No abstract

In a survey of 1500 coronal sinonasal CT scans, 46 patients were found to have paranasal sinus osteomas. The overall incidence was 3%, with a predilection for decades 5 and 6 and a male-to-female ratio of 1.3:1. The frontal sinus was most commonly involved, and of these lesions 37% were in the immediate vicinity of the nasofrontal duct and 21% above and lateral to the ostium. Tumour size varied from a mean diameter of 1.5 mm to 30 mm; however, 17 lesions were 5 mm in size or less. Five matrix patterns were observed. Only two patients were symptomatic and only three osteomas excised. Isotope bone scanning may be a useful screening test with specific follow-up utilising computed tomography.

Prior studies have suggested that biomodels enhance patient education, preoperative planning and intra-operative stereotaxy; however, the usefulness of biomodels compared to regular imaging modalities such as X-ray, CT and MR has not been quantified. Our objective was to quantify the surgeon's perceptions on the usefulness of biomodels compared to standard visualisation modalities for preoperative planning and intra-operative anatomical reference. Physical biomodels were manufactured for a series of 26 consecutive patients with complex spinal pathologies using a stereolithographic technique based on CT data. The biomodels were used preoperatively for surgical planning and customising implants, and intraoperatively for anatomical reference. Following surgery, a detailed biomodel utility survey was completed by the surgeons, and informal telephone interviews were conducted with patients. Using biomodels, 21 deformity and 5 tumour cases were performed. Surgeons stated that the anatomical details were better visible on the biomodel than on other imaging modalities in 65% of cases, and exclusively visible on the biomodel in 11% of cases. Preoperative use of the biomodel led to a different decision regarding the choice of osteosynthetic materials used in 52% of cases, and the implantation site of osteosynthetic material in 74% of cases. Surgeons reported that the use of biomodels reduced operating time by a mean of 8% in tumour patients and 22% in deformity procedures. This study supports biomodelling as a useful, and sometimes essential tool in the armamentarium of imaging techniques used for complex spinal surgery.