TRAUMA SURGERY Is augmentation a possible salvage procedure after lateral migration of the proximal femur nail antirotation? S. Erhart • C. Kammerlander • R. El-Attal • W. Schmoelz Received: 2 February 2012 / Published online: 3 July 2012 Ó Springer-Verlag 2012 Abstract Introduction Failed fracture fixation of proximal femur fractures in the elderly usually results in prosthetic replacement. In case of the proximal femur nail antirotation (PFNA), during lateral blade migration or periimplant fracture at the femoral shaft, the femoral head remains intact and therefore a joint preserving procedure might be performed. However, implant anchorage in the femoral head after the second blade implantation generally results in reduced anchorage in the remaining cancellous bone. Therefore, we hypothesize that in the above mentioned cases augmentation of the PFNA blade could be a treat- ment option before prosthetic surgery has to be performed. Materials Biomechanical investigations were performed in eight fresh frozen femoral heads. Implant anchorage in case of blade extraction and reinsertion was investigated by rotation and pull out of a PFNA blade with a servohy- draulic testing machine. After reinsertion of the blade and augmentation with bone-cement, the anchorage of the blade was investigated again to observe changes in torque and pull-out force. Results Rotational stability of the implant significantly increased after augmentation of the prior extracted PFNA blade. Pull-out strength was higher in the revised case than in the initial tests but without statistical significance. After augmentation, correlation between bone mineral density and pull-out strength which was found during initial pull- out disappeared. Discussion Augmentation of simulated blade exchange after lateral blade migration demonstrated a good anchorage. There was superior rotational stability in the revised case and no inferiority during pull out for the investigated specimens. Furthermore, augmentation could compensate for destroyed trabeculae and poor bone stock. It could furthermore be an option when a failed implant has to be replaced by a long PFNA in case of shaft fracture at the tip of the implant to increase anchorage in the femoral head. From a biomechanical point of view, reosteosynthesis and augmentation in selected cases of PFNA revision could be an alternative to initial prosthetic replacement. In the case of cut-out or medial implant protrusion, the suggested salvage tech- nique is not feasible. Keywords Proximal femur fracture Á Complications Á Cement augmentation Á Osteoporosis Introduction New implant designs for proximal femur fractures could significantly reduce complications like cut-out or cut- through in the last years [1, 2]. However, inadequate fracture reduction and suboptimal implant position still remain treatment-specific risk factors for the mentioned complications [3, 4]. Especially eccentric implant position increases stress on the implant and therefore might cause catastrophic failure [5]. These failures are mainly seen in severely osteoporotic patients with a considerably reduced bone stock [6]. After the mentioned complications, the treatment of choice would be implant removal and pros- thetic replacement of the proximal femur [7]. This, how- ever, poses a higher intra and postoperative risk to the patient [8] and furthermore a considerable financial burden to the health system. S. Erhart Á C. Kammerlander Á R. El-Attal Á W. Schmoelz (&) Department for Trauma Surgery, Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria e-mail: werner.schmoelz@uki.at 123 Arch Orthop Trauma Surg (2012) 132:1577–1581 DOI 10.1007/s00402-012-1579-3