The enrolment phase was halted prematurely due to logistic issues ( SARS-CoV2 pandemic). All patients enrolled completed the follow-up visits according to the study protocol.

Multi-center, international, prospective, open-label, single-arm, first-in-human clinical investigation. The Patients enrolled in this clinical investigation will undergo a scheduled surgery for the treatment of long bone defects up to 6 cm using GreenBone Implant. After the surgery, the Patients will be monitored at pre-scheduled visits up to 12 months. Adverse events, pain, quality of life and functional parameters, as well as X-ray and CT scan, will be evaluated at scheduled follow-up visits. An independent Data Safety Monitoring Board (DSMB) will review the safety reports at regular intervals and Serious Adverse Events (SAE) as soon as reported, to protect Patients participating in the study. The initial phase of the study contemplates the treatment of bone defects up to 3 cm. An adaptive interim analysis will be performed when the first 7 Patients will have completed the 6-month follow-up visit. The DSMB will review the results of the interim analysis with respect to the primary endpoint (safety), and provide one of the following recommendations to the Sponsor: a) to stop the study for unacceptable frequency and severity of adverse events or b) to continue the study up to 25 Patients recruited and to include at least 5 Patients with a longer bone defect (> 3 cm up to 6 cm).

This is a pre-market multi-centre, international, open label, single-arm, study to evaluate the safety and performance of a Class III medical device (GreenBone Implant) for the treatment of long bone defect. Bone defects can result from malformation, high-energy traumatic events, bone resection due to different pathologies such as tumors or infections, or from the treatment of complex non-unions. Current treatment of bone defects usually implies the use of bone grafts and/or biocompatible materials, to create a scaffold that bridges the defect. Autograft and Allograft are the treatments most currently used for large bone loss, but both treatments have significant disadvantages. These types of treatment carry the risk of transferring disease from animals and/or humans to the patient; there is also a risk of host local allergic reaction. Bone substitutes are devoid of the above risks and therefore they could be used alternatively to xenografts and allografts. GreenBone is a ceramic resorbable bone scaffold that has very similar structure to bone. It can be produced in large quantities, shaped easily and sterilised without losing its properties. Consequently, it is an ideal substitute that could be used to fill bone defects. This study will assess the safety of using GreenBone treatment of long bone defects up to 6 cm. Moreover it will assess its capacity of promoting new bone formation. The investigators will recruit 25 patients with long bone defect and instead of bovine xenograft we will use the GreenBone implant for the long bone reconstruction. Patients will be followed up for 12 months in total.

Inclusion Criteria:

1. Male or female Patients.
2. Patients aged ≥ 18 and ≤ 65 years old.
3. Patients requiring long bone defect reconstructions up to 3 cm, resulting from high-energy traumatic events, or from the treatment of complex bone non-unions in the extremities (arms and legs), or patients undergoing the second stage of the Masquelet technique.
4. Patients understanding the nature of the study and providing their informed consent to participation.
5. Patients willing and able to attend the follow-up visits and procedures foreseen by study protocol.

Please note: after interim analysis review by the DSMB, inclusion criteria n. 3 will be modified as follows (all Investigators will be notified by the Sponsor, and adequate training by Clinical Research Associate-CRA will be conducted):

Change of inclusion criteria n. 3: Patients requiring long bone defect reconstructions longer than 3 cm and up to 6 cm, resulting from high-energy traumatic events, or from the treatment of complex bone non-unions in the extremities (arms and legs), or patients undergoing the second stage of the Masquelet technique.

Exclusion Criteria:

1. Patients with bone infection at the time of enrolment.
2. Patients with bone malignant tumor(s) at the time of enrolment.
3. Patients who have been treated with chemotherapy or radiotherapy within 12 months before the enrolment.
4. Patients with concomitant infectious systemic diseases at the time of enrolment.
5. Patients with known inflammatory systemic diseases at the time of enrolment.
6. Patients with concomitant myeloproliferative disorders at the time of enrolment.
7. Patients currently treated with systemic immunosuppressive agents, excluding steroids.
8. Patients with active autoimmune disease.
9. Patients with a pre-existing calcium metabolism disorder (i.e. hypercalcemia).
10. Known hyperthyroidism or autonomous thyroid adenoma.
11. Patients with coagulopathy or bleeding disorders.
12. Patients who are not allowed to undergo the study procedures involving imaging (X-rays, CT scan) based on Investigator's judgement.
13. Patients with known or suspected allergy or hypersensitivity to the GreenBone Implant components.
14. Patients who are participating or have participated in other clinical studies within the 30 days before the study enrolment.
15. Patients identified by the Investigator to have intra-operative findings that may preclude conduct of study procedure.
16. Patients with occurrence of major intra-operative complications that require resuscitation or deviation from the planned surgical procedure.
17. Women who are pregnant or breast-feeding or who wish to become pregnant during the period of the clinical investigation and for three months later.
18. Female Patients of childbearing age (less than 24 months after the last menstrual cycle) who do not use adequate contraception.

Only patients treated for bone defect repair were included in the analysis population (16 participants).

1 year

An adverse event (AE) is defined as any untoward medical occurrence, unintended disease or injury or any untoward clinical signs (including an abnormal laboratory finding) in subjects, users or other persons whether or not related to the investigational medical device.