[Taking the anamnesis with a questionnaire - safe and effective]. / Die Anamneseerhebung mittels Fragebogen - sicher und effektiv.

INTRODUCTION: The anamnesis is essential for the treatment of any patient. On the other hand, the data are often of poor quality. The aim of the study was to work out whether a questionnaire which is filled out by the patient him-/herself is a reasonable tool for data acquisition. METHODS: In a level-IV trauma centre the data acquisition of 50 consecutive patients was performed with a questionnaire which was checked by a doctor. Excluding criteria were an age < 18 years, previous treatment in the clinic, a transfer from an external clinic or a caring institution and a dementia. The results were compared with the data of the 50 patients prior to the study start. RESULTS: We collected data about the general doctor, diseases, allergies, tobacco usage, drugs, operations and the familial situation. In all 7 fields the questionnaire raised more data than the oral survey; in 4 sections the difference was significant, in 3 (p > 0.05). DISCUSSION: A questionnaire is a reasonable, time-sparing tool for data acquisition of the individual anamnesis in a surgical clinic.

[Comparison of stability of plate fixateurs with parallel and oblique screw directions]. / Vergleich der Ausbruchfestigkeit winkelstabiler Plattensysteme bei paralleler und divergierender Schraubenlage.

INTRODUCTION: One of the main failure mechanisms of modern plate fixateurs is the tearing of the whole plate-screw construct out of the osteoporotic bone. The aim of this study was to show whether an oblique screw placement can improve the fixation of the plate to the bone. METHODS: A steel probe was fixed to a synthetic bone (Fa. Sawbones) with standard titanium fixed-angle screws in parallel and 55° oblique positioning. We tested the static tear force and the dynamic stability (force distance 1.4 or 1.6 mm, 610 and 900 N, frequency of force shift of 560 or 380/min). Endpoint was a visible tear of the artificial bone. In addition we performed a morphological analysis of the torn fragments. RESULTS: The maximal tear force was 2.04 kN (1.95-2.13) for oblique and 2.66 kN (2.55-2.77) for parallel placement (p < 0.05). With a parallel positioning a higher number of force shifts were performed before a visual tear appeared. With parallel positioning the screw canal was torn with an intact surrounding corticalis; in oblique positioning the threads remained intact, the corticalis was torn out with a wedge. DISCUSSION: An oblique screw positioning does not result in a higher tear force in modern plate fixateurs.

[Ultrasound-based treatment of proximal humerus fractures in children]. / Ultraschallbasierte Therapiesteuerung bei subkapitalen Humerusfrakturen im Wachstumsalter.

INTRODUCTION: The treatment of juvenile proximal humerus fractures is based on the extent of the deformity. The standard diagnosis with X-ray images in 2 directions is error-prone and can lead to a suboptimal treatment. The aim of this study was to evaluate if ultrasound imaging can improve the measurement of the deformity of proximal humerus fractures. MATERIAL AND METHODS: In a prospective, multicentre trial children aged 0-12 years with a suspected proximal humerus fracture were initially examined with a 10-MHz linear transducer in 4 directions and the maximum deformity was determined. Afterwards the standard X-rays were taken and the results of both methods compared. The certainty of both methods was compared with a standardised nominal scale. RESULTS: From 8/2010 to 5/2011 6 consultants in 4 hospitals examined 30 patients (16 m, 14 f, mean age 7.9 years). In 15 cases the ultrasound showed a larger deformation than the X-rays and in 2 cases vice versa. In 11 cases the measurement was identical 6 of which were undisplaced. The mean difference of the measurement of the deformity was + 8.6°, with 14.2° in the displaced fractures. The certainty of the ultrasound was rated significantly higher (p < 0.05) than that of radiography. DISCUSSION: With a correct technique the deformity cannot be overestimated by ultrasound means and the safeness is rated significantly higher in comparison to the X-ray imaging. It seems that ultrasound is a meaningful method to improve the measurement of the deformity of proximal humerus fractures in children. Deficiencies are found only in cases with massive deformities which demand a reduction and stabilisation.

[Uncertainty in the radiological evaluation of deformity in proximal humerus fractures]. / Unsicherheit bei der radiologischen Achsbestimmung proximaler Humerusfrakturen.

INTRODUCTION: The accurate measurement of the deformity of proximal humerus fractures is essential for a proper treatment, particularly in the growing bone. Due to the local pain the correct projection in standard X-rays is difficult to achieve and, in contrast to other joints, cannot be verified in the X-ray. Even with the correct projections a mismeasurement can occur when the rotation is 45° to both planes. The aim of this study was to objectify the error sources and reveal starting points for an improvement. MATERIAL AND METHODS: In a three-step study we initially developed a mathemathical formula in cooperation with the faculty of mathematics of the University of Duisburg-Essen. This formula was proved with X-ray imaging of a steel rod which was bent 120°, simulating a 60° deformity. X-ray images with different rotation and tilt were taken and compared with the values calculated with the above-mentioned formula. In the third step X-rays of a healthy shoulder in different rotation and tilt positions were presented to 2 orthopaedic and 3 radiological consultants. The aim was to determine the direction and amount of rotation and tilt. RESULTS: The first theoretical step resulted in a mathematical formula which describes the optical deformation based on real deformation, tilt and rotation. The evaluation showed a mean difference of 0.5° (0-1.2°) between the calculated and the measured values. In the third step, evaluation of the X-rays of a shoulder showed that two in 50 (4 %) of the values were correct, in additional 28 cases (56 %) the tendency of the direction of the rotation was correct, the extent of the rotation was missed by 19.6° (0-60°). Ante- and retroversion were evaluated correctly in nine cases (18 %), the extent was missed by a mean of 23° (0-50°). In seven cases (18 %) the tendency for rotation and ante-/retroversion was correct, in 11 cases (22 %) one or both aspects could not be evaluated, in additional 8 cases (16 %) the extent could not be estimated. DISCUSSION: Our results show that rotation and tilt of the proximal humerus cannot be estimated in shoulder X-rays and therefore a reliable measurement of the deformity of proximal humerus fractures is extremely unsafe. This problem is relevant for clinical practice because of the high likeliness of unaccurate projections in shoulder X-ray imaging after trauma. Especially for the growing bone the problem is evident, so that new ways of determining the deformity are mandatory.

[Proximal cut-out of the hip screw: cement augmentation as a minimally invasive rescue procedure]. / Zementaugmentation als minimalinvasive Rettungsoperation bei proximalem Cut-out von Hüftnägeln.

BACKGROUND: Cemented augmentation of osteosynthesis for the treatment of peritrochanteric fractures in elderly patients has been under discussion for years. We propose this option as a salvage procedure in cases of instability after standard osteosynthesis. MATERIAL AND METHODS: After reduction and optional re-osteosynthesis a Jamshidi needle is placed transcutanously or through the open wound cranio-lateral of the tip of the hip screw. Cement augmentation can be performed under fluoroscopic control. The patients were monitored for at least 7 months postoperatively to rule out a redislocation. RESULTS: From 1/2009 to 1/2011 we treated 6 patients (5 female, 1 male, age 83.8 [79-94] years). We performed 4 augmentations and 2 augmentations with additional re-osteosynthesis. OP time was 26.8 (13-45) minutes. The revision was performed 9.7 (4-14) days after the osteosynthesis. Within 14.7 (7-28) months no redislocation and no surgical complication occurred. CONCLUSION: Even with a small patient number the good results show the potential of this minimally invasive technique. In our opinion this option allows a fast and technically easy salvage procedure without blocking of further treatment options like a prosthesis.

A morphometric cadaver study of the anterior lumbar epidural space.

INTRODUCTION: Free disc fragments end often up in the concavity of the anterior epidural space. This space consists of two compartments. The discrepancy between the impressive magnetic resonance imaging findings, clinical symptoms in patients and the problem of treatment options led us to the anatomical determination of anterior epidural space volumes. MATERIALS AND METHODS: For the first time, the left and right anterior epidural volume between the peridural membrane and the posterior concavity of the lumbar vertebral bodies L3-S1 were determined for each segment. A CT scan and a polyester resin injection were used for the in vitro measurements. RESULTS: The volumes determined in human cadavers using this method ranged from 0.23 ccm for L3 to 0.34 ccm for L5. The CT concavity volume determination showed this increase in volume from cranial to caudal, as well. CONCLUSION: This volume is large enough to hold average-sized slipped discs without causing neurological deficits. A better understanding of the anterior epidural space may allow a better distinction of patient treatment options.

[Does osteoporosis lead to reduction the primary stability of cementless hip cups?]. / Führt Osteoporose zu einer Reduktion der Primärstabilität zementfreier Hüftpfannen?

BACKGROUND: Cementless hip cups require adequate primary stability in order to achieve osseointegration. Depending on implant design, a different biomechanical behavior in osteoporotic bone and in bone with normal bone mineral density might be expected. MATERIAL AND METHODS: The micromovement between bone and implant was determined in macerated human hip acetabula with reduced and with normal bone density for two different cementless screwed cups and two different cementless press-fit cups. The bone mineral density was assessed by means of Q-CT and 20 implantations were performed for each acetabulum with reduced and with normal bone density. RESULTS: Screwed cups showed significantly less micromovement than press-fit cups. The average micromovement of all cups, with the exception of the Monoblock cup, remained below the value of 100 µ, the upper limit for successful osseointegration. Values of over 200 µ were measured only for the Monoblock cup and only in some of the tests. There was no significant difference between the micro-movement in acetabula with reduced bone mineral density and with normal bone. CONCLUSION: Impaired osseointegration in osteoporotic bone because of increased micromovement is not to be expected in the investigated cementless hip cups as no relevant differences in micromovement were found between normal and osteoporotic bone stock. On the basis of the good clinical results with the Monoblock cup, the upper limit of 100 µ of micromotion for osseointegation in macerated bone is probably set too low.

[Rupture of the anterior cruciate ligament. Diagnostics and therapy]. / Ruptur des vorderen Kreuzbands. Diagnostik und Therapie.

Rupture of the anterior cruciate ligament (ACL) is the most common ligamentous knee injury. The knee is stabilized by the cruciate ligaments and the collateral ligaments. The ACL originates from the inner surface of the lateral condyle of the femur, runs in an anterior medial direction and inserts at the tibial plateau in the intercondyle area. The most common injury is an indirect knee trauma, typically a joint torsion in sports. Patients often describe a snapping noise followed by hemarthrosis. Concomitant injuries are lesions of the medial collateral ligament, the medial meniscus (unhappy triad) and chondral fractures. The age peak is between 15 and 30 years with a higher incidence in females. The cardinal symptom of the ACL rupture is the giving way phenomenon. The clinical diagnosis is provided by a positive Lachman test, a positive pivot shift test and the anterior drawer test. Fractures can be excluded by X-ray examination. Magnetic resonance imaging (MRI) allows the evaluation of the internal knee structures. ACL repair is carried out by arthroscopically assisted bone-tendon-bone or semitendinosus grafting techniques. Early rehabilitation is important for a good functional outcome.

[Cementing techniques in hip arthroplasty: an overview]. / Zementiertechnik in der Endoprothetik des Hüftgelenks: eine Ubersicht.

For decades the cemented anchorage of hip prostheses, especially for elderly patients, is the standard procedure. The cementing technique has turned out to be the determining factor for the survival of the implant. In the last few years developments in this field have been able to further improve the long-term survival. Established components of the modern cementing technique are vacuum-mixed cements, medullary canal plugs, centralising elements und the use of jet-lavages. The design of the cemented shaft depends on the more important surface finish. In the most clinical studies, polished shafts turned out to be slightly superior as compared to shafts with rough surfaces.

[Cement-in-cement hip revision with a long-stemmed femoral component]. / Zement-in-Zement-Hüftrevision mit einem zementierten langen Prothesenstiel.

Revision hip surgery often requires individualized techniques and implants. We report on a case of failed femoral revision in an extensively cemented femur with a concomitant proximal and dorsal femoral bone defect. We advocate the clinically effective revision procedure of antegrade drilling of the stable cement mantle and use of a cemented long-stemmed femoral component. This cement-in-cement revision technique is discussed along with the pertinent literature.

[Uncemented arthroplasty of the hip]. / Zementfreie Endoprothetik des Hüftgelenks.

Prognosis of cemented total hip replacement seems to be excellent for elderly patients. In younger age the outcome is less favourable and early revision is more common. Thus, different concepts with better prognosis and preservation of bone stock for possible revisions were needed. After more than 30 years of application with excellent short-term and long-term results, uncemented total hip arthroplasty is nowadays generally regarded as the standard procedure for younger patients. New bone-preserving implants, such as surface replacement or short-stemmed femoral shaft prostheses, have been introduced especially for younger patients. Some of these new procedures are still under development, and the long-term results of new implant concepts have to be evaluated over the next decades. Regarding recently published scientific studies an overview about non-cemented total hip arthroplasty is given and current concepts and developments are presented.

The compression-rotation stem: an experimental study on the primary stability of a new revision hip stem.

In revision hip arthroplasty with bone defects of the proximal femur, a well-established treatment method is reconstruction with impacted allograft spongiosa chips and cemented implantation of a polished stem. Building on this principle of impacted bone grafting, a femoral implant, which is suited to uncemented hip arthroplasty as well as for uncemented revisions, was designed. This so-called compression-rotation stem (CR stem) is collarless and has flanks which compress the impacted bone chips during implantation and thereby increase the rotational stability. To evaluate the primary stability of this new shaft after impaction grafting, the micromotion was determined using six motion transducers. Under physiological loading conditions with simulation of the muscle activities at the proximal femur the application was dynamically loaded for 15,000 cycles with 1000 +/- 500 N and afterwards for 5000 cycles with 1300 +/- 1000 N. Uncemented CR stems and the control Exeter stems were implanted in a standardized manner according to the X-Change method. Therefore they were implanted into artificial femora that had been previously resected, hollowed, and filled with impacted human spongeous bone allograft to simulate bone defects. Subsequently, the femora were loaded under identical conditions and the micromotions measured. In the majority of the implantations, no significant differences could be found. In conclusion, similar clinical results for the two stems should be expected.

Selective inhibition of platelets by the GPIIb/IIIa receptor antagonist Tirofiban reduces leukocyte-endothelial cell interaction in murine antigen-induced arthritis.

OBJECTIVE: Inflammation is associated with the invasion of leukocytes into affected tissues and with the up-regulation of platelet activation and adhesion. Assuming that leukocyte accumulation is linked to platelet aggregation, the aim of our study was to examine the effects of selective platelet inhibition by the glycoprotein (GP) IIb/IIIa receptor antagonist Tirofiban on the leukocyte-endothelial cell interaction. MATERIAL AND METHODS: We used the model of antigen-induced arthritis (AiA) to induce inflammatory changes in the synovial microcirculation. Ex vivo labelled platelets and in vivo fluorescence-labelled leukocytes were visualized by intravital microscopy (IVM). C57/Bl6 mice were allocated to four groups; two control groups with saline or Tirofiban and two groups with AiA that also received either saline or Tirofiban (0.5 microg/g BW) intravenously. RESULTS: There was no significant change in platelet- or leukocyte- endothelial cell interaction in the endothelium in healthy control animals. In contrast, after selective inhibition of platelets, the platelet- and leukocyte-endothelial cell interaction was significantly reduced in arthritic mice and reached the level of the healthy control groups. CONCLUSION: Selective platelet inhibition by Tirofiban resulted in reduced leukocyte-endothelial cell interactions in AiA. Consequently, platelets contribute to leukocyte adhesion in AiA via GPIIb/IIIa and therefore platelet inhibition could become an additional therapy option in chronic arthritic disease.

[Hip dislocation following THA]. / Hüftluxation nach Hüftgelenktotalendoprothesenimplantation.

In the event of a hip dislocation following THA analysis of its mechanism is the main priority. In addition, the time since the operation and the direction of the dislocation need to be taken into account. When the cause of the dislocation is analysed the formation of the neocapsule plays a part at least in the case of early dislocations (within the first 6 weeks after the operation). Most dislocations happen during this postoperative period, and these can usually be treated nonoperatively by closed reduction with only a short period of general anaesthesia. Late dislocations (in the 7th and subsequent postoperative week) generally occur because of malpositioning or migration of the components of the prosthesis and quite often do need operative treatment. Dislocation after implantation of a total hip replacement is a serious complication; it should be treated quickly, and initially it confronts the operator with many unanswered questions, from the causes to their treatment.

Proximal loading of the femur leads to low subsidence rates: first clinical results of the CR-stem.

INTRODUCTION: A new femoral stem was developed with a design that leads to compression of cancellous bone in the calcar region which results in proximal loading. The cross-sectional design of the implant provides rotational stability. MATERIALS AND METHODS: In the first clinical investigation ten patients underwent uncemented total hip arthroplasty between January 1999 and May 1999 using the CR-stem((R)) (Implantcast GmbH, Buxtehude, Germany). Results were investigated using the Harris-hip-score (HHS) and antero-posterior and lateral radiographs. Migration was evaluated with the EBRA-FCA-method with a follow-up of 7 years. RESULTS: We demonstrated a mean subsidence rate of 2.23 +/- 1.13 mm 7 years after implantation thus providing basic data for extensive testing in a clinical environment. DISCUSSION: As small subsidence rates are regarded as predictor for superior long-term results in uncemented total hip arthroplasty according to the literature, the CR-stem shows promise for excellent long-term results.

Endothelial iNOS versus platelet iNOS: responsibility for the platelet/leukocyte endothelial cell interaction in murine antigen induced arthritis in vivo.

OBJECTIVE: Since an increase of platelet-endothelial cell interactions has been observed in mice with Antigen- induced-Arthritis (AiA) as well as an increase of NO expression, the aim of our study was to investigate in vivo the influence of NO, especially the platelet and endothelial inducible NO Synthase, on the platelet- and leukocyte endothelial cell interaction. MATERIAL AND METHODS: C57/Bl6 mice and iNOS deficient mice were disposed in 6 groups (each=7). After induction of AiA, rolling and adherent fluorescence labelled platelets and leukocytes were investigated by intravital microscopy (IVM) on day 8 after AiA. Rank SUM Test and ANOVA on ranks have been performed regarding the data. RESULTS: All arthritic mice presented an increase in platelet and leukocyte interaction with the endothelium compared to control groups. The arthritic iNOS deficient mice showed a more intense interaction of platelets and leukocytes with the endothelium in comparison with the wild-type arthritic mice. The group using arthritic wild-type recipient and iNOS deficient donor mice showed an increase in cell-interactions, leading to an endothelial effect, compared to the group using iNOS deficient arthritic recipient and wild-type donor mice. CONCLUSION: The IVM data lead to an anti-inflammatory effect of NO, since NO followed an increase in platelet- and leukocyte- endothelial cell interaction in iNOS deficient mice with AiA. In addition, we have shown for the first time in vivo that platelet NO produced by iNOS seems to have a minor influence on the leukocyte induced tissue damage in contrast to endothelial iNOS. Therefore, selective platelet inhibition would not interfere with the protective effect of NO.

Percutaneous cryodenervation of lumbar facet joints: a prospective clinical trial.

Facet joint pain is an important aspect of degenerative lumbar spine disease, and radiofrequency medial branch neurotomy remains an established therapy, while cryodenervation has still been poorly examined. This study was undertaken to examine the effects of medial branch cryodenervation in the treatment of lumbar facet joint pain. This was a prospective clinical case series. Patient selection was based on the history, physical examination and positive medial branch blocks. Percutaneous medial branch cryodenervation was performed using a Lloyd Neurostat 2000. Target parameters were low back pain (VAS), limitation of activity (McNab) and overall satisfaction. Fifty patients were recruited, and 46 completed the study. The follow-up time was 1 year. At 6 weeks, 33 patients (72%) were pain free or had major improvement of low back pain; 13 (28%) had no or little improvement. Including failures, mean low back pain decreased significantly from 7.7 preoperatively to 3.2 at 6 weeks, 3.3 at 3 months, 3.0 at 6 months and 4.2 at 12 months (P<0.0001). Limitation of the activities of daily living improved parallel to reduced pain. Our results suggest that medial branch cryodenervation is a safe and effective treatment for lumbar facet joint pain.

[Pre- and postoperative radioligical evaluation of knee joint endoprothesis. Orthopedist's view]. / Die prä- und postoperative radiologische Evaluation der Kniegelenkendoprothese. Aus der Sicht des Orthopäden.

The implantation of a knee arthroplasty is still a demanding operation. There is still no "golden standard" available, although a lot of guidelines have been declared. Because of this fact this article should provide the radiologist with an overview of and some background knowledge for the radiological evaluation of knee arthroplasty.

The influence of the implant size on the outcome of unconstrained total knee arthroplasty.

INTRODUCTION: The influence of implant size on the results in unconstrained total knee arthroplasty has never been investigated before. PATIENTS AND METHODS: 133 patients with unconstrained total knee arthroplasty were examined (HSS Score, Knee Society Score) with consideration of the different sizes of femoral and tibial components and the thicknesses of the tibial inlays. The medium follow up was 41.2 months (8 months to 74 months). RESULTS: Although the different component sizes gained different results, the differences were not significant. The combination of two component sizes did not lead to a significant change of the results. The results of the Knee Society Score seemed to become worse with thinner polyethylene tibial inlays although these differences were not significant. CONCLUSIONS: In conclusion, implant size had no significant influence on the outcome of total knee arthroplasty. The combination of two implant sizes showed no disadvantage.

[Macerated human hip bone preparation as a substitute for fresh frozen preparations for testing the primary stability and frictional torques of cementless hip cups]. / Mazerierte Hüftpfannenpräparate als Ersatz für fresh-frozen-Präparate zur Testung von Primärstabilität und Einschraubverhalten zementfreier Hüftpfannen.

AIM: The aim of the study was to validate macerated human acetabuli as replacement for fresh frozen preparations for testing primary stability and the screwing in moments of cementless threaded hip cups. METHOD: Three fresh frozen human pelvis were tested. One half of each pelvis was macerated whereas the other half was preserved as fresh frozen preparation. In the side of every pelvis the moments of screwing-in, the micromotions, the maximum expressing force and the maximum pull-out torque were determined. RESULTS: The screwing in moments, the maximum expressing forces and the maximum pull-out torques did not change. The micromotions were reduced to half. CONCLUSION: Considering the reduction of the micromotions, macerated human acetabuli are valid replacements for fresh frozen preparations for testing the primary stability and the screwing-in behaviour of screwed pans.