Mechanical complications were the most common cause of implant failure. Infection was the leading cause of both complication and amputation; risk of infection increased substantially with revision surgery. Modular implants had fewer mechanical complications, thus leading to fewer revisions and subsequent infections.

Background Long-term survival of distal femoral endoprosthetic replacements is largely affected by aseptic loosening. It is unclear whether and to what degree surgical technique and component selection influence the risk of loosening. Questions/purposes We (1) established the overall failure and aseptic loosening rates in a tumor population and asked (2) whether stem diameter and specifically the diaphysisto-stem ratio predicts loosening, and (3) whether resection percentage correlates with failure. Methods We retrospectively reviewed the charts of all 93 patients in whom 104 distal femoral replacements had been performed from 1985 to 2008. We extracted the following data: age, need for revision surgeries, tumor diagnosis, adjunct treatment, and implant characteristics. We reviewed radiographs and determined stem size, bone diaphyseal width, and resection percentage of the femur. Kaplan-Meier survivorship was calculated for all implant failures and failures resulting from aseptic loosening. We evaluated radiolucent lines in patients with radiographic followup over 5 years. We identified independent risk factors for loosening. The minimum followup for radiographic evaluation was 5 years (mean, 12.7 years; range, 5.4-23.5 years).

Background Postoperative spine infections cause considerable morbidity. Patients are subjected to long-term antibiotic regimens and may require further surgery. Delivery of electric current through instrumentation can detach biofilm, allowing better antibiotic penetration and assisting in eradicating infection. Question/purposes We asked (1) whether capacitive coupling treatment in combination with a single dose of antibiotics would reduce infection rates when compared with antibiotics alone in a rabbit spine infection model, (2) whether it would decrease the overall bacterial burden, and (3) whether there was a time-dependent response based on days treated with capacitive coupling. Methods Thirty rabbits were subjected to a well-established spine infection model with a single dose of intravenously administered systemic ceftriaxone (20 mg/kg of body weight) prophylaxis. Two noncontiguous rods were implanted inside dead space defects at L3 and L6 challenged with 10 6

Although a long-stemmed cemented hemiarthroplasty is frequently recommended for oncologic lesions of proximal femur, we have observed an alarming number of spontaneous stem fractures. The purpose of this retrospective study was to identify the associated risk factors for stem fractures in a study cohort of 60 (61 prostheses) during 1983-2007. At a mean follow-up of 41 months, 4/61 (6.6%) stems had fractured after a mean of 36 (12-92) months after surgery. All failed implants were Osteonics Omnifit (4/27; 14.8%) and multivariate analysis did not show any correlation with other studied variables. While the failures were successfully salvaged by conversion to a modular proximal femoral replacement, any implant failure in this population is devastating. Spontaneous onset of thigh pain in patients with long stems, particularly if associated with other risk factors, should raise suspicion of a fatigue fracture of the stem.