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Distal Clavicle Osteolysis

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Other Names

  • Weightlifter’s Shoulder
  • Weightlifter Shoulder
  • Distal Clavicular Osteolysis
  • Osteolysis of the Distal Clavicle
  • Traumatic Osteolysis of the Distal Clavicle
  • Atraumatic Osteolysis of the Distal Clavicle
  • AC Joint Osteolysis
  • Acromioclavicular Joint Osteolysis
  • Stress Osteolysis of the Distal Clavicle

Background

  • This page referes to Distal clavicle osteolysis (DCO) is a stress-related condition of the distal clavicle

History

  • The atraumatic (overuse) form was brought to widespread attention by Cahill in 1982[1]
  • Cahill formalized the term "atraumatic osteolysis of the distal clavicle" in 1992[2]

Epidemiology

  • Most commonly affects young, active males, particularly those engaged in weightlifting and strength training[3]
  • Prevalence was 6.5% in a study of 1,432 consecutive shoulder MRIs in patients aged 13–19 years[4]

Introduction

Progressive osteolysis and tapering of the distal clavicle.[5]
Illustration of the acromioclavicular joint[6]

General

  • Stress-related overuse injury causing osteolysis of the distal clavicle at the AC joint
  • Caused by repetitive microtrauma and subchondral microfractures
  • Common in weightlifters and athletes performing repetitive overhead activity
  • Imaging may show distal clavicle bone loss, cystic changes, erosions, and AC joint widening
  • Most patients improve with conservative treatment including activity modification, NSAIDs, and injections

Pathophysiology

  • Fundamental mechanism[7]
    • Involves repetitive microtrauma causing subchondral microfractures within the distal clavicle
    • This triggers a cascade of bone resorption and failed healing
  • Subchondral fractures[7]
    • MRI studies demonstrate subchondral fracture lines within the distal clavicular edema in 86% of cases
    • Believed to explain why osteolytic findings preferentially occur on the clavicular side
    • distal clavicle bears disproportionate compressive and shear forces
  • Histology[8]
    • Disruption of articular cartilage
    • Subchondral cysts
    • Metaplastic bone formation
    • Increased osteoclastic activity
  • Stress failure syndrome concept
    • AC joint represents the biomechanical "weak link" in the musculoskeletal chain
    • Cumulative exercise doses exceed the bone's capacity for repair

Etiology

  • Atraumatic (overuse/stress-related)
    • Most common form
    • Occurs in athletes with no history of acute AC joint injury
    • Most commonly report prolonged, intense strength training — particularly bench pressing and chest flies
  • Post-traumatic[9]
    • Occurs following a single acute injury to the AC join
    • Radiographic and MRI appearances are similar to the atraumatic form
  • Systemic/metabolic
  • Idiopathic
    • Distinct category of bilateral DCO unrelated to trauma, overuse, or metabolic disease

Anatomy of the Acromioclavicular joint

Associated Conditions

  • AC Joint Osteoarthritis[4]
    • Most significant long-term sequela, occurring in 71% of DCO patients
    • Severity of initial edema predicting development of OA
  • AC joint widening
  • Glenoid Labral Tears
    • Found in 36% of DCO patients on MRI, not significantly different from age matched controls[7]* Partial Thickeness Rotator Cuff Tears
    • Found in 22% of DCO patients (vs. 28% in controls), not staistically significant
  • AC joint effusion
    • Present in 89% of DCO cases on MRI
  • Acromial osteolysis
  • SAPHO syndrome and chronic recurrent multifocal osteomyelitis (CRMO)[10]
    • Nonbacterial inflammatory conditions that can involve the clavicle
    • Should be considered in the differential diagnosis of clavicular osteolysis, particularly when bilateral or multifocal

Risk Factors

Demographic

  • Male sex
  • Young age

Exercise Intensity

  • High-intensity bench pressing (>1.5× body weight 1RM)[11]
    • Strongest exercise-related risk factor
  • Low-intensity bench pressing (<1.5× body weight 1RM)
    • Not associated with increased risk

Exercise Frequency & Duration

  • Bench pressing >1×/week
  • Bench pressing for >5 years
  • Long cumulative training history

Activity-Related Risk Factors

  • Overhead sports + supplemental weight training
    • Markedly increased risk[4]
  • Weightlifting / strength training
  • Repetitive overhead activity
  • Chest flies and pressing exercises
  • Repetitive occupational overhead work

Trauma-Related Risk Factors

  • Prior AC joint trauma
    • Including AC sprains, direct shoulder trauma, distal clavicle fractures
  • Repetitive microtrauma / overuse

Systemic / Metabolic Risk Factors

Differential Diagnosis

Differential Diagnosis Shoulder Pain

Clinical Features

Typical pain location for DCO

History

  • Anterior/ superior shoulder pain
    • Onset of pain is typically insidious and gradual
    • Localizes to the area of the AC joint
    • Worse with bench press, chest flies, dips, push ups
    • Uncommonly, there is a history of trauma
  • Symptoms are usually present for >12 months before evaluation
  • Patients report a decrease in performance over time
  • Bilateral symptoms should raise suspicion for idiopathic or systemic causes[12]

Physical Exam: Physical Exam Shoulder

  • The AC Joint may appear thickened or swollen[13]
    • Visible prominence or asymmetry of the distal clavicle may be present
    • Look for muscle bulk asymmetry suggesting disuse
  • Tenderness localizes directly over the AC joint
    • This is present in 96% of patients with injection confirmed AC joint pathology[14]
  • Range of motion can be decreased
  • Strength is typically preserved unless pain related
    • Weakness may be present with resisted horizontal adduction or forward flexion due to pain inhibition
  • Neurovascular exam is normal

Special Tests

Evaluation

Distal clavicle osteolysis s/p surgical resection[15]
Osteolysis of the distal clavicle. Oblique coronal T1-weighted (A) and fast spin-echo fat-saturated T2-weighted (B) images of the shoulder show edema in the distal clavicle, widening of the acromioclavicular joint, and erosive changes in the articular surface of the distal clavicle (curved arrows). Periosteal reactive changes are not uncommon (straight arrow in B).[16]
Ultrasound of a patient with post-traumat DCO Right showing AC joint space widening, capsular thickening and effusion[17]

Radiographs (X-ray)

  • Standard Radiographs Shoulder
    • First line imaging
    • Can distinguish DCO from other AC Joint Pathology
  • Zanca View[18]
    • AP radiograph with 10–15° cephalic tilt and reduced exposure (50% of standard AP)
    • Provides optimal visualization of the AC joint and distal clavicle and is the preferred radiographic view
  • Early findings[19]
    • Soft tissue swelling over the AC joint
    • Demineralization/osteopenia of the distal clavicle
    • Loss of the subchondral cortex at the clavicular tip
  • More classic/ established findings[20]
    • Subchondral cystic changes
    • Cortical irregularity
    • Erosions of the distal clavicle
  • Advanced findings
    • Frank osteolysis with resorption of the distal clavicle
    • Widening of the AC joint space
  • Healing/chronic findings[21]
    • Reconstitution of the distal clavicle of varying degrees on follow-up radiographs
    • Radiographic improvement lags behind clinical improvement

MRI

  • General
    • Most sensitive modality for detecting DCO
    • Particularly in early stages when radiographs are normal or equivocal
    • Recommended when clinical suspicion is high but radiographs are nondiagnostic
  • Findings[22]
    • Bone marrow edema of the distal clavicle
      • Most common and conspicuous finding
      • Present in 100% of cases across multiple series
    • Acromion edema (47–63% of cases)
    • Cortical irregularity (71–86% of cases)
    • Subchondral cysts/erosions (43–75% of cases)
    • AC joint capsule prominence (82% of cases)
    • AC joint fluid (47–89% of cases)
    • Subchondral fracture line (86% of cases)
    • Bone fragmentation (35% of cases)
    • Periostitis (38% of post-traumatic cases)
  • Additional considerations
    • Severity of distal clavicle edema on initial MRI correlates with pain at presentation
    • Follow-up MRI in patients who respond to conservative therapy shows normalization of marrow signal intensity
    • Associated findings: partial-thickness rotator cuff tears (22%) and labral tears (36%), not significantly different from controls

CT

  • Limited role in evaluation of DCO
  • Provides excellent visualization of cortical detail, subchondral cysts, and erosive changes[23]
  • CT-guided AC joint injection has been described as both a diagnostic and therapeutic tool[24]
  • CT is most useful when there is concern for fracture, neoplasm, or infection as alternative diagnoses

Ultrasound

  • Limited role in evaluation of DCO
  • Ultrasound cannot assess bone marrow edema or subchondral changes
  • Potential utility includes
    • Useful for excluding AC joint inflammation
    • Can guide diagnostic and therapeutic AC joint injections

Bone Scan

  • Has largely fallen out of favor for other imaging modalities
  • In Cahill's original series, joint scintigraphy showed increased activity in the distal clavicle in 100% of patients[1]

Classification

  • There is no widely accepted, validated classification or staging system

Management

Nonoperative

  • Conservative therapy is the first-line treatment for distal clavicle osteolysis.
  • Activity modification
    • Avoidance or reduction of aggravating activities
    • Eg.g. bench press, chest flies, dips, and overhead lifting
  • NSAIDS and other topical agents
  • Acromioclavicular Joint Injection
  • Sling immobilization and ice
    • Particularly in post-traumatic cases
  • Physical Therapy
    • Physiotherapeutic modalities, range-of-motion exercises, and gradual return to activity

Operative

  • Indications
    • Failure of conservative management
  • Technique
    • Distal clavicle resection (Mumford procedure)
    • Can be open or arthroscopic (preferreD)

Rehab and Return to Play

Distal Clavicle Osteolysis Rehab Programs

PHASE I — Protection & Early Motion (Weeks 0–2)

  • Goals: Pain/swelling control, protect repair, maintain distal mobility, initiate gentle ROM
  • Sling for comfort (typically 3–7 days; discontinue as tolerated)
  • Cryotherapy and analgesics/NSAIDs as needed
  • Exercises
    • Pendulum (Codman) exercises starting POD 1
    • Passive and active-assisted ROM:
    • Forward flexion ≤90°
    • External rotation ≤30° in scapular plane
    • Scapular isometrics (retraction/depression)
    • Grip strengthening
    • Elbow and wrist AROM
  • Avoid: cross-body adduction, resisted shoulder motion, lifting >1 lb

PHASE II — Progressive ROM & Early Strengthening (Weeks 2–4)

  • Goals: Restore passive ROM, initiate active ROM, begin scapular strengthening
  • Progress to full passive ROM by week 4
  • Active-assisted → active ROM: flexion, abduction, external/Internal rotation
  • Scapular stabilization: rows, band retraction exercises, prone T, Y, I exercises
  • Isometric shoulder strengthening: flexion, abduction, external/Internal rotation
  • Avoid: heavy lifting, push-ups, dips, bench press, overhead pressing

PHASE III — Strengthening (Weeks 4–8)

  • Goals: Full AROM, improve strength, restore neuromuscular control
  • Full AROM expected by weeks 4–6
  • Rotator cuff strengthening with bands/light weights: ER/IR, supraspinatus
  • Deltoid strengthening: front raises, lateral raises
    • Start with 1–2 lb and progress
  • Closed-chain progression: wall push-ups → Countertop push-ups
  • Upper body ergometer (UBE)
  • Neuromuscular/proprioceptive training: rhythmic stabilization, ball-on-wall drills
  • Avoid: bench press, chest flies, dips, heavy overhead pressing

PHASE IV — Advanced Strengthening & Sport-Specific Training (Weeks 8–12)

  • Goals: Restore full strength and prepare for return to sport
  • Progressive resistance training
  • Modified bench press: narrow grip, limited ROM initially, progress to full ROM
  • Light overhead pressing → gradual progression
  • Plyometrics: medicine ball chest passes, overhead throws
  • Sport-specific progression:
  • Weightlifters:
    • Bench press and overhead press beginning at ~50% pre-injury loads
    • Overhead athletes: Interval throwing/serving program
    • Contact athletes: Non-contact sport drills
  • Continue rotator cuff and scapular stabilization program

PHASE V — Return to Play (Weeks 10–16+)

  • Return-to-Play Criteria
    • Pain-free full ROM equal to contralateral side
    • Strength ≥90% of contralateral side
    • No AC joint tenderness
    • No pain with cross-body adduction test
    • Successful sport-specific functional testing
    • Subjective confidence in shoulder function
  • Sport-Specific Clearance
    • Weightlifters: Pain-free bench press, overhead press, and chest flies at pre-injury loads
    • Overhead athletes: Complete throwing/serving program without symptoms
    • Contact athletes: Full-contact practice without symptoms
  • Expected Return-to-Sport
    • Arthroscopic (direct): ~3 weeks average
    • Arthroscopic (indirect): ~6 weeks average
    • Open procedure: 8–12+ weeks

Prognosis and Complications

Prognosis

  • Etiology (Traumatic vs. Atraumatic/Overuse)
    • Atraumatic (overuse/microtraumatic) etiology is associated with significantly better outcomes[25]
  • Amount of Bone Resected
    • Resection ≤10 mm is associated with significantly less postoperative pain than larger resections[26]
    • Limited resection in weight lifters yielded excellent outcomes with return to full training in ~9 days
    • Excessive resection leads to irreparable pain and dysfunction[27]
  • Surgical Approach
    • Arthroscopic techniques yield more "good or excellent" results than open procedures[28]
    • The direct (superior) approach permits faster return to sport (mean 21 days) compared to the indirect approach (mean 42 days)[29]
  • Concomitant Pathology
    • DCE performed in conjunction with subacromial decompression or rotator cuff repair has a high degree of success[28]

Complications

  • AC Joint Instability (Iatrogenic)
    • Excessive resection or capsular disruption leads to anteroposterior instability of the remaining clavicle
  • Excessive Bone Resection
  • Persistent Pain
    • Reported in up to 63% of patients in one open DCE series[30]
  • Decreased Strength
    • Eighteen of 73 patients (25%) reported decreased strength of the involved upper extremity
  • Loss of Range of Motion
  • Scar Hypertrophy
  • Contralateral Disease Development
  • Heterotopic Ossification / Bone Regrowth
  • General Surgical Complications

See Also

References

  1. ↑ 1.0 1.1 Cahill, B. R. "Osteolysis of the distal part of the clavicle in male athletes." JBJS 64.7 (1982): 1053-1058.
  2. ↑ Cahill, Bernard R. "Atraumatic osteolysis of the distal clavicle: a review." Sports Medicine 13.3 (1992): 214-222.
  3. ↑ DeFroda, Steven F., et al. "Diagnosis and management of distal clavicle osteolysis." Orthopedics 40.2 (2017): 119-124.
  4. ↑ 4.0 4.1 4.2 Roedl, Johannes B., et al. "Frequency, imaging findings, risk factors, and long-term sequelae of distal clavicular osteolysis in young patients." Skeletal radiology 44.5 (2015): 659-666.
  5. ↑ Nissen KS, Bedeir YH, Grawe BM. Severe and rapid post-traumatic osteolysis of the distal clavicle in a college athlete: a case report and review of the literature. Surg Case Rep. 2020;3(6). doi:10.31487/j.SCR.2020.06.09.
  6. ↑ Image courtesy of teachmeanatomy, "The Acromioclavicular Joint"
  7. ↑ 7.0 7.1 7.2 Kassarjian, Ara, Eva Llopis, and William E. Palmer. "Distal clavicular osteolysis: MR evidence for subchondral fracture." Skeletal radiology 36.1 (2007): 17-22.
  8. ↑ Patten, Randall M. "Atraumatic osteolysis of the distal clavicle: MR findings." Journal of computer assisted tomography 19.1 (1995): 92-95.
  9. ↑ Mestan, Michael A., and John M. Bassano. "Posttraumatic osteolysis of the distal clavicle: analysis of 7 cases and a review of the literature." Journal of Manipulative and Physiological Therapeutics 24.5 (2001): 356-361.
  10. ↑ Jiang, Nan, et al. "Similarities and differences between clavicular bacterial osteomyelitis and nonbacterial osteitis: comparisons of 327 reported cases." Journal of Immunology Research 2021.1 (2021): 4634505.
  11. ↑ Nevalainen, Mika T., et al. "Distal clavicular osteolysis in adults: association with bench pressing intensity." Skeletal radiology 45.11 (2016): 1473-1479.
  12. ↑ Hawkins, Bryan J., D. C. Covey, and Brent G. Thiel. "Distal clavicle osteolysis unrelated to trauma, overuse, or metabolic disease." Clinical Orthopaedics and Related Research® 370 (2000): 208-211.
  13. ↑ Cadogan, Angela, et al. "Shoulder pain in primary care: diagnostic accuracy of clinical examination tests for non-traumatic acromioclavicular joint pain." BMC Musculoskeletal Disorders 14.1 (2013): 156.
  14. ↑ Walton, Judie, et al. "Diagnostic values of tests for acromioclavicular joint pain." JBJS 86.4 (2004): 807-812.
  15. ↑ Alentorn-Geli, Eduard, et al. "Distal Clavicle Osteolysis after Modified Weaver‐Dunn’s Procedure for Chronic Acromioclavicular Dislocation: A Case Report and Review of Complications." Case Reports in Orthopedics 2014.1 (2014): 953578.
  16. ↑ Lenobel, Scott S., and Joseph S. Yu. "Imaging of weight-lifting injuries." Imaging in Sports-Specific Musculoskeletal Injuries. Cham: Springer International Publishing, 2016. 585-621.
  17. ↑ Case courtesy of Maulik S Patel, Radiopaedia.org, rID: 12812
  18. ↑ Peebles, Liam A., et al. "Management of Acromioclavicular Joint Injuries: A Historic Account." Clinics in Sports Medicine 42.4 (2023): 539-556.
  19. ↑ Hodges, Paul C., and William C. Allen. "Post-traumatic osteolysis of the distal clavicle." Postgraduate Medicine 41.3 (1967): A-73.
  20. ↑ Kaplan, Phoebe A., and Donald Resnick. "Stress-induced osteolysis of the clavicle." Radiology 158.1 (1986): 139-140.
  21. ↑ Mestan, Michael A., and John M. Bassano. "Posttraumatic osteolysis of the distal clavicle: analysis of 7 cases and a review of the literature." Journal of Manipulative and Physiological Therapeutics 24.5 (2001): 356-361.
  22. ↑ De La Puente, Rosa, et al. "Post-traumatic and stress-induced osteolysis of the distal clavicle: MR imaging findings in 17 patients." Skeletal radiology 28.4 (1999): 202-208.
  23. ↑ Ernberg, Lauren A., and Hollis G. Potter. "Radiographic evaluation of the acromioclavicular and sternoclavicular joints." Clinics in sports medicine 22.2 (2003): 255-275.
  24. ↑ Sopov, V., et al. "Stress-induced osteolysis of distal clavicle: imaging patterns and treatment using CT-guided injection." European Radiology 11.2 (2001): 270-272.
  25. ↑ Zawadsky, Mark, et al. "Osteolysis of the distal clavicle: long-term results of arthroscopic resection." Arthroscopy: The Journal of Arthroscopic & Related Surgery 16.6 (2000): 600-605.
  26. ↑ Eskola, Antti, et al. "The results of operative resection of the lateral end of the clavicle." JBJS 78.4 (1996): 584-7.
  27. ↑ Meshram, Prashant, et al. "Iatrogenic excessive clavicle resection as a complication of arthroscopic distal clavicle excision." Orthopedics 47.1 (2024): e57-e60.
  28. ↑ 28.0 28.1 Pensak, Michael, et al. "Open versus arthroscopic distal clavicle resection." Arthroscopy: The Journal of Arthroscopic & Related Surgery 26.5 (2010): 697-704.
  29. ↑ Charron, Kevin M., Anthony A. Schepsis, and Ilya Voloshin. "Arthroscopic distal clavicle resection in athletes: a prospective comparison of the direct and indirect approach." The American journal of sports medicine 35.1 (2007): 53-58.
  30. ↑ Chronopoulos, Efstathis, et al. "Complications after open distal clavicle excision." Clinical orthopaedics and related research 466.3 (2008): 646-651.
Created by:
John Kiel on 28 May 2026 13:09:48
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1 June 2026 15:05:26
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