Benedict Swartman

Long-term outcome of femoral derotation osteotomy in children with spastic diplegia

Satisfactory short-term results after femoral derotation osteotomy (FDO) for the treatment of internal rotation gait in cerebral palsy have been reported by various authors. However, there are only a few longer-term studies reporting results 5 years after FDO and these are not in agreement. There are no reports on the clinical course beyond the pubertal growth spurt. 33 children with diplegia (n=59 legs, age: 10.5±3.6 years) and internally rotated gait were examined pre- (E0), 1 year (E1), 3±1 (E2) and 9±2 (E3) years after distal (27 legs) or proximal (32 legs) FDO as part of multilevel surgery, using standardized clinical exam and 3D gait-analysis at all examinations. The amount of intra-operative derotation averaged 25°. ANOVA was used for statistics (p<0.05). Mean hip internal rotation in stance at E0 of 17.3° was significantly changed to 1.0° of external rotation at E1 and was maintained at 4.2° at E3. The same clinical course was found for foot progression angle. The mid-point of passive hip rotation at E0 was 21°. This was significantly decreased to 6° at E1 and showed a small but significant increase reaching 12° at E3. The results of this study showed a good overall correction of internally rotated gait following FDO. These improvements were maintained at long-term follow-up after the pubertal growth spurt. Recurrence was observed in some cases with overall severe deterioration. In those patients persistent dynamic factors leading to recurrence should be further investigated.

Management of syndesmotic injuries: What is the evidence?

Ankle fractures are accompanied by a syndesmotic injury in about 10% of operatively treated ankle fractures. Usually, the total rupture of the syndesmotic ligaments with an external rotation force is associated with a Weber type B or C fracture or a Maisonneuve fracture. The clinical assessment should consist of a comprehensive history including mechanism of injury followed by a specific physical examination. Radiographs, and if in doubt magnetic resonance imaging, are needed to ascertain the syndesmotic injury. In the case of operative treatment the method of fixation, the height and number of screws and the need for hardware removal are still under discussion. Furthermore, intraoperative assessment of the accuracy of reduction of the fibula in the incisura using fluoroscopy is difficult. A possible solution might be the assessment with intraoperative three-dimensional imaging. The aim of this article is to provide a current concepts review of the clinical presentation, diagnosis and treatment of syndesmotic injuries.

Long-term results after non-operative and operative treatment of radial neck fractures in adults

BackgroundThe aim of this study is to determine the functional long-term outcome after non-operative and operative treatment of radial neck fractures in adults.MethodsThirty-four consecutive patients with a mean age of 46.4 (18.0 to 63.0) years with a fracture of the radial neck who were treated between 2000 and 2014 were examined regarding the clinical and radiological outcome. Twenty patients were treated non-operatively, and 14 patients underwent surgery.ResultsAfter a mean follow-up of 5.7 (2.0 to 15.7) years, the clinical scores showed good results in both groups. The Disabilities of Arm, Shoulder and Hand score was 16.1 (0 to 71.6) in the non-operative group and 8.8 (0 to 50.8) in the operative group, respectively. The Mayo Elbow Performance Score was 80.0 (30 to 95) in the non-operative group and 82.5 (35 to 95) in the non-operative group, respectively. The initial angle of the radial head towards the shaft (RHSA) was significantly higher in the operative group in the anterior-posterior plane (12.8° [2 to 23] vs. 26.3° [1 to 90], p = 0.015). In the follow-up radiographs, the RHSA was significantly lower in the operative group (15.1° [3 to 30] vs. 10.9° [3 to 18], p = 0.043). Five patients developed 7 complications in the non-operative group, and 7 patients developed 12 complications in the operative group. Revision rates were higher in the operative groups as 1 patient received radial head resection in the non-operative (5%) group while 7 patients in the operative group (50%) needed revision surgery.ConclusionA good functional long-term outcome can be expected after operative and non-operative treatment of radial neck fractures in adults. If needed due to major displacement, open reduction is associated with a higher risk of complications and the need for revision surgery but can achieve similar clinical results.Trial registrationDRKS DRKS00012836 (retrospectively registered)

Virtual guidance versus virtual implant planning system in the treatment of distal radius fractures

A virtual guidance framework is used to assist the conventional method of virtual implant planning system (VIPS). The study null hypothesis was that its screw placement accuracy is equal to that of conventional VIPS.

Wire Placement in the Sustentaculum Tali Using a 2D Projection-Based Software Application for Mobile C-Arms: Cadaveric Study

Background: Indirect screw fixation of the sustentaculum tali in the lateral-medial direction can be challenging due to the complex calcaneal anatomy. A novel 2-dimensional (2D) projection-based software application detects Kirschner wires (K-wires) and visualizes their intended direction as a colored trajectory. The aim of this prospectively randomized cadaver study was to investigate whether the software would facilitate the indirect K-wire placement in the sustentaculum tali. Methods: In 20 cadaver foot specimens, K-wires were placed indirectly in the sustentaculum tali by an experienced and an inexperienced surgeon, with and without using the application. Number of placement attempts, duration of procedure, fluoroscopy time, and number of individual fluoroscopy images were recorded. Each wire’s position was analyzed in a 3-dimensional (3D) C-arm scan by an experienced blinded investigator. Results: Use of the software by the inexperienced surgeon significantly reduced the number of placement attempts from 3.2 to 1.2 (P = .006). The application also reduced operating time, from 273 s to 199 s (P = .15), and fluoroscopy time, from 41 s to 29 s (P = .15). Using the software, the experienced surgeon had a longer operating time (139 s to 183 s; P = .30), longer fluoroscopy time (5.6 s to 9.2 s; P = .17), and more individual fluoroscopy images (11.6 to 14.8; P = .30). Wire position did not show significant differences in both cases. Conclusion: During indirect K-wire placement in the sustentaculum tali, the software appeared to be a useful tool for the inexperienced surgeon. In our chosen study setting, the experienced surgeon did not benefit from the software. Clinical Relevance: Possible indications for the software would be fractures of the proximal femur, sacrum, sacroiliac instabilities, vertebral bodies, scaphoid, Lisfranc joint, talus and calcaneus.

Intra-operative imaging in trauma surgery

The reconstruction of anatomical joint surfaces, limb alignment and rotational orientation are crucial in the treatment of fractures in terms of preservation of function and range of motion. To assess reduction and implant position intra-operatively, mobile C-arms are mandatory to immediately and continuously control these parameters. Usually, these devices are operated by OR staff or radiology technicians and assessed by the surgeon who is performing the procedure. Moreover, due to special objectives in the intra-operative setting, the situation cannot be compared with standard radiological image acquisition. Thus, surgeons need to be trained and educated to ensure correct technical conduct and interpretation of radiographs. It is essential to know the standard views of the joints and long bones and how to position the patient and C-arm in order to acquire these views. Additionally, the operating field must remain sterile, and the radiation exposure of the patient and staff must be kept as low as possible. In some situations, especially when reconstructing complex joint fractures or spinal injuries, complete evaluation of critical aspects of the surgical results is limited in two-dimensional views and fluoroscopy. Intra-operative three-dimensional imaging using special C-arms offers a valuable opportunity to improve intra-operative assessment and thus patient outcome. In this article, common fracture situations in trauma surgery as well as special circumstances that the surgeon may encounter are addressed. Cite this article: EFORT Open Rev 2018;3:541-549. DOI: 10.1302/2058-5241.3.170074

Upper ankle joint space detection on low contrast intraoperative fluoroscopic C-arm projections

Intraoperative mobile C-arm fluoroscopy is widely used for interventional verification in trauma surgery, high flexibility combined with low cost being the main advantages of the method. However, the lack of global device-to- patient orientation is challenging, when comparing the acquired data to other intrapatient datasets. In upper ankle joint fracture reduction accompanied with an unstable syndesmosis, a comparison to the unfractured contralateral site is helpful for verification of the reduction result. To reduce dose and operation time, our approach aims at the comparison of single projections of the unfractured ankle with volumetric images of the reduced fracture. For precise assessment, a pre-alignment of both datasets is a crucial step. We propose a contour extraction pipeline to estimate the joint space location for a prealignment of fluoroscopic C-arm projections containing the upper ankle joint. A quadtree-based hierarchical variance comparison extracts potential feature points and a Hough transform is applied to identify bone shaft lines together with the tibiotalar joint space. By using this information we can define the coarse orientation of the projections independent from the ankle pose during acquisition in order to align those images to the volume of the fractured ankle. The proposed method was evaluated on thirteen cadaveric datasets consisting of 100 projections each with manually adjusted image planes by three trauma surgeons. The results show that the method can be used to detect the joint space orientation. The correlation between angle deviation and anatomical projection direction gives valuable input on the acquisition direction for future clinical experiments.

2D projection-based software application for mobile C-arms optimises wire placement in the proximal femur – An experimental study

PURPOSE A new software application can be used without fixed reference markers or a registration process in wire placement. The aim was to compare placement of Kirschner wires (K-wires) into the proximal femur with the software application versus the conventional method without guiding. As study hypothesis, we assumed less placement attempts, shorter procedure time and shorter fluoroscopy time using the software. The same precision inside a proximal femur bone model using the software application was premised. METHODS The software detects a K-wire within the 2D fluoroscopic image. By evaluating its direction and tip location, it superimposes a trajectory on the image, visualizing the intended direction of the K-wire. The K-wire was positioned in 20 artificial bones with the use of software by one surgeon; 20 bones served as conventional controls. A brass thumb tack was placed into the femoral head and its tip targeted with the wire. Number of placement attempts, duration of the procedure, duration of fluoroscopy time and distance to the target in a postoperative 3D scan were recorded. RESULTS Compared with the conventional method, use of the application showed fewer attempts for optimal wire placement (p=0.026), shorter duration of surgery (p=0.004), shorter fluoroscopy time (p=0.024) and higher precision (p=0.018). Final wire position was achieved in the first attempt in 17 out of 20 cases with the software and in 9 out of 20 cases with the conventional method. CONCLUSIONS The study hypothesis was confirmed. The new application optimised the process of K-wire placement in the proximal femur in an artificial bone model while also improving precision. Benefits lie especially in the reduction of placement attempts and reduction of fluoroscopy time under the aspect of radiation protection. The software runs on a conventional image intensifier and can therefore be easily integrated into the daily surgical routine.

Abstract: Detektion des tibiotalaren Gelenkspaltes in intraoperativen C-Bogen Projektionen

Bei circa 11% aller Frakturen des oberen Sprunggelenks (OSG) treten akute Verletzungen der Syndesmose auf, die aufgrund ihrer Instabilitat einen operativen Eingriff erfordern [1]. Dabei kann die Stabilisierung mittels Stellschraube zu einer Fehlstellung der Fibula fuhren, welche ohne Korrektur mit einer Verschlechterung der Lebensqualitat des Patienten einhergehen kann. Der Einsatz mobiler 3D C-Bogen ermoglicht eine raumliche Interpretation der Anatomie bei der Verifikation des Repositionsergebnisses. Gleichzeitig stellt die variable Ausrichtung des Scanners zum Patienten eine grose Herausforderung beim Vergleich mit anderen Datensatzen dar. Bei der Beurteilung von OSG Frakturen mit Beteiligung der Syndesmose kann ein Vergleich mit der gesunden Gegenseite sinnvoll sein. Da ein weiterer Scan jedoch zusatzliche Strahlenbelastung sowie eine Erhohung der Operationsdauer bedeutet, sollen stattdessen Einzelprojektionen der gesunden Gegenseite analysiert werden. In der vorliegenden Arbeit wird die Ausrichtung des Datensatzes durch die Detektion des tibiotalaren Gelenkspaltes bestimmt [2]. Ein Quadtree-basierter hierarchischer Varianzvergleich identifiziert potentielle Konturpunkte. Aus diesen werden dann mit Hilfe von Hough Transformationen Schaftkonturen und der Gelenkspalt extrahiert. Die Methode wurde auf 13 C-Bogen Datensatzen mit jeweils 100 Einzelprojektionen angewandt. Dazu wurden die anatomischen Sichtebenen von jeweils drei Unfallchirurgen manuell eingestellt, auf die Einzelprojektionen projiziert und mit den berechneten Ebenen verglichen. Die resultierende Korrelation zwischen Winkelabweichung und korrespondierendem Winkel gibt Aufschluss uber bevorzugte Aufnahmerichtungen und dient als Basis fur weiterfuhrende klinische Experimente