Abstract
We developed an endoscopically controlled device for cement removal out of the femoral canal. This system (Swiss OrthoClast) uses simple ballistic principles to effect mechanical fracturing of the bone cement. A special extraction set facilitates removal of the distal cement layer and of the intramedullary plug. The cement removal procedure, even in the depth of the femur, is controlled with an endoscopical system via monitor. Handling of this device will be demonstrated. We report our clinical results of 45 procedures with this device.
Material and methods: 45 patients (14 male ,31 female, average age at revision 72.9 years) were revised after an average follow-up period of 91.2 months (range 0-252 months) after primary THR due to mechanical loosening (n=38) or infection (n=7). All procedures were analysed and evaluated with a standardized documentation.
Results: 90% of the revisions showed type 1 bone defects according to Paprosky’s classification. In all but three cases cement removal with this method was complete. We saw one case of femoral fissuration in a patient with osteoporosis and one cortical perforation while drilling in the K-wire of the extraction tool. The time for cement removal varied between 5 and 75 minutes with an average of 27.1 minutes in the aseptical and 36.9 minutes in the septical group. Only in the very first cases we had problems with the endoscopic view.
Conclusion: Swiss OrthoClast facilitate cement removal out of the femur and avoids cortical fenestration. The optical system is effective and helpful, even for extraction of the distal cement layer and the medullary plug. This mechanical system has no side effects like development of heat, dust or toxic products during cement removal. Disadvantages might be the learning curve for the surgeon and its costs.
The abstracts were prepared by Nico Verdonschot. Correspondence should be addressed to him at Orthopaedic Research Laboratory, University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
