[Attachment tube for soft tissue reconstruction after implantation of a mega-endoprosthesis]. / Der Anbindungsschlauch zur Weichteilrekonstruktion nach Megaprothesenimplantation.

ABSTRACT

OBJECTIVE: To restore function and an active range of motion, and stabilize the joint after joint resection. INDICATIONS Restoration of a joint capsule following reconstruction of a defect using a proximal humerus and femur prosthesis. Reattachment of tendons and muscles. CONTRAINDICATIONS Acute or chronic infection. Status after cured infection. SURGICAL TECHNIQUE The attachment tube (Implantcast, Buxtehude, Germany) is attached to the joint capsule (proximal humerus and femur replacement) or directly to the prosthesis (for proximal tibial replacements) using nonresorbable Ethibond® sutures (Johnson & Johnson Medical, Norderstedt, Germany). Bone anchors are used, if the joint capsule has been completely resected. The body of the prosthesis, which has previously been attached to the shaft, is then pulled distally through the tube, and a (bipolar) head or humerus cap is placed on top of it. In the proximal humerus and femur replacement, proximal slitting of the tube may be helpful to reposition the prosthesis under vision. Following repositioning, fixation of the tube is completed ventrally and the slits previously made in the tube are sutured. Fixation of the tube to the prosthesis is carried out either with Ethibond® sutures placed around the tube, or--for a proximal humerus and tibia replacement--it is possible to attach suture material to the prosthesis through eyelets. POSTOPERATIVE MANAGEMENT Further treatment basically depends on the location of the mega-endoprosthesis used. RESULTS: Macroscopically and microscopically, fibroblasts migrate into the tube's mesh, so that attachment of the soft tissue takes place. As of yet, no cases of luxation have occurred when the tube is used in combination with a bipolar head, and with fixed-implant cups the risk of luxation can be reduced using tripolar cup systems. In patients with a proximal tibial replacement, active straightening of the knee joint can be restored in most cases, although some limitation on active extension is still possible depending on the extent of the tumor resection.