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Aim of the Study: Multiple instrument systems are currently available for the reduction of spondylolisthesis, where posteriorly oriented tensile forces are directly acting on the slipped vertebra. The aim of this clinical study was to evaluate the clinical efficacy of a new indirect reduction manoeuvre applied to the lumbar spine., Method: A total number of 32 patients (14 female, 18 male) suffering of spondylolisthesis were reduced by transpedicular instrumentation during June 2001 until October 2003. The cranial adjacent vertebra was temporarily instrumented and the reduction of the slipped vertebra was facilitated by the application of traction on the instrumentation leading to tension of the longitudinal ligaments. Posterior transforaminal lumbar interbody fusion (TLIF) or anterior lumbar interbody fusion (ALIF) was then carried out according to the degree of degenerative shortening of the anterior long. spinal ligament. On the last follow up (average 32 month postoperatively; min.: 22 month) both the reduction of the spondylolisthesis and the ossification of the interbody fusion was evaluated radiologically. Physical function and patients satisfaction was measured by means of the SF 36 questionnaire., Results: The dislocation was reduced in all cases (81% on average). At the time of the last follow up bony fusion was depicted on the radiographs in all 32 patients. A distinct improvement in all categories of the SF 36 (in 5 out of 8 categories statistic significant) could be demonstrated., Conclusion: Temporary intraoperative instrumentation of the cranial adjacent segment proofs to be a simple an effective method for the sufficient reduction of spondylolisthesis.

Introduction: The aseptic loosening of cemented total knee arthroplasties is still an unsolved problem. In this regard, the hydrolysis resistance in the metal-to-bone cement interface is of major importance., Material and Methods: Cemented pre-treated tibia components coated by means of a silica/silane interlayer system of the model "Columbus PS" were dynamically loaded with the help of a knee-simulator similar to DIN ISO 14243. After loading, the components were microscopically analysed concerning debonding in the metal-to-bone cement interface as well as with regard to cement mantle defects. These data were matched with uncoated "Columbus PS" components. Unloaded coated and uncoated tibia components acted as a control., Results: In comparison with uncoated tibia components, the pre-treated and coated ones yielded a highly significant reduction of cement defects (p < 0.01) as well as a significant reduction of debonding in the metal-to-bone cement interface (p < 0.05)., Conclusion: By means of the silica/silane interlayer system for cemented tibia components, a hydrolytic debonding in the metal-to-bone cement interface with subsequent mechanical loosening and consecutive early cement mantle failure can be significantly reduced. This could lead to an increased long-term stability of the metal-to-bone cement compound with decreased aseptic loosening in clinical use.

We present the clinical case of a decennial boy with acute leftsided hip pain without appropriate trauma. The initial diagnosis of coxitis fugax was verified in this case with inconspicuous blood parameters and X-ray by a sonographically proven intraarticular effusion. An immediate magnet resonance imaging (MRI) study of the affected hip joint was done. Here, a complete "necrosis" of the proximal femur epiphysis was verified. With knowledge of these results, an immediate operation of the hip joint with a ventral capsule incision and consecutive intraarticular decompression was performed. A complete reperfusion of the femur head was evident in the MRI scan seven days postoperatively. In accordance with this clinical case report, we would like to point out the necessity for the immediate diagnosis of indifferent hip pain by means of MRI, especially for patients in the atypical "critical age" (> or = 8 years) for coxitis fugax. This is discussed under consideration of the possible aetiopathogenesis and the current literature.

Aim: Due to several bad results of studies, titanium is no longer used as an implant material in cemented total hip arthroplasty. This study attempts figure out by means of a meta-analysis if the material titanium itself was responsible for the bad results of some studies or if specific implant characteristics contributed to implant failure, independent of titanium., Method: Studies between 1960 and July 2002 were analysed concerning failure rates of cemented titanium total hip arthroplasties regarding their specific implant characteristics., Results: Specific implant characteristics such as roughness of the surface and geometrical features led to significantly different failure rates. Stems of titanium with a dull surface and a wide proximal geometry could achieve such good results as those of the cobalt-chromium stems published in the study results of Malchau., Conclusion: Titanium is justified as a cementable material in total hip arthroplasty. By respecting specific implant characteristics, very good failure rates can be achieved. The high failure rates, published in several studies, are based upon implant characteristics which are not suitable for cementing techniques and not upon the implant material titanium itself.

Aim: This study presents the results of arthrodesis of the ankle in non-inflammatory osteoarthritic conditions., Method: 34 open arthrodeses (33 patients) were followed for 5.5 +/- 3.2 years after surgery. At follow-up clinical results were evaluated by the Kitaoka and Gruen scores and standing X-rays were analysed for the talo-calcaneal angle and the grade of arthrosis., Results: Patients expressed high and very high satisfaction in 84 % of the cases; good results were higher with the Gruen score (79 %) than with the Kitaoka score (50 %). The patients did not complain pain but had some limitation in walking distance; gait was compensated in 44 % of the patients. A significant increase of arthrosis in adjacent joints could not be observed. A pseudoarthosis was observed in four cases and minor, conservatively treated complications arose in seven cases., Conclusion: We conclude that, on the basis of these results, arthrodesis of the ankle still has a place in therapy due to the high patient satisfaction.

Introduction: We present prospective medium-term results of the modular revision prostheses "MRP-TITANIUM"., Material and Methods: 45 patients (n = 48 prostheses) were evaluated. The mean follow-up was 4.7 years (min.-max.: 1.0-9.0 years). Pre- and postoperatively the Harris hip score (differentiated to Paprosky I-III) was examined. 66.67 % of the cases had extensive bony defects (> or = Paprosky II b). By means of X-ray examinations, the stability of the prostheses, periprosthetic bone remodelling, the presence of radiolucent lines as well as bone defect regeneration were assessed postoperatively., Results: The mean Harris hip score improved from 25.6 preoperative to 71.4 postoperative (p < or = 0.05). In 44 cases the X-ray showed stable fixation without secondary migration. In one case the stem (stand time 2.36 years) was revised due to secondary migration (> or = 5 mm). The survival rate (Kaplan-Meier) was 97 %. Bone transplantation with consecutive defect regeneration was (n = 30) complete in all cases. In six cases (12.5 %) a postoperative dislocation occurred with subsequent successful closed reposition four times (8.3 %). In two cases (4.2 %) an open reposition was done with correction of the antetorsion angle of the prostheses., Conclusion: The "MRP-TITANIUM modular revision prostheses" has proved to be reliable in cases of revision surgery with extensive bony defects. The failure rate was 2.1 % for 48 prospectively examined prostheses.

Aim of the Study: Degenerative changes of the motion segments are accompanied by an increased vascularization of the endplates. Nerve elements have been demonstrated in the environment of the endplate vessels, which might play a role in pressure related pain sensation. In order to investigate this theory we compared and correlated the extent of memory pain as determined by discography with the amount of vascularization in the endplates on histological examination., Method: Discography was performed in 32 Patients (21 female, 11 male), who underwent spinal fusion. The extent of pain sensation was determined on a self reported visual analogue scale ranging from 0-10 Points. Bone chips from the anterior vertebral endplates were obtained during surgery. Decalcified paraffin-embedded samples were then immunostained with the vascular endothelial marker CD 34. The quantification of endothelium as part of the whole cross section area was performed by means of a computerized optical method., Results: The extent of the pain sensation during discography ranged from 0-9 points on the VAS (average: 5.3 points, SD 3.1). On the histological quantification the total endothelial area per observed field varied from 0.04 to 7.39 % (average: 2.19 %, SD 1.62). The comparison of the pain extent on discography and the vascularization of the endplate resulted in a correlation coefficient after Spearman of rho = + 0.64 (p=0.0006)., Conclusion: The extent of vascularization in the degenerated endplates of a motion segment shows a moderate correlation with the self reported VAS scores after discography. Further investigations will have to clarify, whether neurogenic structures originating from vascular endothelium yield a better correlation to discogenic pain.

Aim: Computer-assisted cement removal out of the femoral medullary canal requires the exact definition of the plug's shape within a 3D coordination system. Aiming at a sufficiently precise reconstruction based on segmentation of just a few 2D X-ray images a special mathematic procedure is needed for automatic surface interpolation. The geometric specification of the resulting virtual model should take into account the characteristic geometry of the navigated tools in order to achieve the best possible removal., Method: Studies were performed on anatomic specimens of entire human femora, that underwent cemented THA before being cut every 5 mm. The cross-sections were scanned at the high resolution of 600 dpi. Segmentation of the cement was performed with the help of a virtual deformable template and was both used for simulation of X-ray projections from various points of view and for validation of the reconstructed 3D model. By this means systematic errors such as those possible during X-ray acquisition, tracking or segmentation could be avoided and the precision of the procedure could be measured exclusively., Results: With increasing number of X-rays the distance from the reconstructed 3D model to the original could continuously be reduced. Using only two x-rays a maximum error was measured with 6.5 mm, whereas 5 pictures taken from different angles showed to be enough to ensure an error below 1 mm in the distal part of the femur. By the use of 6 or more pictures no significant improvement could be attained., Conclusion: The innovative procedure is essential for future 2D image-based fluoroscopic navigation of PMMA removal and bears the options of computer-controlled and robotic material working, respectively.

Aim: The purpose of this study was to examine the FDG-PET in respect of its diagnostic valency with regard to septic/aseptic loosening of lower limb prostheses., Method: 28 patients with 41 lower limb prostheses were examined by means of FDG-PET to evaluate septic/aseptic loosening of their hip prostheses. Therefore, a differentiated FDG-PET result interpretation subdivided into five categories was developed. The final diagnosis was based on operative findings with following culture and histological outcome., Results: The worked-out categories showed a high agreement to the intraoperative macroscopic and histological results (n = 23 correctly positive, n = 1 false positive, n = 1 correctly negative and n = 3 false negative)., Conclusion: With a subtly differentiated interpretation (categories I - V) of the qualitative glucose metabolism safe statements can be made regarding septic/aseptic endoprostheses loosening. This was impressively confirmed by the agreement of the FDG results with the histological results.

Aim of the Study: Osteoporotic vertebral fractures are an ailment of the aging population of increasing incidence and high socioeconomic impact. Intractable pain causing significant morbidity leads to long-term hospitalisation. Kyphoplasty offers a new minimal invasive operative stabilisation procedure for these vertebral compression fractures. This study is conducted to investigate whether this procedure significantly reduces both pain and the duration of hospital stay in comparison to conservative treatment modalities., Method: From January until July 2002 a total of 22 patients had undergone kyphoplasty in 37 vertebral bodies. Osteoporotic vertebral fractures were treated in 18 cases, while in another 4 cases prophylactic stabilisation for osteolytic lesions was performed. Both the duration of hospital stay and the reduction of pain symptoms were determined and compared to a conservatively treated control group of 20 patients suffering from 35 fractured vertebral bodies. Pre- and postoperative endplate angles were measured to assess the restoration of the sagittal alignment. The effects on pain symptoms were measured on a self-reported Visual Analogue Score Scale., Results: The mean pain relief for the patients undergoing kyphoplasty was 82 %, which was significantly higher (p < 0.0001) compared to the group of the conservatively treated patients (42 %). Reduction of the kyphotic deformity was achieved in 4 cases (average 8.5 degrees ). The average in-patient treatment duration for the surgical treated patients was 10 days as opposed to a significantly longer mean hospitalisation of 20 days (p = 0.003). Cement extravasation was observed in 5 out of 37 treated vertebral bodies without clinical sequelae., Conclusion: Kyphoplasty is a safe minimal invasive procedure for the stabilisation of osteoporotic vertebral fractures leading to a statistically significant reduction both of pain status and duration of hospitalisation.

Aim: Due to the narrow access to the talar dome and the proximity of osteochondritic lesions to the joint surface, the therapeutic retrograde drilling often requires multiple attempts and repeated intraoperative X-ray-control. The advantages of a fluoroscopy-based computer-assisted navigation system regarding efficient planning and easy performance of the ideal drill path are evaluated in respect to accuracy and radiation exposure, as well as to time requirements., Method: A 5 mm spherical target was subcortically implanted in the medial aspect of the talar dome of 16 human cadaver specimens. Free-hand drilling was performed using the FluoroNav TM system in one group and conventional repetitive C-arm control in the other. The computed evaluation of the operative results was realized in a CT-generated 3D-model with the help of the DISOS planning and calculation program. The distance of the tip of the drill to the center of the lesion was measured, as well as X-ray exposure and total operating time., Results: The CAS procedure missed the lesion only once. The mean deviation of the computer-guided drill path was measured to be 2 mm, whereas the conventional method led to a mean distance of 5 mm from the target. Conventional drilling failed to reach the target in 5 cases, violating the articular cartilage twice. Navigation reduced the traditionally required multiple attempts of the intervention to just one drill canal and reduced radiation time to 25 %. Despite the increased technical preparation required, the navigated procedure only exceeded the conventional operating time by 2 minutes., Conclusion: Thanks to the significantly increased accuracy, fluoroscopic navigation offers a high degree of safety and efficacy for this minimally invasive procedure. The operation can easily be performed successfully causing only minimal collateral damage to the bone, preserving the joint surface. The inherent risks of the retrograde drilling of osteochondritic lesions are lower with navigation, while the radiation exposure of the patient and the staff is significantly reduced.

Aim: In cemented total hip arthroplasty cup loosening occurs earlier than stem loosening in most of the cases. This is mainly caused by the lack of stabile adhesion between the hydrophobic bone cement and the hydrophilic bone surface of the acetabulum. The aim of this study was to develop a multilayer amphiphilic bonding system which prevents the hydrolytic debonding at the bone cement-bone interface, thus optimizing the compound stability., Method: In a first series of tests a standardized three-point-bending test was performed to determine the compound stability of the bone cement-bone interface. The bony test specimens were immersed into physiologic NaCl solution to simulate the hydrolytic in situ conditions and contaminated with blood to simulate the intraoperative bleeding of prepared acetabular bone surfaces. In a second series of tests polyethylene cups were implanted into the acetabular cavity of sheep using the current cementing technique. Acetabular bone stock was prepared differently (subchondral sclerotic zone preserved vs. removed, additional drilling into the acetabular roof, with vs. without the multilayer bonding system) in intra-individual comparison of both acetabular sides. To ascertain the bone cement-bone stability a torsional-turn out test was performed on an universal testing machine., Results: In the three-point-bending tests the compound stability between bone cement and bone was 50- to 100-times higher with the use of the multilayer system. In the torsional-turn out tests the compound stability showed in mean a 1.8-fold increase of the interface strength in case of preconditioned acetabular cavities with the multilayer bonding system., Conclusion: The developed multilayer bonding system optimizes the interface strength between acetabular bone stock and bone cement significantly for cemented cups in total hip arthroplasty. In contrast to cementing techniques with complete removal of the subchondral sclerotic zone (in order to optimize micro-interlocking) the biologically effective and load bearing acetabular bone stock can be preserved using the newly developed multilayer bonding system. This aspect might be highly important especially with regard to possible acetabular bone defects caused by the process of aseptic cup loosening.

Aim: The aim of the study was to describe first experiences using FDG-PET in the examination of painful arthroplasties., Method: 12 patients prior to revision of a total hip or knee joint replacement underwent PET. Histopathology, microbiological analysis and intraoperative diagnosis were compared to preoperative PET findings., Results: The analysis of intraoperative findings, of microbiological examinations and of histopathology showed that besides the well known determinants infection and early postoperative granulation tissue, polyethylene wear induced foreign-body reaction was a major cause for increased FDG consumption., Conclusion: In vivo imaging of marked foreign-body tissue reaction induced by polyethylene wear is feasible by FDG-PET. This observation, however, leads to reduced specificity of PET imaging for the diagnosis of periprosthetic infection.

Aim: Many orthopaedic procedures require an accurate drilling in bone. The outcome is frequently dependent on the geometric accuracy of this surgical step. The precision of such a procedure can be improved with the help of fluoroscopic navigation. Reliability, accuracy and benefit of this new method for the patient, as well as for the surgical staff, need to be analysed., Method: In a standardised in vitro trial, the drilling of a 5 mm spherical lesion implanted in an artificial femoral head was performed using a navigated drill-guide and a navigated drill. In groups A and B, the distance of the tip of the drill to the center of the lesion was analysed in a 3D CT-generated model and in macroscopic cross section. Additionally, in group B the actual direction of the drill canal was measured., Results: The mean distance in group A was measured to be 1 mm, with all results ranging between 0 and 2.5 mm. In group B the planned direction of the canal was reproduced with a deviation of 0 degrees to 7 degrees, the target only being missed by a mean distance of 2.5 mm and a maximum of 3.5 mm. Compared to the macroscopic and 3D-CT findings, the correlation of the data calculated by the navigation system was accurate up to a difference of 4 degrees or 2 mm., Conclusion: The fluoroscopically assisted freehand navigation used during the drilling of bone led to a high accuracy of three-dimensional tip placement while reducing radiation exposure to a minimum. It represents a promising and efficient application for a variety of procedures in orthopaedic surgery.

Aim: It is known that high-energy extracorporeal shock waves, focussed to the intact distal rabbit femur, induce periosteal new bone formation within the focus zone. This study was done to investigate whether there is additionally new bone formation outside of the focus zone, i. e., in the proximal femur, 10 days after shock wave application to the distal rabbit femur., Method: 18 adult Chinchilla-Bastard rabbits were randomly divided into three groups (A, B, C; each n = 6). One distal femur of each animal was focussed for shock wave application with different positive energy flux densities (A 1.2 mJ/mm (2), B 0.9 mJ/mm (2), C sham treatment). Only the proximal femur outside the shock wave focus was investigated. Here periosteal new bone formation was evaluated by fluorescent labelling. The maximum thickness was measured by means of computer-assisted image analysis., Results: Maximum ventral-periosteal new bone formation outside the shock wave focus was significantly increased in group A compared to group B (p = 0.007) or group C (p = 0.001). In contrast, the maximum ventral-periosteal new bone formation outside the shock wave focus demonstrated no statistically significant difference in group B compared to group C (p = 1.0)., Conclusion: Depending from the amount of positive energy flux density applied to distal rabbit femur a significantly increased ventral-periosteal new bone formation results in the proximal rabbit femur outside the shock wave focus.

Aim: Low back pain ranks high among the reasons for physician office visits and is costly in terms of medical treatment. A number of studies have shown that low back pain patients have significantly lower trunk strength when compared with healthy controls. The working hypothesis at the beginning of the 1990's was that low back pain patients could be treated effectively using lumbar extension exercise., Method: 21 papers and abstracts reporting on lumbar extension training are rated. Validation was performed for each paper according to the internationally accepted system of the American Association of Spine Surgery in types A-E., Results: 1100 cases from 21 publications and abstracts dealing with lumbar extension training were evaluated. We did not find a single type A study in our search. The clinical outcome of the studies was a reduction of pain, improvement of range of motion, improvement of spinal condition and of the lumbar extension strength., Conclusion: Prospective, randomized, controlled studies with long-term results should help to delineate further the role of isolated lumbar extension exercise for the treatment of low back pain and to test the efficacy compared to other methods of care.

Aim: The pigmented vilionodular synovitis (PVNS) is a tumour like disease of unknown origin that often shows recurrence. The pathogenesis is still unknown and therefore the question of the right therapy is not resolved., Material: With a case report of a patient with recurrence after two arthroscopic synovectomies, PVNS is discussed against the background of the clinical, histological, and radiological features., Results: We performed an open synovectomy and cystic lesions in both condyles of the femur and proximal tibia were filled with homologous and autologous cancellous bone. Three months later the patient had no pain and the bone density in the former cystic lesions was appropriate., Discussion: The pathogenesis is still unknown. Diagnosis often is obtained much too late due to missing specific symptoms. PVNS occurs in local forms as well as in a diffuse growth pattern. Recurrence rates of up to 78% are very high. Besides arthroscopic and open synovectomy, the treatment with radiosynoviorthesis must be considered. Depending on the growth pattern, the tumour masses, and the affected joint, the therapy has to be chosen very carefully and sometimes different forms have to be combined if a recurrence--free result is to be achieved.

Aim: In the study we evaluated the effectiveness of intraarticular injected hyaluronic acid (Hyalart) with regard to the changes in the parameters maximal isokinetic muscle strength, total work, pain at rest, and pain under toad., Method: We examined 43 patients with osteoarthritis in both knee joints (Kellgren II or II according to X-ray) in right/left comparison. We used the isokinetic system Cybex 600 for measuring the maximal isokinetic muscle strength and the total work. We used the visual analog scale for the pain. The evaluated parameters were measured before and after a 5-week treatment phase with 5 intraarticular injections (one injection per week with 20 mg hyaluronic acid)., Results: In knees treated with hyaluronic acid the mean peak torque of the knee extensor was 57 +/- 26.15/32 +/- 19.63 Nm vs. 77.17 +/- 32.54/47.83 +/- 21.43 Nm after (p < 0.01), the mean peak torque of the knee flexor was 40.44 +/- 21.58/22.89 +/- 16.64 Nm vs. 53.55 +/- 24.26/34.05 +/- 17.37 Nm after treatment (p < 0.01) at the angular velocities of 60 degrees/s and 180 degrees/s. Significant differences (p > 0.01) between treated and untreated knee were found for total work of the extensor and flexor of the knee. The pain at rest decreased from 3.83 +/- 1.72 cm to 1.36 +/- 1.42 cm and the pain under load decreased from 7.57 +/- 1.34 cm to 3.75 +/- 1.32 cm in the treated knee group (p < 0.01)., Conclusion: The intraarticular injection of hyaluronic acid is effective and safe in the treatment of patients with gonarthrosis. The treatment resulted in a functional improvement of the knee joint and had a good pain lowering effect in patients suffering from gonarthrosis.

Introduction: Early diagnosis of isthmic lumbar spondylolysis cannot always be established on plain radiographs and CT scans, only. In the case presented here, magnetic resonance imaging (MRI) showed typical bone marrow changes in T1- and T2-weighted images, even at an early stage., Case: A 11-year old female judoka complained of deep lumbar pain with local tenderness to pressure at L3 to S1. Clinically, there was no neurologic deficit. Conventional x-ray showed no abnormalities. In contrast, MRI revealed a locally ill-defined bone marrow oedema in both pars interarticularis of the 5th lumbar vertebra. This was interpreted as the typical MR-tomographic feature of occult stress fracture, which has to be seen as early evidence of isthmic spondylolysis. Complete restitution was achieved after conservative treatment., Conclusion: In early spondylolysis--presented here in form of a case report--, changes of MR signal intensity in the pars interarticularis may be detected, even before fracture lines are to be seen on plain radiographs. Further studies are necessary to confirm MRI to be the method of choice for early diagnosis.

Purpose: The hydrolytic degradation of the implant-cement interface has to be seen as the main reason for aseptic loosening of cemented total hip replacements. Therefore, a new method of conditioning the metallic surface was developed in order to achieve a hydrolytic-resistant bound stability between the implant and bone cement. Preliminary experimental data on test bodies are presented here., Method: The metallic surface of 6 pairs of cylindrical test bodies each (CoCr-alloy, circular testing surface with O 6 mm) were conditioned by the method of silicoating/silanisation to gain a covalent coupling with the applied bone cement. In order to examine the initial stability and the hydrolytic resistance of the metal-cement compound, these pairs of surface-conditioned test bodies (SCT) as well as a reference series of surface-unconditioned test bodies (SUT) were immersed for 0, 30, 90, 150 days (d) in moisture environment (physiological saline solution, 37 degrees C) after coupling with bone cement. The adhesive strength of the test bodies-(bone cement-compounds) were determined by tensile tests on an universal testing machine (Typ Z030, Zwick, Ulm) with gimbal suspension., Results: At time 0 d (that was without immersion of the test bodies) the mean maximum tensile bond strength of the SCT-cement-compounds was 39.5 MPa (SD +/- 4.7 MPa) and that of the SUT-cement-compounds 37.1 MPa (SD +/- 7.3 MPa) (p = 0.575). After immersion the tensile bond strength of the SUT-cement-compounds significantly decreased to an average of 13.5 MPa (SD +/- 2.7 MPa) (30 d), 10 MPa (SD +/- 1.7 MPa) (90 d) and 12.3 MPa (SD +/- 1.4 MPa) (150 d) (p < 0.01). In contrast, the SCT-cement-compounds showed a nearly unchanged high mechanical stability with tensile bond strength values of 37.0 MPa (SD +/- 4.9 MPa) after 30 d, 36.1 MPa (SD +/- 5.0 MPa) after 90 d und 30.2 MPa (SD +/- 4.7 MPa) after 150 d (p > 0.01)., Conclusions: With reservation as to further in vitro and in vivo investigations the increased hydrolytic stability of the metal-cement-bound of surface-conditioned CoCr-alloy test bodies promises an improvement of the long-term stability of cement total joint replacements.

Purpose: Purpose of the study was to summarize the current scientific knowledge of the interaction between rehabilitative procedures and the periprosthetic bone remodeling processes in the early postoperative phase of total hip arthroplasties., Method: In a comprehensive review of the international literature we analysed the interdependence between osseointegration, primary implant stability, relative micromotion of implant versus bone, and joint loading forces during mobilisation or physiotherapy. Accordingly, guidelines for the rehabilitation of cemented as well as cementless hip arthroplasties were established in order to eliminate factors disturbing prosthetic integration and hence provide for the best long-term stability of the implanted prosthesis possible., Results: Osseointegration of cementless implants is impossible if relative micromotions exceed > 150 microns. Furthermore, torsional stresses (i.e. alternate climbing of stairs, rising from seated position without arm support) will destabilize uncemented femoral shaft implants. Cemented prostheses may be loaded with full body weight. Uncemented implants should be loaded only partially for at least 6 weeks. Loadings of the hip joint with more than twice the body-weight (i.e. walking without crutches, physical exercise against high resistances or long levers) are to be avoided for 3 months. The transition from the three-points walking to the two-points walking technique depends particularly on the conditions of the muscles stabilizing the hip joint., Conclusion: The rehabilitation of patients after total hip arthroplasty has to be brought into line with the changed biomechanical situation, the particulars of the implants and the individual requirements of the patients.

Purpose: For patients with prostate cancer (CaP) the proof of osteoblastic bone metastases is decisive regarding the prognosis as well as the therapeutical concept. To evaluate the efficiency of skeletal alkaline phosphatase (SAP) as staging marker for bone metastases in prostate cancer, SAP was measured in CaP-patients with and without bone metastases compared with prostate-specific antigen (PSA) as the marker of choice till now., Method: 73 patients with histological proven, but still untreated CaP were entered into the study. After staging the patients were divided into 3 groups: group I: patients with CaP and bone metastases (n = 21), group II: patients with locally advanced CaP without bone metastases (n = 26), group III: patients with clinically localized CaP without bone metastases (n = 26). Serum concentration for SAP and PSA were determined using radioimmunassay. As reference range we defined serum concentrations for SAP < 19 ng/ml and for PSA < 100 ng/ml., Results: 71% of the patients with bone metastases (group I) showed elevated SAP and PSA serum concentrations. In contrast, patients without bone metastases (group II + III) have normal SAP-values (<19 ng/) and in 19% of the cases elevated PSA-values (>100 ng/ml). This resulted in a sensitivity and specificity of 71% and 100% for SAP and 71% and 81% for PSA. The positive predictive value for osteoblastic bone metastases was 100% for SAP and 60% for PSA., Conclusion: SAP is a useful staging marker in prostate cancer and can contribute for an early detection of osteoblastic bone metastases.

Purpose: Aseptic loosening of prostheses implants is the most common complication of hip replacement surgery and represents an increasing problem because of still rising numbers of primary arthroplasties. This study reviews the current scientific status of causes, diagnosis and therapeutical concepts on this theme in literature., Method: We analyzed 6,386 cases on aseptic hip revision arthroplasties published in the international literature and separated the results for cup and femoral components. On this basis we deduced some recommendations for the operative procedure in aseptic hip revision surgery., Results: The mean follow-up time of all studies was 6.8 years in the case of cemented and 4.0 years in the case of uncemented hip revision arthroplasty. As an average rate of rerevision, 15.1% was calculated for cemented cup revisions, 4.3% for uncemented cup revisions. Rates of aseptic loosening were 23.1% for cemented procedure, 8.8% for uncemented cup implants. Femoral revision implants showed an average aseptic loosening rate of 21.2% for cemented procedures and an average rate of rerevisions of 12.7%; uncemented procedures showed aseptic loosening in 4.4% of the cases and rerevision in 5.5%. For old, relatively immobile patients with reduced physical constitution, cemented reimplantation has still to be regarded as the method of choice. In young patients uncemented revision arthroplasty is to prefer both on the acetabular and the femoral side to achieve superior results with good long-term prognosis. Regarding the bony defects induced by loosening, bone grafting is recommended for cemented and uncemented reimplantation technique., Conclusion: In the case of aseptic hip revision arthroplasty, the therapeutical procedure has to be adapted especially to the age and general constitution of the patient as well as to the bony defects induced by prosthetic loosening. For the future, controlled studies should respect the initial condition of primary as well as revision arthroplasty in reporting the results.

Purpose: In the case of hip revision arthroplasty, cementless implants combined with bone grafts are increasingly used to reconstruct the acetabular bone stock. The study on hand reports about the results with the trabecular orientated cup implant of CopflHolz after 10 years of application., Method: A total of 256 hip revision arthroplasties were prospectively recorded with a mean follow-up period of 5.6 years. For the osseous augmentation of the acetabulum, autogenous bone was used in 227 cases, allogenic spongy bone in 15 cases and mixed bony materials in 8 cases. The clinical and radiological follow-ups were done after 3, 6, 12 months and then in 2-years intervals., Results: Within the 10 years follow-up 3 rerevisions must be done because of deep infection, 6 rerevisions because of aseptic loosening or primary instable fixation. The specific failure rate of the used cup implant amounts to 96.2% five years after revision arthroplasty, and 86.8% ten years after revision arthroplasty. Revealed from a radiological point of view, the transplanted spongiosa showed in 83.5% a complete osseous integration one year after the operation. Worse incorporation was conspicuous especially when allografts or mixed bone grafts were used. Clinically, a permanent improvement of motion, pain and walking ability was seen postoperatively. 91% of all follow-up patients were satisfied with the result of the revision arthroplasty., Conclusions: The trabecular orientated cup implant has proven itself worthy for cementless cup revision arthroplasty and will be an alternative to the cups and rings used up to now for the reconstruction of great acetabular bone deficiencies.