Validation of an Instrumented Hammer for Rhinoplasty Osteotomies: A Cadaveric Study

Giunta J, Lamassoure L, Nokovitch L, Rosi G, Poudrel AS, Meningaud JP, Haïat G, Bosc R.

What this paper says

Using an instrumented hammer on nine human anatomic specimens, an algorithm predicted when the bone had fractured and how close the chisel was to the thicker frontal bone, with 83 percent accuracy on the exact impact.

Overview

Bone cuts during rhinoplasty are normally guided by the surgeon's sense of feel, which determines how many strikes to make, how hard and in what direction. The study aimed to detect when a fracture occurs and when the chisel reaches the thicker frontal bone. An instrumented hammer measured impact force during lateral bone cuts on cadaveric specimens, and a machine learning algorithm was built from the data.

Sections of note

Cadaveric study on nine human anatomic specimens.
An instrumented hammer measured impact force during lateral osteotomies.
A prediction algorithm was developed using machine learning techniques.
The algorithm predicted fracture occurrence and proximity to the frontal bone with a prediction rate of 83 percent when allowing no error in impact count.
Accuracy rose to 91 percent when allowing an error of one impact and 93 percent when allowing two.
The location of the chisel in the frontal bone was predicted with an error of 7.7 percent.
The stated conclusion is that such a hammer can give the surgeon instant feedback during the bone cut.

What it means for a patient

The bone cuts that narrow the nose are currently made by feel, with no direct confirmation that the bone has broken where intended.
The device is intended to signal both a completed fracture and the approach to thicker bone at the root.
This was tested on cadavers, not living patients, so tissue response and bleeding were absent.
Nine specimens is a small validation sample and no clinical outcomes were measured.

Why this paper matters

Bone cutting is the step in rhinoplasty most dependent on tactile experience and hardest to teach. This study tests whether that feedback can be measured and reported to the surgeon. Whether it improves the accuracy of bone cuts in living patients is untested.

Terms

Osteotomy: a controlled cut in bone so it can be repositioned.
Osteotome: a chisel used to cut bone.
Lateral osteotomy: the bone cut along the side of the nose used to narrow it.
Proprioception: the sense of position and force in one's own hands.
Machine learning: computer methods that find patterns in data to make predictions.
Cadaveric study: research performed on preserved human specimens.

Summary written by rhinoplasty.cc from the abstract, 2026-09-09; not medical advice. The authors' own abstract follows.

From the abstract

“Osteotomies during rhinoplasty are usually based on surgeon's proprioception to determine the number, energy, and trajectory of impacts. Objective: The first objective was to detect the occurrence of fractures. The second objective was to determine when the thicker frontal bone was encountered by the osteotome.…”

Excerpt; the full abstract is on PubMed.