Radial Neck-to-Humerus Transposition for Elbow Reconstruction Following Oncologic Resection of the Proximal Ulna: A Report of Two Cases

Single bone forearm reconstruction of proximal ulna metastatic lesion: A case report

INTRODUCTION AND IMPORTANCE

Colorectal cancer rarely metastasizes to the bones, and if so, metastasis usually occurs in the axial skeleton. We encountered a rare case of a metastatic lesion to the right ulna arising from colonic adenocarcinoma that was treated by resection of the proximal ulna and radial neck-to-humerus trochlea transposition to salvage the limb.

CASE PRESENTATION

A 60-year-old man previously diagnosed with colonic adenocarcinoma presented with a single bony metastatic lesion in the right proximal ulna and was referred to our clinic for assessment. After five sessions of systemic therapy, the lesion continued to grow, causing diffuse swelling and loss of elbow range of motion. Local x-rays revealed extensive destruction of the proximal ulna and soft tissue component, with subluxation of the radial head. Magnetic resonance imaging showed an extensive lesion involving the proximal half of the ulna and a large soft tissue component. After restaging, only this metastatic lesion was found. Amputation was offered to the patient for wide margin resection, but the patient refused; therefore, we performed resection of the proximal ulna, debulking of soft tissue, and radial neck-to-humerus trochlea transposition to salvage the limb.

CLINICAL DISCUSSION

Due to the rarity of the location, no clinical standard exists regarding the surgical treatment. Radial neck-to-humerus trochlea transposition is a valid surgical reconstruction technique to salvage the limb and preserve the hand function.

CONCLUSION

Radial neck-to-humerus trochlea transposition is an alternative elbow reconstruction technique after proximal ulna resection in cases where other options are not ideal or contraindicated. Long-term studies are recommended to assess different surgical options for treating and reconstructing proximal ulnar tumors.

Elbow reconstruction after excision of proximal ulna tumors: Challenges and solutions

Most malignant bone tumors are treated with surgical excision, adhering to oncologic principles, followed by reconstruction to preserve form and function whenever feasible. Primary bone tumors around the elbow are rare accounting for <1% of all skeletal tumors. They pose a reconstructive challenge, due to the complex interplay between the osseous & capsulo-ligamentous structures which is essential for elbow stability and function. Tumors affecting the proximal ulna are rare and reconstruction of the defects following these tumors is extremely challenging. Various reconstruction options like arthrodesis, autogenous bone grafts, allografts, re-implantation of sterilized tumor bone, pseudoarthrosis, and endoprosthesis have been tried with variable success. However, due to lack of standardization and the rarity of the site, surgeons are often in a dilemma to choose the correct option. This can lead to suboptimal functional outcomes and long-term failures. In this article, we reviewed the published literature on proximal ulnar tumors and noted the pros and cons of various reconstructive procedures. We have also attempted to formulate reconstruction recommendations based on the level of resection of proximal ulna.