[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.

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.

[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.

[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.

Prophylactic gastrostomy tubes for patients receiving radical radiotherapy for head and neck cancers: a retrospective review.

Patients undergoing radical radiotherapy for head and neck cancers often experience significant complications. We sought to evaluate the impact of prophylactic gastrostomy tubes (PGTs) among these patients on four easily evaluable adverse outcomes, namely, absolute weight loss, percentage weight loss, admissions for nutritional reasons and treatment interruptions. A retrospective review was carried out on patients undergoing radical radiotherapy for primary head and neck cancers from September 1999 to October 2005 at the Wellington Blood and Cancer Centre (n = 71). PGTs were placed in 7 (10%) patients. Patients with PGTs were compared with the patients without PGTs (the control group) by univariate and multivariate analyses. By univariate analysis, there was no significant difference in absolute or percentage weight loss between those with PGTs and the control group. By multivariate analysis, those with PGTs lost 5.2% (P = 0.016) less weight than the control group. There were no significant differences between the two groups with regard to admissions for nutritional reasons or treatment interruptions. The use of PGTs can reduce weight loss in patients undergoing radical radiotherapy for head and neck cancers, and its use should be further evaluated in future studies.

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.

[Management of bicondylar fractures of the tibial plateau with unilateral fixed-angle plate fixation]. / Versorgung von bikondylären Tibiakopf-Frakturen mit einem unilateral platzierten winkelstabilen Plattensystem.

BACKGROUND: This study was initiated to evaluate early results of a locked screw plate for unilateral fixation of bicondylar fractures of the tibial plateau. Emphasis was laid on malreduction, secondary loss of reduction, union rate, and infection. MATERIAL AND METHODS: A case series of patients with AO/ASIF 41-C type fractures treated with the less invasive stabilization system for the proximal lateral tibia (LISS PLT) were prospectively followed up until 11-13 months after surgery. Malreduction and malalignment were defined as an intra-articular step-off of 2 mm or more or as a malalignment in the frontal or sagittal plane of more than 5 degrees. RESULTS: Sixty-eight patients with 69 fractures were involved. Fourteen fractures were open. Primary bone grafting was performed in 13 patients. Significant malreduction was seen in 16 patients. Sixty-two (91%) patients returned for follow-up. All but one fracture healed eventually. The number of infections was low (4 superficial, 1 deep). Nine patients had a significant loss of reduction. Of 54 patients outcome scores were good to excellent in 47 patients on the Lysholm score (average 87.2) and in 44 patients on the Rasmussen score (average 26.7). CONCLUSION: We concluded that unilateral locked screw plating is a good alternative in the treatment of problematic fractures of the tibial plateau that are associated with soft tissue damage and metaphyseal comminution. The reduction technique for exact alignment is demanding.

[Cost-benefit analysis of intraoperative 3D imaging]. / Kosten- und Nutzenanalyse der intraoperativen 3D-Bildgebung.

BACKGROUND: With intraoperative 3D imaging, inevitable corrections may be done already during the operation, and a second procedure can be avoided. The purpose of this study was to perform a cost-benefit analysis during the first year of intraoperative 3D application in order to provide a cost transparency for the surgeon within the current DRG system. METHODS: On the basis of internal data and the literature, the annual operating costs of the ISO-C(3D) were calculated at 27,940 euros (purchase price, depreciation, maintenance, repair), the costs of an average revision as a secondary operation at 2,385 euros (costs avoided with the ISO-C(3D), Siremobil, Siemens, Erlangen, Germany), and the dynamic costs of an intraoperative 3D scan were averaged to 131.08 euros (draping, additional time, personnel). RESULTS: In the year 2003 intraoperative 3D scanning was done in 126 patients, and intraoperative revision was performed in 24 (19%) due to the additional intraoperative 3D information provided by the Siremobil. In 11 (8.7%) patients the implant position was corrected and in 13 (10.3%) patients the reduction was improved. Taking only fixed costs into consideration, 29,311.52 euros could be saved, and when fixed and dynamic costs are taken into account 12,795.44 euros could be saved. Since the parameters for each hospital are different, the following formula for an individual computation is suitable. For the calculation of the cost the following mathematical relationship results: (annual fixed costs) + (costs per scan x number of cases) - (revision costs x revision rate [p]) x number of cases [N]) = 0. DISCUSSION: Although the costs of an ISO-C(3D) are considerably high, an economic benefit can also accrue with frequent application and high rates of avoided revision. However, if the rate of avoided revision adds up to only 5%, a substantial deficit may result.

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.

Microcirculation of the ankle after Cryo/Cuff application in healthy volunteers.

The aim of the study was to assess the combination of compression and cryotherapy (Cryo/Cuff ankle device) on parameters of ankle microcirculation in healthy volunteers over 30 min. In 21 volunteers (12 males, 29 +/- 10 years [incl. females], BMI 24 +/- 3) the Cryo/Cuff ankle device (AIRCAST, Summit, NJ, USA) was applied with continuous assessment of parameters of ankle microcirculation, such as tissue oxygen saturation (SO2), relative postcapillary venous filling pressures (rHb), and microcirculatory blood flow at 2- and 8-mm tissue depths during 30 min with the Oxygen-to-see System, a laser-Doppler-spectrophotometry-system (LEA Medizintechnik, Giessen, Germany). Superficial tissue oxygen saturation (SO2, 48 +/- 19 %) immediately dropped to 23 +/- 15 % (-52 %, p < 0.05) within the first 2 min after Cryo/Cuff activation with a consecutive slow decrease to 32 +/- 23 % (- 32 %, p < 0.05 vs. baseline) after 30 min. Deep SO2 (8 mm, 69 +/- 5 %) did not change within 30 min of Cryo/Cuff application (70 +/- 4 %, n.s.). Superficial postcapillary venous filling pressures (61 +/- 17 relative units) showed an immediate and sustained decrease after Cryo/Cuff application within four minutes to 37 +/- 18 relative units (-39 %, p < 0.05). Deep postcapillary venous filling pressures (85 +/- 20 relative units) dropped within the first four minutes of Cryo/Cuff application to 68 +/- 19 relative units (-20 %, p < 0.05). Superficial microcirculatory blood flow (21 +/- 36 relative units) decreased significantly to 7 +/- 5 relative units after 30 min (-69 %, p < 0.05 vs. baseline). Deep microcirculatory blood flow at 8 mm tissue depth (63 +/- 43 relative units) significantly decreased over the 30 min to 39 +/- 23 relative units (-47 %, p < 0.05 vs. baseline). Using the Oxygen-to-see system we could demonstrate significant effects of the Cryo/Cuff device on the ankle level in healthy volunteers with reduced superficial tissue oxygen saturation with preserved deep tissue oxygen saturation, reduced superficial and deep postcapillary venous filling pressures, and reduced superficial and deep microcirculatory blood flow as a function of time. Further clinical studies are mandatory to elucidate the effects of the Cryo/Cuff device on the microcirculatory environment in injured ankles.