The typical presentation for distal clavicular osteolysis (distal clavicular osteolysis), often called "weightlifter's shoulder," basically gives you the primary clue to this problem -- bench press, and especially during COVID, increasing volume of push-ups in the history associated with pain "on top" of the shoulder (note though that the pain can also mimic rotator cuff pathology, and in long-standing cases with bony exostosis of the AC joint be associated with true Neer-type external rotator cuff impingement).
Typical Patient Demographics¶
distal clavicular osteolysis typically affects young and middle-aged individuals. The average age is usually closer to the late 20s through mid-30s, though athletes as young as 13 may be affected.
Knowledge Check
DCO typically affects young and middle-aged individuals with average age in the late 20s through mid-30s, particularly those participating in weightlifting and overhead sports.
The condition is most prevalent in males. However, it is also reported in women, particularly with the rise in participation in body building and extreme athletics.
Patients commonly participate in activities that subject the shoulder girdle to repetitive microtrauma and heavy loads. High-risk populations include:
• Weightlifters, bodybuilders, and powerlifters.
• Overhead athletes such as baseball, softball, basketball, volleyball, tennis, and swimming players.
• Individuals performing heavy manual labor.
The combination of an overhead sport and a supplemental weightlifting program is noted as a strong risk factor for atraumatic distal clavicular osteolysis in younger patients. Symptoms may preferentially affect the dominant side in overhead athletes.
Symptoms and History¶
Patients generally present with dull, aching pain localized to the ipsilateral shoulder or acromioclavicular joint (ACJ).
Pain Characteristics and Triggers:¶
• The pain is exacerbated by repetitive loading, strenuous overhead activities, and weightlifting.
• Specific movements that worsen symptoms include bench press, push-ups, parallel bar dips, shoulder shrugs, military press, and clean and jerk.
• Pain may also be reproduced or worsened by shoulder adduction (like the cross-body adduction test).
• Patients may report their discomfort is diffuse with radiation to the trapezius or deltoid muscles.
• Pain may be significantly worse the night after a weightlifting session.
• Certain sleep positions, such as side-lying with the arm flexed and adducted at the shoulder, tend to further exacerbate symptoms.
• Patients tend to report short-term resolution of their symptoms during periods of rest with recurrence following resumption of activity.
Onset and Etiology: The presentation varies based on the two main etiologies: posttraumatic and atraumatic distal clavicular osteolysis.
• Atraumatic distal clavicular osteolysis: Characterized by the gradual onset of pain without a clear inciting event. Early in the disease process, pain may be minimal, often resulting in a delayed presentation, typically diagnosed in the subacute or chronic stage after three or more months of symptoms.
• Posttraumatic distal clavicular osteolysis: Patients may recall a distinct injury to the shoulder, such as a fall, collision, motor vehicle accident (often resulting in ACJ dislocation/separation or clavicular fracture) prior to the onset of their symptoms. The timeline for symptom onset is variable, ranging anywhere from 2 months to a year after the injury.
Physical Examination¶
The clinical examination should include inspection, palpation, and special testing.
• Inspection and Palpation:¶
◦ Inspection may reveal trace to minimal soft tissue edema or swelling when compared to the contralateral side.
◦ The hallmark finding on physical examination is point tenderness (tenderness to palpation) localized at the distal clavicle or ACJ. This finding has been shown to be highly sensitive (96%) for ACJ pathology.
• Range of Motion (ROM):¶
◦ Range of motion of the glenohumeral joint is generally preserved.
◦ Pain may be present with forward flexion past 90 degrees and abduction, particularly when combined with adduction.
◦ Patients may avoid terminal active shoulder ROM, especially full forward flexion and extension, due to pain.
• Special Testing:
Manoeuvres that stress the ACJ are typically positive.
◦ The Cross-body adduction stress test (Scarf Test), which involves fully adducting the arm across the body, typically reproduces localized ACJ pain.
◦ The combination of ACJ palpation and the O'Brien active compression test has been found to be highly sensitive and specific when screening for ACJ pathology and distal clavicular osteolysis.
◦ Other tests include the Resisted AC extension test and the Paxinos test.
• Neurological Assessment: Generally, there is no significant weakness. Where the rest of the history and physical exam seems atypical, don't forget the possibility of neural injury to the lateral pectoral nerve or suprascapular nerve should be investigated as a possible source of ACJ pain.
The overlap in clinical presentation between distal clavicular osteolysis, ACJ osteoarthritis, and in long-standing cases rotator cuff/subacromial pathology can make early diagnosis challenging for clinicians. Confirmation of an exact diagnosis in these cases may not be possible, and is likely multiple, and overlapping.
Management¶
Management for distal clavicular osteolysis (distal clavicular osteolysis) is primarily guided by patient-specific factors, including activity level, age, and desire to return to competition. Early recognition and treatment are essential to prevent progression to acromioclavicular joint (ACJ) pathology or instability.
The treatment strategy follows a staged approach, beginning with nonoperative care, which is successful in the majority of cases.
I. Conservative (Nonoperative) Management¶
Activity modification and rehabilitation are the mainstays of initial treatment for distal clavicular osteolysis. distal clavicular osteolysis is generally considered a self-limiting disorder that resolves within one to two years with significant activity modification, this of course will be cold comfort to athletes you are treating,
Short-Term Treatments and Strategies
Initial management typically incorporates multiple strategies aimed at reducing mechanical stress and inflammation:
1. Rest and Medication: Patients are advised to use relative rest (i.e. prevention of activity which involves compression of the A-C joint -- particularly resisted shoulder internal rotation, especially with scapular protraction). You can also think about the old standbys of: ice, topical analgesics, and anti-inflammatory medications (NSAIDs) -- noting of course all the usual patient warnings. If these are going to help, you should see a benefit within a couple of applications, otherwise I wouldn't be persisting with them. Immobilization in a sling is unnecessary and should be avoided lest you encourage a protracted scapular posture.
2. Activity Modification: This is considered the first step in treatment. Like all bone stress injury, which this essentially is, resolution is slower, and patient education is going to be key to gaining compliance, and therefore good outcomes
◦ For mild symptoms (occurring only with weightlifting/sport), removing specific movement patterns for 4 to 8 weeks with a gradual return to activity may be sufficient -- take note especially of scapular positioning during loading.
◦ In more severe cases where pain occurs even with daily activities, 4 to 8 weeks of restriction from both sport and weightlifting may be necessary.
◦ Aggravating exercises such as bench press, push-ups, and dips should be removed or replaced with alternatives (e.g., dumbbell press, cable crossover).
◦ If weightlifting must continue, technique modifications are crucial, such as using a medium grip width (1.5 times biacromial distance) and controlling the barbell descent to end 4 to 6 inches (or 4 to 6 cm) above the anterior chest to reduce shoulder extension moments. Competitive pitchers should decrease throwing volume.
3. ACJ Injections: Ultrasound-guided ACJ injections of anaesthetic and sometimes even the dreaded corticosteroid may be used as an adjunct treatment for persistent pain but only after thoroughly explaining the nature of this along with the likely deleterious effect on the chondral surfaces, intra-articular disk (assuming it's still there) and the adjacent superior rotator cuff.
◦ Injections offer a diagnostic benefit (confirming the ACJ as the source of pain) and can provide reliable prognostic information for the success of later surgical resection.
◦ However, the relief is often temporary or short-lived; one study noted the mean duration of efficacy was 20 days.
◦ Injections should not be used in lieu of activity modifications or rehabilitation due to the risk of continued osteolysis and disease progression.
Short and Long-Term Outcomes of Conservative Management¶
• Success Rate (Short/Mid-Term): Conservative management is highly effective. Outcome studies suggest success in about 80-90% of cases.
Knowledge Check
Conservative management is highly effective for DCO, with outcome studies showing success in about 80-90% of cases, making it the first-line treatment approach.
• Return to Activity (Short-Term): In most cases, the anticipated timeline for full return to sport following conservative treatment is 3 to 6 months. In a study of young patients (age 13-19), 93% were successfully treated conservatively.
• Long-Term Sequelae (If Unresolved/Delayed Diagnosis): If distal clavicular osteolysis is incompletely treated, continuous overhead activity can cause progression. The lytic phase can continue for 12 to 18 months, potentially absorbing 0.5--3 cm of the distal clavicle. Long-term follow-up (average 4.3 years) in young patients who had distal clavicular osteolysis showed that they were at increased risk for developing:
◦ Widening of the AC Joint: A mean interval widening of 2.6 mm was observed, resulting in a mean follow-up width of 5.0 mm (compared to 2.4 mm in controls).
◦ AC Joint Osteoarthritis (OA): Secondary ACJ OA was present in 71% of distal clavicular osteolysis patients on follow-up imaging, compared to 35% in controls. The severity of the initial distal clavicular osteolysis grade was associated with the subsequent development of ACJ OA.
II. Operative Management¶
Surgery is reserved for patients whose conditions are refractory to conservative management, generally after a minimum of 3 to 6 months of physician-directed treatments. It is also indicated for high-level athletes who are unable or unwilling to modify their activities or require an early return to competition.
The typical surgical procedure is distal clavicular resection (distal clavicular resection). Arthroscopic techniques are generally favoured over open procedures (Mumford procedure) due to decreased morbidity, less tissue dissection, quicker recovery time, improved cosmesis, and the ability to evaluate concomitant shoulder pathology.
Surgical Techniques and Approach Outcomes¶
• Resection Amount: Typically, 4 to 7 mm of the distal clavicle are removed. The amount should be sufficient to prevent AC impingement through a full range of shoulder motion.
Knowledge Check
Typically 4 to 7 mm of the distal clavicle is removed during surgical resection, which is sufficient to prevent AC impingement through a full range of shoulder motion.
• Arthroscopic Approaches: Both the indirect (subacromial) and direct (superior) approaches yield successful clinical outcomes.
◦ Direct (Superior) Approach: This is currently the preferred approach for isolated distal clavicular osteolysis. It offers a quicker return to sport and a lower risk of inadequate resection compared to the indirect approach. In a comparative study, the direct group returned to sport-specific activities significantly faster (average 21 days vs. 42 days).
◦ Indirect (Subacromial/Bursal) Approach: This approach is more advantageous if the surgeon needs to simultaneously address other shoulder pathology in the subacromial space.
Surgical Outcomes (Short-Term)¶
• Return to Activity: Patients typically return to daily activities within 1 to 2 weeks.
• Return to sport activities is generally achieved within 3 to 6 weeks.
• A study of weightlifters treated with limited arthroscopic distal clavicular resection showed patients resumed training within the first week (average 3.2 days) and returned to preoperative weight training levels after an average of 9.1 days. Formal physical therapy is typically initiated for the next 2 to 3 weeks following surgery, with a gradual return to functional and sport-specific activities.
Surgical Outcomes (Long-Term)¶
• Overall Success: Arthroscopic resection of the distal clavicle provides excellent results. At long-term follow-up (mean 6.2 years), distal clavicular resection using a direct superior approach resulted in good or excellent results in 93% of shoulders.
• Strength and Function: Strength appears to be maintained after arthroscopic surgery. Patients who undergo successful surgery report significant improvement in pain, with 93% having mild or no pain postoperatively, compared to 98% having moderate to severe pain preoperatively.
• Prognostic Factors: The aetiology of distal clavicular osteolysis impacts long-term outcome. Patients with posttraumatic distal clavicular osteolysis had slightly worse long-term outcomes (pain, functional limitations) compared with atraumatic distal clavicular osteolysis cases. In one long-term study, the three reported failures all occurred in patients with a history of trauma, suggesting potential underlying subtle ACJ instability. Patients with posttraumatic distal clavicular osteolysis may require a longer rehabilitation course to address biomechanics.
• Complications/Failures: Failures following distal clavicular resection may be related to inadequate bone resection or iatrogenic AC joint instability. In cases where excessive instability results in continued pain, an open stabilization procedure may be necessary.