Bone metastases are common in patients with advanced cancer and frequently involve the proximal humerus, leading to severe pain and loss of shoulder function. Shoulder arthroplasty is an important surgical option for restoring limb function and relieving pain in these patients. However, elderly patients often have multiple comorbidities, and it remains unclear whether age affects surgical outcomes and prognosis after arthroplasty for proximal humeral metastases.

This retrospective observational study reviewed patients with isolated proximal humeral metastases who underwent shoulder arthroplasty at our institution. Patients were divided into elderly and younger groups based on age, and clinical outcomes were compared between the groups. Evaluated outcomes included operative characteristics, postoperative pain, limb function, complications, survival, recurrence, and quality of life.

The aim of this study is to determine whether age influences prognosis and functional recovery after shoulder arthroplasty for proximal humeral metastases, and to assess the feasibility and effectiveness of this surgical procedure in elderly patients.

This retrospective observational study reviewed patients who underwent proximal humeral hemiarthroplasty (PHH) for solitary metastatic lesions of the proximal humerus at our institution between 2013 and 2021. A total of 53 patients with histopathologically confirmed metastatic bone tumors were included in the analysis. The study population consisted of 25 males and 28 females, with ages ranging from 43 to 82 years.

Patients were divided into two groups according to age: Group A (≥65 years, n = 25) and Group B (<65 years, n = 28). All metastatic lesions were unilateral and located in the proximal one-third of the humerus without involvement of the scapula.

The most common primary malignancies included breast cancer, lung cancer, renal cell carcinoma, thyroid cancer, prostate cancer, colorectal cancer, hepatocellular carcinoma, gastric cancer, uterine cancer, and cancer of unknown primary origin. Prior resection of the primary tumor had been performed in 22 patients before presentation. Nineteen patients had comorbidities such as diabetes mellitus, hypertension, chronic gastritis, or pulmonary emphysema. Pathological fractures were present in 19 cases.

All patients underwent wide tumor excision followed by proximal humeral hemiarthroplasty using a Malawer type I resection technique. Clinical and surgical data were collected from medical records for subsequent analysis.

Inclusion Criteria:

• Patients with a single metastatic lesion in the proximal humerus, confirmed by imaging or biopsy.

Presence of pathological fracture or a severe osteolytic lesion at risk of fracture (Mirels score ≥9).

Poor response to radiotherapy according to RECIST 1.1 criteria.

Persistent severe shoulder pain or significant loss of shoulder function.

Estimated life expectancy >3 months at the time of surgery..

Exclusion Criteria:

• Patients with multiple bone metastases involving two or more skeletal sites.

Metastatic lesions affecting the scapula, axillary nerve, or brachial plexus.

Death during the perioperative period.

Presence of three or more significant comorbidities, such as uncontrolled diabetes, severe cardiopulmonary disease, or chronic renal failure.

Loss to follow-up within 3 months after surgery.

This study included adult patients with solitary proximal humeral metastases who underwent proximal humeral hemiarthroplasty at our institution between 2013 and 2021. Both male and female patients were eligible. Patients were divided into two groups based on age (≥65 years and <65 years) to compare surgical outcomes, functional recovery, complications, and survival. All patients had confirmed metastatic bone tumors, with lesions localized to the proximal humerus and without involvement of the scapula or axillary nerve. Patients with multiple bone metastases or severe comorbidities were excluded.

Individual participant data will not be shared due to patient privacy concerns and ethical restrictions. The data include sensitive medical information collected from hospital records, and sharing such data could risk identification of patients.