Holger Keil

Comparison of Extracorporal Shock Wave Pretreatment to Classic Surgical Delay in a Random Pattern Skin Flap Model

Background: Extracorporal shock wave therapy has a significant positive effect on rescuing the ischemic zone of flap tissue if applied immediately after surgical intervention. The purpose of this study was to determine the potential preoperative effect of noninvasive extracorporal shock wave therapy to precondition flap tissue compared with the well-established surgical delay procedure. Methods: Thirty-two male Wistar rats were randomized into four groups, and an oversized, random-pattern flap was raised in each animal. In group D7, a surgical delay was carried out 1 week before full flap harvest. In group E7, the whole flap area was treated with extracorporal shock wave therapy to induce mechanical delay. Group E7D7 was treated preoperatively with a combination of surgical delay and extracorporal shock wave therapy. Group C constituted the control group, in which the skin flap was harvested without any prior intervention. Seven days after flap harvest, flap survival, perfusion, microvessel density, and vascular endothelial growth factor concentration were assessed. Results: Flap survival, perfusion, and microvessel density were significantly increased in the delay group (group D7) and the extracorporal shock wave therapy group (group E7) compared with the control group (group C). Combining both pretreatments (group E7D7) did not have a favorable cumulative effect. Vascular endothelial growth factor expression was not significantly increased in any group. Conclusions: Although not superior to surgical delay, the authors see many advantages of extracorporal shock wave therapy; it is noninvasive, easily applicable, less time- consuming, and less expensive. Thus, it may constitute an alternative procedure in clinical situations that warrant a noninvasive, fast, and easily applicable treatment.

Preoperative shock wave treatment enhances ischemic tissue survival, blood flow and angiogenesis in a rat skin flap model

INTRODUCTION Extracorporeal shock wave treatment (ESWT) has recently been shown to enhance skin flap survival. However, the bio-mechanisms operating during preoperative ESWT remain unclear. The aim of our study was to investigate whether preoperative ESWT can improve blood flow in ischemic skin flaps and to elucidate its possible mechanisms. METHODS 14 male-rats were randomized into two groups and an oversized ventral random-pattern flap was raised. Experimental group received extracorporeal shock-wave treatment (ESWT) with an energy of 500 mJ/mm(2) seven days prior to total flap elevation, while control group received no treatment prior to total flap elevation. Seven days postoperatively, surviving flap area, perfused flap area, microvessel density and VEGF concentration were measured. RESULTS Surviving flap area (59.43 ± 14.72 % to 42.71 ± 10.75 %, p = 0.026), perfused flap area (62.00 ± 8.58 % to 45.14 ± 10.50 %, p = 0.007), microvessel density (18.13 ± 5.11 to 11.09 ± 1.12, p = 0.016) and VEGF to total protein ratio (0.2107 ± 0.0935 to 0.0123 ± 0.0069, p = 0.008) were significantly elevated in the ESWT group. CONCLUSION Preoperative ESWT can improve skin flap survival through enhanced topical blood perfusion and neovascularization via elevation of angio-active factors.

Optimal Timing of Extracorporeal Shock Wave Treatment to Protect Ischemic Tissue

Enhancement of flap survival through extracorporeal shock wave treatment (ESWT) is a promising new technique; however, no attempt has been made to define the optimal time point and frequency of ESWT to optimize treatment with ESWT for ischemic indications. Twenty-eight male Wistar rats were randomized into 4 groups and an oversized, random-pattern flap was raised and reattached in place in each animal. ESWT was applied 7 days before (group E7) or immediately after the surgical intervention (group E0). The third group was treated with ESWT 7 days before and additionally immediately after the operation (group E7/0). The fourth group served as a control group and did not receive any ESWT (group C). Seven days after flap harvest the results of flap survival, perfusion, microvessel density, and vascular endothelial growth factor concentrations were assessed. Flap survival was significantly increased in all ESWT groups as compared with the control group. The groups (E7 and E0) that received ESWT pre- or postoperatively showed a significant increase in flap perfusion and microvessel density. Combined pre- and postoperative ESWT application (group E0/E7) did not demonstrate a cumulative effect in any evaluation. In this study, we were be able to prove the effectiveness of ESWT in the protection of ischemic tissue flaps. This study suggests that single postoperative application is the most efficacious protocol for clinical applications of ESWT in the treatment of ischemic tissue.

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

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.

Development and validation of a novel questionnaire for self-determination of the range of motion of wrist and elbow

BackgroundThe aim of this study was to develop and validate a novel self-administered questionnaire for assessing the patient’s own range of motion (ROM) of the wrist and the elbow.MethodsIn a prospective clinical study from January 2015 to June 2015, 101 consecutive patients were evaluated with a novel, self-administered, diagram-based, wrist motion assessment score (W-MAS) and elbow motion assessment score (E-MAS). The questionnaire was statistically evaluated for test-retest reliability, patient-physician agreement, comparison with healthy population, and influence of covariates (age, gender, affected side and involvement in workers’ compensation cases).ResultsAssessment of patient-physician agreement demonstrated almost perfect agreement (k > 0.80) with regard to six out of eight items. There was substantial agreement with regard to two items: elbow extension (k = 0.76) and pronation (k = 0.75). The assessment of the test-retest reliability revealed at least substantial agreement (k = 0.70). The questionnaire revealed a high discriminative power when comparing the healthy population with the study group (p = 0.007 or lower for every item). Age, gender, affected side and involvement in workers’ compensation cases did not in general significantly influence the patient-physician agreement for the questionnaire.ConclusionThe W-MAS and E-MAS are valid and reliable self-administered questionnaires that provide a high level of patient-physician agreement for the assessments of wrist and elbow ROM.Level of evidence: Diagnostic study, Level II