An observational study in Limb Fracture and Bone Loss, sponsored by AO Innovation Translation Center. Recruiting at 21 sites in 14 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-08-29.
Sponsored by AO Innovation Translation Center · Observational
Long bone defect (LBD) is defined as a focalized loss of bone tissue in any long bone of the upper or lower extremity. Long bone defects are a complex problem, that may arise as a complication of many different pathologies, such as trauma, tumors or infection. Whereas post-traumatic defects are the largest group.
Reports estimate that there are almost 4 million bone grafting procedures worldwide per year. However, limb reconstruction in the context of a bony defect is challenging and up to date there is little evidence and treatment recommendations.
In a multi-national approach, the aim of this project is to set up an international, multicenter registry to gather information and details on prevalence or incidence, current treatments, complications and outcome.
The purpose of this project is to set up an international, multicenter registry of patient presenting with defects in long bones. Up to date, treatment remains challenging with little evidenced-based recommendations.
For this purpose, any patient who presents at a study center with a bone defect of the defined expansion of any long bone is eligible for inclusion. Over a 3-year period as many patients as possible are included from the participating sites, at least 600 patients should be included in the registry. Details on any surgical intervention that is used to treat a bone defect will be recorded. Further patient-related and other pre-defined outcome measures will be collected.
There is no formal hypothesis to this registry, hence it will help to identify prevalence and underlying etiologies, evaluate treatment strategies, and highlight possible challenges and complications - and will so help to gather clinical evidence to provide better treatment for patients suffering from a long bone defect.
661 studies on the registry are indexed under Bone Diseases, Metabolic; 93 are open to participants now.
This study's planned enrollment of 600 is above the median of 80 across 138 observational studies indexed under Bone Diseases, Metabolic.
Browse Bone Diseases, Metabolic studies →AO Innovation Translation Center is the lead sponsor of 32 studies on the registry; 11 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients with a traumatic bone defect in any long bone
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.
Post traumatic bone defect > 2 cm either
obtained, i.e.:
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.
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.
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.
Any treatment that is used for a defect of any long bone. All treatments are based on individual clinician's judgement and the patient characteristics. The registry does not dictate any specific treatment.
Baseline characteristics
Demographics, medical history, comorbidity
Time frame: Pre-operative
Bone defect details
* Affected bone * Localization: Proximal 1/3rd, middle 3rd, distal 1/3rd(for any bone) * Size (categorization according Karger classification; definition: a bone defect should be at least 2 cm (Karger Type II)) Type II: 2-5 cm Type III: 5-10 cm Type IV: \> 10 cm
Time frame: Pre-operative and/or intraoperative
Trauma assessment
* Injury Severity Score (ISS): Grading for each item (points): No injury (0), Minor (1), Moderate (4), Serious (9), Severe (16), Critical (25), Unsurvivable (75) * Assessment: * Head and neck worst injury * Face worst injury * Chest worst injury * Abdomen worst injury * Extremity (including pelvis) worst injury * External worst injury * Gustilo \& Anderson classification for open fractures * Type I * Type II * Type IIIA * Type IIIB * Type IIIC * Tscherne classification for closed fracture and soft-tissue injuries * Grade 0 * Grade 1 * Grade 2 * Grade 3
Time frame: Pre-operative and/or intraoperative
evaluate the bone defect in the context of previous interventions
Number of previous interventions: \<2, \<4, \>4
Time frame: Intraoperative
Surgical details & Intraoperative findings 1
* Procedure type: * One stage * Staged (e.g. Masquelet technique / distraction osteogenesis / bone transport) * Ilizarov * Bone quality (good, fair, poor) by surgeon's discretion * Soft tissue and vascularity (good, fair, poor) by surgeon's discretion * Contamination (yes/no) Specification: * Metal from a bullet * Metal from a pole * Other Metal * Wood * Soil * Others * Surgical time (min) * Stabilization technique: Internal device (extra- or intramedullary) / External device (For both, drop down menu will be used)
Time frame: Intraoperative
Surgical details & Intraoperative findings 2
* Bone grafting * Autografts * Allograft(s) * Other synthetics * If applicable - time to harvest graft (in minutes) * Graft enhancement yes / no * Demineralized bone matrix (DBM) * Bone morphogenetic protein (BMP) * Stem cells * Platelet rich plasma (PRP) * Other * Soft-tissue / vascular / microsurgical procedure yes / no * Skin graft * Local flap * Free flap * Additional treatment * Systemic antibiotic treatment yes / no * Local antibiotic treatment yes / no * Post-operative use of a negative pressure dressings (NPWT) or vacuum-assisted closure (VAC) system yes / no
Time frame: Intraoperative
Functional Outcome
\- Assessment of limb function and loss of length * Definition: anatomic shortening of the limb in comparison to the contralateral side * Assessment in cm * Any orthotic used to equalize leg length
Time frame: 6 months follow-up / 12 months follow-up and/or 6 months after bone union (max 12 months)
Patient related outcome / Quality of life 1
Patient-Reported Outcomes Measurement Information System (PROMIS) * Physical function: This item measures self-reported capability rather than actual performance. It includes the functioning of lower extremities (walking or mobility) as well as instrumental activities of daily living, such as running errands. We will use the short form 10b. * Physical function, upper extremity: This item measures activities that require use of the upper extremity including shoulder, arm, and hand activities. Examples include writing, using buttons, or opening containers. We will use the short form 7. * Pain Interference: This item assesses self-reported consequences of pain on relevant aspects of one's life. This includes the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. We will use the short form 8a. Short forms will be used in all sites possible (i.e. where the translation is available).
Time frame: Screening / 6 months follow-up / 12 months follow-up and/or 6 months after bone union (max 18 months)
Patient related outcome / Quality of life 2
EQ-5D-3L assessment (Five items, 3-point categorical scale) The EQ-5D-3L descriptive system comprises the following five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems, some problems, and extreme problems. o The EQ VAS records the patient's self-rated health on a vertical visual analogue scale where the endpoints are labelled 'Best imaginable health state' and 'Worst imaginable health state'. The VAS can be used as a quantitative measure of health outcome that reflects the patient's own judgement.
Time frame: Screening / 6 months follow-up / 12 months follow-up and/or 6 months after bone union (max 18 months)
Radiological Outcome
Pre-operative/intraoperative * Deformity parameters (if applicable) * Nonunion classification: Hypertrophic, Oligotrophic, Atrophic Follow-up visits * Bone healing (based on the treating physician's judgement): Not healed / Partially healed / Mostly healed / Healed * Evaluation of the expansion of the bone defect: bone defect size * Time to healing: Date when full healing is achieved (to be calculated days from index surgery)
Time frame: Screening / / Intraoperative / 6 months follow-up / 12 months follow-up and/or 6 months after bone union (max 18 months)
Not enrolling at this site — choose another above.
Not enrolling at this site — choose another above.
Plan to share: Undecided
No publications or documents are linked to this record.
Started Jul 2024 (actual). Primary completion is estimated for May 2028, 46 months after the start.
Of 51 non-industry observational studies under Bone Diseases, Metabolic, half reached primary completion within 60 months of starting (the median), counting those still running; a quarter within 19. This study's planned 46 months is below that.
Counting every sponsor, half of 52 studies reached it within 60 months; a quarter within 19.
How these figures are worked out, and which studies are left out of them.
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