Technique Note · For Surgeons
Incisionless rib remodeling by ultrasound-guided monocortical fracture — what the literature shows, and how I teach it.
Written for colleagues who are considering adopting the technique, or who want to understand it properly before advising a patient about it. It is not a substitute for training. Rib remodeling is the only body-contouring procedure I perform in which a technical error can be immediately life-threatening, and I would rather say that at the top of the page than bury it at the bottom.
Attribution
RIBXCAR was developed by Dr. Raúl Manzaneda Cipriani (Lima, Peru), founder of AX — Aesthetic Xpert Scientific Lab. The technique was first described in 2023 as scarless waist remodeling by ultrasound-guided monocortical fracture,[2] and the instrument it depends on — a piezotome with a modified and coated tip, now known as Manzaneda’s tool — was described the following year.[3]
I did not invent this operation. I perform it, I teach it in Asia as AX Asia Ambassador, and everything below rests on Dr. Manzaneda’s work and on the published series produced by the surgeons around him. Where I have my own emphasis, I have said so explicitly and separated it from what the literature establishes.
I mention this plainly because attribution matters in a young technique. If you adopt RIBXCAR, you are joining a body of work with named authors and a growing evidence base — including an active and useful disagreement about safety, which I have included below rather than omitted.
Principle
The operation narrows the waist by changing the angle of the lower ribs rather than by removing them. Through percutaneous punctures — no incision, no scar — a piezotome performs a corticotomy on the outer cortex only. The rib is then angulated. The periosteum is preserved, the inner cortex is left intact, and the thoracic cage retains its structural continuity.
The entire safety argument of the technique rests on that one word: monocortical. A fracture that propagates through both cortices — bicorticality — is the failure mode from which the serious complications follow.
| Element | Conventional rib resection | RIBXCAR |
|---|---|---|
| Bone | Ribs 11 and 12 removed | Ribs preserved; outer cortex scored, angle changed |
| Access | Open incision, visible scar | Percutaneous punctures, no incision |
| Instrument | Saw, rongeur, forceps | Piezotome with modified tip (bone-selective) |
| Guidance | Direct vision and palpation | Intraoperative ultrasound, real time |
| Endpoint | Bone removed | Ultrasound confirmation of angulation and cortical discontinuity |
Patient Selection
The prospective bicorticality cohort of 328 patients applied the following criteria: women aged 18–40, BMI under 30 kg/m², and visceral fat under 13%.[6] That third criterion is the one most often overlooked by surgeons new to the technique.
In that series, patients who developed bicorticality had significantly higher visceral fat than those who did not (12.7% ± 0.5 versus 8.0% ± 0.3; P < .001), and significantly longer operative times (48.9 ± 6.3 versus 43.3 ± 8.3 minutes; P = .01). BMI itself was not the discriminating variable.[6] The practical reading: a patient with an acceptable BMI but high visceral adiposity is not an easy case, and should not be scheduled as one.
Anatomy & Planning
The floating ribs (11 and 12) angulate freely because they have no anterior fixation. The false ribs (9 and 10) do not: their cartilaginous union to the costal arch resists angulation and transmits stress to that anterior fixation point. Treating them like floating ribs is a common early error.
Manzaneda and Adrianzen addressed this directly. In a 49-patient comparison, adding a false-to-floating conversion of ribs 9 and 10 produced a mean waist reduction of 17.04 cm at six months, against 8.70 cm for RIBXCAR without conversion.[5] The difference is not marginal — it is roughly double — and it tells you that the anterior fixation point, not the posterior work, is what limits the result on ribs 9 and 10.
For scale of the expected effect overall: in the 3,805-case multicentre cohort, mean angular reduction across ribs 10, 11 and 12 was 10 degrees and mean waist reduction was 11 cm, with or without associated liposuction.[1] A 220-patient single-centre series reported waist reductions of 6–11 cm at six months.[11]
Operative Sequence
Endpoint
This is the single most useful thing I can pass on to a surgeon starting out, and it is not my observation — it is Manzaneda’s, and he tested it.
In 100 consecutive patients, the audible “clack” that surgeons treat as the sign of a completed fracture was heard in 90% of cases. Intraoperative ultrasound demonstrated a monocortical fracture in 100%.[4]
In other words: in one case in ten, the fracture was already achieved and the surgeon could not hear it. A surgeon working to the sound as an endpoint will keep going in exactly those cases — which is precisely the mechanism by which a monocortical fracture becomes a bicortical one.
Define the endpoint as the ultrasound findings: angulation, loss of bone resistance, and visualised loss of cortical continuity. Not the noise.
Two views are used throughout. A longitudinal view tracks instrument position along the rib in real time. A transverse view confirms the plane — that you are where you believe you are, and that the pleura is where you believe it is. If you are not comfortable holding a probe and an instrument at once, that is the skill to acquire before the operation, not during it.
Biomechanics
A recent ex vivo study on 50 porcine ribs compared perpendicular corticotomy (point-to-point, “dots point”) with parallel scraping.[7] The findings are directly actionable:
| Measure | Perpendicular (dots point) | Parallel scraping |
|---|---|---|
| Force — monocortical | 6.67 ± 1.07 N | 14.54 ± 1.27 N (P < .001) |
| Force — bicortical | 10.0 ± 1.0 N | 17.83 ± 0.83 N (P < .001) |
| Time to bicorticality | 7.90 ± 0.71 s | 3.63 ± 0.63 s |
Read the third row carefully, because it is the one that matters clinically. With parallel scraping, the rib reaches bicorticality in roughly half the time. The margin between the fracture you want and the fracture you do not is narrower. Perpendicular corticotomy needs less force and gives you more of that margin.[7] This is an ex vivo model in porcine ribs, with the limitations that implies — but the direction of the finding is consistent with what the technique is trying to control.
Complications
I have deliberately included the data that is least flattering to the technique, because a technique note that only cites its proponents is not worth reading.
A global cross-sectional survey of board-certified plastic surgeons, covering 2,351 patient records from 2018–2024 across several rib remodeling techniques, reported an overall complication rate of 3.7%. Major complications were rare — but pneumothorax occurred in 0.17% of cases and, in that dataset, occurred only in RibXcar cases. Techniques using osteosynthesis for fracture stabilisation showed the lowest complication rate.[8]
The authors’ own conclusion is measured: performed by a well-trained surgeon with an adequate learning curve, these procedures can be considered safe. I agree with that formulation, and I would add the obvious corollary — the learning curve is not optional, and the complication it protects against is a thoracic one.
A further exchange in the literature examines piezotome-related complications specifically, with a published reply from the originating group.[9][10] If you are considering adopting the technique, read both sides.
The complications to consent for, and to be prepared to manage: pneumothorax and haemothorax; bicortical fracture with chronic pain or delayed consolidation; non-consolidation; corset-related pressure injury and hyperpigmentation; asymmetry and contour irregularity; seroma, haematoma and infection.
Emphasis
Before I performed a single aesthetic case, I spent eighteen years in thoracic surgery and lung transplantation. The chest wall and the pleural space were my daily working anatomy for most of my surgical life.
That does not make my hands better than a well-trained plastic surgeon’s on this operation. What it changes is where I put the weight when I teach it. The published major complications of RIBXCAR are thoracic complications[1][8] — and for eighteen years, recognising and managing a pneumothorax was routine work rather than an emergency I had read about.
So when I run a seminar, an unusual proportion of it is spent on: what the transverse ultrasound view is actually telling you about pleural position; how to recognise a developing pneumothorax in a sedated patient before the saturation trace does; what you need available in the room before you start; and what the first sixty seconds of management look like. Colleagues sometimes find this disproportionate for an aesthetic procedure. I think it is exactly proportionate to a procedure whose rare complication is thoracic.
Conversely, I am explicit about what I am still building: my international academic record is at its beginning, and my own series is smaller than the multicentre cohorts cited above. I would rather a colleague weigh this page on what it cites than on what it claims.
Training
I hold RIBXCAR seminars for surgeons on a regular basis in Japan, as AX Asia Ambassador. I do not teach this technique through observership, and I would gently discourage anyone from adopting it by watching a video. The parts that keep it safe — visceral fat assessment, probe handling, the ultrasound endpoint, corticotomy orientation, and what to do when it goes wrong — are the parts that do not transmit by observation.
References
Retrieved from PubMed. Where a DOI is given, it links to the source.