Der proximale und komplette Femurersatz

Abstract

A total of 20 patients with proximal femur replacement and 2 patients with total femur replacement implanted between June 2007 and December 2011 were retrospectively reviewed. Three patients had primary malignant bone tumors, while 19 patients underwent resection for metastatic disease. The mean age at surgery was 62.0 ± 18.1 years (18-82 years). Fifteen patients with a mean follow-up of 20.3 ± 17.2 months (4-51 months) were studied. Among the 22 cases, periprosthetic infection occurred in 3 patients (13.6%), dislocation in 2 patients (9.1%). Evaluation of the functional outcome in 15 patients using the MSTS score by Enneking revealed 3 very good (20%), 4 good (26.7%), 6 fair (40%), and 2 poor (13.3%) results.

Influence of cerclages on primary stability of tumor megaprostheses subjected to distal femur defects

“…The stem was implanted using the universal material testing machine (Inspekt table blue 20, Hegewald & Peschke, Nossen, Germany) according to a standardized protocol (25 axial loading cycles of 2 kN and 25 axial loading cycles of 4 kN) [13][14][15]. Due to the press-fit situation during the implantation, most femora models showed a provoked crack formation when the implant was set, which confirmed literature results, that fractures may occur during or after implantation when using this prosthesis [5]. If a crack formation was initiated during implantation, the implant was removed immediately and the originated bone defect was fixed by means of CoCrNi-alloy multifilament cerclages (Dall Miles Cable System, Stryker, Duisburg, Germany) with a diameter of 1.6 mm at 20.5 cm and 14.0 cm distal to lesser trochanter (Fig.…”

“…Complications such as periprosthetic fractures during implantation [5,10] or high postoperative stresses [6] result in the need of reconstruction of the fractured bones by means of allografts and/or osteosynthetic devices like -in this case -cerclages [5,12,13]. Therefore, we examined the influence of cerclages of fractured synthetic femora by means of primary stability measurements of the MUTARS 1 system.…”

“…The majority of structural failures are established as fractures and may go unnoticed intraoperatively and often occur at the distal third of the femur [11]. In case of periprosthetic fractures either during implantation [5,10] or high postoperatively stresses during knee flexion due to high lever arms of the megaprosthesis [12], the fractured bone requires reconstruction with allografts or cerclages [5,13,14]. Thus, the purpose of this experimental study was to investigate the influence of cerclages on the reconstructed bones by means of primary stability measurements of the MUTARS 1 system, using distally fractured synthetic femora.…”

“…In the past, standard treatment of these tumors consisted in transfemoral amputation or rotationplasty. Due to early diagnosis, neoadjuvant chemotherapy and the development and acceptance of modular megaprostheses around 95% of today's patients can be treated with limb salvage surgery [1][2][3][4][5][6][7] which is commonly used as conventional and satisfying therapy [1,5]. After surgery, femur reconstruction is primarily realized with megaprostheses to gain stable function and facilitate returning to social life [8].…”

Short-stem reconstruction for megaendoprostheses in case of an ultrashort proximal femur

“…This leads to disruption of all the muscles in the proximal femur and leads to a poorer functional outcome, including Trendelenburg limp, in comparison with distal femur replacement [1,7,8]. In addition to the problems resulting from distal femur resection, a risk of luxation of the hip is also present [4,8]. To delay or avoid resection of the hip joint in patients with an ultrashort proximal femur shaft, we use a short stem called the “Buxtehude stem” (Implantcast Ltd., Buxtehude, Germany).…”