Titanium vs. carbon fiber-reinforced intramedullary nailing for humeral bone tumors

Multiple techniques have been described to treat humeral diaphyseal bone tumors requiring curettage or excision. Recent studies have suggested that carbon fiber-reinforced polyetheretherketone (CFR-PEEK) intramedullary nails (IMNs) may be preferable to titanium IMNs for patients with musculoskeletal tumors due to CFR-PEEK's high tensile strength, radiolucency, a modulus of elasticity closer to native bone, and improved postoperative surveillance/radiation dosing. In this study, we describe the rate of fixation failure for both CFR-PEEK and titanium humeral IMNs when used for humeral diaphyseal bone tumors requiring curettage or excision.

This was a single-institution retrospective cohort study including 81 patients (27 CFR-PEEK and 54 titanium) treated for a humeral diaphyseal bone tumor using an IMN ± methylmethacrylate between January 2017 and December 2022. Primary outcome was revision surgery due to soft tissue complications, nonunions, structural complications such as periprosthetic fracture or IMN breakage, periprosthetic infection, tumor progression, and implant failure due to rejection or fatigue.

No failures were observed in either patients treated with titanium nails or patients treated with CFR-PEEK not requiring curettage. Fixation failure due to implant failure was observed in 2 cases-at 214 days and 469 days after surgery-where CFR-PEEK IMN was used for stabilization after a wide segmental resection for oncologic control with a cement spacer reconstruction. In both cases, the resection was larger than 6 cm, the remaining distal humerus was less than 5 cm, and failures occurred at the interface of the residual bone and spacer. Both patients were revised using a titanium distal posterolateral humeral plate fixed with screws and cables without any subsequent complications. One additional CFR-PEEK IMN required revision surgery after 744 days due to progression of the tumor and subsequent nonunion. One revision surgery was observed after 63 days for the titanium IMN because of nonunion and tumor progression.

Humeral diaphyseal bone tumors requiring large segmental resection with small residual bone and a large cement spacer may fail via tension due to bending forces at the distal portion. In this clinical scenario, the use of larger-diameter CFR-PEEK IMNs may be indicated when available. In the interim, use of intercalary allografts instead of cement spacers, additional fixation with a titanium plate distally, or the use of a titanium nail when using a cement spacer may be considered.