The aim of the study is to describe, through a minimum follow-up of 18 months, the quality of life of patients undergoing salvage surgery of lower limb for musculoskeletal tumors and to identify possible prognostic factor correlated.

Quality of life will be evaluated with Bt-DUX (Bt=bone tumor)

Musculoskeletal cancers are extremely rare, accounting for approximately 0.2% of all cancers, 14% are bone sarcomas, which occur more frequently in children and adolescents. The most frequent location is at the metaphyseal level of the femur (42%) and tibia (19%).

Surgery and chemotherapy treatments have significantly increased survival rates for patients with bone tumor. Early rehabilitation of these patients after surgery is to promote recovery as early as possible with maximum autonomy. In literature, data about the association between the early functional recovery and quality of life are few. Long-term studies about the quality of life of these patients are so necessary. The quality of life is measured with several scale that included a set of non-specific domains for bone tumor patients. For this reason, a specific assessment scale was introduced and validated in 2013 to measure the quality of life of patients with bone cancer of the lower limbs, the Bt-DUX scale.

In 2019 the Bt-DUX scale was validated in Italian.

Considering the rarity of the disease, and verified that the number of patients treated in 2019 and 2020, is 30 and 32, respectively, the investigators estimate to enroll from January 2019 to June 2023 a number of patients equal to 100, considering a rejection rate of 10%.

Patient characteristics and scale values will be summarized using descriptive statistics (absolute frequencies and percentages for categorical variables, mean and standard deviation or median and interquartile range for continuous variables).

The variables collected will be: age, sex, diagnosis, type of surgery, site of tumour, complication (infection, relapses, metastasis), TESS (Toronto Extremity Salvage Score) (at 3 and 6 months), knee or hip flexion (at 3 and 6 months), quadriceps or hip abductor strength (at 3 and 6 months) and time up and go (at 3 and 6 months).

The relationship of patient characteristics with functional outcomes and quality of life will be investigated using multiple regression models, while the correlation between measures of functional recovery will be analyzed using Pearson's or Spearman's correlation coefficient, depending on the distribution of the variables considered.

The aim of the study is to describe the quality of life of patients undergoing salvage surgery of the lower limb for musculoskeletal tumors with a long follow-up and to investigate the association with early functional recovery.

Inclusion Criteria:

• Patients 12 years of age or older with musculoskeletal cancer undergoing lower extremity salvage surgery

Exclusion Criteria:

• patients undergoing amputation
• patients with difficulties in understanding the Italian language

Patients with musculoskeletal tumor of the lower limbs who underwent salvage surgery at the "SC Clinica Ortopedica e Traumatologia III" of the Rizzoli Orthopedic Institute from January 2019 to June 2023 and will be followed up in the "SC Osteoncology, bone and soft tissues sarcomas and innovative therapies" of the same Institute for chemotherapy and physiotherapy treatment.