Massive prostheses are the standard treatment for extensive bone loss, whether caused by cancer or other factors (complex fractures, multiple revisions, infections).

The emergence of modular systems such as the Pantheon range provides rapid restoration of function and precise intraoperative adaptation to anatomical constraints and specific bone loss characteristics.

The Pantheon range also offers an innovative intramedullary ring system that promotes osseointegration and potentially long-term mechanical stability of implants.

However, few studies have evaluated its clinical efficacy. In this context, a prospective cohort study is warranted in order to obtain robust data on implant survival, patient quality of life and predictors of medium- and long-term complications.

The IMPULSION study is an observational study. The primary objective is to evaluate prosthesis survival within 5 years post-operatively.

The secondary objectives are: to evaluate functional outcomes, quality of life, the occurrence of complications, and the osseointegration of the intramedullary ring.

Patients are included during the consultation to plan the surgery. Following surgery, the patient is followed up at 1 year, 2 years and 5 years post-operatively.

Inclusion Criteria:

• Patients aged 15 years or older at the time of inclusion
• Surgery scheduled at one of the participating centres with an Adler implant from the list below:

Implants from the Pantheon prosthesis:

Proximal Femur Recontruction (PFR) Distal Femur Reconstruction (DFR) Proximal Tibia Reconstruction (PTR) Total Femur Reconstruction (TFR) Hybrid connector implants Custom-made implants

• Follow-up scheduled at one of the participating centres for the duration of the study
• Patient who has been informed about the study and does not object to participating In the case of minor patients, the patient's parents will also be informed, and their non-objection will be sought.
• Patient affiliated with a Social Security scheme in France.

Exclusion Criteria:

• Patient or parent of a minor patient who objects to participation in the study and data collection.
• Patient deprived of liberty or under legal protection (guardianship or curatorship)

The population concerns patients with massive bone loss, because of oncological or non-oncological issue. Patients have massive prosthetic reconstruction using the Pantheon prosthesis from Adler Laboratories. The prostheses are:

• Proximal Femur Recontruction (PFR)
• Distal Femur Reconstruction (DFR)
• Proximal Tibia Reconstruction (PTR)
• Total Femur Reconstruction (TFR)
• Custom implants Minors aged 15 and over may be included in the study, with no maximum age limit. Patient who has been informed about the study and doesn't object to participating.