Intramedullary humeral replacement: an evolving design

Using 3D Printing Technology to Design Split-Piece Sleeve Prosthesis in the Revision Surgery of Tumor-Type Total Elbow Prosthetic Fractures: A Case Report

BACKGROUND

Revision of tumor-type prosthetic fractures is very challenging in clinical work. Traditional repair methods may not be able to meet the needs of complex cases or cause greater bone damage. Therefore, more effective and reliable solutions need to be found.

CASE PRESENTATION

This study presents a novel revision technique for managing fractures of tumor-type total elbow prostheses. A 57-year-old female patient was diagnosed with a left distal humeral bone tumor accompanied by pathological fracture and underwent customized tumor-type total elbow prosthesis arthroplasty. After 5 years, she experienced pain and encountered difficulty in flexing the left elbow while lifting heavy objects. The X-ray examination revealed a fracture of the distal humeral prosthesis. As a response, the elbow joint was initially explored, and the damaged component of the prosthesis was extracted. Subsequently, we utilized 3D printing technology to design a split-piece sleeve prosthesis and effectively restored the fractured left distal humerus implant. During the 2-year follow-up, The X-ray demonstrated satisfactory positioning of the prosthesis, which remained securely affixed without any indications of loosening. The Mayo Elbow Performance Score (MEPS) reached 80 points, the Musculoskeletal Tumor Society (MSTS) attained a score of 28 points, and the range of motion of the elbow was measured between 25° and 110°, revealing favorable functional outcomes.

CONCLUSION

The utilization of a 3D printed split-piece sleeve prosthesis presents a viable clinical treatment strategy for addressing fractures in tumor-type elbow prostheses.

Endoprosthetic Reconstruction of the Upper Extremity in Oncologic Surgery

In 1943, Austin Moore successfully reconstructed a proximal femur using a Vitallium endoprosthesis. This marked the first successful alternative to amputation in oncologic surgery. However, it was not until the introduction of high-resolution axial imaging and improved chemotherapeutics that the feasibility of limb salvage began to improve. Today, limb salvage surgery can be used to treat most oncologic conditions of the extremities, the most popular reconstruction option being endoprostheses. Megaprostheses use has expanded to nononcologic indications with severe bone loss, including infections, revision arthroplasty, and severe periarticular trauma and its sequelae. The proximal humerus and scapula are challenging for reconstruction, given the complex anatomy of the brachial plexus, the accompanying vascular structures, and the dynamic stabilizers of the relatively nonstable glenohumeral joint. The midhumerus is difficult because of the close location of the radial nerve, whereas the distal humerus is challenging because of the proximity of the brachial artery and its bifurcation, radial, ulnar, and median nerves, and lack of soft-tissue coverage. Despite these challenges, this review demonstrates that many series show excellent mid- to long-term results for pain relief and function restoration after megaprosthetic reconstruction of the scapula and humerus after bone resections for oncologic and nononcologic reasons.

Megaprosthesis versus Allograft Prosthesis Composite for massive skeletal defects

Massive skeletal defects are encountered in the setting of tumors necessitating excision, failed total hip arthroplasty with periprosthetic bone loss, periprosthetic fracture, complex trauma, multiple failed osteosynthesis and infection. Reconstruction of the segmental defects poses a tremendous challenge to the orthopaedic surgeons. The goal of osseous reconstruction of these defects is to restore the bone length and function. Currently the most commonly employed methods for reconstruction are either a megaprosthesis or an Allograft Prosthesis Composite (APC). Megaprosthesis, initially created for the treatment in neoplastic pathologies are being used for the non-neoplastic pathologies as well. The longevity of these implants is an issue as majority of the patients receiving them are the survivors of oncologic issue or elderly population, both in which the life expectancy is limited. However, the early complications like instability, infection, prosthetic breakage and fixation failure have been extensively reported in several literatures. Moreover, the megaprostheses are non-biological options preventing secure fixation of the soft tissue around the implant. The Allograft Prosthesis Composites were introduced to overcome the complications of megaprosthesis. APC is made of a revision-type prosthesis cemented into the skeletal allograft to which the remaining soft tissue sleeve can be biologically fixed. APCs are preferred in young and low risk patients. Though the incidence of instability is relatively low with the composites as compared to the megaprosthesis, apart from infection, the newer complications pertaining to APCs are inevitable that includes non-union, allograft resorption, periprosthetic fracture and potential risk of disease transmission. The current review aims to give an overview on the treatment outcomes, complications and survival of both the megaprostheses and APCs at different anatomic sites in both the upper and lower limbs.