What is Distal Clavicular Osteolysis?
Distal clavicular osteolysis (DCO) is an unusual injury that usually strikes athletes and weight lifters, especially those who make repeated overhead movements. When talking about the shoulder, the clavicle, or collar bone, connects with two out of four shoulder joints. One end of the clavicle meets with the breastbone at the sternoclavicular (SC) joint, while the other end joins the acromion process to form the acromioclavicular (AC) joint. This AC joint maintains its stability through the AC joint capsule (AC ligaments) and the coracoclavicular ligaments, as well as the actions of the deltoid and trapezius muscles.
DCO is usually caused by repeatedly putting a lot of stress on the AC joint. This can happen via specific movements of the shoulder, such as moving it horizontally inwards, rotating it internally, and bending it forwards or sideways. These are common motions when doing things like bench pressing or overhead lifting. The theory is that this repeated stress results in small-scale injury to the bone under the cartilage of the distal clavicle, leading to cysts in this bone, disruption of the cartilage, and altered bone formation due to increased activity of bone-dissolving cells.
Taking a break from weight lifting or other activities that led to the injury can help to ease symptoms. There are also some treatments that may help to reduce pain and improve function.
What Causes Distal Clavicular Osteolysis?
Distal clavicular osteolysis, a condition affecting the end of the collarbone, gets often aggravated by certain activities. These include bench pressing, overhead lifting, and a variety of overhead sports like volleyball, basketball, tennis, and swimming.
Such movements put regular strain and pressure on the AC joint, the part of the shoulder where the collarbone joins the highest part of the arm. These repeated minor strains lead to distal clavicular osteolysis. High-intensity bench press, where an individual lifts more than 1.5 times their body weight in single repetition, is one of the most common contributors to this condition.
Risk Factors and Frequency for Distal Clavicular Osteolysis
Distal clavicular osteolysis (DCO), a condition leading to the dissolution of the distal part of the collarbone, largely affects young athletes and weightlifters, especially those involved in highly repetitive pressing or overhead activities. Although it can theoretically occur at any age, it was historically thought to only affect young male athletes and weightlifters. Nowadays, it is also recognized among females taking part in similar strenuous activities.
- DCO usually happens in young athletes and weightlifters.
- It’s often associated with repetitive pressing or overhead activities.
- While initially thought to only affect young males, it is now known to appear in females engaging in similar activities.
- An analysis of 1,432 MRI results of 13 to 19-year-olds with shoulder pain indicates that 6.5% of the cases were identified as DCO.
- Out of these DCO cases, 24% were female.
Signs and Symptoms of Distal Clavicular Osteolysis
People with distal clavicular osteolysis, a condition of the collarbone and shoulder, are usually those who lift weights often, participate in recurrent sports activities that involve extensive overhead movements, or have had an injury to the AC joint, which is where the collarbone meets the shoulder. Sometimes, these individuals do specific gym exercises, like bench pressing, which put extra pressure or stretch on the AC joint and heighten their pain. Stopping these activities can alleviate the pain temporarily, but it comes back when they resume the activities. The pain they feel typically starts gradually and can be described as a dull ache either on one or both sides of the area where the collarbone connects with the shoulder.
Upon a physical exam of a patient with this condition, tenderness will be felt when the area of the AC joint is touched. There might be a little pain when testing their strength, but usually, their strength remains unaffected. Their shoulder movement is mostly normal and without pain, except when bringing their arm up to side (abduction) and rotating it inwards (internal rotation). Tests like the Hawkins and Scarf tests, which load or put weight on the AC joint, will cause pain. To ensure this pain is not coming from somewhere else, doctors will also check the neck and include a neurological exam.
Testing for Distal Clavicular Osteolysis
If you’re being checked for a condition called Distal Clavicular Osteolysis (DCO), a simple x-ray of the AC joint would typically be enough. This kind of x-ray often shows things like tiny cysts, loss of bone detail beneath the cartilage, and degradation of the collarbone’s end.
If the x-ray is unclear or the DCO seems to be in an early or mild stage, your doctor might consider using other types of imaging procedures like an MRI, bone scan, or ultrasound. Using ultrasound to diagnose DCO is a newer tactic. A trained doctor might perform an ultrasound during your check-up. This procedure is significantly cheaper than an MRI or bone scan and might also give a better picture than a standard x-ray.
When deciding which imaging method to use, your doctor will consider other possible problems that might be causing your pain. For example, if your doctor suspects you also have a Superior Labrum Anterior and Posterior (SLAP) tear, they’ll likely use an MRI for a proper evaluation. You typically wouldn’t need any blood or lab tests to diagnose DCO, but based on your symptoms, your doctor might order some to rule out other medical conditions.
Treatment Options for Distal Clavicular Osteolysis
The first line of treatment for a condition called distal clavicular osteolysis usually involves lifestyle changes such as reducing certain activities that might worsen the condition, taking anti-inflammatory drugs, and going through physical therapy. Although there’s no set regimen for physical therapy in these cases, it’s generally recommended to focus on increasing flexibility and strengthening the rotator cuff, which is part of the shoulder.
An important part of treatment for this condition involves injections of a medicine called corticosteroids into the joint. This not only helps reduce pain and improve function, but it can also help doctors make a more accurate diagnosis. If the pain fails to improve after injection, doctors can explore other possible causes of shoulder pain.
Another treatment option that has shown promise in some difficult cases is the use of injections of botulinum toxin – typically associated with Botox treatments. A case study showed one patient with severe pain due to this condition found relief after this treatment.
Currently, there’s no evidence to support the effectiveness of injections of certain substances called orthobiologic injectables, such as platelet-rich plasma, bone marrow aspirate concentrate, or stem cells derived from fat tissue.
If these conservative management strategies fail or the patient is an athlete who can’t modify their activities, surgery can be an effective alternative. The surgical treatment generally involves removing a small portion of the clavicle (collarbone) by an open procedure or through a more minimally invasive technique known as arthroscopy.
The advantage of the open procedure is that it allows direct visualisation of the area and the ability to manage larger bone spurs more effectively, but it might take between 5-12 weeks to recover fully. Arthroscopic procedures involve smaller incisions and may allow patients to get back to their regular activities faster. A study comparing the two arthroscopic techniques found that both gave excellent results, but one method had faster recovery times and better function after surgery.
What else can Distal Clavicular Osteolysis be?
When a doctor is trying to figure out the cause of ongoing pain in the upper part of your shoulder, they will consider a number of possible problems including arthritis in the joint where the collarbone meets the shoulder, inflammation of the fluid-filled cushion under the shoulder blade, tears in specific shoulder tendons, and other physical issues that can cause pain in the shoulder.
It is challenging for doctors to identify exactly what is causing this kind of pain just by using a normal physical examination. Therefore, they generally order imaging tests like x-rays or scans based on which disease or condition they suspect the most. They also remain open to non-physical causes for the pain such as gland disorders (hyperparathyroidism), kidney diseases (gout), connective tissue disorders (scleroderma), joint disorders (rheumatoid arthritis), bone marrow cancer (multiple myeloma), infections, and rare conditions like Gorham’s disease. If the doctor suspects that the pain may be coming from a different area of the body (referred pain), they will perform thorough checks of the neck and the blood vessels and nerves in the area.
Generally, if the patient is young and has been diagnosed with distal clavicular osteolysis, a good physical examination would be enough to rule out many of these conditions. However, if the patient has specific risk factors for a medical illness like a family history of autoimmune disease or additional symptoms, the doctor may also consider conducting lab tests and further imaging studies to pinpoint the correct diagnosis.
What to expect with Distal Clavicular Osteolysis
The outlook for DCO is typically extremely good. In one study based on radiology, it was found that 93% of patients were effectively treated with non-surgical methods.
Currently, there are no specific treatment plans or methods identified in studies, but most include using anti-inflammatory medications, icing after activity, and changing the way you do certain activities. Restrictions might only be temporary, but sometimes it’s only possible to manage the condition in the long term by permanently stopping the activity that’s causing the problem. This might not be practical for athletes, people doing physical work, or soldiers.
Surgery can be effective, and new arthroscopic methods (a procedure using a camera to visualize inside the body) allow people to return to their sports or activities quicker and more successfully.
Possible Complications When Diagnosed with Distal Clavicular Osteolysis
When a patient doesn’t limit movements that cause pain, they can self-inflict what is referred to as a “self-surgery.” This results in the resorption (absorption) of the distal clavicle (the end near the shoulder of the collarbone), which is a clear sign of progressing disease.
A long term study, which used MRI imaging to look at the long lasting effects of DCO (Distal Clavicle Osteolysis – a shoulder condition where the end of the collar bone degenerates), found that common complications included widening of the AC (acromioclavicular) joint and osteoarthritis of the AC joint. However, it’s important to note that, although these were observed on an MRI, not all patients who had these signs actually felt symptoms. The complete impact of these MRI observations is still unknown.
Preventing Distal Clavicular Osteolysis
Similar to other injuries caused by overuse, easing up on certain actions that strain the AC joint can prevent further harm from DCO. This is particularly beneficial for young athletes who regularly perform overhead movements in their sports. They could benefit from other types of training that put less pressure on the AC joint. It’s important to note that heavy bench pressing more than 1.5 times one’s body weight is a risk factor.
The study found that light bench pressing was not a risk factor. However, the chance of getting DCO increases if you bench press over 1.5 times your body weight more than once a week for over five years. These factors contribute to the risk both separately and together.
Besides, refraining from too many push-ups, dips, and straight bar bench pressing for chest and triceps strengthening could help lessen the strain on the AC joint. Incorporating other exercises like cable crossovers, dumbbell declines, inclines, and narrow grip bench press might help prevent and reduce the risk of DCO after being diagnosed.
