Clinical validation of the accuracy of an intra-operative assessment tool using 3D ultrasound compared to histopathology in patients with squamous cell carcinoma of the tongue.

BACKGROUND: Histopathological analysis often shows close resection margins after surgical removal of tongue squamous cell carcinoma (TSCC). This study aimed to investigate the agreement between intraoperative 3D ultrasound (US) margin assessment and postoperative histopathology of resected TSCC. METHODS: In this study, ten patients were prospectively included. Three fiducial cannulas were inserted into the specimen. To acquire a motorized 3D US volume, the resected specimen was submerged in saline, after which images were acquired while the probe moved over the specimen. The US volumes were annotated twice: (1) automatically and (2) manually, with the automatic segmentation as initialization. After standardized histopathological processing, all hematoxylin-eosin whole slide images (WSI) were included for analysis. Corresponding US images were found based on the known WSI spacing and fiducials. Blinded observers measured the tumor thickness and the margin in the caudal, deep, and cranial directions on every slide. The anterior and posterior margin was measured per specimen. RESULTS: The mean difference in all measurements between manually segmented US and histopathology was 2.34 (SD: ±3.34) mm, and Spearman's rank correlation coefficient was 0.733 (p < 0.001). The smallest mean difference was in the tumor thickness with 0.80 (SD: ±2.44) mm and a correlation of 0.836 (p < 0.001). Limitations were observed in the caudal region, where no correlation was found. CONCLUSION: This study shows that 3D US and histopathology have a moderate to strong statistically significant correlation (r = 0.733; p < 0.001) and a mean difference between the modalities of 2.3 mm (95%CI: -4.2; 8.9). Future research should focus on patient outcomes regarding resection margins.

The effect of tremor on disability assessment in chronic inflammatory demyelinating polyradiculoneuropathy.

Tremor in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is common, often unresponsive to treatment, and may contribute to disability. We aim to investigate whether tremor is associated with disability as measured in daily practice and clinical trials, independent of other impairments. We included 76 CIDP patients in this cross-sectional study. We assessed tremor with the Tremor Research Group essential tremor rating assessment scale (TETRAS) and the Fahn-Tolosa-Marin clinical rating scale (FTM). Disability was measured with the inflammatory Rasch-built overall disability scale (I-RODS) and the adjusted Inflammatory Neuropathy Cause and Treatment disability scale (INCAT-DS, categorized separately in arm score, or total score). Impairments including strength, sensory impairment, and fatigue were measured using specific impairment scales. We tested whether "the presence of a clinically relevant tremor" (based on TETRAS and FTM) or "tremor severity" (FTM part B sum score) was associated with disability scores (I-RODS, INCAT-DS total score, and INCAT-DS arm score), independent of the impairment scores, using multivariate regression. Both "the presence of a clinically relevant tremor" and "tremor severity" were significantly associated with disability measured by the INCAT-DS (arm score and total score), but not the I-RODS, independent of strength, sensory impairment, and fatigue. The explained variances were low. Clinically relevant tremor can (partly) explain disability in CIDP, as measured with the INCAT-DS, independent of muscle strength, sensory deficits, and fatigue. To assess disease activity in CIDP patients with tremor, both impairment and disability outcomes should be assessed, as disability is caused partly by tremor while the effect of immunotherapy on tremor seems limited.

Evaluation of CPAP adherence in bariatric patients diagnosed with obstructive sleep apnea: outcomes of a multicenter cohort study.

PURPOSE: Obstructive sleep apnea (OSA) is highly prevalent but mostly undiagnosed in obese patients scheduled for bariatric surgery. To prevent cardiopulmonary complications, many clinics perform preoperative OSA screening. Consequently, adequate adherence to continuous positive airway pressure (CPAP) therapy is essential but challenging. We aimed to evaluate CPAP adherence and its influence on postoperative outcomes. METHODS: In a prospective multicenter cohort study, we compared different perioperative strategies for handling undiagnosed OSA in bariatric patients. In this subgroup analysis, patients newly diagnosed with OSA were compared to those with pre-existing OSA. We assessed inadequate CPAP adherence, defined as < 4 h/night, between the preoperative period and 6 months postoperative. Cardiopulmonary complications and (un)scheduled ICU admissions were also evaluated. RESULTS: In total, 272 patients with newly diagnosed OSA (67.4%) and 132 patients with pre-existing OSA (32.6%) were included. Before surgery, 41 newly diagnosed patients used CPAP inadequately, compared to 5 patients with pre-existing OSA (15% vs. 4%, p = 0.049). Six months after surgery, inadequate CPAP use increased to 73% for newly diagnosed patients and 39% for patients with pre-existing OSA, respectively (p < 0.001). Incidences of cardiopulmonary complications, scheduled, and unscheduled ICU admissions were similar in the two study groups (p = 0.600, p = 0.972, and p = 0.980, respectively). CONCLUSION: Inadequate CPAP adherence is higher in bariatric patients newly diagnosed with OSA when compared to patients with pre-existing OSA. Strategies to increase CPAP adherence may be valuable when considering routine OSA screening and CPAP therapy in patients undergoing bariatric surgery. Further studies are needed to improve current guidelines on perioperative OSA management of obese patients. TRIAL REGISTRATION: POPCORN study, registered at Netherlands Trial Register, https://www.trialregister.nl/trial/6805 . ID no: 6805.

Complications and predictors associated with moderate to severe obstructive sleep apnoea in bariatric surgery: Evaluation of routine obstructive sleep apnoea screening.

PURPOSE: Obstructive sleep apnoea (OSA) is a breathing disorder resulting in blockage of airflow and hypo-oxygenation. The incidence of OSA in patients with class 2 or 3 obesity (Body Mass index, BMI >35) is 60-70%. Unfortunately, most bariatric patients are unaware they suffer from OSA. Untreated OSA can lead to perioperative cardiopulmonary complications. The aim of this study was to identify predictors associated with moderate to severe OSA and asses the incidence of OSA-related complications in a large cohort of patients who underwent OSA-screening and treatment if indicated before bariatric surgery. METHODS: All consecutive patients who underwent primary bariatric surgery between September 2013 and September 2019 were included. Univariable and multivariable logistic regression analysis was performed to identify potential predictors for moderate to severe OSA using sleep studies. RESULTS: A total of 2872 patients who underwent bariatric surgery were included for analysis. Overall, OSA was identified in 62.5% of all patients and moderate to severe OSA (AHI ≥15) in 28.6%. Independent predictors for moderate to severe OSA were male gender (p < 0.001), age (p < 0.001), preoperative BMI (p < 0.001), preoperative waist circumference (p < 0.001), hypertension (p < 0.001), and dyslipidaemia (p = 0.046). The incidence of OSA-related complications was low (0.8%) and not significantly different among the different OSA severity classes. CONCLUSION: This is the largest study to assess OSA presence and OSA-related complications in patients undergoing bariatric surgery. The incidence of potential OSA-related complications was low (0.8%). We believe focus could be shifted towards more cost-efficient strategies where OSA screening is omitted such as perioperative continuous monitoring.

Correction to: Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial).

An amendment to this paper has been published and can be accessed via the original article.

Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial).

BACKGROUND: Syndesmotic injuries are common and their incidence is rising. In case of surgical fixation of the syndesmosis a metal syndesmotic screw is used most often. It is however unclear whether this screw needs to be removed routinely after the syndesmosis has healed. Traditionally the screw is removed after six to 12 weeks as it is thought to hamper ankle functional and to be a source of pain. Some studies however suggest this is only the case in a minority of patients. We therefore aim to investigate the effect of retaining the syndesmotic screw on functional outcome. DESIGN: This is a pragmatic international multicentre randomised controlled trial in patients with an acute syndesmotic injury for which a metallic syndesmotic screw was placed. Patients will be randomised to either routine removal of the syndesmotic screw or removal on demand. Primary outcome is functional recovery at 12 months measured with the Olerud-Molander Score. Secondary outcomes are quality of life, pain and costs. In total 194 patients will be needed to demonstrate non-inferiority between the two interventions at 80% power and a significance level of 0.025 including 15% loss to follow-up. DISCUSSION: If removal on demand of the syndesmotic screw is non-inferior to routine removal in terms of functional outcome, this will offer a strong argument to adopt this as standard practice of care. This means that patients will not have to undergo a secondary procedure, leading to less complications and subsequent lower costs. TRIAL REGISTRATION: This study was registered at the Netherlands Trial Register (NTR5965), Clinicaltrials.gov ( NCT02896998 ) on July 15th 2016.

Less negative appendectomies due to imaging in patients with suspected appendicitis.

BACKGROUND: The optimal diagnostics and treatment of acute appendicitis continues to be a challenge. We evaluated the implementation of the guideline "diagnostics and treatment in acute appendicitis" in 2010. This guideline states that, in every patient with clinically suspected acute appendicitis, an ultrasonography or CT scan is advised to confirm the diagnosis before surgery. PATIENTS AND METHODS: We selected all consecutive patients with acute appendicitis in our hospital in the years 2008 and 2011. We compared the use of imaging and the operation results in both years. RESULTS: In 2008, 228 patients were treated for acute appendicitis. In 43 %, imaging was performed. In 2011, 238 patients were treated; in 99 % of the cases, imaging was performed. A decrease in patients with negative appendectomy was seen from 19 % in 2008 to 5 % in 2011. Financial analysis showed a reduction in costs favoring 2011. CONCLUSIONS: The increased use of pre-operative imaging in patients with suspected acute appendicitis resulted in a cost-effective way to decrease the number of patients with negative appendectomies.

The effects of a Virtual Fracture Care review protocol on secondary healthcare utilization in trauma patients requiring semi-acute surgery: a retrospective cohort study.

Purpose: The demand for trauma care in the Netherlands is increasing due to a rising incidence of injuries. To provide adequate trauma care amidst this increasing pressure, a Virtual Fracture Care (VFC) review protocol was introduced for treatment of musculoskeletal injuries to the extremities (MIE). This study aimed to assess the influence of the Dutch VFC review protocol on secondary healthcare utilization (i.e., follow-up appointments and imaging) in adult trauma patients (aged ≥18 years) who underwent semi-acute surgery (2-14 days after initial presentation) for MIE, compared to traditional workflows. We hypothesized utilization of VFC review would lead to reduced secondary healthcare utilization. Methods: This retrospective cohort study assessed the influence of VFC review on secondary healthcare utilization in adult trauma patients (aged ≥18 years) who underwent semi-acute surgery for a MIE. Patients treated before VFC review and the COVID-19 pandemic, from 1st of July 2018 to 31st of December 2019, formed a pre-VFC group. Patients treated after VFC review implementation from January 1st 2021 to June 30th 2022, partially during and after the COVID-19 pandemic (including distancing measures), formed a VFC group. Outcomes were follow-up appointments, radiographic imaging, time to surgery, emergency department reattendances, and complications. The study was approved by the local ethical research committee approved this study (WO 23.073). Results: In total, 2,682 patients were included, consisting of 1,277 pre-VFC patients, and 1,405 VFC patients. Following VFC review, the total number of follow-up appointments reduced by 21% and a shift from face-to-face towards telephone consultations occurred with 19% of follow-up appointments performed by telephone in the VFC group vs. 4% in the pre-VFC group. Additionally, VFC review resulted in a 7% reduction of radiographs, improved time scheduling of surgery, and a 56% reduction of emergency department reattendances. Registered complication rates remained similar. Conclusion: The utilization of VFC review for management of adult patients with a MIE requiring semi-acute surgery improves efficiency compared to traditional workflows. It results in a 21% follow-up appointment reduction, a shift from face-to-face to remote delivery of care, fewer radiographs, improved time scheduling of surgery, and reduces emergency department reattendances by 56%.

Computer-aided design and fabrication of nasal prostheses: a semi-automated algorithm using statistical shape modeling.

PURPOSE: This research aimed to develop an innovative method for designing and fabricating nasal prostheses that reduces anaplastologist expertise dependency while maintaining quality and appearance, allowing patients to regain their normal facial appearance. METHODS: The method involved statistical shape modeling using a morphable face model and 3D data acquired through optical scanning or CT. An automated design process generated patient-specific fits and appearances using regular prosthesis materials and 3D printing of molds. Manual input was required for specific case-related details. RESULTS: The developed method met all predefined requirements, replacing analog impression-making and offering compatibility with various data acquisition methods. Prostheses created through this method exhibited equivalent aesthetics to conventionally fabricated ones while reducing the skill dependency typically associated with prosthetic design and fabrication. CONCLUSIONS: This method provides a promising approach for both temporary and definitive nasal prostheses, with the potential for remote prosthesis fabrication in areas lacking anaplastology care. While new skills are required for data acquisition and algorithm control, these technologies are increasingly accessible. Further clinical studies will help validate its effectiveness, and ongoing technological advancements may lead to even more advanced and skill-independent prosthesis fabrication methods in the future.

Implementing a deep learning model for automatic tongue tumour segmentation in ex-vivo 3-dimensional ultrasound volumes.

Three-dimensional (3D) ultrasound can assess the margins of resected tongue carcinoma during surgery. Manual segmentation (MS) is time-consuming, labour-intensive, and subject to operator variability. This study aims to investigate use of a 3D deep learning model for fast intraoperative segmentation of tongue carcinoma in 3D ultrasound volumes. Additionally, it investigates the clinical effect of automatic segmentation. A 3D No New U-Net (nnUNet) was trained on 113 manually annotated ultrasound volumes of resected tongue carcinoma. The model was implemented on a mobile workstation and clinically validated on 16 prospectively included tongue carcinoma patients. Different prediction settings were investigated. Automatic segmentations with multiple islands were adjusted by selecting the best-representing island. The final margin status (FMS) based on automatic, semi-automatic, and manual segmentation was computed and compared with the histopathological margin. The standard 3D nnUNet resulted in the best-performing automatic segmentation with a mean (SD) Dice volumetric score of 0.65 (0.30), Dice surface score of 0.73 (0.26), average surface distance of 0.44 (0.61) mm, Hausdorff distance of 6.65 (8.84) mm, and prediction time of 8 seconds. FMS based on automatic segmentation had a low correlation with histopathology (r = 0.12, p = 0.67); MS resulted in a moderate but insignificant correlation with histopathology (r = 0.4, p = 0.12, n = 16). Implementing the 3D nnUNet yielded fast, automatic segmentation of tongue carcinoma in 3D ultrasound volumes. Correlation between FMS and histopathology obtained from these segmentations was lower than the moderate correlation between MS and histopathology.

Comparison of image quality of 3D ultrasound: motorized acquisition versus freehand navigated acquisition, a phantom study.

PURPOSE: Intra-operative assessment of resection margins during oncological surgery is a field that needs improvement. Ultrasound (US) shows the potential to fulfill this need, but this imaging technique is highly operator-dependent. A 3D US image of the whole specimen may remedy the operator dependence. This study aims to compare and evaluate the image quality of 3D US between freehand acquisition (FA) and motorized acquisition (MA). METHODS: Multiple 3D US volumes of a commercial phantom were acquired in motorized and freehand fashion. FA images were collected with electromagnetic navigation. An integrated algorithm reconstructed the FA images. MA images were stacked into a 3D volume. The image quality is evaluated following the metrics: contrast resolution, axial and elevation resolution, axial and elevation distance calibration, stability, inter-operator variability, and intra-operator variability. A linear mixed model determined statistical differences between FA and MA for these metrics. RESULTS: The MA results in a statistically significant lower error of axial distance calibration (p < 0.0001) and higher stability (p < 0.0001) than FA. On the other hand, the FA has a better elevation resolution (p < 0.003) than the MA. CONCLUSION: MA results in better image quality of 3D US than the FA method based on axial distance calibration, stability, and variability. This study suggests acquiring 3D US volumes for intra-operative ex vivo margin assessment in a motorized fashion.

A hybrid registration method using the mandibular bone surface for electromagnetic navigation in mandibular surgery.

PURPOSE: To utilize navigated mandibular (reconstructive) surgery, accurate registration of the preoperative CT scan with the actual patient in the operating room (OR) is required. In this phantom study, the feasibility of a noninvasive hybrid registration method is assessed. This method consists of a point registration with anatomic landmarks for initialization and a surface registration using the bare mandibular bone surface for optimization. METHODS: Three mandible phantoms with reference notches on two osteotomy planes were 3D printed. An electromagnetic tracking system in combination with 3D Slicer software was used for navigation. Different configurations, i.e., different surface point areas and number and configuration of surface points, were tested with a dentate phantom (A) in a metal-free environment. To simulate the intraoperative environment and different anatomies, the registration procedure was also performed with an OR bed using the dentate phantom and two (partially) edentulous phantoms with atypical anatomy (B and C). The accuracy of the registration was calculated using the notches on the osteotomy planes and was expressed as the target registration error (TRE). TRE values of less than 2.0 mm were considered as clinically acceptable. RESULTS: In all experiments, the mean TRE was less than 2.0 mm. No differences were found using different surface point areas or number or configurations of surface points. Registration accuracy in the simulated intraoperative setting was-mean (SD)-0.96 (0.22), 0.93 (0.26), and 1.50 (0.28) mm for phantom A, phantom B, and phantom C. CONCLUSION: Hybrid registration is a noninvasive method that requires only a small area of the bare mandibular bone surface to obtain high accuracy in phantom setting. Future studies should test this method in clinical setting during actual surgery.

Direct discharge of patients with simple stable musculoskeletal injuries as an alternative to routine follow-up: a systematic review of the current literature.

PURPOSE: There is growing evidence that patients with certain simple stable musculoskeletal injuries can be discharged directly from the Emergency Department (ED), without compromising patient outcome and experience. This study aims to review the literature on the effects of direct discharge (DD) of simple stable musculoskeletal injuries, regarding healthcare utilization, costs, patient outcome and experience. METHODS: A systematic review was performed in Medline, Embase, CINAHL, Cochrane Library and Web of Science using PRISMA guidelines. Comparative and non-comparative studies on DD of simple stable musculoskeletal injuries from the ED in an adult/paediatric/mixed population were included if reporting ≥ 1 of: (1) logistic outcomes: DD rate (proportion of patients discharged directly); number of follow-up appointments; DD return rate; (2) costs; (3) patient outcomes/experiences: functional outcome; treatment satisfaction; adverse outcomes; other. RESULTS: Twenty-six studies were included (92% conducted in the UK). Seven studies (27%) assessed functional outcome, nine (35%) treatment satisfaction, and ten (38%) adverse outcomes. A large proportion of studies defined DD eligibility criteria as injuries being minor/simple/stable, without further detail. ED DD rate was 26.7-59.5%. Mean number of follow-up appointments was 1.00-2.08 pre-DD, vs. 0.00-0.33 post-DD. Return rate was 0.0-19.4%. Costs per patient were reduced by €69-€210 (ranging from - 38.0 to - 96.6%) post-DD. Functional outcome and treatment satisfaction levels were 'equal' or 'better' (comparative studies), and 'high' (non-comparative studies), post-DD. Adverse outcomes were low and comparable. CONCLUSIONS: This systematic review supports the idea that DD of simple stable musculoskeletal injuries from the ED provides an opportunity to reduce healthcare utilization and costs without compromising patient outcomes/experiences. To improve comparability and facilitate implementation/external validation of DD, future studies should provide detailed DD eligibility criteria, and use a standard set of outcomes. Systematic review registration number: 120779, date of first registration: 12/02/2019.

Registration methods for surgical navigation of the mandible: a systematic review.

Image-to-patient registration in navigated mandibular surgery is complex due to the mobile nature of the mandible compared with other craniofacial bones. As a result, surgical navigation is rarely employed in the mandibular region. This systematic review provides an overview of the different registration methods that are used for surgical navigation of the mandible. A systematic search was performed in the MEDLINE Ovid, Scopus, and Embase databases on March 25, 2021. Search terms included synonyms for mandibular surgery, surgical navigation, and registration methods. Articles about navigated mandibular surgery, where the registration method was explicitly mentioned, were included. The database search yielded a total of 2952 articles, from which 81 articles remained for analysis. Four main registration methods were identified: point registration, surface registration, hybrid registration, and computer vision-based registration. The mobility of the mandible is accounted for by either keeping the mandible in a fixed position during preoperative imaging and surgery, or by tracking the mandibular movements. Although different registration methods are available for navigated mandibular surgery, there is always a trade-off between accuracy, registration time, usability, and invasiveness. Future studies should focus on testing the different methods in larger patient studies and should report the registration accuracy.

Clinical outcome of CIDP one year after start of treatment: a prospective cohort study.

OBJECTIVE: To assess clinical outcome in treatment-naive patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). METHODS: We included adult treatment-naive patients participating in the prospective International CIDP Outcome Study (ICOS) that fulfilled the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria for CIDP. Patients were grouped based on initial treatment with (1) intravenous immunoglobulin (IVIg), (2) corticosteroid monotherapy or (3) IVIg and corticosteroids (combination treatment). Outcome measures included the inflammatory Rasch-built overall disability scale (I-RODS), grip strength, and Medical Research Council (MRC) sum score. Treatment response, treatment status, remissions (improved and untreated), treatment changes, and residual symptoms or deficits were assessed at 1 year. RESULTS: Forty patients were included of whom 18 (45%) initially received IVIg, 6 (15%) corticosteroids, and 16 (40%) combination treatment. Improvement on ≥ 1 of the outcome measures was seen in 31 (78%) patients. At 1 year, 19 (48%) patients were still treated and fourteen (36%) patients were in remission. Improvement was seen most frequently in patients started on IVIg (94%) and remission in those started on combination treatment (44%). Differences between groups did not reach statistical significance. Residual symptoms or deficits ranged from 25% for neuropathic pain to 96% for any sensory deficit. CONCLUSIONS: Improvement was seen in most patients. One year after the start of treatment, more than half of the patients were untreated and around one-third in remission. Residual symptoms and deficits were common regardless of treatment.

Adhesion prevention during laparotomy: long-term follow-up of a randomized clinical trial.

OBJECTIVE: The objective of the study was to determine the long-term effect of the use of a hyaluronic acid-carboxymethylcellulose membrane (Seprafilm) on the incidence of adhesions and subsequent small-bowel obstruction and chronic abdominal complaints after colorectal surgery (Hartmann's procedure). BACKGROUND: Adhesions occur frequently after abdominal surgery and are the most common cause of bowel obstruction, chronic abdominal pain, and infertility. The risk for adhesion-related readmission in the first 10 years after colorectal surgery is as high as 30%. To reduce the formation of adhesions, a mechanical barrier composed of hyaluronic acid and carboxymethylcellulose was developed, to prevent adherence of tissues after abdominal surgery. Long-term results concerning the incidence of small-bowel obstruction and chronic abdominal pain are lacking. METHODS: Between April 1996 and September 1998, 71 patients requiring Hartmann's procedure for sigmoid diverticulitis or obstructed rectosigmoid were randomized to either intraperitoneal placement of Seprafilm under the midline and in the pelvis or as a control. Direct visual evaluation of the incidence and severity of adhesions was performed laparoscopically in 42 patients at second-stage surgery for restoration of the continuity of the colon. The results of this study were published in 2002. In 2006, the patients' general practitioners were interviewed by means of a questionnaire concerning their patients' health. The patients who were still alive were interviewed and asked to fill out 2 questionnaires concerning pain and quality of life (VAS-pain score, EQ-5D, and SF-36). In 2009, the medical records of the patients were evaluated for adhesion-related hospital re-admissions. RESULTS: Of the 42 evaluated patients, 35 (16 in the Seprafilm group, 19 in the control group) could be enrolled in the long-term follow-up. Median follow-up was 126 months (range 41-148) for the Seprafilm group and 128 months (range 49-149) months for the control group. Incidence of chronic (3 months or longer existing) abdominal complaints was significantly lower in the Seprafilm group compared with controls (35.3% vs. 77.8%, respectively; P = 0.018). Incidence of small-bowel obstruction showed no significant difference in favor of the Seprafilm group; no small-bowel obstructions occurred in the Seprafilm group, whereas in the control group 2 cases of small-bowel obstruction were found to have occurred. Evaluation of the quality of life questionnaires did not reveal significant differences between the 2 groups. CONCLUSIONS: In Hartmann's procedure, Seprafilm placement does not provide protection against small-bowel obstruction. Incidence of chronic abdominal complaints is significantly lower after use of Seprafilm.

Electromagnetic surgical navigation in patients undergoing mandibular surgery.

The purpose of this study was to evaluate the feasibility of electromagnetic (EM) navigation for guidance on osteotomies in patients undergoing oncologic mandibular surgery. Preoperatively, a 3D rendered model of the mandible was constructed from diagnostic computed tomography (CT) images. Cutting guides and patient specific reconstruction plates were designed and printed for intraoperative use. Intraoperative patient registration was performed using a cone beam CT scan (CBCT). The location of the mandible was tracked with an EM sensor fixated to the mandible. The real-time location of both the mandible and a pointer were displayed on the navigation system. Accuracy measurements were performed by pinpointing four anatomical landmarks and four landmarks on the cutting guide using the pointer on the patient and comparing these locations to the corresponding locations on the CBCT. Differences between actual and virtual locations were expressed as target registration error (TRE). The procedure was performed in eleven patients. TREs were 3.2 ± 1.1 mm and 2.6 ± 1.5 mm using anatomical landmarks and landmarks on the cutting guide, respectively. The navigation procedure added on average half an hour to the duration of the surgery. This is the first study that reports on the accuracy of EM navigation in patients undergoing mandibular surgery.

Evaluating the accuracy of resection planes in mandibular surgery using a preoperative, intraoperative, and postoperative approach.

In mandibular surgery, three-dimensionally printed patient-specific cutting guides are used to translate the preoperative virtually planned resection planes to the operating room. This study was performed to determine whether cutting guides are positioned according to the virtual plan and to compare the intraoperative position of the cutting guide with the resection performed. Nine patients were included. The exact positions of the resection planes were planned virtually and a patient-specific cutting guide was designed and printed. After surgical placement of the cutting guide, intraoperative cone beam computed tomography (CBCT) was performed. Postoperative CT was used to obtain the final resection planes. Distances and yaw and pitch angles between the preoperative, intraoperative, and postoperative resection planes were calculated. Cutting guides were positioned on the mandible with millimetre accuracy. Anterior osteotomies were performed more accurately than posterior osteotomies (intraoperatively positioned and final resection planes differed by 1.2±1.0mm, 4.9±6.6°, and 1.8±1.5°, respectively, and by 2.2±0.9mm, 9.3±9°, and 8.3±6.5° respectively). Differences between intraoperatively planned and final resection planes imply a directional freedom of the saw through the saw slots. Since cutting guides are positioned with millimetre accuracy compared to the virtual plan, the design of the saw slots in the cutting guides needs improvement to allow more accurate resections.

Adoption of direct discharge of simple stable injuries amongst (orthopaedic) trauma surgeons.

INTRODUCTION: The importance of routine follow-up of several relatively simple stable injuries (SSIs) is questionable. Multiple studies show that direct discharge (DD) of patients with SSIs from the Emergency Department results in patient outcomes and experiences comparable to 'standard care' with outpatient follow-up. The purpose of this study was to evaluate to which extent DD of SSIs has been adopted amongst trauma and orthopedic surgeons internationally, and to assess the variation in the management of these common injuries. METHODS: An online survey was sent to members of an international trauma- and orthopaedic surgery collaboration. Participants, all trauma- or orthopaedic surgeons, were presented with eleven hypothetical cases of patients with simple stable injuries in which they were asked to outline their treatment plan regarding number of follow-up appointments and radiographs, physiotherapy and when to start functional movement. The primary outcome was the proportion of surgeons selecting direct discharge (i.e. zero scheduled appointments), per injury. Secondary outcomes included clinical agreement (>80% of respondents answering similarly) on total number of follow-up appointments (0, 1 or ≥2), radiographs (0, 1 or ≥2), routine physiotherapy referral (yes/no) and when to start functional movement (weeks). RESULTS: 138 of 667 (20.7%) surgeons completed the survey. Adoption of direct discharge ranged from 4-45% of case examples. In 10 out of 11 cases, less than 25% of surgeons selected direct discharge. Clinical agreement regarding number of appointments and when to start functional movement was not reached for any of the injuries. There was clinical agreement on number of radiographs for one injury and for four injuries regarding routine referral to a physiotherapist. DISCUSSION: Despite available evidence, DD of SSIs has not been widely adopted worldwide. Practice variation still exists even for these common injuries. This variation suggests inefficiency and consequently unnecessarily high healthcare costs. (Orthopaedic) trauma surgeons are encouraged to evaluate their current treatment protocols of SSIs.

Long-term follow-up evaluation of chronic pain after endoscopic total extraperitoneal repair of primary and recurrent inguinal hernia.

BACKGROUND: Long-term data on chronic pain after endoscopic total extraperitoneal (TEP) hernia repair are hardly available. METHODS: Between January 1997 and December 1998, 416 patients with consecutive primary and recurrent inguinal hernia underwent endoscopic TEP hernia repair. Long-term follow-up evaluation was carried out from June 2007 to June 2008. The primary outcome measure was persistent pain and discomfort interfering with daily activity. RESULTS: The overall response rate was 66% (273 of 416 patients). Of the 416 patients, 85 (20%) had died of causes unrelated to hernia repair and 58 (14%) were lost to follow-up. A total of 177 patients were physically examined in the outpatient clinic. Because 96 patients were not able to visit the outpatient' clinic, they completed the survey by telephone. The median follow-up period was 10 years (range, 9-11 years). After TEP repair, 16 patients (6%) reported chronic groin pain, and 10 patients (4%) still experience pain at this writing after the 10-year follow-up period. One of the patients has experienced persistent pain and discomfort interfering with daily activity. Patients with preoperative pain have reported significantly more chronic pain (P = 0.03). CONCLUSIONS: Chronic groin pain after TEP repair of primary and recurrent inguinal hernia seems to have a low incidence after a 10-year follow-up period.