Implant Reconstruction of the Humeral Diaphysis: Total Humerus Prosthesis

Abstract

The humerus is a relatively common site for primary bone tumour or metastatic bone disease. In our database of 4870 primary bone tumours and 3916 metastatic bone tumours, the humerus accounted for 9% (n = 448) and 14% (n = 543) of cases. However, of these 991 humeral tumours, a total humerus endoprosthetic replacement (THEPR) was only undertaken in 44 cases (4%). The indications were predominantly for primary bone tumours, with only three cases (7%) being undertaken for metastatic bone disease. Undertaking a THEPR, therefore, is an unusual operation for a surgeon and even in a large tertiary referral primary bone tumour unit; it may only be indicated once or twice per year. The tumour rarely involves 100% of the humerus; however, a THEPR may be chosen over a sub-total humeral replacement or biological replacement due to:

• 1. Poor fixation available in a small distal or proximal section of bone unaffected by the tumour.

• 2. The presence of a fracture or other factor that means the delay in manufacture of a custom-made prosthesis would be a detriment to the patient.

As all the supporting ligaments and muscle attachments of the humerus will be removed following en bloc resection with a tumour dependent wide margin, the primary aims of the operation are to provide stability at the shoulder and preserve good function to the elbow and hand. The approach and knowledge of, particularly, neurovascular anatomy is essential to provide the best outcome. We present our experience of THEPRs, illustrating a typical case of a 67-year-old female presenting with a minimally displaced pathological fracture of the humerus through a central chondrosarcoma.