Post Market Evaluation of Clinical Safety and Performance of the Fitbone Transport and Lengthening System

The goal of this observational study is to examine and confirm the clinical performance of the Fitbone Transport and Lengthening System in adult patients (21 years and older) who require lower-limb lengthening, fracture fixation and/or treatment for previous non-healing fracture. The main questions it aims to answer are:

1. Are their any unanticipated safety issues with the product when used in a real-world setting?
2. Does the product provide the anticipated clinical benefit when used in a real-world setting?

Participants will have been selected by their physician to be treated with the Fitbone Transport and Lengthening System as part of treatment for their condition or injury. All procedures will be according to the physician's standard care practices. There are no study-specific procedures or requirements for participants in this study.

This prospective, observational clinical study is aimed at actively collecting clinical data related to the use of the Fitbone Transport and Lengthening System in a representative number of users and patients, observed in the short (\<1yr) and medium (approximately 2 years) term after implantation of the device.

The first co-primary objective of the Clinical Study is to evaluate the safety of the Fitbone Transport Nail, which will be measured in terms of percentage of participants with unplanned reoperation and/or revision surgery.

The second co-primary objective of the clinical study is to evaluate the clinical performance of the Fitbone Transport and Lengthening System as measured by percentage of participants with achievement of planned lengthening.

Eligibility Criteria:
Inclusion Criteria:

* he/she has expressed his/her willingness, to participate in the Clinical Trial by signing and dating the informed consent (as required by IRB)
* they have a limb length defect up to 8cm (without utilizing "rewind and go" option) or longer considered as suitable for correction with an intramedullary lengthening nail

Exclusion Criteria:

1. Patients with conditions that tend to retard healing such as blood supply limitations, peripheral vascular disease or evidence of inadequate vascularity
2. Patients with poor bone quality that would prevent adequate fixation of the device
3. Patients with compromised capacity for healing
4. Patients with metal allergies and sensitivities
5. Patients in which the implant would cross open, healthy epiphyseal growth plates
6. Insufficient intramedullary space which would lead to cortical weakening or vascular damage during an implantation
7. Patients with a body weight of \> 100 kg
8. No free access for proximal insertion of the intramedullary transport and lengthening nail (e.g. coxa valga)
9. No reliable exclusion of bone infection
10. Expected non-compliance, mentally ill patient or patient with clouded consciousness
11. Pregnancy
12. Patients with pre-existing nerve palsies
13. Patients with bone defects larger than 120 mm
14. Patients with Gustilo open fracture Classification Grade IIIB or IIIC fractures

as it could result in a treatment failure in the intended population.