Quantifying Optimal Columellar Strut Dimensions for Nasal Tip Stabilization After Rhinoplasty via Finite Element Analysis

Gandy JR, Manuel CT, Leary RP, Wong BJ.

PubMed 26868130 Publisher (DOI)Free full text (PMC)

What this paper says

A computer engineering model of the nose found that tip support increased with the size of a columellar strut graft, and that stitching only the front portion gave the same support as stitching the whole length.

Overview

Columellar strut grafts support the nasal tip, but their mechanical contribution had never been calculated. The authors built a finite element model of a human nose from a CT scan, then simulated struts of different sizes and suture arrangements.

Sections of note

The model was built from a computed tomographic scan and included bone, skin and soft tissue, and cartilage.
Struts ranging from 15 by 4 by 1 mm to 25 by 8 by 1 mm were placed between the medial crura.
Two models were built per strut size: one sutured to the nasal spine, medial crura and caudal septum, one free to move in the soft tissue. A control model had no graft.
Reaction force increased as strut volume increased, while strain energy density across the tip cartilages generally decreased.
Struts sutured along their entire length generated a larger reaction force than unattached struts.
Struts sutured only at the front behaved like fully sutured ones, while those sutured only at the back behaved like unattached ones.

What it means for a patient

This is a computer simulation, not an operation on patients, so it reports forces rather than appearance, healing or satisfaction.
The finding supports what surgeons already do, that a bigger graft fixed in place gives a firmer tip.
Where the stitches go matters as much as how many there are, with the front of the graft doing the work.
One model built from one scan, no patient data, no follow-up, and no account of how tissue heals or scars around a graft.

Why this paper matters

Whether columellar struts actually support the tip has been argued from clinical impression, with published series reaching opposite conclusions. Structural mechanics offers an independent way to test the question. What a model cannot capture is biological healing, so it cannot settle whether struts change results in patients.

Terms

Columellar strut graft: a cartilage support placed between the nostrils to hold the tip.
Finite element model: a computer simulation dividing a structure into small elements to calculate forces.
Medial crura: the paired lower cartilages inside the columella that support the tip.
Nasal spine: the small bony projection at the base of the nose where the septum sits.
Reaction force: the force a structure pushes back with when loaded.

Summary written by rhinoplasty.cc from the abstract, 2026-09-08; not medical advice. The authors' own abstract follows.

Abstract

Importance: The contribution of columellar strut grafts (CSGs) to nasal tip support has not been determined via structural mechanics. Optimal graft dimensions have yet to be objectively determined.

Objectives: To use a finite element model (FEM) of the human nose to (1) determine the effect of the CSG on nasal tip support and (2) identify how suture placement contributes to tip support.

Design, Setting, And Participants: A multiple-component FEM of the human nose consisting of bone, skin/soft tissue, and cartilage was rendered from a computed tomographic scan. Then, CSGs of varying sizes were created, ranging from 15 × 4 × 1 mm to 25 × 8 × 1 mm, and placed in the model between the medial crura. Two FEMs were constructed for each strut size: (1) CSGs that were physically attached to the nasal spine, medial crura, and caudal septum and (2) CSGs that were not in direct contact with these structures and free to move within the soft tissue. A control model was also constructed wherein no graft was placed.

Main Outcomes And Measures: Nasal tip support for each model was assessed, and the resultant distribution of von Mises stress, reaction force, and strain energy density with respect to the alar cartilages were calculated.

Results: Compared with the control, the reaction force increased with increasing strut volume, while the strain energy density (calculated over the alar cartilages) generally decreased with increasing CSG volume. Simulations with struts that had suture attachments along the entire length of the graft generated a larger reaction force than the models without any suture attachments. Models with anteriorly placed sutures generated reaction forces similar to that of the fully sutured model, whereas the models with posterior sutures showed reaction forces similar to the fully disconnected model.

Conclusions And Relevance: Insertion of CSGs does effect the amount of force the nasal tip can withstand post rhinoplasty. Moreover, anteriorly placed sutures incur reaction forces similar to struts that are fully connected to the alar cartilage. Thus, our simulations are congruent with clinical practice in that stability increases with graft size and fixation, and that sutures should be placed along either the entire CSG or the anterior most portion for optimal support.

Level Of Evidence: NA.

Abstract as indexed by PubMed; the article is open access (PubMed Central).