[Femoral shaft fractures]. / Femurschaftfraktur.

Femoral shaft fractures after completion of growth predominantly affect young people with healthy bones. The causes are mostly high-velocity traffic accidents, crushing or running over mechanisms and falls from a great height. Gunshot wounds are relatively rare in Germany but have a certain importance internationally and in military medicine. Accompanying injuries in local or other regions are frequent. The predominant fracture types are transverse, wedge, segment and comminuted fractures. Spiral fractures are a sign of indirect force and are therefore frequently found in older patients with osteoporosis. Atypical fractures under or following bisphosphonate treatment are a new entity, which are typically subtrochanteric and begin on the lateral side of the bone. The characteristics of pathological fractures, femoral shaft fractures in childhood and adolescence as well as periprosthetic fractures are not dealt with in this article.

[Atypical subtrochanteric femur fracture under alendronate therapy in spite of an intramedullar implant]. / Atypische subtrochantäre Femurfraktur unter Alendronsäuretherapie trotz intramedullärem Implantat.

There are a number of case reports about women undergoing long-term bisphosphonate therapy who have suffered an atypical subtrochanteric or femoral shaft fracture due to an inadequate trauma.The present case reports on a patient who underwent a subtrochanteric femur fracture with the inserted AO femur interlocking nail.

[Surgical treatment of skeletal metastases]. / Chirurgische Therapie der Skelettmetastasen.

The prevalence of cancerous diseases in Germany is rising. The skeletal system represents the third most common localization for metastases. Nearly two thirds of metastases are found in the region of the spine. Due to longer survival times of tumor patients in the metastasis stage, an increase in the number of patients with bone metastases is to be expected. The treatment of patients with osseus metastases is nowadays an integral component of orthopedic trauma surgery practices. This article presents the principles of the diagnostics, provides aids for estimation of the prognosis and danger of fractures and discusses the various surgical treatment procedures for skeletal metastases with the accompanying advantages and disadvantages.

[Benign bone tumors. General principles]. / Gutartige Knochentumoren. Allgemeine Prinzipien.

BACKGROUND: Benign bone tumors and tumor-like lesions are much more frequent than malignant bone tumors among the total number of tumors of the skeleton. OBJECTIVE: This article gives a presentation of the characteristics and treatment modalities of benign bone tumors. MATERIAL AND METHODS: In this article in-house treatment principles are compared with those in the currently available literature. RESULTS: Benign bone tumors are frequently found incidentally; however, the term benign does not always signify that a purely observational role is needed. Benign bone tumors differ in their biological behavior and can be latent, active or aggressive which determines the treatment approach. Some benign bone tumors are just as aggressive locally as malignant tumors. The most important diagnostic feature is still conventional radiography and a thorough systematic analysis is necessary. Therapy options range from ignore, wait and see up to wide resection. In contrast to malignant tumors the radicalism of resection can be weighed against the accompanying local control and loss of function. CONCLUSION: The treatment of benign bone tumors depends on the histological type and the biological activity. Most benign bone tumors are diagnosed incidentally and do not necessitate any treatment.

Femoral shaft fractures in adults: treatment options and controversies.

Antegrade reamed femoral nailing via the piriformis entry point is the technique of choice in treating femoral shaft fractures, with retrograde nailing as an alternative. The supine position is favored to reduce complications, especially rotational malalignment. With navigation and robotic assistance fracture reduction can be supported and the rate of rotational, axis and length malalignement can potentially further reduced. Careful reaming is the procedure of choice to optimize bony healing and reduce systemic and local complications. In multiply injured patients reamed nailing can be safely integrated in the DCO- or ETC-concept and can be performed in the majority of patients, even when additional severe chest and head injuries are present. Initial resuscitation should focus on general stabilization before definitive femur fixation. Plate osteosynthesis of the femur can be an option in selected patients.

[Significance of sonographically guided percutaneous needle biopsy in the diagnostics of soft tissue tumors]. / Stellenwert der sonographisch kontrollierten perkutanen Stanzbiopsie in der Diagnostik von Weichgewebstumoren.

BACKGROUND: The role of percutaneous needle biopsy in the diagnostics of soft tissue tumors is controversially discussed. The specificity of this method has been examined in this study based on the collective of patients treated in our university hospital. Secondly, the influence of the specialization of the treating surgeon has been evaluated. PATIENTS AND METHODS: This study included 96 patients who underwent percutaneous needle biopsy and, if necessary, surgical resection. The specificity, logistic requirements and possible complications of percutaneous biopsy were evaluated. Special attention was paid to the influence of specialization of the treating surgical team on the specificity of the method. RESULTS: The results of the biopsy were able to define the entity of the lesion correctly in 69.7 %, the dignity in 75.0 % and the grading in 72.0 % of the cases. In the group treated by a specialized team, the specificity of the method was 84.6 % concerning the entity of the lesion, 84.6 % concerning the dignity and 80 % concerning the grading. With regard to the entity the specificity was significantly increased (p < 0.05). CONCLUSION: The findings show that percutaneous needle biopsy represents a logistically simple and efficient diagnostic method for soft tissue tumors which is rarely associated with complications. Subsequent treatment should be performed in a specialized centre.

A clinical, radiological and computational analysis of the thrust plate prosthesis in young patients.

BACKGROUND AND PURPOSE: A thrust plate prosthesis can be used as an alternative to a conventional stem prosthesis, preserving the diaphyseal bone stock. Recent findings however predict a higher rate of aseptic loosening than with intramedullary devices. The purpose of our investigation was to compare the clinical outcome and radiological findings with a finite element analysis of bone remodeling. The hypothesis was that aseptic loosening after thrust plate prosthesis of the hip is inherent to the design. METHODS: From 1997 to 2001, 58 thrust plates were implanted in 52 patients. Average age at the time of surgery was 40.9 years. Ninety four percent returned for follow up at an average of 26 months. A finite element model of the thrust plate within the femur was developed and stress shielding as well as bone remodeling were analyzed. RESULTS: A total of 4 patients required revision surgery (6.9%). Data from the finite element analysis revealed an inherent failure mechanism to the implant, facilitating stress shielding and loosening. INTERPRETATION: Lacking the ideal total hip prosthesis in young patients, the thrust plate can still be regarded as a feasible implant. However, surgeons and patients should be aware of possible mechanical problems regarding the design of the thrust plate. There is evidence that thrust plate prostheses are prone to early aseptic loosening. Clinical and radiological observations are in agreement with the results from the numerical simulations. Stress concentrations computed at the leash are interpreted as an explanation for leash pain. The authors regard computational methods as an aid to improve existing prosthesis design and future developments.

[Vertebral fractures due to osteoporosis. Kyphoplasty and vertebroplasty vs conservative treatment]. / Osteoporosebedingte Wirbelkörperfrakturen. Kyphoplastie und Vertebroplastie vs. konservative Therapie.

Vertebral compression fractures are among the most common forms of manifestations of osteoporosis. Conservative treatment comprises adequate analgesia, osteoporosis medication and individualized physiotherapy or braces. Nevertheless, vertebral compression fractures frequently lead to persisting pain and decrease daily activity and quality of life. In these cases, kyphoplasty and vertebroplasty can be efficient treatment options. Vertebroplasty is a minimally invasive procedure, in which bone cement is filled into the vertebral body under fluoroscopic control. In most cases, this internal stabilization leads to a rapid reduction in pain. Kyphoplasty additionally aims to correct the kyphotic deformation of the broken vertebra via introducing and inflating a balloon catheter. There is broad clinical experience with both procedures. For kyphoplasty, randomized controlled trials showed significant improvements in pain and quality of life in patients undergoing kyphoplasty. However, cement leakages lead to rare but severe complications such as pulmonary embolism and nerve palsies.

Improved intra-operative reduction control using a three-dimensional mobile image intensifier - a proximal tibia cadaver study.

This study aimed to analyse whether the precision of a three-dimensional mobile image intensifier (ISO-C 3D) differs from conventional two-dimensional fluoroscopy and high resolution CT scan in a fracture model of the proximal tibia. A depression fracture of the medial plateau (AO/OTA 41-B2.3) was created in 12 formalin-fixed, human cadaver knees. The cartilage of the depression could be positioned above (+1mm, +2mm), below (-1mm, -2mm), or in line with the joint surface. Fluoroscopy, computed tomography (CT) scans, and ISO-C 3D scans (four different protocols: 100 images, 66 images, 50 images, and 33 images) were done for each fracture level. Three independent observers assessed each imaging set. The difference between the estimated reduction and the real reduction was used for statistical analysis. Our hypothesis was that no differences in the precision exist between the imaging techniques (p<0.05). The conventional image intensifier group (0.7 mm+/-0.67) showed significantly higher deviations than the CT group (0.3 mm+/-0.43; p<0.001) and significantly higher deviations than all ISO-C 3D groups (0.4-0.5 mm; p<0.001). Of the ISO-C 3D groups, only the scan protocol with the lowest number of images (0.5 mm+/-0.51) showed significantly lower precision than the CT group (p<0.001). It was concluded that the three-dimensional mobile image intensifier showed higher precision in reduction assessment in a fracture model of the tibial plateau compared to fluoroscopy. High resolution CT scans should remain the standard for post-operative assessment of reduction outside the operating theatre.

[Traumatology of the spine]. / Traumatologie der Wirbelsäule.

Spinal trauma poses considerable threats to survival and quality of life. Especially cervical spine injuries are often associated with neurologic deficits. A thorough diagnostic pathway, often including computed tomography with sagittal reconstruction, is mandatory to evaluate the extent and consequences of spinal trauma. Every treatment must aim to restore stability and prevent secondary neurologic deterioration. Compression fractures usually can be treated successfully with conservative treatment, while burst fractures usually, and flexion/distraction injuries, and fracture-dislocation generally require internal stabilization. Injuries of the upper cervical spine can be treated conservatively or operatively, depending on the degree of instability. In the lower cervical spine, most injuries require internal fixation.

Do K-wires made from shape memory alloys increase pull-out forces? A preliminary experimental cadaver study in bovine bone.

After osteosynthesis of the proximal humerus by Kirschner wires (K-wire), loosening and secondary loss can occur. This study tested primary fixation of wires made from a shape memory alloy (SMA) Nitinol (NiTi), compared to conventional steel K-wires by pull-out tests. Blocks of cancellous bone were tested with three wire types: NiTi-K-wire with split apex geometry and conventional steel K-wires with and without threads. We found that NiTi-wires can be pulled out of bone more easily than steel wires (P=0.05), even though the former had rougher surfaces. The application of NiTi-wires through bone produced no better stability in comparison to normal steel K-wires, because of triggering the memory effect. Further studies are required to determine if NiTi wires of another appropriate design, surface and localization are superior to conventional wires in the context of this application.

Computer-assisted analysis of lower limb geometry: higher intraobserver reliability compared to conventional method.

Exact radiographic evaluation of lower limb alignment, joint orientation and leg length is crucial for preoperative planning and successful treatment of deformities, fractures and osteoarthritis. Improvement of the accuracy of radiographic measurements is highly desirable. To determine the intraobserver reliability of conventional analysis of lower extremity geometry, 59 long leg radiographs were randomly analyzed 5 times by a single surgeon. The measurements revealed a standard deviation between 0.36 degrees and 1.17 degrees for the angles mLPFA, mLDFA, MPTA, LDTA, JLCA and AMA (nomenclature according to Paley), and 0.94 mm and 0.90 mm for the MAD and leg length, respectively. Computer-assisted analysis with a special software significantly reduced the standard deviation of the mLDFA, MPTA, LDTA, JLCA (each p < 0.001), AMA (p = 0.032) and MAD (p = 0.023) by 0.05-0.36 degrees and 0.14 mm, respectively. Measuring time was reduced by 44% to 6:34 +/- 0:45 min (p < 0.001). Digital calibration by the software revealed an average magnification of conventional long leg radiographs of 4.6 +/- 1.8% (range: 2.7-11.9%). Computer-assisted analysis increases the intraobserver reliability and reduces the time needed for the analysis. Another major benefit is the ease of storage and transfer of digitized images. Due to the varying magnification factors on long leg radiographs, the use of magnification markers for calibration is recommended.

Robot-assisted fracture reduction: a preliminary study in the femur shaft.

Reduction in femoral shaft fractures can be difficult to achieve with minimally invasive techniques. Malalignment and high intra-operative radiation exposure can result. The hypothesis was that robot-assisted fracture reduction could improve the quality of reduction while reducing the amount of radiation exposure. A robot system was developed that allows fracture manipulation with a joystick as input device. The system provides the surgeon with haptic and metric feedback. Fifteen synthetic femurs were broken and reduced by simulated open (group A) and closed techniques (group B). These techniques were compared with the robot-assisted reduction with (group C) and without (group D) haptic and metric information. An image intensifier was simulated with two orthogonal cameras. All reduction techniques showed minor malalignment. In group C, the alignment was: procurvatum/recurvatum 0.6 degrees (0-2.0 degrees); varus/valgus 0.8 degrees (0-3.0 degrees); and axial rotation 0.8 degrees (0-3.1 degrees). A significant difference was seen between the groups (two-way ANOVA, p < 0.001). Axial rotation was significantly lower in group C than in group B (1.9 degrees; p < 0.001). The residual varus and valgus deviation was higher in group C compared with group A (0.4 degrees, p = 0.03). The median number of simulated radiographs was significantly less in group C (35) compared with group D (72; p < 0.001) and group B (49; p = 0.01). Robot-assisted fracture reduction of the femur provides high precision in alignment while reducing the amount of intraoperative imaging. Further research in this field is worthwhile.

[Indication for removal of tibial nails]. / Indikation zur Entfernung von Tibiamarknägeln.

BACKGROUND: Tibial nail removal has been suggested as a routine procedure for both symptomatic and asymptomatic patients. The aim of this study was to define guidelines for the removal of tibial nails. PATIENTS AND METHODS: A retrospective study on the isolated removal of 69 tibial nails after fracture consolidation was done. A review of the patient charts and radiographs was performed. Forty-four patients (64%) were available for the follow-up interview. RESULTS: Preoperatively, 26 patients (59%) had local complaints. Of these 26 patients, 73% reported an improvement, and 8% reported an aggravation of their local complaints. Of the 18 patients who were asymptomatic before surgery, 17% reported long-term complaints at follow-up. CONCLUSION: We conclude that routine removal of tibial nails should be discussed critically in asymptomatic patients.

[Prospective proprioceptive and coordinative training for injury reduction in elite female soccer]. / Prospektives Propriozeptions- und Koordinationstraining zur Verletzungsreduktion im professionellen Frauenfussballsport.

PURPOSE: Does a prospective proprioceptive-coordinative additional training intervention in elite female soccer changes frequency and pattern of injuries? MATERIALS AND METHODS: 24 female soccer players of the German first division team of FC Bayern München were thoroughly supervised during the season 2003/04 regarding injuries resulting in an absence from at least one scheduled training session or game. During the winter break an additional proprioceptive-coordinative training program was initiated, which was performed on a regular basis during the second half of the season. Furthermore, we evaluated jump&reach, throwing power, coordinative skills, and flexibility. RESULTS: All evaluated fitness results increased significantly during the season after the training intervention, such as jump&reach 44 +/- 4 cm vs. 38 +/- 10 cm (p < 0.05), coordinative power left and right leg, respectively (71 +/- 44 s vs. 45 +/- 37 s, 80 +/- 41 s vs. 50 +/- 32 s, both p < 0.05), flexibility left and right hip (89 +/- 8 degrees vs. 78 +/- 13 degrees and 88 +/- 9 degrees vs. 79 +/- 10 degrees, p < 0.05). Comparing the 1st to the 2nd half of the season, 25 vs. 26 injuries after foulplay and 69 vs. 52 without contact occur (p < 0.05). Muscle injuries resulting in game or training absence were significantly reduced by 400% (12 vs. 3, p < 0.05). In the 1st half of the season, 2 anterior cruciate ruptures (ACL) occur vs. none in the 2nd half after the training intervention. CONCLUSION: An additional proprioceptive-coordinative training intervention increases coordinative abilities, jump power, throwing power, and flexibility during a half season. After initiation of the proprioceptive-coordinative training the incidence of muscle injuries resulting in an absence of at least one game or practice session was reduced significantly by 400 %. Regarding the reduced incidence of ACL injuries after proprioceptive-coordinative training in female elite soccer players, further studies have to be performed to elucidate the value of this training intervention.

Less invasive stabilization of complex tibial plateau fractures: a biomechanical evaluation of a unilateral locked screw plate and double plating.

OBJECTIVE: To compare the vertical subsidence in a bicondylar tibial plateau fracture model stabilized either by a unilateral locked screw plate (LSP) or by double plating. DESIGN: Biomechanical cadaver study. INTERVENTION: A 41-C1 fracture model was created in eight pairs of fresh-frozen human cadaver tibiae. Stabilization was performed either by open reduction and internal fixation (ORIF) using a lateral L-buttress plate and a medial four-hole, one-third tubular antiglide-plate or by a lateral LSP. Four load levels (400N, 800N, 1200N, 1600N), each with five cycles, were consecutively applied to the medial plateau. MAIN OUTCOME MEASUREMENTS: The vertical plastic deformation at the end of each cycle was the main parameter of interest. Statistical analysis was performed with the two-way ANOVA test for repeated measurements. Each individual loading level was analyzed separately using Student t test. RESULTS: In one pair, both fixation techniques failed at the first loading cycle of 1200N. One ORIF fixation failed at the first loading cycle of 1600N. The average plastic vertical subsidence was 0.40 mm (LSP) and 0.25 mm (ORIF) at 400N (P = 0.291), 0.83 mm (LSP) and 0.81 mm (ORIF) at 800N (P = 8.82), 1.06 mm (LSP) and 0.96 mm (ORIF) at 1200N (P = 0.98), and 1.54 mm (LSP) and 1.14 mm (ORIF) at 1600N (P = 0.53). Vertical subsidence depended on the applied load (P = 0.002), but not on the method of fixation (P = 0.236). CONCLUSION: Both fixation techniques have a high resistance to vertical subsidence even with loads exceeding the average body weight. No statistically significant difference was seen between the two methods of fixation.

Acute transient bilateral trigger fingers.

A 30-year-old man presented with bilateral, simultaneous, transient triggering of the middle digits which developed acutely after prolonged and sustained use of a garden rotavator. He was asymptomatic in the period before presentation and has remained so 7 years since.

[Diagnostics and treatment of primary bone tumors]. / Diagnostik und Therapie primärer Knochentumoren.

Primary bone tumors can be either benign or malignant. Metastization is a characteristic feature of malignant bone tumors. Malignant tumors are characterized by a local aggressive and destructive behavior. The behavior of a tumor is dependent on its entity, the differentiation grade and localization and these factors are of decisive importance for the correct therapy. Even benign tumors can behave very aggressively. Different stages are defined. Patient history and conventional radiographs are the most powerful primary diagnostic tools. Many tumors show typical characteristics and if a malignant lesion is suspected a biopsy should be carried out. Several quality standards have to be respected when making the biopsy. The approach to malignant tumors is always interdisciplinary. Several biological as well as alloplastic reconstruction techniques exist. The treatment of primary malignant bone tumors requires a lot of experience and should only be done in specialized centers.

Development of a fixation device for robot assisted fracture reduction of femoral shaft fractures: a biomechanical study.

Robot assisted fracture reduction of femoral shaft fractures provides precise alignment while reducing the amount of intraoperative imaging. The connection between the robot and the fracture fragment should allow conventional intramedullary nailing, be minimally invasive and provide interim fracture stability. In our study we tested three different reduction tools: a conventional External Fixator, a Reposition-Plate and a Three-Point-Device with two variations (a 40 degrees and a 90 degrees version). We measured relative movements between the tools and the bone fragments in all translation and rotation planes. The Three-Point-Device 90 degrees showed the smallest average relative displacement and was the only device able to withstand the maximum applied load of 70 Nm without failure of any bone fragment. The Three-Point-Device 90 degrees complies with all the stipulated requirements and is a suitable interface for robot assisted fracture reduction of femoral shaft fractures.