is a great method to restore strength and shoulder to its full function. However, it should only be done when the shoulder has healed and inflammation has stopped. 


It is also suggested that patients who are smokers should quit smoking as it helps with the remineralization process of calcium in the bone. This process may take several months for the bone to completely heal.


If the conservative methods do not yield positive results, the doctor may advise surgery. The surgery involves the removal of the distal end of the collarbone, a technique known as the Mumford procedure. It is a common surgical method used by doctors. Osteolysis surgery can be performed through a small incision or arthroscopically.

People who undergo surgery can resume their normal activities including weight lifting and other sports activities without any loss of function. Recovery can take up to few months and is sped up with physical therapy.