Execution
- 1Perform Paxinos sign and scores it positive only if AC-region pain is reproduced.
- 2Perform O’Brien active compression and scores it positive only if pain is localized to the AC joint.
- 3Interpret the cluster as positive when both Paxinos and O’Brien are positive.
- 4Separate AC pain from deep glenohumeral / labral pain during O’Brien testing.
- 5Use the cluster to support, not prove, symptomatic AC-joint pathology.
Positive outcome
Positive Paxinos sign followed by positive AC-localized O’Brien test supports symptomatic AC-joint pathology. The cluster is intended as a rule-in-oriented Krill grouping.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Krill et al. (2018) — systematic review | NA | NA | 95.8 | 2.71 | NA |
CommentKrill’s proposed cluster is pragmatic but only moderately useful; LR+ around 2.7 is far weaker than the classic Chronopoulos framing. It is still useful because individual AC tests perform inconsistently. Avoid overstating it as a high-certainty rule-in cluster.
Moderate Clinical Value