Radical cystectomy (RC) with ileal urinary diversion (UD) is a standard treatment for muscle-invasive bladder cancer. However, emerging evidence indicates that this procedure may significantly impact bone health. Patients with UDs have a 21-48% higher risk of experiencing a fragility fracture compared to the general population. The underlying mechanisms are not entirely understood, but one prevailing hypothesis implicates substantial bone mineral density (BMD) loss due to the metabolic changes induced by UD, particularly driven by metabolic acidosis.

Dual-energy X-ray absorptiometry (DXA) remains the gold standard for measuring BMD and provides an indirect assessment of fracture risk. However, the trabecular bone score (TBS), a non-invasive imaging technique that evaluates bone microarchitecture, offers additional insights into bone quality that are independent of BMD and enhances the understanding of bone strength and fracture resistance. Furthermore, the use of tools such as the FRAX® (Fracture Risk Assessment Tool) helps in identifying patients at higher risk of osteoporotic fractures by estimating the 10-year probability of major fractures (MOF) (spine, forearm, hip, or shoulder) and hip fractures (HIP) based on various clinical risk factors. The predictive accuracy of FRAX® can be further refined by incorporating femoral neck BMD and adjusting for TBS.

Osteoporosis in men is a frequently underdiagnosed and undertreated condition. This underdiagnosis is also evident in patients with UDs. This study aims to evaluate the prevalence of bone alterations in men post-RC, employing both BMD and TBS measurements. Additionally, it seeks to identify key risk factors and critically assess the utility of FRAX® as a screening tool for pinpointing patients at elevated fracture risk.

To the best of the investigator's knowledge it will be the first study assessing the bone health after RC evaluating BMD, TBS and the fracture risk using the FRAX algorithm.

Inclusion Criteria:

• All patients who understand, agree to participate and sign the informed consent.
• Males older than 50 years old.
• Patients undergoing radical cystectomy with ileal conduit or neobladder.
• Time over one year after radical cystectomy.

Exclusion Criteria:

• Female gender.
• Males below 50 years old.
• Radical cystectomy performed less than one year before.
• Radical cystectomy with cutaneous ureterostomy.
• Patients diagnosed with primary hyperparathyroidism.
• Patients receiving treatments that could influence bone metabolism, such as antiresorptive agents (including bisphosphonates or denosumab), chronic corticosteroids, androgen deprivation therapy for prostate cancer. Patients receiving treatment with Vitamin D were not excluded.
• Patients previously diagnosed with osteoporosis.
• Patients with a history of hemodialysis or renal transplantation.
• Patients receiving systemic cancer therapies for bladder tumor progression or other malignancies.
• Any patient who does not agree to participate or does not sign the informed consent

Males who underwent radical cystectomy with ileal urinary diversion (ileal conduit or neobladder).