Background and purpose Revision surgery for periprosthetic femoral fractures around an unstable cemented femoral stem traditionally requires removal of existing cement. We propose a new technique whereby a well-fixed cement mantle can be retained in cases with simple fractures that can be reduced anatomically when a cemented revision is planned. This technique is well established in femoral stem revision, but not in association with a fracture.Patients and methods We treated 23 Vancouver type B periprosthetic femoral fractures by reducing the fracture and cementing a revision stem into the pre-existing cement mantle, with or without supplementary fixation.Results 3 patients died in the first 6 months for reasons unrelated to surgery. In addition, 1 was too frail to attend follow-up and was therefore excluded from the study, and 1 patient underwent revision surgery for a nonunion. The remaining 18 cases all healed with radiographic union after an average time of 4.4 (2–11) months. There was no sign of loosening or subsidence of the revision stems within the old cement mantle in any of these cases at the most recent follow-up after an average of 3 (0.3–9) years.Interpretation Our results support the use of the cement-in-cement revision in anatomically reducible periprosthetic fractures with a well-preserved pre-existing cement mantle. This technique is particularly useful for the elderly patient and for those who are not fit for prolonged surgical procedures.