What can the surgeon do to reduce the risk of junction breakage in modular revision stems?

Modular revision stems are very common in hip arthroplasty, but junction fracture remains a known failure mechanism. A review of the literature with description of cases with junction breakage of modular revision stems showed that in all 24 analyzed cases, there was a common finding: the combination of an effective osteointegration of the distal component and missing medial bone support of the proximal component. The result was a bending stress point of the stem construction in the region of the junction. A technique using the combination of short distal component and longer proximal components may alter this stress pattern, allow proximal implant support, and reduce the risk of junction fracture. Moreover, filling of gaps between the modular component and the medial region of the femoral calcar in endofemoral implantation, a double osteotomy in significant bowed femurs, and treating medial bone defects with structural allografts additionally can reduce the risk of junction breakage.