(P 93) INTERCALARY COMPRESSIVE OSSEOINTEGRATION OF DIAPHYSEAL TUMORS: A MULTI-INSTITUTIONAL CASE SERIES

Objective: There is no consensus on treatment for diaphyseal reconstruction after significant bone loss. While intercalary allografts restore bone stock, they are associated with longer healing times, infection, and allograft fracture. Intercalary endoprostheses, by contrast, may offer immediate stability and early mobilization. We present a multi-institutional case series evaluating outcomes following reconstruction with Compress® Compliant Pre-Stress (CPS) spindle paired with the Orthopedic Salvage System for intercalary endoprostheses, with one spindle placed proximally and one distally. Our goal was to assess revision rates.

Methods: A retrospective review of 13 patients who underwent diaphyseal tumor resection and reconstruction using an intercalary endoprostheses between 2007-2024 at three tertiary sarcoma centers was performed. Median age was 28 years; median follow-up was 11 months. Diagnoses included primary bone sarcomas (n=11), primary intraosseous hemangioma (n=1), and metastatic melanoma (n=1). Chemotherapy was administered to 85% (n=11) and radiation therapy to 23% (n=3). Flap closure was required in 62% (n=8) of cases.

Results: There were no cases of periprosthetic infection. Five patients (39%) required reoperation: two for ingrowth failure (one converted to megaprosthesis), two for Morse taper dissociation (one revised with soft tissue reconstruction, one with a custom lap joint), and one for disease progression (amputation). There were no periprosthetic fractures.

Conclusion: Spindle complications following Compress® intercalary reconstruction were similar to those seen in megaprosthetic reconstructions. These findings support its use as a promising option for diaphyseal reconstruction; however, larger cohort studies are needed given the rarity of these reconstructions to better assess long-term outcomes and implant durability.

Patient demographics, tumor characteristics, treatment details, and outcomes following Intercalary reconstruction