A long nail is often recommended for treatment of complex trochanteric fractures but requires longer surgical and fluoroscopy times. A possible solution could be a nail with an appropriate length which can be locked in a minimally invasive manner by the main aiming device. We aimed to determine if such a nail model* offers similar structural stability on biomechanical testing on artificial bone as a standard long nail when used to treat complex trochanteric fractures. An artificial osteoporotic bone model was chosen. As osteosynthesis material two cephalomedullary nails (CMN) were chosen: a superior locking nail (SL-Nail) which can be implanted with a singular targeting device, and a long nail (long-nail) with distal locking using free-hand technique. AO31-A2.2 fractures were simulated in a standardized manner. The insertion of the nail was strictly in accordance with the IFU and surgical manual of the manufacturer. The nail was locked dynamically proximally and statically distally. Axial height of the construct, varus collapse, and rotational deformity directly after nail insertion were simulated. A Universal Testing Machine was used. Measurements were made with a stereo-optic tracking system. Reactive movements were recorded and evaluated in all six degrees of freedom. A comparative analysis provided information about the stability and deformation of the assemblies to be compared.Introduction
Method
We report on a patient with an unusual pulmonary infection after resection of a high-grade osteosarcoma. In March 2007 a 30-year old female with pain and swelling of the left proximal humerus was submitted to the orthopaedic department. Rx and CT revealed a tumour with destruction and invasion of the surrounding soft tissue. Incision biopsy led to the diagnosis of osteoblastic osteosarcoma. She was enrolled into the EURAMOS protocol and received neoadjuvant chemotherapy. In July 2007 an extra-articular resection of the proximal humerus with modular endoprosthetic replacement was performed. The sarcoma had responded well to chemotherapy (regression grade 3 according to Salzer-Kunts-chik). Surprisingly, the resection specimen demonstrated a “skip lesion” of vital sarcoma in the resection line not been detected by preoperative PET or MRT. After consultation of the German study group she was stratified into the standard risk group. 12 months later a control CT revealed multiple foci in both lungs, which were highly suspicious for pulmonary metastases. All clinical parameters were normal. A lung biopsy was performed by thoracotomy and a granulomatous infection was diagnosed, which was suspicious for tuberculosis. Extended microbiological investigations by culture and PCR analysis revealed an infection by Myco-bacterium Xenopi, which is a rare form of an atypical mycobacteriosis. Since then she is treated accordingly, however the infection has progressed and involvement of the liver has been diagnosed by cutting needle biopsy.
In our outpatient clinic we have assessed the clinical follow-up as clinical examination (Enneking-score) and standardized radiological follow-up for 5 years, then once per year. In the focus of interest were aseptic loosening of the stems, wear of polyethylene, and mechanical problems as implant failure
We conclude that in tumour patients with major osseous reconstruction after wide resection a certain loss ob function cannot be avoided, but the rate of complications in the long-term-follow-up after implantation of modular tumour prosthesis is acceptable.
