# Involvement of the acromion in cases of distal clavicular osteolysis

## TL;DR

This study identifies a new variant of shoulder pain condition involving both the acromion and clavicle, linked to weightlifting and male sex.

## Contribution

The paper introduces a previously uncharacterized variant of distal clavicular osteolysis involving the acromion.

## Key findings

- 32.8% of DCO cases involved osteolysis of the acromion in addition to the distal clavicle.
- Male sex and higher maximum bench press weight were significantly associated with acromial involvement.
- Osteolysis involving the acromion suggests a more extensive disease variant.

## Abstract

Distal clavicular osteolysis (DCO) is a commonly encountered cause of shoulder pain resulting from repetitive overuse or antecedent trauma, classically described in young male weightlifters. We propose a variant of DCO in which osteolysis spans the acromioclavicular joint, involving both the anterior acromion and the distal clavicle.

A retrospective PACS query identified patients with DCO on shoulder MRIs performed at ≥ 1.5 T over a 1-year period. After inclusion/exclusion criteria were applied, each case was reviewed in a blinded fashion to assess for additional findings of osteolysis involving the acromion. Demographics and patient questionnaire data were recorded and analyzed for statistical significance between groups.

A total of 128 cases of DCO were identified in 127 patients (93 males). Mean age was 39.5 years (SD 11.3 years). Average symptom duration was 409 days (13.4 months). Per questionnaires, 45.3% had a history of antecedent trauma, 62.5% reported lifting weights, 38.3% reported overhead sports, and 32.0% reported repetitive activities. Of the 128 cases, 42 (32.8%) had additional findings of osteolysis involving the acromion. Acromial involvement was seen more commonly in males (p = 0.049). Other than sex, maximum bench press weight was the only statistically significant factor associated with acromial involvement (p = 0.027).

We identified a variant of DCO with osteolysis involving the acromion in addition to the distal clavicle. Other than male sex, maximum bench press weight was the only significant factor associated with acromial involvement, suggesting that increased load bearing may contribute to more extensive osteolysis.