Norbert Suhm

Fluoroscopic guidance versus surgical navigation for distal locking of intramedullary implants a prospective, controlled clinical study

A prospective controlled clinical study was performed to compare fluoroscopic guidance with fluoroscopy-based surgical navigation for distal locking of intramedullary implants. Forty-two patients with fractures of the lower extremity treated by intramedullary nailing were divided in two groups: distal locking either with fluoroscopic guidance (group I) or with surgical navigation (group II). The average fluoroscopic time to insert one interlocking screw with fluoroscopic guidance was 108 s compared with 7.3s in the navigation group. The average procedure time to insert one interlocking screw in group I was 13.7 min compared with 17.9 min in group II. The drill bit failed to pass through the interlocking hole in one patient from group II. There was no significant difference in the technical reliability between both groups. Fluoroscopic times to achieve equivalent precision are reduced with fluoroscopy-based surgical navigation compared with fluoroscopic guidance. Fluoroscopy-based surgical navigation is recommended for intraoperative guidance in situations where reduction of exposure to radiation is considered advantageous over the increase of procedure time.

Posterior pelvic ring fractures: Closed reduction and percutaneous CT-guided sacroiliac screw fixation

PurposeTo assess the midterm results of closed reduction and percutaneous fixation (CRPF) with computed tomography (CT)-guided sacroiliac screw fixation in longitudinal posterior pelvic ring fractures.MethodsThirteen patients with 15 fractures were treated. Eleven patients received a unilateral, two a bilateral, screw fixation. Twenty-seven screws were implanted. Continuous on-table traction was used in six cases. Mean radiological follow-up was 13 months.ResultsTwenty-five (93%) screws were placed correctly. There was no impingement of screws on neurovascular structures. Union occurred in 12 (80%), delayed union in 2 (13%), and nonunion in 1 of 15 (7%) fractures. There was one screw breakage and two axial dislocations.ConclusionSacroiliac CRPF of longitudinal fractures of the posterior pelvic ring is technically simple, minimally invasive, well localized, and stable. It should be done by an interventional/surgical team. CT is an excellent guiding modality. Closed reduction may be a problem and succeeds best when performed as early as possible.

A whole-body registration-free navigation system for image-guided surgery and interventional radiology.

RATIONALE AND OBJECTIVES To develop and test an image-guided navigation system in which the base of reference is taken from the imaging modality, here, a helical CT scanner. METHODS An optical digitizer together with a calibration device is used to measure the transformation matrix between the digitizer reference system and a CT reference system. During intervention, it tracks radiological and surgical tools with tool references. A specific software visually integrates the current tool position with the corresponding image information. In vitro accuracy tests were performed. RESULTS With helical CT, freehand positioning accuracy was 1.9 +/- 1.1 mm (mean +/- SD) in vitro (n = 718). CONCLUSIONS The navigation system developed by the authors appears to be feasible for radiological interventions as well as for minimally invasive surgery. It is not limited to a certain procedure, can be used in every region of the body, and is functional after imaging. Intraprocedural scans can be integrated immediately.

Literature review of outcome parameters used in studies of Geriatric Fracture Centers.

IntroductionA variety of multidisciplinary treatment models have been described to improve outcome after osteoporotic hip fractures. There is a tendency toward better outcomes after implementation of the most sophisticated model with a shared leadership for orthopedic surgeons and geriatricians; the Geriatric Fracture Center. The purpose of this review is to evaluate the use of outcome parameters in published literature on the Geriatric Fracture Center evaluation studies.Materials and methodsA literature search was performed using Medline and the Cochrane Library to identify Geriatric Fracture Center evaluation studies. The outcome parameters used in the included studies were evaluated.ResultsA total of 16 outcome parameters were used in 11 studies to evaluate patient outcome in 8 different Geriatric Fracture Centers. Two of these outcome parameters are patient-reported outcome measures and 14 outcome parameters were objective measures.ConclusionIn-hospital mortality, length of stay, time to surgery, place of residence and complication rate are the most frequently used outcome parameters. The patient-reported outcomes included activities of daily living and mobility scores. There is a need for generally agreed upon outcome measures to facilitate comparison of different care models.

Trabecular Bone Analysis in CT and X-Ray Images of the Proximal Femur for the Assessment of Local Bone Quality

Currently, conventional X-ray and CT images as well as invasive methods performed during the surgical intervention are used to judge the local quality of a fractured proximal femur. However, these approaches are either dependent on the surgeons experience or cannot assist diagnostic and planning tasks preoperatively. Therefore, in this work a method for the individual analysis of local bone quality in the proximal femur based on model-based analysis of CT- and X-ray images of femur specimen will be proposed. A combined representation of shape and spatial intensity distribution of an object and different statistical approaches for dimensionality reduction are used to create a statistical appearance model in order to assess the local bone quality in CT and X-ray images. The developed algorithms are tested and evaluated on 28 femur specimen. It will be shown that the tools and algorithms presented herein are highly adequate to automatically and objectively predict bone mineral density values as well as a biomechanical parameter of the bone that can be measured intraoperatively.

Hip fracture management, before and beyond surgery and medication: a synthesis of the evidence

IntroductionThe geriatrician and orthopedic surgeon’s roles are well defined in hip fracture management, yet other health-care providers contribute significantly toward care, as well as maximizing rehabilitation potential and decreasing readmissions. We examine evidence concerning pre-hospital care, pain management, multidisciplinary rehabilitation and secondary prevention strategies.MethodsCochrane reviews and randomized controlled trials were identified through PubMed to synthesize current evidence in the role of multidisciplinary management of the patient with a hip fracture from injury to secondary prevention. The well-recognized roles of the geriatrician, anesthetist and orthopedic surgeon were not evaluated for the purpose of this review.ResultsTransport of patients with a hip fracture can be eased through non-pharmaceutical simple, inexpensive techniques. Nerve blockade appears effective and easily administered in the emergency department. In-hospital multidisciplinary rehabilitation programs are effective in both earlier discharge and reducing falls, morbidity and mortality. Fall prevention programs are effective in nursing home patients, but not community dwellers. Osteoporosis prevention is primarily a medical endeavor; however, exercise and education may contribute to increased bone mineral density, compliance and better results of treatment.ConclusionMultidisciplinary medical management of patients with hip fractures is being improved within the hospital environment resulting in earlier discharge with decreased morbidity. There is evidence to show the benefits to patients with hip fractures from peripheral modalities within the hospital; however unless resident in a facility, multidisciplinary management is not clearly of benefit.

Technologieintegration und Prozessmanagement Konzept und Implementierung einer neuartigen Plattform für einzeitige Diagnostik und Therapie des akut Kranken und Verletzten sowie für elektive computerassistierte Chirurgie (CAS)

ZusammenfassungModerne Bildgebung und Computertechnologie gewinnen innerhalb der Chirurgie einen immer höheren Stellenwert. Dies gilt sowohl für die elektive Chirurgie als auch für die Notfallbehandlung. Die Integration der Technologien und die dadurch mögliche Optimierung der Prozessabläufe hinken dieser Entwicklung jedoch stark hinterher. Eine neue diagnostisch-therapeutische Plattform soll dieses Defizit wettmachen. Die Plattform besteht aus einer voll ausgebauten Operationssaalumgebung mit integrierter navigationsfähiger Computertomographie, einer Angiographieanlage und einem speziell dafür entwickelten Patiententisch. Sie dient sowohl der elektiven Diagnostik als auch der Diagnostik und Therapie polytraumatisierter Patienten an einem Ort (“one stop shop”) und der computerassisitierten Chirurgie (CAS). Indem die Technologie zum Patienten und nicht der Patient zur Technologie gebracht wird, können zeitraubende, potenziell gefährliche Transporte und Umlagerungen sowie teures Personal eingespart werden. Navigationstechnologie und hochauflösende intraoperative Bildgebung erweitern das Spektrum der minimal invasiven Chirurgie.AbstractModern imaging and computer technology gain more and more importance in surgery. This is true for elective and emergency diagnosis and treatment. However integration of technology and optimization of process management is severely behind. A new diagnostic-therapeutic platform should balance this deficit. The platform is composed of a fully equipped operation room environment with integrated high end computer-tomography with navigation, a digital subtraction angiography and an OR- and imaging-table particularly developed for this set-up. The platform may be used for elective diagnosis, for diagnosis and therapy in polytraumatized patients in one and the same location (one stop shop) and for computer assisted surgery (CAS). Bringing the technology to the patient and not the patient to the technology can save time consuming and potentially dangerous transports and expensive personnel can be reduced. Navigation-technology and high quality intra-operative imaging expand the spectrum of minimally invasive surgery.

Injectable bone cement augmentation for the treatment of distal radius fractures : a review

Fractures of the distal radius often occur as a result of low-energy trauma and are frequently seen in osteoporotic patients. Many biomechanical studies and clinical case series have been carried out to investigate the effects on the fractured bones of different fixation methods such as cast immobilization, percutaneous pins, external fixators, or open reduction with internal fixation. In addition, the use of different bone cements as stand-alone solutions or as an adjunct to the aforementioned fixation methods is described as one possible way of increasing the performance of the fixation by reducing secondary dislocation of the fragments and allowing more intensive rehabilitation of the patients. This review aims to provide an overview of some of the main issues under discussion and a critical evaluation of the different treatments.

Pubic rami fractures in the elderly--a neglected injury?

OBJECTIVE To evaluate the patient characteristics and natural history of pubic rami fractures in geriatric patients, with a special focus on the frequency of concomitant posterior pelvic ring lesions and the percentage of secondarily operated patients as a result of conservative treatment failure. STUDY DESIGN Retrospective cohort study. Patients were treated in a university hospital that is equivalent to a level I Trauma centre. PATIENTS AND METHODS We analysed 132 consecutive patients (113 women, 19 men), >65 years old, presenting with low energy-trauma pubic rami fractures at our emergency department from January 2009 to December 2011. RESULTS Mean age of patients was 84 years (range 66-100). Women were affected six times more frequently than men. Almost 30% of patients lost their previous independence permanently owing to the injury. Ninety eight percent of previously independent patients (community dwellers) required temporary hospital care for a median duration of 39 days (interquartile range [IQR] 28-52). One-year mortality was 18.5%. A concomitant posterior pelvic ring lesion was identified by computed tomography in 54% of patients. In 4% of the patients secondary operative fracture stabilisation was performed. DISCUSSION Pubic rami fractures are frequently associated with concomitant posterior pelvic ring injuries, making these injuries more unstable than generally assumed. Based on this fact and the long duration of hospital stay, more aggressive management of these injuries may be considered. The principle aims in this patient population are satisfying pain management, early mobilisation, conservation of independence and return to previous place of residence.

Navigating the fluoroscope's C-arm back into position: an accurate and practicable solution to cut radiation and optimize intraoperative workflow.

Objectives: During complex image-guided orthopedic trauma procedures, repetitive fluoroscopic scout imaging is performed. A number of preparatory positioning images often must be taken to reproduce a comparable projection. These scout images have no intrinsic clinical relevance but nevertheless expose the patient and the surgical team to considerable radiation, which could be avoided. This study presents and validates a method to decrease intraoperative radiation. Methods: Precision, time requirements, and number of scout images for repositioning the fluoroscope, with and without navigation aid, were recorded on 20 test-rig and 3 phantom setups. A commercially available image-guided surgical navigation system (Vector Vision®, BrainLAB), originally designed for instrument navigation, was employed to register and retrieve the C-arm positions. A newly developed software computed the necessary moves to reposition the C-arm on an intuitive visual display. Results: Retrieving a given C-arm position with the conventional non-navigated technique required an average of 7 scout images (range, 3 to 12 images). In contrast, navigation-assisted repositioning did not necessitate a single scout image. Deviations from the original projection were minimal for both navigated (0.9 degrees, 95% CI 0.8 to 1.1 degrees) and non-navigated repositioning (0.8 degrees, 95% CI 0.7 to 0.9 degrees). Average positioning times were comparable when navigating the C-arm (46 seconds, 95% CI 41 to 51 seconds) and in scout image-based positioning (49 seconds, 95% CI 44 to 53 seconds). Conclusions: Navigated C-arm positioning avoids multiple scout images and yields sufficient precision for clinical deployment. Radiation exposure can be reduced considerably by a combination of instrument navigation and navigated C-arm positioning.