[The challenge of revising a well-fixed curved calcar-guided short stem in total hip arthroplasty: Introduction of a new curved extraction chisel system]. / Herausforderung: Revision eines fest eingewachsenen kurvierten Kurzschaftes in der Hüftendoprothetik : Vorstellung eines neuen, kurvierten Extraktions-Meißel-Systems.

OBJECTIVE: Safe and bone-conserving extraction of a well-fixed curved short stem without the necessity of a transfemoral approach. INDICATIONS: The revision of a well-fixed curved short stem, for example, due to periprosthetic infection or malposition. Meticulous preparation of the cone and the lateral shoulder of the stem. CONTRAINDICATIONS: Correct placement of the chuck not possible. SURGICAL TECHNIQUE: Choice of a standard approach to the hip joint. Luxation. Removal of the implanted head. Preparation of the proximal femur and removal of bone at the stem shoulder. Attachment of the chuck to the cone. Insertion of the "prestarter" chisels through the guided slots of the chuck, starting with the lateral chisel, followed by the ventral and dorsal chisel. The cut must point outwards away from the implant. Repetition of this procedure using the "starter" chisels in the same order. Removal of the chuck. Careful insertion of the "final" chisels in the same order. Trial of a stem extraction using an extraction tool. Optional repetition of the whole procedure. In order to avoid fractures, opening of the medial interface only after preparation laterally, ventrally and dorsally, by careful insertion of the medial chisels in the respective order alongside the calcar. Finally, extraction of the stem. POSTOPERATIVE MANAGEMENT: Postoperative protocol according to the respective revision implants and fixation technique used. RESULTS: The described procedure has proven successful in clinical practice in the three author affiliations in a total of 14 cases. In 3 (21.4%) cases, despite the use of the extraction chisel system, an additional transfemoral approach or fenestration had to be performed to remove the short stem. Primary straight stems were used in over half of the cases (57.8%) as revision implants, whereas in 4 cases (36.4%) a cementless short stem could again be used.