INTRODUCTION.
Resecting bone tumours within the pelvis is highly challenging and requires good cutting accuracy to achieve sufficient margins. Computer-assisted technologies such as intraoperative navigation have been developed for pelvic bone tumour resection. Patient-specific instruments have been transposed to tumour surgery. The present study reports a series of 11 clinical cases of PSI-assisted bone tumour surgery within the pelvis, and assesses how accurately a preoperative resection strategy can be replicated intraoperatively with the PSI. The patient series consisted in 11 patients eligible for curative surgical resection of primary bone tumor of the pelvis. Eight patients had a bone sarcoma of iliac bone involving the acetabulum, two patients had a sacral tumor, and one patient had a chondrosarcoma of proximal femur with intra-articular hip extension. Resection planning was preoperatively defined including a safe margin defined by the surgeon from 3 up to 15 mm. PSI were designed using a computer-aided design software according to the desired resection strategy and produced by additive manufacturing technology. Intraoperatively, PSI were positioned freehand by the surgeon and fixed on the bone surface using K-wires. The standard surgical approach has been used for each patient. Dissection was in accordance with the routine technique. There was no additional bone exposure to position the PSI. Histopathological analysis of the resected tumor specimens was performed to evaluate the achieved resection margins. Postoperative CT were acquired and matched to the preoperative CT to assess the local control of the tumor. Two parameters were measured: achieved resection margin (minimum distance to the tumor) and location accuracy (maximum distance between achieved and planned cuttings; ISO1101 standard). PSI were quick and easy to use with a positioning onto the bone surface in less than 5 minutes for all cases. The positioning of the PSI was considered unambiguous for all patients. Histopathological analysis classified all achieved resection margins as R0 (tumor-free), except for two patients : R2 because of a morcelised tumour and R1 in soft tissues. The errors in safe margin averaged −0.8 mm (95% CI: −1.8 mm to 0.1 mm). The location accuracy of the achieved cut planes with respect to the desired cut planes averaged 2.5 mm (95% CI: 1.8 to 3.2 mm). Results in terms of safe margin or the location accuracy demonstrated how PSI enabled the surgeon to intraoperatively replicate the resection strategies with a very good cutting accuracy. These findings are consistent with the levels of bone-cutting accuracy published in the literature. PSI technology described in this study achieved clear bone margins for all patients. Longer follow-up period is required but it appears that PSI has the potential to provide clinically acceptable margins.
Introduction. Clear operative oncological margins are the main target in malignant
Aims and methods. We present a review of our use of the Ilizarov apparatus in a non-acute NGO hospital in Cambodia specialising in limb reconstruction. Frames are applied without on table image intensification. A retrospective case-note analysis of Ilizarov apparatus use for all indications was conducted. 53 frames were applied between November 2005 and October 2011. Indications for application were chronic open fracture, osteomyelitis, fracture malunion, infective and non-infective non-union, bone lengthening, primary
Introduction. Three-dimensional preoperative planning and
Minimally invasive placement of iliosacral screws (SI-screw) is becoming the standard surgical procedure for sacrum fractures. Computer navigation seems to increase screw accuracy and reduce intraoperative radiation compared to conventional radiographic placement. In 2012 an interdisciplinary hybrid operating theatre was installed at the University of Ulm. A floor-based robotic flat panel 3D c-arm (Artis zeego, Siemens, Germany) is linked to a navigation system (BrainLab Curve, BrainLab, Germany). With a single intraoperative 3D scan the whole pelvis can be visualised in CT-like quality. The aim of this study was to analyse the accuracy of SI-screws using this hybrid operating theater. 32 SI-screws (30 patients) were included in this study. Indications ranged from
CT and MRI scans are complementary preoperative imaging investigations for planning complex musculoskeletal