Alar cartilage shape — Concavity, undulation and amorphous tip
What shape a normal alar cartilage has, which shadows betray that it does not, and how each deformity is corrected: from suture to strut graft and turn-in flaps of the cartilage itself.
Content intended for healthcare professionals. It does not replace clinical assessment and is not written as patient information.
Key points
- A normal alar cartilage is a smooth, continuous convexity from dome to sesamoids. Any abrupt change translates on the skin as an abnormal shadow or highlight.
- Assessment is visual and tactile: you look for where continuity breaks, not for how much cartilage there is.
- The amorphous tip is the commonest sequela of secondary rhinoplasty, and almost always follows over-resection, division or crushing.
- The current trend is to reorient and reinforce the patient’s own cartilage rather than resect it: alar turn-in flaps preserve structure instead of removing it.
- In thin skin any edge, graft or irregularity shows through. It is where smoothing matters most and stacking is least advisable.
What a normal alar cartilage looks like, inside and out
The normal shape of the lower lateral cartilage is a smooth convexity beginning at the dome, extending laterally to the sesamoid cartilages and descending convergently along the intermediate crura to end in the medial crura. What that produces on the surface is equally characteristic: smooth contours, no shadows, no abrupt changes. Laterally, between tip lobule and ala, only the alar groove line should be visible; inferiorly, between lobule, infratip and columella, the transition should be continuous. When any other conspicuous shadow or highlight appears, the cartilage beneath has lost that continuity.
Light is the diagnostic instrument
Shape alterations are not diagnosed by measuring: they are diagnosed by watching how light falls on the tip. Undulations, prominences and depressions of the cartilage appear as abnormal shadows and highlights in the overlying skin. Examine with lateral, diffuse light, not overhead, and move the source: contour defects appear and vanish with the angle. Then palpate, because thick skin damps the relief and can hide a deformity that becomes evident once the oedema settles, months after surgery.
Excessively concave alar cartilages
It is not common, but gives the tip a very unpleasant appearance: the concavity creates surface irregularities that appear as odd highlights and shadows. Treatment is complex and stepwise. In mild cases it may suffice to fill the depression with a cartilage graft or modify the curvature with intra-alar sutures. In marked cases, grafts that impose shape are needed: strut beneath the lateral crus, onlay over the alar cartilage, or alar rim grafts to support the border.
The manoeuvre of turning the cartilage over
One specific scenario has an elegant solution: when the cartilage convexity faces into the nasal cavity rather than outward. That is, the alar cartilage is mounted the wrong way round. Filling from outside will not do: the cartilage is released from skin and mucosa, completely divided at the dome and at the sesamoids, and turned over so the convexity faces forward, restoring the dome shape it should have. It is a reorientation manoeuvre, not a resection, and it uses the patient’s own cartilage rather than replacing it.
Undulating alar cartilages
This is even harder to resolve than concavity, because there is no single point to correct but an irregular surface along the cartilage. The usual solution is the alar strut graft: a cartilage plate, usually septal, sutured beneath the alar cartilage to give it a fixation plane capable of straightening it. When the cartilages are excessively rigid and will not straighten, there are two ways out: crush them to reduce rigidity, or resect them and leave the grafts in their place, rebuilding the structure from scratch.
Reorienting instead of resecting: flaps of the alar cartilage itself
The past decade points in a clear direction: use the patient’s own excess cartilage to correct its shape rather than discard it. Instead of resecting the cephalic portion of the lateral crus, it is folded on itself — a turn-in flap or lateral crural turn-in flap — with two simultaneous effects: it flattens the convexity and reinforces the remaining cartilage. Related variants exist — sliding, turn-under, turn-over — and all share the logic of preservation rhinoplasty: tissue kept is tissue you do not have to replace later. The practical advantage in thin skin is obvious: it avoids stacking grafts whose edges eventually show through.
Amorphous tip: the sequela that erases structure
It is one of the commonest alterations in secondary rhinoplasty, with a particular feature: the original tip may have been boxy, bulbous or bifid, but it was well defined. After surgery it loses its characteristic structure and becomes a surface with no recognisable shape. It is not that one specific thing was done badly: it is that there is no longer a framework.
Where an amorphous tip comes from
| Route | Responsible manoeuvre |
|---|---|
| Direct | Excessive alar resection · division or fracture of the cartilages · loss of medial support from medial crus resection · excessive dome crushing |
| Indirect | Lowering of the cartilaginous dorsum · nasal spine resection · resection of the tail of the lateral crus |
| Accidental | Cartilages dislocated while applying the dressing · displacement of a tip graft |
Two manoeuvres better avoided today
Two items from that list deserve highlighting, because they are still practised and are avoidable. Excessive dome crushing — crosshatching — weakens the cartilage unpredictably: it may look well positioned at the end and lose all definition months later, when cicatricial retraction acts on a framework with no resistance. And dislocating the cartilages while applying the dressing is purely iatrogenic: it happens at the very end, when the surgery is already well done, by pressing on a tip whose structure has just been modified.
Rebuilding an amorphous tip
- 1. ApproachOpen rhinoplasty, without question: the cartilaginous framework must be rebuilt under direct vision
- 2. InventoryIdentify what remains of each crus before planning: in secondary cases the anatomical map no longer matches the textbook
- 3. SupportRestore the support mechanisms with cartilage grafts, which by this route can be fixed and shaped with sutures far more precisely
- 4. ShapeRestore definition with domal and interdomal sutures and, if needed, a tip graft creating a new defining point
- 5. CoverageIn thin skin, interpose a camouflage layer — fascia or perichondrium — over the grafts so their edges do not show through
Loss of alar cartilage continuity
This is a rare alteration but with a recognisable picture: discontinuity of the intermediate crura producing both a boxy appearance and lack of projection. The combination is the clue, since they do not usually coincide from other causes. Treatment has two components: restore continuity with a columellar strut graft joining what is separated, and narrow the tip with intradomal and interdomal sutures. That is, first the framework is returned and only then is it shaped.
References
- 1.Arquero P. Alteraciones nasales: forma de los alares. rinoplastia.eu.
- 2.Apaydin F. Lateral crural turn-in flap in functional rhinoplasty. Arch Facial Plast Surg. 2012;14(2):93-96.
- 3.Ozmen S, Eryilmaz T, Sencan A, et al. Sliding alar cartilage (SAC) flap: a new technique for nasal tip surgery. Ann Plast Surg. 2009;63(5):480-485.
- 4.Sazgar AA. Lateral crural setback with cephalic turn-in flap. Arch Facial Plast Surg. 2010;12(6):427-430.
- 5.Gunter JP, Friedman RM. Lateral crural strut graft: technique and clinical applications in rhinoplasty. Plast Reconstr Surg. 1997;99(4):943-952.
- 6.Daniel RK, Palhazi P. Rhinoplasty: An Anatomical and Clinical Atlas. Cham: Springer; 2018.
Related specialty: Rhinoplasty