Surgeon's and patient's radiation exposure during percutaneous thoraco-lumbar pedicle screw fixation: A prospective multicenter study of 100 cases.

HYPOTHESIS: Percutaneous pedicle screw fixations (PPSF) are increasingly used in spine surgery, minimizing morbidity through less muscle breakdown but at the cost of intraoperative fluoroscopic guidance that generates high radiation exposure. Few studies have been conducted to measure them accurately. MATERIAL AND METHODS: The objective of our study is to quantify, during a PPSF carried out in different experimented centers respecting current radiation protection recommendations, this irradiation at the level of the surgeon and the patient. We have prospectively included 100 FPVP procedures for which we have collected radiation doses from the main operator. For each procedure, the doses of whole-body radiation, lens and extremities were measured. RESULTS: Our results show a mean whole body, extremity and lens exposure dose per procedure reaching 1.7±2.8µSv, 204.7±260.9µSv and 30.5±25.9µSv, respectively. According to these values, the exposure of the surgeon's extremities and lens will exceed the annual limit allowed by the International Commission on Radiological Protection (ICRP) after 2440 and 4840 procedures respectively. CONCLUSION: Recent European guidelines will reduce the maximum annual exposure dose from 150 to 20mSv. The number of surgical procedures to not reach the eye threshold, according to our results, should not exceed 645 procedures per year. Pending the democratization of neuronavigation systems, the use of conventional fluoroscopy exposes the eyes in the first place. Therefore they must be protected by leaded glasses. LEVEL OF PROOF: IV, case series.

Surgical-site infection in spinal injury: incidence and risk factors in a prospective cohort of 518 patients.

PURPOSE: To investigate the incidence of surgical-site infection (SSI) and determinate the risk factors of SSI in the context of spinal injury. METHODS: From February 1, 2011 to July 31, 2011, for a multicentre cohort of patients with acute spinal injury, we prospectively censored those with SSI for at least 12 months. We recorded epidemiologic characteristics and details of surgical procedure and postoperative care for each patient. We calculated the incidence of SSI at 1, 3 and 12 months after surgery. Univariate and multivariate analysis were used to establish the association of risk factors and SSI. We studied clinical outcomes by a visual analog scale for pain and physical and mental component summaries (PCS and MCS) of the Medical Outcomes Survey 36-Item Short Form (SF-36). RESULTS: At 1 year, among 518 patients, we recorded 25 SSI events, with median occurrence at 16 days (25-75 % quartile: 13-44 days). Incidence of SSI was 3.2 % (95 % confidence interval [1.9-5.3 %]) at 1 month, 3.7 % (95 % [2.2-5.8 %]) at 3 months and 4.6 % (95 % CI [3-6.9 %]) at 12 months. On multivariate analysis, age, presence of diabetes and surgical duration were predictors of SSI (p = 0.009, p = 0.047, and p = 0.015 respectively). At 12 months, infected and non-infected patients did not differ in pain (p = 0.58) or SF-36 PCS (p = 0.8) or MCS (p = 0.68). CONCLUSIONS: In this large prospective multicentre study in the context of spinal injury, we obtained an equivalent incidence rate and risk factors of SSI as found in the literature for elective spinal surgery.