If hearing is not enough, neither is touch
Before surgery, muscle positions are drawn on the skin. That drawing is made by touch, from the surgeon's experience. This study compared it against ultrasound in 100 patients with 5 surgeons, and the result is uncomfortable: even on the midline — the easiest structure to find — palpation and ultrasound agreed only 49% of the time. For every other structure, between 11% and 26%.
The finding, unsoftened
Agreement was measured structure by structure. These are the rates at which the palpation-based drawing matched what ultrasound showed:
| Structure | Agreement |
|---|---|
| Midline | 49% |
| Oblique triangle | 26% |
| Semilunar line | 23% |
| Lower edge of pectoral muscles | 16% |
| Diastasis recti · serratus anterior · subcostal triangle | 15% |
| Border of oblique muscle | 13% |
| Upper edge of rectus abdominis · number of tendinous intersections | 12% |
| Shape of tendinous intersections | 11% |
The authors report P < 0.0001 for most structures: the difference is not chance.
Why this is the twin of the «clack» study
In rib remodeling it was shown that the fracture sound was heard in 90% of cases while ultrasound confirmed it in 100%: hearing missed one in ten.
This paper says the same about touch, and more forcefully. Both point to one principle: the surgeon's senses are instruments with a measurable margin of error, and ultrasound corrects it. It is not a convenience accessory.
What this study does not say
It does not say surgeons are careless, nor that palpation is useless: it says each patient's anatomy varies more than touch can resolve. It also does not measure surgical outcomes — it compares drawings, not operations. And the creator of the rib remodeling technique is its first author, so this is not independent work.