Cement removal with an endoscopically controlled ballistically driven chiselling system

In this paper, we introduce a newly developed miniaturised chiselling system (Swiss OrthoClast) which allows endoscopically controlled cement removal even from deep within the femur in hip revision arthroplasty. The intraoperative handling is demonstrated and illustrated. The device consists of a control unit, a handpiece, a set of chisels of different lengths, shape, and tip geometry, a set of plug extraction tools, and a special intrafemoral endoscope. It uses simple ballistic principles to effect fracturing of the bone cement. Inside the handpiece the projectile is accelerated and strikes the chisel head. The tip moves at high speed and with a small excursion towards the cement, which is fragmented mechanically by the movement of the chisel tip without generating heat. The device is being validated in a prospective, international, multicenter study, and we include here the results of the first 28 clinical procedures of cement removal. The duration of the procedure varied from 13 to 75 min, with an average of 32 min. In all but one case, the cement was completely removed. We noted one case of cortical fissuring.