The effect of an infra-acetabular screw for anatomically shaped three-dimensional plate or standard plate designs in acetabulum fractures: a biomechanical analysis.

BACKGROUND: Various plate shapes and implant configurations are used for stabilization of acetabulum fractures via anterior approaches. Little is known about the biomechanical stability of a two-dimensionally shaped "conventional" plate ("J-Plate"-JP) in comparison to three-dimensionally shaped plate configurations (3DP). In addition, the augmentary effect of an infra-acetabular lag-screw (IACS) fixation for anterior column and posterior hemi-transverse acetabulum fractures has not been clarified in comparison of JP and 3DP constructs. This study analyzed the difference between the biomechanical stability of JP compared to 3DP and the role of an IACS in a standardized acetabular fracture model in a single-leg stance loading configuration. METHODS: In an artificial bone substitute pelvis model (Synbone© Malans, Switzerland), a typical and standardized fracture pattern (anterior column and posterior hemi-transverse) was created with osteotomy jigs. After anatomic reduction the stabilization was performed using JP or 3DP. Eight pelvises per group were axially loaded in a single-leg stance model up to 400 N. After the load cycle, an additional infra-acetabular screw was placed and the measurement repeated. Fragment displacement was recorded by an optical tracking system (Optitrack Prime 13®, Corvallis, USA). RESULTS: In the pure placement, 3DP provided significantly superior stability when compared to JP. Augmentation of JP by IACS increased the stability significantly, up to the level of 3DP alone, whereas augmentation of the 3DP did not result in further increase of overall stability. CONCLUSION: The anatomically shaped plate alone provides a superior biomechanical stability in fixation of an anterior column and posterior hemi-transverse fracture model. In a JP fixation the augmentation by IACS provides similar strength as the anatomically shaped 3DP. By use of the anatomically shaped 3DP the need of a clinically risky application of IACS might be avoidable. LEVEL OF EVIDENCE: IV, Experimental study.

Current status of anti-inflammatory therapy for posttraumatic osteoarthritis.

Although there is ample evidence that intra-articular injuries are associated with the up-regulation of pro-inflammatory cytokines, the success of anti-inflammatory, disease-modifying treatments to prevent posttraumatic osteoarthritis (PTOA) remain uncertain. To summarize the current status of anti-inflammatory therapy for PTOA, we conducted a systematic review. 9 clinical studies in humans were identified applying anti-inflammatory agents to prevent or treat PTOA. A total of 347 patients aged an average 41 ±â€ˆ14 years were included in this review. 5 studies had comparable designs with randomized allocation. Those studies of course had a statistically significant higher Coleman Methodology Score (65 ±â€ˆ6) than the case-control studies (39 ±â€ˆ13, p = 0.013). The most frequently reported main outcome parameter was pain assessed by different scales (n = 7), the most examined joint the knee (n = 7). The majority of the analyses (n = 6) focused on the intra-articular (IA) application of hyaluronic acid (HA) reporting mainly positive effects. One study stated positive results following IA administration of Interleukin 1 receptor antagonist in -patients presenting rupture of the anterior cruciate ligament. Platelet-rich plasma was also used to relieve symptoms following acute injury, but the study quality was too low to conclude any effects. Although the initial data, especially regarding IA HA injection, are encouraging, study designs differ substantially. Therefore, current data does not allow us to conclude that anti-inflammatory therapy following acute injuries has beneficial effects on short- or long-term outcomes.

[Histological, biochemical and spectroscopic changes of articular cartilage in osteoarthritis: is there a chance for spectroscopic evaluation?]. / Arthrosebedingte histologische, biochemische und spektroskopische Veränderungen am hyalinen Gelenkknorpel: Welchen Stellenwert hat die spektroskopische Evaluation?

BACKGROUND: Non-destructive techniques for the detection and classification of pathological changes of cartilage in the early stages of osteoarthritis are required for arthroscopic and open surgery of joints. Biochemical and histological changes in cartilage with different degrees of destruction were analysed and correlated to changes in the spectroscopic characteristics of cartilage. PATIENTS, MATERIAL AND METHODS: 24 patients (n = 25 knees) with severely destructed knee joints received total knee replacement. The cartilage of the resected joints was classified according to the ICRS system. Defined cartilage specimens were investigated spectroscopically employing NIRS (near-infrared spectroscopy). In the following the cartilage specimens were harvested to determine the content of proteoglycan (GAG) and hydroxyproline (HP) as an essential part of collagen. Histological evaluation of the Mankin score and Otte score was performed using haematoxylin/eosin and safranin-O staining. Spearman's rank correlation coefficient was used to characterise links between the parameters investigated. RESULTS: We found significant correlations between spectroscopic, histological and biochemical characteristics. NIRS corresponded to the content of GAG (ρ = 0.58) and HP (ρ = 0.59), as well as to the Mankin (ρ = 0.55) and Otte (ρ = 0.5) scores. Furthermore, the ICRS classification correlated with histological evaluation (Mankin score ρ = 0.725 and Otte score ρ = 0.736), as to be expected. CONCLUSION: Characteristic cartilage changes in different degrees of osteoarthritis can be detected and evaluated by the spectroscopic method NIRS as a non-destructive technique. However, the quality of this technical evaluation cannot compete with biochemical and histological analysis.

2D-fluoroscopic based navigation for Gamma 3 nail insertion versus conventional procedure- a feasibility study.

BACKGROUND: Intramedullary nailing is a standard surgical procedure for fixation of proximal femoral fractures, but is associated with considerable radiation exposure for controlling the implant placement, due to the percutaneous insertion technique.The aim of this study was the evaluation of potential benefits of 2D-fluoroscopic based navigation focused on the reduction of radiation exposure, a decrease of procedure time, as well as an increase of accuracy for Gamma3 nail insertions. METHODS: Twenty randomized Gamma3 nail insertions were performed in non-fractured synthetic femora according to the manufactures operation guidelines (group I) or with use of a 2D-fluoroscopic based navigation system (group II). Time of different steps of the procedure and the radiation exposure were measured, as well as the accuracy evaluated in postoperative CT scans. RESULTS AND DISCUSSION: All Gamma3 nails were placed without any technical problems. Independent of the used procedure, the overall operating time (group I: 584 ± 99.2 sec; group II: 662 ± 64.9 sec; p=0.06) and accuracy of the final nail-positions were equivalent, but the radiation exposure was significantly reduced (92% reduction in fluoroscopic images and 91% reduction in fluoroscopic time, p< 0.01), using the 2D fluoroscopic based navigation procedure. CONCLUSIONS: 2D-fluoroscopic based navigation for Gamma3 nail insertion facilitates a relevant reduction of radiation exposure with equivalent accuracy of the final implant position and no prolonged operating time. This promising procedure modification is independent of different cephalomedullary implant manufacturers and specific implant designs, but needs to be evaluated in further clinical settings.

[Polytrauma with pelvic fractures and severe thoracic trauma: does the timing of definitive pelvic fracture stabilization affect the clinical course?]. / Polytrauma mit Beckenfraktur und schwerem Thoraxtrauma: Hat der Zeitpunkt der definitiven Beckenfrakturstabilisierung Einfluss auf den klinischen Verlauf?

BACKGROUND: The aim of this study was to investigate the influence of the surgical timing in patients with pelvic fractures and severe chest trauma on the clinical course, especially on postoperative lung function. METHODS: A total of 47 patients were included in a prospective dual observational study. The study investigated the clinical course depending on the time of operation based on the functional lung parameters, SAPS II, SOFA and total hospital stay. RESULTS: The average ISS was 32±6, PTS was 34±11 and TTSS was 9±3 points. The pelvic fractures were stabilized definitively after an average of 7±2 days. The early stabilization correlated significantly with a lower TTSS and SAPS II on admission (p<0.05), shorter time of ventilation (p<0.05) and stay in the intensive care unit (p<0.01) as well as the decreased need for packed red blood cells (p<0.01). CONCLUSIONS: In this study patients with pelvic fractures and thoracic trauma benefited positively from an earlier definitive pelvic fracture stabilization with respect to a shorter time of ventilation and stay in the intensive care unit due to a lower need for red cell concentrates.

[Locking attachment plate - first experience]. / Locking Attachment Plate - Erste Erfahrungen.

BACKGROUND: In this paper we present our first experience in the application of a new, fixed-angle plate fixation: the locking attachment plate (LAP, Synthes, Oberdorf, Switzerland). We examined whether the LAP is a useful addition to the existing technical palette for periprosthetic fractures. The LAP is used for periprosthetic fractures with stable prostheses or intramedullary implants. The plate can be installed, e.g., on a 4.5 mm locking compression plate (LCP). Locking screws or cortical screws can be placed through its 4 diagonal fixed-angle arms, bicortical around the prosthesis stem into the bone. The LAP is designed to prevent lateral screw pull-out, to stabilise the prosthesis stem and thus to allow early postoperative mobilisation of patients. PATIENTS AND METHODS: We implanted the LAP by operative fracture-treatment in the ORIF technique in 17 patients with periprosthetic fractures of the femur, tibia and humerus. The follow-up was at least 13 months. RESULTS: There were two losses to follow-up: the patients died a few weeks postoperatively. There was a total of two of 17 cases with infection events (11.8 %). We could examine 15 patients for follow-up. Eleven of these 15 patients regained their original range of motion (ROM) and nine of 15 patients their pretraumatic mobility. In all cases with periprosthetic humeral fractures we detected muscular deficits. In five out of 15 cases (33.3 %) no radiological fracture healing could be observed. Nevertheless in 14 of 15 cases the implant was stable without signs of implant or prosthetic loosening. There was no case of material failure. CONCLUSION: Periprosthetic fractures are an increasingly common complication in old, often multi-morbid patients. A contemporary therapeutic intervention and early postoperative mobilisation contribute substantially to the success of treatment. The first results in the use of the LAP as a new implant option for periprosthetic fractures of the femur, tibia and humerus are promising. Further studies are necessary to show whether our overall good results are reproducible in larger groups of patients and whether the LAP can be given a firm position in the technical repertoire for treatment of periprosthetic fractures.

Navigation in femoral-shaft fractures--from lab tests to clinical routine.

INTRODUCTION: This study evaluates the use of a navigation system (BrainLAB, Feldkirchen, Germany) to intra-operatively check for correct length, axis and rotation in intramedullary nailing of femoral-shaft fractures in an experimental setting and in clinical routine. MATERIALS AND METHODS: We tested the navigation system in two experimental settings before introducing it into clinical routine. In the first experiment, 10 osteotomised model femora were fixed with intramedullary nails by using a navigation system. The goal was a locking fixation in predefined values for length and rotation. In the second experiment, eight examiners assessed values for rotation and length of one femur 10 times to examine the accuracy and reproducibility of that determination. Following this, we navigated 40 femoral nailing procedures in our department. Preoperatively, we assessed values of femur geometry on the contralateral side in a computed tomography (CT) scan and reproduced these values intra-operatively on the fractured side, guided by the navigation system. During the intervention, we recorded the length of the procedure steps and the fluoroscopy time. We verified the intra-operative values achieved with the navigation system in a postoperative CT scan and documented differences in rotation and length. After the assessment, we analysed the data for different findings on femur geometry, fluoroscopy time and procedure duration. RESULTS: The experimental evaluation showed a range of ±5° for anteversion differences and ±2.3 mm for length differences. We estimated this accuracy as sufficient to use the system in clinical routine. The navigation system was used for 40 fracture fixations. All our criteria for restoring femoral geometry could be achieved by navigation guidance in these procedures. Setting up the system took on average 33±11.5 min. An additional fluoroscopy time of 36±22 s was needed to acquire the reference X-rays and to verify pin placement. The differences between anteversion values assessed in intra-operative planning steps on the navigation system and values assessed with a postoperative CT were on average 5.4±3.5°, whilst femur length differed on average by 4±4 mm. DISCUSSION: Many authors judge intra-operative control of anteversion in femoral-shaft fracture fixation as problematic. Neither our experimental navigation assessment nor our clinical navigated evaluation showed relevant anteversion differences to a postoperative CT assessment of femur geometry. After initial training, guidance by a navigation system achieves consistent results in a clinical situation. CONCLUSIONS: The use of a navigation system to align axis, length and rotation led to a secure way of avoiding any relevant malalignment in complex femur-shaft fractures whilst exposing patients to an acceptable amount of additional procedure sequences. Malalignment can be avoided by using a navigation system in the operative treatment of femoral-shaft fractures and may be integrated into clinical routine in specialised centres.

[Delayed diagnosis of fractures of the capitulum of the humerus. Successful internal fixation 6 weeks after the accident]. / Verzögert diagnostizierte capitulum-humeri-frakturen beidseits. Erfolgreiche osteosynthese 6 wochen nach unfall.

Fractures of the capitulum of the humerus are rare and difficult to recognize. At present conservative therapy is only indicated in a few cases with no dislocation of the fracture. Otherwise an anatomical reduction and internal fixation should be done as early as possible. This article reports the case of a 51-year-old female patient with bilateral fractures of the capitulum of the humerus which were diagnosed 6 weeks after trauma. In spite of the extra risk of fragment necrosis, a reduction and internal fixation were performed. After rehabilitation, the patient was free of complaints except for a minimal limited range of motion.

[Sustentaculum tali screw placement for calcaneus fractures--different navigation procedures compared to the conventional technique]. / Sustentaculum-tali-Schraubenplatzierung bei der Versorgung von Kalkaneusfrakturen--verschiedene Navigationsverfahren im Vergleich zur konventionellen Technik.

AIM: Precise placement of the sustentaculum tali screw is essential for fixation of calcaneus fractures to achieve the best fixation strength. In the clinical practice, this procedure is demanding due to the complex anatomic configuration of the calcaneus and the limited visualisation in the intraoperative fluoroscopic images. The aim of this study was an evaluation of the accuracy for the sustentaculum tali screw placement by using different navigation procedures compared to the standard procedure. The different navigation specific workflows were evaluated and the feasibility of each procedure proven in clinical applications. METHOD: Eight sustentaculum screws per group were placed in an artifical Synbone model. Different navigation procedures were evaluated: 2D-fluoroscopy (group I), 3D-fluoroscopy (group II), fluoro-free (group III) and compared to the conventional screw placement without navigation (group IV). For each screw the time of fluoroscopy and the duration of the procedure were measured. The accuracy was evaluated postoperatively by computed tomography using axial slices and coronary as well as sagittal reformations. Furthermore, the workflow of each navigation procedure was analysed and proven in clinical applications. RESULTS: In the experimental setup, no radiation exposure was mandatory for the conventional and fluoro-free procedures, whereas mean fluoroscopy times of 17 +/- 1.03 und 66.8 +/- 0.9 were measured for 2D- and 3D-navigation procedures. In line with this, the overall mean procedure times for the screw placement were 1.26 +/- 0.05 (group IV), 3.49 +/- 0.26 (group III), 13.32 +/- 0.49 (group I) und 19.04 +/- 1.41 minutes (group II). No significant differences were observed for the accuracy of screw placement. In the clinical practice a better orientation was achieved by use of a navigation system. The fluoro-free procedure can be easily integrated into the common operation workflow, whereas the workflow of both image-based navigation procedures is technically demanding. CONCLUSION: Navigation procedures seem to be helpful for the precise placement of sustentaculum tali screws in cases of operative calcaneus fracture fixation. The kind of application to be used depends on the infrastructure of the department and the navigation-experience of the operating room team. Whereas the fluoro-free procedure is intuitive in use, the 2D-navigation does not justify the extra efforts. The 3D-procedure is the recommended application for surgeons familiar with navigation, providing the best orientation due to the slice image visualisation in all three dimensions.

[Navigation-assisted nailing of femoral shaft fractures--experimental and clinical results]. / Navigationsgestützte Marknagelung von Femurschaftfrakturen - experimentelle und klinische Ergebnisse.

AIM: The aim of the study was to evaluate the application of a navigation system (Brainlab) to control length and torsion intraoperatively while nailing a femoral shaft fracture. METHOD: At first the system was tested with 10 fractured synthetic bones. The postoperatively reached length and torsion were measured and the difference to the envisioned values statistically evaluated. Clinically we used the navigation system for patients with complex femoral shaft fractures. We always performed a preoperative computed tomography of the opposite leg to analyse the axis and fixed the fractured leg on these parameters using the navigation system. We noticed as improvement opportunities, the duration of the operative steps and the radiation exposure. The operative result was radiologically controlled and the torsion and length differences to the intraoperative measurement evaluated. Furthermore, we analysed the duration of the operation steps including the additional radiation exposure. RESULTS: There were no technical problems during operations on the synthetic bones. The accuracy was with +/- 5 degrees or +/- 2 mm good enough to use the already approved system clinically. The navigation system was used for 17 operations. All navigation-assisted operations were completed successfully. It took an average time of 32 min to install the navigation system and required an additional X-ray time of 44 sec. The average postoperative rotational deviation was 5.5 degrees . The average difference in length was 2 mm. CONCLUSION: The application of a navigation system for repositioning of femoral shaft axes and controlling the length and torsion while nailing complex femoral shaft fractures is associated with some additional work. Nevertheless, in our study a relevant rotational deviation can be avoided by using the navigation system. To prove the advantage of the navigation system over the conventional technique, clinical studies with larger number of cases are necessary.

[2D-fluoroscopic navigated screw osteosynthesis of acetabular fractures: A preliminary report]. / 2D-fluoroskopisch navigierte perkutane Schraubenosteosynthese von Azetabulumfrakturen: Erste Ergebnisse einer neuen Methode.

INTRODUCTION: The current gold standard for operatively treated acetabular fractures is open reduction and internal fixation. In this study we report the early results of percutaneous screw osteosynthesis of acetabular fractures in 14 cases, using a computer navigation system to reduce screw misplacement, approach associated risks and radiation exposure. RESULTS: All 36 acetabular screws were placed correctly without any perioperative complication. The mean operation time per screw was 54 min, the mean fluoroscopic time per screw was 87 s. In the follow-up examinations (current rate: 71 %, mean follow-up: 13.1 +/- 1.8 months) no fixation failure or development of post-traumatic osteoarthritis was seen. One wound infection occured. CONCLUSION: Our first experience with this novel approach is promising and serious advances of fluoroscopic navigated percutaneous screw osteosynthesis of well selected acetabular fractures can be expected.

[Treatment of bilateral distal tibial nonunions. Use of an intramedullary compression nail and a modified locking compression plate osteosynthesis]. / Differenzierte Behandlung beidseitiger distaler Tibiapseudarthrosen. Modifizierte winkelstabile Plattenosteosynthese und Kompressionsmarknagel.

Operative treatment of distal tibial fractures remains a challenge for the surgeon even today. The soft tissues demand atraumatic operative techniques, although an anatomical reduction of the articular fracture component is mandatory. The nonunion rate increases with disturbed local blood supply, widened fracture gap, unstable fixation. If a nonunion occurs, an individual treatment concept is required, so that even difficult situations can be successfully managed, as described in our case with bilateral tibial nonunions.

[Fractures of the distal radius. Minimally invasive pin fixation: indications and results]. / Der distale Speichenbruch. Minimalinvasive Kirschnerdrahtosteosynthese. Indikation und Ergebnisse.

Therapy of distal radius fractures in the elderly is increasingly subject to higher demands on functional results, especially in terms of patient comfort, load-bearing, tissue atrophy, and osteoporosis. From 1 January 1998 until 30 June 1999, 215 patients with distal radius fractures were treated at our hospital. One hundred eighteen of them had follow-up examinations after an average of 33 months. Using objective criteria (X-ray and functional), results were very good in 68.9% of the cases and good in 28.6%. Under subjective criteria, too, most of the patients had very little or no complaints (68%). These results underline the need and usefulness of differentiating operative therapies according to the fracture type in the AO classification system.

[Differential therapy in radial head fractures]. / Differenziertes Behandlungskonzept der Radiusköpfchenfraktur.

The therapeutic regimen of radial head fractures, especially of displaced and comminuted types is controversial. The radial head resection has been critically reviewed over the past years. From 1984-1993 and 1996-1999, 105 radial head fractures were treated in our hospital. 74 were subject to clinical and radiological follow-up. Fracture-types were classified according to Mason. Undisplaced fractures were treated conservatively, displaced 2-fragment-fractures by an open reduction and screw fixation, and multifragment-fractures by a radial head resection. The results were studied on a functional and radiological basis using the "Functional Rating Index" of Broberg and Morrey and the radiological Score of Albrecht and Ganz. After conservative therapy over 80 % achieved excellent and good as well as 12.5 % satisfactory and 6.3 % unsatisfactory results. After reduction and internal fixation again 80 % had excellent and good results. After radial head resection excellent and good results were achieved in 54.6 % of the cases, satisfactory results in 24.2 % and in 21.2 % unsatisfactory results, however prognosis-influencing concomitant injuries were often present in the latter group. Using the right indication and technique, the radial head resection still is a recommendable therapeutic procedure with an altogether good prognosis. This especially applies to isolated radial head fractures where excellent and good results can be achieved in approximately 70 %.

[Living conditions and mortality in the elderly after surgical management of para-articular hip fractures]. / Lebensbedingungen und Letalität alter Menschen nach operativer Versorgung hüftnaher Oberschenkelbrüche.

While hemiendoprothesis has been established in the treatment of hip fractures of aged people because of less operative trauma, better effectiveness and satisfying functionality, surgical management of trochanteric fractures is still in discussion. In our study, we found no severe difference of living conditions or mortality after operating elderly patients with proximal femoral fractures comparing Hemiprotheses versus Endernails versus Dynamic Hip Screws.