Final answer:
The nurse should document the bony lumps on the end joints of the fingers as Heberden nodes, which are characteristic of osteoarthritis.
Step-by-step explanation:
A client with osteoarthritis of the hands who presents with bony lumps on the end joints of the digits is most likely experiencing Heberden nodes. These nodes are bony enlargements of the distal interphalangeal (DIP) joints, and they are commonly seen in osteoarthritis, specifically in the hands. Heberden nodes are an indicative sign of the condition and differ from Bouchard nodes, which are found on the proximal interphalangeal (PIP) joints. The nurse should document the presence of Heberden nodes when noting the physical examination findings in the medical record. The other options, such as osteoblasts, Bouchard nodes, or lymph node swelling, are not the correct descriptions for lumps on the end joints of the fingers seen in osteoarthritis.