An observational study in Chest Wall Deformity and Prominent Lower Rib Cage, sponsored by Research Inc. Recruiting at 1 site in Colombia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-10.
Sponsored by Research Inc · Observational
This prospective single-group study will evaluate anterior aesthetic rib cage remodeling with osteosynthesis (ARCO) in adults with anteroinferior rib prominence or deformity. The procedure modifies and stabilizes ribs 6 through 8. Inferior rib cage perimeter, CT findings, spirometry, intraoperative respiratory variables, BODY-Q Chest scores, and complications will be assessed through 12 months. The primary outcomes are one-year perimeter change and major procedure-related complications.
Participants who meet standardized ARCO eligibility criteria will undergo preoperative chest CT, spirometry, anthropometry, photography, and BODY-Q assessment. During surgery, controlled greenstick remodeling of the selected anterior ribs will be followed by plate osteosynthesis. Peak inspiratory pressure and pulmonary compliance will be recorded before remodeling, during the maneuver, and after fixation, and thoracic ultrasound will assess pleural integrity. Postoperative CT will evaluate angulation, union, and hardware position; spirometry will assess pulmonary function; and standardized perimeter and BODY-Q measurements will assess aesthetic effectiveness. Complications will be actively collected through month 12.
Research Inc is the lead sponsor of 24 studies on the registry; 22 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Adults seeking correction of anteroinferior rib cage prominence or deformity who meet the standardized ARCO operative criteria.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants undergo anterior aesthetic rib cage remodeling with controlled greenstick rib modification and plate osteosynthesis, followed by standardized 12-month assessments.
Procedure: Anterior Aesthetic Rib Cage Remodeling With Osteosynthesis · Diagnostic Test: Chest CT and Spirometry Follow-up
Through small inframammary incisions, the lower borders of ribs 6, 7, and 8 are identified. The external cortical layer is cut using a piezoelectric device, controlled greenstick remodeling is performed, and each treated rib is stabilized with a contoured titanium plate and screws. The final surgical manual will specify treated ribs, target angle, fixation system, and verification steps. Linked arm/group(s): ARCO Procedure.
CT will assess rib angle, fixation, union, and thoracic complications. Spirometry will record FVC, FEV1, FEV1/FVC, peak expiratory flow, and FEF25-75 using standardized quality criteria. Linked arm/group(s): ARCO Procedure.
Change in Inferior Rib Cage Perimeter at the Eighth-Rib Level
Circumference in centimeters will be measured using a standardized horizontal landmark at end-expiration. Three measurements will be averaged. Change is the 12-month value minus baseline; a negative value indicates perimeter reduction.
Time frame: Baseline and postoperative month 12. 12 months
Incidence of Major ARCO-Related Complications
Proportion of participants with pneumothorax requiring drainage, hemothorax, fixation failure requiring intervention, symptomatic nonunion/malunion, deep infection, respiratory deterioration requiring treatment, unplanned reoperation, or another serious procedure-related event.
Time frame: From surgery through postoperative month 12. 12 months
Change in Spirometric Pulmonary Function FVC
Change in FVC from baseline. Values will be reported in liters, ratios, and percent predicted as appropriate.
Time frame: Baseline, postoperative week 6, postoperative month 3, and postoperative month 12. 12 months
CT-Confirmed Structural Stability
Proportion of treated ribs with maintained planned angulation, stable plate and screw position, evidence of union, and no clinically significant loss of correction, nonunion, malunion, or hardware migration.
Time frame: Postoperative week 6, postoperative month 3, and postoperative month 12 if the final radiation protocol includes the 12-month CT. 12 months
Change in BODY-Q Chest Satisfaction Score
Rasch-transformed 0-to-100 BODY-Q Chest score; higher values indicate greater satisfaction with chest appearance.
Time frame: Baseline, postoperative day 7, postoperative month 3, and postoperative month 12. 12 months
Change in Intraoperative Peak Inspiratory pressure
Peak inspiratory pressure will be recorded at standardized ventilator settings immediately before rib remodeling, during open greenstick modification, and after definitive fixation.
Time frame: Intraoperative: before rib remodeling, during remodeling, and after fixation during the index procedure. 1 day
Change in Intraoperative Pulmonary Compliance
dynamic pulmonary compliance will be recorded at standardized ventilator settings immediately before rib remodeling, during open greenstick modification, and after definitive fixation.
Time frame: Intraoperative: before rib remodeling, during remodeling, and after fixation during the index procedure. 1 day
Change in Spirometric Pulmonary Function FEV1
Change in FEV1from baseline. Values will be reported in liters, ratios, and percent predicted as appropriate.
Time frame: Baseline, postoperative week 6, postoperative month 3, and postoperative month 12. 12 months
Change in Spirometric Pulmonary Function FEV1/FVC
Change in FEV1/FVC from baseline. Values will be reported in liters, ratios, and percent predicted as appropriate.
Time frame: Baseline, postoperative week 6, postoperative month 3, and postoperative month 12. 12 months
Change in Spirometric Pulmonary Function peak expiratory flow
Change in peak expiratory flow from baseline. Values will be reported in liters, ratios, and percent predicted as appropriate.
Time frame: Baseline, postoperative week 6, postoperative month 3, and postoperative month 12. 12 months
Change in Spirometric Pulmonary Function FEF25-75
Change in FEF25-75 from baseline. Values will be reported in liters, ratios, and percent predicted as appropriate.
Time frame: Baseline, postoperative week 6, postoperative month 3, and postoperative month 12. 12 months
Plan to share: No — not contempled in the patient informed consent
Ran from Jan 2025 to primary completion in May 2026, 16 months.
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