[Residency program under scrutiny-how do residents prepare for elective operations?] / Weiterbildung unter der Lupe ­ Wie bereiten sich Weiterbildungsassistenten auf elektive Operationen vor?

BACKGROUND: A wide variety of technical, emotional and organizational aspects of the residency program are aligned with "learning and teaching operations". When a resident is assigned as an operator to the operation program, many chances are provided for teaching and learning with preparation, intraoperative and postoperative care. But the moment when a resident starts preparing for an operation, heterogeneous and partly old-fashioned attitudes as well as contradictory practices must be faced in the clinical context. In the daily practice there is no consensus about a structured preparation for an operation. There have been no scientific investigations on this topic so far. METHODS: From February to April 2015 questionnaires were sent to all trauma and orthopedic surgeons in the trauma network of East Bavaria (27 clinics, 255 physicians). Using Likert scales, the participants could rate the importance of certain elements of preparation for two elective operations and the intensity of how the residents succeeded in these. The aim was to objectify if and to what extent the aspirations diverge from clinical reality. RESULTS: A total of 150 forms could be analyzed (response rate 59%). The surgical approach, patient examinations, study of patient files, discussion with the consultant and the operation technique were considered to be the most important elements; however, approximately half of the participants stated that they did not sufficiently accomplish these elements. Gender-specific differences or differences between the age groups could only be sporadically detected. CONCLUSION: A mismatch could be recognized between aspiration and reality concerning the personal preparations of residents for operations. Hospital-specific concepts and a standardized, preoperative dialogue between residents and consultants could be an important element in a successful preparation for interventions.

Percutaneous screw placement in acetabular posterior column surgery: gender differences in implant positioning.

Percutaneous reduction and periarticular screw implantation techniques have been successfully introduced in acetabular surgery. Image guided navigation techniques might be beneficial in increasing accuracy. However, a thorough understanding of standard values is needed to oversee pitfalls. This cadaver study was designed to identify reliable angulation values for screw implantation in the posterior acetabular column and to provide knowledge of the bony thickness for the periarticular corridor. Gender differences were specifically addressed. 27 embalmed cadaveric hemipelvic specimens (13 male, 14 female) were used. After soft-tissue removal posterior column acetabular screw placement was conducted by one experienced orthopaedic trauma surgeon under visibility. Radiographic verification of ideal screw placement was followed by radiographic assessment in three standard views and angulation values were assessed. Through bony dissection the maximal periarticular canal width was assessed. Various angulation values with regard to anatomical landmarks could be determined in the anteroposterior radiograph, as well as in the iliac oblique and the obturator oblique view. Gender differences were significant for all reference points with the pubic rami involved. The minimal canal width was 1.1cm in female and 1.6 cm in male specimen. The findings provide standard values for safe passages in percutaneous posterior column acetabular surgery. Gender differences have to be taken in consideration when planning the drill corridor. By adherence to standard values, screw placement can be performed safely.

Mono- versus polyaxial locking plates in distal femur fractures: a prospective randomized multicentre clinical trial.

PURPOSE: Treatment of complex fractures of the distal femur utilizing monoaxial locking plates (e.g. Less Invasive Stabilisation System, LISS®, Synthes) is considered to be superior to conventional plating systems. Due to the limitation that the thread forces the screw into pre-determined positions, modifications have been made to allow screw positioning within a range of 30° (Non Contact Bridging, NCB®-DF, Zimmer). For the first time, this multicenter prospective randomized clinical trial (RCT) investigates the outcome of LISS® vs. NCB®-DF treatment following complex fractures of the distal femur. METHODS: Since June 2008, 27 patients with a fracture of the distal femur (AO ASIF 33-A-C and periprosthetic fractures) were enrolled in this study by four university trauma centres in southern Germany. Clinical (e.g. range of motion, Oxford knee score, Tegner score) and radiological (e.g. axis deviation, secondary loss of realignment) follow-ups were conducted one and six weeks, as well as three, six, and 12 months after the operation. RESULTS: This study comprises data of 27 patients (8 male, 19 female; 15 NCB®-DF, 12 LISS®). Polyaxial osteosynthesis using the NCB® system tended to result in better functional knee scores and a higher range of motion. Interestingly, fracture union tended to be more rapid using the polyaxial plating system. CONCLUSIONS: We present the analysis of a multicenter prospective RCT to compare the monoaxial LISS® vs. the polyaxial NCB®-DF treatment following complex fractures of the distal femur. NCB®-DF treatment tended to result in better functional and radiological outcomes than LISS® treatment. LEVEL OF EVIDENCE: Level I.

Incidence and outcome of atlanto-occipital dissociation at a level 1 trauma centre: a prospective study of five cases within 5 years.

BACKGROUND: Prospective evaluation of atlanto-occipital dissociations (AODs) at a level 1 trauma centre within 5 years. METHODS: Over a period of 5 years (2005-2009), all CT scans of the skull base and the upper cervical spine due to traumatic injuries were prospectively entered into a database. Furthermore, in cases of confirmed AOD all empirical data were prospectively collected. A more detailed data analysis of all AOD patients was conducted 2 years post-trauma. If required, another prospective follow-up was performed. RESULTS: 2,616 CT scans were performed in total. Out of these, there were five male patients with confirmed AOD. Thus, the total incidence was 0.2 %. AOD was associated with occipital condyle fractures in three out of the five cases. Three out of five patients (60 %) died due to the severity of the injury. It was possible to stabilise two patients surgically with a clinical/radiological follow-up 2 years post-surgery. At that time, one patient had an incomplete tetraplegia and was wheelchair ridden without needing ventilation, while the other patient suffered from post-traumatic stress disorder, but was able to walk and live alone. CONCLUSIONS: AOD is a rarely seen injury, even in a level 1 trauma centre, and is associated with high morbidity and mortality. However, it is possible for adults to survive this severe occipito-cervical injury after surgical repair while maintaining the ability to walk. All the results and recommendations are still based on a low level of evidence, due to the low incidence of this injury.

Screw placement in percutaneous acetabular surgery: gender differences of anatomical landmarks in a cadaveric study.

PURPOSE: Percutaneous reduction and periarticular screw implantation techniques have been successfully introduced in acetabular surgery. The advantages of this less invasive approach are attenuated by higher risks of screw misplacement. Anatomical landmarks are strongly needed to prevent malplacement. This cadaver study was designed to identify reliable anatomical osseous landmarks in the pelvic region for screw placement in acetabular surgery. Gender differences were specifically addressed. METHODS: Twenty-seven embalmed cadaveric hemipelvic specimens (13 male, 14 female) were used. After soft-tissue removal, anterior and posterior column acetabular screw placement was conducted by one orthopaedic trauma surgeon under direct vision. Each column was addressed by antegrade and retrograde screw insertion. Radiographic verification of ideal screw placement was followed by assessment of the distance from the different entry points to adjoining anatomical osseous structures. RESULTS: For anterior column screw positioning, the posterior superior iliac spine (PSIS), posterior inferior iliac spine (PIIS), iliopectineal eminence and centre of the symphysis were most reliable regarding gender differences. For posterior column screw positioning, the distance to the anterior superior iliac spine (ASIS) and the ischial tuberosity showed the lowest deviation between the different gender specimens. Highest gender differences were seen in relation to the cranial rim of the superior pubic ramus in retrograde anterior column screw positioning (p = 0.002). Most landmarks could be targeted within a 2.5-cm range in all specimens. CONCLUSIONS: The findings emphasise the relevance of osseous landmarks in acetabular surgery. By adhering to easily identifiable structures, screw placement can be safely performed. Significant gender differences must be taken into consideration during preoperative planning.

Occipital condyle fractures. Prospective follow-up of 31 cases within 5 years at a level 1 trauma centre.

PURPOSE: Prospective investigation of incidence and outcome of occipital condyle fractures (OCF) in a level 1 trauma centre. METHODS: Over a period of 5 years, we prospectively recorded all cases of OCF, and performed a 1-year post-injury radiological and clinical follow-up using CT imaging, SF-36 and Neck Disability Index, respectively. RESULTS: A total of 31 patients with OCF were identified. Based on a total of 2,616 CT scans that had been performed during this period, the incidence was 1.19%. There were 27 unilateral and 4 bilateral OCFs. Furthermore, 3 out of 31 patients (9.7%) were additionally diagnosed with atlanto-occipital dislocation (AOD), one of which was dorsally stabilised in a surgical procedure. All other patients were treated conservatively. 5 out of 31 patients (16.1%) died due to the severity of associated injuries. 22 out of 31 patients (70.9%) were prospectively followed-up for 1 year after trauma. During this period, CT imaging showed bony consolidation of fractures in all cases except for one, with no evidence of secondary dislocation or nonunion. Evaluation of the Neck Disability Index showed moderate disability. The SF-36 questionnaire showed an impaired quality of life in all areas; however, these were determined by associated injuries and independent of the type of fracture. CONCLUSIONS: Both unilateral and bilateral OCFs represent a stable injury regardless of the type of fracture. If AOD has been diagnosed in addition, it requires surgical stabilisation-independent of the OCF-and it is a significant predictor for poor outcomes. The patients quality of life 1 year after trauma has not been affected by the OCF, but by the overall pattern of the injury and by comorbidities. Based on our results, we introduce a new, simple and practical classification for OCFs.

A minimally invasive stabilizing system for dorsal pelvic ring injuries.

BACKGROUND: Open reduction and stabilization of dorsal pelvic ring injuries is accompanied by a high rate of soft tissue complications. Minimally invasive techniques have the potential to decrease soft tissue trauma, but the risk of iatrogenic nerve and vessel damage through the reduced surgical exposure should be considered. We treated these injuries using a transiliac internal fixator (TIFI) in a minimally invasive technique characterized by implantation of a pedicle screw and rod system, bridging the sacroiliac joints and the sacral area. QUESTIONS/PURPOSES: We asked whether (1) we could achieve anatomic restoration with the device, (2) specific complications were associated with this minimally invasive approach (particularly enhanced intraoperative blood loss, soft tissue complications, and iatrogenic neurovascular damage), and (3) function 3 years after trauma was comparable to that of established methods. METHODS: We retrospectively reviewed 67 patients with dorsal pelvic injuries during a 7-year period. We evaluated the (1) reduction by grading the maximal displacement measured with three radiographic views, (2) the complications during the observation period, and (3) the function with a validated questionnaire (Pelvic Outcome Score) in all but five patients at least 3 years after trauma (mean, 37 months; range, 36-42 months). RESULTS: At last followup we observed a secondary fracture displacement greater than 5 mm in one patient. The intraoperative blood loss was less than 50 mL in all patients. No neurovascular lesions occurred owing to implantation. Four patients had wound infections, one had loosening of a single pedicle screw, and one had an iatrogenic screw malpositioning. Thirty-five of the 62 patients achieved Pelvic Outcome Scores of either a maximum score or 6 of 7 points. CONCLUSION: Our observations suggest TIFI is a reasonable alternative to other established fixation devices for injuries of the dorsal pelvic ring with minor risks of major blood loss or iatrogenic neurovascular damage. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Biomechanical analysis of a transiliac internal fixator.

PURPOSE: We evaluated the biomechanical characteristics of the transiliac internal fixator (TIFI) as compared to two well-established methods of internal posterior pelvic ring fixation. METHODS: Six freshly frozen human pelves were used for simulated single-leg stance loading of an AO type C injury model (pubic symphysis diastasis and unilateral sacroiliac joint disruption). The symphysis rupture was stabilized with a dynamic compression plate. Afterwards the three internal stabilization systems (TIFI, iliosacral screws and ventral plate osteosynthesis) were analysed. Fragment movement was measured in a contact-free manner with a stereophotometric infrared system. RESULTS: No significant differences in the three-dimensional deformation tolerated by the TIFI as compared to the other internal fixation systems were found. CONCLUSIONS: The transiliac internal fixator provides the same biomechanical stability as the other reference implants tested. We suggest the use of this device as a suitable alternative to the other implants.

Arthroplasty of the lunate using bone marrow mesenchymal stromal cells.

Mesenchymal stromal cells have the potential to differentiate into a variety of mesenchymal tissues such as bone, cartilage and ligaments. The potential for the regeneration of bone with cartilage coverage has still not been achieved. We evaluated the ability of bone marrow mesenchymal stromal cells to regenerate osteochondral defects in the cavity of the lunate in an animal model. Autologous mesenchymal stromal cells were harvested from the iliac crest of New Zealand white rabbits and expanded in vitro. Total lunate excision was performed in 24 animals and the isolated cells were loaded onto scaffolds. Cell-free scaffolds were implanted in the lunate space of the right wrists of all animals, and the left lunate spaces were filled with predifferentiated, cell-loaded scaffolds. Radiographic and histological analyses were performed after two, six and 12 weeks. In addition, the animals were injected with a fluorescent agent every five days, starting at day 30. After two and six weeks there was no radiographic evidence of ossification, whereas after 12 weeks all animals showed radiographic evidence of ossification. Histological sections showed increasing evidence of cartilage-like cell formation at the edges and new bone tissue in the centre of the newly formed tissue in all groups. The histological examinations showed that bone tissue was located around the newly incorporated vascularisation. This study demonstrated that newly formed vascularisation is necessary for the regeneration of bone tissue with cell-loaded scaffolds.

The use of 'fasciocutaneous' and 'osteofasciocutaneous' parascapular flaps for lower limb reconstruction: a retrospective study of 20 patients.

BACKGROUND: The parascapular flap is a widely accepted and suitable option for covering defects in almost all anatomical areas. Here, we report our experience with the microvascular transfer of parascapular flaps for the coverage of large lower leg defects with reference to our retrospective study. PATIENTS AND METHODS: Twenty patients with free parascapular flaps (17 male, three female, age: 43+/-17 years, BMI 26.1+/-3.5) were examined 3 months to 3 years after free tissue transfer. All procedures and examinations were performed by the same experienced surgeon (2002-2005). Flap dimensions ranged from 8 x 4 cm to 30 x 13 cm, with an average of 20.4+/-6.6 cm x 8.9+/-2.6 cm. The parameters studied included perioperative morbidity, donor site morbidity, flap vitality, complications, functional shoulder tests, patient satisfaction (visual analog scale, VAS), the duration of the hospital stay and the long-term outcome. RESULTS: All of the 20 flaps remained vital. Adequate coverage and complete healing were obtained in all patients during the follow-up period and all patients were physically mobile. General patient satisfaction with the intervention was high (VAS: median 7.5; x(25)=6.0; x(75)=9.5); donor site morbidity was low, that is, only one patient presented with reduced range of motion and shoulder function compared to the preoperative status. The hospital stay after flap transfer was 20.8+/-9.8 days and the overall hospital stay was 32.1+/-15.0 days. CONCLUSIONS: Our study confirms that the parascapular flap is a very versatile and safe flap for lower limb reconstruction with low donor morbidity.

Development of a robotic navigation and fracture fixation system.

The use of robotics in surgery is nothing new. However, there are areas of surgery, such as in fracture fixation, where robots have yet to be implemented. This paper considers the choice of robot, gripper and ancillary equipment together with navigation systems necessary for their application. Hitherto robots have seen operation in surgery only in cases where relatively low manipulation forces are required. Nothing yet exists with the capability of handling forces in excess of 200 Newton as would be required in the above scenario. Another encumbrance to robots which are already in medical use is the difficulty in programming. Unfortunately most of these robots are programmed by specialists for a particular application. However, there exists a number of robot programming languages, like Unimation VA-LII (recently superceded by Stäubli V+), which do not require specialist knowledge. The application of industrial robots to the "heavier" side of modern surgery is without doubt technically realisable. The remainder of this research project aims to determine exactly which robots and what ancilliary equipment are needed and then to implement them, first on plastic models and later on cadavers. A second phase is expected to deal with type approval and a final third phase with operations on live patients.