[S2k-Guideline on Meniscus Diseases: from Aetiology to Scoring]. / S2k-Leitlinie Meniskuserkrankung: Von der Ätiologie bis zum Scoring.

The number of patients with meniscal injuries is increasing constantly, but the treatment algorithms are undergoing continuous change. The effects of meniscal surgery, as well as the indications for the procedure, are currently a matter of heated debate. Various German speaking associations addressing topics related to the knee have joined forces to develop guidelines for the diagnosis, evaluation and therapy of meniscal lesions. The hope is that this first of two publications will shed light on some of the ongoing issues and offer guidance to health care professionals treating these patients.

[Hip fractures in the elderly : Osteosynthesis versus joint replacement]. / Hüftgelenknahe Frakturen im hohen Lebensalter : Osteosynthese vs. Gelenkersatz.

BACKGROUND: Osteoporotic fractures of the femoral neck and trochanteric region pose an ever-expanding existential problem both for the individual and for society. Despite numerous innovations and advances regarding implant design, mortality and the systemic and mechanical complication rates remain high. OBJECTIVES: Depiction of treatment options for femoral neck fractures and trochanteric femur fractures in the elderly comparing joint replacement and osteosynthesis. METHODS: A search of the Medline, Embase and Cochrane databases was carried out focusing on hip fracture treatment. Randomized or quasi-randomized controlled trials, meta-analyses and reviews comparing joint replacement or fixation implants in the elderly were included. RESULTS: Displaced fractures of the femoral neck often require total joint arthroplasty whereas trochanteric fractures are amenable to internal fixation. Cemented total hip replacement as opposed to cementless techniques is recommended in the elderly and yields good functional results in active patients. Hemiarthroplasty is the treatment of choice in infirm patients with multiple comorbidities and cognitive impairment. Trochanteric fractures (AO/OTA types A1 and A2) can be successfully treated with intramedullary or extramedullary fixation. Adequate reduction and stable fixation are prerequisites for uneventful healing. A meticulous operative technique can prevent iatrogenic complications. CONCLUSION: In summary, there are many parameters affecting the outcome in the treatment of fragility and hip fractures. Technical features as well as surgeon characteristics play an important role and the ultimate solution has yet to be developed. Even though fracture morphology may indicate a specific treatment option, patient characteristics play an important role in decision-making. The development of centers of fragility fracture care in Germany could help to lower the complication rate and increase quality of life in hip fracture patients in the future.

Muscle strength of the lumbar spine in different sports.

BACKGROUND: The ability to stabilize the body center (core stability) against dynamic movements of the extremities and capability to absorb repetitive loading forces in the trunk play a crucial role in any professional sport specific performance. OBJECTIVE: The aim our cross sectional level of evidence 3 study was to determine, if athletes of different sport disciplines showed specific trunk strength profiles and if these were different from a control group. METHODS: 20 ironman triathletes, 18 amateur volleyball and 18 amateur soccer players were tested for their individual isometric strength of the lumbar spine in three planes of motion using a standartized test device. RESULTS: The test profile revealed similar strength parameters for extension and lateral flexion to the left in each of the 3 study groups tested. The lateral flexion to the right was significantly stronger than in the control group (soccer > volleyball > triathlon). In all 3 groups, weaknesses were found in the abdominal musculature, showing highly significant differences in flexion and bilateral rotation compared to the control group (p=0.001). CONCLUSIONS: Our study shows that sports specific training for triathlon, as well as the team sports soccer and volleyball, does not lead to balanced trunk musculature and core stability. In consequence predisposing injury and muscle dysbalane can trigger pain syndromes.

Biomechanical investigation of the stabilization principle of the Latarjet procedure.

PURPOSE: The purpose of the study was to determine the biomechanical status of the different components of the Latarjet procedure. The anterior capsule reconstruction with the transferred coracoacromial ligament (CAL) and the necessity of an intact subscapularis tendon were of particular interest. We hypothesized that the anterior capsule reconstruction will have a significant effect and that the Latarjet procedure will lose its stabilizing effect if the subscapularis tendon is torn. METHODS: Stability testing of 12 human shoulder specimens was performed. After testing of the intact joint, a combined anterior glenoid and capsule defect was set arthroscopically. Then the Latarjet procedure was performed using an open approach and tested with and without loading of the conjoint tendons (10 N). Afterwards, the specimens were distributed into two groups and the Latarjet technique was reduced stepwise: dissection of the CAL, dissection of the conjoint tendons (group A); reduction of the coracoid segment, dissection of the subscapularis tendon (group B). Biomechanical testing was performed for each condition in two positions: 60° of glenohumeral abduction with neutral rotation and with 60° of external rotation; each with a passive humerus load of 30 N in the anterior, inferior and anteroinferior direction. RESULTS: The Latarjet technique with load applied to the conjoint tendons significantly reduced translation compared with the defect condition for all tested positions in all directions. In group A, the CAL-dissection led to a significant increase of anterior translation (+5.0 mm, p = 0.003) and inferior translation (+7.3 mm, p = 0.025) in neutral rotation and of anterior translation in 60° of external rotation (+4.4 mm, p = 0.034). In group B, the reduction of the coracoid bone down to the coracoid tip resulted in a significant increase of only the anterior translation in abduction and 60° of external rotation (+4.5 mm, p = 0.05). In contrast, the detachment of the subscapularis tendon led to a significant increase of translation in all testing positions except the inferior direction in the neutral rotation. CONCLUSIONS: We found the anterior capsule reconstruction to represent a significant contribution to the stabilizing effect of the Latarjet procedure, whereas a deficiency of the subscapularis tendon eliminates its effect. CLINICAL RELEVANCE: We recommend to perform the Latarjet technique with an anterior capsule reconstruction (e.g. CAL transfer) and with a transfer of the coracoid bone block rather than a transposition of the coracoid tip. Furthermore, we were able to show that an intact subscapularis tendon is a necessary prerequisite for a reliable stabilization.

[Clinical and gait analytical investigation of valgus knee bracing in therapy for medial degenerative joint disease of the knee]. / Klinische und ganganalytische Untersuchung einer valgisierenden Kniegelenkentlastungsorthese in der Therapie der medialen Gonarthrose.

GOALS: The non-operative treatment of medial degenerative joint disease of the knee has proven to be difficult due to the underlying deformity and the pathological mechanical loading. Valgus knee bracing offers the possibility to directly address the mechanical deficit. The aim of this study was to analyse whether or not part-time valgus knee bracing in patients with medial osteoarthrits can effectively reduce knee pain and lead to reproducible changes in the gait analysis in comparison to an elastic knee bandage and an untreated control group. MATERIAL AND METHODS: In a prospective trial, 33 patients with symptomatic medial osteoarthritis of the knee joint with a minimum of grade 2 according to the radiographic classification of Kellegren & Lawrence were randomised into a treatment group with a valgus brace (n = 13; M4 OA®, Medi) and an elastic knee bandage (n = 10; Genumedi®, Medi). Both supportive devices were to be applied for 2-4 hours per day, especially during activity. The control group (n = 10) consisted of untreated individuals. The deviation of the leg axis and the degree of degenerative joint disease were evaluated radiographically at the onset of the study by a standing whole leg X-ray. The evaluation at the beginning of the study and after 16 weeks consisted of a clinical examination including various knee scores (Insall score, Lequesne score, HSS score, Tegner score, WOMAC, and VAS for pain). Additionally, at both times a 3-dimensional, instrumented gait analysis was carried out to document the joint angles of the affected knee in all planes. The obtained knee joint angles from all groups at both time points were compared to a control group of healthy persons without a history of knee pain by qualitative measurement. RESULTS: Radiographically, the medial deviation of the load axis from the knee joint centre (MAD) was 29 mm. In 27 patients we found a combination of femoral, intra-articular and tibial changes contributing to the varus alignment. The joint line conversion angle (JLCA) was pathological in all subjects. Clinically, in 4 of 5 subjective and objective scores (Insall score, Lequesne score, Tegner score, WOMAC, and VAS for pain) a statistically significant improvement of the symptoms, joint function and activity level thanks to the application of the corrective valgus knee brace was documented after 16 weeks. The knee bandage also led to an improvement, but only in 2 scores (Insall score, Tegner score). No changes were documented for the control group. The gait analysis of the orthosis group revealed an improvement in the extension and flexion angles (sagittal plane) and the knee rotation angles (horizontal plane) when compared to a control group. CONCLUSION: The correction obtained by this knee orthosis, which places a valgus stress on the medially osteoarthritic knee, is an effective addition to the conservative treatment protocols and is superior to the isolated use of an elastic knee bandage. Further research is warranted to evaluate the longevity of such treatment and to further improve the technique of gait analysis by the development of quantitative parameters.

[Muscle strength of the cervical and lumbar spine in triathletes]. / Das muskuläre Profil der Halswirbelsäule und der Lendenwirbelsäule bei Langstreckentriathleten.

AIM: The goal of this study was to analyse the muscle strength of the cervical and lumbar spine in ironman triathletes. The values were compared to the results obtained from a reference group. The test of the triathletes was carried out in an attempt to define a specific strength profile for these athletes. METHOD: In this study, 20 long-distance triathletes (∅ 37.3 ± 7.6 years of age, ∅ 1.80 ± 0.1 m, ∅ 73.7 ± 6.0 kg) were evaluated with regard to their individual and sport-specific strengths of the cervical spine in 2 planes and of the trunk strengths in all 3 planes of motion. The trunk strength profile of the triathletes revealed good average results in the trunk extensors and the lateral flexors of the left trunk. The reference group is the data base of the company Proxomed®, Alzenau. It is based on results of 1045 untrained, symptom-free subjects of different ages. RESULTS: Lumbar extension: The extension of the force values shows no significant difference from the reference group. Lumbar flexion: The flexion tests show highly significantly lower force values (5.025 ± 0.81 N/kg vs. 6.67 ± 0.6 N/kg) than the reference group. Flexion/extension: In the sagittal plane values for the triathletes demonstrate an imbalance in muscle strength ratios. The abdominal muscles turn in relation to the back extensor muscles too weakly to be very significant. Lumbar rotation: The force values of the athletes in both directions (right: 6.185 ± 1.46 N/kg, left: 7.1 ± 1.57 N/kg vs. 10.05 ± 0.34 N/kg) are highly significantly (p ≤ 0.001) lower than the reference values. Ratio of rotation left/right: The ratio of left/right rotation in the reference group is set at 1 and thus shows an equally strong force level between the two sides. Lumbar lateral flexion: The triathletes do not show any significant differences between the force values. Compared to the reference group there is no significant difference to the left side flexion. In the lateral bending the athletes have significantly better values than the reference group. Ratio of lateral left/right: In the reference group the ratio is set at 1. For triathletes, it shows an average value of 0.93. This difference is not significant. Cervical extension: The extension of the force values (1.96 ± 0.59 N/kg vs. 3.03 ± 0.24 N/kg) shows a highly significant difference from the reference group. Cervical flexion: In flexion (1.3 ± 0.42 N/kg vs. 2.17 ± 0.22 N/kg) triathletes have highly significantly lower strength values than the reference group. Flexion/extension: The triathletes did not differ significantly from the reference values (0.69 ± 0.23 and 0.72 ± 0.08). Lateral cervical spine: In comparison to the reference group (left: 1.67 ± 0.48 N/kg, right: 1.55 ± 0.46 N/kg vs. 2.36 ± 0.15 N/kg) in which there is left/right lateral flexion, there is a highly significant difference. Right lateral flexion is weaker than the left. Ratio of lateral left/right: The triathletes have a significant imbalance in the lateral flexion of the cervical spine compared to the reference group (1.07 ± 0.15 to 1). CONCLUSION: In conclusion, in the triathlon there is a specific stress that is obviously not an adequate stimulus for the muscles of the cervical spine in order to achieve a balanced musculature and the athletes should be advised to practice a preventive approach with regard to these areas.

[Comparison of trunk muscle strength of soccer players with and without low back pain]. / Vergleich der Rumpfmuskelkraft von Fussballspielern mit und ohne Rückenschmerzen.

AIM OF THE STUDY: Low back pain in soccer players is one of the frequently appearing disorders caused by overuse. Myogenic dysbalances are under discussion as possible reason for this problem. In the present study the muscular strength profile of the trunk musculature of soccer players with and without low back pain was evaluated. The results of the asymptomatic players were compared to those of players with low back pain; furthermore, the collected data were compared to those of an asymptomatic reference group. The question posed was whether soccer players show a specific strength profile caused by the special, sports-specific requirements and whether this strength profile differs between players with and without low back pain. METHOD: In the present study the isometric maximal strength of 18 soccer players with and 18 soccer players without low back pain was measured in all 3 planes. The reference group was provided by the Proxomed company, which had previously analysed 1045 healthy untrained individuals of various age groups. RESULTS: The soccer players showed a sport-specific profile for the musculature, which was determined by a significant reduction of the flexion and rotation strength (flex: Ø 5.21 N/kg vs. Ø 6.49 N/kg; Ø 5.78 N/kg vs. Ø 6.66 N/kg respectively; rotation: left 7.09 N/kg, right 8.69 N/kg vs. left/right 10.1 N/kg; left 7.22 N/kg, right 8.24 N/kg vs. left/right 10.0 N/kg, respectively) as well as by an increased lateral flexion strength to the right-hand side in comparison to the reference group (lat. flex. right: 9.87 N/kg, respectively, 10.67 N/kg vs. 8.3 N/kg). A statistically significant correlation between the muscular activity in the trunk stability of soccer players with and without low back pain could not be shown. CONCLUSION: Obviously sports-specific training with additional specific training of the trunk muscles is not sufficient for the development of a balanced strength of trunk musculature. In the present study an influence of the performance of the trunk musculature on the incidence of low back pain could not be shown.

[Orthopedic and trauma surgery in the German-DRG-System 2009]. / Orthopädie und Unfallchirurgie im G-DRG-System 2009.

BACKGROUND: The German DRG-System was advanced into version 2009. For orthopedic and trauma surgery significant changes concerning coding of diagnoses, medical procedures and concerning the DRG-structure were made. METHODS: Analysis of relevant diagnoses, medical procedures and G-DRGs in the versions 2008 and 2009 based on the publications of the German DRG-institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). RESULTS: Changes for 2009 focussed on the development of DRG-structure, DRG-validation and codes for medical procedures to be used for very complex cases. The outcome of these changes for German hospitals may vary depending in the range of activities. CONCLUSION: G-DRG-System gained complexity again. High demands are made on correct and complete coding of complex orthopedic and trauma surgery cases. Quality of case-allocation within the G-DRG-System was improved. Nevertheless, further adjustments of the G-DRG-System especially for cases with severe injuries are necessary.

In vitro interface and cement mantle analysis of different femur stem designs.

The aim of this study is to define stem design related factors causing both gaps in the metal-bone cement interface and cracks within the cement mantle. Six different stem designs (Exeter; Lubinus SP II; Ceraver Osteal; Mueller-straight stem; Centega; Spectron EF) (n=15 of each design) were cemented into artificial femur bones. Ten stems of each design were loaded, while five stems served as an unloaded control. Physiologically adapted cyclical loading (DIN ISO 7206-4) was performed with a hip simulator. After loading both interfaces and the bone cement itself were analysed regarding gaps and cracks in the cement mantle. Significant differences between the stem designs concerning gaps in the metal-bone cement interface and cracks in the cement mantle became apparent. Additionally, a high correlation between gaps in the metal-bone cement interface and cracks within the cement mantle could be proven. Gaps in the metal-bone cement interface but no cracks within the cement mantle were seen in the unloaded specimens. Differences between the unloaded control groups and the cyclical loaded stems regarding the longitudinal extension and width of gaps in the metal-bone cement interface were obvious. The designs of cemented femoral stems have an influence on both the quality of the metal-bone cement contact and the failure rate of the cement mantle. Less interface gaps and less cement defects were found with anatomically formed, collared, well-rounded stem designs without undercuttings.

[Orthopedic and trauma surgery in the German DRG system 2008]. / Orthopädie und Unfallchirurgie im G-DRG-System 2008.

BACKGROUND: The German DRG (diagnosis-related groups) system has been modified and updated into version 2008. For orthopedic and trauma surgery significant changes concerning coding of diagnoses, medical procedures and the DRG structure were made. The modified version has been analyzed in order to ascertain whether the DRG system is suitably qualified to fulfill the demands of the reimbursement system or whether further improvements are necessary. METHODS: Analysis of the severity of relevant side-effect diagnoses, medical procedures and G-DRGs in the versions 2007 and 2008 was carried out based on the publications of the German DRG institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). RESULTS: Changes for 2008 focused on the development of DRG structure, DRG validation and codes for medical procedures. The outcome of these changes for German hospitals may vary depending on the range of activities. CONCLUSIONS: G-DRG system has become even more complex and the new regulations have also resulted in new problems associated with complications.. High demands are made on correct and complete coding of complex orthopedic and trauma surgery cases. Quality of case allocation within the G-DRG system has been improved. Nevertheless, further improvements of the G-DRG system are necessary, especially for cases with severe injuries.

Surface coating to improve the metal-cement bonding in cemented femur stems.

INTRODUCTION: Hydrolytic debonding of the metal-cement interface is one of the main reasons for aseptic loosening in cemented hip arthroplasty. MATERIALS AND METHODS: BiContact femur stems (CoCrMo-/TiAl6V4-alloy) were coated by a silica/silane interlayer coating system. The stems were cemented into artificial femurs. The cyclical loading (DIN ISO 7206-4) was performed within a hip-simulator. Uncoated stems (CoCrMo-/TiAl6V4-alloy) were prepared and loaded the same way. After loading, the metal-cement and the bone-cement interfaces were analysed. Unloaded uncoated and unloaded coated BiContact stems served as a control. RESULTS: The coated loaded stems showed a significant reduction in debonding and cement failure (P < or = 0.05). A high correlation was documented between debonding and cement failure (rSpear> or = 0.9). There was no significant difference between CoCrMo- and TiAl6V4-stems (P > or = 0.05). CONCLUSION: The silica/silane coating significantly decreased hydrolytic debonding at the metal-bone cement interface with consecutively less cement failure.

[Hand surgery in the German DRG System 2007]. / Die Handchirurgie im G-DRG-System 2007.

BACKGROUND: Hand surgery often needs only a short length of stay in hospital. Patients' comorbidity is low. Many hand surgery procedures do not need inpatient structures. Up until 2006 special procedures of hand surgery could not be coded. The DRG structure did not separate very complex and less complex operations. Specialized hospitals needed a proper case allocation of their patients within the G-DRG system. RESULTS: The DRG structure concerning hand surgery increased in version 2007 of the G-DRG system. The main parameter of DRG splitting is the complexity of the operation. Furthermore additional criteria such as more than one significant OR procedure, the patients' age, or special diagnoses influence case allocation. A special OPS code for complex cases treated with hand surgery was implemented. CONCLUSION: The changes in the DRG structure and the implementation of the new OPS code for complex cases establish a strong basis for the identification of different patient costs. Different case allocation leads to different economic impacts on departments of hand surgery. Whether the new OPS code becomes a DRG splitting parameter has to be calculated by the German DRG Institute for further DRG versions.

[Total hip replacement in the G-DRG-system]. / Hüftgelenks-Endoprothetik im DRG-System.

AIM: Due to the continuing increase in life expectancy, the ageing process of the German population in general and the high demands placed on activity levels and quality of life today, the demand for primary and secondary joint replacement surgery continues to increase. To distribute the economic and medical resources properly, while still making technical and surgical innovations available to a broad public, hospitals must be able to adequately finance these procedures with the help of the proper diagnosis related groups. METHOD: The development of the German DRG-system over the past years, as well as the new calculation for the year 2006 are to be reviewed and analysed in this article with this in mind. RESULTS: An improvement in the degree of differentiation between the individual procedures can be documented. CONCLUSION: Whether or not these changes will ensure the long-term financial survival of the German health care system will remain to be seen.

[Orthopedic and trauma surgery in the German DRG System 2007]. / Unfallchirurgie und Orthopädie im G-DRG-System 2007.

BACKGROUND: The German Diagnosis-Related Groups (DRG) System was further developed into its 2007 version. For orthopedic and trauma surgery, significant changes were made in terms of the coding of diagnoses and medical procedures, as well as in the DRG structure itself. The German Societies for Trauma Surgery and for Orthopedics and Orthopedic Surgery (Deutsch Gesellschaft für Unfallchirurgie, DGU; and Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie, DGOOC) once again cooperated constructively with the German DRG Institute InEK. RESULTS: Among other innovations, new International Classification of Diseases (ICD) codes for second-degree burns were implemented. Procedure codes for joint operations, endoprosthetic-surgery and spine surgery were restructured. Furthermore, a specific code for septic surgery was introduced in 2007. In addition, the DRG structure was improved. Case allocation of patients with more than one significant operation was established. Further DRG subdivisions were established according to the patients age and the Patient Clinical Complexity Level (PCCL). CONCLUSIONS: DRG developments for 2007 have improved appropriate case allocation, but once again increased the system's complexity. Clinicians need an ever growing amount of specific coding know-how. Still, further adjustments to the German DRG system are required to allow for a correct allocation of cases and funds.

[Osteochondrosis dissecans of the hip in adults--differential diagnosis of free joint bodies--case report]. / Osteochondrosis dissecans der Hüfte beim Erwachsenen -- Differenzialdiagnostik freier Gelenkkörper -- Fallbeschreibung.

The causes of hip pain in adults can vary greatly. We present the case of a 44-year-old woman with recurrent hip pain over a period of years. Medical history and clinical examination did not provide any decisive information. The X-rays revealed a loose body in the cavity of the hip joint. The MRI scan made the following differential diagnosis plausible: osteochondrosis dissecans coxae, osteochondroma and chondromatosis. The final diagnosis of osteochondrosis dissecans coxae was confirmed by surgical dislocation of the hip as modified by Ganz and histological examination of the loose body. This case supports the importance of including rare lesions in the differential diagnostic work-up of joint pain. The advantages of the offset operation as modified by Ganz versus arthroscopy of the hip are outlined.

[Revision surgery for knee prostheses using the DRG system]. / Wechseloperationen in der Kniegelenkendoprothetik im DRG-System.

Due to an increasing life expectancy and earlier primary implantation of total knee replacements, the number of patients requiring revision surgery in Germany is increasing by 7% every year. These revision cases belong to the most treatment and cost intensive operations in joint replacement surgery. Presently, the description of these procedures in the German DRG system, which defines the financial reimbursement for the hospitals, is changing yearly with the development of new catalogues. The changes made from 2003 to 2005 are outlined in the following article. A correct depiction of the treatment and procedures required in such cases is a prerequisite for an adequate reimbursement. In the long-term, hospitals will only be able to offer such complex treatment forms if the financial compensation correctly reflects the costs incurred.

[epiDRB--a new minimally invasive concept for referencing in the field of computer-assisted orthopaedic surgery]. / epiDRB -- ein neues minimal-invasives Konzept für die Referenzierung im Rahmen der Computer-assistierten orthopädischen Chirurgie.

AIM: Optoelectronic navigation for computer-assisted orthopaedic surgery (CAOS) is based on a firm connection of bone with passive reflectors or active light-emitting diodes in a specific three-dimensional pattern. Even a so-called "minimally-invasive" dynamic reference base (DRB) requires fixation with screws or clamps via incision of the skin. Consequently an originally percutaneous intervention would unnecessarily be extended to an open procedure. Thus, computer-assisted navigation is rarely applied. Due to their tree-like design most DRB's interfere with the surgeon's actions and therefore are at permanent risk to be accidentally dislocated. Accordingly, the optic communication between the camera and the operative site may repeatedly be interrupted. The aim of the research was the development of a less bulky, more comfortable, stable and safely trackable device that can be fixed truly percutaneously. METHOD: With engineering support of the industrial partner the radiolucent epiDRB was developed. It can be fixed with two or more pins and gains additional stability from its epicutaneous position. The intraoperative applicability and reliability was experimentally tested. RESULTS: Its low centre of gravity and its flat design allow the device to be located directly in the area of interest. Thanks to its epicutaneous position and its particular shape the epiDRB may perpetually be tracked by the navigation system without hindering the surgeon's actions. Hence, the risk of being displaced by accident is minimised and the line of sight remains unaffected. CONCLUSION: With the newly developed epiDRB computer-assisted navigation becomes easier and safer to handle even in punctures and other percutaneous procedures at the spine as much as at the extremities without an unproportionate amount of additional trauma. Due to the special design referencing of more than one vertebral body is possible at one time, thus decreasing radiation exposure and increasing efficiency.

[Minimally-invasive computer-assisted fluoroscopic navigation for kyphoplasty]. / Minimal-invasive Computer-assistierte fluoroskopische Navigation der Kyphoplastie.

AIM: The transpedicular placement of a hollow needle into vertebral bodies for kyphoplasty requires utmost accuracy and thereby permanent multiplanar X-ray control. Facing the increasing number of vertebral compression fractures, the aim of this work was the implementation of computer-assistance to optimise the issue. Prior to clinical implementation, experimental trials were undertaken to analyse the quality-improving options of the technique. METHOD: The virtual image of the planning and the puncture were correlated with the postoperative X-ray image of the needle. The real canal in the bone was then correlated with the preoperative planning in a CT-based 3D model and differences were calculated. As a measure of accuracy the deviation of the needle from the ideal intruding vector and the distance between its top and the centre of a predefined target were scrutinised and related to the indications of the navigation system. Operating time, radiation exposure and general applicability were additionally assessed. All data were compared with those of a conventional control group. RESULTS: Planning and navigation could be executed with high accuracy. With an exactly transpedicular approach, neural structures were safely circumnavigated without once missing the target. In the control group the distance fault was up to 9 mm. The navigated drilling differed from the ideal trajectory by 1 degrees to max. 4 degrees. Conventional C-arm control led to a divergence of 4 degrees to 8 degrees . Radiation exposure could be reduced through computer assistance by 76 % to a fourth of the conventionally resulting amount and the pure operating time thereby decreased by 40 %. The inconvenient course of repeated positioning of the C-arm was overcome. CONCLUSION: In challenging cases of deteriorated anatomy and difficult radiomorphologic orientation, especially of the lower thoracic spine, the CAOS-procedure succeeds in finding the optimal pedicular approach to the vertebral body, helps to avoid collateral damage and minimises the overall risk of the procedure. High accuracy and reduced radiation exposure justify the clinical use of fluoroscopic navigation for transpedicular instrumentation.

Anatomical and biomechanical investigations of the iliotibial tract.

Divergent descriptions of the anatomic location and biomechanical function of the iliotibial tract (IT) can be found in the literature. This study attempted to obtain exact data regarding the anatomic course and material characteristics including the biomechanical properties of this structure. The following were its aims: (1) anatomical investigations of the IT; (2) mechanical properties of the IT; (3) femoral head centralizing force of the IT and subligamentous forces in the height of the greater trochanter in different joint positions by using a custom-made measuring prosthesis and a subligamentous positioned sensor; (4) construction of a finite element model of the proximal femur including the IT and measuring the femoral neck angle under variation. The hip joints and IT in a total of 18 unfixed corpses were evaluated. We studied the anatomic relationship to surrounding structures, as well as the material properties with the help of tensile strength testing utilizing an uniaxial apparatus. During the test, a load-displacement curve was registered, documenting the maximum load and deformation of the IT. To measure the subligamentous pressure at the height of the greater trochanter, a custom-made sensor with a power-recording instrument was constructed. Furthermore, an altered hip prosthesis with a pressure gauge at the height of the femoral neck was used to measure the forces which are directed at the acetabulum. The investigations were done in neutral-0 position and ab/adduction of the hip joint of the unfixed corpse. In addition, we varied the femoral neck angle between 115 degrees and 155 degrees in 5 degrees steps. To confirm the subligamentous forces, we did the same measurements intraoperatively at the height of the greater trochanter before and after hip joint replacement in 12 patients. We constructed a finite element model of the proximal femur and considering the IT. The acquisition of the data was done at physiological (128 degrees), varus (115 degrees), and valgus (155 degrees) femoral neck angles. The influencing forces of the IT at the height of the greater trochanter and the forces at the femoral head or the acetabulum could be measured. Our anatomical investigations revealed a splitting of the IT into a superficial and a deep portion, which covers the tensor fasciae latae. The tensor fasciae latae has an insertion on the IT. The IT continues down the femur, passing over the greater trochanter without developing an actual fixation to the bone. Part of the insertion of the gluteus maximus radiates into the IT. The IT passes over the vastus lateralis and inserts at the infracondylar tubercle of the tibia or Gerdy's tubercle, at the head of the fibula, as well as at the lateral intermuscular septum. Portions also insert on the transverse and longitudinal retinaculum of the patella. Concerning the material properties of the IT, we found a structural stiffness of 17 N/mm extension on average (D = 17 N/mm). The subligamentous measurements at the height of the greater trochanter in the unfixed corpse and intraoperatively during hip joint replacement showed an increase of the forces during adduction and a decrease during abduction of the hip joint. We found thereby a maximum increase up to 106 N with 40 degrees adduction. Concerning the femoral neck angle, we can state that valgus leads to lower subligamentous forces and varus to higher subligamentous forces. The forces directed at the acetabulum, which were measured by the prosthesis with a sensor along the femoral neck, showed a decrease with varus angles and an increase with valgus angles. The highest force of 624 N was measured with 40 degrees adduction and an angle of 155 degrees. The finite element model of the proximal femur showed a sole hip joint-centralizing force of the IT of 655 N with a femoral neck angle of 128 degrees after subtraction of the gluteal muscle force and the body weight. At 115 degrees, we found an increase up to 997 N and a decrease to 438 N at 155 degrees. Concerning the resulting forces in the acetabulum, we found opposite forces in comparison with the force of the IT at the height of the greater trochanter: at 115 degrees, a femoral head-centralizing force of 1601 N; at 128 degrees, 2360 N; and at 155 degrees, 2422 N. By our investigations, we can approximately prove the hip joint-centralizing force of the IT. By variation of the femoral neck angle and the position of the hip joint, we can predict the subligamentous force of the IT and the resulting force at the femoral head or at the acetabulum. The intraoperative measurement of the subligamentous forces of the IT is a good monitoring mechanism for the persistent hip-centralizing function of the IT in the course of hip joint replacement. The surgeon has the opportunity to check the stability of the hip joint after replacement. The finite element model gives the opportunity to check the divergent relative strength by variation of the femoral neck angle and the tension of the IT. In this way, the changes in the forces induced by a displacement osteotomy could be estimated preoperatively.

Reactive knee and ankle joint arthritis: abnormal manifestation of Legionella pneumophila.

This case report demonstrates that active legionellosis is not always characterised by pulmonary symptoms and specific radiomorphological findings. Whereas the initial clinical presentation, as described in the literature, includes fever, cough, expectoration, extrapulmonary organ changes or typical laboratory findings, atypical manifestations such as reactive arthritis must be considered.